title: Transperitoneal robot-assisted partial nephrectomy: a comparison of posterior and anterior renal masses.
abstract: OBJECTIVE
  Robot-assisted partial nephrectomy (RAPN) for posterior renal masses necessitates access to the posterior surface of the kidney either via a transperitoneal (TP) or retroperitoneal (RP) approach. While advocates of an RP approach claim reduced morbidity for posterior tumors, it is a less familiar approach to many urologists. In our institution, a TP approach is used for all patients undergoing RAPN. We compared demographics and perioperative outcomes of TP RAPN for posterior and anterior/lateral renal masses.
  
  
  METHODS
  Our institutional renal mass database was queried for patients with available preoperative imaging who underwent TP RAPN from 2007 to 2013. Posterior masses were accessed by opening the Gerota fascia and rotating the kidney anteromedially. Demographic and perioperative outcomes were compared for patients with posterior masses and anterior/lateral masses.
  
  
  RESULTS
  Overall, 260 TP RAPN were identified. Of these, 92 were for posterior tumors and 168 were for anterior and lateral tumors. Renal-cell carcinoma (RCC) was found in 77.3% of cases. Patient demographic and tumor characteristics were similar between groups. Among operative characteristics, warm ischemia time (17 vs 16.5, min P=0.70), operative time (160 vs 159 min, P=0.82), estimated blood loss (100 vs 100 mL, P=0.44), RCC positive surgical margins (1.4% vs 1.5%), and postoperative complications (19.6% vs 16.1%, P=1.0) were similar for posterior and anterior/lateral tumors, respectively.
  
  
  CONCLUSIONS
  TP RAPN is a safe, effective treatment option for patients with posterior renal masses with no additional morbidity compared with anterior/lateral renal masses. RP PN remains an alternative treatment option.
authors.affiliation: The James Buchanan Brady Urological Institute and Department of Urology, The Johns Hopkins School of Medicine , Baltimore, Maryland.
authors.forename: Kelly T
authors.initials: KT
authors.lastname: Harris
authors.forename: Mark W
authors.initials: MW
authors.lastname: Ball
authors.forename: Michael A
authors.initials: MA
authors.lastname: Gorin
authors.forename: Kevin M
authors.initials: KM
authors.lastname: Curtiss
authors.forename: Phillip M
authors.initials: PM
authors.lastname: Pierorazio
authors.forename: Mohamad E
authors.initials: ME
authors.lastname: Allaf
mesh_terms: D000368:Aged; D002292:Carcinoma, Renal Cell / Q000473:pathology / Q000601:surgery*; D005260:Female; D006801:Humans; D007668:Kidney / Q000601:surgery; D007680:Kidney Neoplasms / Q000473:pathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009392:Nephrectomy / Q000379:methods*; D061646:Operative Time; D056888:Patient Positioning; D011183:Postoperative Complications / Q000209:etiology; D012371:Robotics / Q000379:methods*; D016896:Treatment Outcome; D052096:Warm Ischemia