[Doppler-duplex ultrasonography in the diagnosis of cavernous portal vein].

UNLABELLED

Prehepatic portal hypertension caused by cavernous transformation of the portal vein has been more and more considered as a multiorgan disease with circulatory changes in numerous organs related to systemic and splanchnic vascular network [1]. Honeycomb-like, spongy, cavernous portal vein is a rare clinical and pathoanatomical entity which usually results from portal vein thrombosis. Recanalization and neovascularization processes lead to cavernomatous transformation of the portal vein lumen and formation of periportal collateral hepatopetal venous varices (Petren's veins) [5, 6]. Recently, with Doppler ultrasonography and angiography cavernous portal vein has been identified as the cause of prehepatic portal hypertension. Usage of color Doppler and duplex Doppler ultrasonography has greatly contributed to diagnostic efficiency, while therapeutically, the disease remains a serious and controversial problem.

METHODS

At the Institute of Digestive Diseases, Clinical Centre of Serbia, 8 patients with cavernous portal vein were studied in the period 1995-1997. Real-time duplex and color Doppler ultrasonography (Toshiba-SSA 100A with sector duplex probe 3.75 MHz, and 9 ATL with color Doppler convex duplex probe 3.5 MHz) were used. Indirect (arterial) portography was used for imaging of lienoportal system in the venous phase of angiography as follows: catheterization (Seldinger's technique) of the coeliac trunk or lienal artery, and catheterization of the superior mesenteric artery. Indirect portography was performed by injection of 60-80 ml of the contrast medium by an automatic pump, at 10-14 ml/sec, i.e. 8-10 ml/sec by the digital technique [7]. Peroral fiberendoscopy was performed in all patients by Olympus GIF-XQ 10 endoscope.

RESULTS

In our study the conventional ultrasonographic examination failed to provide an appropriate image of the normal portal vein. In hepatoduodenal ligament multiple tubular and round structures were seen, revealing an atypical honeycomb or spongycavernous shape of the venous lumen (Figs. 1 and 2). Doppler ultrasonography of the lumen of these venous collateral structures revealed a continuous, hypokinetic flow, mid-rate 7.4 cm/sec, which was always hepatopetally directed (to the liver). Color Doppler ultrasonography detected extensive portosystemic collateralls in all patients, and varices in the gallbladder wall in 1 patient. The results of indirect portography correlated well with Doppler ultrasonographic findings. In all patients hepatopetal flow was found (Figs. 3 and 4). The aetiology was diverse: idiopathic, liver cirrhosis, haematological diseases, Crohn's disease and Marfan's syndrome. Two patients had IV degree varices in the distal third of the oesophagus, and 4 patients had II/III degree varices. Patients with posthepatic liver cirrhosis and Crohn's disease had no varices in the distal third of the oesophagus and gastric fornix.

DISCUSSION

Since Pick (1909) described this malformation as the hepatopetal collateral, the haemodynamic concept of this entity has not been changed. Doppler ultrasonography and angiography confirm that the blood flow in cavernomas is hepatopetal, i.e. compensated and functional. Cavernous transformation of the portal vein is clinically manifested by bleeding from oesophagogastric varices. Haemathemesis is the most alarming complication and may be the first clinical sign. The haemorrhage is usually recurrent and profuse, but in most cases it is tolerated well owing to preserved hepatic function in patients without liver cirrhosis [19]. Portosystemic collateral circulation may take place via retroperitoneal and other spontaneous venous shunts, not involving the left gastric vein or vv. gastricae breves, when oesophagogastric varices are absent (our patient with Crohn's disease and posthepatitic B cirrhosis). Splenomegaly with hypersplenism is always present with cavernous transformation of the portal vein, and usually precedes the occurrence of gastrointestinal hae