Anterior cervical fusion and plate fixation is an effective procedure for the treatment of cervical myelopathy or radiculopathy and cervical spine trauma. Plating has been reported to achieve a fusion rate of up 98%, and to result in early mobilization, reduced graft-related complications (especially for multilevel fusion), and to avoid late deterioration of the cervical spine alignment obtained at surgery
1,4). The complication rate after anterior cervical plating is generally low and decreases with surgeon's experience. According to Zeidmann
14), the overall complication rate associated with anterior cervical spinal fusion is approximately 5%, and pharyngo-esophageal perforation is uncommon, but nevertheless of the utmost importance because of the possibility of graft infection leading to osteomyelitis, mediastinitis, sepsis, and death
6). Surgical causes of esophageal perforation may be subdivided into acute or delayed. Acute injury can be caused iatrogenically during surgical approach due to inappropriate placement or dislodgement of sharp-toothed retractor blades in the esophagus. Retraction is particularly dangerous when a nasogastric tube is positioned because the wall of the hypopharynx or esophagus may be "trapped" by a high-pressure claw between the retractor and the tube, causing ischemic injury and secondary perforation
8). Delayed esophageal injuries are due to chronic compression or contact and subsequent necrosis, abscess formation, and perforation due to graft dislodgement or screw migration with or without plate failure
4,7). Screw dislodgement often follows a benign course and is completely asymptomatic, due to the small diameters of the screws used and slow migration from the external to the internal mucosa, which permits spontaneous tissue repair of the defect caused. Migrated screws can be eliminated through the gastrointestinal tract
3,5). Repetitive friction between the retropharyngo-esophageal wall and the plating system(normally positioned with adhesion), traction-type pseudodiverticulum, and perforation are other causes of delayed injury
11). The complications of esophageal perforation range from asymptomatic with local infection to mediastinitis and death. The clinical course depends on the etiology, location, and timing of the perforation. Asymptomatic perforation has as well been reported as incidental oral extrusion of screw even years after anterior cervical spine stabilization
5). Patients generally present with swallowing difficulty, regional swelling, neck pain, dysphagia, weight loss, dysphonia, subcutaneous emphysema, and fever; our patient presented with dysphagia and neck pain with regional swelling
12,13). Conservative treatment may be preferred for small, contained defects of less than 1 cm, and consists of the elimination of oral feeding, tube feeding to restore fluid and nutritional balance, and intravenous antibiotics. Some cases need surgical repair, such as, perforation closure with a primary suture or sternocleidomastoid or pectoralis major flap repair
13). We operated on our patient to remove the offending screw due to evident fistula confirmed by esophagography and esophagoscopy. Direct repair was effective in achieving a successful perforation repair of the esophageal perforation with an early return to oral feeding.