When a patient undergoes chest surgery, it is often necessary for the surgeon to saw through the sternum to gain access to organs such as the heart and lungs. At the end of this surgery, the surgeon will likely insert a cardioprotective patch between the heart and sternum to help reduce complications associated with scar tissue formation, which is then followed by the two halves of the sternum being wired back together. The impact of scar tissue following this procedure is especially important for adults under the age of 65 and pediatric populations, who are at a high likelihood for one or more repeat sternum surgeries in their lifetime. In the US, sternotomies are performed in more than 500,000 patients per year and repeat sternotomies account for about 10% of all cardiac surgeries. Subsequent surgeries to re-open the sternum can take much longer due to reopening of the sternal wires, movement of the cardioprotective patch over time, and the use of CT imaging to assess for scar tissue between the heart and sternum. Despite utilizing a cardioprotective patch, scar tissue can still form, significantly increasing the complications and time for re-opening the chest. As there is limited time for a cardiothoracic surgeon to perform this surgery, every minute spent opening the chest reduces the time it takes to perform the procedure safely and effectively.

In an effort to reduce the incidence of scar tissue formation and improve the ability for surgeons to safely perform repeat sternotomies, cardiothoracic surgeon Dr. Randy Stevens of St. Christopher's Hospital for Children and his colleagues at Drexel University have developed a cardioprotective butterfly device that is placed between the heart and sternum, prior to reconnecting the sternum, when completing an open chest surgery. The material can be of the same composition as that which is currently used, but it also includes a guide that lies directly beneath the sternum. This bone saw guide can be used to assess for the presence of scar tissue and reduce the time it takes to cut through the sternum. Further, it is anchored to keep the membrane in place between the heart and sternum, and its design allows for it to expand as the patient grows. Should subsequent sternum surgeries be required, the surgeon is able to use the guide to align the saw and re-open the sternum both quickly and safely, allowing for more time to perform the procedure. The same technology can also be used in the context of external, orthopedic casts to provide a guide for saws to rapidly open the cast while reducing the possibility of burns or cuts to the patient’s skin during removal.