Surgery has evolved considerably in recent decades. Procedures which were unthinkable even ten years ago are now routinely provided, allowing us to live longer lives.
It is now possible to operate on babies in-vitro, and even replace heart valves using minimally invasive methods (referred to as a TAVI procedure). And in turn, as people live longer, surgeons are now faced with ever more complex health problems. While most surgeons do all they can to protect the health of their patients, there are always risks, and occasionally problems can occur.
Much has been done to mitigate the possibility of errors before, during, and after surgery, including protocols to ensure the correct surgical site is made clear, the patient is identified, the procedure type is confirmed before proceeding, and accounting for the use of surgical supplies and instruments (to avoid the possibility of foreign objects being left inside the body).