1 / 7An elderly dementia patient strangled his own penis after wrapping rubber bands around it and leaving them on for three days. 2 / 7The unidentified 81-year-old had to have emergency surgery in Chicago after the skin on the tip of his member started to rot.3 / 7Yellow and purple patches began to appear on both the shaft and base of his penis because of the lack of blood supply. Doctors claimed his penis could have fallen off if doctors hadn't removed the bands when they did. 4 / 7The African-American man, whose grisly case was published in a medical journal, was originally admitted to hospital due to complications from his diabetes.5 / 7His wife turned medics' attention to the rubber bands, which she said her husband had refused to remove for between two to three days.Doctors at the University of Chicago Medical Centre operated to prevent further degradation. 6 / 7A catheter — a tube put through the urethra — was used to drain the urine that had built up in his bladder because he'd been unable to urinate.7 / 7He recovered well from the surgery but failed to return for a check-up appointment two weeks after leaving the hospital. The patient had originally went to hospital after suffering diabetic ketoacidosis — a potentially deadly reaction to low levels of insulin. His penis was severely swollen and the tip had begun to change in colour and shape. The skin was breaking down and had become gangrenous.