A compare between myocardial topical negative pressure levels of -25 mmHg and -50 mmHg in a porcine model

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Topical negative pressure (TNP), widely used in wound therapy, is known to stimulate wound edge blood flow, granulation tissue formation, angiogenesis, and revascularization. We have previously shown that application of a TNP of -50 mmHg to the myocardium significantly increases microvascular blood flow in the underlying tissue. We have also shown that a myocardial TNP levels between -75 mmHg and -150 mmHg do not induce microvascular blood flow changes in the underlying myocardium. The present study was designed to elucidate the difference between- 25 mmHg and -50 mmHg TNP on microvascular flow in normal and ischemic myocardium.

Six pigs underwent median sternotomy. The microvascular blood flow in the myocardium was recorded before and after the application of TNP using laser Doppler flowmetry. Analyses were performed before left anterior descending artery (LAD) occlusion (normal myocardium), and after 20 minutes of AD occlusion (ischemic myocardium).

A TNP of -25 mmHg significantly increased microvascular blood flow in both normal (from 263.3 ± 62.8 U before, to 380.0 ± 80.6 PU after TNP application, * p = 0.03) and ischemic myocardium (from 58.8 ± 17.7 PU before, to 85.8 ± 20.9 PU after TNP application, * p = 0.04). TNP of -50 mmHg also significantly increased microvascular blood flow in both normal (from 174.2± 20.8 PU before, to 240.0 ± 34.4 PU after TNP application, * p = 0.02) and ischemic myocardium (from 44.5 ± 14.0 PU before, to 106.2 ± 26.6 PU after TNP application, ** p = 0.01).

Topical negative pressure of -25 mmHg and -50 mmHg both induced a significant increase in microvascular blood flow in normal and in ischemic myocardium. The increase in microvascular blood flow was larger when using -25 mmHg on normal myocardium, and was larger when using -50 mmHg on ischemic myocardium; however these differences were not statistically significant.


TNP produces a mechanical stress and a pressure gradient across the tissue which may cause a surge of blood to the area. Mechanical forces and increased blood flow are known to stimulate granulation tissue formation, i.e. endothelial proliferation, capillary budding and angiogenesis3,4. Poststernotomy mediastinitis is a strong predictor for poor long-term survival after coronary artery by-pass surgery (CABG), when using conventional wound healing techniques (closed irrigation, delayed wound closure, or reconstructing with momentum or pectoral flaps)5,6. Braxton and coworkers demonstrated that actuarial survival after 10 years was 39% in patients with oststernotomymediastinitis and 70% in patients without mediastinitis6. Milano and collages have suggested that mediastinitis may cause negative long-terms effects on several organs such as the heart and kidneys5. Lately, the usefulness of TNP in the treatment of poststernotomy mediastinitis has been well recognized among cardiothoracic surgeons around the world, due to excellent clinical outcome7,8.


  1. Chen SZ, Li J, Li XY, Xu LS: Effects of vacuum-assisted closureon wound microcirculation: an experimental study. Asian JSurg 2005, 28(3):211-217.
  2. Wackenfors A, Sjogren J, Gustafsson R, Algotsson L, Ingemansson R,Malmsjo M: Effects of vacuum-assisted closure therapy oninguinal wound edge icrovascular blood flow. Wound RepairRegen 2004, 12(6):600-606.
  3. Saxena V, Hwang CW, Huang S, Eichbaum Q, Ingber D, Orgill DP:Vacuum-assisted closure: icrodeformations of wounds andcell proliferation. Plast Reconstr Surg 2004, 114(5):1086-96; discussion1097-8.
  4. Greene AK, Puder M, Roy R, Arsenault D, Kwei S, Moses A, OrgillDP: Microdeformational wound therapy: effects on angiogenesisand matrix metalloproteinases in chronic wounds of 3debilitated patients. Ann Plast Surg 2006, 6(4):418-422.
  5. Milano CA, Kesler K, Archibald N, Sexton DJ, Jones RH: Mediastinitisafter coronary artery bypass graft surgery. Risk factorsand long-term survival. Circulation 995, 92(8):2245-2251.
  6. Braxton JH, Marrin CA, McGrath PD, Ross CS, Morton JR, NorotskyM, Charlesworth DC, Lahey SJ, Clough RA, O'Connor GT: Mediastinitisand ong-term survival after coronary artery bypassgraft surgery. Ann Thorac Surg 2000, 70(6):2004-2007.
  7. Gustafsson RI, Sjogren J, Ingemansson R: Deep sternal woundinfection: a sternal-sparing technique with vacuum-assistedclosure therapy. Ann Thorac Surg 2003, 76(6):2048-53; discussion2053.
  8. Sjogren J, Gustafsson R, ilsson J, Malmsjo M, Ingemansson R: Clinicaloutcome after poststernotomy mediastinitis: vacuumassisted closure versus conventional treatment. Ann ThoracSurg 2005, 9(6):2049-2055.
  9. Sjogren J, Nilsson J, Gustafsson R, Malmsjo M, Ingemansson R: Theimpact of vacuum-assisted closure on long-term survivalafter post-sternotomy ediastinitis. Ann Thorac Surg 2005,80(4):1270-1275.
  10. Lindstedt S, Malmsjo M, Ingemansson R: Blood flow changes innormal and ischemic myocardium during topically ppliednegative pressure. Ann Thorac Surg 2007, 84(2):568-573.
  11. Lindstedt S, Malmsjo M, Sjogren J, Gustafsson R, Ingemansson R:Impact of different topical negative ressure levels on myocardialmicrovascular blood flow . Cardiovasc Revasc Med inpress.
  12. Wackenfors A, Gustafsson R, Sjogren J, Algotsson L, Ingemansson R,Malmsjo M: lood flow responses in the peristernal thoracicwall during vacuum-assisted closure therapy. Ann Thorac Surg2005, 79(5):1724-30; discussion 1730-1.
  13. Zografos GC, Martis , Morris DL: Laser Doppler flowmetry inevaluation of cutaneous wound blood flow using varioussuturing techniques. Ann Surg 1992, 215(3):266-268.
  14. Armstrong DG, avery LA: Negative pressure wound therapyafter partial diabetic foot amputation: a multicentre, randomisedcontrolled trial. Lancet 2005, 366(9498):1704-1710.
  15. orykwas MJ, Argenta LC, Shelton-Brown EI, McGuirt W: Vacuumassistedclosure: a new method for wound control and treatment:animal studies and basic foundation. Ann last Surg 1997,38(6):553-562.
  16. Argenta LC, Morykwas MJ: Vacuum-assisted closure: a newmethod for wound control and treatment: clinical experience.Ann Plast Surg 997, 38(6):563-76; discussion 577.
  17. Vandenburgh HH: Mechanical forces and their second messengersin stimulating cell growth in vitro. Am J Physiol 1992, 262(3Pt ):R350-5.
  18. von Ahn HC, Ekroth R, Nilsson GE, Svedjeholm R: Assessment ofmyocardial perfusion with laser Doppler flowmetry. Anexperimental study on porcine heart. cand J Thorac CardiovascSurg 1988, 22(2):145-148.
  19. Brazier JR, Cooper N, McConnell DH, Buckberg GD: Studies of theeffects of hypothermia on regional myocardial lood lowand metabolism during cardiopulmonary bypass. III. Effectsof temperature, time, and perfusion pressure in fibrillatinghearts. J Thorac Cardiovasc Surg 1977, 3(1):102-109.
  20. Buckberg GD, Brazier JR, Nelson RL, Goldstein SM, McConnell DH,Cooper N: Studies of the effects of hypothermia on regionalmyocardial blood flow and etabolism during cardiopulmonarybypass. I. The adequately perfused beating, fibrillating,and arrested heart. J Thorac Cardiovasc Surg 1977, 73(1):87-94.
  21. Hottenrott C, uckberg GD, Maloney JV Jr.: Effects of ventricularfibrillation on distribution and adequacy of coronary bloodflow. Surg Forum 1972, 23(0):200-202.
  22. Buckberg GD, ottenrott CE: Ventricular fibrillation. Its effecton myocardial flow, distribution, and performance. Ann ThoracSurg 1975, 20(1):76-85.
  23. Kang S, Yang Y: Coronary icrovascular reperfusion injuryand no-reflow in acute myocardial infarction. Clin Invest Med2007, 30(3):E133-45.
  24. van Gaal WJ, Banning AP: Percutaneous coronary nterventionand the no-reflow phenomenon. Expert Rev Cardiovasc Ther 2007,5(4):715-731.
  25. Shyu KG, Chang ML, Wang BW, Kuan P, Chang H: Cyclicalmechanical tretching increases the expression of vascularendothelial growth factor in rat vascular smooth musclecells. J Formos Med Assoc 2001, 100(11):741-747.
  26. Seko Y, Seko Y, akahashi N, Shibuya M, Yazaki Y: Pulsatile stretchstimulates vascular endothelial growth factor (VEGF) secretionby cultured rat cardiac myocytes. Biochem Biophys Res ommun1999, 254(2):462-465.
  27. Rosengart TK, Lee LY, Patel SR, Sanborn TA, Parikh M, Bergman GW,Hachamovitch R, Szulc M, Kligfield PD, Okin PM, Hahn RT, DevereuxRB, Post MR, Hackett NR, Foster T, Grasso TM, Lesser ML, IsomOW, Crystal RG: Angiogenesis gene therapy: phase I assessmentof direct intramyocardial dministration of an adenovirusvector expressing VEGF121 cDNA to individuals withclinically significant severe coronary artery disease. Circulation1999, 100(5):468-474.
  28. eon MB, Kornowski R, Downey WE, Weisz G, Baim DS, Bonow RO,Hendel RC, Cohen DJ, Gervino E, Laham R, Lembo NJ, Moses JW,Kuntz RE: A blinded, randomized, lacebo-controlled trial ofpercutaneous laser myocardial revascularization to improveangina symptoms in patients with severe coronary disease. JAm Coll Cardiol 2005, 6(10):1812-1819.
  29. Cohn PF: Enhanced external counterpulsation for the treatmentof angina pectoris. Prog Cardiovasc Dis 2006, 49(2):88-97.