The efficacy of anal fistula plug in fistula-in-ano: a systematic review

Biomaterials in the treatment of anal fistula: hope or hype?

Anal fistula (AF) presents a chronic problem for patients and colorectal surgeons alike. Surgical treatment may result in impairment of continence and long-term risk of recurrence. Treatment options for AFs vary according to their location and complexity. The ideal approach should result in low recurrence rates and minimal impact on continence. New technical approaches involving biologically derived products such as biological mesh, fibrin glue, fistula plug, and stem cells have been applied in the treatment of AF to improve outcomes and decrease recurrence rates and the risk of fecal incontinence. In this review, we will highlight the current evidence and describe our personal experience with these novel approaches.

A newly designed anal fistula plug: clinicopathological study in an experimental iatrogenic fistula model

We report on a clinicopathologic study in an animal model of treatment with a new bioabsorbable polymer plug (BAPP). Over a 2-week period, 6 porcine models, which each had 4 anal fistulae, were created using Blake drains. The pigs were divided into 2 groups: the BAPP-treatment group (n = 12 fistulae) and the control group (n = 12 fistulae). Two weeks later, the pigs were humanely killed, and the perianal sites were excised and examined with gross and pathologic studies. Each fistula in the BAPP group was completely cured. In the pathologic study, the treatment sites had little disarray, few defects in the muscular layer, and small numbers of inflammatory cells. The control group had a significantly greater number of inflammatory cells and microabscesses than the BAPP group. The newly developed BAPP reduced the infection and induced good healing in anal fistulae. The BAPP may be a useful new device for the clinical treatment of anal fistulae.

Treatment of peri-anal fistula in Crohn's disease

Anal fistulas are a common manifestation of Crohn’s disease (CD). The first manifestation of the disease is often in the peri-anal region, which can occur years before a diagnosis, particularly in CD affecting the colon and rectum. The treatment of peri-anal fistulas is difficult and always multidisciplinary. The European guidelines recommend combined surgical and medical treatment with biologic drugs to achieve best results. Several different surgical techniques are currently employed. However, at the moment, none of these techniques appear superior to the others in terms of healing rate. Surgery is always indicated to treat symptomatic, simple, low intersphincteric fistulas refractory to medical therapy and those causing disabling symptoms. Utmost attention should be paid to correcting the balance between eradication of the fistula and the preservation of fecal continence.

Results of collagen plug occlusion of anal fistula: a multicentre study of 126 patients

AIM

The Biodesign(®) anal fistula plug was introduced as a means of obliterating the fistula tract and promoting healing through biocompatibility. The results demonstrated unexplained variations from good to bad. This report analysed the results of a retrospective multicentre study.

METHOD

All plug procedures performed in four Stockholm hospitals between June 2006 and June 2010 were identified and studied using a common protocol. The outcome after the first plug-insertion procedure was assessed by chart review performed a minimum of 8 months after plug insertion. Cox proportional-hazards models were used to assess the associations of various factors with fistula healing.

RESULTS

One-hundred and twenty-six patients (mean age 47 years) were deemed suitable for the plug procedure. Eighty-five per cent of fistulae were cryptoglandular, 64% of patients were male and a mean of 2.9 previous fistulae procedures had been performed. All patients, except four, had an indwelling seton at the time of the plug procedure, which was performed in accordance with previously established principles of day surgery. After a median of 13 months, 30 (24%) fistulae had closed with no discomfort or secretion reported. The outcome in the four hospitals varied from 13% to 33% with similar numbers of patients in each hospital. A success rate of 12% was observed for patients with anterior fistula compared with 32% for those with posterior tracks [hazard ratio (HR) for successful healing = 2.98; 95% CI: 1.01-8.78) and 41% for those with a lateral internal opening (HR = 3.76; 95% CI: 1.03-13.75). Age, sex and number of previous procedures were not associated with healing.

CONCLUSION

Four independent patient groups showed low success rates after the first plug-insertion procedure. Anterior fistulae were much less likely to heal compared with fistulae in other locations.

Ligation of intersphincteric fistula tract (LIFT) to treat anal fistula: systematic review and meta-analysis

Sphincter-preserving approaches to treat anal fistula do not jeopardize continence; however, healing rates are suboptimal. In this context, ligation of the intersphincteric fistula tract (LIFT) can be considered promising offering high success rates and a relatively simple procedure. This review aimed to investigate the outcomes of LIFT to treat anal fistula. We conducted a systematic review of the Pubmed, Web of Science, and Cochrane databases, to retrieve all relevant scientific original articles and scientific abstracts (Web of Science) related to the LIFT procedure for anal fistula between January 2007 and March 2013. The search yielded 24 original articles including 1,110 patients; these included one randomized controlled study, three case control studies, and 20 case series. Most studies included patients with trans-sphincteric or complex fistula, not amenable to fistulotomy. During a pooled mean 10.3 months of follow-up, the mean success, incontinence, intraoperative, and postoperative complication rates were 76.4, 0, 0, and 5.5%, respectively. A sensitivity analysis showed that the impact on success in terms of follow-up duration, study size, and combining other procedures was limited. There was no association between pre-LIFT drainage seton and success of LIFT. Ligation of the intersphincteric fistula tract appears to be an effective and safe treatment for trans-sphincteric or complex anal fistula. Combining other procedures and a pre-LIFT drainage seton does not seem to confer any added benefit in terms of success. However, given the lack of prospective randomized trials, interpretation of these data must be cautious. Further trials are mandatory to identify predictive factors for success, and true effectiveness of the LIFT compared to other sphincter-preserving procedures to treat anal fistula.

Improving the outcome of fistulising Crohn's disease

Fistulas are a frequent manifestation of Crohn's disease (CD) and can result in considerable morbidity. Approximately 35% of all patients with CD will experience one fistula episode during their disease course of which 54% is perianal. The major symptoms of patients with perianal fistulas are constant anal pain, the formation of painful swellings around the anus and continuous discharge of pus and/or blood from the external fistula opening. The exact aetiology of perianal fistulas in CD patients remains unclear, but it is thought that a penetrating ulcer in the rectal mucosa caused by active CD forms an abnormal passage between the epithelial lining of the rectum and the perianal skin. Genetic, microbiological and immunological factors seem to play important roles in this process. Although the incidence of perianal fistulas in patients with CD is quite high, an effective treatment is not yet discovered. In this review all available medical and surgical therapies are discussed and new treatment options and research targets will be highlighted.

Ligation of intersphincteric fistula tract for treatment of complex anal fistula

Ligation of intershpincteric fistula tract (LIFT) is a novel surgical procedure for complex fistula, especially transsphincteric fistula which was first proposed by Thailand doctor Rojanasakul.This sphincter-saving procedure has a high success rate, and more importantly, a very low continence rate. Recent clinical research of LIFT has showed that its efficacy varies greatly. In this article, we will review the recent advances in research on ligation of intershpincteric fistula tract for complex anal fistula.

Bioabsorbable synthetic plug in the treatment of anal fistulas

BACKGROUND

Management of anal fistulas is challenging, because surgeons must aim to obtain complete healing while sparing the sphincter and avoiding fecal incontinence. The optimal treatment method remains unknown.

OBJECTIVE

This study assessed the safety and effectiveness of the use of a new synthetic fistula plug made of bioabsorbable polymers in the treatment of cryptoglandular anal fistulas.

DESIGN

This study is a retrospective review of a database of patient records.

SETTING

: Patients were treated at a general hospital in Italy.

PATIENTS

Forty-eight patients (39 men and 9 women; mean age, 49.9 years) with 49 fistulas were treated with the synthetic plug between November 2009 and March 2012. Types of fistula were as follows: 24 superficial transsphincteric, 18 medium transsphincteric, 5 deep transsphincteric, and 1 medium intersphincteric.

INTERVENTIONS

The fistula tract was cleaned by using curettage, and a synthetic plug was sized to fit the tract and inserted. A draining seton was used preoperatively in 1 patient.

MAIN OUTCOME MEASURES

The outcome measures were complete closure of the fistula, with no discharge/residual fistula (verified by endoanal ultrasonography), perineal pain level (assessed with a visual analog scale), and fecal continence. Follow-up was conducted at 1 week and 1, 3, 6, and 12 months postoperatively.

RESULTS

The overall healing rate was 69.3% (34/49 fistulas, 33/48 patients). Eight patients (24.2%) had healing by 3 months after surgery, 21 patients (63.6%) had healed by 6 months, and 4 patients (12.1%) had healed by 12 months. By 3 months, no patient had perineal pain or fecal incontinence. No plug became dislodged, and no patient had the onset of anal stenosis, bleeding, local infection, or any other complication.

LIMITATIONS

The number of patients and the retrospective nonrandomized nature of the investigation are limitations of this study.

CONCLUSIONS

In patients with cryptoglandular anal fistulas, the use of a bioabsorbable synthetic plug provided a high rate of healing without causing fecal incontinence or other major adverse effects. Larger and randomized studies of this treatment are warranted.

Surgical treatment of anorectal crohn disease

Crohn disease involves the perineum and rectum in approximately one-third of patients. Symptoms can range from mild, including skin tags and hemorrhoids, to unremitting and severe, requiring a proctectomy in a small, but significant, portion. Fistula-in-ano and perineal sepsis are the most frequent manifestation seen on presentation. Careful diagnosis, including magnetic resonance imaging or endorectal ultrasound with examination under anesthesia and aggressive medical management, usually with a tumor necrosis factor-alpha, is critical to success. Several options for definitive surgical repair are discussed, including fistulotomy, fibrin glue, anal fistula plug, endorectal advancement flap, and ligation of intersphincteric fistula tract procedure. All suffer from decreased efficacy in patients with Crohn disease. In the presence of active proctitis or perineal disease, no surgical therapy other than drainage of abscesses and loose seton placement is recommended, as iatrogenic injury and poor wound healing are common in that scenario.

The treatment of anal fistulas with biologically derived products: is innovation better than conventional surgical treatment? An update

New technical approaches involving biologically derived products have been applied in the treatment for anal fistulas in order to avoid the risk of fecal incontinence. The aim of this review was to evaluate the scientific evidence present in the literature regarding these techniques. Trials comparing surgery (fistulotomy, advancement mucosal flap closure and placement of seton) versus fibrin glue, fistula plug or acellular dermal matrix were considered. In fibrin glue versus traditional surgical treatment the healing rate was higher in the surgery group, and the recurrence rate was lower in the traditional surgery group, but these results were not statistically relevant. In acellular dermal matrix (ADM) versus traditional surgical treatment the recurrence rate of fistulas was significantly lower in the ADM group, but non-significant differences were recorded in incontinence and anal deformity. Our review shows that there are no significant advantages of the new techniques involving biologically derived products. Further randomized controlled trials are needed.

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.

Collagen matrix injection combined with flap repair for complex anal fistula

Several biomaterials have been proposed to treat anal fistula alone or in combination with other surgical procedures aiming to reduce recurrence rates while minimizing continence impairment. More recently a porcine dermal matrix injection has been proposed as infill biomaterial to treat fistulae. We propose an approach consisting of non-cutting seton positioning followed several weeks later by flap repair associated with dermal matrix injection into the fistula tracts. We report our experience with this two-staged procedure on 24 consecutive patients with complex anal fistulae with a median follow up of > 12 months. In our experience this two-stage approach seems to be safe and effective.

Anal fistula plug vs mucosa advancement flap in complex fistula-in-ano: A meta-analysis

AIM: To investigate the efficacy of the anal fistula plug (AFP) compared to the mucosa advancement flap (MAF), considered the best procedure for patients with a complex anal fistula.

METHODS: The literature search included PubMed, EMBASE, Cochrane Library and OVID original studies on the topic of AFP compared to MAF for complex fistula-in-ano that had a deadline for publication by April 2011. Randomized controlled trials, controlled clinical trials and prospective cohort studies were included in the review. After information collection, a meta-analysis was performed using data on overall success rates as well as incidence of incontinence and morbidity. The quality of postoperative life was also included with the clinical results.

RESULTS: Six studies involving 408 patients (AFP = 167, MAF = 241) were included in the meta-analysis. The differences in the overall success rates and incidence of fistula recurrence were not statistically significant between the AFP and MAF [risk difference (RD) = -0.12, 95%CI: -0.39 - 0.14; RD = 0.13; 95%CI: -0.18 - 0.43, respectively]. However, for the AFP, the risk of postoperative impaired continence was lower (RD = -0.08, 95%CI: -0.15 - -0.02) as was the incidence of other complications (RD = -0.06, 95%CI: -0.11 - -0.00). The postoperative quality of life, for patients treated using the AFP was superior to that of the MAF patients. Patients treated with the AFP had less persistent pain of a shorter duration and the healing time of the fistula and hospital stay were also reduced.

CONCLUSION: The AFP is an effective procedure for patients with a complex anal fistula; it has the same success rate but a lower risk of complications than the MAF and may also be associated with an improved postoperative quality of life. Additional evidence is needed to confirm these findings.

Gore BioA Fistula Plug in the treatment of high anal fistulas--initial results from a German multicenter-study

Background: Treatment of high anal fistulas may be associated with a high risk of continence disorders. Beside traditional procedure of flap-reconstruction the occlusion of the fistula tract using fistula-plugs offers a new sphincter-saving treatment option. In this study for the first time results from Germany are described.

Patients and method: 40 patients (30 male, 10 female, age 51±12 years) underwent closure of a high trans-sphincteric (n=28) or supra-sphincteric (n=12) fistula with Gore BioA Fistula Plug^® in three surgical departments. The surgical procedures had been performed by five colorectal surgeons. Four patients had Crohn’s disease. Preoperatively 33 patients were completely continent; seven patients complained of minor continence disorders. Treatment of the patients was performed on a intent-to-treat basis and evaluation of the results was retrospective using pooled data from each center.

Results: Postoperatively one patient developed an abscess, which had to be managed surgically. In two patients the plug had fallen out within the first two weeks postoperatively. Six months after surgery the fistula has been healed in 20 patients (50.0%). Three additional fistulas healed after 7, 9 rsp. 12 months. The overall healing-rate was 57.5% (23/40). The healing rate differs considerably between the surgeons from 0 to 75% and depends on the number of previous interventions. In patients having only drainage of the abscess success occurred in 63.6% (14/22) whereas in patients after one or more flap fistula reconstruction the healing rate decreased slightly to 50% (9/18). No patient complained about any impairment of his preoperative continence status.

Conclusion: By occlusion of high anal fistulas with a plug technique definitive healing could be achieved in nearly every second patients. Previous surgery seems to have a negative impact on success rate. We have not observed any negative impact on anal continence. From that point of view anal fistula plugs might be discussed as a treatment option for high anal fistulas, but further studies are needed to gain conclusive evidence.

Total fistulectomy with simple closure of the internal opening in the management of complex cryptoglandular fistulas: long-term results and functional outcome

BACKGROUND

Total fistulectomy with simple closure of the internal opening has been used for the management of complex anal fistulas. This approach involves complete removal of the fistula tract and closure of the internal opening with sutures.

OBJECTIVE

This study aimed to report long-term outcomes in patients with complex cryptoglandular fistulas who undergo this procedure.

DESIGN

This is a retrospective review of a prospectively collected consecutive series.

SETTINGS

This study was conducted at a community-based hospital with a specialized colorectal unit.

PATIENTS

: Patients included in this study had cryptoglandular fistulas and underwent total fistulectomy with simple closure of the internal opening between 1997 and 2007.

MAIN OUTCOME MEASURES

The main outcome measures were success rate and postoperative continence (Cleveland Clinic Florida Fecal Incontinence Scale). Treatment was considered successful if the external opening was closed and no drainage was present at the last follow-up.

RESULTS

Success was achieved in 187 (74%) patients with a median follow-up time of 70 (range, 14-141) months. Patients with posterior transsphincteric or suprasphincteric fistulas had a higher success rate than those with other types of fistulas (82% vs 67%;p = 0.014), and patients for whom the procedure failed were significantly younger than those for whom the procedure was a success (mean, 45 vs 50 years; p = 0.010). Of 160 patients with success who had no previous surgery, 89 (56%) had normal continence postoperatively (CCF-FI score = 0).

LIMITATIONS

The limitations of this study include its retrospective nature, the potential for selection bias, and the lack of preoperative continence scores.

CONCLUSIONS

Total fistulectomy with simple closure of the internal opening is effective for the long-term closure of complex cryptoglandular fistulas.However, this procedure may affect continence despite its sphincter-sparing quality. Nonetheless, the high success rate in patients with posterior transsphincteric or suprasphincteric fistulas renders this procedure a reasonable option in this subgroup of patients with complex fistulas.

A systematic review of the anal fistula plug for patients with Crohn's and non-Crohn's related fistula-in-ano

BACKGROUND

The management of fistula-in-ano is a balance between fistula cure and preservation of continence.

OBJECTIVE

The aim of this study is to summarize the anal fistula plug literature for Crohn's and non-Crohn's fistula-in-ano in a homogenous patient population.

DATA SOURCES

PubMed, MEDLINE, Embase, and Cochrane medical databases were searched from 1995 to 2011. Abstracts from The American Society of Colon and Rectal Surgeons, The Society for Surgery of the Alimentary Tract, The European Society of Coloproctology, and the Association of Coloproctology of Great Britain and Ireland meetings between 2007 and 2010 were also evaluated.

STUDY SELECTION

Studies were included if results for patients with and without Crohn's disease could be differentiated. Patients with rectovaginal, anovaginal, rectourethral, or ileal-pouch vaginal fistulas were excluded as were studies where the mean or median follow-up was less than 3 months. Two researchers independently selected studies matching the inclusion criteria.

INTERVENTION

Anal fistula plug insertion was performed.

MAIN OUTCOME MEASURES

The primary outcomes measured were the overall fistula closure rates and length of follow-up.

RESULTS

Seventy-six articles or abstracts were identified from the title as being of relevance. Twenty studies (2 abstracts, 18 articles) were finally included. Study sample size ranged from 4 to 60 patients; 530 patients were included in all studies (488 non-Crohn's and 42 Crohn's patients). The plug extrusion rate was 8.7% (46 patients). The proportion of patients achieving fistula closure varied widely between studies for non-Crohn's, ranging from 0.2 (95% CI 0.04-0.48) to 0.86 (95% CI 0.64-0.97). The pooled proportion of patients achieving fistula closure in patients with non-Crohn's fistula-in-ano was 0.54 (95% CI 0.50-0.59). The proportion achieving closure in patients with Crohn's disease was similar (0.55, 95% CI 0.39-0.70).

LIMITATIONS

This study was limited by the variability of operative technique and perioperative care between studies.

CONCLUSIONS

Fistula closure is achieved by using the anal fistula plug in approximately 54% of patients without Crohn's disease. The anal fistula plug has not been adequately evaluated in the Crohn's population.

Long-term results of surgery plus fibrin sealant for anal fistula

AIM

The long-term recurrence rate of fibrin glue treatment was analysed in patients with trans-sphincteric cryptoglandular fistula operated by a two-phase procedure: (i) fistulectomy with seton placement; (ii) fibrin sealant (Tissucol Duo®, Baxter) insertion in the track.

METHOD

Clinical data were collected prospectively for all patients operated between 2004 and 2010. The statistical association of clinical variables and recurrence was analysed and a disease-free curve was constructed using the Kaplan-Meier method.

RESULTS

Twenty-eight consecutive patients (mean age 48.3 ± 13.3 years; 22 men) were enrolled in the study. Middle and high trans-sphincteric fistulae were diagnosed in 20 (71.4%) and eight (28.6%) patients. Seven (25%) had secondary track formation. The mean interval between the first operation and the fibrin sealant treatment was 12.5 ± 7.6 months. There were no complications related to the procedure. Nine (32.1%, 95% CI 17.9-50.7%) patients developed recurrence between 3 and 27 months after fibrin sealant treatment. Disease-free curves showed that the highest probability of recurrence occurred in the first 2 years. No incontinence was found at a mean follow-up of 20.6 (3-60) months among the 67.8% patients with no evidence of recurrence.

CONCLUSION

Fibrin sealant is safe and simple. The healing rate is satisfactory without the risk of incontinence.

Cryptoglandular anal fistulas

BACKGROUND

Cryptoglandular anal fistula arises in 2 per 10 000 persons per year and is most common in young men. Improper treatment can result in fecal incontinence and thus in impaired quality of life.

METHOD

This S3 guideline is based on a systematic review of the pertinent literature.

RESULTS

The level of evidence for treatment is low, because relevant randomized trials are scarce. Anal fistulae are classified according to the relation of the fistula channel to the sphincter. The indication for treatment is established by the clinical history and physical examination. During surgery, the fistula should be probed and/or dyed. Endo-anal ultrasonography and magnetic resonance imaging are of roughly the same diagnostic value and may be useful as additional studies for complex fistulae. Surgical treatment is with one of the following operations: laying open, seton drainage, plastic surgical reconstruction with suturing of the sphincter, and occlusion with biomaterials. Only superficial fistulae should be laid open. The risk of postoperative incontinence is directly related to the thickness of sphincter muscle that is divided. All high anal fistulae should be treated with a sphincter-saving procedure. The various plastic surgical reconstructive procedures all yield roughly the same results. Occlusion with biomaterials yields a lower cure rate.

CONCLUSION

This is the first German S3 guideline for the treatment of cryptoglandular anal fistula. It includes recommendations for the diagnostic evaluation and treatment of this clinical entity.