"According to the National Center for Biotechnology Information (NCBI), retained surgical bodies after a procedure is an issue for surgeons and hospitals. They estimate surgical instruments get left inside patients between 0.3 to 1.0 per 1,000 abdominal operations."
"And yet, it happens more often than many of us would like to admit. A 2012 study by Johns Hopkins University found that surgeons left foreign objects inside their patients' bodies at least 39 times a week."
"Approximately 70% of the items left in patients' bodies are sponges, according to a 2003 study in the New England Journal of Medicine. The remaining 30% are surgical instruments such as clamps and retractors. Otherwise known as retained surgical items, these objects can cause localized pain, discomfort and bloating."