Urinary obstruction depresses erythropoiesis which recovers after parenchyma-saving surgery but not SWL

We tested the hypotheses that chronic human urinary obstruction impairs the renal regulation of the red blood cell (RBC) production and compared the chronic outcome of relief of obstruction between parenchyma-saving surgery and extracorporeal lithotripsy (SWL). We measured RBC count and serum erythropoietin (Epo) concentration before and 3 months after relief of urinary obstruction in 60 patients treated with pyelolithotomy, ureterolithotomy or ureteroscopy and in 62 patients treated with SWL. Compared with 333 healthy controls, at baseline, patients scheduled for parenchyma-saving surgery had lowered RBC count [9.9% (6.9-13.1); 95% confidence interval] in case of males and 17.7% (14.2-21.4) in case of females; minor depression in RBC count was also observed in female patients scheduled for SWL. Epo serum levels were mildly reduced in SWL patients and halved in parenchyma-saving surgery group. At 3 months following relief of obstruction in 50 operated patients without recurrent or residual stone, Epo levels almost doubled, becoming normal, while RBC count and haemoglobin concentration increased for 6.1% (3.8-8.8) and 8.8% (6.1-10.6). In contrast, in 49 SWL patients only minor, bidirectional responses to treatment were observed. We conclude that obstructive uropathy is associated with clinically relevant effects on erythropoiesis, which is reversed after relief of obstruction by parenchyma-saving surgery that saves the renal parenchyma.