|Year : 2015 | Volume
| Issue : 1 | Page : 19-22
Transition from external to endonasal endoscopic dacryocystorhinostomy: Learning curve of an oculoplasty surgeon
Ishan Acharya1, Hakobyan Sevada1, Harsh Shah1, Milind Nene2, Jitendra Jethani3
1 Department of Ophthalmic Plastic Surgery, Orbit, Ocular Oncology and Ocular Prosthesis, Vadodara, Gujarat, India
2 Department of Consultant Otolaryngologist, Nene Hospital, Vadodara, Gujarat, India
3 Department of Paediatric Ophthalmology and Squint Surgery, Dr. Thakorbhai V. Patel Eye Institute, Vadodara, Gujarat, India
|Date of Submission||31-Dec-2013|
|Date of Acceptance||29-May-2014|
|Date of Web Publication||14-Jan-2015|
Department of Ophthalmic Plastic Surgery, Orbit, Ocular Oncology and Ocular Prosthesis, Dr. Thakorbhai V. Patel Eye Institute, Haribhakti Complex, Vinoba Bhave Road, Salatwada, Vadodara - 390 001, Gujarat
Source of Support: None, Conflict of Interest: None
Purpose: The purpose was to elaborate difficulties encountered during the transition from external dacryocystorhinostomy (Ex-DCR) to endonasal endoscopic DCR (EN-DCR) by an oculoplasty surgeon and to evaluate the outcome of EN-DCR. Materials and Methods: A retrospective study of consecutive 24 patients who presented with epiphora and underwent EN-DCR between August 2008 and December 2009. All procedures except for one case were performed under general anesthesia and under the direct visualization of the rigid fiberoptic endoscope (Hopkin II, 30°, Karl Storz, Germany, endoscope). Success was measured by both improvement of the epiphora and patency of the lacrimal system on irrigation. Results: The total of 25 EN-DCRs were performed of which the first 12 together with an otorhinolaryngologist. Of 24 patients 18 were females and 6 were males. The mean age was 43.8 ± 20.2 years. In one patient, the procedure was performed bilaterally. After an average follow-up 15.92 ± 4.57 months, success was achieved in 92% of all patients. No significant intra- and post-operative complications were detected. Conclusion: The success rate of EN-DCR was 92%. The success rate of EN-DCR compares favorably with Ex-DCR. We are of the opinion that the surgery is best learned in conjunction with an otorhinolaryngologist ENT surgeon who has expertize in endoscopic nasal surgery. Although the learning curve of EN-DCR is steep and requires thorough knowledge of nasal anatomy it is to be performed by an oculoplastic surgeon to keep up with the times.
Keywords: Dacryocystorhinostomy, endonasal, external, endoscope
|How to cite this article:|
Acharya I, Sevada H, Shah H, Nene M, Jethani J. Transition from external to endonasal endoscopic dacryocystorhinostomy: Learning curve of an oculoplasty surgeon. J Clin Ophthalmol Res 2015;3:19-22
|How to cite this URL:|
Acharya I, Sevada H, Shah H, Nene M, Jethani J. Transition from external to endonasal endoscopic dacryocystorhinostomy: Learning curve of an oculoplasty surgeon. J Clin Ophthalmol Res [serial online] 2015 [cited 2019 Jun 19];3:19-22. Available from: http://www.jcor.in/text.asp?2015/3/1/19/149347
Endonasal dacryocystorhinostomy (DCR) was first proposed by Caldwell.  Caldwell used an electric burr to create a middle meatal osteotomy in the area marked by a metal probe. This probe was passed through the nasolacrimal duct (NLD) to identify the area of blockage. The technique was modified by West who introduced the idea of a window osteotomy by removal of the lacrimal bone and the superior maxilla to access the NLD.  However, unlike the external DCR (Ex-DCR), the endonasal approach was limited by technical difficulties: Difficulty in visualizing the surgical site, achieving effective soft tissue and bone removal, and controlling hemorrhage. Hence, the popularity of endonasal DCR did not increase until Rice's Cadaver study demonstrated that endoscopic DCR (EN-DCR) was a viable option.  With the introduction of operating microscopes, rigid and semi-rigid nasal endoscopes, and fiberoptic delivery systems, surgeons were able to evaluate intranasal anatomy more precisely. The first clinical study of endonasal EN-DCR was published by McDonogh and Meiring.  With the advent of the rigid fiberoptic endoscope and its use in paranasal sinus surgery, there has been renewed interest over the past two decades in endonasal surgery to correct primary and recurrent NLD obstruction. 
Advantages of EN-DCR over the external approach include lower morbidity, reduced intraoperative bleeding, shorter operative time, early rehabilitation, and preservation of pump function since the orbicularis oculi muscle, presac fibers, and medial canthal tendon are not disrupted.  There is no external scar, which is of paramount importance to young patients and to many others aware of the no-scar alternative. It is possible to address nasal and sinus abnormalities through the same surgical approach. The disadvantages of EN-DCR are small rhinostomy size, higher equipment costs, and a steep learning curve.  We did not find any article in literature clearly elaborating difficulties faced by an oculoplasty surgeon. Hence, our primary aim of this study was to elaborate the difficulties faced by an oculoplasty surgeon and to evaluate the outcome of EN-DCR surgery.
| Materials and Methods|| |
Data of all patients who underwent EN-DCR between August 2008 and December 2009 was reviewed. Total 25 EN-DCR were performed. This study was approved by Institutional Ethics Board Committee. Ophthalmologic examination was performed, including documentation of tear meniscus height, examination of the eyelids for punctal malposition, horizontal laxity, or orbicularis weakness. Compression over the lacrimal sac identified any mucoid or purulent reflux. Irrigation of the NLD through the canaliculi was performed to assess the outflow. Diagnostic probing was done to rule out canalicular or common canalicular block in case regurgitation of fluid was absent on pressure on lacrimal sac area. A standard nasal examination was performed to detect any septal deviation, middle turbinate hypertrophy, nasal polyps, or any other intranasal abnormality that could affect intranasal surgery.
Patients with traumatic NLD obstruction, canalicular obstruction and significant nasal pathology were excluded. The patients with significant septal deviation and secondary DCR were operated along with the otolaryngologist (Dr. MN) only. Patients with NLD obstruction were offered the choice of a DCR by either external or endonasal approach, and informed consent was obtained. In all cases, preoperative lacrimal pathways assessment included irrigation of the nasolacrimal system and lacrimal probing.
All procedures except for one case were performed under general anesthesia and under the direct visualization of the rigid fiberoptic endoscope (Hopkin II endoscope, 30°, Karl Storz, Germany) coupled to a video camera and a display unit. The surgeon's position was on the patient's right side for both right and left EN-DCR.
Using a nasal speculum, the lateral wall of the nose was infiltrated with local anesthetic (2% lidocaine with 1:100,000 epinephrine). Soaked cotton pledges with epinephrine 1:100,000 and lidocaine 2% were used to decongest the nasal cavity for 10 min. Pretreatment with nasal decongestants helped shrink the nasal mucosa and maximize the space around the middle turbinate available for manipulation of the instruments and visualization. The soaked pledges were removed, and a rigid nasal endoscope (30° Hopkins II endoscope; Karl Storz, Germany) was inserted into the nose. The lateral wall of the nose was visualized, and attention was paid to the anterior middle turbinate. The anterior incision was performed slightly anteriorly and superiorly (≈8-10 mm) to the middle turbinate down to the bone with a number 15 blade and extended 1 cm to an area superior to the insertion of the inferior turbinate. The posterior vertical incision, parallel to the anterior, was placed on the posterior edge of the crista maxillaries (maxillary line), in front of the uncinate process. Both incisions are joined vertically. Superioposteriorly based mucosal flap was created and hinged posteriorly. Overlying hard thick bone of the frontal process of the maxilla excised with the help of forward-biting Kerrison Bone Rongeur and the inferior half of the sac uncovered. Care was taken to slip the instrument between the bone and the lacrimal mucosa to avoid undue bleeding or damage to the lacrimal sac [Figure 1]. Once the lacrimal sac mucosa was encountered, the lacrimal sac was tented into the surgical site with the 00 Bowman probe, and the medial wall of the lacrimal sac was incised using a sickle knife [Figure 2]. Bi-canalicular silicone tubes intubation was performed in seven patients (with previously failed other procedures and fibrotic sacs) by passing the lacrimal tubes through the upper and lower canaliculi and retrieving them endoscopically. Metal ends of the tubes were cut, and the tube was tied with a square knot and left in the nasal cavity. Postoperatively, topical antibiotic drops of ofloxacin 0.3% and dexamethasone 0.1% as well as fluticasone intranasal spray were administered 4 times and once a day respectively for 2 weeks. Nasal douche with normal saline solution was advised 3 times a day for 4 weeks postoperatively to flush debris from the surgical site.
|Figure 1: (a) Normal intranasal anatomy (b) two parallel incisions, one just above the insertion of the middle turbinate and other 1 cm apart posteriorly (c) mucosa hinged superoposteriorly (d) bone punch in situ for creating osteotomy|
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|Figure 2: (a) Lacrimal sac is being tented by probe (b) completely opened lacrimal sac and direct observation of common canalicular opening (c) fluorescein stained dye coming out of the sac|
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Postoperatively, patients were examined at 1 day, 1 week, 1 month, 3 months, 6 months, and 1 year. Postoperative epistaxis, pain, tearing and epiphora, periorbital edema and ecchymosis, nasal discharge, olfactory abnormality, and silicone tube position were assessed at every follow-up visit. Silicone tubes were removed after 8 weeks. Success was defined as both absence of epiphora symptomatically and anatomic patency of the lacrimal drainage pathway (assessed by lacrimal syringing).
| Results|| |
Of 25 surgeries performed, 18 were females, mean age 46.1 ± 17.2 years, and 6 were males, mean age 36.8 ± 28.4 years. One female underwent bilateral surgery. Three patients had been previously treated some years earlier elsewhere, two patients by an external approach, and one by transcanalicular LASER DCR. Two pediatric patients (mean age 43 months) were treated unsuccessfully with probing prior to EN-DCR. All patients presented with epiphora, 18 of them had positive regurgitation and three had negative regurgitation on pressure over the lacrimal sac. A total of 25 surgeries were performed. Of 25 surgeries, 12 were performed together with an otorhinolaryngologist (MN) and 13 independently by the first author (IA).
The average patient age was 43.8 ± 20.2 years. Eighteen surgeries (72%) were performed on the right side and seven (28%) on the left side. Twenty (80%) cases had chronic dacryocystitis and five (20%) had a history of other failed interventions: Two (8%) after Ex-DCR, one (4%) after transcanalicular LASER DCR and 2 (8%) pediatric cases after failed NLD probing. In 4 (16%) patients concurrent septoplasties were performed. The mean duration of surgery was 30 min when performed by the otolaryngologist. The mean duration of surgery was 55 min for the first 10 surgeries performed by the first author (IA) which reduced to 40 min in last three surgeries. The author has to postpone three cases taken for EN-DCR. Of the three cases, in two cases the reason was high deviated nasal septum occluding the view of the middle turbinate completely even after sufficient decongestion by adrenaline soaked gauze, one male patient had very tough maxillary bone and so endonasal route was abandoned, and the surgery was completed externally. Average follow-up period was 15.92 ± 4.57 months. Evaluation included asking about subjective symptoms of epiphora and lacrimal syringing. In children lacrimal irrigation was not performed. Silicone tube was removed after 8 weeks. Failure was noted only in two patients. The reason for failure in one patient was the reformation of sac probably due to diverticulum of sac. The lacrimal system was patent on syringing. The patient had a very large mucocele preoperatively. In other patient, the ostium was completely closed. This patient had fibrotic and shrunken sac. The first patient was operated for Ex-DCR and the other patient underwent revision EN-DCR with silicone tube with a successful outcome.
| Discussion|| |
Dacryocystorhinostomy is an elective procedure, which aims to alleviate epiphora. Although Ex-DCR is still the most widely done surgical intervention for treating chronic dacryocystitis in our country, due to improved success rates, many surgeons prefer to use the endonasal approach as it has several distinct advantages over the external procedure. These include a shorter operating time with better homeostasis, less postoperative pain relief requirement, no cutaneous scar, no risk to medial canthal structures, and lastly, potential for the procedure to be performed as a day case under local anesthetic.  Other additional factors may affect the choice of approach, such as patient comorbidities, underlying lacrimal pathology, previous nasal surgery, the individual surgeon's experience, and even operating costs.
The success of an EN-DCR is completely contingent upon a thorough knowledge of the intranasal anatomy since anatomical variations inside the nasal cavity are likely to affect the outcome of the EN-DCR surgery. Narrow nasal cavity, deviated nasal septum can be challenging and demanding for endoscopic procedure, in which extra time or additional procedures might be required.
Foremost point in transition from Ex-DCR to EN-DCR is a commitment to change with time. Many oculoplasty surgeons are excellent at Ex-DCR with very high success rate. And that high success rate prevents them to learn a new technique for the same surgery. To shift to EN-DCR may be very challenging for them as one may have initial disappointments with the results. Oculoplasty surgeons wishing to take up EN-DCR surgery need to be thoroughly familiar with the intranasal anatomy. The first difficulty comes in holding the scope. There are two specific ways of holding the scope [Figure 3]. If the surgeon is right handed, he will hold the scope with his left hand and vice versa. To start with, the author would like to learn the surgery with 30° scope as it's a very good compromise between 0° and 45° scopes, which can confuse the surgeon in real-time location of the scope in the nose. 30° scope will give a better angular view of the lacrimal sac area- the area with which he is more concerned. The second difficulty is the orientation of the scope and camera. While operating for EN-DCR, the bevel of a 30° scope should face upwards and slightly laterally toward the lateral wall of the nose. This will make the intranasal structures almost vertically oriented in the view, which in turn makes manipulation of instruments easier. After orienting the scope, the third difficulty is in introducing the scope in the nasal cavity without touching either the lateral or septal wall of the nose. This becomes more and more difficult and sometimes irritating as the surgery proceeds and blood starts staining the scope. Again a septoplasty will make the job more frustrating for an oculoplasty surgeon. The fourth problem comes, while getting adapted to a monocular view of the nose. As an ophthalmic or an oculoplasty surgeon, he has never operated while seeing on TV monitor. This makes subsequent steps more difficult. Hence, it becomes difficult for a learning oculoplasty surgeon to perform this type of multitasking- maintaining orientation of camera, viewing TV monitor, stabilizing one hand with the camera for constant and steady view of the operative site and manipulating instruments with the other hand- all at once within narrow space of the nose. After all these challenges, real challenge starts when you put first two incisions in the nasal mucosa. While putting the mucosal incisions, the difficulty is to make them parallel to each other and making them deep to the bone. Especially, the joining incision is difficult to make deep to the bone as the blade is almost tangential to the mucosal surface because of lack of space. It is very important to make this initial flap broad enough to get enough exposure and without any mucosal-tags to avoid obstruction to the field. Again, the flap has to be repositioned to cover the bare bone at the end of surgery to minimize secondary granulation tissues. While operating the surgeon has to keep on changing suction cannula with other instruments to remove the blood from the operative field. Initial bone-punching is easier, but as one goes anterosuperiorly, it becomes difficult to remove the thick maxillary bone. A bony-spur, just beside the insertion of the middle turbinate, is almost always difficult to remove. Once a while one may have to use motorized instrument to remove the thicker bone. Opening the lacrimal sac completely is a very important step to avoid failure. Sickle knife has to be put as anterosuperiorly as possible under the anterior edge of osteotomy, and after a stab incision the knife is carried posteriorly and inferiorly in sawing manner along the anterior edge of osteotomy to open the sac as completely as possible. A fibrotic and shrunken sac is difficult to open. If a surgeon finds such a sac intra-operatively, he should put silicone stent to prevent failure.
It is our opinion that the surgery is best learnt together with an otorhinolaryngologist surgeon who has expertise in endoscopic nasal surgery. In our case, 12 surgeries were performed by the first author under the guidance of an experienced otorhinolaryngologist before embarking on unassisted surgeries.
Data analysis confirmed that both external and endonasal DCR improved patients' quality of life.  Some authors have advocated the use of mitomycin-C, an alkylating agent that inhibits fibroblast proliferation to prevent wound closure in endonasal lacrimal surgery.  We did not consider the use of mitomycin-C necessary for prevention of the closure of the ostium.
A literature review shows a 75-99% success rate with Ex-DCR.  The success rates with EN-DCR without the use of a laser are 82-95%;  the success rate using the laser is slightly lower, 77-83%. , Our study has shown a success rate of 92% with EN-DCR.
Before the advent of the endoscope, DCR was always performed by the ophthalmic surgeon. Now-a-days, with the advancement of the nasal endoscope and more and more familiarity of otorhinolaryngologist surgeons with endoscopic anatomy of the nose, most of the EN-DCRs, at least in India, are performed by otorhinolaryngologist surgeons. This finding could be partly explained by the fact that EN-DCR surgery is not part of the traditional surgical training curriculum for oculoplastic fellowship trainees, and acquiring the skills to perform the procedure requires further sub-specialist training, with a steep learning curve. Besides, expensive armamentarium and satisfaction with the success rate of Ex-DCR are also deciding factors against EN-DCR.
| Conclusion|| |
We conclude that EN-DCR improves patients' quality of life and ocular symptomatology on a par with Ex-DCR. Treatment options should always be discussed with patients so that they can make well-informed decisions. The endonasal approach carries certain advantages, e.g., regarding facial scarring and postoperative discomfort and most importantly offers a high chance of symptomatic success. The learning curve of EN-DCR is steep and requires thorough knowledge of nasal anatomy so it will be of benefit to start performing it together with an otorhinolaryngologist surgeon who has expertise in endonasal surgeries. There will still be cases where a joint procedure is preferred such as those with grossly distorted anatomy from severe septal deviation, injury, radiation, or previous sinus surgery. An oculoplasty surgeon should learn to perform the EN-DCR to keep up with the times.
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[Figure 1], [Figure 2], [Figure 3]