[Ureteral stenosis following hematopoietic stem cell transplantation: A case report].

Ureteral stenosis is a comparatively rare complication following hematopoietic stem cell transplantation (HSCT). The etiology is still unclear and most believe that this may be due to the reactivation of BK virus in a state of immunodeficiency. In the later stages of ureteral stenosis with scarring, invasive interventions must be taken to relieve the hydronephrosis. Common treatments, such as D-J stent placement and permanent nephrostomy may not only entail the risk of infection, but also seriously affect the quality of life. Few cases of surgical intervention have been reported. In this article, a 25-year-old female was admitted to Peking University First Hospital suffering from recurrent flank pain. Seven years before, she developed hemorrhagic cystitis and bilateral urethritis 40 days after allogeneic HSCT. After continuous bladder irrigation and antiviral therapy, the left-sided hydronephrosis gradually alleviated while the right-sided one did not improve. D-J stents were used for urine drainage for 7 years before percuta-neous nephrostomy. Preoperative antegrade pyelography revealed significant hydronephrosis in the right kidney with long stricture of proximal-middle ureter. After comprehensive decision, she underwent ileal ureter replacement. The operation was successful. The segmental lesion was dissected and the scar tissue was removed. A 25 cm intestinal tube was isolated to connect the pelvis and bladder. An anti-reflux nipple was created at the distal end of ileal ureter to prevent the potential infection. The blood loss was minimal. After surgery, the drainage tube was removed in 2 weeks, the nephrostomy tube and the D-J stent was removed in 3 months. Follow-up mainly included clinical assessment, serologic testing, renal ultrasonography, blood gas analysis and radiological examination. During the follow-up of 6 years, she was symptom-free and no postoperative complications occurred. The serum creatinine level was stable. No hydronephrosis was observed under ultrasonography. Obvious peristaltic waves and ureteral jets of the ileal ureter was confirmed on cine magnetic resonance urography. To sum up, ureteral stenosis after HSCT is relatively rare. Obstruction caused by scarring is usually irreversible and surgical intervention should be designed according to the location and length of the lesion. Ileal ureter replacement can be a safe, feasible and effective method to solve this kind of complex stricture.