Left-sided portal hypertension is best treated by -
Portal hypertension due to isolated splenic vein thrombosis is k/a left-sided portal hypertension.
In left-sided portal hypertension the pressures in the portal and superior mesenteric veins are normal. There is gastrosplenic venous hypertension leading to the formation of gastric varices (not esophageal varices). The splenic venous blood, blocked from its normal route due to splenic vein thrombosis, flows through the short gastric vessels to the gastric fundus and then into the left gastric vein, continuing toward the liver.

Causes of isolated splenic vein thrombosis are

pancreatitis
neoplasm - trauma
Treatment → by splenectomy
Splenectomy
Portocaval shunt
Leno-renal shunt
Spleno-renal shunt