Dynamic graciloplasty in patients born with an anorectal malformation

The aim of this study was to compare long-term results for patients born with an anorectal malformation and fecal incontinence treated with a dynamic graciloplasty with those for the total group of patients undergoing dynamic graciloplasty.

Consecutive patients with fecal incontinence after surgical treatment of anorectal malformation and treated with dynamic graciloplasty were included in this study. Preoperative assessment was performed. Postoperative follow-up consisted of anorectal manometry and registration of defecation frequency, continence scores, and postponement time of defecation.

Twenty-eight patients with a median age of 25.5 years were included in the study. The median follow-up was 4 years. A high anorectal malformation was present in 89.3 percent of patients. Conventional graciloplasty had been previously performed in 36 percent. All patients were incontinent for stools. Median frequency of defecation was four times/day. Median postponement time of defecation was 0 minutes. Rectoanal inhibition reflex was present in 17 percent of patients. Median preoperative sensory threshold during balloon distention was 30 ml and median maximum urge threshold was 165 ml. Satisfactory continence was reached in 35 percent of patients, however, 7.1 percent of patients gained this continence score by additional bowel irrigation. Twenty-nine percent of patients were incontinent for loose stool, 36 percent were incontinent for formed stool. Satisfactory continence was achieved in only 18 percent of patients with a high anorectal malformation, compared with 100 percent in patients with a low anorectal malformation. In the total group of patients with dynamic graciloplasty, satisfactory continence was obtained in 76 percent. The sensitivity threshold in patients with a successful dynamic graciloplasty was lower than that in patients with a failing dynamic graciloplasty (45 vs. 24 ml, P = 0,06). When we compare median preoperative rectal sensitivity threshold in our study group with that in the total patient group with dynamic graciloplasty, statistical difference was established (P = 0.008). Postponement time (0 to 20 minutes) and anal squeeze pressure (81 to 120 mmHg) increased significantly after surgery. Patients with an anorectal malformation had significantly lower resting and stimulation pressure than that of the total group of patients, but the difference between resting and stimulation pressure in both groups was not significantly different (P = 0.33). The difference between resting and stimulation pressure was not significantly different between anorectal malformation patients with a failing dynamic graciloplasty and patients with a successful dynamic graciloplasty. Complications were noted in 57 percent of patients. Explantation of the dynamic graciloplasty was necessary in 32 percent of patients, mainly because of infection of the implant.

Results of dynamic graciloplasty for fecal incontinence are reasonable for this specific group of patients with limited treatment options. Despite functional dynamic graciloplasty, the results are worse than those for the total group of patients with dynamic graciloplasty. Rectal sensitivity and type of malformation are prognostic factors for outcome and can be used to select patients for treatment with dynamic graciloplasty, thereby improving treatment outcome.