title: Anatomic renal artery branch microdissection to facilitate zero-ischemia partial nephrectomy.
abstract: BACKGROUND
  Robot-assisted and laparoscopic partial nephrectomies (PNs) for medial tumors are technically challenging even with the hilum clamped and, until now, were impossible to perform with the hilum unclamped.
  
  
  OBJECTIVE
  Evaluate whether targeted vascular microdissection (VMD) of renal artery branches allows zero-ischemia PN to be performed even for challenging medial tumors.
  
  
  METHODS
  A prospective cohort evaluation of 44 patients with renal masses who underwent robot-assisted or laparoscopic zero-ischemia PN either with anatomic VMD (group 1; n=22) or without anatomic VMD (group 2; n=22) performed by a single surgeon from April 2010 to January 2011.
  
  
  METHODS
  Zero-ischemia PN with VMD incorporates four maneuvers: (1) preoperative computed tomographic reconstruction of renal arterial branch anatomy, (2) anatomic dissection of targeted, tumor-specific tertiary or higher-order renal arterial branches, (3) neurosurgical aneurysm microsurgical bulldog clamp(s) for superselective tumor devascularization, and (4) transient, controlled reduction of blood pressure, if necessary.
  
  
  METHODS
  Baseline, perioperative, and postoperative data were collected prospectively.
  
  
  CONCLUSIONS
  Group 1 tumors were larger (4.3 vs 2.6 cm; p=0.011), were more often hilar (41% vs 9%; p=0.09), were medial (59% and 23%; p=0.017), were closer to the hilum (1.46 vs 3.26 cm; p=0.0002), and had a lower C index score (2.1 vs 3.9; p=0.004) and higher RENAL nephrometry scores (7.7 vs 6.2; p=0.013). Despite greater complexity, no group 1 tumor required hilar clamping, and perioperative outcomes were similar to those of group 2: operating room time (4.7 and 4.1h), median blood loss (200 and 100ml), surgical margins for cancer (all negative), major complications (0% and 9%), and minor complications (18% and 14%). The median serum creatinine level was similar 2 mo postoperatively (1.2 and 1.3mg/dl). The study was limited by the relatively small sample size.
  
  
  CONCLUSIONS
  Anatomic targeted dissection and superselective control of tumor-specific renal arterial branches facilitate zero-ischemia PN. Even challenging medial and hilar tumors can be excised without hilar clamping. Global surgical renal ischemia has been eliminated for most patients undergoing PN at our institution.
authors: USC Institute of Urology, Center for Advanced Robotic and Laparoscopic Surgery, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.
authors: Casey K
authors: CK
authors: Ng
authors: Inderbir S
authors: IS
authors: Gill
authors: Mukul B
authors: MB
authors: Patil
authors: Andrew J
authors: AJ
authors: Hung
authors: Andre K
authors: AK
authors: Berger
authors: Andre Luis
authors: AL
authors: de Castro Abreu
authors: Masahiko
authors: M
authors: Nakamoto
authors: Manuel S
authors: MS
authors: Eisenberg
authors: Osamu
authors: O
authors: Ukimura
authors: Duraiyah
authors: D
authors: Thangathurai
authors: Monish
authors: M
authors: Aron
authors: Mihir M
authors: MM
authors: Desai
mesh_terms: D000328:Adult; D000368:Aged; D016063:Blood Loss, Surgical; D005260:Female; D006801:Humans; D007680:Kidney Neoplasms / Q000098:blood supply / Q000175:diagnosis / Q000473:pathology / Q000601:surgery*; D010535:Laparoscopy / Q000009:adverse effects; D007902:Length of Stay; D015141:Los Angeles; D008297:Male; D042282:Microdissection / Q000009:adverse effects; D008875:Middle Aged; D009392:Nephrectomy / Q000009:adverse effects / Q000379:methods*; D059351:Organ Sparing Treatments / Q000009:adverse effects; D011183:Postoperative Complications / Q000209:etiology; D011446:Prospective Studies; D012077:Renal Artery / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D012079:Renal Circulation; D012371:Robotics; D025321:Surgery, Computer-Assisted / Q000009:adverse effects; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D018615:Ultrasonography, Doppler, Color