Archived Policies - Surgery

Plugs for Fistula Repair


Effective Date:01-01-2014

End Date:04-14-2015


Biosynthetic fistula plugs, including plugs made of porcine small intestine submucosa or of synthetic material, are considered experimental, investigational and/or unproven for all indications including, but not limited to, repair of anal and rectal fistulas.


An anal fistula is an abnormal communication between the interior of the anal canal or rectum and the skin surface. Rarer forms may communicate with the vagina or other pelvic structures, including the bowel. Most fistulas begin as anorectal abscesses. When the abscess opens spontaneously into the anal canal (or has been opened surgically), a fistula may occur. Other causes of fistulas include tuberculosis, cancer, and inflammatory bowel disease. Fistulas may occur singly or in multiples. Symptoms include a purulent discharge and drainage of pus and/or stool near the anus, which can irritate the outer tissues causing itching and discomfort. Pain occurs when fistulas become blocked and abscesses recur. Flatus may also escape from the fistulous tract. Anal fistulas are described as low (present distally and not extending up to the ano-rectal sling) or high (extending up to or beyond the ano-rectal sling). High fistulas can be associated with incontinence. Diagnosis may involve a fistula probe, anoscopy, fistulography, ultrasound, or magnetic resonance imaging (MRI). Treatment is aimed at repairing the fistula without compromising continence. Treatments include fistulotomy/fistulectomy, endorectal/anal sliding flaps, seton drain, and fibrin glue. Lay-open fistulotomy in high fistulas carries the risk of incontinence. Draining setons can control sepsis, but few patients heal after removal of the seton, and they are poorly tolerated long term. Cutting setons can cause continence disturbances.

The SIS Fistula Plug from Cook Biotech received 510(k) clearance from the U.S. Food and Drug Administration (FDA) in March 2005 based on similarity to predicate devices, including the SURGISIS® Soft Tissue Graft and the STRATASIS® Urethral Sling, both manufactured by Cook Biotech Incorporated. The SIS Fistula Plug is manufactured from porcine small intestinal submucosa (SIS) and is intended for repair of anal, rectal, and enterocutaneous fistulas. The modified SIS Fistula Plug, also manufactured from SIS, is supplied in a tapered configuration with a button to provide increased retention of the plug and improved blockage of the fistula. It received 510(k) clearance in October 2006. In March 2009, W.L. Gore & Associates received 510(k) clearance for the BIO-A® Fistula Plug intended for use in anorectal fistulas. The GORE BIO-A Fistula Plug device comprises a porous structure of synthetic bioabsorbable PGA/TMC copolymer fiber, degraded via a combination of hydrolytic and enzymatic pathways, using the same material, technology, and 3-dimensional disk with tubes mesh design as the predicate GORE Bioabsorbable Mesh hernia plug device. The indications for use and performance of the GORE BIO-A™ Fistula Plug are substantially equivalent to the predicate Cook SIS Fistula Plug.


This policy was created in 2007 and regularly updated with searches of the MEDLINE database. The most recent literature search was performed through August 28, 2013.

Conventional treatments for anal fistulas include fistulotomy/fistulectomy, endorectal/anal sliding flaps, seton drains, and fibrin glue. Evidence for new treatments must allow comparison with conventional treatment on outcomes including safety, healing, fistula recurrence, and sphincter function.

There are limited published prospective, comparative data on outcomes of anal fistula plug (AFP) procedures. Searches of the MEDLINE database found 2 randomized controlled trials (RCTs) and several prospective case series and retrospective comparative studies.

Systematic Reviews

At least 5 systematic reviews have been undertaken on AFP. In 2012, 3 reviews were published comparing AFP to conventional surgical treatment for anal fistulas. (1-3) Pu and colleagues undertook a meta-analysis of 5 studies (2 RCTs and 3 retrospective studies) published through April 2012. Treatment options in the conventional arm of this review included endorectal/mucosal advancement flaps, fibrin glue, and seton drains. (1) The 2 RCTs included in this analysis (Ortiz, 2009; van Koperen, 2011) are discussed below under randomized controlled trials. On combined analysis, AFP patients had a higher recurrence rate (62%) compared to those undergoing conventional treatment options (47%) after 3 months of follow-up (5 studies, 428 patients; p=0.004, odds ratio [OR]: 1.91; 95% confidence interval [CI]: 1.23-2.97).

Leng and Jin undertook a meta-analysis of 6 studies published through April 2011 (3 RCTs, 2 retrospective studies, and one cohort study) involving 408 patients comparing AFP with mucosal advancement flap (MAF). (2) Two of the RCTs in this analysis were included in the review by Pu and colleagues above; the third RCT was a Chinese trial of 90 patients comparing AFP (manufactured in China and similar in design to the SURGISIS®) to the MAF. On combined analysis, the differences in the overall success rates (6 studies) and incidence of fistula recurrence (4 studies including 3 RCTs) 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). (2) The risk of continence postoperatively (3 studies including 2 RCTs), however, was reported to be lower with AFP (RD: -0.08; 95% CI: 0.15 to -0.02). In addition to the small numbers of controlled studies and limited follow-up, the findings of this meta-analysis were further limited by significant heterogeneity across studies. (2)

O’Riordan and colleagues undertook a systematic review of AFP (20 studies including 2 RCTs by Ortiz and van Koperan) for patients with Crohn’s and non-Crohn’s-related anal fistulas. (3) The follow-up period across studies ranged from 3 months to 24.5 months. The pooled proportion of patients achieving fistula closure in patients with non-Crohn’s anal fistula 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). (3) There were no reported cases of any significant change in continence after AFP insertion in any of the study patients (n=196). The findings of this systematic review are limited by the variability of operative technique and perioperative care across studies, which may influence the probability of success or failure associated with the AFP. (3)

A 2010 systematic review reports a wide range of success rates. (4) In the 12 case series included in the review, reported success rates for the AFP procedure ranged from 24% to 92%. Success rates in treating complex fistula-in-ano in the 8 prospective studies reviewed were 35% to 87%. The complications of abscess formation and/or sepsis ranged from 4% to 29%, and plug extrusion ranged from 4%-41%.

In a Cochrane review of surgical intervention for anorectal fistula, Jacob and colleagues found few randomized trials comparing procedures for surgical repair. (5) Anal fistula plug was one procedure noted as needing further study with randomized trials.

Randomized controlled trials

Ortiz and colleagues, in a European trial, compared use of porcine submucosal (Surgisis) AFP with an endorectal anal flap (ERAF) procedure in an RCT with 43 patients with high anal fistula. (6) The primary endpoint was fistula healing. Recurrence was defined as the presence of an abscess in the same area or obvious evidence of fistulization. Five patients in the AFP group and 6 in the ERAF group did not receive the allocated intervention, leaving 32 patients. One patient in the AFP group was lost to follow-up. A large number of recurrences in the fistula plug group led to premature closure of the trial. After 1 year, fistula recurrence was seen in 12 of 15 patients treated with an AFP versus 2 of 16 patients who underwent the flap procedure (relative risk [RR]: 6.40; 95% confidence interval [CI]:1.70-23.97]); p<0.001). Fistulas recurred in 9 of 16 patients who had previously undergone fistula surgery; 8 of the 9 patients had an AFP. A trend for more sphincter involvement and more females in the ERAF group was noted. Complications were not reported in this paper.

Van Koperen and colleagues reported on a double-blinded, multicenter, randomized trial comparing AFP with mucosal advancement flap in 60 patients with high perianal fistulas. (7) At 11 months follow-up, the authors reported fistula recurrence in 22 patients (71%) in the AFP group and 15 patients (52%) in the advancement flap group; these rates were not significantly different (p=0.126). Postoperative pain scores, quality of life after surgery and functional outcomes were not significantly different between groups. Despite disappointing results, the authors indicated the plug might be considered as an initial treatment option because the plug procedure is simple and minimally invasive.

Non-randomized comparative studies

Hyman et al. reported on prospective, multicenter registry outcomes data to compare a variety of procedures to treat anal fistulas in 245 patients at 13 hospitals. (8) Data were collected as part of a prospective, multicenter outcomes registry created by colorectal surgeons in parts of New England. Fistulotomy was the most frequently performed procedure (n=120) followed by fistula plug (n=43), staged fistulotomy (n=36), seton drain only (n=21), cutting seton (n=13), fibrin glue (n=5), and advancement flap (n=4). Three other patients were listed as other or unrecorded. At 1 month and 3 months, 19.5% and 63.2% of patients were healed, respectively. At 3 months, 32% of fistula plug patients were healed in comparison to 87% of fistulotomy, 50% of staged fistulotomy, and 5% of seton drain-only patients. The authors noted limitations to this registry-based study including concerns about data entry, lack of standardized surgical procedures, and heterogeneity of patients. The 3-months’ results may also indicate longer healing times may be needed.

Christoforidis et al. performed a retrospective analysis of patients from a U.S. center with transsphincteric fistulas treated with ERAF (n=43) or anal plug (Surgisis) (n=37) between January 1996 and April 2007. (9) Success was defined as closed external opening in absence of symptoms at minimal follow-up of 6 months. The success rate was 63% in the ERAF group and 32% in the in AFP group after a mean follow-up of 56 (range, 6–136) months for ERAF and 14 (range, 6–22) months for AFP. After exclusion of patients with early AFP extrusion, which may be considered a technical failure, the ERAF advantage did not meet statistical significance (p=0.06). Twenty-three of 27 patients who had ERAF and 7 of 12 patients who had AFP responded to a questionnaire addressing functional outcomes. In the ERAF group, 11 of 23 patients had no continence disturbance versus 6 of 7 in the AFP group. The lack of prospectively collected incontinence scores prior to the procedure and low response rate in the AFP group prohibit valid comparisons on functional outcomes. Complication rates were low in both groups; 2 patients in the ERAF group required reoperation for bleeding. No serious complications occurred in the AFP group. The authors conclude that “randomized trials are needed to further elucidate the efficacy and potential functional benefit of AFP in the treatment of complex anal fistulas.”

Wang et al. compared outcomes of all patients with transsphincteric fistulas treated with AFP from July 2005 to December 2006 (n=29) and compared them with historical controls treated with ERAF (2001–2005) (n=26). (10) Of 26 initial flap procedures, 10 failed and 16 healed. Of 29 initial plug procedures, 19 failed and 10 healed. In total, 30 advancement flaps and 34 plug procedures were performed (including the additional treatments for failed initial procedures). Closure rates were 34% for plugs (mean follow-up 279 days [range, 110–690]) and 62% for flaps (median follow-up 819 days [range, 93–1,928]; p=0.045). Complications were not reported. The authors conclude that a systematic randomized trial with long-term follow-up comparing advancement flaps with fistula plugs is needed, and they calculate that 112 patients would need to be randomized to detect a statistically significant difference in success rates for each procedure. Because the fistula plugs are costly, the authors recommend that cost-benefit analysis be performed.

A retrospective study of 232 patients treated in Canada between 1997 and 2008 by a variety of methods for high transsphincteric anal fistulas was reported by Chung et al. (11) Postoperative healing rates at the 12-week follow-up for the fistula plug, fibrin glue, flap advancement, and seton drain groups were 59.3%, 39.1%, 60.4%, and 32.6%, respectively. They conclude that closure of the primary fistula opening using a biologic AFP and anal flap advancement result in similar fistula healing rates in patients with high transsphincteric fistulas and that these strategies are superior to seton placement and fibrin glue. “Given the low morbidity and relative simplicity of the procedure, the anal fistula plug is a viable alternative treatment for patients with high transsphincteric anal fistulas.” The 12-week follow-up time in this study is likely too short to evaluate the durability of treatment.

Other papers report treatment of very small numbers of patients with rectovaginal fistulas, endoscopic treatment of postoperative enterocutaneous fistulas after bariatric surgery, a colocutaneous fistula, and a recurrent tracheoesophageal fistula treated with fistula plug.

Ongoing Clinical Trials

A search of online site identified at least 5 randomized controlled trials on anal fistula plugs. In NCT00830661, a biodegradable porcine anal fistula plug will be compared to ligation of the intersphincteric fistula tract (LIFT) procedure (LIFT vs. PLUG) in 124 randomized patients at 4 North American institutions. The estimated completion date of this trial was March 2012; however, its recruitment status is presently unknown because the information has not been verified as of May 2009. In another RCT, the SURGISIS® anal fistula plug will be compared to the advancement flap procedure in 86 randomized patients in Germany (NCT 00545441). This trial is completed, but not recruiting participants; study results have not been published.

The University of California, Los Angeles is conducting a trial to compare the SURGISIS® plug to cutting seton drain in 300 patients (NCT00450671). The estimated completion date of this trial was February 2012; however, its recruitment status is presently unknown because the information has not been verified as of March 2007. In NCT 01021774, an unspecified collagen plug will be compared to advancement flap in 100 randomized patients in Sweden. This trial is currently recruiting participants with an estimated completion date of December 2013. And finally, the LIFT procedure will be compared to LIFT combined with the anal fistula plug in China in 240 patients (NCT01478139). The estimated completion date of this trial was February 2013; however, its recruitment status is presently unknown because the information has not been verified as of November 2011.


Anal fistula plugs are biosynthetic devices used to promote healing and prevent recurrence of anal fistula. Evidence of efficacy of anal fistula plug treatment is quite limited. Available evidence reports a wide range of results and does not demonstrate that anal fistula plugs improve healing rates or reduce recurrence of anal fistulas. Randomized controlled trials that have sufficient numbers of patients with at least six months of follow-up, and that report healing, recurrence rates, and sphincter function before and after the procedure are required. In light of the limited data available and inconsistent outcomes reported, the impact on net health outcome is not known, and the use of anal fistula plugs is considered experimental, investigational and/or unproven.

Practice Guidelines and Position Statements

The 2011 Practice Parameters for the Treatment of Perianal Abscess and Fistula-in-Ano from the American Society of Colon and Rectal Surgeons gives treatment with an anal fistula plug for complex anal fistulas a weak recommendation. The guidelines note the available evidence is of moderate quality with success rates of less than 50% in the majority of studies. (12)

The National Institute for Health and Care Excellence (NICE) published an updated guidance on the suturable bioprosthetic plug in November 2011. (13) NICE determined that while there are no major safety concerns, evidence on the efficacy of the procedure is not adequate for it to be used without special arrangements for consent and for audit or research. Further, clinicians wishing to perform the procedure are encouraged to enroll patients into the Fistula-In-Ano Trial (FIAT) (Available online at: If the clinician chooses to perform the procedure outside of a clinical trial, the clinician should inform the clinical governance leads in their Trust, ensure that patients understand the uncertainty about the procedure’s efficacy and provide patients with clear written information (NICE recommends the information it developed for patients be provided) and audit and review clinical outcomes.


Each benefit plan, summary plan description or contract defines which services are covered, which services are excluded, and which services are subject to dollar caps or other limitations, conditions or exclusions. Members and their providers have the responsibility for consulting the member's benefit plan, summary plan description or contract to determine if there are any exclusions or other benefit limitations applicable to this service or supply. If there is a discrepancy between a Medical Policy and a member's benefit plan, summary plan description or contract, the benefit plan, summary plan description or contract will govern.




Disclaimer for coding information on Medical Policies

Procedure and diagnosis codes on Medical Policy documents are included only as a general reference tool for each policy. They may not be all-inclusive.

The presence or absence of procedure, service, supply, device or diagnosis codes in a Medical Policy document has no relevance for determination of benefit coverage for members or reimbursement for providers. Only the written coverage position in a medical policy should be used for such determinations.

Benefit coverage determinations based on written Medical Policy coverage positions must include review of the member’s benefit contract or Summary Plan Description (SPD) for defined coverage vs. non-coverage, benefit exclusions, and benefit limitations such as dollar or duration caps. 


The following codes may be applicable to this Medical policy and may not be all inclusive.

CPT Codes

43305, 43312, 44640, 46707, 57300, 57305, 57307, 57308



ICD-9 Diagnosis Codes

Experimental, investigational and /or unproven for all diagnoses

ICD-9 Procedure Codes

31.73, 46.74, 49.73, 70.73

ICD-10 Diagnosis Codes

Experimental, investigational and /or unproven for all diagnoses

ICD-10 Procedure Codes


Medicare Coverage:

The information contained in this section is for informational purposes only.  HCSC makes no representation as to the accuracy of this information. It is not to be used for claims adjudication for HCSC Plans.

The Centers for Medicare and Medicaid Services (CMS) does not have a national Medicare coverage position. Coverage may be subject to local carrier discretion.

A national coverage position for Medicare may have been developed since this medical policy document was written. See Medicare's National Coverage at <


  1. Pu YW, Xing CG, Khan I et al. Fistula plug versus conventional surgical treatment for anal fistulas. A system review and meta-analysis. Saudi Med J 2012; 33(9):962-6.
  2. Leng Q, Jin HY. Anal fistula plug vs mucosa advancement flap in complex fistula-in-ano: A meta-analysis. World J Gastrointest Surg 2012; 4(11):256-61.
  3. O'Riordan JM, Datta I, Johnston C et al. A systematic review of the anal fistula plug for patients with Crohn's and non-Crohn's related fistula-in-ano. Dis Colon Rectum 2012; 55(3):351-8.
  4. Garg P, Song J, Bhatia A et al. The efficacy of anal fistula plug in fistula-in-ano: a systematic review. Colorectal Dis 2010; 12(10):965-70.
  5. Jacob TJ, Perakath B, Keighley MR. Surgical intervention for anorectal fistula. Cochrane Database Syst Rev 2010; (5):CD006319.
  6. Ortiz H, Marzo J, Ciga MA et al. Randomized clinical trial of anal fistula plug versus endorectal advancement flap for the treatment of high cryptoglandular fistula in ano. Br J Surg 2009; 96(6):608-12.
  7. van Koperen PJ, Bemelman WA, Gerhards MF et al. The anal fistula plug treatment compared with the mucosal advancement flap for cryptoglandular high transsphincteric perianal fistula: a double-blinded multicenter randomized trial. Dis Colon Rectum 2011; 54(4):387-93.
  8. Hyman N, O'Brien S, Osler T. Outcomes after fistulotomy: results of a prospective, multicenter regional study. Dis Colon Rectum 2009; 52(12):2022-7.
  9. Christoforidis D, Pieh MC, Madoff RD et al. Treatment of transsphincteric anal fistulas by endorectal advancement flap or collagen fistula plug: a comparative study. Dis Colon Rectum 2009; 52(1):18-22.
  10. Wang JY, Garcia-Aguilar J, Sternberg JA et al. Treatment of transsphincteric anal fistulas: are fistula plugs an acceptable alternative? Dis Colon Rectum 2009; 52(4):692-7.
  11. Chung W, Kazemi P, Ko D et al. Anal fistula plug and fibrin glue versus conventional treatment in repair of complex anal fistulas. Am J Surg 2009; 197(5):604-8.
  12. Steele SR, Kumar R, Feingold DL et al. Practice parameters for the management of perianal abscess and fistula-in-ano. Dis Colon Rectum 2011; 54(12):1465-74.
  13. National Institutes for Health and Clinical Excellence (NICE). Closure of anal fistula using a suturable bioprosthetic plug. November 2011. Available online at: Last accessed May 2013.
  14. Plugs for Fistula Repair. Chicago, Illinois: Blue Cross Blue Shield Association Medical Policy Reference Manual. (September 2013). Surgery 7.01.123.

Policy History:

1/1/2014          Document updated with literature review. Coverage unchanged. CPT/HCPCS code(s) updated.

8/15/2011        Document updated with literature review. Coverage language changed as follows: Biosynthetic fistula plugs, including plugs made of porcine small intestine submucosa or of synthetic material are considered experimental, investigational and unproven for all indications including, but not limited to, repair of anal and rectal fistulas. Complete revision of description and rationale. Codes updated.

5/1/2009          Revised/updated entire document

2/15/2007        New medical document

Archived Document(s):

Title:Effective Date:End Date:
Plugs for Fistula Repair07-15-201803-31-2019
Plugs for Fistula Repair04-15-201707-14-2018
Plugs for Fistula Repair04-15-201604-14-2017
Plugs for Fistula Repair04-15-201504-14-2016
Plugs for Fistula Repair01-01-201404-14-2015
Plugs for Fistula Repair08-15-201112-31-2013
Anorectal Fistula Repair Using an Acellular Xenogeneic Plug05-01-200908-14-2011
Anorectal Fistula Repair Using an Acellular Xenogeneic Plug02-15-200704-30-2009
Anorectal Fistula Repair using an Acellular Xenogeneic Plug01-01-200702-14-2007
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