Long-term outcome of surgical revascularization in ischemic nephropathy: normalization of average decline in renal function

Objective: Renovascular disease may lead to ischemia of the nephrons and to fibrosis, which is generally considered to be irreversible and progressive . We investigated the potential of revascularization to recover and stabili ze renal function in patients with ischemic nephropathy. Methods: In a retrospective analysis of all our 61 patients with ischemic n ephropathy who underwent treatment with surgical revascularization, we dete rmined the long-term course of renal function decline with an estimated glo merular filtration rate (EGFR; Cockcroft and Gault formula). With the assum ption of normal renal function at age 25 years, the preoperative slope of E GFR and the postoperative slope of EGFR were determined from the EGFR befor e surgery, at the short-term follow-up examination (on average, 8 months af ter surgery), and at the long-term follow-up examination (on average, at 47 months after surgery). These declines in renal function were compared with EGFR values in age-matched and sex-matched samples from a large cross-sect ional population study. Results: The overall surgical mortality rate amounted to 13.1%. Five patien ts became dialysis dependent-two with preexisting end-stage renal disease a nd three at later follow-up examination-and two patients, who before surger y were dialysis dependent, could be withdrawn from dialysis treatment. Shor tly after the operation, the mean EGFR level had increased from 28.3 to 43. 1 mL/min/1.73 m(2) (P < .01). The rate of decline in renal function had dec reased from an estimated -2.57 mL/min/1.73 m(2)/year before surgery (weight ed mean: interquartile range, -2.71 to -1.98) to -0.66 mL/min/1.73 m(2)/yea r (weighted mean: interquartile range, -2.00 to -0.18) in the short-term in terval to the long-term interval, which was even slightly better than the s lope of -0.84 mL/min/1.73 m2/year in the age-matched and sex-matched contro l population. Conclusion: Surgical revascularization in selected patients with renovascul ar disease and ischemic nephropathy restores renal function and makes the a verage long-term rate of decline in renal function equal to that of the gen eral population. This indicates that in most patients a "point-of-no-return " has not yet been passed even though their renal function is already marke dly impaired before surgery. Therefore, in well-selected patients with isch emic nephropathy, considerable improvement of renal function can be realize d.