Laser Doppler flowmetry assessment of peristernal perfusion after cardiac surgery: beneficial effect of negative pressure therapy.

Negative pressure therapy has been successfully applied to clean, closed incisions in patients at high-risk for wound complications. Using laser Doppler flowmetry, we evaluated peristernal perfusion after cardiac surgery via median sternotomy, assessing the influence of mammary artery harvesting and the impact of negative pressure therapy. Twenty adult patients underwent median sternotomy for cardiac surgery followed by routine closure. Negative pressure was applied at 125 mm Hg for 4 days postoperatively in patients with increased risk for wound complications (n = 10, negative pressure group); standard dressings were applied to control incisions postoperatively (n = 10). Presternal perfusion was determined at baseline and daily for 4 days postoperatively using laser Doppler flowmetry. Results within and between groups were compared with analysis of variance. No wound complications were encountered in either group. Perfusion increased among the patients who underwent negative pressure therapy and decreased among the controls (P = 0.004). Mammary artery harvesting reduced peristernal perfusion by 25.7% in the controls, but negative pressure increased perfusion by 100% after mammary harvesting (P = 0.04). Negative pressure therapy increased perfusion relative to controls and compensated for reduced perfusion rendered by mammary artery harvesting, providing additional support for 'well wound therapy' in high-risk patients.

Does negative pressure wound therapy have a role in preventing poststernotomy wound complications?

BACKGROUND: Sternal wound infection (SWI) remains a devastating complication after cardiac surgery, decreasing long-term and short-term survival. In treating documented SWI, negative pressure wound therapy (NPWT) reduces wound edema and time to definitive closure and improves peristernal blood flow after internal mammary artery (IMA) harvesting. The authors evaluated NPWT as a form of "well wound" therapy in patients at substantial risk for SWI based on existing risk stratification models. METHODS: Records of 57 adult cardiac surgery patients (September 2006 to April 2008) were reviewed. After preoperative risk assessment, NPWT was instituted on the clean, closed sternotomy immediately after surgery and continued 4 days postoperatively. Adverse postoperative events, including SWI, need for readmission, and other complications, were documented. RESULTS: Mean age was 60.4 +/- 10 years, and 89.5% were male; 77.2% were obese (mean body mass index 35.3 +/- 6.7), 54.4% were diabetic, and 29 (50.9%) were both obese and diabetic. Coronary artery bypass (CAB) with single IMA was performed in 50.9% of the patients followed in frequency by combined CAB/valve, non-CAB surgery, and CAB with bilateral IMA. Estimated risk for SWI was 6.1 +/- 4%. All patients tolerated NPWT to completion. Thirty-day and in-hospital mortality was 1.8% and unrelated to DSWI. No treatment of SWI was required. CONCLUSIONS: In this high-risk cohort, 3 postoperative SWI cases were anticipated but may have been mitigated by NPWT. This is an easily applied and well-tolerated therapy and may stimulate more effective wound healing. Among patients with increased SWI risk, strong consideration should be given to NPWT as a form of "well wound" therapy.