Vacuum-Assisted Closure Therapy - A new Treatment Modality in Poststernotomy Mediastinitis

Sammanfattning: Poststernotomy mediastinitis is a devastating complication associated with median sternotomy, which occurs mainly after cardiac surgery. The optimal treatment is still controversial. The aim was to develop, describe and evaluate a surgical procedure consisting of vacuum-assisted closure (VAC) in combination with delayed primary closure in patients with mediastinitis. A porcine sternotomy wound model was created to investigate if super-physiological negative pressures affect peristernal tissues and respiratory parameters. It was concluded that early VAC therapy followed by delayed primary closure, guided by the plasma C-reactive protein level is a reliable and easily applied new strategy in patients with poststernotomy mediastinitis. This modified therapy is a safe and reproducible option to bridge patients with deep wound infection to complete healing with low morbidity and mortality rates. Reconstruction of the preserved sternum was achieved in forty patients without the use of muscle or omental flap surgery. Furthermore, vacuum-assisted sternal closure induces a change in microvascular blood flow that is dependent on the pressure applied, the distance from the wound edge, and tissue type. Wound fluid oxygenation and lactate levels increased in vacuum-exposed tissues. This may be a key to further understanding of the mechanisms by which VAC therapy enhances wound vascularity and formation of granulation tissue. Additionally, the findings following sternal VAC application suggest that respiratory physiology and oxygenation were not affected, when pressures ranging from -50 mmHg to -175 mmHg were compared.