title: Missed anterior crossing vessels during open retroperitoneal pyeloplasty: laparoscopic transperitoneal discovery and repair.
abstract: OBJECTIVE
  Extrinsic ureteropelvic junction obstruction due to anterior crossing segmental renal vessels is present in more than 50% of patients in adulthood. In this situation the ureter must usually be dismembered and transposed anterior to the crossing vascular structures, where it is anastomosed to the renal pelvis. Via the open retroperitoneal approach there may be a limited view of the anterior surface of the ureteropelvic junction and, hence, anterior crossing vessels may possibly be missed. We describe 2 patients with ureteropelvic junction obstruction in whom anterior vessels were missed during open retroperitoneal repair. Laparoscopic transperitoneal secondary pyeloplasty with posterior displacement of the crossing renal vessel was performed in each case.
  
  
  METHODS
  Two patients presented with symptomatic congenital ureteropelvic junction obstruction after failed endopyelotomy in 1 and failed open retroperitoneal procedures in both. Preoperatively spiral computerized tomography angiography with a ureteropelvic junction protocol revealed crossing vessels in the 2 cases. This finding was confirmed at transperitoneal laparoscopic pyeloplasty. The ureter and renal pelvis were transposed anterior to the crossing vessels and 2 rows of running sutures were placed to complete the anastomosis.
  
  
  RESULTS
  The 2 laparoscopic procedures were completed successfully. The anterior crossing vessels were preserved in each case. Currently the patients are asymptomatic and furosemide washout renal scan was normal.
  
  
  CONCLUSIONS
  Spiral CT angiography reliably delineates the renal vascular anatomy in patients with ureteropelvic junction obstruction. This study may be valuable before planned open retroperitoneal ureteropelvic junction obstruction repair. Laparoscopic pyeloplasty may successfully manage anterior crossing vessels associated with secondary ureteropelvic junction obstruction.
authors.affiliation: Department of Surgery (Division of Urologic Surgery), Washington University School of Medicine, St. Louis, Missouri, USA.
authors.forename: J
authors.initials: J
authors.lastname: Rehman
authors.forename: J
authors.initials: J
authors.lastname: Landman
authors.forename: C
authors.initials: C
authors.lastname: Sundaram
authors.forename: R V
authors.initials: RV
authors.lastname: Clayman
mesh_terms: D000293:Adolescent; D000792:Angiography; D001808:Blood Vessels / Q000002:abnormalities; D005260:Female; D006801:Humans; D007682:Kidney Pelvis / Q000098:blood supply* / Q000601:surgery*; D010535:Laparoscopy; D008297:Male; D008875:Middle Aged; D012086:Reoperation; D014057:Tomography, X-Ray Computed; D014517:Ureteral Obstruction / Q000601:surgery; D014570:Urologic Diseases / Q000151:congenital / Q000601:surgery