title: Changes in radial artery volume assessed using intravascular ultrasound: a comparison of two vasodilator regimens in transradial coronary interventions.
abstract: OBJECTIVE
  This study used intravascular ultrasound (IVUS) to evaluate radial artery volume changes after intraarterial administration of nitroglycerin and/or verapamil.
  
  
  BACKGROUND
  Radial artery spasm, which is associated with radial artery size, is the main limitation of the transradial approach in percutaneous coronary interventions (PCI).
  
  
  METHODS
  This prospective, randomized study compared the effect of two intra-arterial vasodilator regimens on radial artery volume: 0.2 mg of nitroglycerin plus 2.5 mg of verapamil (Group 1; n = 15) versus 2.5 mg of verapamil alone (Group 2; n = 15). Radial artery lumen volume was assessed using IVUS at two time points: at baseline (5 minutes after sheath insertion) and post-vasodilator (1 minute after drug administration). The luminal volume of the radial artery was computed using ECOC Random Fields (ECOC-RF), a technique used for automatic segmentation of luminal borders in longitudinal cut images from IVUS sequences.
  
  
  RESULTS
  There was a significant increase in arterial lumen volume in both groups, with an increase from 451 ± 177 mm³ to 508 ± 192 mm³ (p = 0.001) in Group 1 and from 456 ± 188 mm³ to 509 ± 170 mm³ (p = 0.001) in Group 2. There were no significant differences between the groups in terms of absolute volume increase (58 mm³ versus 53 mm³, respectively; p = 0.65) or in relative volume increase (14% versus 20%, respectively; p = 0.69).
  
  
  CONCLUSIONS
  Administration of nitroglycerin plus verapamil or verapamil alone to the radial artery resulted in similar increases in arterial lumen volume according to ECOC-RF IVUS measurements.
authors.affiliation: Cardiology Service, Hospital Universitari Germans Trias i Pujol, Barcelona.
authors.forename: Xavier
authors.initials: X
authors.lastname: Carrillo
authors.forename: Eduard
authors.initials: E
authors.lastname: Fernandez-Nofrerias
authors.forename: Francesco
authors.initials: F
authors.lastname: Ciompi
authors.forename: Oriol
authors.initials: O
authors.lastname: Rodriguez-Leor
authors.forename: Petia
authors.initials: P
authors.lastname: Radeva
authors.forename: Neus
authors.initials: N
authors.lastname: Salvatella
authors.forename: Oriol
authors.initials: O
authors.lastname: Pujol
authors.forename: Josepa
authors.initials: J
authors.lastname: Mauri
authors.forename: Antoni
authors.initials: A
authors.lastname: Bayes-Genis
mesh_terms: D000368:Aged; D004338:Drug Combinations; D005260:Female; D006801:Humans; D007269:Injections, Intra-Arterial; D008297:Male; D008875:Middle Aged; D005996:Nitroglycerin / Q000008:administration & dosage / Q000494:pharmacology; D011446:Prospective Studies; D017534:Radial Artery / Q000000981:diagnostic imaging* / Q000187:drug effects*; D018084:Ultrasonography, Interventional; D014665:Vasodilator Agents / Q000008:administration & dosage / Q000494:pharmacology*; D014700:Verapamil / Q000008:administration & dosage / Q000494:pharmacology
chemical_list: D004338:Drug Combinations; D014665:Vasodilator Agents; D014700:Verapamil; D005996:Nitroglycerin