Use of Mitomycin C in Dacryocystorhinostomy: A Report by the American Academy of Ophthalmology

PURPOSE

To review the literature on the adjuvant use of mitomycin C (MMC) during dacryocystorhinostomy (DCR) in adults with primary nasolacrimal duct obstructions (NLDOs) to determine the efficacy in improving functional and anatomic outcomes with an acceptable level of risk.

METHODS

A literature search conducted in November 2020 and updated in November 2022 yielded 137 articles. Twenty-four articles met the inclusion criteria and were rated for level of evidence by the panel methodologist. Inclusion criteria required controlled studies on the effect of MMC on outcomes of external, endoscopic endonasal, or diode laser-assisted transcanalicular DCR in adults with primary acquired nasolacrimal obstruction with 6 months minimum follow-up and at least 10 participants.

RESULTS

Six of the 24 articles were rated level I evidence, 15 level II , and 3 level III. In primary external DCR, MMC significantly improved functional outcomes in 3 of 9 series. In primary endoscopic endonasal DCR, MMC significantly improved functional outcomes in 1 of 9 series. In revision endoscopic endonasal DCR, MMC significantly improved functional success in 1 of 3 series. The use of MMC did not improve outcomes statistically in any diode laser-assisted transcanalicular DCR studies. Concentrations of MMC ranged from 0.05 to 1 mg/ml, with 0.2 mg/ml used most frequently in 12 series, with duration of application ranging from 2 to 30 minutes. Ostium size was significantly larger in MMC groups than in control groups at 6 months after surgery in 4 of 5 reporting studies. However, these larger ostia did not confer higher functional success rates. Reporting of adverse events related to MMC were rare, with delayed cutaneous wound healing reported in 1 of 750 patients.

CONCLUSIONS

Intraoperative use of MMC in external and endoscopic endonasal DCR has been shown to improve functional and anatomic outcomes compared with controls in some series, but there is no agreement on the recommended concentration or application time for MMC in DCR. The data support that MMC use can result in a larger ostium size, decreased granulation tissue formation, and a decreased number of postoperative nasal debridements compared with controls, but this does not translate into improved functional success.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Recurrent epiphora after dacryocystorhinostomy surgery: Structural abnormalities identified with dacryocystography and long term outcomes of revision surgery : Success rates of further surgery following failed dacryocystorhinostomy surgery

Background

To investigate the aetiopathology of recurrent epiphora or stickiness after dacryocystorhinostomy (DCR) surgery, identifiable on dacryocystography (DCG), and to assess the success rates of secondary corrective surgeries.

Methods

Consecutive post-DCR DCG images from patients with recurrent symptoms were reviewed between 2012 and 2015.

Results

One hundred fifty-nine eyes of 137 patients were evaluated. Fifty-eight DCGs showed normal postoperative findings, 4 an upper/lower canalicular block, 13 a common canalicular block, 31 a completely closed anastomosis, 50 a narrow anastomosis, and 3 an anastomosis draining into a nasal sinus.

The most successful corrective procedures for each failure category were: Lester Jones Tube (LJT) for a normal post-operative DCG (17/18 success), Sisler trephination with tubes for upper/lower canalicular block (1/2 success), redo-DCR with tube for common canalicular blockage (5/6 success), redo-DCR +/− tube for completely closed anastomosis (12/16 success), LJT followed by redo-DCR +/− tube for narrow surgical anastomosis (1/1 and 17/27 success respectively), and redo-external-DCR with tube for anastomosis into a nasal sinus (1/1 success). Redo-DCR was ineffective in patients who had good post-DCR anatomical patency (22% success).

Conclusion

This is the first study to report success rates of redo-DCR surgery according to anatomical findings confirmed by DCG. The outcome flow diagram help clinicians recommend procedures that are most likely to be successful for their patient’s specific anatomical abnormality. It also provides a visual tool for the shared decision-making process. Notably, symptomatic patients with a normal DCG post DCR are unlikely to benefit from redo-DCR, with a LJT being the recommended next step.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12886-021-01869-8.

Long-term Outcomes for Revision Endoscopic Dacryocystorhinostomy-The Effect of the Primary Approach

OBJECTIVES/HYPOTHESIS

Revision endoscopic dacryocystorhinostomy (END-DCR) is the preferred approach for failed primary surgeries, yet quality data on long-term outcomes are lacking. This study aimed to evaluate three aspects of revision END-DCR: 5-year success rates, patient satisfaction, and the primary surgical approach's possible impact on revision.

METHODS

This retrospective study included all revision END-DCRs conducted at Kaplan Medical Center between the years 2002 and 2015. For long-term follow-up analysis, two subgroups of first and second revision END-DCRs with a minimum of documented 5-year follow-up after surgery were defined. Data were analyzed according to the primary surgical approach. Surgical success was defined by either anatomical (observed patent lacrimal flow) or functional (symptoms cessation) success. Patient satisfaction was measured by a questionnaire.

RESULTS

After exclusions, a total of 45 eyes from 38 patients who underwent revision END-DCR surgeries were included in the study. The yearly success rates from immediate to 5 years following the first revision were 93.3%, 75.5%, 71.1%, 68.9%, 68.9%, and 68.9% for the entire cohort, respectively. Immediate and 5-year success rates following the second revision were 88.8% and 77.8%, respectively. Primary END-DCR showed favorable 5-year success rates and patient satisfaction over primary external dacryocystorhinostomy (EXT-DCR) in both first and second revisions, but this did not reach significance.

CONCLUSIONS

Revision END-DCR carries an excellent short-term success rate, which decreases mainly throughout the first 2 years following surgery. Postoperative follow-up should be maintained within this timeframe. Revision END-DCR following either primary endoscopic or EXT-DCR produces comparable surgical outcomes and patient-reported satisfaction.

LEVEL OF EVIDENCE

3b Laryngoscope, 131:E682-E688, 2021.

Antimetabolites as an adjunct to dacryocystorhinostomy for nasolacrimal duct obstruction

BACKGROUND

Nasolacrimal duct obstruction (NLDO) is a condition that results in the overflow of tears (epiphora) or infection of the nasolacrimal sac (dacryocystitis). The etiology of acquired NLDO is multifactorial and is not fully understood. Dacryocystorhinostomy (DCR) is the surgical correction of NLDO, which aims to establish a new drainage pathway between the lacrimal sac and the nose. The success of DCR is variable; the most common cause of failure is fibrosis and stenosis of the surgical ostium. Antimetabolites such as mitomycin-C (MMC) and 5-fluorouracil (5-FU) have been shown to be safe and effective in reducing fibrosis and improving clinical outcomes in other ophthalmic surgery settings (e.g. glaucoma and cornea surgery). Application of antimetabolites at the time of DCR has been studied, but the utility of these treatments remains uncertain.

OBJECTIVES

Primary objective: To determine if adjuvant treatment with antimetabolites improves functional success in the setting of DCR compared to DCR alone. Secondary objectives: To determine if anatomic success of DCR is increased with the use of antimetabolites, and if the surgical ostium is larger in participants treated with antimetabolites.

SEARCH METHODS

We searched the Cochrane Register for Controlled Trials (CENTRAL) (which contains the Cochrane Eye and Vision Trials Register) (2019, Issue 9), Ovid MEDLINE, Embase.com, PubMed, LILACS (Latin American and Caribbean Health Sciences Literature database), ClinicalTrials.gov, and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP). We did not use any date or language restrictions in the electronic searches. We last searched the electronic databases on 6 September 2019.

SELECTION CRITERIA

We only included randomized controlled trials. Eligible studies were those that compared the administration of antimetabolites of any dose and concentration versus placebo or another active treatment in participants with NLDO undergoing primary DCR and reoperation. We only included studies that had enrolled adults 18 years or older. We also included studies that used silicone intubation as part of the DCR procedure.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. Two review authors independently screened the search results, assessed risk of bias, and extracted data from the included studies using an electronic data collection form.

MAIN RESULTS

We included 31 studies in the review, of which 23 (1309 participants) provided data relating to our primary and secondary outcomes. Many of the 23 studies evaluated functional success, while others also assessed our secondary outcomes of anatomic success or ostium size, or both. Study characteristics Participant characteristics varied across studies, with the age of participants ranging from 30 to 70 years. Participants were predominantly women. These demographics correspond to those most frequently affected by nasolacrimal duct obstruction. Almost all of the studies utilized MMC as the antimetabolite, with only one using 5-FU. We assessed most trials as at unclear risk of bias for most domains. Conflicts of interest were not frequently reported, although the antimetabolites used are generic medications, and studies were not likely to be conducted for financial interest. Findings Twenty studies provided data on the primary outcome of functional success, of which 7 (356 participants) provided data at 6 months and 14 (909 participants) provided data beyond 6 months. At six months, the results showed no evidence of effect of antimetabolite on functional success (risk ratio (RR) 1.12, 95% confidence interval (CI) 0.98 to 1.29; low-certainty evidence). Beyond six months, the results favored the antimetabolite group (RR 1.15, 95% CI 1.07 to 1.25; moderate-certainty evidence). Fourteen studies reported data on the secondary outcome of anatomic success, of which 4 (306 participants) reported data at 6 months and 12 (831 participants) provided data beyond 6 months. Results at six months showed no evidence of effect of antimetabolite on anatomic success (RR 1.02, 95% CI 0.95 to 1.11; low-certainty evidence). Beyond six months, participants in the antimetabolite group were more likely to achieve anatomic success than those receiving DCR alone (RR 1.09, 95% CI 1.04 to 1.15; moderate-certainty evidence). At six months and beyond six months follow-up, two studies reported mean change in ostium size. We did not conduct meta-analysis for the various follow-up periods due to clinical, methodological, and statistical heterogeneity. However, point estimates from these studies at six months consistently favored participants in the antimetabolite group (low-certainty evidence). Beyond six months, while point estimates from one study favored participants in the antimetabolite group, estimates from another study showed no evidence of a difference between the two groups. The certainty of evidence at both time points was low. Adverse events Adverse events were rare. One study reported that one participant in the MMC group experienced delayed wound healing. Other studies reported no significant adverse events related to the application of antimetabolites.

AUTHORS' CONCLUSIONS

There is moderate-certainty evidence that application of antimetabolites at the time of DCR increases functional and anatomic success of DCR when patients are followed for more than six months after surgery, but no evidence of a difference at six months, low-certainty of evidence. There is low-certainty evidence that combining antimetabolite with DCR increases the size of the lacrimal ostium at six months. However, beyond six months, the evidence remain uncertain. Adverse effects of the application of antimetabolites were minimal.

Resolving Perplexity: Comparison of Endoscopic Dacryocystorhinostomy With and Without Stent

Endoscopic dacryocystorhinostomy (DCR) is an effective surgical procedure to treat nasolacrimal duct obstruction. This study was conducted with an aim of comparing the success rate between use of stent and without use of stent in endoscopic DCR. A prospective randomized study was conducted. Total 50 cases with signs of nasolacrimal duct blockage were included. The cases were randomly divided in two groups with 25 cases in each group. Group A cases underwent endoscopic DCR with stent and group B without stent. The follow up was till 12th week. Both subjective and objective outcomes were noted. By 12th week, only 8% cases had no relief of symptoms in group A while 92% cases of group A and all cases of group B had complete relief of symptoms. In objective outcome, by the 12th week, in group A 92% cases had full patency while in group B 100% cases had full patency. Overall complications in postoperative period were seen in 28% patients in group A and 12% patients in group B. In this study the surgical results of endoscopic DCR with or without stent came almost equal with no statistical difference in the success rate between stent group and non-stent group. Now that Endoscopic DCR without stent is equally effective and reduces cost, we recommend that the endoscopic DCR without stent should be preferred.

Comparing Outcomes of the Standard Technique of Endoscopic DCR with Its Modifications: A Retrospective Analysis

Objective

To compare the outcomes of various techniques of endoscopic dacryocystorhinostomy (DCR).

Study Design

Retrospective case record analysis.

Settings

Tertiary care referral center.

Subject and Methods

Retrospective analysis of case records was carried out pertaining to the period from January 1996 to September 2017 with respect to patients who had undergone endoscopic DCR with either the standard technique or one of its modifications. Case notes showing well-documented preoperative evaluation, operative details, postoperative assessment, and minimum 6-month follow-up were considered. The outcomes were measured on the basis of patients’ postoperative symptoms, clinical examination, and sac-syringing results.

Results

A total of 423 patients were included in the study. Of these, 169 underwent standard endoscopic DCR; 87, endoscopic DCR with stent; 19, endoscopic DCR with mitomycin C; 62, powered DCR; 29, laser-assisted DCR; and 57, balloon DCR. There was no statistically significant difference in success rates, recurrences, or complications of various techniques at 3 or 6 months. Mean operating time was lowest for balloon DCR (mean ± SD, 27.1 ± 3.1 minutes), followed by standard endoscopic DCR (38.2 ± 3.6 minutes; P = .001).

Conclusion

Standard endoscopic DCR and its more sophisticated modifications were equally effective and safe in managing distal nasolacrimal drainage obstruction. Balloon DCR, followed by standard endoscopic DCR, was significantly faster than other techniques.

Topical Mitomycin C Application Is Effective Even in Esophageal Strictures Resistant to Dilatation Therapy in Children

PURPOSE

Several treatment techniques may be used in the treatment of esophageal strictures. The purpose of this study was to present the effects of topical mitomycin C (TMC) as an useful adjunct to dilatation therapy in esophageal strictures.

MATERIALS AND METHODS

A retrospective analysis of patients who underwent TMC between February 2015 and July 2016 was performed. Dysphagia score, periodic dilatation index, and number of dilatations were compared before and after intervention to investigate the efficacy of TMC.

RESULTS

TMC was performed on 20 patients with a median age of 3.5 years (2 to 17 y). The diagnosis was corrosive esophageal strictures in 14 patients, anastomotic strictures in 5 patients, and congenital esophageal stricture in 1 patient. The length of the stricture was long in 10 patients (50%). The median dysphagia score decreased from 2 (1 to 3) to 0 (0 to 2) after application (P<0.001). The median number of dilatation sessions decreased from 5 (1 to 41) to 1 (0 to 11) after intervention (P<0.001). The median periodic dilatation index decreased from 1 (0.66 to 1.34) to 0 (0 to 1.33) after TMC (P<0.001). Regular esophageal dilatation was not necessary in 16 patients after application (80%). The length of the stricture did not affect the efficacy of TMC. The success of treatment was lower in patients with a long treatment period before TMC (>3 y) (50%). No complications were seen in a median follow-up period of 16 months (7 to 22 mo).

CONCLUSIONS

TMC application has a significant positive effect as an adjunct to dilatation therapy in most of the patients with different types of esophageal strictures. It should be performed as a safe and efficient treatment option even in patients who were resistant to dilatation therapy.

[Mitomycin C after endoscopic endonasal dacryocystorhinostomy]

Mitomycin-C (MMC) is the most frequently used agent for prevention of excessive scarring at the osteotomy site after endoscopic endonasal dacryocystorhinostomy (EEDCR), which, however, being applied during the final stage of the surgery, shows questionable effectiveness.

AIM

to evaluate the effectiveness of a new administration route of mitomycin C in EEDCR.

MATERIAL AND METHODS

The study included 86 patients (95 cases) in the age range of 62.3±9 years with primary acquired nasolacrimal duct obstruction. All patients underwent P.J. Wormald modification of EEDCR and were further divided into 2 groups. In group 1, MMC was injected into the nasal cavity and lacrimal sac mucosa, while in group 2 it was applied locally according to the standard procedure. To measure tissue concentrations of MMC, mucosal biopsies were taken in patients of Group 1. Systemic absorption of MMC was studied through blood samples in both groups. Clinical efficacy was assessed in 14±5 months after surgery.

RESULTS

immediately after injection, the average tissue concentration of mitomicyn C in patients of Group 1, was 390±10 µg/g and 30 minutes later - 120±20 µg/g. No mitomycin C was found in Day 1 tissue samples and in any of the blood samples. Positive clinical results were reported in 97.9% of cases from Group 1 and in 87.2% of cases from Group 2.

CONCLUSION

The method of injecting MMC during the final stage of EEDCR has proved clinically effective and safe and can be recommended for use in clinical practice.

Causes of unsatisfactory results of the use of mitomycin-C in endoscopic endonasal dacryocystorhinostomy

Purpose

To study the antifibrotic effectiveness of mitomycin-C in the tissues of the ostium site after it application for endonasal endoscopic dacryocystorhinostomy.

Material and methods

The study included 45 patients (48 cases) with primary obstruction of the nasolacrimal duct. All patients underwent endoscopic endonasal dacryocystorhinostomy (EEDCR). At the final stage of the operation, a swab with MMC was placed in the region of the formed ostium at a concentration of 0.2 mg/ml for 3 min. An ostium was not intubated. After that, biopsies of the mucous of the nasal cavity and lacrimal sac were performed to study the morphological changes that occur in the tissues overtime, as well as to calculate the concentration of the drug in the tissues.

Results

According to the chemical analysis, the concentration of MMC immediately after application was 0.626 ± 0.176 μg/g; after 30 min the concentration of the drug was reduced to 0.23 ± 0.06 μg/g; a day after the operation the drug was not found in the tissue samples. Morphological study established that the repair processes occurring in the mucosa of the nasal cavity and the lacrimal sac after EEDCR are similar to the reparative processes without the use of MMC. The effectiveness of surgical treatment: “positive results” - 77.1% of cases, “relapses” - 22.9% of cases.

Conclusions

Application of MMC for prevention of excessive scarring after EEDCR is impractical as it is not possible to achieve antifibrotic concentration of the drug at dacryocystorhinostomy ostium site using this method.

Mitomycin-C in dacryocystorhinostomy: From experimentation to implementation and the road ahead: A review

Dacryocystorhinostomy (DCR) is the procedure of choice in patients with epiphora due to primary acquired nasolacrimal duct obstruction. The evolution of surgical tools, fiber-optic endoscopes, effective anesthesia techniques, and the adjunct use of antimetabolites intraoperatively; namely mitomycin-C (MMC) have significantly contributed to the advancement of DCR surgery. MMC is a systemic chemotherapeutic agent derived from Streptomyces caespitosus that inhibits the synthesis of DNA, cellular RNA, and protein by inhibiting the synthesis of collagen by fibroblasts. Even the cellular changes in the human nasal mucosal fibroblasts induced by MMC at an ultrastructural level have been documented. There, however, seems to be a lack of consensus regarding MMC: The dosage, the route of delivery/application, the time of exposure and subsequently what role each of these variables plays in the final outcome of the surgery. In this review, an attempt is made to objectively examine all the evidence regarding the role of MMC in DCR. MMC appears to improve the success rate of DCR.

Treatment of Refractory Gastrointestinal Strictures With Mitomycin C: A Systematic Review

BACKGROUND AND AIMS

Refractory benign gastrointestinal (GI) strictures represent a difficult management problem given the limited therapeutic interventions available. We performed a systematic review of all published cases using mitomycin C in the treatment of GI strictures.

METHODS

Searches of MEDLINE and Embase databases were performed to identify studies reporting application of mitomycin C for GI strictures. Review of titles/abstracts, full review of potentially relevant studies, and data abstraction were performed independently by 2 authors.

RESULTS

Of 549 citations, 24 studies with 145 patients (74% pediatric and 26% adult) met inclusion criteria. Esophageal strictures were the most common (79%) site of refractory strictures treated with mitomycin C, with caustic injury the most common underlying etiology. The concentration (range, 0.1 to 2 mg/mL; median, 0.4 mg/mL), number of applications (range, 1 to 12; median, 1), duration of applications (range, 1 to 5; median, 2 min), and technique of application (cotton pledget, spray, injection, special catheters) varied among studies. Ninety-one patients (73%; children: 80%, adults: 59%) had a complete response; 26 (21%) had a partial response. Only 1 (0.7%) adverse event was reported: cutaneous sclerosis attributed to microperforation and mitomycin C extravastion after injection. Mean follow-up was 23 (4 to 60) months.

CONCLUSIONS

Local mitomycin C application seems to be a safe and effective therapy for benign refractory GI strictures of varying etiology in both pediatric and adult populations. Although the results of this systematic review are highly encouraging, it should be considered investigational. Additional randomized trials and larger prospective studies are needed to confirm these results and to better define the optimal dose, concentration, duration and technique of mitomycin C application.

Endoscopic dacryocystorhinostomy as treatment for lower lacrimal pathway obstructions in adults: Review article

Obstruction of the lacrimal pathway is manifested by epiphora, infection, and blurred vision as well as ocular and facial pain. Conservative treatments only achieve temporary relief of symptoms, thus surgery is the treatment of choice. Dacryocystorhinostomy (DCR) is recognized as the most suitable treatment for patients with obstructions of the lacrimal system at the level of the sac or in the nasolacrimal duct. The aim of this operation is to create a bypass between the lacrimal sac and the nasal cavity. During the past 2 decades, advances in rigid endoscopic equipment and other instruments have made it possible to obtain more information about the anatomic landmarks of the nasolacrimal system, which led to the development of less-invasive and safer endoscopic techniques. However, many parts of the treatment process related to endoscopic endonasal dacryocystorhinostomy (EN-DCR) still remain controversial. This article reviews the published literature about the technical issues associated with the success of EN-DCR, and clarifies the pros and cons of different pre- and postoperative procedures in adults with lower lacrimal pathway obstructions.

Topical mitomycin-C application in recurrent esophageal strictures after surgical repair of esophageal atresia

OBJECTIVES

The aim of the present study was to evaluate the efficacy and short-term safety of topical mitomycin-C, an antifibrotic agent, in preventing the recurrence of anastomotic strictures after surgical repair of esophageal atresia (EA).

METHODS

We retrospectively reviewed the medical records of patients with recurrent anastomotic strictures after EA surgery who underwent at least 3 esophageal dilations. We compared the outcome (ie, resolution of the stricture) of the group that received topical mitomycin-C treatment with endoscopic esophageal dilation with a historical cohort treated by dilations alone.

RESULTS

A total of 11 children received mitomycin-C concurrently with endoscopic dilations. After a median follow-up of 33 months (range 18-72), and a mean number of 5.4 dilations per patient (range 3-11), 8 of 11 patients achieved a resolution of their strictures, 2 patients remained with stenosis, and 1 patient needed a surgical correction. In the control group, 10 patients required an average of 3.7 (range 3-7) total dilations. After a follow-up of 125 months (range 35-266) after the last dilation, strictures in 9 of 10 children disappeared and the remaining patient was symptom free. No dysplasia related to mitomycin-C was demonstrated.

CONCLUSIONS

There is no benefit in the resolution of the stricture when adding mitomycin-C treatment compared with repeated esophageal dilations alone in historical controls. Further randomized controlled studies and a short- and long-term evaluation of safety are needed.

Clinical outcomes of dacryocystorhinostomy with or without intraoperative use of mitomycin C: a systematic review and meta-analysis

PURPOSE

To examine the possible benefit of intraoperative use of mitomycin C (MMC) application in dacryocystorhinostomy (DCR) and to assess its potential risk.

METHODS

Systematic review and meta-analysis of randomized-controlled trials (RCTs). A comprehensive literature search was performed according to a protocol set in advance. The participants included 811 patients of which 820 eyes were sampled for 14 RCTs. Only pertinent RCTs were identified and included in this meta-analysis. The primary efficacy measure was "patency of irrigation" at follow-up end point. The subjective outcome of "symptom relief" was also extracted as a secondary efficacy measure. For each study, relative risk was extracted. Heterogeneity, publication bias, subgroup, and meta-regression analyses were performed.

RESULTS

RevMan version 5.0 software was used for statistical analysis. In the primary efficacy measure, the use of MMC can significantly increase the rate of "patency of irrigation" [risk ratio (RR), 1.10; 95% confidence interval (CI), 1.04-1.17; P=0.0006]; the outcome of "symptom relief" was also affected by the use of MMC (RR, 1.15; 95% CI, 1.05-1.26; P=0.003). Sensitivity analysis suggested that the result was comparatively reliable.

CONCLUSION

Intraoperative use of MMC can bring about a positive effect to the outcomes of "patency of irrigation" and "symptom relief," which increases the success rate of DCR surgery.

Meta-analysis of the adjunctive use of mitomycin C in primary and revision, external and endonasal dacryocystorhinostomy

PURPOSE

To determine whether application of the anti-proliferation agent, mitomycin C (MMC), to the osteotomy site during dacryocystorhinostomy (DCR) surgery increases surgical success rates.

METHOD

We conducted a comprehensive meta-analysis of randomised controlled clinical studies relating to the adjunctive use of MMC in primary and revision, as well as external (EX-DCR) and endonasal DCR (EN-DCR).

RESULTS

15 studies met our inclusion criteria with a total of 850 DCR procedures. The mean concentration of MMC used was 0.3 mg/ml (range 0.02-0.75 mg/ml) and mean duration of application 18 min (range 2-30 min). MMC significantly reduced the failure rate of primary EX-DCR (risk ratio, RR, 0.51; 95% confidence interval, CI, 0.31-0.86) and revision EN-DCR (RR 0.43; 95% CI 0.21-0.89). The adjunctive use of MMC in primary EN-DCR, however, did not confer a significant reduction in failure rate compared with control (RR 0.94; 95% CI 0.44-2.04). We found a deficiency of evidence regarding the potential benefit of MMC in revision EX-DCR. Only two cases of adverse effects relating to the use of MMC were reported among the studies, both of which related to delayed wound healing.

CONCLUSIONS

Application of MMC to the osteotomy site is a safe and effective way of increasing surgical success rate in primary EX-DCR and revision EN-DCR, but does not provide any significant benefit in primary EN-DCR. Further studies are required to evaluate the potential effect of MMC in revision EX-DCR.

Impact of mitomycin C on the mRNA expression signatures of immunological biomarkers in eosinophilic nasal polyposis

BACKGROUND

The topical application of mitomycin C has been evaluated as a complementary therapy for eosinophilic nasal polyposis (ENP). However, the mechanism underlying the additional benefits of mitomycin C for the control of eosinophilic inflammation and prevention of posttherapeutic relapse remains to be elucidated. In this work, the aim was to characterize the gene expression profile by quantitative real-time polymerase chain reaction (qPCR) of proinflammatory and regulatory biomarkers that are typically associated with ENP and to assess the impact of the topical application of mitomycin C on the nasal mucosal tissue immunologic milieu after ENP surgery.

METHODS

We have selected 20 patients with ENP that were recommended to undergo surgical intervention. Normal mucosal tissue was obtained from healthy nasal mucosa from six patients with absence of eosinophilic infiltration. To test the effect of mitomycin C, one side of the maxillary sinus mucosa was selected for topical application of this drug and the other received no further treatment and acted as the control. The genes interleukin-4 (IL-4), IL-5, IL-10, IL-13, chemokine (C-C motif) ligand 5 (CCL5), CCL24, colony-stimulating factor 2 (CSF2), transforming growth factor beta 1 (TGFB1), tumor necrosis factor alpha (TNF-alpha), and beta actin (ACTB) were selected for gene expression analysis by qPCR.

RESULTS

The data showed higher expression of proinflammatory biomarkers and lower levels of regulatory TGFB1 transcripts in ENP mucosal tissue. Surgery with topical application of mitomycin C induced a prominent transcriptional down-regulation of the immunologic biomarkers, CCL24, TNF-alpha, CSF2, and IL-5, in ENP mucosal tissue. Additionally, this treatment restored the levels of chemokines and cytokines to those observed in the nasal mucosal tissue of control subjects, except for TGFB1, which remained below the reference pattern. Moreover, CSF2 was identified as a putative biomarker with significant predictive value for complementary prophylactic purposes after surgery in ENP patients.

CONCLUSION

After the characterization of the expression signatures of immunologic biomarkers in ENP, we observed that the topical use of mitomycin C is important for the reestablishment of the immunologic microenvironment of a normal expression profile of biomarkers involved in ENP mucosal tissue.

Efficacy of mitomycin C in endoscopic dacryocystorhinostomy: a systematic review and meta-analysis

BACKGROUND

A number of published comparative studies have been conducted to evaluate the efficacy and safety of intraoperative mitomycin C (MMC) in endoscopic dacryocystorhinostomy (EN-DCR). However, results have not always been consistent. Therefore, we carried out a meta-analysis to compare the clinical results of EN-DCR with and without MMC.

METHODS AND FINDINGS

A comprehensive literature search of Cochrane Library, PubMed and EMBASE to identify relevant trials comparing EN-DCR with and without MMC. Eleven studies including 574 eyes were included in this meta-analysis. The success was defined as patency of the nasolacrimal canal and symptomatic improvement. There was significantly higher success rate in the MMC group in comparison with control group [RR = 1.12, 95% CI (1.04, 1.20), P = 0.004]. A sensitivity analysis after the non-randomized controlled trials were excluded from the meta-analysis demonstrated no differences compared with the overall results. Subgroup analyses showed that MMC group had a significantly higher success rate than control group in primary and revision EN-DCR, and EN-DCR without silicone intubation, but no difference in the subgroup of with silicone intubation. The size of the osteotomy site was bigger in the MMC group compared to the control group at 3 months [WMD = 7.65, 95% CI (0.33, 14.98), P = 0.041] and 6 months [WMD = 9.28, 95% CI (2.45, 16.11), P = 0.008] after surgery. However, there was statistically significant difference in the osteotomy surface area between the two groups at 12 months after surgery [WMD = 11.63, 95% CI (-1.04, 24.29), P = 0.072].

CONCLUSION

Intraoperative MMC application seems to be a safe adjuvant that could reduce the closure rate of the osteotomy and enhance the success rate after both primary and revision EN-DCR.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01772277.

Mitomycin C–Enhanced Revision Endoscopic Dacryocystorhinostomy

Objectives

(1) To conduct an adequately powered randomized controlled trial investigating the safety and efficacy of mitomycin C–enhanced revision endoscopic dacryocystorhinostomy (DCR) and (2) to analyze causes of failure after primary endoscopic DCR.

Study Design

A randomized controlled study.

Setting

General hospital.

Subjects and Methods

Seventy-six revision endoscopic DCRs were randomized into 2 groups: endoscopic DCR with mitomycin (group I), where 0.5 mg/mL mitomycin C was applied for 10 minutes, and endoscopic DCR without mitomycin (group II). Follow-up settings were done to document the patient’s subjective improvement, to judge ostium patency on irrigation, and to record any complications.

Results

Causes of failure in the original 92 patients included canalicular obstruction (14%), small misplaced bony window (43%), very small nasolacrimal stoma due to development of synechia (23%), and complete closure of nasolacrimal stoma with tough fibrous tissue (63%). There was no significant difference between the 2 groups in subjective and objective success rates and adverse events. Group I demonstrated a significantly longer operative time and a significantly lower number of debridement sessions (mean of 1.2 vs 1.9).

Conclusions

Recurrent nasolacrimal duct obstruction after primary endoscopic DCR is mainly due to reclosure of the nasolacrimal stoma with synechia and fashioning of the small misplaced bony window. Mitomycin C does not increase the success rate of revision endoscopic DCR. It is a safe procedure and may be of value only in patients inaccessible to strict follow-up because it induces a better healing profile in terms of mucosal recovery, wound healing, and less need for debridement sessions.

Endoscopic Dacryocystorhinostomy with Double Posteriorly Based Nasal and Lacrimal Flaps

Objectives

To conduct the first prospective randomized controlled trial assessing and comparing the safety and efficacy of endoscopic dacryocystorhinostomy (DCR) with double posteriorly based nasal and lacrimal flaps to conventional endoscopic DCR in adult patients with acquired complete nasolacrimal obstruction.

Study Design

A prospective randomized controlled study.

Setting

General hospital.

Subjects and Methods

Seventy-four adult patients with a total of 80 procedures were recruited to undergo endoscopic DCR. They were prospectively equally randomized into 2 groups: endoscopic DCR with flaps (group I) and conventional endoscopic DCR (group II). Regular follow-up settings were done to document the patient’s subjective improvement, judge ostium patency on irrigation, and record any complications.

Results

Endoscopic DCR with flaps had a higher (92.1%) but nonsignificant difference in success rate when compared with conventional endoscopic DCR (87.4%). There was no significant difference between the 2 techniques in operative time, adverse events, and tolerability of the technique to be done under local anesthesia with minimal sedation. Group I demonstrated a significantly lower number of debridement sessions than did group II.

Conclusion

Endoscopic DCR with double posteriorly based nasal and lacrimal flaps provides a viable alternative to conventional endoscopic DCR in managing acquired nasolacrimal duct obstructions in adults. It has a comparable success rate, operative time, and safety profile, with a suggestion of a better healing profile in terms of mucosal recovery, wound healing, and less need for debridement sessions.