Evaluation of continuous and intermittent myocardial topical negative pressure.
OBJECTIVE
Topical negative pressure, commonly used in wound therapy, has been shown to increase blood flow and stimulate angiogenesis in subcutaneous tissue and skeletal muscle. In wound therapy, intermittent negative pressure is often preferred to continuous negative pressure as tissue exposed to intermittent therapy shows twice as much granulation tissue formation than that exposed to continuous pressure after 2 weeks of therapy. The present study was designed to elucidate the differences in microvascular blood flow in the left anterior descending artery area between continuous and intermittent myocardial topical negative pressure of -50 mmHg.


METHODS
Six pigs underwent median sternotomy. Laser Doppler probes were inserted horizontally into the heart muscle in the left anterior descending artery area at depths of approximately 5-6 mm. Measurements of microvascular blood flow were performed in normal myocardium and ischemic myocardium during 20 min of countinuous and intermittent topical negative pressure at -50 mmHg.


RESULTS
Both continuous and intermittent topical negative pressure of -50 mmHg significantly increased microvascular blood flow in the underlying myocardium: from 56.2 +/- 13.1 perfusion units (PU) before to 132.8 +/- 7.4 PU during countinuous topical negative pressure application (P < 0.05) and from 75.8 +/- 12.1 PU before to 153.6 +/- 4.7 PU during intermittent topical negative pressure application (P < 0.05).


CONCLUSIONS
No statistically significant difference was found between microvascular blood flow during 20 min of continuous and intermittent topical negative pressure at -50 mmHg in this porcine model.
Lindstedt
Sandra
S
Department of Cardiothoracic Surgery, Sweden. sandra.lindstedt@skane.se
Malmsjö
Malin
M
Gesslein
Bodil
B
Ingemansson
Richard
R
D000818:Animals; D003097:Collateral Circulation / Q000502:physiology; D003326:Coronary Circulation / Q000502:physiology*; D003331:Coronary Vessels / Q000503:physiopathology*; D004195:Disease Models, Animal; D005260:Female; D017078:Laser-Doppler Flowmetry / Q000379:methods; D008297:Male; D008833:Microcirculation / Q000502:physiology; D015428:Myocardial Reperfusion Injury / Q000503:physiopathology / Q000628:therapy*; D054843:Negative-Pressure Wound Therapy / Q000379:methods*; D013552:Swine; D016896:Treatment Outcome