Surgical Techniques Illustrated Spring 1977 [antikvár]

In the early years of this century Ernest Miles first described an operative technique that seemed to satisfy criteria for extirpation not only of primary rectal cancer but also of any early local spread. In the years that followed, the Miles approach to cancer of the rectum became generally accepted and operative risks were greatly diminished. Abdominoperineal resection of the rectum with the establishment of a permanent colostomy was believed to be the appropriate operative procedure for all tumors of the rectum and was used even for the management of some low sigmoid cancers. This concept of en bloc removal of the rectum, perirectal fat, and the contained vascular and lymphatic tissue followed the concepts of what appeared to be acceptable cancer surgery. The disagreeable features of a permanent colostomy were accepted by surgeons and patients alike in order to achieve cure. About thirty years ago, surgeons began to question the rationale for removing so much distal rectum in patients with cancer of the upper and middle portions of the rectum. Careful study of tumor extension beyond the wall of the rectum showed that the cancer spreads proxi-mally within the lymphatic and vascular systems and invades distal lymphatics only after extensively involving more proximal lymph nodes. At about the same time, study of the spread of tumor within the wall of the bowel defined the extremes of intraluminal spread in a distal and proximal direction. It became apparent that removal of the rectum and its surrounding lymphovascular tissue to a level about 5 cm below the distal margin of the tumor would safely remove all of the involved tissues unless extensive and incurable tumor spread had already occurred. Understanding the mode of spread of rectal cancers led to increasing efforts to reestablish intestinal continuity following resection of the tumor together with a safe margin of bowel and surrounding support tissues. Anterior resection of the rectum permits removal of the same amount of proximal and lateral perirectal tissue as does abdominoperineal resection of the rectum. This fact, combined with an understanding of the margin of distal bowel and surrounding tissue necessary to remove any potential spread in that direction, has permitted an anastomotic procedure for many patients who would previously have required a colostomy. There are disadvantages to performing anterior resection of the rectum from the surgeon's point of view. The technique is often tedious (especially in male patients) and, because of the difficulties of exposure, is often more time consuming to complete than the abdominoperineal resection. From the patient's standpoint, disadvantages to the operative procedure are basically twofold. Cancer recurs along the suture line in some patients treated by this technique. This recurrence is usually related either to failure to remove a sufficient margin of bowel distal to the tumor or to inappropriate choice of operative procedure because of size, spread, and degree of anaplasia of the cancer itself. The second disadvantage to the patient is the risk of leakage, which has occurred from anastomoses performed low within the pelvis. This incidence seems to be greater in those patients having low anterior resection performed below the level of the middle hemorrhoidal vessels. Varying operative techniques have been used to diminish the likelihood of all three disadvantages, and these technical features are described in this issue. The test of time has shown that anterior resection of the rectum, when applied to the properly selected patient with a suitable lesion, provides the same chance for cure as does abdominoperineal resection. Indeed, the technical aptitude of surgeons now permits anastomoses to be performed from within the abdomen at very low levels. In most patients the factors that dictate the level of the anastomosis are not technical ones regarding access but are functional limitations. If the distal stump of anorectum is less than 5 cm long, continence is usually a problem. Thus, surgical judgment becomes an important factor in choosing which operation to offer the patient whose lesion is situated about 10 cm from the anal verge. Malcolm C. Veidenheimer