Adaptation of split liver grafts in pediatric patients

The first case of reduced liver grafting in a child was performed as an in situ procedure in 1972, by Starzl and Demetris (1). However, the unsuccessful outcome of this and other sporadic attempts revealed the difficulties and controversies of donor surgical technique, recipient selection, implantation, and what to do with the ‘leftover’ liver segment. These technical issues of graft reduction were further developed and reported by Bismuth and Houssin (2) in 1983 and by Broelsch et al. (3) in 1984, and had a significant impact on patient and graft survival. More importantly, however, a decrease in pretransplant mortality was evident. Broelsch simultaneously applied this technology to the living-related donor, and subsequently in 1989 Pichlemyer et al. (4) addressed the issue of the ‘leftover segment’ and described the technique of splitting a liver graft ex situ and transplanting two recipients. Although the initial results with such procedures were inferior to wholeorgan grafting, developments with the more technically demanding arterial and biliary anastomosis and improvements in graft preservation produced enhancements in the utilization of reduced-size grafts, through livingrelated donors, reduced cadaveric liver grafting, or ex situ splitting of a cadaveric liver graft (5). The establishment of comparative survival with these variations of reduced liver grafting to whole-organ cadaveric survival ushered the next step in enhancing graft and patient survival: split liver transplantation applying the in situ split technique introduced by Rogeirs et al. (6) in 1985. With this technique, the liver can be split in situ (similar to a living-related donor procedure) in the hemodynamically stable cadaveric donor. In a brief US registry encompassing 1988–96, accumulated by Emre (7) and reported at the American Society of Transplant Surgeons meeting in 1988, 104 cadaveric liver grafts were split and transplanted into 208 recipients; 62 organs were utilized locally, and 41 organs were shared between centers. During this period the number of centers performing split liver transplants increased from two to 18. In this review, the patient and graft survival rates were 87% and 72%, respectively, with a re-transplantation rate of 15%. Complications included primary nonfunction (5.2%), hepatic artery thrombosis (7.2%), and biliary complications (1.9%). A similar European experience between 1988 and 1993 reported 50 donors producing 98 grafts that were transplanted with a mortality of 27%, graft loss of 36%, and a re-transplantation rate of 18%. Patient and graft loss were as a result of primary non-function (4%), hepatic artery thrombosis (7%), and biliary complications (20%). The pediatric results with segmental transplantation reported by the United Network for Organ Sharing (UNOS) registry in an accumulated experience between 1991 and 1996 shows that during the time-period of 1991–96, 2,636 whole liver grafts were performed as compared to 246 living-related donations, 89 split graftings, and 438 reduced liver grafts that were implanted in children. The survival rates after these various types of transplants were comparable with the whole organ and living-donor organ groups, but less satisfactory after split liver and reduced transplants. However, if the very urgent (status 1) cases are excluded, the patient and graft survival rates were similar for all types of grafts. Therefore, it is important to realize that comparative survival results with different hepatic segmental transplants must take into account the medical severity of the patients receiving these grafts (Table 1). However, these results have progressed gradually, as evidenced by survival reports of patients receiving split liver transplantation over the last 10 yr; the survival rates range from 50% in Pediatr Transplantation 2001: 5: 148–152