CHAPTER 44 SURGICAL ANATOMY OF THE ABDOMEN AND RETROPERITONEUM
The abdominal cavity and the retroperitoneum lie immediately adjacent to one another. Some organs such as the small bowel and the colon have portions within the abdominal cavity while other parts are within the retroperitoneum. Vascular structures such as the superior mesenteric artery and vein course through both body compartments as well. A thorough knowledge of the anatomy of both the abdomen and retroperitoneum is critical for a rational operative approach to torso injuries.
EXPLORING THE ABDOMEN
It is imperative to fully mobilize the spleen in order to be able to fully inspect all surfaces. This allows for intelligent decision making as to whether splenectomy or splenorrhaphy will be wise (Figure 1). All of the ligamentous attachments must be divided in order to get the spleen up to the anterior abdominal wall.
A similar strategy is important when inspecting the injured liver. The falciform ligament should be taken down all the way to the level of the vena cava. Both triangular ligaments must be completely incised. This leaves the liver suspended only on the hepatic veins and the portal structures. This allows the surgeon to rotate the liver up out of the deep recesses of the right upper quadrant, which is especially important when evaluating injuries to the posterior right lobe. In addition, one should evaluate whether sternotomy and/or right thoracotomy with takedown of the diaphragm will be needed for added exposure.
In more severe cases of liver injury, one may also consider the Heaney maneuver, which involves complete vascular isolation of the liver. In this technique, vascular clamps are placed on the cava, above and below the liver. When combined with the Pringle maneuver and/or supraceliac aorta clamping, this should provide for a relatively dry field in order to attempt to definitively repair the liver, and the hepatic venous injury. While this can be effective, it may be difficult to dissect out the suprahepatic vena cava in order to place a clamp, unless the diaphragm has been divided or the pericardium opened via a thoracotomy or sternotomy. The infrahepatic cava must be occluded distal to the junction of the renal vein. If the clamp is placed too low, flow from the renal vein into the cava will perpetuate bleeding and continue to make exposure extremely difficult. Occasionally, complete vascular isolation can be combined with a venous bypass circuit to allow for venous return to the heart (Figure 2).
Figure 2 Hepatic venous exclusion and venovenous bypass.
(Courtesy of ATOM, L. Jacobs, MD, Cine-Med, 2004.)
An intermediate solution to injuries with a hepatic vein component is manual compression medial to the injury. This should control all inflow to the injured segment. The injured liver can then be debrided. The hepatic vein can then be identified and ligated when pressure is relaxed. The more central hepatic arterial and portal venous branches can be ligated as well using the same temporary relaxation of hand held pressure (Figure 3).
The anterior portions of the duodenum and the head of the pancreas are in the abdomen. The posterior portion of the duodenum and the head of the pancreas are in the retroperitoneum. A full Kocher maneuver (incising the lateral peritoneal reflection and completely mobilizing the duodenum and pancreas) is necessary to evaluate both structures for injuries. The body of the pancreas lies within the lesser sac. It is necessary to widely open the lesser sac to examine the posterior stomach, as well as the anterior aspect of the body of the pancreas. This is best accomplished by dividing the gastrocolic omentum.
