'Latent' portal hypertension in benign biliary obstruction.

A prospective study was undertaken to evaluate the changes in portal venous pressure in patients with benign biliary obstruction (BBO) but without overt clinical, endoscopic or radiological evidence of portal hypertension. Portal venous pressure was measured at laparotomy in 20 patients (10 each with either benign biliary stricture or choledocholithiasis) before and after biliary decompression. Pressure was found to be on the high side in seven patients (> 25 cm of saline in three patients and > 30 cm of saline in four). The mean fall of pressure was 3.4 cm of saline after biliary decompression. No correlation could, however, be found between portal venous pressure and duration of biliary obstruction, serum bilirubin or bile duct pressure. Liver histology showed mild to moderate cholestatic changes but maintained portal architecture in all. Benign biliary obstruction may therefore, lead to elevation of portal pressure, even though the patient may not necessarily have any clinical, endoscopic or radiological manifestations of portal hypertension. The pathogenesis of this 'latent' portal hypertension is probably multifactorial. If biliary obstruction is left untreated the development of overt portal hypertension may become a possibility in the future.