title: Duplex ultrasonography predicts safety of radial artery harvest in the presence of an abnormal Allen test.
abstract: BACKGROUND
  The Allen test is commonly used to assess collateral hand circulation before radial artery harvest for coronary artery bypass grafting. However there is no consensus as to whether an abnormal Allen test is an absolute or relative contraindication to radial artery harvesting. We assessed the safety of harvesting the radial artery using arterial duplex ultrasonography in patients with an abnormal Allen test.
  
  
  METHODS
  Two hundred and eighty-seven consecutive patients scheduled for total arterial coronary revascularisation underwent preoperative Allen tests over a 34-month period. Patients with an abnormal Allen test underwent duplex ultrasonography preoperatively to assess the adequacy of the ulnar collateral supply and the suitability of the radial artery for harvesting.
  
  
  RESULTS
  Two hundred and forty-four patients (85%) had a normal left Allen test and proceeded directly to radial artery harvest. Forty-three patients (15%) with an abnormal left Allen test underwent duplex ultrasonography scans and of those, 5 patients had an abnormal scan. These patients underwent scanning of the contralateral forearm. Three patients had a normal right forearm arterial duplex scan and the right radial artery was harvested. The mean diameter of the radial and ulnar arteries was not significantly different between the patients with normal and abnormal duplex ultrasonograms. There were no ischemic hand complications in this series.
  
  
  CONCLUSIONS
  The Allen test is a quick, easy, and reliable screening test before radial artery harvesting in the majority of patients. Duplex ultrasonography predicts safe radial artery harvest in the majority of patients with an abnormal Allen test.
authors.affiliation: Department of Cardiothoracic Surgery John Radcliffe Hospital, Oxford, England, UK.
authors.forename: Yasir
authors.initials: Y
authors.lastname: Abu-Omar
authors.forename: Shafi
authors.initials: S
authors.lastname: Mussa
authors.forename: Kyriakos
authors.initials: K
authors.lastname: Anastasiadis
authors.forename: Sarah
authors.initials: S
authors.lastname: Steel
authors.forename: Linda
authors.initials: L
authors.lastname: Hands
authors.forename: David P
authors.initials: DP
authors.lastname: Taggart
mesh_terms: D000465:Algorithms; D003097:Collateral Circulation; D000075202:Contraindications; D006225:Hand / Q000098:blood supply; D006801:Humans; D011237:Predictive Value of Tests; D017534:Radial Artery / Q000002:abnormalities / Q000000981:diagnostic imaging* / Q000601:surgery*; D020858:Tissue and Organ Harvesting; D018616:Ultrasonography, Doppler, Duplex