Technique of Split-Liver Transplant for Two Adult Recipients

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1 F'UJIUWA H.EAL,THCAREi, INC. PRESENTS IMAGES mljk?zr 3TUiVU?MAZ7ON Technique of Split-Liver Transplant for Two Adult Recipients Abhinuv Humur, KhuLid Khwuju> Timothy D. SieLu$'John R. Luke, und WiLLium D. Puyne plit-liver transplantation is an innovative surgical S technique developed to expand the donor pool. It is not a new procedure; the first successful split-liver transplant (SLT) was performed by Pichlmayr et all in Since then, numerous SLTs have been performed. To date, the vast majority of SLTs have been performed for an adult and a pediatric recipient. This has significantly benefited pediatric patients, allowing for a significant reduction in waiting times. Currently, however, the majority of patients on the liver transplant waiting list are adults; more than 90% of deaths on the waiting list are of adults. Therefore, for this procedure to have a significant impact on waiting list patient mortality, it must be applied for two adult recipients. This commentary reviews the technical aspects of performing SLTs for two adult recipients. Donor and Recipient Selection Proper donor selection is crucial to the success of this procedure. Donors should be ideal to minimize the Figure 2. The donor surgery begins with complete mobilization of the right lobe and isolation of the right hepatic vein (arrow), which wil be the main outeow of the right graft. possibilityof primary nonfunction in the potential recipients. Young, hemodynamically stable donors with normal liver function test results are good candidates for splitting. Published criteria for choosing SLT donors for an adult and a child recipient2 are also likely appropriate when choosing SLT donors for two adult recipients. Donor size is also an important factor. Medium to large donors will generally have larger livers, and splitting such livers will result in two grafts of good size. Very small donors, marginal donors, and donors with evidence of fatty changes in the liver are not good SLT donor candidates. Figure 1. Diagram illustrating the split procedure. Transection is performed in the midplane of the liver, generating a right-lobe graft and a slightly smaller left-lobe graft. The middle hepatic vein is preserved with the left-lobe graft. The main hepatic arterial trunk, main portal vein, common bile duct, and inferior vena cava (WC) are all maintained with the left-lobe graft. From the Deparment of Surgey, Uniumiry of Minnesota, Minneapolis, MN. "Images in Liver Transplantation "is sponsored by Fujisawa Healthcare, Inc. through an unrestricted educationalgrant Addressreprint requesk to Abhinav Humar, MD, Uniuersiy of Minnesota, Department of Surgery, MMC 135, 420 Delaware St SE, Minneapolis, MN Telephone: ; Fm ; Copyright by the American Association fir the Sdy of Liver Diseases /02/ $35.00/0 doi:io. 1053/jltr Liver Transplantation, Vol8, No 8 (Augwt), 2002:pp

2 726 ImaKes in Liver Transplantation Figure 3. Any accessory hepatic veins larger than 5 mm (arrow) are preserved and later reimplanted separately into the IVC of the right lobe recipient. Doing so aids in outtlow of the graft. Recipient selection is also important in ensuring success. The living donor literature suggests that critically ill patients are not good recipients for partial transplants.3 This caution also applies to cadaver splits. Recipient size is not as important an issue when choosing a potential recipient for the right-lobe graft; the right lobe from a normal to large adult donor should be appropriate formost adult recipients.however, the left-lobe graft generated from SLTs is probably appropriate only for smaller adult recipients, those weighing less than 65 kg. Once the SLT donor surgery has been performed, the graft can be weighed; a graft weight-torecipient weight ratio can then be calculated. Ideally, this ratio should not be below 0.8%. Figure 5. An intraoperative cholangiogram defines the biliary anatomy. This cholangiogram shows how short the main right hepatic duct is. Division of this bile duct resulted in two separate orifices (right anterior sectoral and right posterior sectoral), which were individually anastomosed in the recipient. Donor Surgery When the liver is to be split for two adult recipients, it is transected in its midplane. Doing so generates a slightly larger right lobe (segments 5, 6,7, 8) and a somewhat smaller left lobe (segments 1, 2, 3, 4). This plane of transection is just to the right of the middle hepatic vein (Fig. 1). The middle hepatic vein and left hepatic vein are preserved with the left-lobe graft, as are the main trunks of the hepatic arterial and portal venous systems. The dissection of the liver vasculature and transection Figure 6. The liver parenchyma is transected in situ. The Figure 4. Hilar dissection is performed with isolation of transection line is just to the right of the middle hepatic the right portalvein (blue arrow), right hepaticartery (red vein.both grafts arewellperfused with no areas of arrow), and right hepatic duct (yellow arrow). ischemia.

3 Images in Liver Transplantation 727 R L l,,d... Figure 7. The right-lobe graft has been flushed and completely separated from the left lobe on the back table. of the parenchyma should be performed in situ to minimize the ischemic time for the two grafts. The hepatic dissection begins with complete mobilization of the right lobe and encircling of the right hepatic vein (Fig. 2). Short accessory hepatic veins draining the right lobe are preserved if they are larger than 5 mm (Fig. 3); they will later be reimplanted with the right-lobe graft. The porta hepatis is then carefully examined to evaluate the hepatic arterial anatomy. Regarding the dissection in the porta, our preference has been to leave the full length of the main vascular structures intact with the left lobe, i.e., the common hepatic artery with the celiac trunk, main portal vein, and common bile duct. The right lobe then retains just r Figure 9. The right-lobe graft is implanted into the recipient. The donor right hepatic vein is anastomosed to the enlarged orifice of the recipient right hepatic vein (arrow). the right-sided structures: the right hepatic artery, the right portal vein, and the right hepatic duct. The rightsided hilar structures are usually larger than the leftsided structures. Therefore, leaving the main vessels intact with the left lobe makes that transplantation easier. Next, blood supply to the right lobe (arterial and portal) is isolated (Fig. 4). An intraoperative cholangiogram can then be easily obtained via the cystic duct, giving valuable information regarding the biliary anatomy (Fig. 5). The right hepatic duct is divided as a final step before transection of the liver parenchyma. The transection plane should stay to the right of the middle hepatic vein so that this vein is retained with the left lobe. The transection is performed in situ using a device Figure 8. The cut surface of the right-lobe graft shows the Figure 10. If a large hepatic vein from segment 5 or 8 right hepatic vein (green arrow), right portal vein (blue drains into the donor middle hepatic vein, it can be sepaarrow), right hepatic artery (red arrow), and right hepatic rately reimplanted into the right lobe recipient using a duct (yellow arrow). saphenous vein graft (arrow).

4 728 Images in Liver Transplantation Figure 11. The right hepatic artery and right portal vein of the donor are anastomosed to the corresponding structures in the recipient. such as a Cavitron ultrasonic surgical aspirator (Cooper Companies Inc, Palo Alto, CA). In situ splitting has several advantages. First, it decreases the total cold ischemic time. Second, it allows the two grafts to be inspected before final division of the vasculature to ensure that they are both well perfused and viable (Fig. 6). Third, it minimizes bleeding from the cut surface on reperfusion. Several reports in the literature confirm the superior results with in situ (versus ex situ) splitting?. The liver and other abdominal organs are flushed with cold University of Wisconsin solution. The liver is removed. On the back table, the previously isolated vasculature to the right lobe is divided to completely separate the two grafts. Figure 13. The left-lobe graft before reimplanting the full length of the hilar structures (portal vein, hepatic artery, common bile duct) and IVC are preserved with the left-lobe graft. Recipient Surgery Right-Lobe Graft The cadaver SLT right-lobegraft (Figs. 7 and 8) is implanted in a similar manner as a right-lobe living donor graft. The diseasedliverisremoved, and the inferior vena cava (IVC) is preserved. The orifices of the middle and left hepatic veins are oversewn. Ensuring adequate outflow of the right graft is crucial. The orifice of the recipient right hepatic vein should be extended inferiorly onto the IVC; the donor right hepatic vein can then be sewn to the enlarged orifice of the recipient right hepatic vein, creating a large anastomosis (Fig. 9). Y I - Figure 14. The left-lobe graft is implanted in a similar fashion to that for a whole graft, with replacement of the Figure 12. A computed tomography scan early posttrans- recipient WC. Here the upper caval anastomosis is being plant performed. graft. right-lobe shows the

5 Images in Liver Transplantation 729 Any inferior hepatic veins more than 5 mm in diameter are also anastomosed directly to the inferior vena cava to aid in outflow. If a significantly large hepatic vein from segment 5 or 8 drains into the donor middle hepatic vein, we reimplant this vein in the recipient using a saphenous veingraft from the donor (Fig. 10). The donor right portal vein is then sewn to the recipient right or common portal vein (depending on which is the better size match). The donor right hepatic artery is sewn to the recipient right hepatic artery (Fig. 11). Biliary reconstruction is then performed with a Rouxen-Y hepaticojejunostomy over a small feeding tube, which is externalized. The graft sits well in the right upper quadrant (Fig. 12). L+-Lobe Grafi In left-lobe graft recipients, a standard hepatectomy is performed with resection of the inferior vena cava. The left-lobe graft (Fig. 13) issewn into place, and the recipient IVC is replaced (Figs. 14 through 16). Hepatic arterial and portal venous anastomoses are performed in a standard manner; biliary reconstruction is performed with a choledochocholedochostomy. Conclusions Given proper donor and recipient selection, SLTs can be successfully applied for two adult recipients. Donors should be ideal, i.e., young, large, and hemodynamically stable with normal liver function test results. Careful evaluation of the donor hepatic artery and biliary Figure 16. A computed tomography scan of the left-lobe graft 4 weeks posttransplant shows hypertrophy, such that it now occupies most of the right upper quadrant. anatomy intraoperatively isessential to help decide whether the split is technically possible. The split itself should be performed in situ, which helps to minimize graft ischemia. Recipients should not be critically ill, and careful attention should be paid to the graft size, especially for left-lobe graft recipients. Further experience will help to better define the limits of this procedure. Acknowledgments The authors thank Deann Ronning for her help in the preparation of this manuscript. 10 C Figure 15. The reperfused left graft is shown here. References 1. Pichlrnayr R, Bretschneider HJ, Kirchner E, Ringe B, Lamesch P, Gubernatis G, et al. Transplantation einer spenderbeber auf zwei ernpfanger (splitting-transplantation): Eine neue rnethode in der weiterentwicklung der llebersegrnent transplantation. Langenbecks Arch Chir 1988;373: Busutill RW, Goss JA. Split liver transplantation. Ann Surg 1996; 229: Marcos A. Right lobe living donor liver transplantation: A review. Liver Transpl2000;6: Reyes J, Gerber D, Mazariegos GV, Casavilla A, Sindhi R, Bueno J, et al. Split-liver transplantation: A comparison of ex vivo and in situ techniques. J Pediatr Surg 2000;35: ; discussion Goss JA, Yersiz H, Shackleton CR, Seu P, Smith CV, Markowia JS, et al. In situ splitting of the cadaveric liver for transplantation. Transplantation 1997;64:871.