[Colo-anal anastomosis: improvement of early function outcome by reconstruction with the colonic pouch]

Early functional outcome after ultra-low anterior resection with coloanal anastomosis (CAA) may be improved by construction of a colonic pouch. The aim of this prospective observational study was to compare results of colonic pouch-anal anastomosis (CPAA) with conventional CAA including the learning curve.

From February 1996 through May 1998, 45 consecutive patients underwent CAA or CPAA following radical rectal resection for cancer. The technique of resection was identical in both groups, and all patients received a diverting stoma. The colonic pouch was constructed using linear staplers. Three and 12 months following stoma closure subjective continence and bowel habits were assessed; anal manometry was performed at 3 months.

20 patients with CPAA (9 F, 11 M, age 62 +/- 9 years) were compared to 25 CAA patients (11 f, 14 m, age 64 +/- 10 years). There was no mortality, and morbidity was comparable between groups. Three months following stoma closure, in the CPAA group bowel frequency was significantly diminished (1.4 vs 5.8; P < 0.0001), fewer patients had liquid motions (0/20 vs 12/25 patients; P < 0.0001), and more were continent (20/20 vs 4/25; P < 0.001) and able to defer defaecation (20/20 vs 2/25; P < 0.0001). Functional anal canal length was significantly shorter in CPAA patients (2.9 vs 3.5 cm; P < 0.008). Although at 12 months follow-up continence had improved in patients with CAA, bowel frequency (2.5 vs 1.3; P < 0.002), and number of patients with liquid motions (10/25 vs 0/20; P < 0.007) and passive incontinence (12/25 vs 0/20; P < 0.0001) were still significantly higher than the CPAA group.

Even including the learning curve, CPAA may yield superior functional results at 3 months and 1 year compared to conventional CAA without increasing morbidity.