Anterior gastroenterostomy is performed like the posterior, except that in this case the anastomosis of the jejunum with the stomach is made at the lower border of the anterior surface, and instead of the attachment being made close to the commencement of the jejunum it has to be effected at least 12 to 15 in. from the flexure, since the jejunal loop has to pass over the transverse colon in order to reach the point of attachment to the stomach.

Otherwise, in the use of the clamps in the methods of attachment, whether by suture, by decalcified bone bobbin, by metal button, or by elastic ligature, it differs in no respect from the posterior operation.

Fig. 16.-Anterior gastrojejunostomy showing the correct position (a) and the incorrect position (b) for the anastomosis.

The disadvantage, as we shall see later, is in the long loop of jejunum, which is apt to give rise to several complications. Personally, I always perform the posterior operation, except-

(1) When the meso-colon is very short, giving no room through which to make the anastomosis;

(2) When extensive and firm adhesions of the posterior wall of the stomach prevent a portion being drawn through a slit in the meso-colon ; and

(3) When cancer invades the posterior wall so extensively as to leave no part of it safely available for operating on.