We studied 16 patients with hypersplenism, splenomegaly, and moderate nonbleeding portal hypertension with the purpose of discovering a hyperdynamic component associated with splenomegaly. We treated the patients' splenic hyperdynamic component and hypersplenism with a splenectomy. We measured wedge hepatic vein pressure (WHVP) before and after superior mesenteric artery occlusion by a balloon catheter, and after splenic artery (SA) occlusion by a balloon catheter. In 11 patients, following SA temporary occlusion an average WHVP reduction of 10.4 cm saline was obtained, and SA occlusion by Gianturco's coils was performed to obtain a gradual and segmentary occlusion. No colliquative phenomena were observed, and a stable decrease of WHVP with a marked improvement of peripheral cytopenia was obtained.