A Multicenter Randomized Controlled Trial Comparing Safety, Efficacy, and Cost-effectiveness of the Surgisis Anal Fistula Plug Versus Surgeon's Preference for Transsphincteric Fistula-in-Ano: The FIAT Trial

OBJECTIVE:To undertake a randomized comparison of the Biodesign Surgisis anal fistula plug against surgeonʼs preference in treating cryptoglandular transsphincteric fistula-in-ano. SUMMARY BACKGROUND DATA:The efficacy of the Biodesign Surgisis anal fistula plug in healing anal fistulae is uncertain. METHODS:Participants were randomized to the fistula plug with surgeonʼs preference (advancement flap, cutting seton, fistulotomy, Ligation of the Intersphincteric Fistula Tract procedure). The primary outcome was faecal incontinence quality of life (FIQoL) at 12-months. Secondary outcomes were fistula healing, incontinence rates, and complication and reintervention rates. RESULTS:Between May 2011 and March 2016, 304 participants were randomized to fistula plug or surgeonʼs preference. No differences were seen in FIQoL between the 2 groups at 12 months. Clinical fistula healing was reported in 66/122 (54%) of the fistula plug and 66/119 (55%) of the surgeonʼs preference groups at 12 months. Fecal incontinence rates improved marginally in both the groups. Complications and reinterventions were frequent, with significantly more complications in the fistula plug group at 6-weeks (49/142, 35% vs 25/137, 18%; P=0.002). The mean total costs were £2738 (s.d. £1151) for the fistula plug and £2308 (s.d. £1228) for the surgeonʼs preference group (mean difference +£430, P=0.0174). The average total quality adjusted life years (QALYs) gained was marginally higher in the fistula plug group. The fistula plug was 35% to 45% likely to be cost-effective across a willingness to pay threshold of £20,000 to £30,000 / QALY. CONCLUSIONS:The Biodesign Surgisis anal fistula plug is associated with similar FIQoL and healing rates to surgeonʼs preference at 12 months. Higher costs and highly uncertain gains in QALYs mean that the fistula plug may not be considered as a cost-effective treatment in the UK NHS.