Gastric reduction/duodenal switch procedure is the most physiologically sound of current commonly performed weight loss operations. It is a combined procedure that relies on both moderate restriction and controlled absorption. The restrictive component arises from a vertical gastrectomy, wherein the easily expendible greater curvature of the stomach is removed leaving a 2–3-cm wide gastric tube along the lesser curvature of the stomach. This preserves the gastric antrum, which retains the gastric resevoir capabilities to macerate protein rich food, and protects the normal emptying mechanism of the stomach. It also preserves contact between food and the most proximal portion of the duodenum, a segment which neutralizes gastric acid and produces important intestinal hormones. To reduce absorption, the most distal 250 cm of ileum is employed to conduct the foodstream and the channel common to food and biliopancreatic juices.
Like most intra-abdominal operations, exposure for gastric reduction/duodenal switch procedure can be established using a traditional extended midline incision or via minimally invasive laparoscopic techniques. Safety must always be the highest priority. A secondary consideration is the maintenance as much as possible of the same materials and calibrations regardless of type of exposure. That being said, there are advantages and disadvantages to each technique and accordingly times where one technique may be preferable. In this chapter we will discuss the hand-assisted laparoscopic approach. We will discuss the procedure step by step and describe other techniques which we have used but subsequently discarded and why.
The midline is incised 18 cm below the xyphoid and the incision extended 7-cm caudad. This distance most often coincides with the level of the umbilicus, and therefore works well to minimize cosmetic concerns. Additionally this facilitates the repair of umbilical hernias which are not infrequent.
Exploration of the abdomen is performed in the usual manner. Using a large Richardson retractor, the cecum can be grasped with a Babcock clamp and the appendix identified. If present, at this point early in the procedure the mesoappendix only is transected using the Ligasure device. To minimize the potential for contamination, the appendix itself will be transected only at the conclusion of the procedure.
The terminal ileum is now identified. By grasping the ileum in serial fashion with two large Babcock clamps under moderate tension (to achieve “maximum stretch”), the ileum is measured and marked at 100 cm from the ileocecal valve with two sutures, of which the more proximal is cut short. This identifies not only the 100-cm distance from the ileocecal valve, but also marks the direction of the bowel. This distance may be diminished or extended, by referencing it to 10% of the total bowel length1; however, we utilize the 100-cm length as described by Marceau et al.2
Measuring of the bowel is continued proximally for an additional 150 cm. It is again marked with doubled strands of suture to distinguish this area from the previously marked 100-cm ...