BACKGROUND: Congenital portosystemic shunts (PSS) with preserved intrahepatic portal flow (type II) present with a range of clinical signs. The indications for and benefits of repair of PSS remain incompletely understood. A more comprehensive classification may also benefit comparative analyses from different institutions. METHODS: All children treated at our institution for type II congenital PSS from 1999 through 2009 were reviewed for presentation, treatment, and outcome. RESULTS: Ten children (7 boys) with type II PSS were identified at a median age of 5.5 years. Hyperammonemia with varying degrees of neurocognitive dysfunction occurred in 80%. The shunt arose from a branch of the portal vein (type IIa; n = 2), from the main portal vein (type IIb; n = 7), or from a splenic or mesenteric vein (type IIc; n = 1). Management included operative ligation (n = 6), endovascular occlusion (n = 3), or a combined approach (n = 1). Shunt occlusion was successful in all cases. Serum ammonia decreased from 130 +/- 115 mumol/L preoperatively to 31 +/- 15 mumol/L postoperatively (P = .03). Additional benefits included resolution of neurocognitive dysfunction (n = 3), liver nodules (n = 1), and vaginal bleeding (n = 1). CONCLUSION: Correction of type II PSS relieves a wide array of symptoms. Surgery is indicated for patients with clinically significant shunting. A refined classification system will permit future comparison of patients with similar physiology.