title: Retrograde ureteroscopic endopyelotomy using the holmium:YAG laser.
abstract: OBJECTIVE
  We defined the safety and efficacy of retrograde ureteroscopic endopyelotomy using the holmium:YAG laser.
  
  
  METHODS
  Between July 1996 and December 1999 a total of 28 renal units in 21 women and 6 men 7 to 75 years old (mean age 43.5) with ureteropelvic junction obstruction were treated at our institution with retrograde ureteroscopic endopyelotomy. Ureteropelvic junction obstruction was bilateral in 1 case, primary in 20 and secondary in 8. Endoluminal ultrasound was done before endopyelotomy in all cases. Patients with renal calculi underwent antegrade percutaneous nephrostolithotomy and traditional cold knife endopyelotomy. Endoluminal ultrasound revealed posterior and lateral crossing vessels in 5 patients, who did not undergo the endoscopic approach. Retrograde endopyelotomy was performed using the holmium:YAG laser in 23 cases and electrode incision with pure cutting current in 5. Postoperatively a ureteral stent remained indwelling for an average of 6 weeks. Thereafter patients were followed with serial ultrasound, excretory urography and renal scan at 3 to 6-month intervals.
  
  
  RESULTS
  We evaluated 28 upper urinary tracts, including 19 (67.9%) with high insertion ureteropelvic junction obstruction and 9 with an annular stricture. As directed by ultrasound images, the incision location was posterolateral, posterior, lateral and posteromedial in 16, 5, 4 and 3 cases, respectively. Followup was available in all cases at a mean of 10 months (range 3 to 35). Success, defined as improved drainage on radiographic study and absent clinical symptoms, was achieved in 19 of the 23 patients (83%) treated with the holmium:YAG laser. Repeat laser incision resulted in a successful outcome in 2 of the 4 treatment failures. There were no acute surgical complications.
  
  
  CONCLUSIONS
  Retrograde ureteroscopic endopyelotomy with the holmium:YAG laser is safe and minimally invasive therapy for primary and secondary ureteropelvic junction obstruction. Endoluminal ultrasound aids in decision making when retrograde endopyelotomy is done.
authors.affiliation: Department of Urology, New York University Medical Center, New York University School of Medicine, New York, New York, USA.
authors.forename: J L
authors.initials: JL
authors.lastname: Giddens
authors.forename: M
authors.initials: M
authors.lastname: Grasso
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D004564:Electrocoagulation; D019160:Endosonography; D005260:Female; D006801:Humans; D007682:Kidney Pelvis / Q000000981:diagnostic imaging / Q000601:surgery*; D053685:Laser Therapy; D008297:Male; D008875:Middle Aged; D015607:Stents; D014517:Ureteral Obstruction / Q000000981:diagnostic imaging / Q000601:surgery*; D018666:Ureteroscopy