Lacrimal Drainage Surgery
JAMES A. KATOWITZ, SCOTT M. GOLDSTEIN, FEMIDA KHERANI and JOANNE E. LOW
Table Of Contents
EVALUATION OF EPIPHORA|
ACQUIRED LACRIMAL PROBLEMS
|Epiphora is a sign of an imbalance between tear production and drainage. Examination of the patient with epiphora reveals either an overproduction of tears or decreased drainage through the nasolacrimal system. Obstruction of the tear drainage system can be congenital or acquired and may occur at any level along the system. Patients may present with epiphora as well as other problems such as dacryocystitis. Congenital obstructions are typically caused by imperforate lacrimal systems. Acquired obstruction may be secondary to previous surgery, radiation, chronic inflammation or trauma. Involutional and medication-induced changes may also contribute to nasolacrimal duct obstruction. Regardless of the etiology, the principles of surgical repair are the same. This chapter reviews the common problems of lacrimal drainage and their current evaluation and management modalities, emphasizing surgical treatment.|
|EVALUATION OF EPIPHORA|
|When a patient presents with epiphora, it is important to determine the
etiology of tearing. The tearing may be a result of external disease
including tear film, corneal, lid, or lash anomalies, or the result of
nasolacrimal obstruction. It is convenient to divide lacrimal obstruction
problems into congenital versus acquired problems and to distinguish
upper system (proximal) from lower system (distal) obstruction (Fig. 1). The upper system is defined as the area extending from the external
puncta through the canaliculi, to the common internal punctum in
the lacrimal sac. The lower system includes the lacrimal sac through the
valve of Hasner.|
Information regarding the nature of tearing—amount, frequency, associated mucopurolent discharge—and presence of a periocular mass is useful. Examination of the medial canthal area is necessary. Any redness, swelling, discharge, or skin changes should be noted. Because two thirds of the lacrimal sac lies below the medial canthal tendon, a mass that is located above this tendon may indicate an anterior ethmoidal mucocele, intraorbital tumor, or nasofrontal encephalocele. Expression of mucoid material retrograde through the puncta with pressure on the lacrimal sac may confirm the presence of nasolacrimal obstruction or stenosis. Several clinical tests, including the dye disappearance test (DDT) are useful tools. These tests are outlined later in this chapter.
Most adults who report epiphora do not have an obvious overflow of tears. More frequently, there is an increase in the height of the tear meniscus between the lower lid and the cornea. Obstruction to the flow of tears can lead to secondary blepharoconjunctivitis at any age. Canaliculitis occurs more commonly in adults, and is usually related to dacryoliths or casts obstructing flow which can result in infection. Severe cellulitis caused by infection of the lacrimal sac (dacryocystitis) also can occur.
Lid margin abnormalities can produce epiphora, especially as an involutional phenomenon. Ectropion, particularly of the lower punctum, obviously can lead to overflow of tears. Lid laxity alone, however, may interfere with the lacrimal pump mechanism or produce exposure with secondary reflex tearing. In adults, use of the Jones dye tests may also be helpful. In our experience, the combination of the DDT, lacrimal irrigation, and inspection of lid anatomy provides the necessary information in most instances. If there is any suspicion of tumor in the sac or drainage pathways, a dacryocystogram (DCG), magnetic resonance imaging (MRI) or computed tomography (CT) scan should be performed. Entropion can stimulate reflex tearing through irritation of the globe by the lashes. Similarly, trichiasis and distichiasis may produce epiphora.
One of the most common sources of confusion is evaluating adult tearing given an apparently open lacrimal drainage system. This tearing is typically a reflex response resulting from a dry-eye or sicca problem. For this reason, it is especially important to evaluate baseline tear production properly. Observation of the tear meniscus, tear breakup time, and Schirmer's testing are important in assessing the adult lacrimal system because aggressive opening of drainage in the face of a dry eye can lead to more significant problems. The DDT is especially helpful in children.1,2 The traditional Jones dye tests are more useful in adults.3–5 Dacryocystography and lacrimal scintigraphy also are of value, especially in excluding functional blocks when the nasolacrimal system is open to irrigation. All of these tests are described in detail elsewhere,6 but a brief review may be useful as an introduction to the surgical management of acquired lacrimal drainage problems.
Observation is the most basic tool available to the clinician. The level of tears should be noted. In addition, the position of the lids and the apparent functioning of the lacrimal pump mechanism should be assessed. Pressure on the lacrimal sac may provide additional information indicating a mucocele or true infection of the lacrimal sac. Material expressed in this fashion can be sent for smears and appropriate cultures and sensitivities although this is not a necessity.
EVALUATION OF BASELINE TEAR PRODUCTION
In addition to observation of the tear meniscus, the basal tear secretion test (BTST) with the use of a topical anesthetic is essential.7 Less then 10 mm of wetting of filter paper (Schirmer, Whatman number 41, 35-mm long, 5-mm wide) over a 5-minute period indicates a potential problem in baseline tear production. Evaluation of the tear film can be useful in assessing the role that decreased baseline tear secretion or changes in the tear film may play in stimulating reflex tearing. A tear break-up time (TBUT) below 10 seconds indicates tear film instability.
IRRIGATION AND PROBING
Probing in the adult should be limited to the puncta, canaliculi, and proximal lacrimal sac. Gentle dilation of the external puncta should be done and the lacrimal cannula should be passed carefully in each canaliculus. Initial passage should be in a vertical direction, entering the ampulla for 2 mm, and then moving medially with the eyelid on lateral traction. Attention should be given to veils or strictures, especially at the internal common opening. Once inside the lacrimal sac a hard stop is felt against the bony medial wall. Irrigation of the system should then be undertaken. Regurgitation from the opposite canaliculus not only indicates the relative patency of the opposite canalicular system but also indicates a lower system block in either the lacrimal sac or the nasolacrimal duct. Probing of the nasolacrimal duct in an adult should be avoided because it often is painful, even with use of a local anesthetic injected through the sac and duct. More importantly, it rarely yields more than temporary relief of symptoms. Examination of the nose should be done to exclude impaction of the inferior turbinate, a deviated septum, or the presence of an intranasal neoplasm that obstructs the exit of tears from the nasolacrimal duct. Examination may be facilitated by endoscopic instrumentation.
DYE DISAPPEARANCE TEST
The DDT is a simple test in which a single drop of 2% fluorescein is instilled into the anesthetized cul-de-sac of each eye.3,8,9 Excess fluid or overflow is wiped away, and the tear meniscus observed over a 5-minute period. In a normal eye, the tear meniscus will become relatively unstained within 5 minutes. In patients with lacrimal obstruction, the stained meniscus will either increase in height or be diluted only slightly (Fig. 2). Retained dye in the tear meniscus can be graded from trace to 4+. This is an excellent quantitative test to measure lacrimal drain function, especially in children. As children sit on their parent's lap, the DDT can be measured via the cobalt blue filter of the slit lamp opened wide and held at a distance of 2 or 3 feet from the child. Children are typically fascinated by the light and this less-threatening distance will permit observation.
JONES DYE TESTS
Jones dye tests have traditionally been the most accepted method for the office evaluation of lacrimal function. However, they are tedious to perform and have a high false-negative rate. Furthermore, similar information is obtained from the DDT and irrigation of the nasolacrimal system. For the primary Jones test, a drop of 2% fluorescein is placed into the conjunctival cul-de-sac on one side.5 The inferior turbinate near the lateral floor of the nose is then sprayed with a topical anesthetic and decongestant, such as 4% cocaine. A small wire with cotton wrapped around the end or a cotton-tipped applicator (Calgiswab, Biomedical Division, Inolex, Glenwood, IL) is placed under the anterior half of the inferior turbinate. In 5 minutes, the cotton is removed and examined for staining, which indicates that flow through the lacrimal system is normal. If the dye does not stain the cotton, a functional nasolacrimal block may be present. The secondary dye test (Jones II) is performed by irrigating in the inferior canaliculus with saline and collecting the used solution in a small basin. The patient holds the basin in front of the appropriate nostril, with the head tilted forward. If the irrigated fluid is not stained with fluorescein, the dye has not passed into the canaliculus. This finding confirms the presence of a functional block.
The DCG is a diagnostic radiologic test that uses radiopaque material that is injected with a syringe through a lacrimal cannula and into each lower canaliculus.10,11 Baseline anterior-posterior and lateral films are taken of the orbit. The dye is then injected on each side. A repeat anterior-posterior film and an oblique film are taken and then repeated at 15 and 30 minutes. The oblique position is used so that the lateral views of each nasolacrimal system are not superimposed after injection of the dye. This test can outline fistulae, diverticulae, mucoceles, neoplasms, and casts of the sac. In addition, slow clearance of the dye at 30 minutes can be helpful in confirming the presence of a functional block. In the pediatric age group, this test must be performed under general anesthesia, and the anesthesia combined with the supine position of the patient produces a nonphysiologic study in these cases. Modifications of the original DCG technique have been developed as macrodacryocystography (MDCG), subtraction MDCG, and digital subtraction MDCG.12,13 The original technique clearly shows only the lacrimal sac. The modifications include intubation of the canaliculi, macrography (enlargement of image size), and subtraction (to allow better visualization of structures); these modifications enable visualization of the entire system. Standard x-ray subtraction can involve problems with tube positioning, inadequate filling with contrast, and delay in development and subtraction. Digital subtraction, which uses angiographic equipment with fluoroscopy, eliminates these above problems. Most recently, CT scans have been used to perform DCG and can also be useful in identifying lacrimal pathology.
Lacrimal scintigraphy (or dacryoscintigraphy) uses a radioactive tracer to evaluate nasolacrimal drainage. It was first described by Rossomondo and associates in 1972,14 and since that time, many studies have shown its clinical usefulness in the evaluation of nasolacrimal disorders in both pediatric and adult patients.15–17 Placing a controlled drop of radiologic tracer in the tear film (100 μC of sodium pertechnetate) allows the tear flow to be observed and measured with a gamma counter.11,14,18 The flow is visualized on an oscilloscope. Lacrimal scintigraphy is helpful in identifying the site of obstruction, confirming decreased transit time in functional blocks, and quantifying tear drainage. Dacryoscintigraphy has the advantages of being noninvasive and physiologic.
|The most common congenital lacrimal problems involve disturbances to tear
flow through the nasolacrimal duct, and the most common presentation
is epiphora, with or without mucopurulent discharge. Other congenital
lacrimal problems may manifest as abnormalities of the puncta or canaliculi, external
fistulae (supernumerary or anlage ducts), mucoceles (amniotoceles), and less commonly, acute neonatal
DACRYOSTENOSIS AND OTHER LOWER SYSTEM BLOCKS
Dacryostenosis may be defined as a partial or complete block in the nasolacrimal duct. The most common cause of this problem is the failure of canalization of the duct at the mucosal entrance to the inferior meatus of the nose, the valve of Hasner. Although, complete osseous obstruction can occur, especially in association with anomalous passages, relative narrowing causing decreased tear flow is a more common occurrence.19–22 Abnormalities within the nasal passages, such as deviation of the nasal septum or impaction of the inferior turbinate on the valve of Hasner, also may contribute to the obstruction of the duct.23 Examination of the nasal anatomy and a working association with an otolaryngologist are both useful.
Dacryostenosis should be managed conservatively whenever possible.24,25 The traditional approach has been to combine massage of the nasolacrimal sac and duct with topical instillation of an antibiotic.20,26 Parents must be carefully instructed as to how to perform lacrimal sac massage properly.22,27 The parent should be shown how to slide the fingertip in an inferior direction, placing moderate pressure over the sac and duct, and using the antibiotic ointment as a lubricant. This motion should be demonstrated on the parent's own face as well as on the child. Some physicians prefer using the antibiotic drop because there is some thought that slowly dissolving ointment bases in the nasolacrimal duct may in fact contribute to obstruction. However, the ointment form can be used if it is more acceptable to the infant. We usually recommend an antibiotic ointment for massage, which also can act as a lubricant. If crusting and discharge are present, the antibiotic ointment can be applied several times daily to the conjunctival cul-de-sac.
Medical management is utilized until age 1 at which point surgical intervention is undertaken. Probing and irrigation is the main treatment. When this fails, Silastic intubation or balloon dacyroplasty may be used. If this fails, a dacryocystorhinostomy is the ultimate management. These procedures are discussed further later in this chapter.
PUNCTAL VEILS AND ATRESIA
Children with congenital epiphora may lack a patent opening into the lacrimal system. An astute physician may be able to discover the lack of a punctum in the office. However, it is more common in children to discover punctal veil or atresia at the time of probing surgery. When approaching these cases, careful inspection of the puncta using magnification is most helpful. In the setting of a veil, the punctum grossly appears normal, a punctal dilator or probe will not enter the system because a membrane covers this opening. A safety pin or sharp dilator can be used to “pop” into the system. In punctal atresia, the subtle elevation of the puncta on the lid margin is absent. On close inspection, there is no obvious opening to be found. Absence of a punctum often indicates absence of the canaliculus as well. Thus, a cut-down may or may not be helpful. If one punctum is patent it is best to leave the system alone. If both puncta on a given side are missing, a cut-down procedure in the area of the canaliculus or retrograde dissection from the lacrimal sac can be attempted. A conjunctivodacryocystorhinostomy may ultimately be required.
CONGENITAL LACRIMAL FISTULAS
A congenital lacrimal fistula is most likely the result of canalization of a portion of epithelial cord that extends from the lacrimal sac to the surface of the skin. Most fistulae originate from the lacrimal sac, but some originate from the common canaliculus or nasolacrimal duct. Simple excision of the fistulous tract has been successful in most cases.28 Other authors have recommended cautery of the fistula and excision of the fistula with dacryocystorhinostomy (DCR). Recommendations have also included DCR with common canalicular dissection, fistula excision, and canalicular intubation in certain situations.29,30
Most of the time it is not necessary to perform probing surgery before 1 year of age. One exception is a congenital mucocele, or amniotocele.31 This term refers to a sterile accumulation of mucus or possibly amniotic fluid trapped in the nasolacrimal sac due to a one-way valve effect at the end of the nasolacrimal duct. Fluid can enter the sac, but with poor exit of accumulated fluid, the dilated sac is seen as a bluish mass inferior to the medial canthal tendon. This swelling frequently is misdiagnosed as a hemangioma.19 In cases of congenital dacryocele without signs of infection, one approach is to massage the lacrimal sac in an attempt to open the obstruction. Massaging too vigorously, however, may rupture the dilated lacrimal sac and may consequently cause an orbital cellulitis. Parenteral antibiotic therapy and management similar to an acute dacryocystitis may ultimately be required.
Acute dacryocystitis of the newborn is an indication for office or bedside probing of the nasolacrimal duct (Fig. 3).19,26,32 In this instance, there are other signs of inflammation, and there also may be associated fever and an elevated white blood cell count. The lacrimal sac can be tapped with a turberculin needle and syringe (Fig. 4)33 to create a fine opening that will not fistulize, as can occur with a knife incision, and allows smears to be taken immediately for early diagnosis. Likewise, material for culture and sensitivity can be obtained so that specific antibiotics can be identified. Decompression of the sac is achieved immediately, which gives relief of symptoms. Furthermore, with the needle in position, the syringe can be changed to instill 0.5 mL of a bactericidal antibiotic drop. A broad-spectrum antibiotic is given intravenously until a more specific antibiotic can be identified by the cultures and sensitivities obtained from the tap. After several days, when the acute inflammation subsides, bedside probing is valuable in most cases because it usually opens the duct and allows tear drainage so that repeat dacryocystitis will not occur. Probing must be done gently, using a small probing instrument, such as a number 000 or 0000 size Bowman probe. However, if dacryocystitis recurs after such probing, a DCR may be required to avoid further infection. DCR is usually performed early if the dacryocystitis is refractory to medical management (Figs. 5 and 6).
Several studies have demonstrated a high success rate of DCR in the pediatric age group, equaling that of the adult population.34,35 Another consideration in DCR surgery at a young age is the potential for disruption of nasal bone growth. The surgery does not disturb any growth plates, and we have not seen any effect on facial symmetry after DCR, even when performed bilaterally at a very early age.
|ACQUIRED LACRIMAL PROBLEMS|
|Involutional changes can cause stenosis of any part of the lacrimal drainage
system. There appears to be a balance between a decrease in tear
production and a decreased capacity for the nasolacrimal system to drain
tears. Problems occur when these changes are out of balance. Thus
it is always necessary to evaluate both the tear production and drainage
in adult patients with epiphora. Punctal stenosis is one of the more
obvious involutional changes and it is easily visible. Similar changes
are likely occurring throughout the lacrimal system. Stenosis or complete
obstruction in the nasolacrimal duct is also a common cause of
epiphora. A functional block secondary to lid laxity and pump dysfunction
can also occur in older patients.|
PUNCTAL AND CANALICULAR STENOSIS
Adult patients with punctal stenosis will present with complaints of tearing. Close inspection will reveal stenosis that becomes more obvious during diagnostic probing and irrigation of the proximal lacrimal system. Wide dilation may suffice for acquired punctal and canalicular stenosis, but more frequently, some form of punctoplasty may be required. Several procedures are advocated. The punctal and canalicular portion of the lacrimal pump mechanism should be preserved, if possible. A variety of snip procedures have been advocated. The two-snip procedure works well to provide sufficient opening while preserving enough capillarity to allow the pump mechanism to function (Fig. 7).
Stenosis can occur from involutional causes as well as from viral infections, such as herpes and varicella. Stenosis may also be the result of the toxic effects of certain topical medications. These include epinephrine-based products or long-acting anticholenergic agents used in the treatment of glaucoma.36,37 Systemic chemotherapy can also induce canalicular stenosis,38,39 which can be preemptively treated with Silastic intubation prior to starting therapy.
Canalicular stenosis is a much more serious surgical problem. For generalized but mild stenosis, Silastic intubation may suffice. If the obstruction is severe, however, a bypass procedure with the insertion of a Jones-type Pyrex tube combined with a DCR, will likely be required. Localized canalicular obstruction in the lateral half of the canaliculus may respond to Silastic intubation combined with a DCR. Anastomosis of the common internal punctum or canaliculi with the use of microsurgical techniques has been recommended. In severe cases, however, the bypass tube may be the only successful method for curing this problem.
Interestingly, some patients with dry-eye syndrome benefit from punctal or canalicular stenosis. This condition prevents the inadequate tear film from draining, increases the corneal surface tear contact time, and can improve symptoms of dry eye, including the secondary hypersecretion of tears. Correspondingly, several methods of punctal occlusion have been devised for patients with dry eye that is not relieved by lubricants who do not have anatomic stenosis. We prefer to begin with temporary collagen plugs placed in the puncta.40 These plugs dissolve over 1 to 2 weeks. If these plugs improve the symptoms, removable punctal plugs (Eagle Vision, Memphis, TN, and FCI, Marshfield, MA) can be placed. Occasionally, these plugs cause local discomfort or extrude, but in most cases, they are successful in relieving symptoms. Alternatively, cautery or Nd:YAG laser can be used to seal the inferior puncta. Of course, this treatment is not easily reversible.
Localized painful swelling of one canaliculus can occur (Fig. 8A). Typically, as the canaliculitis worsens, the puncta becomes involved and is often referred to as a pouting puncta (Fig. 8B). Frequently, the infection is related to an acute actinomyces israelii infection.41 Smears and cultures will help in the selection of specific topical and systemic antibiotics. Surgical therapy is typically necessary. Simple irrigation and probing of the canaliculus is usually ineffective. A small curette can be used to break up concretions and the typical sulfur granules, however, the curette should not be passed through the punctum as further scarring may ensue (Fig. 8C). A better approach is to dissect directly into the affected area of the canaliculus horizontally.42 The surgeon places a probe in the punctum and canaliculus and carefully cuts down onto the metal, allowing a careful curetting if stones are present (Fig. 9). The sinus of Maier at the internal common punctum also can be examined, lavaged, or curetted. A specimen should be sent for bacterial and fungal examiniation. Silastic tubing can be used as a stent after this type of procedure, and the canaliculus and overlying tissues should be closed with interrupted 7–0 absorbable sutures. Either a posterior approach or an anterior approach can be used, but the Silastic material should remain in place for at least 3 months if there is no significant irritation or recurrent infection.
Stones in the lacrimal sac usually are not of fungal etiology.43 Older women are affected more frequently than their male counterparts. The concretions frequently produce intermittent obstruction. Consequently, a good history is essential. A probing and irrigation may indicate patency, despite the presence of epiphora. Lacrimal sac stones can function like a ball valve and further confuse the clinical evaluation with the intermittent epiphora. DCG is one of the most helpful tools in diagnosing this problem. A DCR may be required before a cure can be achieved. In addition to stones, always consider the possibility of a foreign body such as a punctual plug blocking the system (Fig. 10A and 10B).
STENOSIS OF THE NASOLACRIMAL DUCT
Generalized or localized stenosis of the nasolacrimal duct can result from involutional changes or secondary to bouts of infection, stones, topical medications, or other sources of inflammation. DCR is the obvious cure for lower system block in the absence of any disturbances to the punctum, canaliculus, common internal punctum and sac. The role of Silastic intubation of the nasolacrimal duct for adult dacryostenosis is controversial. Although it may work in some patients with partial stenosis, it can produce dacryocystitis by causing complete obstruction to tear outflow. In contrast to children, the adult mucosal lining and surrounding bony duct are not in a dynamic state of growth. Therefore, the tubing can act as an irritant in a fixed system. More recently balloon dacryoplasty has been suggested as a treatment for partial obstruction of the nasolacrimal duct.44 DCR is still the preferred procedure for this type of problem.
LID MARGIN ABNORMALITIES
A variety of mechanical problems of the lid margin and its fascial supports can produce tearing.
Punctal eversion alone can occur (Fig. 11) and in milder forms may respond well to vertical cautery on the conjunctival side of the lid. An alternative is excision of an ellipse or diamond of the conjunctiva and tarsus. When the margins are brought together with several interrupted absorbable sutures, the everted punctum rotates into position. True medial canthal ectropion requires a more extensive repair, such as the lazy-T procedure advocated by Smith and Cherubuni.45 Another method is actual plication of the medial canthal tendon.46 Involutional ectropion involving the entire lid interferes with the lacrimal pump mechanism and can also stimulate reflex tearing through exposure. Standard ectropion repairs cure the epiphora problems in most instances. All of these lid procedures are well reviewed in other references.6,46–49
Flaccid Canaliculus Syndrome
The flaccid canaliculus syndrome was described by Jones and Wobig.43 Involutional changes may produce a nasolacrimal system that appears open to irrigation. However, lid laxity and poor lacrimal pump function contribute to poor tear drainage. Horizontal shortening of the lid may help, but frequently, a Jones tube combined with DCR is required. Again, caution must be exercised to ensure that the patient does not have an underlying dry-eye problem. If so, reflex tearing will continue and the patient may be unhappy.
Irritation from Lashes
Trichiasis and distichiasis are causes of reflex tearing, as previously discussed. These problems can be managed by cryosurgery, electrolysis, or a variety of lid margin procedures. Likewise, entropion can cause reflex tearing secondary to lash irritation. Rotation of the lid margin or other standard entropion procedures can eliminate these causes of epiphora.46–49
Trauma can occur at any site in the nasolacrimal drainage system. The form of trauma can range from chemical and thermal burns to avulsions and lacerations.
Whatever the source of energy causing a burn, the treatment is much the same to repair punctal or canalicular stenosis. Silastic stenting is required more frequently when the initial injury was thermal. The stenting also must be left in place for much longer than the usual period.
Lacerations of the punctum are rare, and those to the sac alone can be repaired primarily. The most common form of laceration to the nasolacrimal drainage system is the canalicular laceration. The guiding principle in the repair of the canaliculus is to reestablish the patency of the damaged system. The surgeon should minimize further trauma to the nasolacrimal system and be cognizant of the cosmetic details. Use of the pigtail probe in the repair must be used cautiously because it can too easily damage the sac and common internal punctum. The operating microscope assists in visualization of the lacerated ends and is highly recommended for surgical management. If the surgeon is more comfortable with high-power loupes, use of the operating microscope may be unnecessary. In fact, loupes may be more advantageous because the surgeon may have a greater field of vision and more mobility while repairing the laceration. The proximal or lateral end is located easily by passing a probe through the punctum (Fig. 12A and 12B). The medial or distal end usually can be identified easily with the use of the magnification. When both upper and lower canaliculi are cut near the sac, identification may be difficult. When a single canaliculus is cut, the use of a milky white steroid–antibiotic suspension injected through the intact canaliculus can assist in locating a cut end. Air can be injected in a similar fashion under a pool of saline, and the resultant bubbles can assist in localizing the distal end. The use of the operating microscope under high power has made these maneuvers unnecessary in most cases.
Surgical technique for the repair of lid lacerations has evolved to Silastic intubation of the nasolacrimal system.6 Either monocanalicular or bicanalicular stents can be inserted (Fig 13A, 13B, 13C, and 13D). The Silastic material moves easily and does not prohibit the lid from blinking normally. The flexibility of the tubing also allows for simpler anastomosis of the lacerated ends of the canaliculus. With Silastic intubation, 7–0 absorbable sutures can be placed submucosally (Fig. 14). The Silastic is placed into the nasolacrimal duct as described for pediatric dacryostenosis, and the canaliculus is repaired around the stent. If the laceration is in the medial canthal tendon area, repair of the deep and superficial heads of the pretarsal muscle should be done.6 The lid can further be supported by a mattress-type suture sling using a 4.0 vicryl on a P2 needle, transnasal wiring, or a supramid suture on a ski needle (Figs. 15 and 16). The orbicularis and skin are closed in layers with appropriate sutures. The Silastic tubing should be left in place for 4 to 6 months, if possible. Lack of epiphora is a positive sign indicating that the tears are passing despite the cicatrix from the laceration. The tears pass around the silastic tube into the nasolacrimal sac and exit from the duct. Unless chronic infection mandates removal, tubing should remain in place until symptoms or epiphora cease. A good rule of thumb is that the closer the laceration is to the punctum, the earlier the tube can be removed.
We recommend use of the Monaka or mini-Monaka system (FCI Ophthalmics, Marshall Hills, MA) for monocanalicular trauma. The mini-Monaka is an excellent choice for adults repaired under local anesthesia. This short stent has a built in punctal anchor and is more rigid than standard silicone tubing. The stent is first introduced into the lateral portion of the torn canaliculus and seated at the puncta. Once the lateral portion is appropriately placed, the remainder of the stent can be fed medially into the other portion of the canaliculus and down into the sac followed by suturing as above. For children, and those adults requiring sedation, the Monaka monocanalicular stent with a prolene feeder and a Ritleng probe can also be used. The advantage of this system is that traction can be applied to the tubing as it exits the nose thus rotating the lacerated eyelid into the appropriate anatomic position. There are several other methods of monocanalicular intubation mentioned for historic purposes only. A Veirs rod, which is a metal rod bonded onto a silk suture, may bridge the laceration and can be fixed to the lid with the suture.50 A Johnson wire can be placed into the canaliculus to provide a scaffold for repair. The wire can then be sutured onto the lid.51 Long52 devised a lacrimal stent from a silicone tubing attached to a punctal plug. The silicone tube bridges the laceration, which can then be fixed in place with the punctal plug. If both canaliculi are damaged, intubation of the entire lacrimal excretory system is advisable. Lacerations of both canaliculi at or near the common internal punctum are best managed with a DCR and retrograde probing with Silastic intubation, as previously described in the section on congenital abnormalities.
Major Midface Trauma
Fracture to the midface can shear the nasolacrimal duct. Surgical repairs in this region, especially when transnasal wiring is done, may damage the lacrimal sacs or ducts, causing nasolacrimal drainage obstruction. Lacrimal reconstruction in the absence of frank dacryocystitis should be delayed if possible until the major bone work in the orbital region is completed.53 Otherwise, good results may be undone, and subsequent repeat surgery often proves to be challenging. Less than optimal results may ensue (Fig. 17A and 17B and Fig. 18). As an aside, the best approach in these patients is to repair the nasolacrimal system in the acute setting at the same time the fractures are repaired. However, this is often not possible for logistical reasons. If at the time of the fracture repair the nasolacrimal duct is found to be severed, either stening the duct or a DCR should be done.
|The objective of lacrimal drainage surgery is to establish flow of tears
from the cul-de-sac to the nasal cavity. The techniques
used in children and adults are virtually the same. There are, however, some
specific differences that will be reviewed.|
SURGICAL MANAGEMENT OF LOWER SYSTEM BLOCKS
Pediatric Irrigation and Probing Under General Anesthesia
When pediatric general anesthesia is safely available and is selected by a surgeon, a face mask usually will suffice. However, a laryngeal mask is preferred because it is an excellent device that allows free access to the nose for retrieval of dye and irrigated fluids. Furthermore, it maintains the airway, even if it is necessary to perform Silastic intubation of the nasolacrimal system.54 An intravenous drip should be established before the surgeon performs the actual probing and irrigation. Endotracheal intubation should be done if there is any question about the child's airway. When the child is asleep, careful examination of the canaliculi should be done with gentle dilation of the punctum, as previously described, and careful passage of a lacrimal cannula (blunt 23-gauge cannula) attached to a 3-mL Luer-Lok syringe containing several milliliters of 2% fluorescein solution. The surgeon should feel for veils and strictures in each canaliculus and at the internal common punctum, before attempting to probe the nasolacrimal duct. The surgeon can attempt to use hydraulic pressure irrigation while occluding the opposite punctum as the initial effort to open the lower (distal) portion of the nasolacrimal system. If this maneuver fails, the lacrimal cannula can be used as a probe because it is between a number 0 and a number 00 Bowman probe in size (Fig. 19). After the cannula is shaped into a slight curve, this instrument can be passed gently into the nasolacrimal duct by the upper canaliculus. The lower canaliculus should be manipulated as little as possible. If any resistance is encountered because the cannula is too large, the surgeon should withdraw this instrument immediately and use a smaller Bowman probe. The probing instrument is slipped down into the nasolacrimal duct until it meets resistance at the lower end. The surgeon then should turn the curve of the cannula medially, and with a gentle but firm push, enter the inferior meatus. When the cannula is passed through the duct, any scraping sensation, rather than a smooth, sliding sensation, usually indicates a false passage or the presence of extensive scar tissue. In such instances, the instrument should be withdrawn, and the surgeon should make a gentle attempt to find the normal channel. If passage into the nose is not achieved because of a presumed false passage, it is preferable to stop the procedure and reschedule a probing and irrigation under a general anesthetic several weeks later to allow the operative inflammation to subside. The resolution of inflammation is aided by irrigation with 0.5 mL of an antibiotic steroid solution.
Location of the probe in the inferior meatus can be confirmed by metal-to-metal contact with a larger second probe placed through the nares. Direct visualization of the probe is particularly useful in complicated cases. This can be accomplished by using a head lamp, endoscope and nasal vasoconstrictor such as 4% cocaine solution or oxymetazoline (Afrin, Schering, Liberty Corners, NJ). In uncomplicated cases, a simple method of confirmation is to inject dye through the syringe of the cannula, using fluorescein on one side and methylene blue on the other side. The dye is collected from the inferior meatus of the nose with a soft, plastic suction catheter (number 10F Argyle oxygen catheter; Brunswick, St. Louis, MO) of pediatric size. The use of different dyes is convenient in confirming the patency of the system after irrigation and probing. Fluorescein dye should be used on any eye that has a high risk of needing Silastic intubation because methylene blue may stain the tubing. After these steps are completed, a careful intranasal examination should be performed. If the inferior turbinate seems to be impacted on the nasolacrimal duct opening at the initial examination, it can be pushed medially by infracturing the turbinate toward the septum with a Freer elevator or a Crawford hook (Fig. 20).43 After probing and irrigation, 1 mL of antibiotic steroid solution is irrigated through the upper canaliculus of each nasolacrimal system. The parents are instructed to use an antibiotic–steroid drop four times daily for the next week. The patient is seen in the office 2 to 3 weeks postoperatively. If one attempt at simple irrigation and probing for soft tissue obstruction of the duct is not successful, a repeat irrigation and probing is done. The secondary procedure may involve a Silastic intubation or balloon dacryoplasty. Also, the probing and irrigation procedure is combined with an inferior turbinate infracture if a distal obstruction is present at the valve of Hasner.
Timing of Irrigation and Probing for Congenital Dacryostenosis
The correct timing for initial probing of a child with nasolacrimal duct obstruction has been controversial.55–57 Based on a large study by Katowitz and Welsh,57 we recommend that initial probing be done when the patient is approximately 1 year of age. In this study of 572 eyes, the success rate with initial probing was 97% in patients younger than 13 months. In patients older than 13 months, however, the mean success rate was 54.7%. When subdivided into smaller age categories, a stepwise progression was observed from 76.4% for patients between 13 and 18 months to 33.4% for patients older than 24 months. In addition, the number and complexity of subsequent procedures appeared to correlate with the age of the initial probing. It is important to consider the actual gestational age of the child; a premature infant should be given a period of postnatal time to respond to conservative therapy that is equivalent to that for a full-term infant.
A major point of controversy regarding congenital dacryostenosis is whether to probe infants in the office or under a general anesthetic in a hospital setting.22,26,58,59 This controversy primarily applies to the initial probing procedure. All children who have had failed probings should have this procedure repeated under general anesthesia.
When deciding whether a general anesthetic should be used for the initial probing, the most obvious concern is the risk associated with general anesthesia. This risk is especially concerning in children less than 6 months of age. Fortunately, it is unnecessary to perform probings in children younger than 6 months for routine nasolacrimal duct obstruction. Parents should be full participants in any decision regarding the choice of office surgery or the use of a general anesthetic. With the increasing availability of good pediatric anesthesia staff, we typically recommend general anesthesia for initial probings.
It is difficult to attempt irrigation of the infant nasolacrimal system in the office. Probing of the duct alone, however, can be accomplished more easily.19,22,24,26 Some surgeons prefer the lower canaliculus for office probing, but as a general rule, it is best to avoid the risks of traumatizing this channel. A distinction should be made between therapeutic and diagnostic probing. An office probing in an infant is primarily therapeutic because there is little control over the child and, therefore, less time to feel for veils or strictures carefully at various points along the lacrimal drainage system. A diagnostic probing in an infant requires general anesthesia.
The technique of probing an infant's nasolacrimal system must be gentle because the infant's punctum is delicate. Wide dilators can be traumatic as the punctum can easily tear. The Jones punctal dilator (OP 7002, V. Mueller & Co., Chicago, IL) or a safety pin that will not dilate past a number 1 Bowman probe size should be used. Bowman probe sizes vary depending on the manufacturer, and therefore, the physician should be familiar with the actual width of the probe in use.22 In office probings, the child does not need to be mummified. The child's head can be held firmly against an assistant's knees, and the surgeon can sit at the child's feet, performing the probing from this position. Jones and Wobig19,43,60 prefer to use a number 0 or smaller probe in an infant and to leave the probe in place for 5 minutes after confirming its presence in the inferior meatus of the nose. They believe that this practice allows the mucosa to retract around the probe, and thus, facilitates a successful result.
We consider office probing in patients older than 3 months unnecessarily traumatic to the child, the parents, and the surgeon. With the availability of an excellent pediatric anesthesia department, probing under general anesthesia is preferred. General anesthesia allows the surgeon to perform a complete diagnostic and therapeutic probing as well as an examination of the nasal passage. Examination under anesthesia also provides the opportunity for retinoscopy and a dilated fundus examination. However, a number of respected surgeons prefer office probing in patients as old as 8 months.19,22,26,61
Adult Probing and Irrigation of the Nasolacrimal Duct
The adult patient in some ways is easier to treat than the pediatric patient. This is because of the physician's ability to perform a more thorough examination in the office and create an appropriate treatment plan. Proximal probing and irrigation of the canaliculus is a diagnostic procedure only and is done in the office with topical anesthetics as previously discussed. The canalicular probing will qualitatively and quantitatively define the point of pathology in the proximal or distal portion of the nasolacrimal system. Office probing of the full nasolacrimal system, even with topical anesthetic, is uncomfortable for the patient and therefore should not be performed. It is uncommon to perform a probing and irrigation of the nasolacrimal duct as an isolated therapeutic procedure. Rather, it is typically performed with balloon dacryoplasty or Silastic intubation in the adult population to treat partial nasolacrimal obstruction. Unfortunately, these two procedures are usally only temporizing because the stenosis recurs and these patient may eventually require DCR surgery. The exception to this rule is the patient with punctual stenosis. In these patients, probing and irrigation with Silastic intubation has a high success rate.
Silastic Intubation of the Nasolacrimal Duct
The major difficulty in dealing with persistent dacryocystostenosis is deciding how to proceed if all of these measures fail. Before progressing to the more aggressive DCR,22,62–67 a secondary procedure should be considered like passing Silastic tubing through the entire nasolacrimal system into the nose (Fig. 21). Although Silastic intubation of the nasolacrimal system appears to be a more conservative and reasonable approach, it can be a traumatic procedure, especially in a young child. Therefore, caution is essential to minimize complications. Furthermore, the procedure is not indicated for bony obstruction or severe scarring from previous procedures. In addition to Silastic intubation, balloon dacryoplasty of the nasolacrimal duct is a viable secondary option.
For many years, bicanalicular Silastic intubation has been the gold standard for secondary treatment of failed probings.68 Silastic tubing comes packaged in several ways. The important features to consider in choosing a packaged set for nasolacrimal intubation are that the metal probe be malleable enough to minimize the trauma to the nasolacrimal system and that the tubing be bonded sufficiently to the probes to avoid slipping during passage through the system. Free tubing can be loaded onto a Quickert probe and passed. Tubing (Silastic, Dow Corning, New York, NY; tubing 5941, Storz, St. Louis, MO) of 0.025 mm external diameter is preferred for pediatric and adult use. The tubing can be glued in place with silicone bonding glue. It is stretched over a number 0 tapered probe (Quickert 4220, Storz) before autoclaving. Packaged intubation sets like Crawford Silastic set (28–0185; hook, 28–0186, Jedmed Instrument Co., St. Louis, MO), O'Donoghue lacrimal tubes (Visitec, Sarsota, FL), and Guibor lacrimal tubing also are available. They are more expensive, but avoid the need to prepare the probes with tubing.
In 1988, monocanalicular intubation sets became available (Monaka tubes). Fayet and co-workers69 developed and studied the success rate of monocanalicular stenting. His group showed a similar success rate between bicanalicular stenting and monocanalicular stenting. Kaufman and co-workers70 had a 79% overall success with monocanalicular stenting. At Children's Hospital of Philadelphia, we had a 91% success rate in our first 35 cases71 and then proceeded to coleect a prospective series of 101 patients which indicated a 93% success rate.72 The use of monocanalicular stenting has become our preferred method of placing Silastic tubing during a probing and irrigation. It effectively stents the system like bicanalicular stents but has two major advantages. First, monocanalicular stents self anchor in the puncta, thus only one canaliculus is subjected to probing and potential injury. Second, these stents can easily be removed in the office without the need for a general anesthetic.
TECHNIQUES OF INSERTION.
Passage and retrieval of the probes may be difficult. It is important to recognize that intubation of the nasolacrimal system requires the physician to negotiate several right-angle turns, particularly when entering through the lower canaliculus. Furthermore, as the probe emerges near the floor of the nose, it can be difficult to withdraw, especially in the young child. This problem occurs because the inferior meatus in a child is flat, and there is little space between the floor of the nose, the lateral nasal wall, and the inferior turbinate (Fig. 22).73 Silastic intubation of the nasolacrimal duct can be particularly traumatic if the probes are not malleable (Fig. 23). By the age of 3 years, more space has developed, but it is still less than half of that present in the adult. For this reason, it can be difficult to reach in and withdraw the probe with Silastic tubing from the inferior of the nose without causing trauma to the nasolacrimal duct in the interior of the nose. Enlarging this space by using a nasal vasoconstrictor (4% cocaine or oxymetazoline) and infracturing the turbinate toward the nasal septum, as previously described facilitates visualization and removal of the probe.
Many methods have been devised in an attempt to improve the original grooved director retrieval method of Quickert and Dryden.63 A straight hemostat often can be used successfully in a larger child, particularly when the turbinate is infractured. However, the malleable Crawford-type probes offer an advantage in that they can be retrieved, even in a small infant, by using the corresponding hook Fig. 24).64,74 It is important to recall the intranasal anatomy while retrieving the malleable probe. The nasal floor, which is also the palate, is the inferior limit of the inferior meatus. The inferior turbinate arises from the lateral nasal wall. Thus, by staying parallel to the palate and directing the hook laterally towards the ear, the inferior meatus is easily located. After entering the inferior meatus, tactile movement is required to locate and retrieve the Crawford probe. Detachment of the Silastic from the probe may occur when the probe is retrieved from the inferior meatus of the nose and the junction of the tubing and the probe is pulled through the punctum into the nasolacrimal system. Usually, dilation of the punctum before insertion of the probe and application of an ointment for lubrication at the junction of the metal and Silastic will prevent this detachment.
As for the monocanalicular stents, our preference is to use the Ritleng probe for passage. This hollow probe has a directed groove at the distal tip (Fig. 25A and 25B). The prolene portion on the Silastic tubing is fed down the probe and recovered from the nose (Fig. 26). Sometimes the directional groove will lead the prolene portion directly out the nostril. It is helpful to feed a majority of the prolene down the probe to facilitate distal recovery. The Ritleng hook, Crawford hook, or myringotomy forceps can be utilized to retrieve the prolene portion from the nose. If any trouble is encountered retrieving the prolene feeder, the surgeon should feel for the Ritleng probe and hook it. Once the hook is around the probe, the probe should be rotated 180 degrees because this will position the distal opening of the probe posteriorly. In addition, the probe should be slightly withdrawn. The hook will engage the prolene feeder when the hook is pulled anteriorly. It is important to note that the prolene thread has two portions, a light blue section and a dark blue section. The darker portion has a thicker diameter. When all the dark prolene has been inserted down the probe, the light blue, thinner portion should be passed outside the slit on the side of the probe. Simultaneously, the probe should be removed proximally from the nasolacrimal system.
FIXATION OF TUBING.
Monocanalicular stents are easy to fix in place. Once placed, the tubing has a collarette with a punctal anchor on the proximal end that nicely seats itself in the puncta similar to a punctal plug. The collarette has two components: a flat surface that lies on the lid margin, and a small bump under the plate, that anchors into the puncta (Fig. 27A and 27B). The colarette comes in two sizes, 3 mm and 4 mm. We prefer the smaller 3-mm–sized stents for use in infants and toddlers.72 For adolescents and adults, we recommend using the 4-mm–sized tubes. The stent is placed over a Ritleng probe as previously described. Of note, the difficulty with these tubes is not fixation but rather the passage through the nasolacrimal system. Once the stent is in place, a small punctal plug seating device is inserted into a small hole in the anchoring plate. The surgeon can facilitate seating the stent by simultaneously pulling the distal prolene potion and pushing the anchor with the seating device. A small pop is felt when then anchor locks into the punctum. If the punctal plug seating device is not available, a number 0000 Bowman probe or a fine tip punctal dilator can be used instead.
One caution is not to overdilate the punctum prior to placement. An enlarged punctum may not hold the anchoring device in place. Also, it is advisable not to use the monocanalicular stent with a punctoplasty because the anchoring device will not anchor and may retract into the canaliculus. The monocanalicular stent may be placed through either the upper or lower puncta. Our preference is to utilize the upper puncta in routine cases of nasolacrimal duct obstruction. Finally, when trimming the tubing, it is important to leave the tubing long enough such that the Silastic does not retract proximal to the valve of Hasner because this would defeat the purpose of stenting the nasolacrimal duct.
Fixation of the bicanalicular Silastic tubing has been controversial.75 The use of multiple square knots alone for fixation in the pediatric age group allows a potential problem to develop if the child grasps the loop in the medial canthus and pulls the tubing and knots into the nasolacrimal duct and sac (Fig. 28). This problem will be seen as a long loop of the tubing visible at the medial canthus and extending toward the cornea or actually lying on the cornea. This complication can be remedied by cutting the tubing and pulling the knots through the common internal punctum and upper canaliculus, but only if a simple square knot or two have been tied so that the knot is not large enough to damage the canaliculus. If general anesthesia is utilized, then our preferred method is to cut the loop at the medial canthal angle and wedge a small probe into the lumen of the Silastic tubing (Fig. 29) that emerges from the upper punctum. This probe, attached to the tubing (in effect, a reversal of the Crawford tubing system), can be passed down through the lacrimal drainage system and identified in the inferior meatus. The tubing can be extracted from the nostril, and if necessary, the system can be reintubated.76 In an adult, the loose tubing usually can be visualized in the nares with a head light and nasal speculum. Alternatively, an in office endoscope may be utilized for visualization. The ends of the tubing can be pulled out of the nostril with forceps, and a small silk suture can be tied over a piece of scleral buckle sponge around the tube ends proximal to the original knot, thereby shortening the loop and preventing the knot from escaping up the nasolacrimal duct (Figs. 30 and 31).
For bicanalicular stent fixation, in order to prevent these complications, we prefer to pass each probe through a small piece of scleral buckle sponge and then to tie square knots to secure the stent in the appropriate position.75 The size of the loop is an important factor. It is important to allow for 2 to 3 mm of lateral motion of the loop at the medial canthus when it is pulled with a muscle hook after the sponge is positioned properly underneath the inferior turbinate posteriorly. After the probes are slipped through the sponge, they are removed, and multiple surgical knots are tied so that the sponge cannot slip off of the ends of the Silastic tubing. The ends should be cut so that they are not visible externally. An alternative method is to secure the loop of Silastic inside the nares with a 5–0 prolene suture again with the appropriate amount of tension on the Silastic.
The postoperative management after Silastic intubation of the nasolacrimal duct requires regular follow-up. There is little maintenance required in these patients, but they should be monitored for potential problems. With the use of monocanalicular stents, there is minimal concern. The two problems in our experience with the monocanalicular system are spontaneous extrusion in approximately 10% of patients and corneal/conjuctival abrasions in less than 5%. In patients with bicanalicular stents, they should be watched for cheesewiring, or the slitting of the canaliculi and puncta (Fig. 32). This condition can occur if the loop is tied too tightly and is also because of the rapid growth of young children. The loop has a fixed length, so slitting of the canaliculi may occur as the face enlarges. A slit of up to one half of the canalicular length does not seem to cause any problems in the otherwise normal canaliculus, but nevertheless, it is a complication that should be avoided if possible. The loop should be tied loosely enough to allow for some growth, but not too loosely such that the cornea could be irritated on adduction of the globe. Another complication of Silastic intubation is the formation of a granuloma of the punctum or canaliculus (Fig. 33). This problem can be corrected by simple excision of the granuloma and cautery of the base.
Silastic intubation of the nasolacrimal system is done as an outpatient day-surgery procedure. Patients or their parents should be cautioned about postoperative bleeding from the nose. Frank hemorrhage is uncommon but serious in a young child because of a relatively small total blood volume. Afrin nasal spray, cold compresses, elevation of the head in bed, and nasal packing can be used if necessary. If the hemorrhage persists, thrombin in gelfoam or bipolar cautery may be required. Hospitalization and possible assistance from an otorhinolaryngologist may also be necessary. Fortunately, significant hemorrhage is a rare complication. After Silastic intubation, the patient is routinely given an antibiotic ointment such as polysporin or a combination antibiotic–steroid eye drop to be used two to four times daily. Patients should be seen several weeks postoperatively if there are no unusual problems. Continued follow-up every 2 to 3 months is required while the tubing is in place.
REMOVAL OF TUBING.
The time of tubing removal has increased from the original 6-week concept to 6 months for children younger than 2 years, and up to 1 year for older children.63,64,66 This timing allows the duct and its mucosal lining to respond to the stent. This concept of a response is important; especially in a young child, rapid growth is occurring, and in the same way that it is possible to expand a microphthalmic orbit with tiny lid fissures with the use of increasingly larger conformers, it is possible to expand the nasolacrimal duct with the Silastic stent during the growth period.
Removal of the monocanalicular stent is done in the office. Adult patients will easily tolerate the removal, which is like placing a punctal plug. Children can also tolerate the removal with the parent's assistance. The child is held on the parent's lap and topical anesthetic is placed in the cul-de-sac. Then with the parent holding the child still, a Castroviejo needle holder is used to grab the flat plate portion of the stent (anchor) out of the punctum. If done quickly, the stent removal can be atraumatic. Removal of the bicanalicular tubing usually requires general anesthesia by face mask or laryngeal mask in children. Occasionally, in a very cooperative child, removal can be done as an office procedure that is similar to removal of tubing in the adult. Visualization of the inferior meatus through a nasal speculum is aided by the use of 4% cocaine or Afrin spray to shrink the nasal mucosa. Blowing the nose in the office and suctioning in the operating room also may be helpful in placing the tubing in an anterior location for removal. The loop is cut with a scissors in the medial canthal area after a topical anesthetic is instilled. The ends of the Silastic tubing are grasped with a hemostat or small needle holder and pulled from the inferior meatus. A fiber-optic head lamp or indirect ophthalmoscope is useful. The major advantage of the monocanalicular tube system over the bicanalicular systems is the ease of tubing removal in the office.
Balloon dacryoplasty was initially developed from angioplasty technology.77 Subsequently, a lacrimal catheter was introduced to the market and its efficacy has been proven by several groups in both children and adults.71,78,79 This technique utilizes a 2- or 3-mm diameter balloon inflated to 8 atmospheres of pressure to dilate strictures or partial obstructions in the nasolacrimal duct (Fig. 34). Balloon dacryoplasty is typically reserved for nasolacrimal obstruction refractory to probing. Although some surgeons utilize this procedure on as a primary probing technique in children, we typically reserve it for patients who have persistent nasolacrimal duct obstruction after primary probing and irrigation.
Balloon dacryoplasty is performed just like a probing. A 2-mm balloon is chosen for children under age 39 months and the 3-mm balloon is used in those individual that are older. Both balloons have two marks proximal to the balloon, one 5 mm proximal to the balloon and the second 15 mm proximal. The procedure can be performed via the upper or lower canaliculus. The punctum is dilated and the catheter is inserted into the lacrimal system. Topical antibiotic ointment can be applied to the end of the balloon to facilitate passage. The catheter is fed down through the valve of Hasner similarly to passage of a Bowman probe (Fig. 35). When the balloon is appropriately positioned, the mark 15 mm proximal to the balloon is at or just inside the punctum. The balloon is then inflated with a hand pump to 8 atmospheres of pressure for 90 seconds, deflated, and then reinflated for 60 seconds. The balloon is then deflated and the catheter is withdrawn 10 mm from the nasolacrimal system using the 5 and 15 mm marks as a guide. The double-inflation cycle is then repeated and the catheter is removed from the system. Care should be taken when performing the second round of dilation in the proximal portion of the nasolacrimal duct and sac not to accidentally bring the end of the balloon through the common canaliculus. Inflation in this area could damage the common canaliculus.
The postoperative care after balloon dilatation is the same as after probing and irrigation. A topical antibiotic–steroid ophthalmic solution is used four times daily for 1 week.
If the more conservative procedures described above are unsuccessful, or if there is obvious bony obstruction below the lacrimal sac, a DCR must be performed.62 Local anesthesia can be used in adults by blocking the infratrochlear nerve, which can be accomplished by injecting several milliliters of a local anesthetic mixed with epinephrine in a ratio of 1:100,000. The effects can be enhanced by controlled sedation, which is of particular value in the elderly patient. Controlled hypotension is beneficial as well. The middle meatus should be packed with quarter-inch gauze tape or one-half × 3 inch patties soaked with oxymetazoline or 4% cocaine. This treatment will shrink the nasal mucosa and reduce hemorrhage as well. A reverse Trendelenberg position with the table tilted to 30 degrees (head up and feet down) and injection of a local vasoconstrictive agent are useful adjuncts for controlling bleeding. Positive pressure applied to the respiratory bag during general anesthesia also will reduce venous flow in the operative area. Controlled hypotension anesthesia provides the best hemostasis. Some surgeons use a small amount of diluted methylene blue instilled in the lacrimal sac through the punctum and canaliculus. This stain will outline the sac mucosa. However, if not sufficiently diluted, the stain can leak from the sac when cut, and cause confusion in differentiating anatomic layers (see Fig. 5).
Usually, a straight vertical incision is made through the skin only over the nasal bridge, approximately 10 mm medial to the canthal angle. Caution is exercised to avoid the angular vessels that are located approximately 8 mm medial to the medial canthus. A medial lower lid crease incision or an extended subciliary blepharoplasty incision can be utilized if there are any cosmetic concerns. The vertical incision is preferable as it facilitates excellent visualization of the common internal punctum when the lacrimal sac is opened. Using the standard approach on the nasal bridge, the superior end of the incision should be placed just below the level of the medial canthal tendon. A straight incision on the nose reduces the chances of a postoperative bowstring scar, although several variations and modifications of this incision have been designed to eliminate this concern.80 With a number 15 Bard-Parker scalpel blade, the orbicularis muscle is then carefully incised down to the periosteum (Fig. 36). The angular vessels are retracted laterally with the orbicularis muscle by small rake retractors or a self-retaining retractor. If these vessels are cut, they should be cauterized or ligated to ensure visualization of the surgical field. The periosteum is incised with a scalpel blade and reflected laterally with a sharp periosteal elevator to the anterior lacrimal crest. The medial canthal tendon can be disinserted with the periosteum if wider exposure is needed later. Caution is required as the periosteum is lifted over the anterior lacrimal crest, where it is very adherent, so that the elevator does not tear through and enter the lacrimal sac. In the child, this crest is flat and the lacrimal fossa very shallow. Once over the periosteal attachment, at the crest, the lacrimal fossa is easily stripped free of periosteum. The periosteum is then retracted laterally to visualize the medial lacrimal sac wall.
A hand trephine of 10 mm diameter (Arruga, Dixey Co., London, England) can be used to drill down to the nasal mucosa (Fig. 37). There are two trephines, one with a sharp central point and coarser teeth to engage the bone and create the initial cut (Fig. 38), and a finer toothed trephine that can be worked more gently down to the level of nasal mucosa. The surgeon cuts down perpendicularly to a sufficient depth and uses a sense of feel to rock the hand trephine back and forth, thereby fracturing the bone. The circle of bone can be removed with an Adson or other heavy forceps. It is peeled off of the nasal mucosa gently, with the use of a Freer periosteal elevator. A Stryker saw attachment, curved hemostat, Hall air drill, or mallet and osteotome are alternatives for gaining entrance through the bone to the nasal mucosa. The advantage of the hand trephine over the other methods is a controlled entrance to the nasal mucosa, which produces less chance of mucosal disruption and allows a sufficient opening for the use of bone punches.
The periosteum anterior to the bony opening should be elevated from bone with a periosteal elevator for 2 to 3 mm to allow later suturing of the lateral edge of the periosteum with the medial canthal tendon back to its normal anatomic position. The nasal packing is removed to relax the mucosa, and the bony opening extended to about 15 mm in diameter, approximately thumbnail size (Fig. 39). The lacrimal sac is identified beneath the periosteal layer, which has been reflected laterally, by placing a blunt right-angle probe (Werb, Dixey Co., London, England)) or Bowman probe into one canaliculus to point up under the periosteum. The sac can be entered with a scalpel blade, by cutting directly over the probe, or preferably by cutting the sac with right-angle scissors (Werb). Cutting also can be done at the entrance of the sac to the nasolacrimal duct (Fig. 40). This step is facilitated by prior removal of the medial wall of the nasolacrimal duct.
One blade of the scissors is passed into the opening created at the top of the duct, and the sac is divided from an inferior to a superior direction. The most important flaps are the anterior flaps from the sac and the nasal mucosa because the posterior flaps will fall together. The only concern with large posterior flaps is the creation of a posterior sac or nasal flap that is too large and might move out of position postoperatively occluding the common internal punctum where the canaliculi enter the sac. This problem is avoided with the use of short posterior flaps. Before incising the nasal mucosa, the surgeon removes the nasal packing and passes a small curved hemostat up to the nose to indent the mucosa and confirm that the space to be entered is actually in the nose and not in an anteriorly placed ethmoidal air cell.
Nasal mucosal flaps are fashioned after incision of the mucosa from the inferior to the superior end of the bony opening. The width of the anterior flap is important; there must be an adequate flap to suture to the anterior flap of the lacrimal sac if this type of technique is used. The posterior flaps can be closed with interrupted 4–0 or 5–0 absorbable sutures on a semicircle needle, or they can be cauterized together.81,82 Closure of the posterior flaps usually is not necessary if the flaps are short and lie in near apposition. In this position, the flaps will not be able to occlude the internal common punctum postoperatively.
An alternative method recommended by McCord6 is to create a large posterior flap of nasal mucosa by incising the nasal mucosa high and folding it down to meet a short posterior flap of lacrimal sac. The anterior flap is formed entirely of lacrimal sac. The incision into the lacrimal sac is made very posterior so that a large anterior mucosal flap is created; the flap can be sutured to the remaining anterior nasal mucosa or to periosteum at the end of the bony opening (Fig. 41). This method also is useful if the nasal mucosal flap has been damaged or inadvertently cut near the top of the bony ostium. The DCR also has been described without forming any flaps but we do not recommend this for the external approach.83
The common internal punctum should be examined carefully by passing blunt probes through this structure through each canaliculus (Fig. 42). Most patients have a true shared internal entrance of the canaliculi, but occasionally, there may be separate, but normal, internal puncta.43 Any scars or obstructions of this area must be excised with scissors, and a new common opening created by intubating the canaliculi with Silastic material (Fig. 43).
If Silastic intubation is not done as part of the DCR procedure, separation of the mucosal flaps must be maintained by some other means for some time during the postoperative period. The posterior flaps can be held in place and separated from the anterior flaps by the placement of a large catheter through the DCR ostium and into the nose.62 Silastic is superior to rubber for this purpose because it cannot shed pieces that might potentially be aspirated. The wider end of the catheter is held in position, separating the nasal and lacrimal sac mucosal flaps, by a single 4–0 absorbable suture placed superiorly in soft tissue. The lower end of the catheter can be cut short at the external nares. This catheter should be removed 5 to 7 days postoperatively by placing one blade of a hemostat into the lower opening, clamping it, and twisting it clockwise until the suture holding the superior end pulls free and the catheter can be removed easily. Another method of separating the flaps is to pack the sac and nose with one-quarter- or one-half–inch gauze. Plain Vaseline gauze (Chesebrough-Ponds, Greenwich, CT) can be used and is preferable to iodoform types, which may be irritating. This type of packing can be removed 5 to 7 days postoperatively. However, the packing material may be sutured inadvertently during the anterior flap closure. The packing can adhere to the nasal mucosa and cause bleeding on removal. The packing could also act as a potential source of infection or even produce a toxic-shock–type syndrome. If Silastic intubation is not performed with the DCR, we prefer to use a rubber catheter, or if there is concern for postoperative hemorrhage, a Gelfoam (Upjohn, Kalamazoo, MI) thrombin stent placed between the flaps.79
SILASTIC INTUBATION COMBINED WITH DACRYOCYSTORHINOSTOMY
Silastic intubation is recommended as a standard portion of DCR surgery. Silastic tubing bonded to a probe is passed through each punctum and canaliculus to emerge from the internal common punctum (Fig. 44). The Guibor tubing system is useful. Either a groove director or a hemostat can be used to pull the probes through the opened lacrimal sac and out the external wound. After the two ends of the Silastic stent is recovered from the wound, each end is passed through a 1-cm length of Silastic tubing of slightly larger internal diameter, pulling the thinner Silastic tubing through. The metal probes are pulled free from the ends of the tubing. A triple tie is placed in the ends of the Silastic tubing and pulled tightly enough to estimate the appropriate tension of the loop of the medial canthal area. The Silastic cuff and tubing should be placed through the bony ostium before completion of the surgical knots, and the ends are pulled out of the nose to estimate this tension properly. The cuff also functions in stenting the system. A small curved hemostat passed up the nose from the external nares is useful for grasping the ends of the Silastic tubing to pull them inferiorly. It is useful to place the ends of the tubing in a needle holder and pass them into the open clamps of the hemostat. As was previously described for Silastic intubation in dacryostenosis, approximately 2 to 3 mm of lateral movement in the tube should be permitted. This movement can be estimated by pulling the loop with a muscle hook at the medial canthus.
Once the appropriate tension is achieved, multiple surgical knots that are large enough to prevent inferior displacement and loss of the Silastic cuff should be tied. The Silastic tubing is then stretched from the nose under moderate tension and cut so that the ends remain long enough to avoid untying, but short enough that when cut, they will retract high enough to be invisible externally. Aside from a slight sense of nasal stuffiness, the presence of the tubing presents no postoperative problem to normal nasal breathing. The anterior flaps of the lacrimal sac and nasal mucosa are joined with interrupted 4–0 or 5–0 absorbable sutures (Fig. 45). We prefer to use 4–0 Vicryl suture on a small half circle (Ethicon P2 cutting needle, J503, Ethicon, Inc., Somerville, NJ) needle. If the nasal mucosa has been damaged and is insufficient for closure, a larger anterior flap of the lacrimal sac should be fashioned and the mucosa sutured directly to the periosteum at the medial edge of the bony ostium (see Fig. 41B). If the anterior flap of nasal mucosa is too large and there is risk of it causing obstruction, it should be trimmed conservatively. The lateral periosteum, which may include the medial canthal tendon if a wider dissection was done, is rejoined to the medial edge of the periosteum with interrupted 4–0 absorbable sutures. The muscle and subcutaneous tissues are closed with interrupted 6–0 absorbable sutures. The skin is typically closed with a running subcuticular 5–0 nylon suture (Fig. 46). Fixation of the suture can be accomplished by tying a loop at each end. This method is particularly useful in children. This suture should not be pulled too tightly, however, because the knots can migrate subcutaneously during the postoperative period. An alternative is to apply tincture of benzoin to the wound and a steri-strip over the shortened sutured ends. With either method, a mild pressure dressing should be applied for 12 to 24 hours.
Unless there are extenuating circumstances, DCRs are usually done as an outpatient surgical procedure. If Silastic tubing has been used as a stent, the postoperative course is more pleasant. There is minimal edema with the DCR technique described above, regardless of the stent used. The small pressure dressing usually is left in place only until the next morning. In a pediatric patient, the dressing can be removed as soon as the child awakens from anesthesia. Antibiotic ointment or drops usually are applied to the conjunctival cul-de-sac at bedtime only during the first week postoperatively. Patients with nasal packing or a fixed catheter, which applies to those patients without a stent, need to have the packing or catheter removed 5 to 7 days after surgery. Again, the use of these materials can increase the risk of infection or result in bleeding when removed. Thus it is less common for these to be currently used and are discussed only for completeness. Finally, appropriate systemic antibiotic, such as a first-generation cephalosporin can be given intravenously during the procedure and continued orally for 3 to 5 days postoperatively. However, some believe that one or the other is adequate and that both intraoperative antibiotics and postoperative antibiotics are not necessary.84–87
The Silastic tubing can be left in place for long periods in the adult as it is so well tolerated. The stent is typically removed 6 to 12 weeks postoperatively if there are no associated canalicular or common internal punctal problems noted at the time of surgery. The nylon subcuticular suture can be removed 5 to 7 days postoperatively. Although granulomas at the ostium have been noted after DCR with Silastic tubes, many patients who are free of symptoms are reluctant to have the tubing removed. We have seen adult patients retain Silastic tubing without any problems for as long as 10 years.
Endoscopic DCR has become popular over the last decade because minimally invasive surgical techniques have come into vogue. As early as 1893, the internal approach to DCR was described,88 and subsequently it was developed to approach success rates similar to those for the external approach to DCR. However, the internal approach was not commonly in use until the development of the endonasal laser DCR in 1990,89 utilizing an internal DCR technique with the use of fiber-optic and laser technology. An argon blue–green laser is coupled to a fiberoptic laser catheter and used endoscopically to remove nasal mucosa and bone. The reported advantages of endoscopic laser surgery include decreased tissue damage, absence of cutaneous scar, excellent hemostasis, and decreased perioperative morbidity.
More recently, endoscopic DCR utilizing functional endoscopic sinus equipment has increased the popularity and success rate of the endoscpopic approach. A variety of techniques are described in the literature.90–96 These range from endonasal drilling and trephination, to the use of a ronguer and/or adjunctive use of mitomycin C. One approach is the following: the nasal mucosa is anesthetized with 4% cocaine and local 1% lidocaine with epinephrine injection into the nasal mucosa just anterior to the middle turbinate. The mucosa in this area is incised with a sickle knife and removed with front biting cutting endoscopic instruments. Once the bone is exposed, a burr is used to remove the wall separating the nasal cavity form the lacrimal sac. With the sac exposed it is incised vertically and exposed. The system is then stented with bicanalicular Silastic stents and secured in place (Fig 47A, 47B, and 47C). This technique is efficient with minimal morbidity and no external scar. However, because the lacrimal sac is not sewn to the nasal mucosa, the ultimate size of the fistula reduces to that of the Silastic tubing diameter. Some individuals have tried treating the fistula site with topical mitomycin C to prevent the fistula opening from shrinking with varied results. Overall, in experienced hands the endoscopic approaches are efficient and effective with success rates well in the 90% range similar to external DCR.
Attempts to streamline the technique have included utilizing a vitrectomy fiber-optic light pipe to assist with surgery. The light pipe is fed into the canaliculus and into the lacrimal sac. The light then visualizes where a small mucosal incision is made and the bone can be removed under direct visualization with ronguers followed by stenting. 97 The most recent technique described by Dolman87 involves placing a large Bowman probe into the lacrimal sac and simply puncturing through into the nasal cavity. After the probe is identified in the nasal cavity, the opening is expanded under direct visualization with a ronguer and stented. This proves to be quick, efficient, and as effective as standard DCR surgery.
Finally, a new large 9-mm balloon catheter was recently introduced as an additional alternative. In this instance multiple passes are made with a large Bowman probe to create a Swiss cheese-like pattern in the bone between the lacrimal sac and the nasal cavity. The balloon is fed into the lacrimal sac in retrograde fashion, straddling the bone and inflated. The authord have no experience with this technique.
With these advantages, many still consider the external approach the gold standard. The success of the traditional external approach and its low morbidity are well documented. Yet with the improved technology of the last 10 years along with exposure to endonasal surgery and experience, the endoscopic approach is a viable alternative, especially to the patient who does not wish to have an external scar. In fact, in experienced hands, the endoscopic success rates are approaching that of the traditional approach.
Previously, many methods to revise a failed DCR have been described.62–64,98–100 These include dilation with a lacrimal probe, intranasal dilation with a muscle hook, and enlarging the passageway with a knife, trephine or laser. Intranasal rongeuring, directly or endoscopically, of obstructive tissue has also been described. In 1989, Becker and Berry101 described dilation with a balloon catheter for revision of failed DCR (Fig. 48). Although balloon dacryoplasty is useful in congenital nasolacrimal duct obstruction, we have had limited success with the procedure in adult DCR revisions.
The endoscopic approach is useful in patients who need revision of DCR. The nasal ostium is easily identified and work is accomplished in a retrograde fashion. The ostium can easily be expanded with functional endoscopic sinus surgery instruments or a rongeur. Debris obstructing the fistula can also be identified and removed (Fig. 49).
ABNORMALITIES OF THE PUNCTA AND CANALICULI (UPPER SYSTEM BLOCKS)
Surgery of the punctum should be as conservative as possible. For simple congenital veils, gentle puncture followed by dilation and irrigation often will suffice. For greater degrees of atresia, however, injection of methylene blue into the lacrimal sac through the skin may be of value, particularly when the surgeon suspects that the canaliculus may be involved (Figs. 50 and 51). The surgeon can apply pressure over the lacrimal sac area and look for retrograde flow of dye through the lid margin. If the dye is not visible, an incision in the lid margin can be made in the area of the lacrimal papilla, if present. If the punctum is not present, an incision can be made approximately 8 mm lateral to the medial canthal angle (Fig. 52). If dye is visible, the channel is normal (Fig. 53). If suction of the nose reveals dye, the sac and duct are clearly patent, and a stent of Silastic tubing can be placed throughout the nasolacrimal system, as is done for dacryostenosis (Fig. 54). However, if there is obstruction in the lower system, a DCR will be necessary. Silastic tubing can be run through the entire upper and lower canaliculus and through a DCR opening.
Punctal stenosis in the adult population is a common cause of epiphora as previously discussed. Again, before proceeding with surgery, the surgeon should be especially cautious of the older patient with a concominant dry eye as increased tear outflow may further exacerbate the reflex tearing. Several techniques are available to treat punctal stenosis. The two recommended techniques are a punctoplasty and Silastic stenting. The punctoplasty allows for controlled opening of the punctum. Typically a two-snip procedure is performed. This is performed in one of two ways. The first is to remove a V-shaped wedge from the vertical portion of the puncta and canaliculus on the conjunctival surface. This opens the most proximal portion of the system with out risking damage or scarring to the remainder of the canaliculus. The second two-snip procedure consists of a single vertical cut that is created in the puncta and canaliculus followed by a single horizontal cut along the proximal portion of the canaliculus. The concern with these techniques is the potential damage to the canaliculus and its function. If too much is cut, the canaliculus may not function properly. Also there is a greater chance for scarring within the canaliculus as it heals. To counterbalance the potential for scarring after the snip procedure, a Silastic stent can be placed. The stent may also serve the function of dilating and holding open the puncta and canaliculus as the system heals. Overall punctoplasty and stenting can be quite helpful. If the patient does not respond, however, consideration should be given to some of the other functional problems such as the flaccid canalicular syndrome. It may be useful to obtain dacryoscintigraphy in evaluating the tear outflow function of the problem patient.
For more extensive blocks in the canalicular system, a bypass procedure is usually required. Until recently, the use of a bypass tube, such as the Jones Pyrex tube (Gunther Weiss, Beaverton, OR), was considered impractical for the pediatric age group. Greater experience, as well as the use of a suture to hold the tube in place, has made this approach more practical for pediatric patients with canalicular atresia or severe obstruction.102 The Cox Pyrex glass tube set (Cox Ocular Prosthetics, Birmingham, AL) is also useful because of the suture eye in its collar, which enables fixation to adjacent tissue. Furthermore, the Cox set includes a trocar for insertion and a measuring device to determine the tube lengths (Cox tubes).103
Although a DCR with Silastic intubation is preferable to Pyrex bypass tubes, this has limited success in patients with more extensive blockage of the canalicular passages, despite earlier optimistic reports.104 An alternative to the bypass approach is a microsurgical anastomosis of the involved canaliculus directly to the nasolacrimal sac.105 Such techniques, although promising, are technically difficult and cannot correct extensive blocks in the canalicular system. Therefore, the bypass procedure remains one of the most important procedures for controlling canalicular causes of epiphora.
The Jones Pyrex tube is useful because of its excellent capillarity. The tube is available in a variety of lengths and angles. Tubes can be manufactured with a suture eye in the collar of the tube. This type of tube is particularly useful for the pediatric age group as the postoperative period is more difficult in children. If the tube is not held securely with a nonabsorbable suture, sneezing or blowing the nose can cause loss of the tube. Even without an eye in the collar, the tube can be secured by tying a suture around the cuff to the adjacent tissue for stability. Most recently Porex (Fairburn, GA) introduced a Pyrex tube with a porous polyethylene coating that allows the tube to be fibrovascularly integrated into the soft tissue as another means of securing the tube. Several other materials, including Silastic and polytetrafluoroethylene have been suggested for bypass tubes.106,107
The Silastic tubes often require cutting the collar to fit, which could produce rough and potentially irritating edges. None of the alternative materials, including venous or mucous membrane grafts, have the excellent capillarity of Pyrex. Therefore, use of alternate materials is less successful as the tear flow is reduced. In addition, synthetic materials allow more rapid accumulation of protein deposits postoperatively.
The bypass technique was well described by Jones108,109 as a conjunctivodacryocystorhinostomy. This technique is required not only for true congenital atresia of the canaliculi but also for obstructions larger than 2 mm, particularly when previous attempts at reconstruction with Silastic intubation or anastomosis of the canaliculi to the sac have been unsuccessful. This technique is useful in instances in which massive damage has occurred to the medial canthal region as a result of trauma, radiation, or prior surgical reconstruction. DCR is essential for the best placement and function of the tube. Placement without mucosal flaps reduces movement with blinking and allows for potential future dacryocystitis if the sac is not opened directly into the nose. If a DCR has been done in a prior surgical effort, the glass tube can be inserted by a closed approach (Fig. 55). When there has been no previous DCR, the steps described earlier for DCR are followed to the point at which flaps are formed in the nasolacrimal sac mucosa, which is an open approach for placement of the Pyrex tube (Fig. 56). A small portion of the caruncle may be excised to accommodate the tube. A sharp 23-gauge trocar or guide needle 30-mm long is passed at a 45-degree angle in an inferior and somewhat anterior direction through the lateral lacrimal sac wall and bony DCR ostium, and into the nose. If the path is blocked by the middle turbinate, a portion can be resected. Any severe deviations of the nasal septum should have been diagnosed by proper nasal examination before this surgical procedure. This may be facilitated by endoscopic examination. A 2-mm trephine can be slipped down the guide needle to cut a track into the nose at the proper angle. The maneuver will allow the tube to be slipped into place, but held tightly enough that it will not easily slip out of position during the postoperative period. The Luer-Lok portion of the needle is snapped off and the trephine is removed. A number 69 Beaver blade passed into the nose, adjacent to the trocar, can be used instead of the trephine. An appropriate length of Jones Pyrex tube is slipped over a probe and through the opening, into position. The tube should project 2 mm into the nose, but should not touch the nasal septum (Fig. 57). A single 6–0 nylon suture is passed through the hole in the tube collar or slipped around the neck of the tube, and tied tightly. The needle is passed behind the lid margin, deep into the posterior palpebral tissues at the medial canthus and tied. The DCR is then completed as previously described.
Postoperative management of the Pyrex tube is difficult in the pediatric age group but not impossible. Topical antibiotic drops are used four times per day for 2 weeks. In an adult, periodic syringing is easily done as an office procedure. In the pediatric age group, however, examination under anesthesia may be required to syringe adequately through mucus obstructions. The use of a contact lens wetting solution once daily is helpful in both pediatric and adult patients to reduce mucus formation. It is also helpful to instruct the patient to do the Valsalva maneuver by a quick inspiration with closure of the mouth and pinching both nostrils. In some instances, 10% N-acetylcysteine drops can be given several times daily. The mucolytic action of this agent sometimes will clear the tube. It is not harmful to the globe or adnexae, and obviously should be tried in the pediatric age group before subjecting a child to a general anesthetic.
Patients should be instructed to close their eyes or hold a finger over the medial canthal region when they sneeze or blow their nose. Otherwise, the tube can dislodge, even when secured with a suture. If a tube is lost, it should be replaced as soon as possible. The channel can be dilated with gold dilators (Weiss, Gunther Weiss), and a new tube of appropriate length slipped in over a probe. A suture can be used for fixation, as previously described.
ABNORMALITIES OF THE LACRIMAL SAC
Early probing for mucoceles (amniotoceles) and for neonatal dacryocystitis was discussed earlier. These entities usually are seen at birth or in the immediate postpartum period.33,110 The anlage or supernumerary duct (Fig. 58) is another congenital abnormality of the sac. With a supernumery duct, tears drain directly onto the face if the upper portion of the nasolacrimal system is open. Repair of a supernumerary duct can be accomplished by first injecting a small amount of methylene blue through a lacrimal cannula into the duct to outline the mucosal lining down to the lacrimal sac. An appropriately sized probe is placed into the supernumerary duct. An ellipse of skin is resected conservatively around the probe. The duct is traced down to the lacrimal sac, where it is ligated and cut (Fig. 59). A layered closure of muscle and skin is done. This type of simple closure will prove to be sufficient if there is no lower block to tear flow in the nasolacrimal duct. If there is a lower system block, however, Silastic intubation of the nasal duct or DCR will be required to eliminate this problem.
Neoplasms of the lacrimal sac can occur, and may present as functional blocks. Dacryocystography may be helpful in diagnosing these masses preoperatively. A frozen section is mandatory. Malignancy of the sac is one of the few indications for a dacryocystectomy. The nasopharynx should not be opened because of the potential risk of spread of a malignant tumor. Congenital entropion, distichiasis, or trichiasis can stimulate reflex tearing and cause epiphora. Appropriate steps should be taken to identify and surgically correct these problems. Ectropion of the punctum or lid is rare as a congenital problem.
Medial canthal or lacrimal sac tumors are best excised with careful margin and base controls.6,47,48 No attempt should be made initially to violate the bone or nasal mucosa. Canaliculoplasty to the lacrimal sac or Silastic intubation through the nasolacrimal duct can be considered. A DCR or Jones bypass tube should be avoided until at least 1 year has elapsed without clinical or radiographic evidence of tumor recurrence. This waiting period is mandatory to avoid seeding malignant cells into the nasopharynx. It is better for the patient to experience epiphora than to risk tumor seeding, which may have life-threatening consequences. Dacryocystectomy should be reserved for treatment of lacrimal sac tumors.112 It is not an appropriate technique for the relief of uncomplicated epiphora that results from lower system block. If necessary, bypass surgery can be done later, regardless of whether flaps, skin grafts, or granulation had been used to cover the dissected area in the medial canthal region.
MAJOR CONGENITAL CRANIOFACIAL DEFORMITIES
Any of the lacrimal abnormalities described above can occur singly or in combination with craniofacial anomalies. Repair for each entity is identical to that previously described for routine lacrimal problems. However, the timing of repair is different.111 Deformities such as telecanthus, epicanthal folds, orbital volume problems, and many canthal deformities can be managed during the initial craniofacial reconstruction. Specific nasolacrimal problems, however, except for simple dacryostenosis or acute dacryocystitis, are best treated after major bone shifts or on lay bone grafts in the midface region have been completed. Unfortunately, good results are too easily undone by subsequent surgery. Repeat lacrimal procedures are particularly difficult and have significantly less potential for success (Figs. 60 and 61).
RECONSTRUCTION OF THE LACRIMAL DRAINAGE SYSTEM AFTER TUMOR EXCISION
Lid tumors involving the punctum or canaliculus require careful excision under meticulous frozen section control or Mohs-type excision. However, a lid defect with a remaining proximal portion of the canaliculus can be repaired with a Silastic stent in a fashion similar to that described for canalicular lacerations (Figs. 62, 63, 64). Silastic tubing is passed through the normal punctum and canaliculus and brought out through the nasolacrimal duct. The other end, with the probe attached, is threaded into the remaining canalicular remnant. The lid is sutured into position, leaving a loop of Silastic that will form a pathway from the palpebral surface to the mucosa of the canaliculus. The tubing loop must be relatively loose to minimize the greater chances of cheesewiring that are present here.
11. Hurwitz JJ, Welham RA, Maisey MN. Intubation macrodacryocystography and quatitative scintillography: the “complete” lacrimal assessment. Trans Am Acad Ophthalmol Otolaryngol 81(4 pt 1):OP575, 1976
111. Whitaker L, Katowitz J: Facial anomalies involving the nasolacrimal apparatus. In Tessier P, Callahan A., Mustarde J, Saylor K, eds. Symposium on Plastic Surgery in the Orbital Region. St. Louis: CV Mosby, 1974<<?17>>