Courtesy of J. Michael Henderson, M.D., F.A.C.S., The Cleveland Clinic Foundation, Cleveland, Ohio

Liver transplantation offers a unique opportunity for intraoperative blood flow measurement. Since the blood supply to the liver originates from two sources, the portal vein and the hepatic artery, a red color indicating perfusion of the liver following transplant does not guarantee that the two conduits, the portal vein and the hepatic artery are both functional. Transit-time ultrasound flowmetry assures this functionality. Other reasons include:

1. Donor/Recipient Graft Mismatch - LDLT

   Troisis et al report that in living donor liver transplant (LDLT), graft size mismatch is a major concern because hyperperfusion to the newly grafted liver may lead to graft dysfunction and poor survival. They advocate flow measurement during liver transplant surgery in order to determine if there is a donor/recipient graft mismatch and to decide whether measures should be taken to remedy the mismatch. 1Troisis, R., Hemptinne, B., Clinical Relevance of Adapting Portal Vein Flow in Living Donor Liver Transplantation in Adult Patients,” Liver Transplantation 2004 9(9) S36-41.

 

2. Check the Quality of the Hepatic Artery Anastomosis and Its Functionality

   Although the hepatic artery only supplies 20% of the blood to the liver, its blood is oxygenated and it is the sole contributor to the biliary tree in the liver. For successful transplantation, it is critical for the hepatic artery to remain functional after transplant. Although microsurgical techniques have reduced the incidence of hepatic artery thrombosis (HAT), intraoperative blood flow measurement of the hepatic artery offers a functionality test of the hepatic artery before closure.

 

3. Check for Kinking of the Portal Vein

   A technical problem that Starz^l cites in his Atlas of Transplant Anatomy1 is the importance of the a snug fitting portal vein over the liver. It is crucial to correctly size the portal vein for anastomosis to the recipient portal to prevent kinking of the portal when the liver is retracted into place in the abdominal cavity. As in CABG surgery, intraoperative blood flow measurement would detect any such kinking of the vein so that it could be immediately corrected.

Recommended Flowprobe Sizes

Liver Transplant Surgery

Protocol with accompanying flow chart for successful intraoperative blood flow measurements for quantitative assessment of hepatic artery and portal vein function during liver transplant surgery.

Key Liver Transplant Publications

A focus note that lists a few of the landmark liver transplant publications that have used intraoperative flow measurements to augment their surgical decision making.

Liver and Renal Transplant References

A reference list of transplant publications that have used intraoperative flow measurements to augment their surgical decision making.

Why Measure Flow during Liver Transplant Surgery

A focus note that addresses the benefit and value of intraoperative blood flow measurements during liver transplant surgery.

Why Do Portal Flows Fluctuate?

A focus note that addresses the frequently asked question about the fluctuation of portal flows and how does one know if the flow measurements are reliable.