Lower third cancer rectum: situations dictating abdomino-perineal resection

ABSTRACT

Low anterior resection for lower third rectal cancer is a great objective, however the winds are sometimes stronger and in many situations the surgeon is obliged to do abdomino-perineal resection. The aim of this work was to define different situations of patients with resectable lower third rectal cancer in whom sphincter preservation procedures could not be done and abdomino-perineal resection was the only option. During the period from July 2001 till the end of December 2004, out of 45 patients with lower third rectal cancer 31 patients had a resectable disease with no distant metastasis, out of these, curative low anterior resection was done for 11 patients, the different situation of patients who underwent abdomino-perineal resection [20 patients] represented the material of this study. All patients were evaluated clinically. Laboratory workup, rigid proctosigmoidoscopy, endorectal ultrasonography, colonoscopy and or double contrast enema, plain X ray chest, abdominal U/S and or abdomino-pelvic C.T scan, and I.V.P were all used to assess these patients. In this work, 20 patients with resectable lower third rectal cancer lost their sphincters and the surgeon was obliged to perform abdomino-perineal resection. In these patient the mean tumor height from the anal verge was 3.1 cm ranging between 0.0 - 4.5 cm. Endosonographic invasion of the anal sphincter complex was the finding in 4 patients. In another 4 patients the lower edge of the tumor was seen overlying and invading the dentate line. After full rectal mobilization a distal safety margin could not be achieved in 6 patients. An infiltrated distal resection margin by frozen section was the cause of failure to preserve the sphincter in 4 patients. Tumor seedling on a recently done haemorroidectomy wound led to abdomino-perineal resection in one patient, the last patient developed a low rectal mucoid carcinoma six months after transanal excision of 3 x 4 cm villous adenoma. Abdomino-perineal resection of the rectum is not an endangered operation. It still has its major role in the management of patients with lower third rectal cancer. The height of the tumor from the anal verge is the most important deciding factor in resectable lower third rectal cancer whether to preserve the sphincter or not. The majority of patients with a tumor edge of 4 cm or less from the anal verge may lose their sphincters