title: Novel dual-lumen ureteral stents provide better ureteral flow than single ureteral stent in ex vivo porcine kidney model of extrinsic ureteral obstruction.
abstract: OBJECTIVE
  In the instance of extrinsic ureteral obstruction, indwelling ureteral stents have a high failure rate. Although technically challenging, simultaneous insertion of two ipsilateral stents can achieve better flow rates with time. A novel dual-lumen stent, composed of two adhered ureteral stents, offers the additional benefit of easier placement than a single guidewire. Using a novel ex vivo porcine model, the flow rates within an extrinsically obstructed renal unit were evaluated using two internal ipsilateral stents and two prototype double-lumen stents.
  
  
  METHODS
  Sixteen renal units were harvested from eight adult Yorkshire female pigs. To quantify flow, the kidneys were infused at a constant pressure, and the corresponding ureteral drainage was measured for a defined interval. The flow was measured with a standard 7F double-pigtail stent, two ipsilateral 7F double-pigtail stents, a 7F novel double-lumen stent designed with both distal lumens open, and a 7F novel double-lumen stent with one distal lumen closed. The intraluminal and extraluminal flow in obstructed and nonobstructed systems was measured.
  
  
  RESULTS
  The two ipsilateral standard stents or prototype double stents achieved better flow down the ureter than did one standard stent (P <0.05). The intraluminal and extraluminal flow in the novel stents was statistically greater than the corresponding flow in the standard double-pigtail stent (P <0.01). The extraluminal and obstructed flow was lowest for the standard double-pigtail stent.
  
  
  CONCLUSIONS
  Novel dual-lumen prototype ureteral stents provided better flow than a single stent in extrinsically obstructed ureters with the proposed added benefit of easier retrograde insertion compared with a single guidewire.
authors.affiliation: Department of Urology, Montefiore Medical Center/Albert Einstein College of Medicine, Bronx, New York, USA.
authors.forename: Jason
authors.initials: J
authors.lastname: Hafron
authors.forename: Michael C
authors.initials: MC
authors.lastname: Ost
authors.forename: Beng Jit
authors.initials: BJ
authors.lastname: Tan
authors.forename: James D
authors.initials: JD
authors.lastname: Fogarty
authors.forename: David M
authors.initials: DM
authors.lastname: Hoenig
authors.forename: Benjamin R
authors.initials: BR
authors.lastname: Lee
authors.forename: Arthur D
authors.initials: AD
authors.lastname: Smith
mesh_terms: D000818:Animals; D021721:Balloon Occlusion; D004195:Disease Models, Animal; D005260:Female; D015607:Stents; D013552:Swine; D014515:Ureteral Diseases / Q000150:complications* / Q000503:physiopathology; D016055:Urinary Retention / Q000209:etiology / Q000503:physiopathology / Q000601:surgery*; D014563:Urodynamics