- Patients with a diagnosis of cervical esophageal diverticulum, with Zenker's as most common, or CP bar (with diagnosis of early Zenker) as indicated on an esophagram who the participating institutions enroll regardless of surgical management and future treatments. Patients undergoing open transcervical or endoscopic approach in which a laser or stapler is used to divide the common wall between the diverticulum and esophagus, or who are not surgical candidates but agree to follow-up.