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Hepatic arterial anatomy for right liver procurement from living donors

2004; Lippincott Williams & Wilkins; Volume: 10; Issue: 1 Linguagem: Inglês

10.1002/lt.20028

1527-6473

Henkie P. Tan, Amadeo Marcos,

Transplantation: Methods and Outcomes

Kishi et al. are to be congratulated for their large numbers of living donor liver transplants (from January 1996 to May 2003, 72 out of 233 patients had right-lobe living donor liver transplants [RLDLT]). They reported a 6% incidence of hepatic arterial bifurcations that might provide multiple orifices in right liver grafts by preoperative angiography, but only one right liver graft (1%) determined operatively had multiple arterial orifices. They concluded that their report conflicted with our experience, because in their series, no patients underwent double hepatic artery reconstruction in right-lobe living donor liver transplants. RLDLT, right lobe living donor liver transplants; RLDH, right lobe living donor hepatectomy; CHA, common hepatic artery; RHA, right hepatic artery; LHA, left hepatic artery. Donor safety is of paramount importance, and we cannot overemphasize it. In our series, all hepatic arterial transections were performed to protect the donor hepatic arterial supply. On occasion, when there is a single right hepatic artery but with an early bifurcation, two donor right hepatic arteries were created to the right of the common bile duct resulting in two hepatic arterial anastomosis in the recipient. In addition, all right hepatic arterial donor stumps are anastomosed in our recipients in contrast to Kishi and colleagues, where only a single anastomosis was performed if a test of sufficient back flow from another tributary was confirmed. In our latest published series1 from July 2000 to May 2002, 95 adult right-lobe hepatectomies were performed for 95 recipients with 11 (11.6%) resultant dual hepatic arterial anastomoses. We have good recipient results and excellent donor results and have reported our preliminary short-term donor results.2 Kishi and colleagues are to be congratulated for their good recipient results, but they did not present any short-term or long-term donor results. Our experience with hepatic arterial anatomy in 95 adult right-lobe living donor hepatectomy (RLDH) at a single institution is described. All donors underwent arterial angiography as part of the preoperative evaluation for candidacy. Of the 114 potential donors who underwent angiography, 19 did not proceed to donation. Three donors changed their mind after completing the evaluation process, two donors were denied on the basis of their angiogram, and 14 underwent simultaneous angiogram and liver biopsy but were rejected secondary to abnormal pathology. Of the two donors excluded after angiogram, one had celiac artery stenosis, and the other had a contour irregularity in the proximal common hepatic artery (CHA), representing either stenosis or plaque. There were no aborted laparotomies. Sixty-seven potential donors (58.7%) had normal hepatic arterial anatomy. The most common anomaly was a replaced right hepatic artery (RHA, 12.3%) followed by an accessory left hepatic artery (LHA, 6.1%) and a replaced LHA (5.3%). The respective incidence in our population was consistent with that reported in the literature.3-5 Of equal representation (1.7%) was a replaced CHA, a replaced LHA from the gastroduodenal artery, a replaced RHA with an accessory LHA, separate origin of the CHA and splenic artery, and common origin of the celiac trunk and the superior mesenteric artery. The remaining nine patients had unique aberrant anatomy. Appreciating the impact aberrant hepatic arterial anatomy can have on both the donor and the recipient's operations, we propose a simple classification system pertinent to RLDLT that first impacts the donor hepatic artery dissection with a resultant number of the recipient's arterial anastomosis. While previously reported classification systems are useful for operative planning for both general hepatobiliary surgery and cadaveric transplantation,5, 6 they are not specific for RLDLT. Careful assessment of the anatomy to avoid dissection of any artery or collateral to the left lobe is of utmost importance. Second to that, maintaining perfusion while precisely delineating the artery or arteries to the right lobe is necessary. In our living donor hepatectomies, hepatic arterial inflow is not disrupted until the graft is ready to be explanted. Of additional importance is if the patient has a dual arterial system to the right lobe, preoperative knowledge is imperative to plan an arterial conduit7 or a “Y” graft.1, 8 Either situation alters the recipient's operation. Three distinct situations arise with respect to the arterial anatomy and we propose three simple classification types (Table 1). Type I (88.4%), the most common, includes a single RHA resulting in a single recipient arterial anastomosis. Aberrant hepatic arterial anatomy, if present, is well away from the RHA and subsequently does not affect dissection at the porta hepatis. Type II (4.1%) includes all variations of a dual arterial system (two RHAs, a replaced RHA and an accessory RHA, or a normal RHA plus an accessory RHA) to the right lobe resulting in two recipient arterial anastomoses. Type III (7.4%) includes a single-donor RHA with concomitant arterial variations that must be addressed during intraoperative dissection, possibly resulting in two or more recipient arterial anastomoses. An example of this is the discovery intraoperatively, and may be discriminated by a preoperative angiogram, of an arterial branch from the main LHA or replaced/accessory LHA that may supply a branch to the R lobe (Couinaud segment 5 or 8). This occurred in three patients. The other situation that resulted in two arterial anastomoses was when the position of the bile duct necessitated transection of the RHA just at the level of the natural RHA bifurcation. This situation arose in four patients. Early on, anomalous arterial anatomy of the recipient was an issue when discovered intraoperatively. Modification of surgical technique became necessary to adapt to the unexpected anatomy. Over time, it became clear that donors with aberrant anatomy who had previously been excluded could now be candidates for successful donorship. We have had success with revascularizing two arteries to the right lobe with our technical modification of the Y-type graft.8 During the past 2 years, we have implemented a modification of the Y graft, to reduce arterial complication in all of our recipients.1 By using an extension graft that is sewn at the back table, we are able to more precisely perform arterial revascularization. This extension graft also utilizes the wider diameter of the branch patch technique when the graft is implanted. With single hepatic arterial anastomosis, the reverse extension bifurcated grafts as previously described1 is being used with an increase frequency. These arterial grafts as previously described1 do not require an additional incision or more extensive dissection. In conclusion, we emphasize the necessity for preoperative determination of the precise anatomy of the donor. Donor safety remains our primary concern, and anatomic knowledge will ensure optimal dissection during the donor operation. In our opinion, the number of resultant recipient hepatic arterial anastomoses depends largely on the safety of the donor operation. The beauty and difficulty of this operation is the highly variable hepatic arterial anatomy. Each graft poses a unique challenge, requiring the surgeon to have diverse armamentarium of surgical options.