Direct mechanical ventricular actuation (DMVA) using the Anstadt Cup can achieve total circulatory support by massaging the fibrillating, asystolic, or failing heart. The device does not contact the blood or cause significant myocardial trauma. The purpose of this study was to assess the functional integrity of saphenous vein grafts (SVGs) subjected to DMVA vs cardiopulmonary bypass (CPB). Human SVGs were used to bypass the ligated left anterior descending coronary artery in 11 dogs. Animals then received 2 hrs of either DMVA (n = 5) or CPB (n = 6) during sustained ventricular fibrillation. Grafted and non grafted (control) SVG segments were then studied in vitro. SVG patency was confirmed by radiolabeled microspheres and pathologic evaluation. Matched SVG specimens (control) were not exposed to circulatory support. All SVGs were subjected to isometric tension studies. SVG contractile responses to norepinephrine, bradykinin, serotonin, and histamine were assessed. Maximal response to all agonists were similar between control SVG segments compared to either CPB or DMVA support (p = NS, ANOVA). All cumulative dose response curves were similar after DMVA vs CPB support. In conclusion, the smooth muscle function of SVGs in this study was not significantly altered by DMVA support. Therefore, short-term DMVA support does not impair patency or adversely effect the functional integrity of smooth muscle within SVGs.
ASJC Scopus subject areas
- Biomedical Engineering