Histological evidence for enhanced anal fistula repair using autologous fibroblasts in a dermal collagen matrix

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.

Novel biological strategies in the management of anal fistula

BACKGROUND

The mostly widely studied biomaterials for the sphincter sparing treatment of anal fistulas are fibrin glue and the anal fistula plug (AFP). However their overall mean clinical success is only 50-60%. As the understanding of the pathology of anal fistula, wound healing and the host response to materials has improved, so new biological sphincter-sparing strategies have been developed. The aim of this review is to assess the safety and efficacy of these novel techniques.

METHOD

PubMed, the Cochrane database and EMBASE were independently searched. All studies that investigated the potential of a biomaterial (defined as any synthetic or biologically derived substance in contact with host tissue) to augment the healing of anal fistula without sphincter division were included. Studies solely describing the role of fibrin glue or an AFP were excluded. Data extraction included type of material, fistula aetiology, treatment of the primary tract, fistula healing, incontinence, duration of follow-up and any specific complications. Systematic quality assessment of the included articles was performed.

RESULTS

Twenty-three articles were finally selected for review. These included a variety of biological and synthetic systems that were employed to deliver selected components of the extracellular matrix, growth factors, cytokines, stem cells or drugs to the fistula tract.

CONCLUSION

To date no study matches fistulotomy with regard to long-term fistula eradication rate. This is probably due to implant extrusion, inadequate track preparation or an unsuitable material. Future techniques need to address all these issues to ensure success. Success should be validated by MRI or long-term follow-up.

Management of idiopathic anal fistula using cross-linked collagen: a prospective phase 1 study

AIM

Fibrin glue and porcine intestinal submucosa are used in novel sphincter-preserving techniques to heal anal fistulae. However, their success is highly variable and decreases with the length of follow up. The aim of this study was to assess the safety, feasibility and potential efficacy of another novel agent, cross-linked collagen, in two different physical formats, to heal anal fistulae.

METHOD

Prospectively recruited patients underwent symptom, continence and anal physiology assessments and magnetic resonance imaging. Patients with secondary tracts or acute sepsis were excluded. At operation, participants were randomized to receiving a solid collagen implant or collagen fibres suspended in fibrin glue. Follow up included repeat symptom, continence and physiological assessments at 3 months, and regular clinical review thereafter.

RESULTS

Twenty-nine of 43 entrants were eligible for inclusion. Thirteen patients received the collagen implant, and 16 collagen-fibrin glue. Three months postoperation, no patient experienced acute sepsis or continence disturbance, and sphincter function and integrity were unchanged. At 29 months, 12 of 15 (one lost to follow up) patients treated with collagen-fibrin glue were healed, compared with seven of 13 who received the implant.

CONCLUSION

In the short-to-medium term, both techniques are safe and equally effective. The results justify continued research into the use of biomaterials to heal anal fistulae.

Perianal fistulae in Crohn's Disease: current and future approaches to treatment

: affecting sphincter integrity and continence. Traditional surgical and medical approaches are not without their limitations and may result in either comorbidity, such as fecal incontinence, or incomplete healing of the fistulae. Over the last 2 decades these limitations have led to a paradigm shift toward the use of biomaterials, and more recently cell-based therapies, which have met with variable degrees of success. This review discusses the traditional and current methods of treatment, as well as emerging and possible alternative approaches that may improve fistula healing.

Microporous collagen spheres produced via thermally induced phase separation for tissue regeneration

Collagen is an abundant protein found in the extracellular matrix of many tissues. Due to its biocompatibility, it is a potentially ideal biomaterial for many tissue engineering applications. However, harvested collagen often requires restructuring into a three-dimensional matrix to facilitate applications such as implantation into poorly accessible tissue cavities. The aim of the current study was to produce a conformable collagen-based scaffold material capable of supporting tissue regeneration for use in wound repair applications. Microporous collagen spheres were prepared using a thermally induced phase separation (TIPS) technique and their biocompatibility was assessed. The collagen spheres were successfully cross-linked with glutaraldehyde vapour, rendering them mechanically more stable. When cultured with myofibroblasts the collagen spheres stimulated a prolonged significant increase in secretion of the angiogenic growth factor, vascular endothelial growth factor (VEGF), compared with cells alone. Control polycaprolactone (PCL) spheres failed to stimulate a similar prolonged increase in VEGF secretion. An enhanced angiogenic effect was also seen in vivo using the chick embryo chorioallantoic membrane assay, where a significant increase in the number of blood vessels converging towards collagen spheres was observed compared with control PCL spheres. The results from this study indicate that microporous collagen spheres produced using TIPS are biologically active and could offer a novel conformable scaffold for tissue regeneration in poorly accessible wounds.