Cystic structure posterior to knee

Noticed as swelling or pain

Differential diagnosis: popliteal aneurysm, venous thrombophlebitis

2D imaging demonstrates the shunt as a corrugated tubular structure extending from the portal vein to the hepatic vein.

Color Doppler imaging demonstrates patency of the shunt.

Spectral Doppler analysis of the portal vein, hepatic artery, shunt (proximal, mid, distal), hepatic veins, IVC, and splenic vein.

PSV in the shunt: 73–185 cm/s; compare with baseline postoperative examination

Decreased portal flow with shunt failure; hepatic artery flow increases with increased RI (>0.6).

Baseline (within 24 hours of surgery) 2D evaluation of liver and biliary system, color and spectral Doppler of the hepatic artery and portal vein should be performed. Ascites and perihepatic fluid collections are common.

Complications include infection, vascular thrombosis (hepatic artery, portal vein), stenosis or anastomosis leakage, bile duct stricture or stenosis, bilomas, hematomas, renal dysfunction, and recurrence of original disease.

Rejection: fever, malaise, anorexia, hepatomegaly, elevated bilirubin, ALP, and serum transaminase.

Hepatic artery thrombosis (absent signal) may be noted along with parenchymal changes.