J. Feng1, W. E. Cohn2, S. M. Parnis2, R. R. Clements1, N. R. Sodha1, O. H. Frazier2, F. W. Sellke1 1Brown University School Of Medicine,Surgery,Providence, RI, USA 2Texas Heart Institute,Minimally Invasive Surgical Technology,Houston, TX, USA
Introduction:
We tested the short-term effect of completely nonpulsatile versus pulsatile circulation after ventricular excision and replacement with total implantable pumps in the animal model of calves on peripheral vascular permeability.
Methods:
8 calves underwent cardiac replacement with 2 HeartMate III continuous-flow rotary pumps. In 4 calves, the pump speed was rapidly modulated to impart a low-frequency pulse pressure in the physiologic range (10-25mmHg) at a rate of 30 pulses per minute (PP). The remaining 4 calves were supported with a pulseless systemic circulation and no modulation of pump speed (CP). Skeletal muscle biopsies were obtained before cardiac replacement (baseline) and on postoperative days 1, 7 and 14. Skeletal muscle tissue water content was measured and vascular endothelial (VE)-cadherin (VE), phospho-VE-cadherin (p-VE) and CD31 were analyzed by immuno-histochemistry.
Results:
There were no significant changes in tissue water content within group or between groups at baseline, postoperative days 1, 7 and 14, respectively. There were no significant alterations in the distribution of VE-cadherin, phospho-VE cadherin and CD31 in skeletal muscle vasculature at baseline, postoperative days 1, 7 and 14 within each group or between the two groups (see Figure), respectively. Even though total CRD in both pulse and pulseless pumps caused slight increase in the intensity of phospho-VE-cadherin at postoperative days 7 and 14, it failed to reach statistical significance (See Figure).
Conclusion:
There were no significant VE-cadherin degradation and phosphorylation in the calf skeletal muscle microvasculature after constant-flow total CRD, suggesting that short term of constant flow CRD with or without pulse pressure did not cause peripheral endothelial injury and did not increase the peripheral vascular permeability.
