title: Factors affecting the outcome of extraperitoneal laparoscopic radical prostatectomy: pelvic arch interference and depth of the pelvic cavity.
abstract: OBJECTIVE
  To determine the effect of pelvic arch interference and the depth of the pelvic cavity, as shown on preoperative magnetic resonance imaging (MRI), on the performance of extraperitoneal laparoscopic radical prostatectomy (ELRP).
  
  
  METHODS
  In 115 patients, pelvic bone images were obtained at the time of prostate MRI before ELRP. In the reconstructed sagittal plane, we measured the true conjugate diameter, the obstetric conjugate diameter, the difference between the true and obstetric diameters, and the distance between the true conjugate and the prostate apex (pelvic depth). We analyzed which factors were associated with operative time (OT), estimated blood loss (EBL), and positive surgical margins (PSMs).
  
  
  RESULTS
  The difference between the true and obstetric conjugate diameters was 12.7±3.7 mm, and the pelvic depth was 59.9±6.0 mm. The OT, EBL, and the rate of PSMs were 260.1±91.1 minutes, 633.3±524.7 ml, and 19% (22/115), respectively. According to multiple linear regression analysis, predictors of a higher EBL included pelvic depth (3.0% higher per 1 mm increase in diameter difference, p=0.01) and prostate volume (1.5% higher per 1 cc increase in prostate volume, p=0.002). Factors associated with a longer OT were pelvic depth (p=0.04), serum prostate-specific antigen (p=0.04), prostate volume (p=0.02), and Gleason score (p=0.001). For PSMs, only pT2 was an independent factor.
  
  
  CONCLUSIONS
  Our results suggest that the depth of the pelvic cavity and prostate volume may increase surgical difficulty in patients undergoing ELRP.
authors.affiliation: Department of Urology, Chonnam National University Medical School, Gwangju, Korea.
authors.forename: Deok-Hyun
authors.initials: DH
authors.lastname: Nam
authors.forename: Eu Chang
authors.initials: EC
authors.lastname: Hwang
authors.forename: Chang Min
authors.initials: CM
authors.lastname: Im
authors.forename: Sun-Ouck
authors.initials: SO
authors.lastname: Kim
authors.forename: Seung Il
authors.initials: SI
authors.lastname: Jung
authors.forename: Dong Deuk
authors.initials: DD
authors.lastname: Kwon
authors.forename: Kwangsung
authors.initials: K
authors.lastname: Park
authors.forename: Soo Bang
authors.initials: SB
authors.lastname: Ryu