-Review-

The Role of the Spleen in Portal Hypertension

Hiroshi Yoshida, Tetsuya Shimizu, Masato Yoshioka, Akira Matsushita, Youichi Kawano, Junji Ueda, Mampei Kawashima, Nobuhiko Taniai and Yasuhiro Mamada

Department of GI and HBP Surgery, Nippon Medical School, Tokyo, Japan

As liver disease progresses, intrahepatic vascular resistance increases (backward flow theory of portal hypertension) and collateral veins develop. Adequate portal hypertension is required to maintain portal flow into the liver through an increase in blood flow into the portal venous system (forward flow theory of portal hypertension). The splenic artery resistance index is significantly and selectively elevated in cirrhotic patients. In portal hypertension, a local hyperdynamic state occurs around the spleen. Splenomegaly is associated with a poor prognosis in cirrhosis and is caused by spleen congestion and by enlargement and hyperactivation of splenic lymphoid tissue. Hypersplenism can lead to thrombocytopenia caused by increased sequestering and breakdown of platelets in the spleen. The close relationship between the spleen and liver is reflected in the concept of the hepatosplenic axis. The spleen is a regulatory organ that maintains portal flow into the liver and is the key organ in the forward flow theory of portal hypertension. This review summarizes the literature on the role of the spleen in portal hypertension.

J Nippon Med Sch 2023; 90: 20-25

Keywords
spleen, hemodynamics, portal hypertension

Correspondence to
Hiroshi Yoshida, Department of GI and HBP Surgery, Nippon Medical School, 1-1-5 Sendagi, Bunkyo-ku, Tokyo 113-8603, Japan
hiroshiy@nms.ac.jp

Received, October 19, 2022
Accepted, December 2, 2022