Donor Evaluation and Donor to Recipient Dimensional Matching

Since the beginning of the Bergamo pediatric liver transplantation program, we adopted a liberal policy of liver splitting. The decision of whether or not to split a graft was based mainly on recipient rather than on donor criteria. We did not exclude children who required retransplantation or who had fulminant hepatic failure.
In the North Italia Transplant area, cadaver liver donors are allocated on a rotation basis to the $. The liver of every donor assigned to our center was evaluated for elective transplantation when at least one ABO-compatible recipient with a donor to recipient body weight ratio  12 was wait listed. Gross pathologic findings at the procurement were the main criteria for organ acceptance or refusal. The donor evaluation did not require special or additional invasive or noninvasive tests. Every accepted graft was attributed to the most urgent recipient on the waiting list. Time on the waiting list was an allocation criterion for patients with the same UNOS status.
The liver was procured and transplanted as a whole when the donor to recipient body weight ratio was  2. Donor procedures were performed using the standard technique of rapid multiorgan procurement. When the donor to recipient body weight ratio was between 2 and 12, the organ was considered for split liver. Of the two grafts obtainable with the splitting procedure, the right was offered, as a rule, to another center, with the agreement of a restitution of the split at the first opportunity. The allocation of the left grafts received from other centers according to this agreement was done with the same criteria described above. Standard surgical facilities for multiorgan procurement were utilized and no special equipment was required from the donor hospital. The splitting procedure was performed by a surgical team composed of members of both centers involved in the transplant. 
We recently employed an alternative in situ splitting technique that results in left grafts substantially larger than those obtained with the standard technique. This alternative splitting technique was adopted for patients with a donor to recipient body weight ratio 2, and with a graft-to-recipient weight ratio 0.8. We estimated the left graft volume (segments I-IV) using a formula for calculating the standard liver volume in the donors from their body surface area, and assuming that the left lobe volume was 40% of the donor’s estimated liver mass.
The splitting procedure was performed ex situ only when required for hemodynamic instability of the donor or for logistical reasons. In all cases an effort was made to limit ischemia time as much as possible. When a center with a suitable recipient for the right graft could not be found, the liver was reduced on the back table, using the standard technique.
In our series, 116 liver procurements were commenced: in 4 cases the liver was not used due to steatosis. In 4 donors considered for split liver, the procedure could not be completed because the donor became hemodynamically unstable (n=1) or because of anatomical and/or dimensional reasons (n=3). In all these cases the whole liver was procured and transplanted at another center. Out of a total of 108 procurement procedures, 73 (68%) were split livers. In all but three cases the splitting procedures were performed using the in situ technique, and in 67 cases consisted in the procurement of the left lateral segments, in 4 of the left hemiliver (segments I-IV), and in 2 cases of the right segments I and IV-VIII. In 8 cases (7%) a transplant center with a suitable donor for the right graft could not be found and the liver, procured as a whole, was reduced on the back table. In 27 donors (25%) the liver was procured and transplanted as a whole organ. No procurement procedures were abandoned because of intraoperative technical complications, and no extrahepatic organs were jeopardized, allowing the regular procurement of kidneys, pancreas, hearts and lungs. The split liver procedures added 156 ± 33 minutes to the procurement when the left lateral segments were procured, while when the alternative technique was adopted the procedure required 185 ± 50 more minutes.
The demographics of the donors, vary according to the adopted procurement technique.