Evaluating the outcome of percutaneous transluminal angioplasty in renal graft artery stenosis using the areas under the time curve of glomerular filtration rate and blood pressure

The benefit of percutaneous transluminal angioplasty (PTA) of transplant re nal artery stenosis for ischemic nephropathy may be adversely affected by r ejection or other complications. As a result, assessment of the effect of P TA on renal function or blood pressure is often difficult. In this paper, w e evaluated the effect of PTA using the method of integrated glomerular fil tration rate (GFR) based upon the area under the curve over a follow-up per iod (AUC(0-t)), to express the level of GFR in a simple manner despite its significant fluctuations. A similar procedure was used to evaluate mean art erial pressure (MAP). The method was employed to assess the outcome in 20 i ndividuals before PTA, and 1, 3, 6, 9 and 12 months after PTA. In eight cas es, rejection was detected while there was one case of glomerulonephritis i n the graft during the follow-up period. Evaluation (AUC(Cer))(0-12) relate d to the integrated pre-PTA value of C-er [(C-cr)(0) x 12] revealed a rise in GFR by more than 20% in 65% of cases. No improvement was observed in sev en individuals with post-PTA complications. When assessing the integrated v alue of MAP, success of PTA (a reduction by at least 10%) was found in 85% of cases. No significant correlation was found between the relative changes of integrated GFR and MAP. Our data suggest that evaluation of the integra ted value of GFR or MAP on the basis of AUC(0-t) allows to characterize, in a simple manner, the level of graft function and MAP throughout the follow -up period in individual cases. Furthermore, it may provide additional info rmation on the average values obtained at different time intervals after th e therapeutic procedure.