Does the Wiring Technique for Sternal Closure Have an Impact on Wound Healing in Obese Patients?

Objectives: Closure of the sternum is performed using different techniques being mostly dependent on the individual preference of the surgeon. However, there is evidence that figure of eight wiring appears to improve stability. We tested this hypothesis in obese patients looking on the impact of different techniques on wound healing disturbances and sternal instabilities.

Methods: 2958 obese patients (BMI > 30) who underwent cardiac surgery with median sternotomy during 2009 and 2016 at our department were investigated. Four different sternal closure techniques were performed: 1 figure-of-eight, 2 mostly figure-of-eight, 3 mostly single wires and 4 single wires only. Groups were independent regarding age, sex and diabetes mellitus. Postoperative occurrence of overall wound healing disturbances and sternal instabilities requiring wire removal were assessed. Cochran-Armitage Trend test to study the apparent trend of postoperative overall wound healing disturbances was used. Pearson's chi-squared test was used to examine sternal instabilities.

Results: Incidence of overall wound infections in all groups was 10% (figure-of-eight), 11.1% (mostly figure-of-eight), 14% (mostly single wires) and 14.5% (single wires). This correlates significantly with the extent of single wires usage (p = 0.0056, Cochran-Armitage Trend test). Necessity of wire removal showed an incidence of 2.0%, 2.3%, 2.0%, and 4.8% respectively in the four groups and was thus significantly increased in the single wire groups compared with all others (p = 0.01, 1vs4; p = 0.01 2vs4; p = 0.04 3vs4; Pearson's chi-squared test).

Conclusion: The more figure-of-eight wires are used for sternal closure in obese patients the better it is regarding reduction of wound healing disturbances. As figure-of-eight wiring is not demanding and can easily be adjusted accordingly we recommend predominate use for all obese patients and have consequently changed our respective standard operating procedure (SOP).