Comparing healing outcomes for cutting seton and the ligation of intersphincteric tract (LIFT) procedure in adult patients with complex primary fistula-in-ano

Cutting seton versus LIFT Comparison of two well-recognised surgical techniques for the management of fistula-in-ano. There is currently no procedure considered 'standard of care' in complex fistula management, but LIFT tends to be the preferred technique in many centres due to the very low reported risk of faecal incontinence. Patients will be randomised into either intervention and be analysed on a per-protocol bases. The procedures will be performed by Colorectal Surgeons with a minimum of 3 years subspecialty experience. Failure to achieve healing will be addressed surgically (as per standard of care) but cross-over between groups will not be allowed. If the fistula is converted to a simpler anatomy post failure to heal, the surgical technique required to achieve healing will be documented. Education will be provided to treating surgeons to attempt to standardise the technique across sites. Intervention: Cutting setons involve slowly tightening a silastic tie or suture around the involved sphincter. Tightening will occur at 6 weekly intervals until healing is achieved. On average, cutting setons achieve complete healing with 2-3 tightenings with a median healing time of 15 weeks. Over time, fibrosis occurs and the seton becomes more superficial. This is ideal for high fistulas that involve too much muscle to consider fistulotomy (cutting the muscle). This procedure (both the initial exploration and subsequent tightenings) can be performed under general anaesthesia or sedation at the discretion of the treating team. The use of pre-operative enemas will also be at the discretion of the treating team and is not specifically recommended. An educational, descriptive video will be made available describing the appropriate technique, and operative notes will be reviewed to ensure procedural standardisation is maintained.