title: Comparison of extraperitoneal and transperitoneal pelvic lymph node dissection during minimally invasive radical prostatectomy.
abstract: OBJECTIVE
  Pelvic lymph node dissection (PLND) during radical prostatectomy (RP) has prognostic and possible therapeutic benefits. We assessed whether an extraperitoneal minimally invasive RP (MiRP) allows for standard-template PLND comparable to transperitoneal MiRP+PLND.
  
  
  METHODS
  A retrospective clinicopathologic study of 914 consecutive patients who underwent MiRP (laparoscopic or Da Vinci robot-assisted laparoscopic) with bilateral PLND by one surgeon (CPP) from 2001 to 2010 was performed. Low-risk patients generally received a limited dissection (external iliac nodes) when PLND was performed. Those with intermediate- and high-risk disease generally received a standard PLND (external iliac and obturator nodes). Patients were stratified into groups based on operative approach (extraperitoneal vs transperitoneal) for most analyses.
  
  
  RESULTS
  Overall, 192 patients had transperitoneal MiRP+PLND, and 377 had extraperitoneal MiRP+PLND. The extraperitoneal group had higher body mass index (P=0.03), a higher percentage of low-risk (P=0.003), and a lower percentage of intermediate-risk disease (P=0.006). Lymph node yield (LNY) was higher with extraperitoneal PLND overall (6.5 vs 5.3, P=0.003). When stratified by risk category, LNY was greater in the extraperitoneal group for patients with low-risk disease only (6.6 vs 4.9, P=0.008). There was no difference in nodal yield in intermediate/high-risk patients receiving standard PLND by either the transperitoneal or extraperitoneal approach (6.0 vs 5.5, P=0.36 and 8.0 vs 5.8, P=0.14, respectively). Lymph node involvement was rare overall. Estimated blood loss and complication rates were comparable between operative approaches.
  
  
  CONCLUSIONS
  The extraperitoneal MiRP approach does not compromise the oncologic efficacy or safety of routine PLND.
authors.affiliation: James Buchanan Brady Urological Institute, Johns Hopkins Medical Institutions, Baltimore, Maryland 21287, USA. jmulli12@jhmi.edu
authors.forename: Jeffrey K
authors.initials: JK
authors.lastname: Mullins
authors.forename: M Eric
authors.initials: ME
authors.lastname: Hyndman
authors.forename: Lynda Z
authors.initials: LZ
authors.lastname: Mettee
authors.forename: Christian P
authors.initials: CP
authors.lastname: Pavlovich
mesh_terms: D003710:Demography; D006801:Humans; D008197:Lymph Node Excision / Q000379:methods*; D008198:Lymph Nodes / Q000601:surgery; D008297:Male; D008875:Middle Aged; D019060:Minimally Invasive Surgical Procedures / Q000379:methods*; D010388:Pelvis / Q000601:surgery; D010537:Peritoneum / Q000601:surgery*; D011468:Prostatectomy / Q000379:methods*