Hepatopedal Flow: Definition and Clinical Significance
Hepatopedal flow refers to normal blood flow direction in the portal venous system that is directed toward the liver, as opposed to hepatofugal flow which moves away from the liver. 1, 2
Normal Portal Venous Flow Direction
In healthy individuals, portal venous blood flows hepatopedal (toward the liver) in 100% of cases, carrying nutrient-rich blood from the splanchnic circulation through the portal vein into the hepatic sinusoids. 1
The term "hepatopedal" literally means "toward the liver" (from Latin: hepato = liver, pedal = toward), representing the physiologic direction of portal blood flow. 2
This normal hepatopedal flow can be readily demonstrated using Doppler ultrasound, where flow direction is determined by the color and spectral waveform characteristics. 3, 1
Clinical Context and Importance
When Hepatopedal Flow is Lost
Loss of hepatopedal flow (resulting in hepatofugal or reversed flow) is always pathologic and indicates significant portal hypertension or portosystemic shunting. 2, 4
In cirrhotic patients, spontaneous hepatofugal flow occurs in approximately 7-15% of cases, representing advanced portal hypertension with reversal of normal flow dynamics. 1, 4, 5
Hepatofugal flow does not relieve portal hypertension and does not prevent variceal development or bleeding—in fact, patients with hepatofugal flow have significantly higher rates of gastroesophageal varices. 4
Post-Surgical Considerations
After certain portosystemic shunt procedures, hepatopedal flow may be intentionally altered or lost. 1, 6
Distal splenorenal shunts maintain hepatopedal flow in the portal trunk in most cases (13/17 patients), demonstrating the merit of this selective shunt technique. 1
In contrast, interposition mesocaval shunts result in hepatofugal portal trunk flow in more than half of cases (9/17 patients). 1
Restoration of hepatopedal flow in patients intolerant of total portal diversion can be accomplished electively with considerable benefit, particularly for chronic encephalopathy unresponsive to medical management. 6
Assessment Methods
Doppler Ultrasound Surveillance
Hepatopedal flow in portal vein branches directed toward the shunt is a normal finding after TIPS placement, while hepatopetal flow in these branches (especially when previously hepatofugal) suggests shunt dysfunction. 3
Portal vein velocity of approximately 30 cm/s with hepatopedal direction represents normal flow parameters. 3
Clinical Pitfalls
Approximately half of patients with hepatofugal flow may have false splenoportographic diagnosis of portal vein thrombosis, highlighting the importance of recognizing flow direction. 4
Radiologists must be aware of technical pitfalls that can impede correct determination of flow direction in the portal venous system during imaging studies. 2
Prognostic Implications
Patients who lose hepatopedal flow and develop hepatofugal circulation have significantly lower net portal pressures (9.2 ± 2.6 vs. 15.6 ± 4.1 mm Hg) but worse clinical outcomes, including recurrent encephalopathy and sodium retention in 67% of cases. 5
The amount and efficiency of arterioportal collateral flow largely determines clinical outcomes in patients with reversed portal flow. 5
Attempts to restore hepatopedal flow in patients with fulminant liver failure are unlikely to succeed, with high mortality from intraabdominal hemorrhage despite maximum support. 6