The change of the split renal function before and after a nephrectomy using Tc-mercaptoacetyltriglycine (MAG3)

We examined the change in the renal function in the normal side kidney before and after a nephrectomy, by means of a newly developed diuretic renography technique utilizing Tc 99m-mercaptoacetyltriglycine (MAG3).

Forty patients who underwent a nephrectomy were evaluated using MAG3 diuretic renography. We measured the effective renal plasma flow (ERPF) and Tmax time before and after a nephrectomy. The effects of the patient age and the preoperative ERPF of ill side kidney on the post operative ERPF were then assessed statistically.

The ERPF increased by an average of 44.8 ml/min at 2 weeks after a nephrectomy, but it decreased by an average of 24.3 ml/min at 3 months after a nephrectomy. The Tmax time decreased by an average of 0.58 min at 2 weeks, but thereafter increased by an average of 0.58 min at 3 months after a nephrectomy. The correlation coefficient between the rate of increase in the ERPF and the patient age was 0.197.

The rise of renal function in terms of ERPF and the Tmax time was observed at 2 weeks post-nephrectomy. However, this effect disappeared at 3 months post-nephrectomy. These data demonstrated that the rise in the renal function of the normal-side kidney in such patients was only temporary.