Corpus Sterni Reinforcement Improves the Stability of Primary Sternal Closure in High-Risk Patients

Median sternotomy - gold standard incision for cardiac surgeons

Sternotomy is the gold standard incision for cardiac surgeons but it is also used in thoracic surgery especially for mediastinal, tracheal and main stem bronchus surgery. The surgical technique is well established and identification of the correct anatomic landmarks, midline tissue preparation, osteotomy and bleeding control are important steps of the procedure. Correct sternal closure is vital for avoiding short- and long-term morbidity and mortality. The two sternal halves have to be well approximated to facilitate healing of the bone and to avoid instability, which is a risk factor for wound infection. New suture materials and techniques would be expected to be developed to further improve the patients evolution, in respect to both immediate postoperative period and long-term morbidity and mortality.

Vacuum-assisted closure and bilateral pectoralis muscle flaps for different stages of mediastinitis after cardiac surgery

PURPOSE

To assess the results of bilateral pectoralis major muscle flaps (BPMMF) and vacuum-assisted closure (VAC) at different stages of postcardiac surgery mediastinitis.

METHODS

Of 65 patients with a deep sternal wound infection (DSWI) after cardiac surgery, 33 with a stable sternum were treated with VAC (59.3 +/- 11.7 years of age) and 32 with an unstable sternum or osteomyelitis (63.3 +/- 9.8 years of age) were treated with early BPMMF and continuous irrigation. Delayed BPMMF reconstruction was necessary in six VAC patients.

RESULTS

The overall incidence of DSWI was 1.04% within the study period. Deep sternal wound infection was diagnosed 15.9 +/- 10.8 days (range 5-62 days) after surgery. Diabetes was more common in the BPMMF group than in the VAC group (P = 0.046). Hospital mortality after treatment was 4.6% (n = 3) overall. Causes of death were septic multiorgan failure and respiratory failure. The infective pathogens were methicillin-resistant Staphylococcus aureus (MRSA; n = 2) and Acinetobacter species (n = 1). The median hospital stay was 29 days (range 15-110 days). After 6 months, only one recurrent sternal infection had occurred in the VAC group.

CONCLUSIONS

Early BPMMF is an effective surgical treatment for DSWI in patients with an unstable sternum and osteomyelitis. VAC may be considered for patients without osteomyelitis but a stable sternum, or as adjuvant therapy in patients with comorbidity.

Performance of a novel sternal synthesis device after median and faulty sternotomy: mechanical test and early clinical experience

BACKGROUND

Reinforcement of chest closure may be required in patients with multiple risk factors of wound dehiscence. Performance of a light, size-adaptable closure reinforcement device (DSS: Sternal Synthesis Device; Mikai SpA, Vicenza, Italy) is presented.

METHODS

A longitudinal median or paramedian incision was performed in artificial sternal models: closure was accomplished with simple interrupted steel wires or reinforced with the DSS. Forces required for separation of the rewired sternal halves during a monotonic tensile test were analyzed. A high velocity traction cycles test was also adopted to simulate the impact of coughing.

RESULTS

After median incision, ultimate load values inducing break of the sternum models were 580 +/- 35 N (Newton) in controls; failure of the test occurred at 1,200 +/- 47 N in the reinforced group (p = 0.0002). More lateral displacement of sternal halves at increasing forces was observed in controls (p = 0.0001). After paramedian incision, ultimate load values inducing break of the constructs were lower in controls (220 +/- 20 N vs 500 +/- 25 N, p = 0.001), which also showed more lateral displacement of sternal halves than the reinforced group (p = 0.002). At the high velocity traction cycles test, the number of cycles required to break the models was lower in controls (2,250 +/- 35 vs 3,855 +/- 48 cycles, p = 0.0001). Preliminary clinical experience in 45 patients showed ease of implantation and low risk of complications.

CONCLUSIONS

The proposed sternal reinforcement device provides substantial sternal support at electromechanical testing after median and faulty sternotomy and may hopefully prevent sternal wires migration and bone fractures in high risk patients.