Living Donor Liver Transplantation

In living donor liver transplantation, another innovative technique, part of the liver from a living donor is resected and transplanted into a recipient. The technique was first used for pediatric recipients in order to overcome the shortage of small liver allografts. Because results have been excellent, with established donor safety, living donor liver transplants are now being offered to adult recipients. In pediatric recipients younger than age 5, the left lateral segment of adult liver usually provides a size-matched allograft. For teenage recipients, a left lobe should be used. For adults, right lobe grafts are necessary to ensure enough liver volume. More than 2,000 living donor operations have been performed worldwide. Although the donor operation has been associated with low morbidity and mortality, long-term follow-up is necessary to confirm the safety of this procedure for donors, especially for donors of the right lobe grafts.

Because this procedure subjects a healthy individual (the donor) to major surgery, donor safety is essential and informed consent is crucial. The American Society of Transplant Surgeons (ASTS) has published guidelines for living donor transplantation. The risks and benefits of the living donor operation must be explained to the donor, to the recipient, and to their immediate families. In addition, donors should be thoroughly evaluated by an unbiased physician. The workup should include a history and physical, chest X-ray, electrocardiogram (EKG), blood work (including liver functions and viral serologies), and magnetic resonance imaging (MRI) with calculation of liver volume.

The procedure provides many advantages to the recipient. The transplant operation can be done electively, without having to wait for a cadaveric organ, before the recipient develops serious complications of end-stage liver disease. Furthermore, since the donor is healthy and ischemia time is short, graft quality is better than with cadaveric liver allografts. The recipient and donor operations are performed simultaneously, or in an overlapping fashion, to minimize ischemia time. Technical problems in the recipient, such as hepatic artery thrombosis and biliary leaks were seen initially but have decreased dramatically with increasing experience in technique and recipient selection. For the donors, the advantage is mainly psychological.

The liver rapidly regenerates in both donors and recipients, and normal liver volume is almost completely restored. Although this process takes 6-8 weeks, most of the regeneration occurs within the first 2 weeks following the procedure.

10.4.4. Recipient Operation for Split-Liver and Living Donor Grafts

The operation to implant a right lobe split graft is similar to whole-liver OLT (see previous discussion). In the case of left or left-lateral segment split grafts, and all living donor liver grafts, the allograft does not have the vena cava, and therefore the upper caval anastomosis is done using the piggyback technique (Fig. 10.10). The portal vein anastomosis is done between the allograft portal vein and the recipient portal vein using 6-0 Prolene continuous suture. The hepatic artery anastomosis is performed between the allograft hepatic artery (either right or left) and the recipient right or left hepatic artery using 8-0 Prolene interrupted sutures. In pediatric recipients, an operating microscope is necessary for arterial anastomoses. When the entire length of the recipient portal vein and hepatic artery is

Segmental

Hepatic

Veins

Portal Vein

Accessory

Right Hepatic Vein

Segmental

Hepatic

Veins

Portal Vein

Hcpatic Artery

Donor Right Lobe -7 Anastomoses begin

Completed

Figure 10.10. Implantation of right lobe using piggyback technique dissected into the hilum, extension grafts are rarely needed. In the majority of cases, bile duct anastomosis is done by Roux-en-Y hepaticojejunostomy using interrupted 6-0 polydiaxanone (PDS) sutures.

The implantation used is the piggyback technique, as follows: For left hemi-grafts, the liver is dissected off the cava, the short hepatic veins are ligated, and the hepatic veins are identified. The right hepatic vein is clamped and divided, and oversewn with 5-0 Prolene sutures. The left and middle hepatic veins are clamped, and the diseased liver is removed. The bridge between the left and middle hepatic veins is transected to make a single orifice. Since the vena cava is not clamped, venous return to the heart is not hampered. The donor suprahepatic cava is anastomosed to the common orifice of the left and middle hepatic veins using 4-0 Prolene running sutures. For right lobe adult-to-adultliving donor liver transplantation, performing the upper caval anastomoses is quite different. After the liver is dissected off the cava and the short hepatic veins are ligated, the right hepatic vein is encircled and clamped vertically. The left and middle hepatic veins are clamped, and the liver is removed by transecting these three hepatic veins flush on the liver parenchyma. The left and middle hepatic vein orifices are oversewn with 5-0 Prolene. The donor's right hepatic vein is anastomosed to the recipient's right hepatic vein using 5-0 Prolene running suture.

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