title: Laparoscopic partial nephrectomy for renal masses: effect of tumor location.
abstract: OBJECTIVE
  To report our single institutional experience of laparoscopic partial nephrectomy (LPN) for enhancing renal masses and evaluate outcomes and histopathologic findings with respect to the location of the renal mass.
  
  
  METHODS
  A retrospective review of LPN for 123 renal masses completed by 7 urologists was performed. Of these lesions, 49 (40%) were exophytic, 19 (15.5%) endophytic, 47 (38%) mesophytic, and 8 (6.5%) were hilar. We defined exophytic as more than 60%, mesophytic as 40% to 60%, and endophytic as less than 40% of the renal mass protruding off the surface of the kidney on radiologic imaging studies. Hilar lesions were those located within 5 mm of the renal hilar structures, regardless of the surface characteristics.
  
  
  RESULTS
  The mean tumor size was 2.6 cm (range 1 to 9). Hilar vessel clamping was performed during 55 procedures (44.7%); the mean warm ischemia time was 27 minutes (range 12 to 52). On final histopathologic examination, 3 patients (2.5%) had positive tumor resection margins. Overall, 26 (20.6%) complications occurred. The complication rate was significantly less for patients who underwent LPN for an exophytic (10%) or a mesophytic (12.8%) mass than for those with an endophytic (47%) or a hilar (50%) mass. Histopathologic examination of the renal masses revealed malignant pathologic features in 86 (69%) and benign findings in 37 (31%). In our series, only 55% of exophytic tumors were malignant and, if malignant, were invariably low grade (96%).
  
  
  CONCLUSIONS
  The complications of LPN and the malignancy rate of the renal lesions were related to the tumor location within the kidney.
authors.affiliation: Division of Urology, Department of Surgery, Washington University School of Medicine, St. Louis, Missouri 63110, USA. venkateshr@wudosis.wustl.edu
authors.forename: Ramakrishna
authors.initials: R
authors.lastname: Venkatesh
authors.forename: Kyle
authors.initials: K
authors.lastname: Weld
authors.forename: Caroline D
authors.initials: CD
authors.lastname: Ames
authors.forename: Sherbourne R
authors.initials: SR
authors.lastname: Figenshau
authors.forename: Chandru P
authors.initials: CP
authors.lastname: Sundaram
authors.forename: Gerald L
authors.initials: GL
authors.lastname: Andriole
authors.forename: Ralph V
authors.initials: RV
authors.lastname: Clayman
authors.forename: Jaime
authors.initials: J
authors.lastname: Landman
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D007680:Kidney Neoplasms / Q000473:pathology* / Q000601:surgery*; D010535:Laparoscopy; D008297:Male; D008875:Middle Aged; D009392:Nephrectomy / Q000379:methods*; D012189:Retrospective Studies