title: Extra-aortic balloon counterpulsation: an intraoperative feasibility study.
abstract: BACKGROUND
  Current methods of counterpulsation or ventricular assistance have significant vascular and limb complications. The aim of this study was to determine the safety and performance of a new method of non-blood-contacting counterpulsation using an inflatable cuff around the ascending aorta (extra-aortic balloon [EAB]).
  
  
  RESULTS
  In 6 patients undergoing first time off-pump coronary bypass surgery via sternotomy, the EAB was secured around the ascending aorta and attached to a standard counterpulsation console. At baseline and with 1:2 and 1:1 augmentation, hemodynamic and echocardiographic parameters of ventricular function and coronary flow were measured. High-intensity transient signals were measured using transcutaneous Doppler over the right common carotid artery. No complications occurred. With EAB there was no significant change in heart rate or blood pressure and no increase in high-intensity transient signals. There was a 67% increase in diastolic coronary blood flow (mean left-main diastolic velocity time integral 15.3 cm unassisted versus 25.1 cm assisted, P<0.05). Measurements with transesophageal echocardiography at baseline and with 1:1 counterpulsation demonstrated a 6% reduction in end-diastolic area (P=NS), a 16% reduction in end-systolic area (P<0.01), a 31% reduction in left ventricular wall stress (P<0.05), and a 13% improvement in fractional area change (P<0.005).
  
  
  CONCLUSIONS
  EAB counterpulsation augments coronary flow and reduces left ventricular afterload. Further testing is warranted to assess the use of the EAB for chronic non-blood-contacting support of the failing heart.
authors.affiliation: Department of Cardiology, Green Lane Hospital, Auckland, New Zealand. malcolml@adhb.govt.nz
authors.forename: Malcolm E
authors.initials: ME
authors.lastname: Legget
authors.forename: William S
authors.initials: WS
authors.lastname: Peters
authors.forename: F Paget
authors.initials: FP
authors.lastname: Milsom
authors.forename: Judith S
authors.initials: JS
authors.lastname: Clark
authors.forename: Teena M
authors.initials: TM
authors.lastname: West
authors.forename: Renelle L
authors.initials: RL
authors.lastname: French
authors.forename: Alan F
authors.initials: AF
authors.lastname: Merry
mesh_terms: D000328:Adult; D000368:Aged; D001011:Aorta; D017536:Carotid Artery, Common / Q000000981:diagnostic imaging; D047549:Coronary Artery Bypass, Off-Pump / Q000379:methods; D003326:Coronary Circulation; D023921:Coronary Stenosis / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D015908:Counterpulsation / Q000295:instrumentation / Q000379:methods*; D018619:Echocardiography, Doppler, Pulsed; D017548:Echocardiography, Transesophageal; D004867:Equipment Design; D005240:Feasibility Studies; D005260:Female; D006333:Heart Failure / Q000601:surgery*; D006439:Hemodynamics; D006801:Humans; D007430:Intraoperative Care / Q000379:methods*; D008297:Male; D008875:Middle Aged; D013318:Stroke Volume