A Collis gastroplasty is a surgical procedure performed when the surgeon desires to create a Nissen fundoplication, but the portion of esophagus inferior to the diaphragm is too short. Thus, there is not enough esophagus to wrap. A vertical incision is made in the stomach parallel to the left border of the esophagus. This effectively lengthens the esophagus. The stomach fundus can then be wrapped around the neo-esophagus, thus reducing reflux of stomach acid into the esophagus.
It was devised by John Leigh Collis (1911–2003), a British cardiothoracic surgeon, in 1957.