Ligation of intersphincteric fistula tract (LIFT) for trans-sphincteric cryptoglandular anal fistula: long-term impact on faecal continence

Abstract

Background: The ligation of intersphincteric fistula tract is a surgical technique designed to treat trans-sphincteric anal fistulas aiming to preserve sphincter integrity. Recent studies suggest its efficacy in short-term fistula healing with limited impact on continence. However, comprehensive prospective data on long-term outcomes, including recurrence and bowel continence, are limited. The present study aims to report on the long-term functional outcomes.

Methods: Patients who underwent the ligation of intersphincteric fistula tract procedure for trans-sphincteric cryptoglandular anal fistulas between July 2012 and October 2018 at two Dutch referral centres were retrospectively reviewed. The primary outcome of interest was the long-term bowel continence after the ligation of intersphincteric fistula tract procedure, using the faecal incontinence severity index. Short-term data (collected in 2018) and long-term data (collected in 2023) on bowel continence, healing rates and recurrences were obtained through electronic records and Rockwood questionnaires. Sankey diagrams were used to visually represent individual variations in continence status (preoperative versus follow-up).

Results: Among 110 patients included (50% female, median follow-up 92 months), 101 patients (92%) were treated with previous surgeries (median 2, range 0-6) and 80% had previous seton drainage. Preligation of intersphincteric fistula tract, 16% of the patients reported incontinence (mean(s.d.) faecal incontinence severity index: 2.4(7.5), increasing to 18% after ligation of intersphincteric fistula tract at short-term follow-up, including 11% newly induced cases. Long-term follow-up collected using Rockwood questionnaires (63% response rate) in 69 patients uncovered a 74% incontinency rate (mean(s.d.) faecal incontinence severity index: 9.22(9.5). In those patients without subsequent surgery 49% (17 of 35) reported incontinence at long-term follow-up. Primary fistula healing after ligation of intersphincteric fistula tract was 28%. Preoperative seton drainage significantly improved healing rates (33% versus 9%). Notably, 43% (34 of 79) of unhealed fistulas transitioned into intersphincteric tracts; in these patients, 19 were treated with subsequent fistulotomy achieving cure in 18 cases.

Conclusions: Ligation of intersphincteric fistula tract healing rates fell below recent literature standards. Although the immediate impact on postoperative continence appears minimal, long-term incontinence rates are concerning. In recognizing the deterioration of individual continence, we advocate for a patient-centered approach and urge fellow researchers and clinicians to collect comprehensive prospective continence data.

Fig. 1

Flow diagram showing outcome of patients with unhealed fistulas after LIFT procedure LIFT, ligation of intersphincteric fistula tract; PMP, Permacol paste; TAFR, transanal advancement flap repair; IFO, internal fistula opening; ‘other’ category includes: Permacol paste, laser, bio-LIFT, seton and wait & see policy.

Fig. 2

Sankey diagram of long-term questionnaire respondents in 2023 (n = 69): change in continence status per individual case irrespective of additional surgical treatment after LIFT LIFT, ligation of intersphincteric fistula tract; preop, preoperative bowel continence status; (L), long-term data from 2023 questionnaires; minor, incontinence for gas or mucus; major, incontinence for liquid or solid stool.

Fig. 3

Sankey diagram of continence status per individual case; exclusion of non-respondents in 2023, patients with additional surgical treatment after LIFT procedure and worsening of continence status (n = 45) LIFT, ligation of intersphincteric fistula tract; preop, preoperative bowel continence status; (S), short-term (data from 2018); (L), long-term data from 2023 questionnaires; minor, incontinence for gas or mucus; major, incontinence for liquid or solid stool.

Fig. 4

Sankey diagram of continence status per individual case; subgroup of respondents who underwent fistulotomy for their intersphincteric tract after LIFT (n = 11) LIFT, ligation of intersphincteric fistula tract; preop, preoperative bowel continence status, (S), short-term (data from 2018); (L), long-term data from 2023 questionnaires.

Fig. 5

Fistula healing rate following LIFT LIFT, ligation of intersphincteric fistula tract.