We report a case of painful sternal instability following combined open aortic valve replacement and CABG in a 74-year-old Caucasian man. Alongside the surgically treated aortic valve stenosis (grade III) and two-vessel coronary disease, the complicating factors of insulin-dependent diabetes mellitus, obesity (body mass index (BMI) of 40), chronic renal insufficiency, and absolute arrhythmia with atrial fibrillation were present. Due to DSWI with confirmation of massive-scale Staphylococcus epidermidis infiltration, wound revision, necrectomy, and vacuum-assisted closure (VAC) were necessary. Ultimately after three weeks of VAC, secondary closure of the thorax could be performed. Considerable wound pain associated with breathing, palpable sternal instability, and local indications of inflammation persisted in our patient for a further three months. A computed tomography (CT) scan of the thorax conducted in response showed sternal non-union up to six mm wide, an old, organizing hematoma closely surrounding the sternum in a cloak-like manner with a width up to 25 mm, and intact wire stitches (Figure 1). He rejected a repeat surgical wound revision.
We decided in agreement with our patient at his general practitioner's practice to attempt a conservative supportive therapy with an external thoracic support in the form of a customized elastic vest of viscose polyester flat knitwear, with a compression pressure of approximately 20 to 30 mmHg (2.6 to 4 kPa) (Figure 2). Such 'compression garments' have been used for more than 10 years for compression treatment of hypertrophic scarring . Subsequently, the subjective pain intensity decreased within four weeks from a score of eight to nine down to two to three on a visual analog scale of 10 points (100 mm); the need for opioid analgesics was reduced from transdermal fentanyl 100 μg/hour every 72 hours to 12.5 μg/hour every 72 hours. Due to its multi-directional elastic characteristics (approximately 5N/15% fabric stretching), the garment proved itself to be well tolerated even when worn full time under typical everyday conditions. The sternum showed palpatory stability following conservative treatment for three months in total; external scarring was unremarkable. A final CT scan documented completed osseous wound healing and irritation-free connective tissue (Figure 3).