Preservation of the entire anal canal in conservative proctocolectomy for ulcerative colitis: A pilot study comparing end‐to‐end ileo‐anal anastomosis without mucosal resection with mucosal proctectomy and endo‐anal anastomosis

Mucosal proctectomy with endo‐anal pull‐through anastomosis (MP + PTA) for ulcerative colitis reduces resting anal pressure and low RAP has been found to correlate with minor leakage of faeces or mucus. Our hypothesis was that conservative proctocolectomy with an end‐to‐end ileo‐anal anastomosis (EEA) would result in higher anal pressure and less leakage. Twelve patients were studied after EEA and 24 after MP + PTA: each was in good health several months after operation. After EEA, maximal RAP decreased from a median 90 cmH₂O (60‐116 cmH₂O) to 70 cmH₂O (25–104 cmH₂O, P<0·01), whereas after MP + PTA maximal RAP decreased from 85 cmH₂O (70–125 cmH₂O) to 40 cmH₂O (2–80 cmH₂O, P<0·003). RAP after EEA was significantly greater than RAP after MP + PTA (P<0·001). The pressure profile of the anal sphincter in the EEA group did not differ significantly from that of the pre‐operative group at any point from 6 to 1 cm from the anal verge, and the sphincteric high pressure zone averaged 4 cm in length both before and after operation. After MP + PTA, resting anal pressure at stations 1 to 4 cm from the anal verge was significantly less than pre‐operative pressure (P<0·001) and the sphincteric high pressure zone was only 3 cm in length compared with 4 cm before operation. Anal squeeze pressures were similar in the two groups of patients. After EEA 11 of 12 patients achieved perfect continence, day and night, whereas after MP + PTA 58 per cent of patients experienced minor faecal leakage (P<0·01). These findings suggest that the entire anal canal should be kept intact in the course of conservative proctocolectomy for ulcerative colitis.