Figure 6 After removal of the overlying bone, the lacrimal sac is incised with a sickle knife.

As noted earlier, concomitant ethmoidectomy may be required to provide adequate access to the anterior lacrimal sac. Other procedures, including uncinectomy, middle turbinectomy, and septoplasty, may also facilitate exposure of the lateral nasal wall. These adjunctive procedures are especially useful in revision cases of EDCR.

Postoperative care

The patient is placed on a combination antibiotic-steroid eye drop, such as sulfacetamide–prednisolone acetate,

Figure 8 The closed loop acts as stent for the newly created rhinostomy.

which is to be 4 times daily for 2 weeks. The patient also is instructed to perform frequent nasal saline irrigations. Any remaining debris is removed from the operative site at the first postoperative visit 1 week after surgery. The Silastic tubing used to stent the surgical ostium is typically removed 6 weeks after surgery by cutting the exposed tubing at the medial canthus and withdrawing it through the nose. Patency of the lacrimal drainage system is verified by endoscopic observation of fluorescein dye flowing from the eye through the rhinostomy site into the nose.

Figure 7 After the medial sac wall has been resected, a bicanalicular tube is placed by intubating both canaliculi, with subsequent retrieval of the probes from the rhinostomy site.

Results

The success rates of primary EDCR in several recent series exceed those obtained in earlier reports, and in some cases match the 90% to 95% success rates obtained with external DCR.15-17 The reported improvement in surgical outcomes may reflect a collective “learning curve”-type effect among surgeons performing this procedure.18

Complications

The most common complication of endoscopic DCR is failure of the procedure with persistence of epiphora.19 This may result from fibrous occlusion of the rhinostomy site or the presence of synechiae between the lateral nasal wall and middle turbinate or nasal septum. Failure to open the entire portion of the lacrimal sac satisfactorily may result in continued epiphora due to accumulation of lacrimal debris in the residual sac (lacrimal sump syndrome).20 Other potential complications include orbital injury, postoperative bleeding, and sinusitis.

Conclusions

Endoscopic surgery for lacrimal outflow obstruction is a safe and effective alternative to traditional external DCR surgery. EDCR is particularly advantageous in patients with concomitant sinonasal disease, patients with a previous history of radiation therapy, pediatric patients, and in revision procedures. Advantages include excellent visualization, the ability to thoroughly evaluate the location and size of the rhinostomy site, and the avoidance of a facial scar. Recent studies suggest that the success rates of endoscopic DCR are comparable to those achieved through external approaches.

References

1.Caldwell GW: Two new operations for obstruction of the nasal duct, with preservation of the canaliculi. Am J Ophthalmol 10:189-192, 1893

2.West JM: A window resection of the nasal duct in cases of stenosis. Trans Am Ophthalmol Soc 12:654, 1914

3.Mosher HP: Re-establishing intranasal drainage of the lacrimal sac. Laryngoscope 31:492-521, 1921

4.Metson R: The endoscopic approach for revision dacryocystorhinostomy. Laryngoscope 100:1344-1347, 1990

5.Massaro BM, Gonnering RS, Harris GJ: Endonasal laser dacryocystorhinostomy: A new approach to nasolacrimal duct obstruction. Arch Ophthalmol 108:1172-1176, 1990

6.Woog JJ, Sindwani R: Endoscopic dacryocystorhinostomy and conjunctivodacryocystorhinostomy. Otolaryngol Clin North Am 39:10011017, 2006

7.Bartley GB: Acquired lacrimal drainage obstruction: an etiologic classification system, case reports, and a review of the literature. Part 1. Ophthal Plast Reconstr Surg 8:237-242, 1992

8.Chastain JB, Cooper MH, Sindwani R: The maxillary line: anatomic characterization and clinical utility of an important surgical landmark. Laryngoscope 115:990-992, 2005

9.Yung MW, Hardman-Lea S: Endoscopic inferior dacryocystorhinostomy. Clin Otolaryngol Allied Sci 23:152-157, 1998

10.Mortimore S, Banhegy GY, Lancaster JL, et al: Endoscopic dacryocystorhinostomy without silicone stenting. J R Coll Surg Edinb 44: 371-373, 1999

11.Deka A, Bhattacharjee K, Bhuyan SK, et al: Effect of mitomycin C on ostium in dacryocystorhinostomy. Clin Exp Ophthalmol 34:557-561, 2006

12.Chan KO, Gervais M, Tsaparas Y, et al: Effectiveness of intraoperative mitomycin C in maintaining the patency of a frontal sinusotomy: A preliminary report of a double-blind randomized placebo-controlled trial. Am J Rhinol 20:295-299, 2006

13.Zilelioglu G, Ugurbas SH, Anadolu Y, et al: Adjunctive use of mitomycin C on endoscopic lacrimal surgery. Br J Ophthalmol 82:63-66, 1998

14.Camara JG, Bengzon AU, Henson RD: The safety and efficacy of mitomycin C in endonasal endoscopic laser-assisted dacryocystorhinostomy. Ophthal Plast Reconstr Surg 16:114-118, 2000

15.Tsirbas A, Davis G, Wormald PJ: Mechanical endonasal dacryocystorhinostomy versus external dacryocystorhinostomy. Ophthal Plast Reconstr Surg 20:50-56, 2004

16.Apaydin KC, Fisenk F, Karayalcin B, et al: Endoscopic transnasal dacryocystorhinostomy and bicanalicular silicone tube intubation. Ophthalmologica 218:306-311, 2004

17.Metson R, Woog JJ, Puliafito CA: Endoscopic laser dacryocystorhinostomy. Laryngoscope 104:269-274, 1994

18.Onerci M, Orhan M, Ogretmenoglu O, et al: Long-term results and reasons for failure of intranasal endoscopic dacryocystorhinostomy. Acta Otolaryngol 120:319-322, 2000

19.Fayet B, Racy E, Assouline M: Complications of standardized endonasal dacryocystorhinostomy with unciformectomy. Ophthalmology 111:837-845, 2004

20.Migliori ME: Endoscopic evaluation and management of the lacrimal sump syndrome. Ophthal Plast Reconstr Surg 13:281-284, 1997

Endoscopic approaches to lacrimal surgery have gradually gained acceptance during the past few years. Advances in endoscopic technology and powered instrumentation have contributed to increased success in endoscopic dacryocystorhinostomy (DCR). Established advantages of the endoscopic approach include the absence of external incision and scar, preservation of the orbicularis oculi pump mechanism, preservation of medial canthal anatomy, improved visualization, decreased operating time, decreased intraoperative bleeding, and the ability of the surgeon to address concurrent intranasal pathology, including septal deviations and ethmoid disease. Anecdotally, the endoscopic approach has been associated with less pain and favorable patient satisfaction in our practice. Unfortunately, failure rates in the 5-20% range have been encountered in both external and endoscopic primary DCR.1-3

Several operative factors may contribute to surgical failure, including poor visualization, limited understanding of intranasal anatomy, inadequate bone removal or mucosal marsupialization, and/or suboptimal instrumentation. Pa- tient-related factors may also play a part, as it has been demonstrated that patients who fail the first revision surgery are more likely to fail subsequent revisions.4 Failure of primary surgery is widely accepted to be a result of scar formation or ostial stenosis.5,6 With a mucosal-preservation endoscopic-powered technique, the ostium has been shown

Address reprint requests and correspondence: Todd T. Kingdom, MD, Department of Otolaryngology-Head and Neck Surgery, 12631 E. 17th Avenue, B205, PO Box 6511, Aurora, CO 80045.

E-mail address: todd.kingdom@uchsc.edu.

1043-1810/$ -see front matter © 2008 Elsevier Inc. All rights reserved. doi:10.1016/j.otot.2008.10.002

to shrink slightly within the first month but then to stabilize over time.7 Although there is no compelling evidence to indicate that the size of the ostium correlates with outcome, this premise is generally accepted. In actuality, the limited literature available on findings at the time of revision surgery cites other sinonasal obstructive factors along with incomplete initial surgery as the 2 major causes of DCR failure.8 Hence, in the setting of revision surgery, certain goals are paramount: (1) a thorough understanding of intranasal endoscopic anatomy, including the location and extent of the lacrimal sac; (2) efficient bone removal to achieve complete exposure of the lacrimal sac; and (3) careful and complete incision and marsupialization of the lacrimal sac.

Indications

DCR is indicated for the treatment of congenital or acquired nasolacrimal duct obstruction (NLDO), which may present with epiphora and/or infection. Epiphora may be unilateral or bilateral, constant or intermittent. Risk factors include trauma, paranasal sinus disease or surgery, systemic inflammatory disease, previous inflammation of the lacrimal sac, or ingestion of considerable doses of radioactive iodine. Surgical failure may be defined as persistent subjective tearing associated with objective establishment of impaired drainage. Objective findings diagnostic of surgical failure include reflux of irrigant during lacrimal probing and irrigation, or endoscopic visualization of stenosis or obstruction of the neo-ostium.