title: Renal oxygenation during robot-assisted laparoscopic partial nephrectomy: characterization using laparoscopic digital light processing hyperspectral imaging.
abstract: Abstract Background and Purpose: Digital light processing-based hyperspectral imaging (DLP(®)-HSI) was adapted for use during laparoscopic surgery by coupling the spectral illumination source with a conventional laparoscopic light guide and incorporating a customized digital charge-coupled device camera for image acquisition. The system was used to characterize renal oxygenation during robot-assisted laparoscopic partial nephrectomy (RALPN) in humans.
  
  
  METHODS
  After Institutional Review Board approval, laparoscopic DLP-HSI was performed in consecutive patients undergoing RALPN at our institution. Time trends in relative tissue oxygen saturation (%HbO2) were descriptively analyzed. Associations between %HbO2 and patient age, comorbidities, and estimated glomerular filtration rate (eGFR) were investigated using the Kendall tau test.
  
  
  RESULTS
  Laparoscopic DLP-HSI was performed in 18 patients between May 2011 and February 2012. Median (interquartile range; IQR) age was 55.9 (49-67.5) years. Of the patients, 10/18 (56%) were men and 12/18 (66.7%) had a history of hypertension, diabetes, and/or tobacco use. Median (IQR) %HbO2 before, during, and after ischemia was 60.8% (57.9-68.2%), 53.6% (46.8-55.1%), and 61.5% (54.9-67.6%), respectively. Baseline %HbO2 was inversely associated with preoperative eGFR (τ=-0.38; P=0.036), and eGFR at most recent follow-up (τ=-0.38; P=0.036). Baseline or ischemic %HbO2 did not correlate with hypertension, diabetes, and/or tobacco history. Younger patients (<56 years) had a lower median baseline %HbO2 (P=0.07) and a higher median preoperative eGFR (P=0.038), than their older counterparts.
  
  
  CONCLUSIONS
  The laparoscopic HSI system successfully characterized dynamic changes in renal oxygenation during RALPN. Intraoperative laparoscopic HSI outcomes have the potential to predict postoperative individual kidney function.
authors.affiliation: Department of Urology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
authors.forename: Ephrem O
authors.initials: EO
authors.lastname: Olweny
authors.forename: Stephen
authors.initials: S
authors.lastname: Faddegon
authors.forename: Sara L
authors.initials: SL
authors.lastname: Best
authors.forename: Neil
authors.initials: N
authors.lastname: Jackson
authors.forename: Eleanor F
authors.initials: EF
authors.lastname: Wehner
authors.forename: Yung K
authors.initials: YK
authors.lastname: Tan
authors.forename: Karel J
authors.initials: KJ
authors.lastname: Zuzak
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Cadeddu
mesh_terms: D000368:Aged; D003952:Diagnostic Imaging / Q000295:instrumentation*; D005260:Female; D006801:Humans; D007668:Kidney / Q000473:pathology*; D010535:Laparoscopy; D008027:Light; D008297:Male; D008875:Middle Aged; D009392:Nephrectomy / Q000295:instrumentation*; D010100:Oxygen / Q000378:metabolism*; D010108:Oxyhemoglobins / Q000378:metabolism; D012371:Robotics; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D010108:Oxyhemoglobins; D010100:Oxygen