Management with closed irrigation for post-sternotomy mediastinitis: experience with the use of electrolyzed strong acid aqueous solution.

Objective: The aim of this study was to assess the adequacy of our treatment strategy for patients with post-sternotomy mediastinitis.

Methods: Between May 1997 and December 2000, 1,045 consecutive adult cardiac operations were performed at our center. Mediastinitis occurred in 8 patients (0.77%) and as treatment, they underwent (1) aggressive debridement, (2) closed irrigation and drainage, and (3) transvenous administration of antibiotics. We irrigated the mediastinum with 0.1-1.0% povidone-iodine solution, alternating with electrolyzed strong acid aqueous solution. We subsequently reviewed the outcome after the closed irrigation treatment for patients with post-sternotomy mediastinitis.

Results: In four of the 8 patients, the culture specimen grew Methicillin-resistant Staphylococcus aureus. In the others, Serratia marcescens, Staphylococcus epidermidis, Pseudomonas aeruginosa and Gram-negative rods were cultured. The mean period between primary surgery and the diagnosis of mediastinitis was 16.3 (8 -57) days. The mean period between diagnosis of mediastinitis and the start of the irrigation treatment was 0.8 (0-3) days. The mean irrigation period was 30.0 (14-47) days. The irrigation complications were mild hepatic dysfunction in 2 patients, hyponatremia in 2 and protracted wound infection in 1. The hospital mortality was 1/8 (12.5%). Seven survivors are free from recurrent mediastinitis.

Conclusions: Our experience of closed irrigation and drainage suggests that it can yield satisfactory results after post-sternotomy mediastinitis, comparable to other reported results with or without muscle flaps.