A medical complex was a type of medical facility.
Doctor Surmak Ren was chief administrator of the Ilvian Medical Complex on Bajor. (DS9: "Babel")
After graduating, Julian Bashir was offered a job in a medical complex in Paris. (DS9: "Armageddon Game")
Terrasphere 8, a species 8472 re-creation of parts of San Francisco, included the Starfleet Medical complex. (VOY: "In the Flesh")