A multicentre randomised 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

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Colleges, School and Institutes


Objective: To undertake a randomised comparison of the Biodesign Surgisis® anal fistula plug against surgeon’s 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 randomised to the fistula plug with surgeon’s preference (advancement flap, cutting seton, fistulotomy, LIFT procedure). The primary outcome was faecal incontinence quality of life (FIQoL) at 12-months. Secondary outcomes were fistula healing, incontinence rates, and complication and re-intervention rates.

Results: Between May 2011 and March 2016, 304 participants were randomised to fistula plug or surgeon’s preference. No differences were seen in FIQoL between the two groups at 12-months. Clinical fistula healing was reported in 66/122 (54%) of the fistula plug and 66/119 (55%) of the surgeon’s preference groups at 12-months. Faecal incontinence rates improved marginally in both groups. Complications and re-interventions 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 £2,738 (s.d. £1,151) for the fistula plug and £2,308 (s.d. £1,228) for the surgeon’s preference group (mean difference +£430, p=0.0174). The average total QALYs gained was marginally higher in the fistula plug group. The fistula plug was 35% - 45% likely to be cost-effective across a willingness to pay threshold of £20,000-£30,000 / QALY.

Conclusions: The Biodesign Surgisis® anal fistula plug is associated with similar FIQoL and healing rates to surgeon’s 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.


Original languageEnglish
Pages (from-to)433-441
Number of pages9
JournalAnnals of surgery
Issue number3
Early online date9 Jun 2020
Publication statusPublished - Mar 2021