Influence of positive microbial findings on plastic reconstructive surgery outcome in patients with retrosternal osteomyelitis after cardiac surgery

Objectives: Sternal osteomyelitis is a life threatening complication after cardiac surgery requiring a complex multidisciplinary treatment. In severe cases patients need local or free flaps to cover the wound defect after surgical debridement.

Debridement, vacuum-assisted therapy until an aseptic environment is achieved and following secondary surgical coverage as well as primary coverage after debridement independent of microbiological findings are both controversially discussed treatment options.

Methods: From June 2008 until April 2012 33 patients (12 woman and 21 men) with deep sternal wound infections after cardiac surgery were treated in the Department for Plastic, Hand and Reconstructive Surgery. 27 patients received a pectoralis major flap, the other patients were treated with local or free flaps. Microbial probes were taken intraoperatively in all cases. We retrospectively analysed the influence of positive microbiological findings at the time of plastic reconstructive surgery on the re-operation rate and the length of the in hospital stay.

Results: In 15 out of 33 patients we could not find any growth in the microbial results. 3 of 15 patients (20%) had to undergo re-operation. The mean in hospital stay of all patients with negative microbial results was 23 days, in case of a re-operation it was extended to 37 days. Two patients died during the treatment, one because of a lung embolism and one due to multi organ failure.

Of 17 patients with positive microbiological results five patients had to undergo re-operation due to wound healing issues (29%). The mean in hospital stay of all patients with positive microbial results was 33 days, in case of a re-operation it was extended to 47 days. None of the patients died during the treatment.

No significant difference was detected between both groups regarding the re-operation rate (20% vs. 29%, p = 0.56) or the length of the in hospital stay (23 days ± 14 days vs. 33 days ± 37 days, p = 0.55).

Conclusion: Positive microbial findings at the time of plastic reconstructive surgery in patients with deep sternal wound infection are not associated with a higher re-operation rate or a longer in hospital stay.

A prolonged vacuum-assisted therapy to achieve negative microbial results – especially considering its physical, mental and financial consequences – is not mandatory in the treatment of retrosternal osteomyelitis after cardiac surgery.