LIFT and BioLIFT: a 10-Year Single-Centre Experience of Treating Complex Fistula-In-Ano With Ligation of Intersphincteric Fistula Tract Procedure With or Without Bio-prosthetic Reinforcement (BioLIFT)

Comparison of BioLIFT versus LIFT for the treatment of trans-sphincteric anal fistula: a protocol for systematic review and meta-analysis

INTRODUCTION

Identifying the optimal treatment for anal fistula has been challenging. Since first reported in 2007, the ligation of the intersphincteric fistula tract (LIFT) procedure has reported healing rates between 40% and 95% and is being increasingly adopted. The BioLIFT is an augmentation of the LIFT with an intersphincteric bioprosthetic mesh and has reported healing rates between 69% and 94%. Despite increased costs and potential complications associated with mesh, the evidence comparing healing rates between BioLIFT and LIFT is unknown. This study details the protocol for a systematic review and meta-analysis of BioLIFT and LIFT to compare outcomes associated with each procedure.

METHODS AND ANALYSIS

MEDLINE, EMBASE and the Cochrane Database will be searched from inception using a search strategy designed by an information specialist. Randomised controlled trials, prospective and retrospective cohort studies, consecutive series, cross-sectional studies and case series with more than five patients will be included. Both comparative and single group studies will be included. The eligible population will be adult patients undergoing BioLIFT or LIFT for trans-sphincteric anal fistula. The primary outcome will be primary healing rate. Secondary outcomes will capture secondary healing rate and complications. Abstract, full text and data extraction will be completed independently and in duplicate by two reviewers. Study risk of bias will be assessed using Risk of Bias In Non-randomized Studies - of Interventions and the Risk of Bias (RoB 2.0) tool. Quality of evidence for outcomes will be evaluated using Grading of Recommendations, Assessment, Development and Evaluations criteria. A meta-analysis will be performed using a random-effects inverse variance model. Subgroup and sensitivity analyses will be explored in relation to complex fistula characteristics and patients who have undergone previous LIFT. Heterogeneity will be assessed using the I2 statistic.

ETHICS AND DISSEMINATION

This review does not require research ethics board approval. This study will be completed in September 2022. The findings of this study will be disseminated through peer-reviewed international conferences and journals.

PROSPERO REGISTRATION NUMBER

CRD42020127996.

A Systematic Review of Epidemiology and Outcomes Associated with Local Surgical and Intersphincteric Ligation Procedures for Complex Cryptoglandular Fistulas

INTRODUCTION

This systematic literature review (SLR) assessed incidence/prevalence of cryptoglandular fistulas (CCF) and outcomes associated with local surgical and intersphincteric ligation procedures for CCFs.

METHODS

Two trained reviewers searched PubMed and Embase for observational studies evaluating the incidence/prevalence of cryptoglandular fistula and clinical outcomes of treatments for CCF after local surgical and intersphincteric ligation procedures for CCF.

RESULTS

In total 148 studies met a priori eligibility criteria for all cryptoglandular fistulas and all intervention types. Of those, two assessed incidence/prevalence of cryptoglandular fistulas. Eighteen reported clinical outcomes of surgeries of interest in CCF and were published in the past 5 years. Prevalence was reported as 1.35/10,000 non-Crohn's patients, and 52.6% of non-IBD patients were found to progress from anorectal abscess to fistula over 12 months. Primary healing rates ranged from 57.1% to 100%; recurrence occurred in a range of 4.9-60.7% and failure in 2.8-18.0% of patients. Limited published evidence suggests postoperative fecal incontinence and long-term postoperative pain were rare. Several of the studies were limited by single-center design with small sample sizes and short follow-up durations.

DISCUSSION

This SLR summarizes outcomes from specific surgical procedures for the treatment of CCF. Healing rates vary according to procedure and clinical factors. Differences in study design, outcome definition, and length of follow-up prevent direct comparison. Overall, published studies offer a wide range of findings with respect to recurrence. Postsurgical incontinence and long-term postoperative pain were rare in the included studies, but more research is needed to confirm rates of these conditions following CCF treatments.

CONCLUSION

Published studies on the epidemiology of CCF are rare and limited. Outcomes of local surgical and intersphincteric ligation procedures show differing success and failure rates, and more research is needed to compare outcomes across various procedures. (PROSPERO; registration number CRD42020177732).

Comparison between recent sphincter-sparing procedures for complex anal fistulas-ligation of intersphincteric tract vs transanal opening of intersphincteric space

Complex anal fistulas are difficult to treat. The main reasons for this are a higher recurrence rate and the risk of disrupting the continence mechanism because of sphincter involvement. Due to this, several sphincter-sparing procedures have been developed in the last two decades. Though moderately successful in simple fistulas (50%-75% healing rate), the healing rates in complex fistulas for most of these procedures has been dismal. Only two procedures, ligation of intersphincteric fistula tract and transanal opening of intersphincteric space have been shown to have good success rates in complex fistulas (60%-95%). Both of these procedures preserve continence while achieving high success rates. In this opinion review, I shall outline the history, compare the pros and cons, indications and contraindications and future application of both these procedures for the management of complex anal fistulas.

A PILOT STUDY on the Clinical and Functional Outcomes of an Improvised Technique of Core-cut Fistulectomy for Fistula-in-ano

BACKGROUND

Anal fistulae are difficult to treat entities and minimally invasive procedures are evolving with promises. Our improvised technique is a simple and easy day-care procedure for simple fistulae.

AIM

To evaluate the outcomes of a technical modification in the procedure of core-cut fistulectomy in simple cryptoglandular fistula-in-ano.

METHODS

47 patients of fistula-in-ano presenting to the out-patient of the General Surgery department at All India Institute of Medical Sciences, Bhopal, from November 2018 to March 2020 were selected. A complete history, physical examination followed by relevant investigations were meticulously performed and recorded. They were operated using an improvised core-cut technique, under a pudendal nerve block. Patients were kept on follow-up for a minimum of 6 months period to note the outcome of the surgery.

RESULTS

The mean age was 37 ± 13.17 years with a male: female ratio of 5.1:1. The most common clinical presentation was perianal discharge in 96% of patients followed by pain and pruritus ani in 45% and 32%, respectively. 93.62% were inter-sphincteric, and 6.38% were trans-sphincteric. Extra-sphincteric and supra-levator fistulae were excluded from the study. The mean operative time was 17 ± 10.19 minutes. The mean healing time was 19.21 ± 5.99 days. The success rate of this novel technique of core-cut was calculated to be 89.37%. The rate of recurrence was calculated to be 10.63% (5 out of 47 patients). None of our patients developed incontinence.

CONCLUSION

Our pilot study results for simple fistulae-in-ano had less morbidity, postoperative pain, better wound healing, patient satisfaction, and compliance with low risk of recurrence, and no incontinence. It could hence be recommended for larger groups and more complicated fistulae in the future.

Efficacy and Safety of Sphincter-Preserving Surgery in the Treatment of Complex Anal Fistula: A Network Meta-Analysis

Background

There are many surgical methods of sphincter preservation in treating complex anal fistula, but the therapeutic effects of each operation are different. Therefore, this study aimed to compare the impact of other treatment methods through a network meta-analysis to evaluate the best sphincter preservation method for treating complex anal fistula.

Methods

We searched PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure, Chinese Biomedical Literature Database, VIP Journal Database, and the Wanfang Database to collate randomized controlled trials on sphincter-preserving surgery for complex anal fistula.

Results

A total of 29 articles were included in this meta-analysis. The cure rates showed no statistically significant differences between any two interventions (P > 0.05). The recurrence rate results showed that the rate of patients after Fistulectomy was higher than others (P < 0.05). The incidence rate of complications showed that the incidence rate after fistulectomy treatment was higher than that of others (P < 0.05). The surface under the cumulative ranking (SUCRA) was used to arrange their advantages and disadvantages, and a larger SUCRA value indicates that the intervention may be more effective. The results showed that TROPIS may have the highest cure rate (SUCRA = 78.6%), stem cell transplantation (SCT) may have the lowest recurrence rate (SUCRA = 85.5%), and imLIFT may have the least complications (SUCRA = 88.2%).

Conclusion

According to the existing literature data, for patients with complex anal fistula, TROPIS may be the surgical method with the highest cure rate, SCT may be the treatment method with the lowest recurrence rate, and imLIFT may be the surgical method with the lowest incidence of postoperative complications.

Systematic Review Registration

PROSPERO, identifier: CRD42020221907.

Anal fistula at roof of ischiorectal fossa inside levator-ani muscle (RIFIL): a new highly complex anal fistula diagnosed on MRI

BACKGROUND

As experience with anal fistula imaging (MRI) has increased, new pathways of fistula extension have been identified. A recently described pathway is the  'outer-sphincteric space' present between the external anal sphincter and its covering outer fascia. A new type of complex fistula is being described which is present in the outer-sphincteric space and continues superiorly along the lateral border of the external anal sphincter to the infero-lateral surface of the puborectalis and levator-ani. In effect, these outer-sphincteric fistulas are at the roof of the ischiorectal fossa inside the levator muscle (RIFIL). These fistulas are not transsphincteric fistulas as they remain inside the levator muscle and do not enter the ischiorectal fossa.

METHODS

The MRI scans of consecutive anal fistula patients operated over the last two years were analyzed retrospectively.

RESULTS

Of 419 operated fistula patients analyzed, 42(10%) had RIFIL and 377 non-RIFIL fistulas. Compared to non-RIFIL fistulas, there were significantly more recurrent, multiple tracts, horseshoe, supralevator, and suprasphincteric fistulas in the RIFIL group. RIFIL fistulas were significantly more complex than non-RIFIL fistulas(85.7% vs 38.5%, p < 0.00001) and the surgery failure rate was also significantly higher in the RIFIL group (30.6%) than in the non-RIFIL fistula (7.2%) group(p = 0.0001).

CONCLUSION

RIFIL are highly complex fistulas. Proper diagnosis by MRI, surgical access, and subsequent management of these fistulas is quite challenging and they are associated with poor prognosis. Missing their diagnosis would lead to higher recurrence rate. These have not been described previously and were perhaps confused with high transsphincteric infralevator fistulas in ischiorectal fossa.

The new pathways of spread of anal fistula and the pivotal role of MRI in discovering them

Conventionally, in the pathophysiology of anal fistulas, there is only one space considered significant for the spread of pus in the sphincter complex: the intersphincteric space. However, with increasing experience in the high-resolution MRI, and more focus being given on managing fistulas through the intersphincteric space, two additional pathways of fistula spread have been identified. First is a newly described space labelled as the outer-sphincteric space. Second is a known anatomical space (inner intersphincteric space), but this space was considered as irrelevant from the point of view of fistula spread. The conventional intersphincteric space is present in between these two spaces and is referred as 'middle intersphincteric space' in this paper. These three distinct spaces have significant clinical implications as the pattern of spread of pus is quite different in each space, and the management also differs for fistula tract in each of these spaces.

Porcine dermal collagen mesh (Permacol™) as a bioprosthesis in the ligation of intersphincteric tract (BioLIFT) procedure

BACKGROUND

Ligation of intersphincteric tract (LIFT) is a sphincter-saving technique used to treat anal fistulas. Incorporation of a bioprosthesis in LIFT (BioLIFT) aims to improve healing. The use of cross-linked porcine dermal collagen mesh Permacol™ in BioLIFT has never been investigated. The aim of this study was to compare the healing rates and outcome of LIFT and BioLIFT for complex anal fistulas using the Permacol™ biological mesh.

METHODS

A retrospective analysis of all patients having LIFT or BioLIFT for complex fistulas from January 2010 to November 2019 was performed in a tertiary referral centre. Patient data from a prospectively collected database of all patients having LIFT or BioLIFT were analyzed.

RESULTS

LIFT and BioLIFT were performed in 48 (82.8%) and 10 (17.2%) patients, respectively. All BioLIFT patients had previous interventions for their fistulas compared to 30 (62.5%) of patients who had LIFT, p = 0.023. The primary healing rate for LIFT was 87.5% (42/48) compared to 80% (8/10) in BioLIFT, (p = 0.42). Eight (13.8%) patients developed complications, 6 (12.5%) in the LIFT group vs 2 (20%) in the BioLIFT group (p = 0.62). On univariate analysis, the number of previous operations was predictive of complications (p = 0.03). BioLIFT was not associated with complication (OR = 1.75, 95% CI: 0.30-10.3, p = 0.54) or primary healing (OR = 0.57, 95% CI: 0.97-3.36, p = 0.54). There was no significant difference in recurrence (LIFT 12.5% vs BioLIFT 0%, p = 0.58). Kaplan-Meier analysis found no difference in time to recurrence between the two groups (p = 0.65).

CONCLUSION

Permacol™ mesh in BioLIFT is feasible and achieves a high primary healing rate of 80%. Prospective evidence is needed to establish the benefits of BioLIFT and determine whether Permacol™ is superior to the non-cross-linked porcine submucosal mesh.