Does portal pressure influence direction of portal flow and encephalopathy rates after 10-mm portacaval shunts in man?

Direction of portal flow after small diameter portacaval H graft has been found to significantly correlate with postshunt portasystemic encephalopathy rates. While some patients maintaining prograde portal flow were found to have a lower incidence of portasystemic encephalopathy, it has been suggested that high portal pressures are responsible for minimizing this complication. If both statements are true, then postshunt pressures should be higher in patients with prograde flow and in encephalopathy. Portal pressure and portal flow patterns were determined by shunt cannulation and fluoroscopy in 16 patients fully recovered from operation. Patients were screened for portasystemic encephalopathy over a 6- to 24-month period (average 12 months) at which time shunt patency was documented. Portal pressures were similar in patients with and without portasystemic encephalopathy and in patients with and without prograde flow. These results do not support the concept that protal pressure is an important determinant of portasystemic encephalopathy rates or flow patterns after 10-mm portacaval H graft.