1. Surgical anatomy

    The spleen is an intraperitoneal organ, located between the stomach, diaphragm, left kidney, and colon. Because of its close relationships, splenomegaly may impair the functioning of these organs. The tail of the pancreas directly faces the splenic hilum. Trying to stop splenic hemorrhage by uncontrolled clamping of the splenic hilum always puts the pancreas at risk!

    The spleen is invested by peritoneum except for the hilum and the region in juxtaposition with the tail of the pancreas. This results in duplications of the peritoneum, which are considered to be part of the lesser sac:

    • The phrenicosplenic ligament extends from the inferior aspect of the diaphragm to the splenic hilum. It comprises the tail of the pancreas (pancreaticosplenic ligament), all of the splenic vessels, and the trunk of the left gastroepiploic artery. Caudad, it attaches to the splenocolic ligament.
    • The gastrosplenic ligament inserts on the greater curvature of the stomach and the splenic hilum. It comprises the short gastric arteries and veins and the left gastroepiploic artery.
    • The splenocolic ligament attaches the left colonic flexure to the inferior pole of the spleen.

    In addition, numerous secondary adhesions with adjacent structures will arise over the years. It is here where the capsule of the spleen is liable to tear during dissection. Therefore, extreme caution should be exercised when exposing the organ. On the one hand, a torn capsule results in unnecessary blood loss with diffuse bleeding, thereby impairing exposure of the field. On the other hand, in patients with hematopoietic disorders the capsule of the spleen must remain intact to prevent seeding of the peritoneal cavity with splenic tissue (“peritoneal splenosis”).

    In patients with hematological disorders, the first step in elective surgery mandates the search for accessory spleens, which are seen in approximately 25% of cases. They may grow to considerable size after splenectomy, thereby negating the benefit of the procedure. For ontogenetic reasons, the fully functional accessory organs are always located on the left side. It is therefore always advisable in such cases to carry out the search in the following order: Splenic hilum, tail of the pancreas, gastrosplenic ligament, greater omentum, mesentery, and left lower quadrant!