Nasal packing is rarely indicated but may be used to maintain hemostasis as needed.

Postoperative management and complications

As with powered endoscopic DCR or external DCR, significant morbidity is observed in the first 24 to 72 hours postoperatively in the form of hemorrhage. The patient is asked to refrain from nose-blowing for one week after the procedure to reduce risk of hemorrhage. Oxymetazoline hydrochloride 0.05% may be used, 1 to 2 sprays, every 10 to 12 hours to reduce minor bleeding along with pinching of the nose. The surgeon should be prepared to place nasal packing during the immediate postoperative period should the bleeding not be controlled.

A 5-day course of oral antibiotics and a topical antibiotic/ steroid drop is prescribed after surgery to reduce the risk of infection. If there was an active dacryocystitis at the time of surgery, I prefer to administer a 10-day course of antibiotics. Abscess or cellulitis rarely develops with prophylactic therapy and may require intravenous antibiotics.

Postoperative pain is typically minimal and well controlled with acetaminophen or acetaminophen with propoxyphene. In the absence of contraindications, a short course of systemic corticosteroids may be used in the immediate postoperative procedure or after stent removal. Stent removal occurs in the office approximately 2 to 3 months after surgery. The stent should be easily visualized in the nasal passageway with a headlight and nasal speculum. The stent is then transected at the interpalpebral thin portion and removed from the nasal passageway using bayonet forceps. Patients should avoid rubbing the corner of the eye; however the large diameter stent is exceedingly difficult to prolapse through the puncta given its design.

Discussion

In practiced hands, endoscopic DCR has attained success rates equivalent to that of external DCR. The 9 mm transnasal catheter makes endoscopic DCR easier and quicker by eliminating the need for powered instrumentation. The mechanical nature of the balloon catheter reduces tissue injury without disruption of the medial canthal anatomy and function. These advantages may make the external lacrimal surgeon more willing to transition to the endoscopic approach which is more readily accepted by patients because of the lack of a facial scar. Failures are typically related to ostium size and may be reoperated on using the endoscopic balloon-assisted DCR with a transcanalicular or transnasal catheter. External DCR or power-assisted endoscopic DCR always remain a viable option for revisional surgery when needed.

References

1.Toti A: Nuovo metodo conservatore di cura radicale delle suppurazioni croniche del sacco lacrimale (Dacriocistorinostomia). Clin Mod Firence 10:385-387, 1904

2.Dupuy-Dutemps L, Bourguet M: Procede plastique do dacryocystorhonostomie et ses resultat. Ann Ocul 158:241-261, 1921

3.Jones LT: The cure of epiphora due to canalicular disorders, trauma and surgical failures on the lacrimal passages. Trans Am Acad Ophthalmol Otolaryngol 66:506-510, 1962

4.Caldwell GW: Two new operations for obstruction of the nasal duct. NY Med J 57:581-582, 1893

5.Kennedy DW: Functional endoscopic sinus surgery. Technique. Arch Otolaryngol 111:643-649, 1985

6.Woog JJ, Kennedy RH, Custer PL, et al: Endonasal Dacryocystorhinostomy. A Report by the American Academy of Ophthalmology. Ophthalmology 108:2369-77, 2001

7.Francisco FC, Carvalho ACP, Francisco VFM, et al: Evaluation of 1000 lacrimal ducts by dacryocystography. Br J Ophthalmol 91:43-46, 2007

Congenital dacryocystocele (nasolacrimal duct cyst)

A congenital dacryocystocele develops when there is both an imperforate nasolacrimal duct distally and a valve-like obstruction at the junction of the common canaliculus and lacrimal sac proximally (Figure 1).1 Fluid accumulates, and the nasolacrimal duct system becomes distended. The proximal obstruction is attributed to distention of the sac compressing the canalicular system, causing a functional trap door-type block. The presence of such a functional obstruction can frequently be substantiated by the absence of an anatomical barrier on nasolacrimal probing, as well as by the common finding of a partially patent nasolacrimal drainage system on irrigation or dacryocystogram evaluation.2,3

Congenital dacryocystoceles typically present at birth or become apparent within the first few weeks of life as tear production increases. Epiphora is the most common manifestation. In many affected infants, a cystic mass of bluish coloration is noted in the medial canthal region. Infants with

Address reprint requests and correspondence: Michael Cunningham, MD, Harvard Medical School, Department of Otolaryngology, Massachusetts Eye and Ear Infirmary, 243 Charles Street, Boston, MA 021143096.

E-mail address: Michael_cunningham@meei.harvard.edu.

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congenital dacryocystoceles are at increased risk for secondary infection. Acute dacryocystitis, periorbital cellulitis, or orbital cellulitis in the neonatal age group should raise

suspicion of the potential existence of this congenital anomaly.4,5

As predicted by its embryologic development, a dacryocystocele should have a nasal component. The clinical association between congenital dacryocystocele and an ipsilateral intranasal cyst has been confirmed with a near 100% correlation when nasal endoscopy is used.6,7 In some infants, the dacryocystocele expansion may occur only intranasally; other children alternatively present with both an external medial canthal mass and an intranasal mass. Respiratory distress is commonly associated with congenital dacryocystocele with nasal extension because of the fact that infants are obligate nasal breathers; bilateral nasolacrimal duct cysts can cause life-threatening airway obstruction akin to that observed in infants with choanal atresia.8-11

All children with suspected dacryocystocele require a thorough nasal examination with flexible or rigid nasal endoscopy. Both nares should be examined, with a focus on the inferior meatus. The application of a topical decongestant such as oxymetazoline hydrochloride to the nasal mucous membranes before endoscopy enhances visualization. A cystic mass arising from the undersurface of the inferior

Figure 1 The combination of a valve-like obstruction at the junction of the common canaliculus and the lacrimal sac proximally (A) and an imperforate nasolacrimal duct distally (B) predispose to congenital dacryocystocele formation. (Color version of figure is available online.)

turbinate is sought; at times only redundant mucosa without an obvious cyst is apparent. If a mass is present, it will be soft and compressible when palpated with a nasal probe or suction.

Computed tomography (CT) is the study of choice if radiographic evaluation is performed. The classic CT characteristics of a congenital dacryocystocele include the triad of a medial canthal cystic mass, a dilated ipsilateral nasolacrimal duct, and an intranasal cystic mass in continuity.12 The intravenous administration of iodinate contrast agents may demonstrate a slight rim of enhancement of these dilated cystic structures.13 The use of CT additionally provides excellent detail of the surrounding osseous nasal anatomy.

Surgical intervention is indicated if a dacryocystocele presents with associated acute or chronic dacryocystitis, if the external medial canthal cyst is large and visually obstructive, or if there is an intranasal cyst causing respiratory distress. A joint otolaryngologic and ophthalmologic sur-

gical treatment of congenital dacryocystocele is recommended.3,6,7 When there is an identifiable intranasal cyst,

marsupialization with endoscopic excision of the medial cyst wall is preferred over simple cyst puncture with decompression. Even in cases in which there is no evident intranasal cyst, the removal of redundant mucosa from the lateral inferior meatal wall in the presumed region of the valve of Hasner effectively treats the distal obstruction. Cyst marsupialization is best performed in endoscopic instrumental fashion by using appropriately sized, straight or angled, biting forceps (Figure 2). Laser mucosal vaporiza-

tion is an alternative approach but adds unnecessary time and cost without improved effectiveness. Anesthesia and intraoperative preparation arrangements are identical to those described in the following section on endoscopic dacryocystorhinostomy.

Concomitant nasolacrimal probing and irrigation is necessary to ascertain nasolacrimal system patency. Typically after the nasolacrimal sac has been decompressed distally, the proximal one-way valve of Rosenmuller will be able to function normally. Silicone intubation of the lacrimal outflow system may be performed but is not necessarily required.

Pediatric endoscopic dacryocystorhinostomy

Symptomatic congenital obstruction of the nasolacrimal system is a common clinical problem, estimated to be present in approximately 5% to 6% of newborns.14 Clinical signs and symptoms depend on the nature and anatomic level of the obstruction. Most commonly, the obstruction is distal at the level of the valve of Hasner between the nasolacrimal duct and nasal cavity. Proximal obstruction

Figure 2 The intranasal portion of a dacryocystocele is best marsupialized endoscopically with appropriately sized straight or angled biting forceps. (Color version of figure is available online.)

Figure 3 The rhinostomy portion of an endoscopic DCR begins with incision of the nasal mucosa with a 15 blade (shown), sickle knife or angled keratotomy knife. IT, inferior turbinate; MT, middle turbinate. (Color version of figure is available online.)

involving the canaliculi, common canaliculus or lacrimal sac occurs less frequently. Additional congenital nasolacrimal anomalies associated with tear flow obstruction include dacryocystoceles as previously described, agenesis of the puncta or canalicular structures, congenital lacrimocutaneous fistula, and nasolacrimal obstruction secondary to craniofacial dysmorphism.15

Uncomplicated congenital nasolacrimal obstruction spontaneously resolves in 85 to 95% of children by one year of age.16 Most children with distal nasolacrimal duct obstruction who remain symptomatic respond to a single probing and irrigation procedure; a small percentage will require repeat probing with or without silicone intubation of the nasolacrimal system.17 For those children with persistent nasolacrimal obstruction refractory to such treatment measures, additional surgical correction in the form of dacryocystorhinostomy (DCR) is indicated; surgical intervention by means of DCR is also advocated for children with chronic or recurrent dacryocystitis.18

The role of external DCR as a safe and effective procedure in the pediatric population is well-established with overall success rates of 83% to 96%.19-21 The greater rates of success are achieved with primary procedures performed for uncomplicated congenital nasolacrimal obstruction; children requiring revision procedures and those with acquired nasolacrimal obstruction secondary to trauma or prior infection do comparatively less well. Since the advent of instrumentation and techniques appropriate for pediatric endoscopic sinus surgery, several groups have confirmed the value of endoscopic DCR as a highly successful alternative to external DCR in children.22-25

Endoscopic dacryocystorhinostomy is facilitated by a joint otolaryngologic and ophthalmologic team approach. General anesthesia typically is necessary in children. The child is positioned in standard sinus surgical fashion and

draped such that both the nose and affected eye are included in the operative field. Confirmatory lacrimal probing and irrigation, as well as intraoperative dacryocystography, may be performed before DCR when indicated.

Both the 4-mm and 2.7-mm endoscopic telescopes with 0-degree and 30-degree viewing angles should be available for intraoperative use. Operative intervention with the 4-mm telescopes is preferred because of their better illumination and wider field of vision. The narrow anatomical dimensions of the young child’s nasal airway may dictate the use of the 2.7-mm telescopes in certain cases. The use of a video monitor display enhances participation by all members of the surgical team.

Hemostasis is important for adequate intraoperative visualization. Initial topical vasoconstriction is performed with 0.05% oxymetazoline hydrochloride solution, followed by submucosal infiltration of the lateral nasal wall (and middle turbinate, if necessary) with 1% lidocaine with 1:100,000 epinephrine. Topical 4% cocaine solution (maximum dose 1 mg/kg) may also be required once tissue disruption commences; this is particularly true in revision cases with extensive soft tissue scarring.

An extremely important step in the successful performance of endoscopic DCR is proper identification of the lacrimal sac. The maxillary line is a valuable anatomic landmark in this regard; the lacrimal sac is located lateral to the maxillary line at its superior aspect.26 Identification of the lacrimal sac is further enhanced by the passage of a rigid fiberoptic light probe through the superior or inferior punctum into the lacrimal sac. The transilluminated lacrimal sac can readily be visualized through the lateral nasal wall. The position of the sac will determine whether a partial anterior middle turbinectomy is necessary for adequate surgical access.

Figure 4 The elevated nasal mucosa is excised with appropriately sized biting forceps to allow access to the underlying lacrimal bone. IT, inferior turbinate; MT, middle turbinate. (Color version of figure is available online.)

The rhinostomy portion of the endoscopic DCR consists of the separate removal of nasal mucosa and nasal bone. The nasal mucosa is initially incised with a 15 blade, sickle knife, or angled keratotomy knife (Figure 3). A mucosal flap is elevated. This mucosal flap can be preserved or alternatively removed with appropriately sized angled biting forceps (Figure 4). If removed, a 1.5- to 2.0-cm diameter segment of nasal mucosa is typically excised.

Removal of the underlying lacrimal bone commences. This step is more easily performed posteriorly where the bone is thinner but is more safely begun anteriorly to avoid the possibility of orbital disruption. Guidance with the fi- beroptic light probe significantly decreases this risk. Highspeed drilling with the use of a hooded tip burr is an effective means of initial bone removal. Angled neurosurgical microrongeurs and otologic curettes may then be used to enlarge the bony ostium to the desired 1.0 to 1.5 cm size (Figure 5).

The dacryocystostomy is performed next. The medial wall of the lacrimal sac can be “tented” with the fiberoptic light or with a standard lacrimal probe to facilitate sac incision (Figure 6). The sac wall can be quite thick secondary to previous inflammation. The sac is incised with either an angled keratotomy knife, sickle knife or myringotomy knife; alternatively a laser may be used. In adults the lacrimal sac flaps are ideally anastomosed to the adjacent nasal mucosa.27,28 Such flap anastomosis is technically difficult in children. Angled endoscopic biting forceps are alternatively used to create a lacrimal sac opening of approximately 1.0 cm in diameter.

After completion of the dacryocystostomy, nasolacrimal system patency is confirmed by bicanalicular irrigation and subsequent silicone tubing intubation through the surgically created nasolacrimal fistula (Figure 7). The ends of the tubing are knotted so that there is one continuous loop through the inferior and superior canaliculi, common canal-

Figure 6 The lacrimal sac mucosa is “tented” medially with a lacrimal probe or fiberoptic endoilluminator to facilitate the dacryocystostomy. (Color version of figure is available online.)

iculus, nasolacrimal sac, and intranasal ostium (Figure 8). A biodegradable nasal stent is placed between the lateral nasal wall and middle turbinate only if needed to medialize an unstable turbinate remnant. No packing is used. The nostril is filled with clindamycin phosphate topical gel. Ophthalmic antibiotic steroid drops are topically applied.

Endoscopic pediatric DCR procedures typically are performed as ambulatory procedures, with patients being dis-