title: Evaluation of renal function in patients with a main renal stone larger than 1 cm and perioperative renal functional change in minimally invasive renal stone surgery: a prospective, observational study.
abstract: OBJECTIVE
  To compare the perioperative relative renal function and determine predictors of deterioration and recovery of separate renal function in patients with renal stones >10 mm and who underwent mini-percutaneous nephrolithotomy or retrograde intra-renal surgery.
  
  
  METHODS
  A main stone >10 mm or stones growing, high-risk stone formers and extracorporeal shock-wave lithotripsy-resistant stones were prospectively included in 148 patients. Patients with bilateral renal stones and anatomical deformities were excluded. Renal function was evaluated by estimated glomerular filtration rate, 99m-technetium dimercaptosuccinic acid and 99m-technetium diethylenetriamine pentaacetate prior to intervention and at postoperative 3 months. Logistic regression analyses were performed to find predictors of functional deterioration and recovery.
  
  
  RESULTS
  The overall stone-free rate was 85.1 %. A third of patients (53/148, 35.8 %) with renal stones >10 mm showed deterioration of separate renal function. Mean renal function of operative sites showed 58.2 % (36.8 %/63.2 %) of that of contralateral sites in these patients. Abnormal separate renal function showed postoperative recovery in 31 patients (58.5 %). Three cases (5.7 %) showed deterioration of separate renal function despite no presence of remnant stones. Improvement rates of the abnormal separate renal function did not differ according to the type of surgery. The presence of hydronephrosis and three or more stones were significant predictors for renal function deterioration. Female gender and three or more stones were significantly correlated with postoperative recovery.
  
  
  CONCLUSIONS
  Mini-percutaneous nephrolithotomy or retrograde intra-renal surgery was effective and safe for renal function preservation. Patients with multiple large stones should be considered for candidates of active surgical removal.
authors.affiliation: Department of Urology, Seoul National University Hospital, Seoul, Republic of Korea.|Department of Urology, Yanbian University Hospital, Yanji, Jilin, China.
authors.forename: Songzhe
authors.initials: S
authors.lastname: Piao
authors.affiliation: Department of Urology, SMG-SNU Boramae Medical Center, Sindaebang 2-dong, 395, Dongjak-gu, Seoul, 156-707, Republic of Korea.
authors.forename: Juhyun
authors.initials: J
authors.lastname: Park
authors.affiliation: Department of Urology, SMG-SNU Boramae Medical Center, Sindaebang 2-dong, 395, Dongjak-gu, Seoul, 156-707, Republic of Korea.
authors.forename: Hwancheol
authors.initials: H
authors.lastname: Son
authors.affiliation: Department of Urology, SMG-SNU Boramae Medical Center, Sindaebang 2-dong, 395, Dongjak-gu, Seoul, 156-707, Republic of Korea.
authors.forename: Hyeon
authors.initials: H
authors.lastname: Jeong
authors.affiliation: Department of Urology, SMG-SNU Boramae Medical Center, Sindaebang 2-dong, 395, Dongjak-gu, Seoul, 156-707, Republic of Korea. kmoretry@daum.net.
authors.forename: Sung Yong
authors.initials: SY
authors.lastname: Cho
mesh_terms: D005260:Female; D006801:Humans; D007669:Kidney Calculi / Q000473:pathology / Q000503:physiopathology* / Q000601:surgery*; D007677:Kidney Function Tests; D008297:Male; D008875:Middle Aged; D019060:Minimally Invasive Surgical Procedures; D009403:Nephrostomy, Percutaneous; D059035:Perioperative Period; D011446:Prospective Studies
keywords: Gadolinium DTPA; Kidney calculi; Kidney function tests; Laser; Lithotripsy; Nephrostomy; Percutaneous; Technetium 99m dimercaptosuccinic acid; Urolithiasis