Portal vein thrombosis is one of the major triggers of upper gastrointestinal bleeding in children. Bleeding episodes have a remarkable effect on the quality of life of affected patients. Thus, appropriate diagnosis and treatment are needed in order to reduce morbidity and mortality.

In reference services and research protocols, endoscopic screening should be performed in all patients with portal vein thrombosis and congenital hepatic fibrosis. Among cirrhotic patients, the indication should be conditioned to clinical evidence of splenomegaly or hypoalbuminemia. For clinicians, the recommendation is to emphasize the orientations given to guardians of patients with portal vein thrombosis and congenital hepatic fibrosis as to the risk of digestive bleeding. Cirrhotic patients with hypoalbuminemia and splenomegaly should receive the same orientations.

-Context -Portal vein thrombosis refers to a total or partial obstruction of the blood flow in this vein due to a thrombus formation. It is an important cause of portal hypertension in the pediatric age group with high morbidity rates due to its main complication -the upper gastrointestinal bleeding. Objective -To describe a group of patients with portal vein thrombosis without associated hepatic disease of the Pediatric Hepatology Clinic of the Hospital das Clínicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil with emphasis on diagnosis, presentation form and clinical complications, and the treatment of portal hypertension. Methods -This is a descriptive study of a series of children and adolescents cases assisted from January 1990 to December 2010. The portal vein thrombosis diagnosis was established by ultrasound. Results -Of the 55 studied patients, 30 (54.5%) were male. In 29 patients (52.7%), none of the risk factors for portal vein thrombosis was observed. The predominant form of presentation was the upper gastrointestinal bleeding (52.7%). In 20 patients (36.4%), the initial manifestation was splenomegaly. During the whole following period of the study, 39 patients (70.9%) showed at least one episode of upper gastrointestinal bleeding. The mean age of patients in the first episode was 4.6 ± 3.4 years old. The endoscopic procedure carried out in the urgency or electively for search of esophageal varices showed its presence in 84.9% of the evaluated patients. The prophylactic endoscopic treatment was performed with endoscopic band ligation of varices in 31.3% of patients. Only one died due to refractory bleeding. Conclusions -The portal vein thrombosis is one of the most important causes of upper gastrointestinal bleeding in children. In all non febrile children with splenomegaly and/or hematemesis and without hepatomegaly and with normal hepatic function tests, it should be suspect of portal vein thrombosis. Thus, an appropriate diagnostic and treatment approach is desirable in an attempt to reduce morbidity and mortality.

On histopathological evaluation, the immunosuppressive treatment improved the fibrosis scores, with an arrest in its progression and no development into cirrhosis. Fibrosis control is mainly associated with regression of necroinflammatory activity, which is the main treatment component in autoimmune hepatitis.