Use of early postoperative MAG3 renal scan to predict long-term outcomes of renal transplants

Abstract

Objectives: A Tc-99m mercaptoacetyltriglycine renal scan has been used to evaluate perfusion and excretory function of renal allografts. A Tc-99m mercaptoacetyltriglycine renal scan has been reported to correlate with early allograft outcomes. This study was done to determine whether a Tc-99m mercaptoacetyltriglycine renal scan has any relation with long-term renal transplant outcomes.

Materials and methods: A total of 311 consecutive kidney transplant recipients were included in the study. All had Tc-99m mercaptoacetyltriglycine renal scans on posttransplant days 3 and 7. Patterns of the renography curve was graded as follows: 0=normal perfusion and excretion; 1=normal perfusion, reduced excretion; 2=normal perfusion, flat excretion; and 3=reduced perfusion and rising curve. Early postoperative Tc-99m mercaptoacetyltriglycine scintigraphy findings were correlated with serum creatinine values, acute rejection episodes, and long-term graft survival.

Results: A Tc-99m mercaptoacetyltriglycine renography of a deceased-donor kidney transplant showed a significantly higher grade on both days 3 and 7 than did live-donor kidney transplant (P < .001). Serum creatinine was positively correlated with the renography grades on days 3 and 7. The acute rejection rate was higher in the renography on days 3 and 7. Grade 2 renography on day 3 showed a significantly higher graft failure rate compared with the other grades (8.8% vs 8.6% vs 31.6% vs 7.3%; P = .014). Also, the renography showed the worst 5-year graft survival rate (95.9% vs 93.3% vs 89.5% vs 94.1%; P = .019). There were no differences in the graft failure rate or in graft survival rate according to the Tc-99m mercaptoacetyltriglycine renography grades on day 7.

Conclusions: Our data show that a Tc-99m mercaptoacetyltriglycine renography grade correlate not only with early postoperative kidney function and incidence of acute rejection, but also with long-term outcomes of a renal allograft. A grade 2 renography pattern, with normal uptake and flat excretion, indicates a dismal prognosis for the long-term allograft survival.