Angiographic evaluation of portal hypertension

Abstract

Recent advances in CT (computed tomography) scanning have made it possible to obtain clear 3D depictions of the vascular system. But angiography of the portal vein system is essential in order to grasp the hemodynamics of portal hypertension or to perform interventional radiology of varices. Angiography systems are now being equipped with C-arm cone-beam CT or gantry-type CT scanners. Portography is obtained during portal phase of superior mesenteric arteriography using a vasodilator or by angiography via a catheter inserted directly into the portal vein. CT during arterial portography is the gold standard to diagnosis of hepatic tumors. Percutaneous transhepatic portography is applied to perform interventional radiology such as percutaneous transhepatic portal embolization, percutaneous transhepatic obliteration of esophageal varices, or embolization of portosystemic shunts. In the case of portal vein obstruction, transileocolic vein portography is performed under laparotomy. Balloon-occluded retrograde transvenous venography is conducted to ascertain the development of the collateral veins before balloon-occluded retrograde transvenous obliteration. Hepatic venography is conducted under balloon occlusion of the hepatic vein, and wedged hepatic venography is utilized to investigate the portal pressure indirectly. Moreover, vascular anatomy of portal hypertension and pathological conditions such as esophageal varices, gastric varices, ectopic varices, or hepatic encephalopathy are described from the standpoint of hemodynamics.