Wire Cerclage Versus Rigid Plate Fixation: A Retrospective Cohort Study and Cost-Benefit Analysis on Method of Sternotomy Closure After Cardiac Surgery.

Background: Despite increasing evidence demonstrating the merits of rigid plate fixation over wire cerclage for sternotomy closure, wire cerclage remains the predominant standard of care, largely because of the substantial cost of plating systems and the perceived lack of difference to outcomes.

Aim: This study aimed to compare the incidence of sternal complications between patients receiving rigid plate fixation vs wire cerclage and thereby assess the cost vs benefit of said sternal closure methods.

Methods: A retrospective cohort analysis was performed on patients who underwent open cardiac surgery at a single Australian tertiary centre between January 2019 and January 2023. Data were obtained from the Queensland Cardiac Outcomes Registry. The rate of readmissions for sternal complications were compared between those receiving wire cerclage sternal closure vs rigid plate fixation. Index admissions of each cohort were compared to assess secondary outcomes of hospital length of stay, intensive care unit length of stay, and admission costs, using marginal treatment effects analysis to adjust for differences in the two patient groups. Costs associated with each method of sternal closure were assessed, including those pertaining to readmissions.

Results: A total of 941 patients underwent sternotomy closure with wire cerclage and 67 patients received rigid plate fixation. Patients in the plate fixation group were at higher risk of sternal complications because of a higher body mass index (33 vs 29, p<0.001), bilateral internal mammary artery graft use (22.4% vs 6.9%, p<0.001), and rate of diabetes (37.7% vs 22.2%, p=0.007). Comparing index admissions, the use of rigid plate fixation was associated with a trend towards reduced hospital length of stay (12 vs 14 days) and intensive care unit length of stay (33 vs 45 hours), with similar total admission costs. There were 37 readmissions for sternal wound complications in the study period, all of which occurred in the wire cerclage group (incidence rate 3.9% vs 0%, p=0.17). Majority of readmissions were attributed to deep sternal wound infection (n=21). Each readmission was associated with an average hospital length of stay of 17 days and admission cost of $42,326 Australian dollars. Over the study period, the total cost of readmissions for sternal complications was $1,661,414 Australian dollars.

Conclusion: The use of rigid plate fixation compared with wire cerclage for sternotomy closure was associated with a strong trend towards reduced sternal wound complications, such that the higher initial costs of rigid plate fixation were offset by the substantial costs of said complications. Thus, an argument is made for considering rigid plate fixation as a first-line method of sternotomy closure, regardless of risk profile.