title: Descending aortic blood flow during aortic cross-clamp indicates postoperative splanchnic perfusion and gastrointestinal function in patients undergoing aortic reconstruction.
abstract: BACKGROUND
  The purpose of this observational study was to investigate the relationship between splanchnic and renal blood flow during infrarenal aortic cross-clamp (XC) and postoperative gastrointestinal perfusion and function.
  
  
  METHODS
  Descending aortic blood flow (DABF) was continuously monitored with an oesophageal Doppler monitor (Cardio-Q, Deltex Ltd, Chichester, UK) in 31 patients undergoing elective abdominal aortic aneurysm repair. Cardiac output (CO) was determined by indocyanine green dilution before, during, and after XC. Perioperative gastrointestinal perfusion was assessed by gastric intramucosal pH (pHi, Tonocap, GE Healthcare, Helsinki, Finland). Postoperative gastrointestinal recovery was assessed by the number of postoperative days until the patient successfully resumed solid food intake. The relationship between the mean DABF during XC and gastric pHi after XC release and postoperative gastrointestinal recovery was analysed with Spearman's correlation coefficient.
  
  
  RESULTS
  accounted for ∼ 55% of CO during XC and significantly decreased during XC, despite arterial pressure remaining within an optimal range. There were two distinct relationships between DABF during XC and gastric pHi after XC release. Gastric pHi steeply and linearly declined when indexed DABF was below 0.82 litre min(-1) m(-2). Above this critical value, there was no linear relationship between them. The duration of postoperative gastrointestinal dysfunction was inversely correlated with the mean DABF during XC. The best cut-off value of the mean indexed DABF during XC to prevent prolonged gastrointestinal dysfunction was 1.2 litre min(-1) m(-2).
  
  
  CONCLUSIONS
  Decreased DABF during XC associates splanchnic hypoperfusion after XC release and delayed recovery of gastrointestinal function.
authors.affiliation: Department of Anaesthesiology and Perioperative Care, Toho University Ohashi Medical Center, 2-17-6, Ohashi, Meguro, Tokyo 153-8515, Japan. ykotake@med.toho-u.ac.jp
authors.forename: Y
authors.initials: Y
authors.lastname: Kotake
authors.forename: T
authors.initials: T
authors.lastname: Yamada
authors.forename: H
authors.initials: H
authors.lastname: Nagata
authors.forename: J
authors.initials: J
authors.lastname: Takeda
authors.forename: H
authors.initials: H
authors.lastname: Shimizu
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001013:Aorta, Thoracic / Q000503:physiopathology*; D017544:Aortic Aneurysm, Abdominal / Q000503:physiopathology / Q000601:surgery*; D002302:Cardiac Output; D005260:Female; D005745:Gastric Acidity Determination; D041981:Gastrointestinal Tract / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011184:Postoperative Period; D012039:Regional Blood Flow; D013152:Splanchnic Circulation