Prospective randomised comparison of external dacryocystorhinostomy with and without silicone intubation: considerations of power

One-week intubation in external dacryocystorhinostomy- a report on long-term outcome

PURPOSE

The role of silicone stent intubation in dacryocystorhinostomy (DCR) is not clear, and conclusions presented in the literature are contradictory both regarding if intubation should be recommended and if so, the appropriate duration of intubation. This paper reports on the long-term outcome of a comparatively short duration of silicone stent intubation, one week, and discusses the possibility of an optimal duration of intubation where the benefit of the silicone stent is utilized but with minimal risk of complications.

METHODS

A total of 70 cases of DCR were followed in 67 patients for four years in a descriptive case series of uncomplicated external DCR with one-week silicone stent intubation. Pre- and perioperative findings, complications, and the need for additional surgery were recorded. At end of follow-up, a questionnaire was sent to the patients asking them to grade the frequency of epiphoric problems. If graded often/constant, a follow-up visit was offered.

RESULTS

One patient received additional surgery during follow-up due to persistent epiphora caused by synechiae between the middle turbinate and lateral nasal wall. The response rate to the questionnaire was 88%, with 93% of the respondents reporting epiphora never/seldom. Four patients reported persistent problems: one declined further examination, the tear duct was anatomically patent in two, and one was referred to the ENT department due to inflamed nasal mucosa and extensive adhesions. The long-term functional or anatomical success rate was 97%.

CONCLUSIONS

This study shows that a high long-term success rate for uncomplicated DCR is possible with only one-week silicone stent intubation.

Comparing the Success Rate of Dacryocystorhinostomy With and Without Silicone Intubation: A Trial Sequential Analysis of Randomized Control Trials

A previous meta-analysis reported no benefit for silicone intubation during dacryocystorhinostomy. However, the power of this meta-analysis was 0.274. Therefore, the benefit of silicone intubation remains controversial. We undertook a cumulative meta-analysis to evaluate the success rate of dacryocystorhinostomy (DCR) with and without the use of a stent. Pubmed, EMBASE and the Cochrane Library were searched. Statistical power and trial sequential analyses were performed according to the result of the meta-analysis. Twelve randomized controlled trials involving 969 cases met the inclusion criteria. The success rates of DCR with and without intubation were significantly different (p = 0.006). The success rates of external DCR (EX-DCR) with and without intubation were also significantly different based on subgroup analysis (p = 0.002). The cumulative z-curves crossed the O’Brian-Fleming boundaries. There were no significant differences in the success rate in the endonasal endoscopic DCR (EN-DCR) subgroup or the occurrence of postoperative complications between the two groups based on the meta-analysis, and the z-curve did not intersect any trial sequential analysis boundaries. DCR with intubation achieved better results than DCR without intubation, especially in the EX-DCR subgroup. Differences in the success rate in the EN-DCR subgroup and postoperative complications between the two groups were underpowered to reach a conclusion.

Bicanalicular Silicone Stents in Endonasal Dacryocystorhinostomy: Results of a Randomized Clinical Trial

PURPOSE

To assess whether the use of silicone lacrimal stents affects the long-term success of endonasal dacryocystorhinostomy (EN-DCR).

DESIGN

Prospective, randomized, controlled, interventional trial.

PARTICIPANTS

The subjects were adult patients older than 16 years undergoing primary EN-DCR for nasolacrimal duct obstruction who gave fully informed consent and who had no lid malpositions or canalicular pathology. In cases with bilateral surgery, only the right eyes were studied. Participants were randomized to receive stents (control group) or not (study group).

METHODS

Standardized nonendoscopic EN-DCR was performed by the senior author in all cases. When the ostium was completed, the randomization code was revealed as to whether a lacrimal stent was placed or not. Follow-up assessments were made at 3, 6, 9, and 12 months. Stents were removed at 3 months.

MAIN OUTCOME MEASURES

The primary end point was symptoms of epiphora at 12 months, reported to the surgical booking clerk as (a) resolved, (b) significantly improved, (c) partially improved, or (d) no change or worse. The secondary end point was anatomic patency based on nasolacrimal syringing and categorized as (a) fully patent, minimal, or no reflux; (b) >50% patent but some reflux; (c) some patency but >50% reflux; or (d) nonpatent, 100% reflux. Complete success was defined as having resolved or significantly improved symptoms of watering and minimal or no reflux on nasolacrimal syringing. Partial success was defined as symptoms partially improved with a combination of patency and reflux on syringing. Failure was categorized as no change or worse symptoms of watering and 50% to 100% reflux on syringing.

RESULTS

A total of 300 patients completed 12 months of follow-up. A total of 152 patients received tubes, and 148 patients did not. Overall success both subjectively and objectively was 94.7% in the stented group and 87.8% in the nonstented group (P = 0.034, Pearson chi-square 1-tailed test). The most common complications of stents included canalicular cheese-wiring and tube prolapse in approximately 4% each.

CONCLUSIONS

There is a statistically significantly higher success rate in EN-DCR surgery with tubes compared with no tubes. The failure rate in this study was more than twice as high when tubes were not used (12.2% vs. 5.3%).

Randomized trial on silicone intubation in endoscopic mechanical dacryocystorhinostomy (SEND) for primary nasolacrimal duct obstruction

PURPOSE

To study the effect of bicanalicular silicone intubation on endonasal endoscopic mechanical dacryocystorhinostomy (EEM-DCR) for primary acquired nasolacrimal duct obstruction (PANDO).

DESIGN

Randomized clinical trial.

PARTICIPANTS

A total of 120 consecutive adults (103 females) with a presenting age of 64 ± 13.7 years (range, 39-92 years) underwent EEM-DCR for PANDO from November 2005 to May 2009 in a lacrimal referral center.

METHODS

The EEM-DCR was performed by 2 lacrimal surgeons using standard techniques. Patients were randomly assigned to receive or not receive bicanalicular silicone intubation for 8 weeks. No antimetabolite was used. All patients received a course of oral antibiotics during nonabsorbable nasal packing for flaps tamponade, which was removed at the first postoperative visit. Patients were assessed at 1, 3, 6, 12, 26, and 52 weeks after the operation.

MAIN OUTCOME MEASURES

Surgical success was defined by symptomatic relief of epiphora, reestablishment of nasolacrimal drainage confirmed by irrigation by 1 masked observer, and positive functional endoscopic dye test by the operative surgeon at 12 months postoperatively. Intraoperative and postoperative complications were recorded.

RESULTS

A total of 118 of the 120 randomized cases completed 12 months of follow-up. Two patients died of unrelated medical illnesses during follow-up. At 12 months postoperatively, there was no statistical difference in the success rate between patients with (96.3%) and without (95.3%) intubation (P=0.79). The odds ratio of failure without silicone intubation was 1.28 (95% confidence interval, 0.21-7.95). There was no difference in the incidence (P=0.97) or the time to develop (P=0.12) granulation tissue between the 2 groups. No significant difference was found between successful and failed cases in terms of age (P=0.21), sex (P=0.37), laterality (P=0.46), mode of anesthesia (P=0.14), surgeon (P=0.26), use of stent (P=0.79), or presence of granulation tissue postoperatively (P=0.39).

CONCLUSIONS

The current study design provided 90% statistical power to detect more than 21% difference in surgical outcome, and no such difference was found whether intubation was used or not used in EEM-DCR for PANDO at the 12-month follow-up.

FINANCIAL DISCLOSURE(S)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

A meta-analysis of primary dacryocystorhinostomy with and without silicone intubation

OBJECTIVE

To examine possible differences in success rates of primary dacryocystorhinostomy (DCR) with and without silicone intubation, and to find out whether the use of silicone tubes is beneficial.

DESIGN

A literature search was conducted in the PubMed, EMBASE, and Cochrane Controlled Trials Register to identify potentially relevant controlled trials.

METHODS

Language was restricted to English. The surgical techniques were categorized into external DCR (EX-DCR), endonasal laser-assisted DCR (LA-DCR), and nonlaser endoscopic endonasal DCR techniques (EN-DCR). The main outcome measure was success rates after DCR-with and DCR-without silicone intubation. The statistical analysis was carried out using a RevMan 5.0 software.

RESULTS

Of 188 retrieved trials from the electronic database, 9 trials (5 randomized controlled trials and 4 cohort studies) involving 514 cases met our inclusion criteria. There was no statistically significant heterogeneity between the studies. The pooled risk ratio was 0.99, with a 95% confidence interval (0.91-1.08). There was no significant difference in the success rates between the DCR with and without silicone intubation (p = 0.81). Sensitivity analysis and subgroups analyses suggested that the result was comparatively reliable.

CONCLUSIONS

Based on this meta-analysis that included 5 randomized controlled trials and 4 cohort studies, no benefit was found for silicone tube intubation in primary DCR. Further well-organized, prospective, randomized studies involving larger patient numbers are required.

Postoperative infection rate after dacryocystorhinostomy without the use of systemic antibiotic prophylaxis

PURPOSE

To evaluate the postoperative infection rate after external dacryocystorhinostomy (DCR) without routine systemic antibiotic prophylaxis.

METHODS

Retrospective review of case notes, including eye casualty attendances, of 77 patients undergoing 82 consecutive external DCR procedures between 22 December 2006 and 31st December 2009 performed by one of the authors (O. M. Durrani) at a single centre (The Birmingham and Midland Eye Centre, United Kingdom). Patients were given topical Maxitrol eye drops (dexamethasone 0.1%, neomycin 3.5 mg and polymixin B sulphate 10,000 units) three times a day for 1 week postoperatively but no systemic antibiotics.

RESULTS

Postoperative infection occurred in one of 82 cases (1.2%, 95% confidence interval 0.03-6.6%). The one case of infection consisted of superficial wound infection only and was managed with oral antibiotics and resolved with a successful outcome. Thirteen out of 87 cases were performed in patients with recurrent dacryocystitis or mucocoeles; none of these cases were complicated by postoperative infection.

CONCLUSIONS

Postoperative infection after external DCR without the use of systemic antibiotics is uncommon. Assuming that oral antibiotics are 80% effective at treating postoperative infection, for routine prophylaxis, the number needed to treat to prevent one infection would be 104. Taking the upper confidence limit of 6.6%, the lower limit of the number needed to treat would be 19. The one case of infection was treated successfully with oral antibiotics and resolved with a successful outcome. These results suggest that the routine use of systemic antibiotic prophylaxis in external DCR may not be justified.