Use an incision that provides good exposure to the epigastric region. Generally, an upper midline or a chevron-type incision, depending on the build of the patient, is elected. Palpate the abdomen after the patient is asleep and plan an incision that is located directly over the palpable mass, if possible.

The typical retrogastric cyst is approached through the anterior wall of the stomach. Place stay sutures of 2-0 silk in the anterior wall of the stomach in a convenient and mobile location, well away from the pylorus. Incise the gastric wall longitudinally with electrocautery. A generous longitudinal gastrotomy, at least 5 to 6 cm in length, is needed. Secure all bleeding points. Place an 18-gauge needle into the pseudocyst through the posterior wall of the stomach. Aspirate and confirm that there is no blood in the cyst. If blood is obtained on aspiration, the possibility of a cyst eroding into the splenic artery should be strongly considered. (In this case, consider closing the abdomen and obtaining angiographic embolization.) Alternatively, the cyst must be widely opened through the gastrocolic omentum and direct suture control of the splenic artery achieved. Splenectomy may be needed. Closed-suction drains must then be placed in the cyst to provide external drainage. Culture the cyst fluid.

Aspirate about 100 mL of cyst fluid and then inject 50 to 100 mL of water-soluble contrast material and obtain a radiograph. This will demonstrate the anatomy of the cyst and whether or not there are septations that must be treated. Depending on the adequacy of preoperative studies, this step may be omitted. Place stay sutures in the posterior gastric wall and prepare to make an incision into the back wall of the stomach.

The anatomic relationships of the pancreas, the location of the pancreatic pseudocyst, and the anatomic fusion of adjacent organs in response to inflammation allow internal drainage of pancreatic pseudocysts.

The head of the pancreas lies in the duodenal curve. Superiorly, it is overlapped anteriorly by the first part of the duodenum; elsewhere, its margin is indented by the duodenum. Its anterior anatomic relationships include the first part of the duodenum, the gastroduodenal artery (which makes a groove in the pancreas that delineates head from neck), the transverse mesocolon, and the jejunum. Posteriorly, the head of the pancreas lies on the right diaphragmatic crus, the inferior vena cava and terminal segments of the renal veins, and the aorta. The inferior part of the head is continuous with the uncinate process, which lies in the space between the superior mesenteric vessels and the aorta. The bile duct is either posterior to the head of the pancreas or embedded within the substance of this gland.