Is the ligation of the intersphincteric fistula tract (LIFT) procedure truly a sphincter preserving procedure for anal fistula? A scoping review of the literature

INTRODUCTION: The ligation of the intersphincteric fistula tract (LIFT) procedure has garnered popularity with its success rates and purported sphincter-continence preservation. However, there remains a paucity in the literature on the objective evaluation of sphincter integrity and fecal continence after the LIFT procedure. OBJECTIVES: The present study undertakes a scoping review to systematically explore and map the published literature, to evaluate the sufficiency of data on the impact on continence in patients after the LIFT procedure. DESIGN: A systematic search of MEDLINE, PubMed, EMBASe, CINAHL was performed from January 2007 to April 2020 and 597 publications were identified. Forty-two satisfied the inclusion and exclusion criteria. We performed a scoping review in accordance to the PRISMA-ScR guidelines. RESULTS: Only 3 (7.1%) of publications were randomized controlled trials, of which just 1 (2.4%) measured incontinence as a primary outcome. Continence was measured both pre- and post-LIFT in 30 (71.4%), of which 19 (45.2%) had a fixed protocol for continence assessment, which was heterogeneous between the studies. Continence was assessed using subjective scoring systems in 27 (64.3%) and objective measurement was performed in just 6 (14.3%). No studies performed post-operative anatomical assessment of the anal sphincter complex. CONCLUSIONS: Long-term continence in post-LIFT patients is not supported with adequately powered prospective longitudinal trials using rigorously protocoled pre- and post-operative assessment of continence. Future research that focuses on a combination of objective assessment using anal manometry as well as anatomical assessment of the sphincter complex on top of subjective evaluation is needed before we can be certain if LIFT is indeed a sphincter and continence preserving technique.