Utility of postsurgical renal scintigraphy to predict one-year outcome of renal transplants in patients with delayed graft function.

OBJECTIVE: Delayed graft function is a frequent complication after kidney transplantation impacting aversely on graft survival. The aim of this study was to assess the prognostic value of quantitative scintigraphic parameters immediately after transplantation in this population.
METHODS: One hundred patients with renal transplants suffering from delayed graft function were included in this study. All patients underwent Tc-mercaptoacetyltriglycine renal scintigraphy within 72 h of transplantation and were followed for 1 year. Various isotopic parameters were evaluated based on time-activity curves for angiographic and tubular phases. Threshold values for each parameter were derived from receiver operating characteristic curves to study their predictive values for transplant success at 1 year.
RESULTS: Mean values of the Kirchner index, tubular function slope, graft/aorta perfusion ratio, or graft uptake/perfusion ratio were significantly higher in successfully grafted patients (P<0.05). The Kirchner index yielded the largest area under the receiver operating characteristic curves (0.75). The tubular function slope (odds ratio>1.4) was found to be an independent prognostic factor for 1-year renal graft failure.
CONCLUSION: Our study confirms the prognostic value of vascular parameters in renal transplants, especially the Kirchner index whose negative predictive value was more than 90% for kidney transplantation 1-year success. In addition, isotopic parameters assessing the nephronic functional mass or the functional renal reserve seemed to be relevant prognostic tools with respect to 1-year outcomes. Therefore, the assessment of vascularization and renal function using an early Tc-mercaptoacetyltriglycine renal scintigraphy seems to be a powerful tool in establishing 1-year prognosis of renal allografts.