EP1088 - How geography dictates management of complex anal fistula: a systematic review of literature

Purpose/Background: Managing complex anal fistula remains a significant surgical challenge. The choice of procedure differs widely across the world. In some countries, traditional operations such as cutting seton or fistulotomy are still frequently reported, whereas in others sphincter-preserving procedures or minimally invasive approaches dominate. The aim of this review is to map the global published experience from 2020 onwards, highlighting which procedures are commonly reported from each country and how these patterns reflect global regional practice.

Methods/Interventions: We reviewed English literature for the last 5 years, Jan 2020 and July 2025. PubMed was searched using the keywords "fistula," "fistula-in-ano," "anal," "rectal," "perianal," and "perineal" with the name of each country of interest. Randomized controlled trials, cohort studies, and prospective or retrospective studies and case series were reviewed. Data was extracted on study design, country of origin, sample size, and procedure type.

Results/Outcomes: Our PubMed search across 13 countries yielded 1,785 publications. 80 studies met inclusion criteria and were analyzed. it included data from 20,568 patients. 24 studies from China which included 2,067 patients and documented specific procedures from their region: bared external anal sphincter (BEAS), closed trans-intersphincteric fistulotomy (CTiF), internal orifice alloy closure (IOAC), proximal anal sinus resection (PASR) and cutting of the intersphincteric space (COIS). The Italian published literature used multicenter registries to document the largest number of patients exceeding 10,000. Their national FISSIT study covering both traditional and sphincter-preserving procedures such as fistulotomy, advancement flap, and LIFT, with healing rates ranging from 39% to 81.9% for complex fistula. While Indian publication included wide variety of surgical methods including TROPIS and IFTAK and PERFACT. Interestingly fistulotomy and cutting seton or its variants were reported in studies from Egypt and India and China and Spain and Italy which demonstrates its ongoing application in clinical practice. The Northern European countries of UK, Netherlands, Germany and France published data on sphincter-sparing and minimally invasive techniques but their findings were only reported in limited number of studies.

Conclusion/Discussion: The published literature about complex anal fistula surgery shows significant variable between different geographic areas. The highest number of publications about anal fistula surgery comes from China while Italy provides the most extensive patient data collection and India reported wide range of procedures. The smaller patient groups in Northern Europe focus on sphincter-saving and minimally invasive surgical approaches. It was reported that fistulotomy and cutting seton procedures is being used although new surgical options exist and incontinence remains a concern. The publication patterns reveal how geography affects choice of surgical procedures thus makes it difficult to standardize fistula surgery, as some procedures performed routinely in one region are almost rarely reported in another.

Geographic Distribution of Reported Procedures for Complex Anal Fistula (2020-2025)
Summary of published studies (2020-2025) showing procedure types, case numbers, and country-wise variation in complex anal fistula management.