We read with interest the article by El Gharbawy et al., who described the possibility of recovering an isolated segment [segment 4 (S4)] from the liver on the basis of the anatomies of 18 normal, fresh livers from adult cadavers. The authors also proposed possible techniques for using a deceased whole liver as 3 liver grafts for 3 patients to overcome the organ donation shortage: a right lobe, an S4 monosegment, and a lateral segment for an adult, an infant, and a small child, respectively.
Actually, we regret that this marvelous article did not cite our article, “Three Liver Grafts From a Deceased Whole Liver,” which was previously published online in early 2012. In our article, we proposed the hypothesis of triple grafts from a deceased whole liver, and we suggested a right lobe without a middle hepatic vein, an S4 monosegment, and a lateral segment for an adult and 2 small children or babies, respectively. Furthermore, because it is possible that a partial blockage of the venous outflow of the S4 graft could cause partial necrosis of S4, we also suggested that this small S4 would be better used as a graft in auxiliary partial orthotopic liver transplantation (eg, a bridge for fulminant liver failure or metabolic support for certain metabolic liver diseases). We also pointed out an important perspective of clinical practice with respect to the isolation of S4 from a whole liver and the engraftment of this graft into a recipient: the extrahepatic length of the hepatic artery for S4 [the so-called middle hepatic artery (MHA)] should be more than 1 cm. Therefore, we analyzed angiographic pictures of 143 living liver donors and recognized 3 types of arterial anatomies as possible candidates for triple grafts: (I) an accessory left gastric artery feeding the lateral segment, (II) an isolated MHA, and (III) an early bifurcation of the left hepatic artery and the MHA (ie, the distance from the bifurcation of the right and left hepatic arteries to the MHA is <0.5 cm). Overall, the possible candidates for S4 grafts included 39 donors (27.27%): 23 donors for type I, 14 donors for type II, and 2 donors for type III.
For the dissection and reconstruction of the portal vein, hepatic vein, and bile ducts of S4, the proposal in our article is similar to the proposal of El Gharbawy et al., and we appreciate their delicate work. We hope that our previous article can be read by the numerous readers of Liver Transplantation and, in turn, make the hypothesis come true and help more pediatric patients awaiting liver transplantation.
Cheng-Yen Chen, M.D.
Chinsu Liu, M.D.
Division of Pediatric Surgery
Department of Surgery
Taipei Veterans General Hospital National Yang-Ming University