Abstract: Objective：To investigate the pathogenesis and therapy of hydronephrosis after hematopoietic stem cell transplantation (HSCT). Methods: From March 2004 to March 2014, 23 patients with hydronephrosis after HSCT were identified. With these data, the pathogenesis of hydronephrosis after HSCT were analyzed. According to the surgical intervention of hydronephrosis and ureteral dialation of ureteral stricture, the patients were divided into two groups, ranksum test and exact probability test were used to evaluate whether there were significant differences in the time of hemorrhagic cystitis (HC) occurred, ureteritis and viremia. Results: HC, ureteritis, ureteral stenosis were all the causes of hydronephrosis after HSCT. In this study, 69.6% (16/23) of the patients suffered from HSCT were cured by conservative treatment, 30.4% (7/23) by surgical intervention, and 13.0% (3/23) by insertion DJ stent or nephrostomy.Of the patients ［17.4% (4/23)］ who suffered ureteral stenosis, 2 were cured after the balloon dialation of ureter, 1 needed DJ tube longterm insertion, and 1 was still followed-up. Rank-sum test and exact probability test results showed that the patients who needed surgical intervention might suffer from HC later than other patients, and their incidences of viremia and ureteritis were higher, but the differences between the two groups were not statistically significant (P=0.524, P=0.169, and P=0.124, respectively). The results also showed that the ureteritis incidences of the patients who suffered from ureteral stricture and needed ureteral dialation were higher than that of the other patients, and the difference between the two groups was statistically significant (P=0.024). The patients who needed ureteral dialation suffered from HC later and their incidences of viremia was higher, but the differences between the two groups were not statistically significant (P=0.73 and P=0.27). Conclusion: HC, ureteritis and ureteral stenosis may cause hydronephrosis after HSCT. Patients may treated by conservative treatment first. Patients who suffered from HC later, viremia and especially ureteritis should be paid more attention to, and be treated with surgical intervention when necessary. The patients with ureteral stenosis could be treated by ureteral balloon dialation.

Key words: Hematopoietic stem cell transplantation, Hydronephrosis, Cystitis, Ureteral obstruction