Note 60 — Chapter L · THE LARGE INTESTINES AND THE RECTUM.

It becomes a question of importance just when and where we should cease to attempt operation on the colon from above or on the sigmoid from below; in other words, the exact location of the tumor should decide the measure when it can be accurately determined. Moreover, a wide margin of bowel on either side of any new-growth which is about to be resected should be excised. The question of blood supply to the margins of the wound thus made is also of importance, as the most ideal operation in appearance may be marred by gangrene due to lack of sufficient blood supply. When there is sufficient uninvolved gut below the tumor to permit of complete operation within the abdomen it is not advisable to do anything from below; but there are some cases in which anything like complete removal can only be effected by a combination of abdominal and sacral routes. A thorough extirpation should be made above the growth as well as of the involved tissue below. Those vessels which require ligation should be tied accurately at the level of their division, and no ligation of trunks or larger vessels should be attempted at any distance from the line of division. If this be carefully carried out and the divided mesentery, with its ends, and all the fat between the rectum and the sacrum be carefully dissected out, there will rarely be difficulty in making an end-to-end reunion of the divided bowel.

It is rarely necessary to include a colostomy with this procedure; in fact, when a permanent opening has become necessary there is little possibility of removing the main growth. Colostomy is a procedure for the hopeless cases; resection is rarely to be thought of as an alternative. It should be an early not a late measure, the reverse being true of colostomy, though even this should not be too late.