title: Robotic-assisted versus traditional laparoscopic partial nephrectomy: comparison of outcomes and evaluation of learning curve.
abstract: OBJECTIVE
  To examine the transition to robot-assisted laparoscopic partial nephrectomy (RALPN) from pure laparoscopic partial nephrectomy (LPN) and investigate the learning curve (LC). RALPN has emerged as a minimally invasive alternative to nephron-sparing surgery.
  
  
  METHODS
  A total of 150 consecutive patients were identified who underwent LPN or RALPN in the initial experience of a single surgeon since 2006. The perioperative data were evaluated using appropriate comparative tests. The LC was investigated by examining the operative times, warm ischemia times (WITs), and estimated blood loss (EBL) in groups of 25 consecutive patients. To account for laparoscopic LC, the outcomes of patients who underwent surgery in 2009 or later were also compared.
  
  
  RESULTS
  Of the 150 patients, 102 and 48 underwent LPN and RALPN, respectively. The patient and tumor characteristics were similar. The mean operative time (193 vs 152 minutes, P < .001), WIT (18.0 vs 14.0, P < .001), and EBL (245 vs 122 mL, P = .001) favored RALPN. Improvements in the operative time (P = .01), WIT (P = .006), and EBL (P = .01) were noted as experience increased in the LPN cohort and was most pronounced after the first 25 LPN patients. Since 2009, 55 and 44 patients underwent LPN and RALPN, respectively. Although the absolute differences were less, the operative time (182 vs 150, P < .001), WIT (15.3 vs 13.3, P < .001), and EBL (206 vs 118, P = .005) favored RALPN.
  
  
  CONCLUSIONS
  RALPN appears to have shorter operative and ischemia times and less blood loss compared with LPN. After a LC of approximately 25 cases, the transition from LPN to RALPN can be undertaken without an additional LC and can be associated with immediate benefits.
authors.affiliation: Brady Urological Institute, Johns Hopkins University, Baltimore, MD, USA. philpierorazio@jhmi.edu
authors.forename: Phillip M
authors.initials: PM
authors.lastname: Pierorazio
authors.forename: Hiten D
authors.initials: HD
authors.lastname: Patel
authors.forename: Tom
authors.initials: T
authors.lastname: Feng
authors.forename: Jithin
authors.initials: J
authors.lastname: Yohannan
authors.forename: Elias S
authors.initials: ES
authors.lastname: Hyams
authors.forename: Mohamad E
authors.initials: ME
authors.lastname: Allaf
mesh_terms: D000368:Aged; D002292:Carcinoma, Renal Cell / Q000601:surgery*; D005260:Female; D006801:Humans; D007511:Ischemia; D007680:Kidney Neoplasms / Q000601:surgery*; D010535:Laparoscopy / Q000379:methods*; D059032:Learning Curve; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D009392:Nephrectomy / Q000379:methods*; D011446:Prospective Studies; D012371:Robotics; D025321:Surgery, Computer-Assisted / Q000379:methods*; D014057:Tomography, X-Ray Computed / Q000379:methods; D016896:Treatment Outcome