I use the intestinal derotation in those cases where I have to perform an isolated resection of the third or fourth portion of the duodenum, and once, I used to resect the third portion of the duodenum in a young girl with a large traumatic perforation of the thrid portion of the duodenum. I actually wrote the case report and I intended to submit to the Trauma journal, but it is still sitting in my desk.
To undertsand the steps required to accomplish the intestinal derotation, it is first necessary to review the embriology of intestinal rotation and normal fixation. At about the 8th week of intrauterine life there is a protrusion of the midgut into the base of the umbilical cord. Two weeks later, at about the 10th week of intrauterine life, there is withdrawal of the duodenum within the abdomen followed by rotation and eventual placement of the duodenal-jejunal junction below and to the left of the superior mesenterin vessels. Follwoing this phase, there is the completion of the intestinal rotation by withdrawal of the remaning midgut colon within the abdomen and passage of the cecum above the superior mesenteric vessels to the right. Eventual fixation of the cecum in the right lower quadrant stabilizes the intestinal mesentery along a broad base which extends upward to the ligament of Treitz. Following normal intestinal rotation, the duodenum has become a retroperitoneal structure. The right colon and cecum are attached to the right lower quadrant and to the right parietal gutter and the small bowel becomes attached to the retroperitoneum by a broad based mesentery that runs from the ligament of Treitz to the ileocecal valve.
When properly performed intestinal derotaion will lead to a reconstitution of the anatomy found at the 8th week of intrauterine life.
The following are the steps required to perform the intestinal derotation:
1. The transverse colon must be lifted caudad to expose the ligament of Treitz which must be transected with sharp dissection at this time;
2.Next, the cecum and right colon must be totally mobilized by incising the peritoneal attachments of the cecum, ascending colon, and hepatic flexure. After having taken donw the hepatic flexure, you must incise the peritoneum overlying the first and second portion of the duodenum. At this point, mobilize the head of the pancreas, bluntly. Following thi step, you should have the colon totally mobilized and to the left of the aorta and the duodenum should be fully kocherized. The aorta and IVC as well as the mesenteric vessels are visible at this time (Cattell maneuver SGO 1960).
3.The next step consists of transecting the broad based mesenteric ligament from the ileocecal valve to the transected ligament of Treitz.To accomplish this, your assistant will lift the cecum and small bowel exposing the mesentery.
4. Next, derotate the small bowel around the superior mesenteric axis. This is accomplished by derotating the small bowel in a clock-wise fashionaround the SMA.
5.After this step, the second, third, and fourth portion of the duodenum are free of the mesentric vessels, and when you pull the jejunum to the right, you can clearly see the second, third, and fourth portion of the duodenum continue directly in a straight line with the jejunum. At this point, you can resect the third and fourth portion of the duodenum without any difficulty.
6. Since the derotation leads to a new intrabdominal anatomy with the appendix in the left upper quadrant, I remove the appendix in patients less than 60 years old.
A common question asked is whether there is an increased incidence of mid gut malrotation following this procedure; to the best of my knowledge and review of the literature, I believe not. It sounds complicated without figures, but it is actually quite simple. If you wish you can try it when you perform a right hemicolectomy.