Venographic appearance of portosystemic collateral pathways

Omphalic Bleed

Portosystemic collateralization is usually seen in patients with portal hypertension. Bleeding from the ectopic varices is reportedly rare. We present a case of a 55-year-old gentleman who presented with complaints of bleeding from the umbilicus. On examination, he was tachycardic, hypotensive, and in hypovolemic shock. Bleeding was suspected to be from the umbilical varices. Contrast-enhanced computed tomography of the abdomen with abdominal angiography revealed a cirrhotic liver with partial thrombosis of the portal vein with collaterals in the perigastric, lower esophageal, peripancreatic, splenic and mesenteric, umbilical and paraumbilical collaterals with recanalization of the umbilical vein. The bleeder was identified to be the collateral at the umbilical region from the superior mesenteric vein. The patient was treated with a Doppler-guided injection of a sclerosant into the collateral, thereby achieving successful hemostasis.

Unusual causes of varicose veins in the lower extremities: CT venographic and Doppler US findings

There are various causes of varicose veins in the lower extremities. Among the causes are venous insufficiency of the saphenofemoral junction, saphenopopliteal junction, or usual perforating veins. Traditionally, Doppler ultrasonography (US) has been used for evaluation of varicose veins. Sometimes, varicose veins arise from an unexpected anatomic source; in these cases, computed tomographic (CT) venography can provide an overview of the varicose veins. Doppler US with complementary CT venography is useful for determining the precise cause of varicose veins. Between November 2003 and March 2008, the authors evaluated 1350 cases of varicose veins in the lower extremities with both CT venography and Doppler US. The varicose veins were classified according to their causes; unusual causes were studied and included vulvoperineal varicosity, intraosseous perforating vein incompetence, round ligament varicosity, persistent sciatic vein incompetence, Klippel-Trenaunay syndrome, and portosystemic collateral pathways. Radiologists should be familiar with the complete range of primary causes of varicose veins in the lower extremities and with their radiologic manifestations and should recognize the complementary role of CT venography in their evaluation.

Model of complete separation of the hepatic veins from the systemic venous system

BACKGROUND

In patients undergoing a Fontan operation, partial diversion of the hepatic veins to the pulmonary venous atrium has been tried with various techniques. They failed because of the development of intrahepatic collaterals leading to an unacceptable right-to-left shunting. We postulate that to avoid the formation of intrahepatic collaterals, the totality of the liver has to be drained into the same pressure compartment. We have designed a model of cavopulmonary anastomosis in which a prosthetic conduit reproduces an azygos continuation, associated with the diversion of the totality of the hepatic venous return. This article reports on the early hemodynamics and the fate of the separation of the two venous compartments in long-term survivors.

METHODS

Eighteen goats were operated on; the pulmonary artery and hepatic vein pressures were recorded. During month 2, an opacification of the inferior vena cava and the cavopulmonary connection was performed. Between months 6 and 14, another opacification was performed, together with pressure recording at both ends of the conduit.

RESULTS

Postoperatively the pulmonary artery pressure was pulsatile with a mean of 10 mm Hg and the hepatic vein pressure was 0 mm Hg. The first angiogram showed patent tubes with fast progression of the contrast. Throughout the inferior vena cava injection, there was no opacification of the portal or hepatic veins. The late study showed a narrowed conduit in all animals. During the injection, a collateral was injected, feeding into the inferior mesenteric vein. No collateral circulation could be seen draining directly into the liver. The median gradient between the two ends of the conduit was 11 mm Hg.

CONCLUSIONS

The isolation of the entire hepatic venous drainage is feasible and efficient for the separation of two pressure compartments. No intrahepatic collaterals are observed with this model at short- or long-term follow-up. The separation of the hepatic venous drainage should persist without collateral circulation as long as the inferior vena cava pressure stays at the levels observed in Fontan circulation.

Trans-anastomotic porto-portal varices in patients with gastrointestinal haemorrhage

AIM

Porto-portal varices are commonly seen in patients with segmental extra-hepatic portal hypertension and develop to provide a collateral circulation around an area of portal venous obstruction. It is not well recognized that such communications may also develop across surgical anastomoses and be the source of gastrointestinal haemorrhage. The possible mode of development of such communications has not been previously discussed.

MATERIALS AND METHODS

Over a 3-year period between 1995 and 1998, porto-portal varices were demonstrated across surgical anastomoses in four patients who were referred for the investigation of acute (two), acute-on-chronic (one) and chronic gastrointestinal bleeding (one). Their medical notes and the findings at angiography were reviewed.

RESULTS

Three patients had segmental portal hypertension due to extra-hepatic portal vein (one) or superior mesenteric vein (two) stenosis/occlusion. One patient had mild portal hypertension due to hepatic fibrosis secondary to congenital biliary atresia. At angiography all patients were shown to have varices crossing previous surgical anastomoses. These varices were presumed to be the cause of bleeding in three of the four patients; the site of bleeding in the fourth individual was not determined.

CONCLUSIONS

Trans-anastomotic porto-portal varices are rare. They develop in the presence of extra-hepatic portal hypertension and presumably arise within peri-anastomotic inflammatory tissue. Such varices may be difficult to manage and their prognosis is poor when bleeding occurs.