title: Robot-assisted versus open radical prostatectomy: the differential effect of regionalization, procedure volume and operative approach.
abstract: OBJECTIVE
  The use of robot-assisted radical prostatectomy has increased rapidly despite the absence of randomized, controlled trials showing the superiority of this approach. While recent studies suggest an advantage for perioperative complication rates, they fail to account for the volume-outcome relationship. We compared perioperative outcomes after robot-assisted and open radical prostatectomy, while considering the impact of this established relationship.
  
  
  METHODS
  Using the NIS (Nationwide Inpatient Sample), we abstracted data on patients treated with radical prostatectomy in 2009. Univariable and multivariable logistic regression analyses were done to compare the rates of blood transfusion, intraoperative and postoperative complications, prolonged length of stay, increased hospital charges and mortality between robot-assisted and open radical prostatectomy overall and across volume quartiles.
  
  
  RESULTS
  An estimated 77,616 men underwent radical prostatectomy, including a robot-assisted and an open procedure in 63.9% and 36.1%, respectively. Low volume centers averaged 26.2 robot-assisted and 5.2 open cases, while very high volume centers averaged 578.8 robot-assisted and 150.2 open cases. Overall, patients treated with the robot-assisted procedure experienced a lower rate of adverse outcomes than those treated with the open procedure for all measured categories. Across equivalent volume quartiles robot-assisted radical prostatectomy outcomes were generally favorable. However, the open procedure at high volume centers resulted in a lower postoperative complication rate (OR 0.59, 95% CI 0.46-0.75), elevated hospital charges (OR 0.75, 95% CI 0.64-0.87) and a comparable blood transfusion rate (OR 1.38, 95% CI 0.93-2.02) relative to the robot-assisted procedure at low volume centers.
  
  
  CONCLUSIONS
  Regionalization has occurred to a greater extent for robot-assisted than for open radical prostatectomy with an associated benefit in overall outcomes. Nonetheless, low volume institutions experienced inferior outcomes relative to the highest volume centers irrespective of approach. These findings demonstrate the importance of accounting for hospital volume when examining the benefit of a surgical technique.
authors.affiliation: Vattikuti Urology Institute, Henry Ford Health System, Detroit, Michigan 48202, USA. jsammon1@hfhs.org
authors.forename: Jesse D
authors.initials: JD
authors.lastname: Sammon
authors.forename: Pierre I
authors.initials: PI
authors.lastname: Karakiewicz
authors.forename: Maxine
authors.initials: M
authors.lastname: Sun
authors.forename: Shyam
authors.initials: S
authors.lastname: Sukumar
authors.forename: Praful
authors.initials: P
authors.lastname: Ravi
authors.forename: Khurshid R
authors.initials: KR
authors.lastname: Ghani
authors.forename: Marco
authors.initials: M
authors.lastname: Bianchi
authors.forename: James O
authors.initials: JO
authors.lastname: Peabody
authors.forename: Shahrokh F
authors.initials: SF
authors.lastname: Shariat
authors.forename: Paul
authors.initials: P
authors.lastname: Perrotte
authors.forename: Jim C
authors.initials: JC
authors.lastname: Hu
authors.forename: Mani
authors.initials: M
authors.lastname: Menon
authors.forename: Quoc-Dien
authors.initials: QD
authors.lastname: Trinh
mesh_terms: D000368:Aged; D061847:Hospitals, High-Volume; D061846:Hospitals, Low-Volume; D006801:Humans; D008297:Male; D008875:Middle Aged; D010043:Outcome and Process Assessment, Health Care; D011183:Postoperative Complications / Q000453:epidemiology / Q000209:etiology; D011468:Prostatectomy / Q000009:adverse effects / Q000379:methods* / Q000706:statistics & numerical data*; D011471:Prostatic Neoplasms / Q000601:surgery*; D012371:Robotics / Q000706:statistics & numerical data*