title: Factors affecting operative time during percutaneous nephrolithotomy: our experience with the complete supine position.
abstract: OBJECTIVE
  Operative time influences surgical outcomes, operation-related and indirectly anesthesia-related complications. We investigated variables that affect operative time during percutaneous nephrolithotomy (PCNL) with the complete supine position.
  
  
  METHODS
  We reviewed data of 120 patients who underwent complete supine PCNL by one surgeon. Correlation between age, sex, body mass index (BMI), preoperative serum creatinine and hemoglobin levels, history (stone surgery, shockwave lithotripsy (SWL), hypertension, diabetes), stone (side, opacity, burden, complexity), imaging for access, calix for access, number of tracts, and tubeless approach with operative time were assessed by univariate and multivariate statistical tests.
  
  
  RESULTS
  Mean operative time was 60.62±30.70 minutes. In univariate analysis, age, sex, groups of BMI, hypertension, diabetes, previous stone surgery and SWL, stone opacity, operation side, number of tracts, and tubeless approach had no effect on operative time. BMI (P=0.029, negative correlation), stone burden (P=0.001, positive correlation), imaging for access (P=0.001, fluoroscopy<ultrasonography), calix for access (P=0.035, upper>lower>middle) and probably complex stones (P=0.057, complex>noncomplex) were effective factors on operative time. Multiple linear regression revealed association between BMI (P=0.000, negative correlation), stone burden (P=0.005, positive correlation), imaging for access (P=0.000, fluoroscopy<ultrasonography), and calix for access (P=0.023) with operative time. In lower calix access, mean operative time was less than upper calix access (P=0.022, significant) and higher than middle calix access (P=0.930, nonsignificant).
  
  
  CONCLUSIONS
  BMI, stone burden, imaging for access, and calix for access were effective parameters on operative time in complete supine PCNL. Groups of BMI, previous stone surgery and SWL, number of tracts, and tubeless approach had no effect on operative time.
authors: Urology Research Center, Razi Hospital, Guilan University of Medical Science, Rasht, I.R. Iran.
authors: Siavash
authors: S
authors: Falahatkar
authors: Keivan Gholamjani
authors: KG
authors: Moghaddam
authors: Ehsan
authors: E
authors: Kazemnezhad
authors: Ahmad
authors: A
authors: Enshaei
authors: Ahmad
authors: A
authors: Asadollahzade
authors: Alireza
authors: A
authors: Farzan
authors: Reza Shahrokhi
authors: RS
authors: Damavand
authors: Hamidreza Baghani
authors: HB
authors: Aval
authors: Somayeh
authors: S
authors: Khodabakhsh
authors: Samaneh
authors: S
authors: Esmaeili
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D007669:Kidney Calculi / Q000601:surgery*; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D009403:Nephrostomy, Percutaneous / Q000379:methods*; D016683:Supine Position; D013997:Time Factors; D055815:Young Adult