No abstract

Objective The present study evaluated the smooth muscle functional response and viability of human saphenous vein (HSV) grafts after harvest, and explored the effect of mechanical stretch on contractile responses of porcine saphenous vein (PSV). Design of study The contractile responses (stress, 105N/m2) of de-identified, remnant HSV grafts to depolarizing potassium chloride and the agonist norepinephrine was measured in a muscle organ bath. Cellular viability was evaluated using a methylthiazol tetrazolium (MTT) assay. A PSV model was used to evaluate the effect of radial, longitudinal and angular stretch on smooth muscle contractile responses. Results Contractile responses varied greatly in HSV harvested for autologous vascular and coronary bypass procedures (0.04198×105 N/m2 ± 0.008128 to 0.1192×105N/m2 ± 0.02776). Contractility of the HSV correlated with the cellular viability of the grafts. In the PSV model, manual radial distension of ≥300mmHg had no impact on the smooth muscle responses of PSV to potassium chloride. Longitudinal and angular stretch significantly decreased the contractile function of PSV by 33.16% and 15.26%, respectively. Conclusions There is considerable variability in HSV harvested for use as an autologous conduit. Longitudinal and angular stretching during surgical harvest impair contractile responsiveness of the smooth muscle in saphenous vein. Avoiding stretch-induced injuries to the conduits during harvest and preparation for implantation may reduce adverse biologic responses in the graft (e.g. intimal hyperplasia) and improve patency of autologous vein graft bypasses.

No abstract

No abstract

In this study, PIVA demonstrated a greater sensitivity for detecting acute hemorrhage, return to euvolemia, and iatrogenic fluid overload compared with standard monitoring and SI. PIVA may provide a low-cost, minimally invasive monitoring solution for monitoring and resuscitating patients with perioperative hemorrhage.