Hemodynamic analysis of descending versus ascending aortomyoplasty, and comparison with intra-aortic balloon pump.
OBJECTIVE
Descending and ascending aortomyoplasty are two surgical procedures intended to induce hemodynamic benefits similar to those of the intra-aortic-balloon-pump (IABP). To date, there have been no studies comparing the two surgical techniques. The objective of this study was to compare coronary blood flow augmentation and afterload reduction as produced by descending and ascending aortomyoplasty counterpulsation


METHODS
Twenty-two mongrel dogs (18-35 kg) underwent IABP application (n=7), descending (n=8), or ascending (n=7) aortomyoplasty. Left anterior descending (LAD) coronary artery blood flow was measured using a Transonic Doppler flow probe. Left ventricular pressure as well as aortic pressures proximal and distal to either the aortomyoplasty site or the IABP position were monitored continuously.


RESULTS
Descending aortomyoplasty induced higher elevation in the LAD blood flow during assisted beats (27% from 10.8+/-4 to 13.8+/-6 ml/min, P<0.001) than that induced by either ascending aortomyoplasty (19% from 11.7+/-5 to 14+/-5 ml/min, P<0.001) or IABP counterpulsation (18% from 8.6+/-3 to 10.2+/-4 ml/min, P<0.001). Conversely, while ascending aortomyoplasty reduced the left ventricular end-diastolic pressure by 16% (from 60+/-18 to 50+/-22 mmHg, P<0.001), similar to the 16% after load reduction achieved by the IABP counterpulsation, descending aortomyoplasty failed to induce afterload reduction.


CONCLUSIONS
Descending aortomyoplasty produces higher coronary blood flow augmentation than either ascending aortomyoplasty or IABP. However, afterload reduction comparable to that achieved by IABP was observed only with ascending aortomyoplasty and not with descending aortomyoplasty.
Bolotin
Gil
G
The Department of Cardiothoracic Surgery, Tel Aviv Sourasky Medical Center, 6 Weizman Street, Israel. bolotin@netvision.net.il
van der Veen
Frederik H
FH
Lorusso
Roberto
R
Wolf
Tamir
T
Sachner
Robert
R
Shofti
Rona
R
Shreuder
Jan J
JJ
Uretzky
Gideon
G
D000818:Animals; D001011:Aorta / Q000601:surgery*; D001794:Blood Pressure; D003326:Coronary Circulation; D004285:Dogs; D004558:Electric Stimulation; D007423:Intra-Aortic Balloon Pumping; D018482:Muscle, Skeletal / Q000637:transplantation*