Portal hypertension in chronic leukaemia

The Aryl Hydrocarbon Receptor Is Required for Developmental Closure of the Ductus Venosus in the Neonatal Mouse

A developmental role for the Ahr locus has been indicated by the observation that mice harboring a null allele display a portocaval vascular shunt throughout life. To define the ontogeny and determine the identity of this shunt, we developed a visualization approach in which three-dimensional (3D) images of the developing liver vasculature are generated from serial sections. Applying this 3D visualization approach at multiple developmental times allowed us to demonstrate that the portocaval shunt observed in Ahr-null mice is the remnant of an embryonic structure and is not acquired after birth. We observed that the shunt is found in late-stage wild-type embryos but closes during the first 48 h of postnatal life. In contrast, the same structure fails to close in Ahr-null mice and remains open throughout adulthood. The ontogeny of this shunt, along with its 3D position, allowed us to conclude that this shunt is a patent developmental structure known as the ductus venosus (DV). Upon searching for a physiological cause of the patent DV, we observed that during the first 48 h, most major hepatic veins, such as the portal and umbilical veins, normally decrease in diameter but do not change in Ahr-null mice. This observation suggests that failure of the DV to close may be the consequence of increased blood pressure or a failure in vasoconstriction in the developing liver.

Portal hypertension due to intrahepatic obstruction in non-Hodgkin's lymphoma

Portal hypertension is rare in the setting of non-Hodgkin's lymphoma. We report here the case of a 73-year-old man presenting with diffuse high-grade B-cell lymphoma affecting predominantly the liver with large space occupying lesions. Histological examination of liver specimens showed abnormal large lymphoid cells whereas adjacent non-tumoural liver was normal. Portal hypertension was documented by upper gastrointestinal endoscopy that showed grade II oesophageal varices and measurement of portal pressures via transjugular approach showing increased hepatic venous pressure gradient (24 mmHg). We assume that portal hypertension was mainly related to these space occupying lesions.

Noncirrhotic portal hypertension

This article reviews the different conditions leading to noncirrhotic intrahepatic portal hypertension, describes the related vascular lesions, and provides a review of the clinical characteristics, diagnosis, and treatment options available. Diseases associated with noncirrhotic portal hypertension are also specifically discussed.

Oesophageal varices: a potentially fatal complication of liver metastases

Haemorrhage from oesophageal varices is a common and potentially life-threatening complication of portal hypertension, which is usually due to cirrhosis of the liver. Although liver metastases and hepatic dysfunction frequently occur in malignant disease, reports of oesophageal varices arising as a consequence of metastatic liver disease are sporadic, suggesting that this complication is unusual. Indeed, one review of the literature identified only 23 cases, although a few others have subsequently been reported. The management of such patients bleeding from oesophageal varices is clearly very different from bleeding due to other causes such as peptic ulceration. We report three cases and review the literature. All of our cases presented to us within a period of one year, suggesting that this complication of metastatic liver disease is more common than originally considered to be the case.

Thioguanine used in maintenance therapy of chronic myeloid leukaemia causes non-cirrhotic portal hypertension. Results from MRC CML. II. Trial comparing busulphan with busulphan and thioguanine

Portal hypertension with varices developed in 18/675 patients with chronic myeloid leukaemia (CML) in a randomized trial comparing busulphan with busulphan and thioguanine. All 18 had received the drug combination and none busulphan alone (P less than 0.0001). Ascites was also seen significantly more often in the combination arm (P less than 0.05). These results strongly suggest that the addition of thioguanine was responsible for the development of portal hypertension. The histological features were predominantly those of non-cirrhotic portal hypertension--either idiopathic portal hypertension with minimal morphological abnormalities, nodular regenerative hyperplasia or in two cases leukaemic infiltration only was noted. Cirrhosis was present in 3/16 cases studied. Both treatment groups developed abnormal liver function tests during the chronic phase, but particularly with progression of the disease. During chronic phase abnormalities were significantly more frequent in those receiving busulphan and thioguanine-alkaline phosphatase (P less than 0.02), transaminases (P less than 0.04), bilirubin (P less than 0.05), multiple abnormalities (P less than 0.01). The development of portal hypertension was often associated with abnormalities of these tests; however, lack of specificity precludes their use as a predictor of subsequent clinical problems. Thioguanine confers no survival advantage in this disease. In view of its hepatotoxicity it should not be used routinely for maintenance of control in chronic phase CML.

Idiopathic portal hypertension associated with cytotoxic drugs

Four patients developed clinically important portal hypertension with histological features of idiopathic portal hypertension while they were receiving cytotoxic drugs for chronic myeloid leukaemia and Hodgkin's disease. Mild sclerosis of some small portal triads was the only abnormality seen at light microscopical examination in three of the four cases. In the remaining case light microscopical findings seemed to be normal. Two cases examined by electron microscopy showed perisinusoidal fibrosis; in one case this was the only abnormality detected. There is an association between idiopathic portal hypertension and the use of chemotherapeutic agents, particularly thioguanine. Adequate histological examination of liver tissue, including electron microscopic studies, is recommended for patients who develop hepatic problems while receiving cytotoxic treatment to elucidate this problem.

Noncirrhotic portal hypertension due to lymphoma. Reversal following splenectomy

We report a case of bleeding esophageal varices associated with lymphoma. Splenectomy alone reversed the patient's portal hypertension as assessed hemodynamically and clinically. Mechanisms leading to portal hypertension in the setting of splenomegaly from hematologic disorders are discussed. An approach to operative management of these patients, based on preoperative hemodynamic measurements, is suggested for future consideration.

Chronic oral arsenic intoxication as a possible aetiological factor in idiopathic portal hypertension (non-cirrhotic portal fibrosis) in India

Estimates were made of the arsenic concentration in liver specimens from nine patients having idiopathic portal hypertension (IP), and in four livers these were found to be significantly higher than those in patients with cirrhosis and in control subjects. The splenovenogram revealed extensive portosystemic collateral circulation. Corrected sinusoidal pressure and blood flow studies showed higher levels in four patients than in normal subjects. Microscopic examination of liver tissues revealed periportal fibrosis. The higher hepatic arsenic levels that were found were due to the inadvertent drinking of water contaminated with arsenic, adulterated opium, and indigenous medicines. A history of opium intake was not forthcoming but two patients had drunk water contaminated with arsenic and two others had taken bhasams (Ayurvedic medicines prepared by repeated oxidation of ores). Though the aetiology of idiopathic portal hypertension is not known, it is possible that arsenic intake may be one of the factors.

Portal hypertension in a patient with chronic myeloid leukaemia

A patient with chronic myeloid leukaemia treated with busulphan for 4-5 years, developed signs of busulphan toxicity and portal hypertension with ascites, oesophageal varices and jaundice. At post-mortem there was minimal leukaemic infiltration but there were alterations in the liver architecture sufficient to explain the portal hypertension. The pathogenesis of the liver changes and their possible relationship to splenomegaly and busulphan toxicity are considered.