In laparoscopic surgery (key hole surgery) operations are performed by passing instruments down hollow tubes inserted through the abdominal wall. These tubes are called “ports”. The ports vary in diameter from 0.5cm to 1.5cm. When ports of 1cm or more are used, especially in the lower part of the abdomen below the level of the umbilicus, there is a high risk of developing a hernia through the port site (port site hernia) unless the muscle layer and peritoneum (lining of the inner aspect of the abdominal wall) of the port site is sutured. Also it is occasionally necessary to enlarge a port site by stretching it with an instrument in order to deliver for example a large very hard gallstone which cannot be crushed – these may be 3 or 4cm in diameter. In such cases the risk of port site hernia is 100% unless the muscle and peritoneum of the port site is sutured. A port site hernia will require a further operation at a later date to repair it and this can be a very difficult procedure.