title: The learning curve for robot-assisted radical cystectomy.
abstract: OBJECTIVE
  Robot-assisted radical cystectomy has the potential to cure patients from bladder cancer while offering the benefits of minimally invasive surgery. We sought to evaluate the learning curve for this technically demanding procedure.
  
  
  METHODS
  Robot-assisted radical cystectomy was attempted in 100 consecutive patients. An IRB-approved review of our robot-assisted radical cystectomy database was conducted. Total operative (OR) time, cystectomy time, pelvic lymph node dissection (PLND) time, estimated blood loss (EBL), margin positivity, complications, and length of hospital stay were compared among patients divided into 4 cohorts of increasing surgical experience. Scattergrams and continuous curves were plotted to develop a robotic cystectomy learning curve.
  
  
  RESULTS
  Overall OR time decreased from 375 minutes in cohort 1 to 352 minutes in cohort 4, with less than 1% change in OR time after case 16. Time from incision to bladder extirpation decreased from 187 minutes in cohort one to 165 minutes in cohort 4. Time for PLND increased from 44 minutes in cohort 1 to 77 minutes in cohort 4. Lymph node yield increased from 14 nodes in cohort 1 to 23 nodes in cohort 4. Positive surgical margins decreased from 4 patients in cohort 1 to 0 patient in cohort 4. The complication rate had no change from 9 patients in cohort 1 to 9 patients in cohort 4.
  
  
  CONCLUSIONS
  Operative results and oncologic outcomes for robot-assisted radical cystectomy constantly improve as the technique evolves.
authors.affiliation: Department of Urologic Oncology, Roswell Park Cancer Institute, Buffalo, New York 14263, USA. khurshid.guru@roswellpark.org
authors.forename: Khurshid A
authors.initials: KA
authors.lastname: Guru
authors.forename: Adam E
authors.initials: AE
authors.lastname: Perlmutter
authors.forename: Zubair M
authors.initials: ZM
authors.lastname: Butt
authors.forename: Pamela
authors.initials: P
authors.lastname: Piacente
authors.forename: Gregory E
authors.initials: GE
authors.lastname: Wilding
authors.forename: Wei
authors.initials: W
authors.lastname: Tan
authors.forename: Hyung L
authors.initials: HL
authors.lastname: Kim
authors.forename: James L
authors.initials: JL
authors.lastname: Mohler
mesh_terms: D016063:Blood Loss, Surgical / Q000706:statistics & numerical data; D016009:Chi-Square Distribution; D015653:Cystectomy / Q000295:instrumentation* / Q000379:methods; D005260:Female; D006801:Humans; D016018:Least-Squares Analysis; D007902:Length of Stay / Q000706:statistics & numerical data; D008197:Lymph Node Excision / Q000295:instrumentation / Q000379:methods; D008297:Male; D011446:Prospective Studies; D012189:Retrospective Studies; D012371:Robotics / Q000295:instrumentation* / Q000379:methods; D013997:Time Factors; D016896:Treatment Outcome; D001749:Urinary Bladder Neoplasms / Q000601:surgery*