The rationale for reconsidering organ donation from non–heart-beating cadavers has been the need to address the disparity between the demand and the supply of human allografts for transplantation. This shortage of organs is the major limiting factor in the number of renal and extrarenal transplants that are presently being performed. Therefore, the transplant program at the University of Pittsburgh Medical Center, in collaboration with the regional organ procurement organization, Center for Organ Recovery and Education (C.O.K.E.), has reexamined the suitability of procuring organs from NHBD. While we have concentrated on the recovery of kidneys and livers from these NHBD, there is also the potential to expand this program to include other organs.
The results of transplantation of NHBD kidney allografts compared favorably with those of HBD. At the University of Pittsburgh, one-year kidney patient and graft survivals in the overall NHBD kidney experience were 90% and 85%, respectively. The one-year patient and graft survivals for kidneys obtained from HBD during the same period were 93% and 80%, respectively. This was not statistically significant (), On the, other hand, the results for NHBD liver allografts were poorer than those for HBD, however, given the small number of patients in both G1 and G2, clinically relevant comparisons could not be made.
Under routine conditions of brain death pronouncement, and with modern techniques of multiple organ procurement (8
) there is virtually no preoperative warm ischemia. Maintenance of cardiorespiratory function in the absence of brain function has been a major advance in reducing ischemic injury to organ allografts. In contrast, acquisition of organs from NHBD is not performed under ideal conditions, as no cardiac or respiratory activity is present for a variable period prior to organ recovery. Consequently, these organs are subjected to some warm ischemia time; the period of hypoxia and lack of effective circulation is even more pronounced in patients in whom CPR was started before recovery. Therefore, it would be anticipated that the impact of a period of warm ischemia would be even more pronounced than an equal period of warm ischemia seen in other types of liver surgery. There were no differences in the rewarming ischemia time during implantation between G1, G2 and HBD (data not shown).
In both controlled and uncontrolled situations, the procurement of livers and kidneys must be accomplished quickly, and this should be performed only by an experienced surgical team. The urgent time frame in which organs are procured from uncontrolled NHBD makes these the most difficult of all donor situations. The most important principle of the so-called super-rapid technique is that the organs must be rapidly cooled prior to any attempts at the dissection.
An initial assessment of the quality of the liver was done by the donor surgeon. In most of the hemodynamically unstable donors the livers were inhomogeneously cyanotic and showed signs of congestion as a result of a partial outflow blockage of the abdominal viscera caused by CPR maneuvers. This finding disappeared after cold perfusion in all livers with one exception. This liver was discarded because of gross evidence of hypoperfusion. When donor surgeons had any doubts about the viability of the livers, frozen section biopsies were performed. In all cases where the surgeons considered the liver unsuitable, the frozen section was confirmatory. Five of the liver allografts that were transplanted had both a back table and postreperfusion biopsy. The results of these pretransplant and posttransplant biopsies were then correlated with ultimate graft outcome to see if, in retrospect, a different decision would have been made about the suitability of the graft for transplantation. Two biopsied livers had a gross and histologically normal appearance before transplantation and developed PNF. This inability to predict organ function uniformly after transplantation by light microscopic examination of biopsy specimens has been widely discussed in the literature (10
While all attempts were made to limit preoperative warm ischemia, the mean period of preoperative warm ischemia was 37 (range 10–100) min for uncontrolled NHBD and 24 (range 10–92) min for controlled NHBD. Renal transplantation from NHBD has been reported to have a high incidence of both ATN and vascular complications. One report shows that 10% of the kidneys developed thrombotic microangiopathy, which was attributed to a warm ischemic injury to the renal microvasculature (14
). While the kidneys procured in our series did not have a high incidence of arterial complications, a similar pathophysiology in the procured livers may explain the high incidence of PNF and HAT. Diagnosis of HAT accounts for less than 10% of early graft failures in organs recovered from HBD (15
). In our series, 3 of 12 patients (25%) developed HAT and required retransplantation; two of these patients eventually died. Although these complications were classified as technical errors, it is possible that hepatic preservation/reperfusion injury played a role in these events.
The warm ischemia and the inevitable cold preservation are well-known factors that cause injury to the parenchymal and nonparenchymal liver cells, in particular the Kupffer cells and sinusoidal cells of the microvasculature. The degree of this damage and that performed by the reperfusion mechanism can result in local clotting of the hepatic microvasculature (10
This study attempted to delineate the circumstances in which renal and extrarenal organs can be procured from NHBD. Our data confirm that the procurement of kidneys from both uncontrolled and controlled NHBD leads to acceptable graft function, despite a high incidence of ATN. These results compare favorably with other reported attempts at using kidneys from NHBD. Yokoyama et al., using the in situ perfusion technique of kidneys in NHBD, reported a one-year patients and graft survival of 85%, with an ATN rate of 75% (16
). Varty et al., also using a double-balloon catheter reported an overall 75% graft survival (17
). It appears that the results of using organs from NHBD depends on factors inherent in minimizing warm ischemic injury. Phillips et al, obtained less-favorable results in NHBD with prolonged warm ischemia times (18
In the controlled NHBD, immediate good liver allograft function can be anticipated—however, liver allografts from uncontrolled NHBD have a high incidence of PNF. The increased rate of arterial complications in livers from NHBD remains unexplained. Further studies and experience in this group of liver donors may help elucidate the mechanism of both PNF and HAT.
In summary, NHBD represent a viable source of cadaveric kidneys but must be carefully assessed as to their appropriateness for liver usage.