Segmental infarction with graft dysfunction: an emerging syndrome in renal transplantation?
BACKGROUND: Segmental allograft infarction is a poorly characterized complication following renal transplantation. The present study was undertaken with the goal of defining the incidence, clinical characteristics, pathogenesis, and prognosis of this entity. METHODS: A retrospective study was performed, reviewing the renal scans performed on all renal transplant recipients at our institution, from January 1997 to January 2000. Segmental infarction was diagnosed on the basis of a significant elevation in lactate dehydrogenase (>500 U/l) together with a photopenic perfusion defect. In these patients, graft characteristics, operative details, clinical course, and long-term outcomes were evaluated. RESULTS: Segmental infarction was identified in 13 of 277 consecutive renal transplant recipients (4.7%). In nine recipients the onset of infarction occurred within 24 h after transplantation. All received marginal grafts, and in five recipients the transplant operation was complicated by major blood loss. Eight of these recipients exhibited primary non-function, or developed dialysis-dependent renal failure after the onset of infarction. In four patients, the onset of infarction occurred after 24 h (35 h to 10 days). One recipient demonstrated primary non-function, and renal function deteriorated after the onset of infarction in the remaining three. Overall, long-term graft function was impaired. Two allografts never functioned, and six recipients had nadir creatinine clearances below 60 ml/min. CONCLUSIONS: The pathogenesis of segmental infarction appears to be multi-factorial, reflecting the combination of an initiating anatomic lesion and potentiating thrombogenic milieu. Segmental infarction typically occurs in the early postoperative period, and prompt diagnosis is difficult to obtain. In view of this, prophylactic heparin may be warranted for those at highest risk. There was no correlation between the infarct area and the graft function, and the long-term graft function is compromised out of proportion to the extent of parenchymal loss. This finding highlights the role of predisposing factors, particularly marginal graft quality, in determining the functional outcome. Segmental infarction may be more frequently encountered as cadaveric organ shortages encourage greater use of marginal donor kidneys.