Hemodynamic effects of the vacuum-assisted closure device on open mediastinal wounds.

ABSTRACT

BACKGROUND: Application of the Vacuum-Assisted Closure device (VAC) to open sternal wounds has negative hemodynamic effects. We hypothesized that the interposition of a muscle flap attenuates these negative hemodynamic effects. MATERIALS AND METHODS: After institutional approval, monitoring lines were placed in anesthetized, ventilated pigs. Through a median sternotomy, sonometric crystals were strategically positioned around the left ventricle. A rectus flap was rotated over the mediastinal wound, and the VAC was placed over the flap. After baseline measurements, a vacuum of 125 mmHg [Group (GP) 1, n = 5] or 50 mmHg (GP2, n = 6) was initiated. Hemodynamics were recorded every 15 min for 1.5 h, and 15 min after cessation of the vacuum therapy. GP3 (n = 6) underwent intermittent VAC cycling (on 5 min/off 2 min). Significance determined by t test. RESULTS: While non-flapped animals had significant detriment in both left ventricular filling volume and cardiac output, flapped animals had insignificant depression of both parameters. CONCLUSION: Application of muscle flaps to sternal wounds prior to VAC therapy significantly attenuates the negative hemodynamic effects seen when the VAC is used alone.