We evaluated the effect of silicone stent use during endoscopic dacryocystorhinostomy on postoperative morbidities in comparison with versus without a silicone stent. Two authors independently searched six databases (PubMed, Embase, Scopus, the Web of Science, the Cochrane library, and Google Scholar) from inception of article collection to July 2017. The analysis included prospective randomized studies that compared intraoperative silicone stent insertion (silicone group) with no application of a silicone stent (control group), in which the outcomes of interest were success rate (lacrimal passage patent check with syringing, symptom relief, or endoscopic confirmation of fluorescein dye from the opening of Hasner’s valve) and morbidities (e.g., postoperative bleeding, rhinostomy closure, granulation tissue, synechia, and eyelid problems) after certain follow-up periods (over 10 weeks). Nine studies involving a total of 587 participants were included. Functional success rates tended to be higher in the silicone group than in the control, but there was no statistically significant difference in success rates (odds ratio, 1.45; 95% confidence interval, 0.77 to 2.73). According to the surgical type such as mucosal removal and mucosal flap surgery, the results from types didn’t demonstrate any significant effect, but the mucosal flap technique seemed to be more beneficial. Regarding postoperative morbidities, although the outcomes of the groups did not present any statistically significant difference, eyelid problems and postoperative bleeding tended to occur more frequently in the silicone group, but rhinostomy closure tended to occur more frequently in the control group. Success and morbidity rates showed no difference between the silicone stent group and control group in the meta-analysis. However, additional analyses revealed that the success rate of endonasal dacryocystorhinostomy using silicone intubation with mucosal flap has shown an improving trend, and morbidities such as granulation and synechia showed decreasing trends compared with the group without silicone intubation.
Dacryocystorhinostomy (DCR) is performed to secure drainage passage between the lacrimal sac and nasal cavity for treating nasolacrimal duct obstruction (NLDO) or stenosis [
However, the introduction of endoscopes with high-resolution led to the performance of endoscopic endonasal (En)-DCR. Many clinicians have advocated this surgical procedure for its several advantages, including no facial scarring, minimal blood loss, preservation of the medial canthal ligament, short operative time, and shortened hospitalization stay compared with Ex-DCR, as well as simultaneous correction of the most common causes of En-DCR failure, such as adhesions, deviated nasal septum, hypertrophic turbinates, or infected ethmoid sinuses [
However, the evidence in the existing report is not sufficient to conclude the role of silicone stenting during En-DCR fully [
A search of clinical studies was performed in PubMed, Embase, Scopus, the Web of Science, the Cochrane library, and Google Scholar up to a cutoff date of July 2017. The terms for searching followed: “endoscopy,” “dacryocystorhinostomy,” “silicone intubation,” “stent,” “nasolacrimal duct obstruction,” “dacryocystitis,” “success,” and “morbidity.” Only literatures published in English were selected. Not to miss any relevant reports, the reference lists were checked within the identified studies.
Two literature reviewers independently screened titles and abstracts for all candidate studies, and studies unrelated to intraoperative insertion of silicone stents during En-DCR were excluded. The entire text of a potentially relevant study was reviewed if inclusion of that study could not be decided based on the abstract solely.
Randomized controlled clinical trials that satisfy the following criteria were the objects of review: comparison of the success rates (subjective or objective assessments) and postoperative morbidities of patients received En-DCR with versus without a silicone stent. Studies were excluded if the patients had undergoing previous lacrimal surgery, had a history of trauma to the nasal or ocular region, or had experienced presaccal obstruction and the paranasal sinus malignancies, or if it was a duplicate report. Additionally, reports were not included if the clinical outcomes were reported without clear quantifiable data, or if the calculation results disagree with the appropriate data from the published reports. The searching strategy utilized for verifying the appropriate studies for the meta-analysis is summarized in
Data extraction was performed with standardized forms and independently checked by two reviewers (DHK, SHH). Outcome results of the analysis included success rate [
We extracted data about the number of En-DCR patients, the rates of success, postoperative bleeding, rhinostomy closure, granulation tissue, synechia, and eyelid problems, and
The statistical software R ver. 3.3.0 (The R Foundation, Vienna, Austria) was used to perform a meta-analysis of the selected studies. The “metafor” package for the effective measurements was utilized as the library in the R software. Odds ratios (ORs) were calculated based on an outcome incidence analysis. An OR is a measure of association between a silicon stent insertion and outcomes (success or postoperative morbidities). The OR represents the odds that an outcome will occur given a silicon stent insertion, compared to the odds of the outcome occurring in the absence of that treatment. In the meaning of values of, the value of OR is the same as “1,” which means that treatment does not affect odds of outcome. If the value is larger than 1, the treatment could be associated with higher odds of outcome. By contrast, if the value is smaller than 1, the treatment could be associated with lower odds of outcome. Heterogeneity was calculated with the I2 test, which describes the rate of variation across studies because of heterogeneity rather than probabilistic chance. The measure ranged from 0 (no heterogeneity) to 100 (maximum heterogeneity). All results were reported with a 95% confidence intervals (CI), and all
In total, nine studies involving 587 patients were included in the meta-analysis. Study characteristics and the bias assessment results are described in
The results of nine studies with related to success rate between silicone stent and control groups are summarized in
In this measurement, there were two different types of surgery such as mucosal removal and mucosal flap surgery, which could show the surgical results differently. Therefore, we performed the subgroup analysis according to the surgical type. The results from two different surgical types didn’t demonstrate any significant effect, but the mucosal sparing surgery (OR, 2.40; 95% CI, 0.88 to 6.53) and flap technique seemed to be more beneficially effective than mucosal removal surgery (OR, 0.85; 95% CI, 0.34 to 2.11) when it came to the surgical success (
The results of two to four studies with respect to postoperative morbidities in the silicone tube versus control groups are included. There was no significant inter-study heterogeneity (I2=0%) or publication bias (
However, silicone stenting showed a tendency to increase the rates of postoperative bleeding and eyelid problems compared with the control group. Additionally, silicone stenting tended to delay rhinostomy closure compared with the control group. The subgroup analysis according to the surgical type could not be performed, because there were a small number of the included studies in the individual results.
Sensitivity analyses were conducted to assess the difference between the pooled estimates of success rate and postoperative morbidities by repeating the analyses while omitting a different study each time. The final results were consistent with those above.
The surgical success was defined with either patent lacrimal passage on syringing, symptom improvement, or fluorescein dye in the DCR opening on nasal endoscopy [
In consideration of the maintenance of rhinostomy site, many surgeons have thought that placing stents or tube simultaneously during endoscopic DCR would be the gold standard procedure and has been performed accordingly [
In a previous meta-analysis regarding silicone tube intubation in DCR [
Nevertheless, from the surgical methods point of view, there were two distinctive methods to treat rhinostomy site in the nasal mucosa after lacrimal bone removal. Mucosal flap technique was usually performed with incision of the lacrimal sac and marsupialization with anterior and posterior flaps [
Eyelid problems such as swelling and postoperative bleeding tended to decrease relatively in the silicone stent group compared with control group despite statistical insignificance. These complications usually occur due to the trauma during probe tubing procedure, but they occurred temporarily for the most part and recovered after conservative care, having little effect on the surgical success rate. However, these problems could cause the dissatisfaction of both patients and surgeons. Previously, Unlu et al. [
This study has several limitations. The meta-analysis included only nine randomized, controlled, prospective studies. Thus, the sample size was small. The timing of tube removal, follow-up interval, and measurement indices were not fully consistent across the studies. These factors may have caused bias. Considering these limitations, a large-sample, randomized, controlled clinical study should be performed to provide further evidence on the efficacy of silicone intubation in En-DCR. Additionally, this analysis is performed based on the statistical measurements of the figure in the articles. So, external factors such as patient characteristics or demographic factors, surgeon skill, postoperative care, facility capacity could not be reflected in the analysis, which could be the inevitable limitation.
In conclusion, the success and postoperative morbidity rates showed no differences between the silicone stent and control groups in this meta-analysis. However, an additional meta-analysis revealed that the success rate of En-DCR using silicone intubation with mucosal flap has shown an improving trend. Consequently, surgeons need to perform the silicone intubation during En-DCR with simultaneously mucosal flap with careful consideration.
▪ The success and postoperative morbidity rates showed no differences between the silicone stent and control groups.
▪ The success rate of endoscopic endonasal dacryocystorhinostomy using silicone intubation has shown an improving trend recently.
▪ The rates of morbidities such as granulation and synechia have shown decreasing trends in the endoscopic endonasal dacryocystorhinostomy with silicone cases.
No potential conflict of interest relevant to this article was reported.
This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIP, MSIT) (2017R1D1A1B03027903, 2018M3A9E8020856), the Korea Health Industry Development Institute funded by the Ministry of Health and Welfare (HI14C3228, HI15C0133), Institute for Information & communications Technology Promotion (IITP) grant funded by the Korea government (MSIP) (No. 2017-0-00953), the Institute of Clinical Medicine Research of Bucheon St. Mary’s Hospital Research Fund (2018), and a grant of the ENT Fund of the Catholic University of Korea made in the program year 2017 and 2018.
Flowchart of the study selection.
Comparison of success rates between the silicone stent and control groups. Odds ratios (ORs) for success rate (A) and subgroups analysis according to the surgical type such as mucosal removal and flap surgery (B). Total, number of participants per group; CI, confidence interval.
Sensitivity analysis of success rates between the silicone stent and control groups. OR, odds ratio; CI confidence interval.
Comparison of postoperative morbidity rates between the silicone stent and control groups. Odds ratios (ORs) for the incidence of postoperative bleeding (A), eyelid problems (B), rhinostomy closure (C), granulation tissue (D), and synechia (E). Total, number of participants per group; CI, confidence interval
Summary of studies included in the meta-analysis
First author (year)/operation type | No. of patients in each group | Level of evidence | Surgical procedure/measure analyzed | Judgment of risk of bias |
---|---|---|---|---|
Kakkar (2008) [ |
Silicon (20) vs. control (20) | Level I (randomized controlled prospective study) | Removal lacrimal sac mucosa/success rate, postoperative morbidities (postoperative bleeding and rhinostomy closure) | Unclear |
Smirnov (2008) [ |
Silicon (23) vs. control (23) | Level I (randomized controlled prospective study) | Removal lacrimal sac mucosa/success rate, postoperative morbidities (postoperative bleeding) | Unclear |
Unlu (2009) [ |
Silicon (19) vs. control (19) | Level I (randomized controlled prospective study) | Removal lacrimal sac mucosa/success rate, postoperative morbidities (eyelid problem, granulation tissue) | High |
Al-Qahtani (2012) [ |
Silicon (92) vs. control (81) | Level I (randomized controlled prospective study) | Flap surgery/success rate | High |
Chong (2013) [ |
Silicon (63) vs. control (65) | Level I (randomized controlled prospective study) | Flap surgery/success rate, postoperative morbidities (granulation tissue) | low |
Shashidhar (2014) [ |
Silicon (32) vs. control (30) | Level I (randomized controlled prospective study) | Not specified/success rate, postoperative morbidities (eyelid problem, granulation tissue, and synechia) | High |
Reddy (2015) [ |
Silicon (10) vs. control (10) | Level I (randomized controlled prospective study) | Removal lacrimal sac mucosa/success rate, postoperative morbidities (synechia) | High |
Ahmad (2016) [ |
Silicon (15) vs. control (15) | Level I (randomized controlled prospective study) | Flap surgery/success rate, postoperative morbidities (postoperative bleeding) | Unclear |
Rao (2016) [ |
Silicon (20) vs. control (20) | Level I (randomized controlled prospective study) | Removal lacrimal sac mucosa/success rate, postoperative morbidities (postoperative bleeding, rhinostomy closure, and synechia) | High |