title: [Duplex ureteral stenting for intrinsic and extrinsic ureteral strictures: an effective and elegant alternative].
abstract: BACKGROUND
  Duplex or twin ureteral stenting has previously been described as a viable option for patients where single double-J ureteral stenting has failed in order to avoid nephrostomies or further surgical intervention. We assessed a series of 20 patients at our institution after unsuccessful primary single ureteral stenting where parallel ureteral stents were inserted.
  
  
  METHODS
  Between 2003 and 2009, 20 patients underwent double-J ureteral stenting for ureteral compression or ureteral strictures. After failure of single stenting two ureteral stents were consecutively inserted into the ureter in a parallel fashion after dilating the ureter up to 14 F. The second stent was passed over a hydrophilic guidewire while holding the first stent secure to prevent dislocation.
  
  
  RESULTS
  In all patients the insertion of two parallel stents was technically possible. In 8 of 12 patients with extrinsic tumor compression the stents provided sufficient drainage (67%). When the stricture was due to surgery or radiation two of three patients were successfully diverted with twin stents. In five patients with a ureteral stricture due to malignant disease the stenting did not provide sufficient drainage and a nephrostomy had to be placed after a mean duration of 19 days. Two of those patients were later managed with a pyelovesical bypass. Three patients were later managed with a ureterocystoneostomy (psoas hitch). In four of five patients with benign disease a long-term management was feasible. The patient with retroperitoneal fibrosis developed immediate hydronephrosis and severe flank pain and ultimately underwent an ileal ureter replacement. In three patients with a benign ureteral stenosis after stone therapy, hysterectomy, or colon ureter replacement, a temporary duplex stenting sufficiently resolved the hydronephrosis for spontaneous urine passage. In one patient the duplex stenting prevented a kidney stone from dislocating into the ureter during lithotripsy.
  
  
  CONCLUSIONS
  Duplex or twin (double) ureteral stenting is a valid option in selected patients to avoid the placement of a nephrostomy. Severe stenosis may however demand a nephrostomy insertion or more invasive procedures in the later course. For certain benign ureteral strictures a therapeutic dilating effect of the two ureteral stents that makes further intervention unnecessary can be discussed.
authors.affiliation: Klinik für Urologie und Kinderurologie, Helios-Klinikum Wuppertal, Universität Witten-Herdecke, Heusner Strasse 40, 42283, Wuppertal, Deutschland. fvonrundstedt@googlemail.com
authors.forename: F-C
authors.initials: FC
authors.lastname: von Rundstedt
authors.forename: D
authors.initials: D
authors.lastname: Lazica
authors.forename: A S
authors.initials: AS
authors.lastname: Brandt
authors.forename: M
authors.initials: M
authors.lastname: Rathert
authors.forename: S
authors.initials: S
authors.lastname: Roth
mesh_terms: D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011474:Prosthesis Design; D015607:Stents; D016896:Treatment Outcome; D014525:Urethral Stricture / Q000601:surgery*; D013520:Urologic Surgical Procedures / Q000295:instrumentation*