title: Intraoperative colon mucosal oxygen saturation during aortic surgery.
abstract: BACKGROUND
  Colonic ischemia after aortic reconstruction is a devastating complication with high mortality rates. This study evaluates whether Colon Mucosal Oxygen Saturation (CMOS) correlates with colon ischemia during aortic surgery.
  
  
  METHODS
  Aortic reconstruction was performed in 25 patients, using a spectrophotometer probe that was inserted in each patient's rectum before the surgical procedure. Continuous CMOS, buccal mucosal oxygen saturation, systemic mean arterial pressure, heart rate, pulse oximetry, and pivotal intra-operative events were collected.
  
  
  RESULTS
  Endovascular aneurysm repair (EVAR) was performed in 20 and open repair in 5 patients with a mean age of 75 +/- 10 (+/-SE) years. CMOS reliably decreased in EVAR from a baseline of 56% +/- 8% to 26 +/- 17% (P < 0.0001) during infrarenal aortic balloon occlusion and femoral arterial sheath placement. CMOS similarly decreased during open repair from 56% +/- 9% to 15 +/- 19% (P < 0.0001) when the infrarenal aorta and iliac arteries were clamped. When aortic circulation was restored in both EVAR and open surgery, CMOS returned to baseline values 56.5 +/- 10% (P = 0.81). Mean recovery time in CMOS after an aortic intervention was 6.4 +/- 3.3 min. Simultaneous buccal mucosal oxygen saturation was stable (82% +/- 6%) during aortic manipulation but would fall significantly during active bleeding. There were no device related CMOS measurement complications.
  
  
  CONCLUSIONS
  Intra-operative CMOS is a sensitive measure of colon ischemia where intraoperative events correlated well with changes in mucosal oxygen saturation. Transient changes demonstrate no problem. However, persistently low CMOS suggests colon ischemia, thus providing an opportunity to revascularize the inferior mesenteric artery or hypogastric arteries to prevent colon infarction.
authors.affiliation: Department of Surgery, University of California, Davis, California 95817, USA. EugeneS.Lee@ucdmc.davis.edu
authors.forename: Eugene S
authors.initials: ES
authors.lastname: Lee
authors.forename: Arie
authors.initials: A
authors.lastname: Bass
authors.forename: Frank R
authors.initials: FR
authors.lastname: Arko
authors.forename: Maarit
authors.initials: M
authors.lastname: Heikkinen
authors.forename: E John
authors.initials: EJ
authors.lastname: Harris
authors.forename: Christopher K
authors.initials: CK
authors.lastname: Zarins
authors.forename: Pieter
authors.initials: P
authors.lastname: van der Starre
authors.forename: Cornelius
authors.initials: C
authors.lastname: Olcott
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D017544:Aortic Aneurysm, Abdominal / Q000601:surgery*; D001794:Blood Pressure; D003106:Colon / Q000098:blood supply* / Q000378:metabolism; D005260:Female; D006339:Heart Rate; D006801:Humans; D007083:Iliac Artery; D007413:Intestinal Mucosa / Q000098:blood supply / Q000378:metabolism; D007431:Intraoperative Complications / Q000517:prevention & control*; D007511:Ischemia / Q000378:metabolism / Q000517:prevention & control*; D008027:Light; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000295:instrumentation / Q000379:methods*; D010092:Oximetry; D010100:Oxygen / Q000378:metabolism*; D011446:Prospective Studies; D019651:Plastic Surgery Procedures; D012007:Rectum; D012077:Renal Artery; D013057:Spectrum Analysis / Q000295:instrumentation / Q000379:methods; D014656:Vascular Surgical Procedures
chemical_list: D010100:Oxygen