title: Is One Early Renographic Follow-Up Adequate to Measure the Success of Robotic Pyeloplasty?
abstract: Diuretic renography (DRG) is commonly used to diagnose ureteropelvic junction obstruction (UPJO) and to evaluate the success of surgical repair (pyeloplasty). Duration, frequency, and interpretation of renographic follow-ups are still under dispute.
  
  
  
  We retrospectively reviewed 94 consecutive patients diagnosed with UPJO who underwent a minimally invasive, robotically assisted laparoscopic pyeloplasty at our institution between January 2009 and September 2015. DRG was carried out preoperatively and again routinely 4 to 6 weeks postoperatively the day after stent removal (early DRG). Patients were scheduled for repeat (late) DRG and follow-up examinations, including clinical status and ultrasonography.
  
  
  
  Nineteen patients with missing preoperative DRG were excluded from the study; the remaining 75 patients were eligible for statistical evaluation. At follow-up, 98.7% reported no or only very mild and rare symptoms. On early DRG, 52.5% had T1/2≤ 10 min (unobstructed), 39.3% had T1/2between 10 and 20 minutes (equivocal), and 8.2% had T1/2≤ 20 minutes (obstructed). At late follow-up, the DRG results had improved to 80.8% unobstructed with 19.2% remaining equivocal, and no patients were obstructed; thus, the overall success rate was 80.8%. There was only one patient who worsened from unobstructed to equivocal from early to late DRG assessment.
  
  
  
  In case of complete symptom resolution, a nonobstructive diuretic half-time of ≤10 minutes on early DRG following stent removal suggests that further routine renographic follow-up is unnecessary. Patients with an equivocal early DRG (T1/2between 10 and 20 minutes) require further scintigraphic follow-up, as they have a 42.1% chance of staying equivocal.
authors.affiliation: 1 Department of Urology, Augusta-Kranken-Anstalt gGmbH , Bochum, Germany .
authors.forename: Alexander
authors.initials: A
authors.lastname: Roosen
authors.affiliation: 1 Department of Urology, Augusta-Kranken-Anstalt gGmbH , Bochum, Germany .
authors.forename: Cagatay
authors.initials: C
authors.lastname: Dogan
authors.affiliation: 1 Department of Urology, Augusta-Kranken-Anstalt gGmbH , Bochum, Germany .
authors.forename: Huy Hoang
authors.initials: HH
authors.lastname: Nguyen
authors.affiliation: 1 Department of Urology, Augusta-Kranken-Anstalt gGmbH , Bochum, Germany .
authors.forename: Markus
authors.initials: M
authors.lastname: Heiland
authors.affiliation: 2 Department of Radiology and Nuclear Medicine, Augusta-Kranken-Anstalt gGmbH , Bochum, Germany .
authors.forename: Detlev
authors.initials: D
authors.lastname: Longwitz
authors.affiliation: 1 Department of Urology, Augusta-Kranken-Anstalt gGmbH , Bochum, Germany .
authors.forename: Burkhard
authors.initials: B
authors.lastname: Ubrig
mesh_terms: D000328:Adult; D020878:Device Removal; D004232:Diuretics; D004724:Endoscopy; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007668:Kidney / Q000601:surgery; D007682:Kidney Pelvis / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D019060:Minimally Invasive Surgical Procedures; D011184:Postoperative Period; D011866:Radioisotope Renography; D019651:Plastic Surgery Procedures; D012189:Retrospective Studies; D065287:Robotic Surgical Procedures; D015607:Stents; D016896:Treatment Outcome; D014513:Ureter / Q000601:surgery*; D014517:Ureteral Obstruction / Q000601:surgery*
chemical_list: D004232:Diuretics
keywords: diuretic renography; robotic pyeloplasty; ureteropelvic junction occlusion