Post-operative strictures in anorectal malformation: trends over 15 years

For decades, paediatric surgeons have employed the standard posterior sagittal anorectoplasty (PSARP) approach to deal with patients with anorectal malformations (ARM). In recent years, we noted an apparent increase in the incidence of anal stricture after surgical repair of ARM following the introduction of laparoscopic pull-through and techniques aiming to preserve the internal sphincter—the internal sphincter sparing approach (ISSA). We decided to analyse our data to find out if these new trends had added to the problem of post-operative strictures.

All patients with ARM at our institution from January 2000 to December 2015 were identified. A retrospective case note review was carried out. Data collected included patient demographics, type of ARM, operative details, and post-operative outcomes.

114 patients were identified. Ten patients were excluded. Of the remaining 104 children, 48 (46%) were female. Median age was 8.3 (range 1.2–16.8) years. Types of ARM were as follows: perineal fistula (15 patients), anterior stenotic anus (12), imperforate anus without fistula (10), vestibular fistula (32), rectourethral (bulbar) fistula (11), rectourethral (prostatic) fistula (14), rectovesical fistula (7), and cloaca (3). Twenty-seven patients with a perineal fistula or anterior stenotic anus underwent perineal procedures that were variably described by the different operating surgeons. The majority (15 patients) had an anoplasty, 5 had anal transposition, 5 had limited PSARP, and 2 patients had ISSA. Two patients with a cloacal anomaly underwent open cloacal reconstruction. Of the remaining 75 patients, 45 had a PSARP approach, 6 had a laparoscopic-assisted pull-through, and 18 had ISSA. Four girls with vestibular fistula had anal transposition and two boys with imperforate anus without fistula had anoplasty. 15 (14%) children developed anal stricture. Stricture incidence differed according to operation type. PSARP was the most commonly performed procedure, with only 6% developing a stricture. In contrast, 30% of ISSA patients and 50% of children who had laparoscopic pull-through developed a stricture. Strictures also occurred in 11 and 12% of children having anal transposition and anoplasty, respectively.

The laparoscopic-assisted pull-through involves tunnelling the sphincter muscle complex. We found that often the tunnels were not wide enough, resulting in narrowing not just at the ano-cutaneous junction but also at the deeper level. 50% developed strictures. We have modified our technique by ensuring that the tunnels are generous enough to allow the rectum to be pulled through without any resistance. ISSA unfortunately resulted in 30% of our patients developing strictures. This approach, started in 2004, was, therefore, abandoned in 2013. The standard Pena’s PSARP, with or without a laparotomy, has stood the test of time. Any modification of this approach must be carefully thought through and audited meticulously. Strictures can cause significant morbidity, which may need several revisions, and the resulting redo anoplasties run the risk of sphincter damage, ironically which the newer modifications of ISSA were trying to conserve.