Studies of prognostic and functional outcomes in surgery for rectal cancer

Abstract

The order of priorities in surgery for rectal cancer are firstly to achieve local control and cure from the disease, secondly to minimise perioperative discomfort and complications, and thirdly to obtain the best possible bowel function.

Rectal tumours can be removed with local surgery but most common are abdominal procedures with or without a permanent or temporary stoma. There is still considerable postoperative morbidity (20- 50%) and mortality (1-4%). The intestinal anastomosis in anal sphincter saving anterior resections is also particularly at risk of defective healing and pelvic sepsis. Due to the localisation of the tumour in the rectum a specific problem is local recurrent disease in the pelvis. Postoperative functional bowel disturbances are common after restorative procedures and surgical methods to reduce these symptoms have been explored.

The present thesis has studied the impact of surgical specialisation and surgical techniques for outcomes after rectal cancer surgery at all three priority levels described above. The first study reports that the formation of a special team focussing on rectal cancer surgery led to improved surgical outcome by reducing the number of permanent stomas, reducing the incidence of local recurrences and increasing cancer specific survival.

In the second study, surgical outcome was compared between two departments with a different policy regarding the use of a routine defunctioning stoma after low anterior resection for rectal cancer with colonic J-pouch.There were no significant differences in mortality, the number of reoperations, patients with pelvic sepsis or in the number of patients being left with a stoma because of pelvic sepsis. Stoma reversals resulted in longer total hospital stay due to a second hospitalisation. These operations were associated with some morbidity.

In a prospective randomized study the functional and surgical outcome was compared between colonic J-pouch and side-to-end anastomosis in lowanterior resection. Bowel function was evaluated at 6,12 and 24 months with a questionnaire and anorectal physiology was investigated with manometry of the anal sphincter and manovolumetry of the neo-rectum. Although neo-rectal volume was larger in the J-pouch compared to the side-to-end anastomosis, this seemed to have limited if any influence on postoperative function. There was a pronounced postoperative decrease in anal sphincter pressures in both groups which did not recover within two years after surgery. This decrease was correlated to incontinence symptoms.

From these studies, it was concluded that concentrating the care of rectal cancer patients to a specialised team improved surgical and oncological outcome. The routine use of a defunctioning stoma did not reduce the risk for pelvic sepsis and necessitated a second operation for stoma reversal, which prolonged total hospital stay. The colonic J-pouch and a side-to-end anastomosis in low anterior resection for rectal cancer are methods that can be used with similar expected surgical and functional results from 6 months to two years postoperatively. Postoperative incontinence disturbances are related to anastomotic level, pelvic sepsis and male gender.