Final results of a European, multicentre, prospective, observational study of Permacol™ collagen paste injection for the treatment of anal fistula

Perianal Fistula; from Etiology to Treatment - A Review

Anal fistula has been a challenging clinical issue for years due to its complex pathogenesis. The risk of frequent recurrence and incontinence complicates long-term treatment. Recent scientific literature has reviewed new techniques used for anal fistula treatment in recent years, assessing the advantages and disadvantages of each based on clinical outcomes. Although surgery is the main method used to treat anal fistula, there is no simple technique that can completely heal complex anal fistula. The surgical treatment should consider the healing outcome and the protection of anal function comprehensively. Several innovative techniques have emerged in recent years, such as combined techniques based on drainage seton and LIFT-plug, which appear to be relatively effective therapies. However, more multi-center prospective trials with long-term follow-up are needed to validate their effectiveness. In some situations, medical treatment may also be considered.

European Society of Coloproctology: Guidelines for diagnosis and treatment of cryptoglandular anal fistula

AIM

The primary aim of the European Society of Coloproctology (ESCP) Guideline Development Group (GDG) was to produce high-quality, evidence-based guidelines for the management of cryptoglandular anal fistula with input from a multidisciplinary group and using transparent, reproducible methodology.

METHODS

Previously published methodology in guideline development by the ESCP has been replicated in this project. The guideline development process followed the requirements of the AGREE-S tool kit. Six phases can be identified in the methodology. Phase one sets the scope of the guideline, which addresses the diagnostic and therapeutic management of perianal abscess and cryptoglandular anal fistula in adult patients presenting to secondary care. The target population for this guideline are healthcare practitioners in secondary care and patients interested in understanding the clinical evidence available for various surgical interventions for anal fistula. Phase two involved formulation of the GDG. The GDG consisted of 21 coloproctologists, three research fellows, a radiologist and a methodologist. Stakeholders were chosen for their clinical and academic involvement in the management of anal fistula as well as being representative of the geographical variation among the ESCP membership. Five patients were recruited from patient groups to review the draft guideline. These patients attended two virtual meetings to discuss the evidence and suggest amendments. In phase three, patient/population, intervention, comparison and outcomes questions were formulated by the GDG. The GDG ratified 250 questions and chose 45 for inclusion in the guideline. In phase four, critical and important outcomes were confirmed for inclusion. Important outcomes were pain and wound healing. Critical outcomes were fistula healing, fistula recurrence and incontinence. These outcomes formed part of the inclusion criteria for the literature search. In phase five, a literature search was performed of MEDLINE (Ovid), PubMed, Embase (Ovid) and the Cochrane Database of Systematic Reviews by eight teams of the GDG. Data were extracted and submitted for review by the GDG in a draft guideline. The most recent systematic reviews were prioritized for inclusion. Studies published since the most recent systematic review were included in our analysis by conducting a new meta-analysis using Review manager. In phase six, recommendations were formulated, using grading of recommendations, assessment, development, and evaluations, in three virtual meetings of the GDG.

RESULTS

In seven sections covering the diagnostic and therapeutic management of perianal abscess and cryptoglandular anal fistula, there are 42 recommendations.

CONCLUSION

This is an up-to-date international guideline on the management of cryptoglandular anal fistula using methodology prescribed by the AGREE enterprise.

Collagen treatment of complex anorectal fistula: 3 years follow-up

Fistula in ano is a common anorectal disease in adults. Currently, surgery remains the definitive therapeutic approach, but in some cases, it can lead to serious complications as faecal or gas incontinence. Therefore, sphincter sparing treatments should be considered for complex fistulas. One of the sphincteric preserving treatment is the filling with a dermal extract commonly called "collagen glue" as Salvecoll-E^® gel. This is a multicentric, prospective, observational study on the use of Salvecoll-E^® gel in treatment of complex anal fistulas. We treated 70 patients from May 2016 to May 2017. In the first phase, we debrided the fistula tract using a loose seton kept for 4-6 weeks. In the second phase, the seton was removed and the fistula tract was filled with Salvecoll-E^® gel. In this article, we report results at 36 months of follow-up. Fifty patients (71.4%) had completely healed fistula within 36 months of follow-up. Twenty-eight patients (28.2%) had recurrences. Among these failures, 65% were within 6 months. All low transphincteric fistulas healed. Recurrences occurred only in median and high transphincteric fistulas. No patient had a worsening of continence status measured with Cleveland Clinic Florida Incontinence Severity score. Salvecoll-E^® gel is a recent finding among sphincter-sparing treatments. In this study, we demonstrate that it is a safe option in the treatment of complex fistulas. Final results are satisfactory and in line with the best results published in literature among mini-invasive treatments.

Treatments for the amelioration of persistent factors in complex anal fistula

Anal fistulae are abnormal hollow connections between the wall of the anal canal and the perianal skin around the anus that have remained a burden on the medical sector for centuries. The complexity of this disease is attributed to a number of factors such as the degree of associated sphincter muscle, concomitant illnesses, existence of multiple fistulous tracts and the number of previous interventions. Persistence of a complex anal fistula can cause a decline in patient's physical quality of life as well as impact on the psychological status of patients who often suffer from anxiety and depression. Surgical intervention remains the gold standard for treatment, however; the risk of incontinence and high recurrence potential has led to interest into developing alternative treatment approaches such as the use of biologics, bioactives and biomaterials. One potential reason for these varied outcomes could be the multifactorial interplay between genetic, immune-related, environmental, and microbial persistence factors on tissue regeneration. Recent observations have proposed that adverse inflammatory mediators may contribute more than microbial factors. The moderate to high success rates of biotechnological advances (mesenchymal stem cells and biomaterial scaffolds) show promise as therapies for the amelioration of adverse persistent factors while facilitating a means to closing the fistula tract. The purpose of this review is to outline recent advances in biologics and combination therapies to treat persistent factors associated with complex anal fistula.

Efficacy of Permacol injection for perianal fistulas in a tertiary referral population: poor outcome in patients with complex fistulas

AIM

Injection of Permacol collagen paste can be used as a sphincter-sparing treatment for perianal fistulas. In a tertiary referral population we aimed to evaluate the efficacy of Permacol injection and the clinical and fistula-related factors associated with recurrence.

METHOD

This was a retrospective analysis of consecutive patients with perianal fistulas treated with Permacol injection at a specialist centre between June 2015 and April 2019. Endoanal ultrasonography was systematically reanalysed, blinded to treatment outcome. Rectovaginal, anovaginal and Crohn's disease fistulas were excluded. Healed fistulas were defined as absent anal symptoms and a closed external opening on physical examination at a minimum follow-up of 6 months. Regression analyses were performed to identify factors associated with unhealed fistulas.

RESULTS

A total of 90 patients (51 men; median age 45 years) were analysed. Seventy-two (80.0%) patients had complex perianal fistulas (greater than one-third sphincter involvement or multiple tracts). After a single Permacol injection, fistulas were healed in 20 (22.2%) patients at 3 months follow-up and in 18 (20.0%) patients at a median follow-up of 30 months (interquartile range 17-37). Eight (11.1%) patients with unhealed fistulas had significant improvement in their symptoms. Complex fistulas were significantly associated with unhealed status [OR 3.53 (95% CI 1.12-11.09); p = 0.031]. Twenty patients underwent subsequent Permacol injections, which were successful in six (30.0%) patients after one (n = 3) or two (n = 3) additional injections.

CONCLUSION

This largest study to date in patients with mainly complex perianal fistulas, demonstrated that the efficacy of a single Permacol injection was only 20%. Complex fistulas were associated with a poor outcome.

Simple fistula-in-ano: is it all simple? A systematic review

BACKGROUND

Simple anal fistula is one of the most common causes of proctological surgery and fistulotomy is considered the gold standard. This procedure, however, may cause complications. The aim of this systematic review was to assess the surgical treatment of simple anal fistula with traditional and sphincter-sparing techniques.

METHODS

A literature research was performed using PubMed, Cochrane, and Google Scholar to identify studies on the surgical treatment of simple anal fistulas. Observational studies and randomized clinical trials were included. We assessed the risk of bias of included studies using the Jadad scale for randomized controlled trials, and the MINORS Scale for the remaining studies.

RESULTS

The search returned 456 records, and 66 studies were found to be eligible. The quality of the studies was generally low. A total of 4883 patients with a simple anal fistula underwent a sphincter-cutting procedure, mainly fistulotomy, with a weighted average healing rate of 93.7%, while any postoperative continence impairment was reported in 12.7% of patients. Sphincter-sparing techniques were adopted to treat 602 patients affected by simple anal fistula, reaching a weighted average success rate of 77.7%, with no study reporting a significant postoperative incontinence rate. The postoperative onset of fecal incontinence and the recurrence of the disease reduced patients' quality of life and satisfaction.

CONCLUSIONS

Surgical treatment of simple anal fistulas with sphincter-cutting procedures provides excellent cure rates, even if postoperative fecal incontinence is not a negligible risk. A sphincter-sparing procedure could be useful in selected patients.

Three Decades of Research on Recombinant Collagens: Reinventing the Wheel or Developing New Biomedical Products?

Collagens provide the building blocks for diverse tissues and organs. Furthermore, these proteins act as signaling molecules that control cell behavior during organ development, growth, and repair. Their long half-life, mechanical strength, ability to assemble into fibrils and networks, biocompatibility, and abundance from readily available discarded animal tissues make collagens an attractive material in biomedicine, drug and food industries, and cosmetic products. About three decades ago, pioneering experiments led to recombinant human collagens' expression, thereby initiating studies on the potential use of these proteins as substitutes for the animal-derived collagens. Since then, scientists have utilized various systems to produce native-like recombinant collagens and their fragments. They also tested these collagens as materials to repair tissues, deliver drugs, and serve as therapeutics. Although many tests demonstrated that recombinant collagens perform as well as their native counterparts, the recombinant collagen technology has not yet been adopted by the biomedical, pharmaceutical, or food industry. This paper highlights recent technologies to produce and utilize recombinant collagens, and it contemplates their prospects and limitations.

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.

Evaluation and management of perianal abscess and anal fistula: SICCR position statement

Perianal sepsis is a common condition ranging from acute abscess to chronic anal fistula. In most cases, the source is considered to be a non-specific cryptoglandular infection starting from the intersphincteric space. Surgery is the main treatment and several procedures have been developed, but the risks of recurrence and of impairment of continence still seem to be an unresolved issue. This statement reviews the pertinent literature and provides evidence-based recommendations to improve individualized management of patients.

Comparison of porcine collagen paste injection and rectal advancement flap for the treatment of complex cryptoglandular anal fistulas: a 2-year follow-up study

BACKGROUND

Rectal advancement flap is the standard surgical treatment for complex cryptoglandular anal fistulas, while Permacol™ collagen paste is considered an innovative treatment option for anorectal fistulas. This study aimed to compare the clinical outcomes of patients with complex cryptoglandular fistulas treated by endorectal advancement flap versus Permacol™ paste.

METHODS

This study was a retrospective analysis of patients with complex cryptoglandular anal fistulas. Thirty-one patients were treated with the rectal advancement flap (RAF group), while 21 were treated with Permacol™ paste injection (PP group). In PP group, the approach consisted of loose seton positioning followed several weeks later by closure internal opening with a resorbable sutures associated with paste injection into the fistula track. Clinical outcomes were assessed in terms of healing rate, faecal continence and patient satisfaction.

RESULTS

Seton drainage was done in all patients in both groups for a median duration of 8 weeks (range 4-18 weeks) before the final surgery (p = 0.719). No patient had faecal incontinence (CGS ≥ 5) preoperatively. Five patients (16%) in the RAF group and one (5%) in the PP group experienced faecal incontinence postoperatively. The 2-year disease-free survival was 65% in the RAF group and 52% in the PP group (p = 0.659). The median satisfaction scores were 5 (range 1-10) in the RAF group and 7 (range 2-10) in the PP group (p = 0.299).

CONCLUSION

The RAF appeared superior to PP in terms of fistula healing, although this result was not statistically significant. On the contrary, PP has a potential advantage in terms of continence disorders. Permacol™ paste can be considered as the initial treatment option for complex cryptoglandular anal fistulas in patients with faecal continence disorders.

Permacol Collagen Paste Injection for Treatment of Complex Cryptoglandular Anal Fistulas: An Observational Cohort Study With a 2-Year Follow-up

BACKGROUND

Permacol paste injection is a novel treatment approach for complex cryptoglandular anal fistulas. This study was performed to evaluate the long-term clinical outcomes of treatment with Permacol paste for complex cryptoglandular fistulas.

METHODS

Patients with primary or recurrent complex cryptoglandular anal fistulas treated with Permacol paste from 2014 to 2016 were retrospectively analyzed.

RESULTS

A total of 46 patients (median age, 41.3 years; 21 female) underwent Permacol paste injection; 20 patients (43%) had previously undergone failed fistula surgery. The patients had experienced anal fistula-related symptoms for a median of 10 weeks (range, 3-50 weeks). All patients had a draining seton in situ for a median of 10 weeks (range, 4-46 weeks). The median follow-up time was 24 months (range, 1-25 months). At the 1-month follow-up, 2 patients had paste extrusion and 2 had anal abscesses. The mean preoperative Continence Grading Scale score was 1.10 ± 1.40, and that at 3 months postoperatively was 1.13 ± 1.39 ( P = .322). There was a significant difference in the preoperative and the 1- and 3-month postoperative pain scores ( P < .001). At the 24-month follow-up, the healing rate was 50% (n = 23). A total of 19 patients (41%) with a recurrent fistula after failed Permacol paste injection required additional operative procedures. The satisfaction rate at the 2-year follow-up was 65%.

CONCLUSION

Permacol paste injection is minimally invasive and technically easy to perform. It can be considered as a viable and reasonable option for the treatment of complex cryptoglandular anal fistulas in patients with fecal continence disorders.

Permacol™ Collagen Paste Injection in Anal Fistula Treatment: A Retrospective Study with One-Year Follow-Up

INTRODUCTION

This study aimed to evaluate the applicability, safety, results, and functional performance of Permacol™ collagen paste injection in patients with an anal fistula.

METHODS

Thirty-one patients with anal fistula underwent Permacol™ collagen paste injection between February 2015 and February 2017. The patients were followed up for a total of 12 months with recovery conditions monitored at intervals of 3, 6, and 12 months. Preoperative insertion of seton was performed in 15 patients for a period of 6-8 weeks and 2 patients for a period of 12 weeks.

RESULTS

A trans-sphincteric anal fistula was present in 20 patients and an intersphincteric fistula was present in 11 patients. There was a recurrence in 7 patients (22.5%): 1 patient (3.2%) after 1-month follow-up, 3 patients (9.7%) after 3-month follow-up, 2 patients (6.5%) after 6-month follow-up, and 1 patient (3.2%) after 12-month follow-up. A complete recovery was observed in 24 (77.5%) patients after a 12-month follow-up. The mean Fecal Incontinence Severity Index score was 0.29 ± 0.64 preoperatively and 0.55 ± 1.03 after 12 months.

CONCLUSION

In this study, we show that treatment of patients with an anal fistula by injection of Permacol™ is a safe and successful method that does not compromise continence.