New continuous-flow total artificial heart and vascular permeability.

Area of Science:

• Cardiovascular Surgery
• Biomedical Engineering
• Vascular Biology

Background:

• Investigating the short-term effects of pulsatile versus nonpulsatile circulation after ventricular replacement with total artificial pumps.
• Utilizing an animal model to assess peripheral vascular permeability changes.

Purpose of the Study:

• To evaluate the impact of continuous-flow total artificial heart (CFTAH) support with and without pulse pressure on peripheral microvascular permeability.
• To determine if CFTAH implantation leads to endothelial injury or increased vascular permeability in skeletal muscle.

Main Methods:

• Ten calves received HeartMate III continuous-flow rotary pumps for cardiac replacement.
• Five calves received pulsatile pump speed modulation (PP), while five received nonpulsatile circulation (NP).
• Skeletal muscle biopsies analyzed for water content, morphology, and specific vascular proteins (VE-cadherin, phospho-VE-cadherin, CD31) at baseline and post-operative days 1, 7, and 14.

Main Results:

• No significant changes in skeletal muscle tissue water content or morphology were observed within or between groups.
• No significant alterations in VE-cadherin, phospho-VE-cadherin, or CD31 expression/distribution in skeletal muscle vasculature.
• CFTAH with or without pulse pressure showed a non-significant trend towards increased tissue water and histologic damage at later time points.

Conclusions:

• Short-term CFTAH support, with or without pulse pressure, did not cause significant peripheral endothelial injury.
• No increase in peripheral microvascular permeability was detected in the calf model.
• Adherens-junction protein analysis showed no significant degradation or phosphorylation, supporting the absence of endothelial damage.