title: Non-invasive monitoring of tissue oxygenation during laparoscopic donor nephrectomy.
abstract: BACKGROUND
  Standard methods for assessment of organ viability during surgery are typically limited to visual cues and tactile feedback in open surgery. However, during laparoscopic surgery, these processes are impaired. This is of particular relevance during laparoscopic renal donation, where the condition of the kidney must be optimized despite considerable manipulation. However, there is no in vivo methodology to monitor renal parenchymal oxygenation during laparoscopic surgery.
  
  
  METHODS
  We have developed a method for the real time, in vivo, whole organ assessment of tissue oxygenation during laparoscopic nephrectomy to convey meaningful biological data to the surgeon during laparoscopic surgery. We apply the 3-CCD (charge coupled device) camera to monitor qualitatively renal parenchymal oxygenation with potential real-time video capability.
  
  
  RESULTS
  We have validated this methodology in a porcine model across a range of hypoxic conditions, and have then applied the method during clinical laparoscopic donor nephrectomies during clinically relevant pneumoperitoneum. 3-CCD image enhancement produces mean region of interest (ROI) intensity values that can be directly correlated with blood oxygen saturation measurements (R2 > 0.96). The calculated mean ROI intensity values obtained at the beginning of the laparoscopic nephrectomy do not differ significantly from mean ROI intensity values calculated immediately before kidney removal (p > 0.05).
  
  
  CONCLUSIONS
  Here, using the 3-CCD camera, we qualitatively monitor tissue oxygenation. This means of assessing intraoperative tissue oxygenation may be a useful method to avoid unintended ischemic injury during laparoscopic surgery. Preliminary results indicate that no significant changes in renal oxygenation occur as a result of pneumoperitoneum.
authors.affiliation: Naval Medical Research Center, Combat Casualty Care, Silver Spring, MD 20910, USA. Nicole.Crane@med.navy.mil
authors.forename: Nicole J
authors.initials: NJ
authors.lastname: Crane
authors.forename: Peter A
authors.initials: PA
authors.lastname: Pinto
authors.forename: Douglas
authors.initials: D
authors.lastname: Hale
authors.forename: Frederick A
authors.initials: FA
authors.lastname: Gage
authors.forename: Doug
authors.initials: D
authors.lastname: Tadaki
authors.forename: Allan D
authors.initials: AD
authors.lastname: Kirk
authors.forename: Ira W
authors.initials: IW
authors.lastname: Levin
authors.forename: Eric A
authors.initials: EA
authors.lastname: Elster
mesh_terms: D000328:Adult; D000465:Algorithms; D000818:Animals; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D016030:Kidney Transplantation; D010535:Laparoscopy; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000379:methods*; D009392:Nephrectomy; D010101:Oxygen Consumption / Q000502:physiology*; D015203:Reproducibility of Results; D013057:Spectrum Analysis; D013552:Swine; D014022:Tissue Survival / Q000502:physiology; D020858:Tissue and Organ Harvesting