We read the recent article by Tashiro et al. (1) with interest. It described that the in situ reconstruction of middle hepatic vein (MHV) tributaries the using recipient's MHV, obtained by transecting the hepatic parenchyma, is a feasible strategy in right lobe living donor liver transplantation (1). In contrast, we have been using an explanted portal vein (EPV), procured ex situ without hepatic transection and used for in situ one-step reconstruction (2, 3). We present our concerns regarding the procedure described by Tashiro et al. (1) for (i) the in situ transection of the cirrhotic liver, which might harbor occult hepatocellular carcinomas (HCCs), and for (ii) the reconstruction of all the MHV tributaries in situ after reperfusion. The positive points in the use of EPV include its almost universal availability, procurement in a bloodless manner, and its larger caliber with thick wall (2). It also needs to be noted that the hepatic parenchyma does not need to be divided at all to obtain an EPV (2). On the other hand, the cirrhotic parenchyma needs to be divided for obtaining the MHV as Tashiro et al. (1) reported. Although the authors state that the MHV is procured at least 2 cm away from any HCC, this is uncertain. Steingruber et al. (3) examined the diagnostic accuracy of pretransplant radiological evaluations for HCCs and reported that CT-arterioportography with angiography had a sensitivity of 84% and specificity of 81%. In our previous comparison of the number of the HCC nodules between the pretransplant radiologic and posttransplant pathological evaluation, the accuracy of the pretransplant radiologic imaging was just 81.7% (4). Therefore, the in situ blind transection of a liver with HCCs for obtaining MHV carries the significant risk of encountering and disseminating occult HCCs in a recipient's body. The in situ splitting of an HCC-containing cirrhotic liver may present serious ethical problems. We use a shunt vessel, a saphenous vein, or an internal jugular vein in case EPV is unavailable. Regarding the patency rate of the V5 and V8, Tashiro et al. (1) reported that the 1-year patency rate of the V8 was 92%, and that of the V5 was 43%. Actually, reconstruction of an accessory hepatic veins in situ after reperfusion might be troublesome with the increase the risk of bleeding (5). To facilitate easier reconstruction, we have applied single hepatic venous anastomosis after unification of multiple venous orifices on the back table under optimal conditions since 2007 (2, 6). The 1-year patency rate of MHV tributaries in the 19 cases with the technique was 90.8% (Fig. 1A). The patency rate of V5 and V8 was same (90.8%) among those 14 cases with double reconstruction (Fig. 1B).FIGURE 1.: (A) The 1-year patency rate of the middle hepatic vein tributaries was 75.9% by the one-by-one in situ reconstruction technique (Era-I, n=22) and 90.8% by the one-step technique after ex-situ unification of multiple veins (Era-II, n=19). (B) The patency rate of V5 and V8 was same (90.8%) among those 14 cases with double reconstruction.In summary, there is the potential risk of encountering HCCs in using the hepatic veins of the native liver for reconstructing MHV tributaries. We should use extrahepatic alternative vessels including hilar portal veins with the advantage of allowing reconstruction on the back table under optimal conditions. Toru Ikegami Yuji Soejima Akinobu Taketomi Tomoharu Yoshizumi Hideaki Uchiyama Shigeyuki Nagata Yoshihiko Maehara Department of Surgery and Science Graduate School of Medical Sciences Kyushu University Fukuoka, Japan