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At Issue: Endoscopic DCR vs. external DCR
Ocular Surgery News posed the following question to a panel of experts: Is endoscopic dacryocystorhinostomy (DCR) the new standard for nasal lacrimal duct surgery, or is the traditional external DCR more reliable?
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DALE R. MEYER, MD, FACS
External DCR remains gold standard
I believe the short answer to this question is “no,” and that external DCR still remains the gold standard for treating most forms of acquired nasal lacrimal obstruction in adults (and more complex congenital types).
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| Dale R. Meyer |
There is an increasing abundance of literature examining the effectiveness of endoscopic (endonasal) DCR; the relative indications, contraindications, advantages and limitations; as well as patient selection, surgical technique, postoperative care and complications in comparison with external DCR. While not universal, most studies have demonstrated lower success rates with endoscopic DCR. However, endoscopic DCR may be a reasonable option in many patients as a primary procedure or particularly for surgical revision after failed primary DCR. With the exception of avoidance of external incision scar, reported complications of endoscopic DCR appear to be similar. Disadvantages of endoscopic DCR include the preferred use/need of general anesthesia, expensive equipment and instrumentation, and relatively steep learning curve. While shorter operating time has been cited by some authors, total operating room time may actually be greater when equipment set-up is considered.
I discuss the advantages and limitations of both procedures with patients who are considering endoscopic surgery, typically because of concerns regarding the scar. In my own experience, I have found a success rate in excess of 97% with external DCR, performed now in most patients on an outpatient basis under local with sedation, using a small incision approach with tissue- adhesive superficial closure. Less than 1% of patients have reported the final incision scar as unsatisfactory. For (typically younger) patients highly concerned about the prospect of a scar, I offer endoscopic DCR, understanding that it will usually require general anesthesia and has a somewhat lower success rate. As advances in lacrimal surgery and modulation of wound healing evolve, it will certainly be exciting to see how even newer techniques of transcanalicular DCR develop.
For more information:
Dale R. Meyer, MD, FACS, can be reached at Ophthalmic Plastic Surgery, Lions Eye Institute, 1220 New Scotland Road, Suite 302, Slingerlands, NY 12159; 518-533-6540; e-mail: meyerd@mail.amc.edu.
JOHN B. HOLDS, MD
External DCR offers predictable results
Endoscopic dacryocystorhinostomy offers the theoretical advantages of avoidance of a skin incision with concomitant avoidance of scarring and neurovascular disruption along the tract exposing the lacrimal sac. In successful cases, healing can be quite uneventful with minimal ecchymosis and edema and delighted patients.
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| John B. Holds |
These advantages must be balanced against the increased equipment and potential manpower needs of endoscopic DCR, with generally higher rates of surgical failure and a diminished ability to deal with some processes, such as neoplasm, and some anatomic variations, as seen after trauma.
With careful technique, external DCR surgery seldom leaves a noticeable incision and has a surgical success rate of 96% or higher. Although endoscopic dacryocystorhinostomy has been reported to be this successful in isolated hands, relief of symptoms is often delayed and definition of success is sometimes more anatomic than functional. In the hands of occasional surgeons (often a team of an ophthalmologist and otolaryngologist), endoscopic DCR appears, from my referral population, to have a poor success rate.
Ultimately, my answer to this question has much to do with my general approach to surgery. I do not unnecessarily complicate surgery and tend to only embrace technology when it provides an irreplaceable advantage. Twice I have attempted to convert a significant number of my cases to endoscopic surgery. Each time, I have come back to external DCR because of the excellent, predictable results.
For more information:
John B. Holds, MD, can be reached at Ophthalmic Plastic and Cosmetic Surgery, 12990 Manchester Road, #102, Des Peres, MO 63131; 314-567-3567; fax: 314-567-6575; e-mail: eyelidmd@hotmail.com.
JAY JUSTIN OLDER, MD
Better exposure possible with external approach
As far as I know, both of these approaches have about the same results, but I prefer the external route because I have good exposure. The anatomy is seen directly, rather than through a scope.
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| Jay Justin Older |
After I make my skin incision, I dissect to the anterior lacrimal crest. I reflect the sac away from the lacrimal sac fossa and make an osteotomy with a drill and rongeur. I indent the lacrimal sac with a probe and make an anterior flap of lacrimal sac. I pass a cotton tip applicator up the nose to indent the nasal mucosa at the osteotomy, and then make an anterior flap of nasal mucosa. I pass the Crawford tubing through each canaliculus and out the nose with the help of a grooved director.
The tubing is tied in multiple knots and allowed to retract into the nose. The knot is placed just below the osteotomy to help prevent the tubing from looping in front of the eye. I then attach the anterior flap of nasal mucosa to the anterior flap of lacrimal sac. I do not pack the nose. If there is scarring in the area of the common canaliculus, I leave the tubing in for 3 months or longer. This approach has worked for me for many years.
For more information:
Jay Justin Older, MD, an affiliate professor of ophthalmology at the University of South Florida College of Medicine, Tampa, can be reached at 4444 E. Fletcher Ave., Tampa, FL 33613; 813-971-3846; e-mail: jolder1@tampabay.rr.com.
WILLIAM J. LIPHAM, MD, FACS
Creation of large bony ostium more important than approach used
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| William J. Lipham |
It is my opinion that the creation of a large bony ostium with an intact mucosal pathway is more important than the surgical approach that is utilized (external vs. endonasal) to obtain successful surgical outcomes with DCR surgery.
The American Academy of Ophthalmology investigated this issue in 2001 by reviewing 64 studies published between 1968 and 2000. At that time, only two comparative studies had been performed with 1 year follow- up, and the success rate for external DCR in both studies was 91% compared with 63% and 75% for the endonasal groups, with success defined as patency to irrigation. Since then, additional retrospective, comparative studies have demonstrated equivalent rates of success in both groups, although the success rates were 89% and 77%, respectively.
In my opinion, however, the most important predictor of surgical success is not the approach used (external vs. endonasal), but whether a large bony ostium is created and covered by lacrimal sac and nasal mucosa. In almost all cases, DCR failure is due to scarring and fibrosis of soft tissue surrounding the bony surgical ostium as it enters the nasal cavity. The most effective means of reducing this risk is by creating a large surgical bony ostium (1.5 cm in diameter) that is covered by anterior and posterior nasolacrimal sac and nasal mucosal flaps. When performed properly, the classically described external DCR is performed in such a manner and essentially converts the nasolacrimal sac into a lateral extension of the nasal cavity.
Many endonasal techniques, however, do not create a large ostium, (in particular, laser-assisted approaches) and do not attempt to maintain the integrity of the mucosa that promotes healing and reduces scarring of the adjacent soft tissue. To prevent scarring after endonasal surgery, a large number of endonasal surgeons utilize antimetabolites such as mitomycin-C to reduce the rate of fibroblast proliferation that may lead to scarring that closes the surgical ostium. The need to utilize antimetabolites to prevent ostial closure with endonasal procedures emphasizes the limitations of healing by secondary intention because mucosal surfaces are ablated with most endonasal approaches.
In 2004, a group from Australia described a prospective randomized clinical trial comparing a mechanical endonasal DCR technique (MENDCR) vs. conventional external DCR. This new MENDCR technique creates a large bony ostium with surgical anastomosis of mucosal flaps between the lacrimal sac and nasal mucosa to prevent future scarring. Their success rates comparing both techniques were about 95% for each group. The disadvantages of the endonasal approach appear to be related toward equipment costs (an endoscope and a nasal microdebrider) as well as a steep learning curve. To allow visualization and complete the procedure, a larger percentage of patients in the MENDCR group also required septoplasty (35%) and endoscopic sinus surgery (19%) that was not required with an external approach.
In summary, I do not feel that it is the approach that matters, but the fact that the surgeon creates a large bony ostium (1.5 cm in diameter) and lines it with both posterior and anterior lacrimal sac and nasal mucosal flaps. I currently perform external DCRs and place both a Crawford silastic stent and 10-0 French red rubber catheter between my anterior and posterior nasolacrimal sac and nasal mucosal flaps to promote primary mucosal healing. The rubber catheter is held in place with a 6-0 Vicryl suture and falls out about 1 month after surgery. I typically remove the Crawford silastic stents 6 months after the initial procedure. My success rate, as defined by patency to irrigation, with this approach is 93.7% for 623 consecutive cases.
For more information:
William J. Lipham, MD, FACS, can be reached at the Minnesota Eye Consultants, 9117 S. Lyndale Ave, Bloomington, MN 55420; 952-885-2479; e-mail: wjlipham@mneye.com.
References:
- Ben Simon GJ, Joseph J, et al. External versus endoscopic dacryocystorhinostomy for acquired nasolacrimal duct obstruction in a tertiary referral center. Ophthalmology. 2005;112(8):1463-1468.
- Dolman PJ. Comparison of external dacryocystorhinostomy with nonlaser endonasal dacryocystorhinostomy. Ophthalmology. 2003;110(1):78-84.
- Tsirbas A, Davis G, Wormald PJ. Mechanical endonasal dacryocystorhinostomy versus external dacryocystorhinostomy. Ophthal Plast Reconstr Surg. 2004;20(1):50-56.
- Woog JJ, Kennedy RH, et al. Endonasal dacryocystorhinostomy: A report by the American Academy of Ophthalmology. Ophthalmology. 2001;108(12):2369-2377.
CHARLES B. SLONIM, MD, FACS
Endoscopic DCR a good alternative procedure, but not the new standard
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| Charles B. Slonim |
Endoscopic DCR is not the new standard for nasolacrimal duct surgery. I believe traditional external DCR surgery is more reliable with an overall higher success rate.
DCR surgery failure is typically defined as having no improvement in epiphora, any recurrent episode of postoperative dacryocystitis, an obstruction to irrigation of the lacrimal system postoperatively and scarring of the intranasal osteotomy with no visualization of fluorescein dye. The oculoplastic and ENT literature has an abundance of articles describing the success rates of endoscopic vs. external DCRs. Endoscopic DCRs have always seemed to describe overall lesser success rates than those of traditional external DCRs.
Similar comparisons of complication rates of the two procedures also exist. The “endoscopists” boast the lack of a skin incision with no external surgical scar and less bleeding associated with violating the angular vasculature over the anterior lacrimal crest. The “externalists” boast the lack of nasal mucosal scarring, an “open-sky” view of the lacrimal sac, easier dacryolith retrieval (when present) and external scars that are barely visible postoperatively.
As an externalist for more than 25 years, I have enjoyed the same 92% to 96% success rate as my colleagues who also perform DCRs externally. I believe my surgical wounds, which are closed with Dermabond 99% of the time, are hardly visible postoperatively in the vast majority of my patients. I enjoy my open-sky view of the lacrimal sac.
I consider the endoscopic DCR a good alternative procedure to the traditional external DCR but not vice versa. Endoscopic DCRs are not the current standard of care for nasolacrimal duct surgery, and I do not see any evidence that they will be in the future.
For more information:
- Charles B. Slonim, MD, FACS, can be reached at Older and Slonim Eyelid Institute, 4444 E. Fletcher Ave., Suite D, Tampa, FL 33613; 813-971-3846; fax: 813-977-2611; e-mail: slonim@eyelids.net.
JULIAN D. PERRY, MD
With experience, endoscopic approach will gain favor
Various endonasal techniques have been used to perform dacryocystorhinostomy to minimize the scar associated with the external approach. A variety of endonasal techniques have been used with varying success rates.
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| Julian D. Perry |
More recent results in experienced hands suggest that the endonasal approach may result in similar success rates as external approach. Few head-to-head comparisons of the two techniques exist. Dr. Tsirbas and colleagues compared the endonasal approach to an external approach and found similar success rates, of 94% and 96%, respectively. Their technique involved creating a bony rhinostomy size of more than 15 mm using the endonasal technique. Dr. Ben Simon and colleagues also compared the two techniques and found better success with an endonasal approach. However, their overall success rate for DCR was lower than most previously published studies.
I do not think the endonasal technique is the new standard for treatment of nasolacrimal duct obstruction; however, with experience and proper technique, results certainly compare favorably. The external approach may allow for better visualization in cases in which underlying malignancy is suspected. The external approach may allow better visualization and avoidance of the common canaliculus. The scar created by external DCR surgery typically runs perpendicular to the relaxed skin tension lines and can be obvious in a small percentage of patients. Some surgeons create the incision running along the relaxed tension lines and into the lower eyelid to improve the resultant scar.
Both the endonasal and the external DCR techniques allow reliable improvement in symptoms due to nasolacrimal duct obstruction. The option of an endonasal approach should be discussed with the patient. As our expertise in endonasal approaches increases and as instrumentation improves, it is likely that the percentage of DCR performed through an endonasal approach will increase.
For more information:
- Julian D. Perry, MD, can be reached at Cole Eye Institute, Department of Ophthalmic and Plastic Orbital Surgery, 9500 Euclid Ave., Dept. I-20, Cleveland, OH 44195; 216-444-3635; e-mail: perryj1@ccf.org.