The hypopharynx extends from the hyoid bone to the inferior border of the cricoid cartilage. It connects to the trachea ventrally and the esophagus posteriorly at the level of the sixth cervical vertebra (2). The esophagus, approximately 23 to 25 cm in length, ends distally just ventral to the 11th thoracic vertebrae. In relation to surrounding structures, the esophagus rests upon the vertebral bodies and longus colli muscles, which are located posteriorly. It is bordered ventrally by the trachea and flanked on either side by the carotid arteries.

The true incidence of esophageal perforation remains unknown and is likely underestimated (3, 4 and 5). Early studies looking at complications from ventral cervical procedures had few references to this injury: Cloward (3) did not mention esophageal perforation in his series, and Tew et al. only had one documented case in their series consisting of 500 cases. Newhouse et al. (6) surveyed all members of the Cervical Spine Research Society and found the reported incidence to be 0.25%. More recent large reviews have indicated that the incidence ranges from 0.2% to 0.4% (8). Studies have shown that esophageal injuries are more likely to occur during surgery for cervical spine trauma than in surgery for degenerative disease (7,9,10). The levels most frequently affected are C5-C6 and C6-C7 due to the fact that these levels are the ones most frequently operated upon.

Esophageal perforations are classified as intraoperative or delayed postoperative complications. Intraoperative esophageal injuries are typically iatrogenic, and their clinical manifestations occur in the early postoperative period. These injuries occur secondary to errant retractor placement, overzealous manual retraction, or direct laceration from use of sharp instruments (2). Delayed postoperative injuries can occur months to years after the original surgery. They are typically due to failure or migration of hardware with resulting
chronic compression. Newhouse et al. (7) noted that the majority of cases recognized after surgery were due to direct irritation of the esophagus by metal, bone, or cement.