Sternal closure with single compared with double or figure-of-8 wires in obese patients post cardiac surgery

Objectives: Sternal instability and wound infections are major causes of morbidity following cardiac surgery, which is further amplified in high risk patients that include diabetics and patients with high body mass index (BMI). We compare the different outcomes of different sternal wire closure techniques following median sternotomy for cardiac surgery in obese patients. Methods: A comprehensive electronic literature search was undertaken according to PRISMA guidelines from inception to July 2020 to identify all published data comparing single wire sternal closure to either double wire or figure-of-8 techniques following median sternotomy for cardiac surgery in obese patients, defined as a BMI >= 30. Results: Eight studies met the final inclusion criteria; single wire versus double wire sternal closure (n = 2) and single wire versus figure-of-8 wire closure (n = 6). Higher rate of sternal instability was noted in single wire versus double wire closure (22/150 [14.7%] patients vs. 6/150 [4%] patients, p = 0.003, odd ratio [OR] 0.25 [95% confidence interval [CI] 0.10-0.63]). Similarly, sternal instability was higher in single wire vs figure-of-8 wire closure technique (33/2422 [1.3%] vs. 11/8035 [0.1%], p = 0.04 OR 0.30 [95% CI, 0.09-0.96]), respectively. Conclusion: There is benefit in the use of either double or figure-of-8 sternal wire closure techniques over single wire closure in terms of sternal instability. However, as the studies were limited, larger scale comparative studies are required to provide a solid evidence base for choosing the optimal sternal closure technique in this high risk group of patients.