Effect of Skeletonization of Bilateral Internal Thoracic Arteries on Deep Sternal Wound Infections

Abstract

Bilateral internal thoracic arteries (BITA) coronary bypass grafting may improve long-term outcomes but is associated with increased deep sternal wound infections (DSWIs). We analyzed whether BITA skeletonization impacts DSWIs and operative mortality (OM) using The Society of Thoracic Surgeons Adult Cardiac Surgery Database. Primary, isolated, nonemergent/nonsalvage BITA patients (July 2017 to December 2018) in The Society of Thoracic Surgeons Adult Cardiac Surgery Database were divided into groups based on BITA harvesting technique: both skeletonized (ssBITA) and ≥1 nonskeletonized (Non-ssBITA). DSWI and OM observed-to-expected (O/E) ratios were compared using The Society of Thoracic Surgeons Perioperative Risk Models. ssBITA versus Non-ssBITA DSWI and OM adjusted odds ratios were calculated by multivariable logistic regression and corroborated by propensity score matching. We analyzed 11,269 patients (42.8% ssBITA, 57.2% Non-ssBITA, 770 hospitals, 1448 surgeons). The ssBITA group had a higher incidence of comorbidities and off-pump surgery. Overall incidences of DSWIs and OM were 0.98% (O/E ratio, 5.1) and 1.72% (O/E ratio, 1.4), respectively, and were 28% (P= .129) and 23% (P= .096) lower in ssBITA. The DSWI O/E ratio was highest (5.9) in Non-ssBITA and lowest in ss-BITA (4.1). After multivariable adjustment, ssBITA was associated with a decreased risk of DSWIs (adjusted odds ratio, 0.66; 95% confidence interval, 0.44-1.00; P= .05), with no difference in OM. These results were confirmed among 3884 propensity score-matched pairs. DSWIs increased sharply with increasing number of risk factors for DSWIs regardless of harvesting technique, with a trend for higher DSWIs among Non-ssBITA for all risk categories. The observed high O/E ratio indicates that BITA grafting is associated with increased risk of DSWIs. Risk-adjusted DSWI rate and a lower O/E ratio in ssBITA support the protective role of skeletonization.