Hypothermia is known to limit the extent of myocardial infarction. The earlier hypothermia is applied to an ischemic myocardium, the more tissue can be salvaged. Topical negative pressure (TNP) is known to increase blood flow and stimulate angiogenesis in subcutaneous tissue and skeletal muscle. We have previously shown that a myocardial TNP of −50 mm Hg significantly increases microvascular blood flow in the underlying myocardium in ischemic and reperfused porcine myocardium. The present study was designed to elucidate the effect of different TNP levels on microvascular blood flow in reperfused myocardium during hypothermia.
Methods
Seven pigs underwent median sternotomy. The microvascular blood flow in the myocardium was recorded before and after the application of −50, −75, −100, −125, and −150 mm Hg using laser Doppler velocimetry. Analysis was performed in the epicardium and at a depth of 6 to 8 mm in the myocardium after 40 minutes of occlusion of the left anterior descending artery followed by cooling to 31°C, and reperfusion for another 20 minutes.
Results
A TNP of −50 mm Hg significantly increased blood the flow in the epicardium, from 116.7 ± 10.0 PU to 244.5 ± 52.6 PU (*P < 0.05) at 31°C. A TNP of −50 mm Hg significantly increased microvascular blood flow in the myocardium, from 155.0 ± 8.4 PU to 236.7 ± 61.5 PU (*P < 0.05).
Conclusions
Only a TNP of −50 mm Hg, applied over the left anterior descending artery region in reperfused hypothermic myocardium significantly increased the microvascular blood flow in the epicardium and in the myocardium.
MorykwasM.J., ArgentaL.C., Shelton-BrownE.I.Vacuum-assisted closure: a new method for wound control and treatment: animal studies and basic foundation. Ann Plast Surg.1997; 38: 553–562.
2.
ArgentaL.C., MorykwasM.J.Vacuum-assisted closure: a new method for wound control and treatment: clinical experience. Ann Plast Surg.1997; 38: 563–576; discussion 577.
3.
DomkowskiP.W., SmithM.L., GonyonD.L.Jr.Evaluation of vacuum-assisted closure in the treatment of poststernotomy mediastinitis. J Thorac Cardiovasc Surg.2003; 126: 386–390.
4.
GustafssonR.I., SjogrenJ., IngemanssonR.Deep sternal wound infection: a sternal-sparing technique with vacuum-assisted closure therapy. Ann Thorac Surg.2003; 76: 2048–2053; discussion 2053.
5.
SjogrenJ., GustafssonR., NilssonJ.Clinical outcome after poststernotomy mediastinitis: vacuum-assisted closure versus conventional treatment. Ann Thorac Surg.2005; 79: 2049–2055.
6.
GustafssonR., JohnssonP., AlgotssonL.Vacuum-assisted closure therapy guided by C-reactive protein level in patients with deep sternal wound infection. J Thorac Cardiovasc Surg.2002; 123: 895–900.
7.
ChenS.Z., LiJ., LiX.Y.Effects of vacuum-assisted closure on wound microcirculation: an experimental study. Asian J Surg.2005; 28: 211–217.
8.
WackenforsA., SjogrenJ., GustafssonR.Effects of vacuum-assisted closure therapy on inguinal wound edge microvascular blood flow. Wound Repair Regen.2004; 12: 600–606.
9.
VandenburghH.H.Mechanical forces and their second messengers in stimulating cell growth in vitro. Am J Physiol.1992; 262: R350–R355.
10.
SaxenaV., HwangC.W., HuangS.Vacuum-assisted closure: microdeformations of wounds and cell proliferation. Plast Reconstr Surg.2004; 114: 1086–1096; discussion 1097–1088.
11.
GreeneA.K., PuderM., RoyR.Microdeformational wound therapy: effects on angiogenesis and matrix metalloproteinases in chronic wounds of 3 debilitated patients. Ann Plast Surg.2006; 56: 418–422.
12.
LuJ.C., GraysonA.D., JhaP.Risk factors for sternal wound infection and mid-term survival following coronary artery bypass surgery. Eur J Cardiothorac Surg.2003; 23: 943–949.
13.
LoopF.D., LytleB.W., CosgroveD.M.J. Maxwell Chamberlain memorial paper. Sternal wound complications after isolated coronary artery bypass grafting: early and late mortality, morbidity, and cost of care. Ann Thorac Surg.1990; 49: 179–186; discussion 186–177.
14.
MilanoC.A., KeslerK., ArchibaldN.Mediastinitis after coronary artery bypass graft surgery. Risk factors and long-term survival. Circulation.1995; 92: 2245–2251.
15.
BraxtonJ.H., MarrinC.A., McGrathP.D.Mediastinitis and long-term survival after coronary artery bypass graft surgery. Ann Thorac Surg.2000; 70: 2004–2007.
16.
ToumpoulisI.K., AnagnostopoulosC.E., DeroseJ.J.Jr.The impact of deep sternal wound infection on long-term survival after coronary artery bypass grafting. Chest.2005; 127: 464–471.
SjogrenJ., NilssonJ., GustafssonR.The impact of vacuum-assisted closure on long-term survival after post-sternotomy mediastinitis. Ann Thorac Surg.2005; 80: 1270–1275.
19.
LindstedtS., MalmsjoM., IngemanssonR.Blood flow changes in normal and ischemic myocardium during topically applied negative pressure. Ann Thorac Surg.2007; 84: 568–573.
BernardS.New indications for the use of therapeutic hypothermia. Crit Care.2004; 8: E1.
22.
BernardS.Hypothermia after cardiac arrest: how to cool and for how long?Crit Care Med.2004; 32: 897–899.
23.
BernardS.A.Therapeutic hypothermia after cardiac arrest. Hypothermia is now standard care for some types of cardiac arrest. Med J Aust.2004; 181: 468–469.
24.
ZografosG.C., MartisK., MorrisD.L.Laser Doppler flowmetry in evaluation of cutaneous wound blood flow using various suturing techniques. Ann Surg.1992; 215: 266–268.
25.
SjogrenJ., GustafssonR., DobreM.Vacuum-assisted closure therapy in mediastinitis after heart transplantation. J Heart Lung Transplant.2004; 23: 506–507.
26.
WackenforsA., GustafssonR., SjogrenJ.Blood flow responses in the peristernal thoracic wall during vacuum-assisted closure therapy. Ann Thorac Surg.2005; 79: 1724–1730; discussion 1730–1721.
27.
LindstedtS., MalmsjoM., SjogrenJ.Impact of different topical negative pressure levels on myocardial microvascular blood flow. Cardiovasc Revasc Med. In press.
28.
BrazierJ.R., CooperN., McConnellD.H.Studies of the effects of hypothermia on regional myocardial blood flow and metabolism during cardiopulmonary bypass. III. Effects of temperature, time, and perfusion pressure in fibrillating hearts. J Thorac Cardiovasc Surg.1977; 73: 102–109.
29.
AhnH.C., EkrothR., HedenmarkJ.Assessment of myocardial perfusion in the empty beating porcine heart with laser Doppler flowmetry. Cardiovasc Res.1988; 22: 719–725.
30.
BuckbergG.D., BrazierJ.R., NelsonR.L.Studies of the effects of hypothermia on regional myocardial blood flow and metabolism during cardiopulmonary bypass. I. The adequately perfused beating, fibrillating, and arrested heart. J Thorac Cardiovasc Surg.1977; 73: 87–94.
31.
HottenrottC., BuckbergG.D., MaloneyJ.V.Jr.Effects of ventricular fibrillation on distribution and adequacy of coronary blood flow. Surg Forum.1972; 23: 200–202.
32.
BuckbergG.D., HottenrottC.E.Ventricular fibrillation. Its effect on myocardial flow, distribution, and performance. Ann Thorac Surg.1975; 20: 76–85.
33.
von AhnH.C., EkrothR., NilssonG.E.Assessment of myocardial perfusion with laser Doppler flowmetry. An experimental study on porcine heart. Scand J Thorac Cardiovasc Surg.1988; 22: 145–148.
34.
KangS., YangY.Coronary microvascular reperfusion injury and no-reflow in acute myocardial infarction. Clin Invest Med.2007; 30: E133–E145.
35.
van GaalW.J., BanningA.P.Percutaneous coronary intervention and the no-reflow phenomenon. Expert Rev Cardiovasc Ther.2007; 5: 715–731.
36.
ChenK.D., LiY.S., KimM.Mechanotransduction in response to shear stress. Roles of receptor tyrosine kinases, integrins, and Shc. J Biol Chem.1999; 274: 18393–18400.
37.
DetmarM., BrownL.F., BerseB.Hypoxia regulates the expression of vascular permeability factor/vascular endothelial growth factor (VPF/VEGF) and its receptors in human skin. J Invest Dermatol.1997; 108: 263–268.
38.
ShyuK.G., ChangM.L., WangB.W.Cyclical mechanical stretching increases the expression of vascular endothelial growth factor in rat vascular smooth muscle cells. J Formos Med Assoc.2001; 100: 741–747.
39.
MilkiewiczM., MohammadzadehF., IspanovicE.Static strain stimulates expression of matrix metalloproteinase-2 and VEGF in microvascular endothelium via JNK- and ERK-dependent pathways. J Cell Biochem.2007; 100: 750–761.
40.
SekoY., SekoY., TakahashiN.Pulsatile stretch stimulates vascular endothelial growth factor (VEGF) secretion by cultured rat cardiac myocytes. Biochem Biophys Res Commun.1999; 254: 462–465.
41.
RosengartT.K., LeeL.Y., PatelS.R.Six-month assessment of a phase I trial of angiogenic gene therapy for the treatment of coronary artery disease using direct intramyocardial administration of an adenovirus vector expressing the VEGF121 cDNA. Ann Surg.1999; 230: 466–470; discussion 470–462.
42.
RosengartT.K., LeeL.Y., PatelS.R.Angiogenesis gene therapy: phase I assessment of direct intramyocardial administration of an adenovirus vector expressing VEGF121 cDNA to individuals with clinically significant severe coronary artery disease. Circulation.1999; 100: 468–474.
