oa Delayed sternal closure - initial clinical experience of a novel device developed in Qatar

Following difficult cardiac surgery delayed sternal closure (DSC) is a recognized method of early post-operative management in patients with hemodynamic instability or severe coagulopathy . DSC is particularly useful in the paediatric & the neonatal age group due to a larger cardiac size relative to the thoracic cavity. The usefulness of DSC has led some centres to pursue the strategy as a preventive method to thwart low cardiac output either routinely or after specific procedures, e.g. Norwood I for hypoplastic left heart syndrome. METHODS OF ACHIEVING DSC: Basically the following three methods have been used: A): Keeping the sternum open without the usage of any mechanical device/strut This method has the obvious drawback of allowing an unstable sternum which compromises the ventilatory, nursing and Physiotherapy. Furthermore, the sternal edges may injure the right ventricle when the patient is moved. B): Solutions crafted in the operating room: Traditionally surgeons have used barrels of syringes or chest tubes to hand craft sternal stents for keeping the sternal edges apart. C): Specifically designed gadgets. There have been several attempts to design & produce sternal stents for DSC. However almost all of these gadgets have the clear design disadvantage of being bulky, encroaching upon and occupying the sub-sternal space. Keeping these deficiencies of the existing solutions for DSC in site, a simple sternal stent was developed, keeping the following objectives as design targets: 1)Allowance and provision of maximum sub-sternal space for oedematous myocardium to expand into. 2)Firm fixation to the sternal edges and restoration of the stability of the thoracic cage. 3)A design free of moving parts, joints, screws, hollow tubes and telescoping cylinders, thus avoiding blood trapping and increased risk of infection. 4)Low profile with minimal obstruction to the view of the anterior mediastinum. 5)Provision of an "off-the-shelf", set of stents of graduated sizes which could be easily secured to patients of various ages and sternal thickness. 6)Freedom to use multiple stents in a single patient, giving maximal stability of the thoracic cage. INITIAL CLINICAL EXPERIENCE: We have successfully used these stents in 2 adult and 12 paediatric patients. Demographics: Average age at procedure 35.6 days (Ranged 1-195 days) Procedures: Arterial switch operation 3, total anomalous pulmonary venous drainage repair 2, truncus arteriosus repair 1, truncus arteriosus and partial anomalous pulmonary venous drainage repair 1, Norwood procedure 1, Hypoplastic arch repair 1, ventricular septal defect closure with coarctation repair 1, Others 2 Duration: Average Duration of stent placement 4 days (1-12) Successful closure: 10 patients, 2 pt. died while weaning from ECMO Infection: 2(10), Discharge from hospital 10. 30 days follow-up (sternal healing/infection) 2 developed deep sternal wound infection and 1 developed wound dehiscence. All healed with dressing and secondary wound closure. All the 10 surviving patients are doing well at present CONCLUSION: our initial experience showed that these stents provided maximal sub-sternal space to accommodate the edematous mediastinal tissue as well as easy visibility & removability. No immediate mechanical, traumatic or life threating infective complications were observed in the observed cohort.