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.