External dacryocystorhinostomy conventional surgery versus Pawar implant: A comparative study.

Purpose: External dacryocystorhinostomy (DCR) surgeries are cost-effective with excellent success rates. The present study was designed to compare the safety and efficacy of conventional external DCR versus external DCR using Pawar silicone implant in chronic dacryocystitis.
Methods: This is a prospective, comparative, interventional case series over a period of 18 months with patients managed by external DCR surgery with and without Pawar implant. Institutional review board approval was obtained before the study. The success of the surgery was objectively measured by sac patency on syringing at the last follow up.
Results: A total of 65 patients with chronic dacryocystitis were included in the study. The mean age of patients in the series was 41.43 years (median, 41 years; range, 12 years-60 years). All patients presented with epiphora (100%) and underwent external DCR and were chosen for conventional surgery (n = 33, 51%, group 1) or Pawar silicone implant surgery (n = 32, 49%, group 2) on a random basis. The mean duration of the surgery from the time of skin incision to skin closure for group 1 was 27.7 minutes (median, 26 minutes; range, 21-30 minutes) while in group 2, it was 75.5 minutes (median, 75 minutes; range, 60-88 minutes), which was statistically significant (P < 0.01). The success rate of the procedure done in group 1 was 90% which increased to 97% after the management of failed cases as compared to the success rate in group 2 of 91% and 94%, before and after the management of failed cases, respectively.
Conclusion: External DCR using Pawar implant is a safe surgery which is faster than conventional external DCR with almost equal success rates between both the procedures.

Dacryocystorhinostomy (DCR) has undergone several modifications since its first description by Toti in 1904.[1] An external DCR provides a highly predictable result as the meticulous dissection is performed under direct visualization. A successful DCR necessitates the creation of a permanent, mucosa-lined ostium. External DCR in adults is known to yield a success rate of up to 95%.[23456789] In a report by Saiju et al., the failure rate of external DCR without an intubation was noted to be about 9%.[7] Ostium-related complications are considered to be the most common cause of failure of DCR.[10111213] Some of these causes include mucosal migration over the ostium, cicatricial contraction of the ostium, and exuberant healing around the ostium leading to a nonpatent conduit.[10111213] Pawar intracystic implant was intended with an aim to maintain a long-term patency of the ostium and promote normal healing of the flap as well as the ostium.[14] To the best of our knowledge, there is no study published on the comparison of conventional DCR and DCR with Pawar implant on Indian subjects. The present study was designed to compare the safety and efficacy of external DCR by the conventional technique versus DCR with Pawar intracystic silicone implant in chronic dacryocystitis.

Methods

This is a prospective, comparative, interventional study done at Regional Institute of Ophthalmology, Institute of Medical Sciences, BHU, Varanasi from October 2015 to March 2017. Approval from the Institutional Ethical Committee was obtained. A total of 65 patients with chronic dacryocystitis were chosen and randomly divided into two operative groups. Group 1 underwent external DCR using Pawar intracystic implant and group 2 underwent conventional external DCR. All patients were explained about the risks and complications of the surgery and an informed consent was obtained from all patients. Every patient underwent adequate preoperative evaluation and investigations. Patients with previous history of failed DCR, dacryocystectomy, canalicular block, nasal pathology, and neoplasms of sac and adnexa were excluded from the study.

Demographic data included age at presentation and gender. General ocular features including the eye laterality and eye involved. In all patients, nasolacrimal duct (NLD) obstruction was confirmed by syringing. All the surgeries were performed by single surgeon under local/general anesthesia. Treatment data included duration of the surgery (in minutes), any complications, and the success of the procedure. The success was defined objectively by sac patency on syringing.

Conventional external DCR was performed under local/general anesthesia depending on the patient's age.[514] The skin incision was made in a curvilinear pattern measuring 10–12 mm along the anterior lacrimal crest. Further dissection through the subcutaneous tissue was performed with a tenotomy scissors, splitting the soft tissue to reach the periosteum of the anterior lacrimal crest. The anterior horn of the medial canthal ligament was divided. Using a periosteal elevator, blunt dissection was done down to the periosteum of the inferior orbital rim just anterior to the lacrimal fossa. The periosteal elevator was then used to lift the periosteum off the bone, thus enabling visualization of the lacrimal sac fossa.

A small osteotomy was initiated at the junction of the lamina papyracea and the lacrimal bone using the periosteal elevator. Kerrison rongeurs were used to enlarge the ostium. The ostium was enlarged anteriorly till the nasal mucosa is not separable from the bone, inferiorly till the level of the NLD, and superiorly 2 mm above the level of the common internal punctum. Under good visualization, a horizontal slit was made from the sac–duct junction up to the fundus of the sac, with two perpendicular vertical slits on its either end. Nasal mucosal flaps were fashioned with two vertical slits placed on either end of the horizontal slit, and both the remnant posterior lacrimal and nasal mucosal flaps excised. The two anterior flaps were sutured with the nasal mucosal flap overlapping the sac flap with 6-0 vicryl suture. Orbicularis was closed with 6-0 vicryl, followed by skin closure with 6-0 silk suture. Intracanalicular irrigation was then performed to demonstrate free flow into the nasal cavity without any regurgitation.

Pawar implant, packed and sterilized with gamma rays, is made of medical-grade silicone elastomer which ensures high tissue compatibility and minimal thrombogenicity [Fig. 1].[1415] It has a length of 12–17 mm with an external diameter of 3–4 mm and internal diameter of 2.5–3.5 mm. There are holes at the proximal and distal ends that act as drainage channels. In external DCR using Pawar implant, the anesthesia and surgical procedure are the same as that for a conventional external DCR, except for a smaller skin incision (5–6 mm) and smaller bony ostium. The medial canthal ligament is also not divided in implant DCR. For the implant, initially a perforator is used to make a small entry through the posterior wall and nasal mucosa, and then the sterilized implant is mounted on an introducer and placed in the lacrimal sac. The wider portion of the implant lies within the sac, fixated with a 6-0 vicryl suture. The narrow end extends a little beyond the bony ostium [Fig. 2a–d]. The anastomosis between the lacrimal sac and nasal mucosa is then made over the implant.

Figure 1

Pawar intracystic implant with a proximal wide collar to help in anchorage around the lacrimal sac and a distal tune that rests at the ostium

Figure 2

Technique of implant DCR. (a) A small skin incision and meticulous dissection to expose the lacrimal sac. (b) Pawar implant being placed within the sac using an introducer. (c) After anchoring the implant in the sac, anterior sac flap is sutured to the anterior nasal mucosal flap. (d) Skin incision after subcutaneous tissue approximation

Following DCR, all patients received oral and topical antibiotics, antiinflammatory, and nasal decongestants in the postoperative management. Each patient was followed up for at least 6 months, and syringing was repeated on postoperative day 1, followed by 1 week, 1 month, 3 months, and 6 months.

Results

Of the 65 patients enrolled in the study, 33 patients (51%) belonged to group 1 and 32 patients (49%) belonged to group 2. Demographic features are shown in Table 1. The mean patient age in groups 1 and 2 was 40.42 years (Median 40 years; range, 19–60 years) and 42.46 years (Median 41.5 years; range, 21–59 years), respectively. Females were in majority, with a female to male ratio of 3:2.

Table 1

Conventional DCR vs Implant DCR: Demographic Features

Features	Group 1 (n=33, %)	Group 2 (n=32, %)
Age, years
Mean (median, range)	40.4 (40, 19-60)	42.4(41.5,21-59)
Gender
Male	13 (39)	12 (38)
Female	20 (61)	20 (62)
Laterality
Unilateral	33 (100)	31 (100)
Bilateral	0 (0)	0 (0)
Eye involved
Right	15 (45)	14 (44)
Left	18 (55)	18 (56)

Table 2 elaborates the surgery details of both the groups. The mean size of the skin incision in group 1 was 5.5 mm (median, 5 mm; range, 5–6 mm) and in group 2 was 12 mm (median, 12 mm; range, 10–12 mm). Medial canthal ligament division was necessary in all patients in group 2 (n = 32, 100%) as compared to none (n = 0, 0%) in group 1. The mean diameter of the ostium created in group 1 was 3 mm (median, 3 mm; range, 3–4 mm) and in group 2 was 13 mm (median, 12 mm; range, 12–14 mm). Intraoperative bleeding was lesser in group 1 patients. The mean length of the surgery, calculated as the time interval between the placement of the skin incision to skin closure, required for group 1 cases was 27.7 min (median, 26 min; range, 21–30 min) and in group 2 was 75.5 min (median, 75 min; range, 60–88 min), which was statistically significant (P < 0.01). Also, while only two patients (6%) in group 1 had bleed from the nasal mucosa, 12 patients (37%) had bleed from the nasal mucosa among group 2 patients. In addition, of the 32 group 2 patients, 3 (9%) had bleed from the angular vein and 5 (15%) had disruption of the nasal mucosa. In group 1, neither of the events occurred in any patients. In addition, nasal packing was not required in any of the group 1 patients postoperatively.

Table 2

Conventional DCR vs Implant DCR: Surgical Procedure and Outcomes

Features	Group 1 (n=33, %)	Group 2 (n=32, %)
External DCR
With Pawar's implant	33 (100)	0 (0)
Without Pawars's implant	0 (0)	32 (100)
Size of the skin incision, mm
Mean (median, range)	5 (5, 5-6)	12 (12, 10-12)
Medial canthal ligament division
Yes	0 (0)	32 (100)
No	33 (100)	0 (0)
Diameter of the ostium, mm
Mean (median, range)	3 (3, 3-4)	13 (12, 12-14)
Duration of surgery, minutes
Mean (median, range)	27.7 (26, 21-30)	75.5 (75, 66-80)
Nasal packing
Yes	0 (0)	32 (100)
No	33 (100)	0 (0)
Intraoperative complications
Nasal mucosa bleed	12 (37)	2 (6)
Angular vein bleed	3 (9)	0 (0)
Nasal mucosa disruption	5 (15)	0 (0)
Duration of follow-up, months
Mean (median, range)	7.5 (7.5, 6-9)	7.4 (7.5, 6-9)
Lacrimal patency on syringing at 1 month	30 (90)	29 (91)
Early failure
Mucus plus formation	2 (6)	0 (0)
Granulation	1 (3)	2 (6)
Ostium phimosis	0 (0)	1 (3)
Lacrimal patency on syringing at 6 months	32 (97)	30 (94)

At 1-month follow-up, failure of the procedure (regurgitation on syringing) occurred in three patients, each in both the groups [Table 3]. In group 1, mucosal plug formation occurred in two patients which was managed with repeated syringing to reestablish the patency. In one patient, late sac infection and granulation tissue formation were noted, which were managed with systemic and topical antibiotics followed by tube implantation. Among group 2 patients, one patient required repeat DCR for ostium phimosis and two patients required tube implantation to manage the granulation tissue. At 6 months follow-up, the success rate of the procedures in group 1 increased from 90% at 1 month follow-up to 97%, whereas in group 2 it increased from 91 to 94%.

Table 3

Conventional DCR vs Implant DCR: Management of early failure

Group	Complication	Management	Immediate syringing	Syringing at 6-month follow-up
Group 1	Mucus plug formation	Repeated syringing	Patent	Patent
Group 1	Mucus plug formation	Repeated syringing	Patent	Patent
Group 1	Sac infection and granulation tissue	Antibiotics and tube implant	Patent	Patent
Group 2	Granulation tissue	Tube implant	Patent	Patent
Group 2	Granulation tissue	Tube implant	Patent	Patent
Group 2	Ostium phimosis	Re-DCR	Patent	Patent

Discussion

Acquired NLD obstruction is a common cause of epiphora and most frequently results from an acute or a chronic inflammation of the lacrimal drainage system leading to a nonpatent NLD. An NLD obstruction is bypassed in DCR by way of an anastomosis between the lacrimal sac and nasal mucosa, with or without the use of an implant. External DCR is a cost-effective surgery with high success rates and a short learning curve.[16] Implant DCR is an augmented DCR technique that helps maintain a long-term ostium patency and reduce the failure rates.[171819] In addition, an implant DCR overcomes the shortcomings of a conventional external DCR, which include a larger skin incision, bleeding, long operative times, and ostium phimosis.[17181920]

Pawar intracystic implant was described by Pawar in 1987.[14] The idea was to provide a smooth conduit for tear drainage without any long-term susceptibility to intrasac fibrosis or ostium phimosis. In a prospective study by Chaudhari et al., 30 patients underwent DCR with Pawar implant.[21] The technique used for the implant insertion was in accordance with the original description by Pawar.[1421] After identifying the anterior sac wall and making an incision over it, a perforator was used to make a hole through the posterior wall and nasal mucosa. The Pawar implant was then introduced into the hole using an introducer.[21] Of the 30 patients, six patients (20%) had ostium closure at 3 months follow-up.[21] In contrast, only 3 of our 33 patients (9%) had ostium closure at 6 months follow-up.

In our study, the success rate of the procedures done using Pawar implant was almost 97%, as compared to 90% in conventional DCR. The presence of a silicone tube not only guaranteed the long-term patency of the ostium but it is also possible that the silicone tube ensures a smoother healing process resulting in lower amount of scarring and lesser formation of exuberant granulation tissue. The study, however, has certain limitations. The success of the surgery was noted only in terms of objective assessment. A subjective relief of symptoms was not assessed. In addition, only syringing was done to ascertain the patency of the anastomosis. More sophisticated objective measures, including endoscopic assessment of the ostium, were not performed. Another limitation of the study is a shorter duration of follow-up as patients who remain symptom-free after DCR fail to follow-up in long term.

Conclusion

In conclusion, implant surgeries are safe, time-saving, and less traumatic than conventional DCR procedures with almost equal success rates between the two techniques. The smaller skin incision, the lack of need for nasal packing, shorter hospital stay, and early ambulation are obvious advantages in implant surgeries in the follow-up period. None of the patients in this series were noted to have implant extrusion. Pawar intracystic implant gives a highly predictable result with minimal complications, making it a better alternative for a conventional external DCR.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.