Oesophagocutaneous fistula after removal of anterior cervical fusion hardware

A 63-year-old male with a history of anterior cervical spinal fusion initially presented with dysphagia. Imaging revealed displacement of the anterior plate and a screw, prompting the decision to remove the hardware. A surgical drain was left in place postoperatively. Two days following surgery, milky discharge was noted in the drainage catheter after the patient had ingested milk.

Initial single contrast oesophagram showed pooling of contrast in the right lateral aspect of the oesophagus adjacent to the drain, concerning for an oesophagal leak.

Subsequent computed tomography (CT) of the neck with intravenous and oral contrast demonstrated a curvilinear tract extending from the proximal infrahyoid oesophagus to the skin surface at the right anterior neck consistent with an oesophagocutaneous fistula.

Background

Fistulas are abnormal tracts between two epithelial-lined surfaces and can occur as a result of iatrogenic injury, infection, penetrating trauma, malignancy, or an inflammatory process such as Crohn’s disease. Esophagocutaneous fistula specifically is a rare complication of cervical and thoracic surgeries. Although rare, there have been similar cases of oesophagal injury and subsequent fistulisation. The incidence of presentation of oesophagal perforation in anterior cervical spine surgery is 0.2-0.4% in some studies and less than 0.1% in others [1,2]. The formation of a fistula is a consequence of direct intraoperative oesophagal injury resulting in leakage of oesophagal content into the surrounding tissues and can present in the immediate postoperative period or within the first few months following surgery.

Clinical Perspective

Findings concerning for oesophagal injury and subsequent fistulisation include presence of oral or ingested contents in drainage catheters, fever, chills, and increased postoperative neck pain. The formation of an oesophagocutaneous fistula is the direct result of intraoperative oesophagal injury, leading to leakage of pharyngeal and oesophagal contents into the surrounding soft tissues which may form a tract, usually presenting within days to months following surgery [2,3].  For comparison, a delayed presentation of pharyngoesophageal perforation has been reported in 0.2-1.5% of cases following anterior approach to cervical spinal surgery with an average time to diagnosis of two years [4]. The most important aetiology of oesophagal injury in the late postoperative period is displacement or fracture of the cervical spine hardware [5].

Imaging Perspective

Diagnosis of oesophagal injury is made with upper gastrointestinal imaging with water-soluble positive oral contrast, such as oesophagram or oral contrast-enhanced neck computed tomography (CT). CT imaging may be preferred to evaluate for abscess formation. The findings consistent with diagnosis of oesophagal injury would include extravasation of contrast material into the tissues surrounding the oesophagus, possibly with pneumomediastinum or subcutaneous emphysema [6]. 

Outcome

The morbidity and mortality of oesophagal injury following spinal surgery remain as high as 20% for those detected and treated within 24 hours. Delay in treatment has a mortality rate of approximately 50% [7]. Surgical repair of perforation and fistulisation is largely preferred over conservative management due to the high morbidity and mortality, particularly in patients with adjacent abscess formation [8]. However, there have been reports of successful conservative management in these patients, mainly attributed to the timing between surgery and diagnosis of the fistula, in addition to the degree of perforation and calibre of the fistula tract [9].

Overall, treatment options depend on the size and output of the fistula and can range from conservative management, as in this case, to surgical intervention. It can be expected that the majority of narrow-calibre, low-output fistulas will spontaneously resolve within 4-6 weeks [10]. The common treatment for patients who have undergone anterior cervical fusion and subsequently developed oesophagal injury and fistulisation would be to remove the hardware, perform a posterior fusion, primary closure of oesophagal injury, antibiotic therapy, and keeping patients nil per os (NPO) [9].

Take-Home Message/Teaching Points:

While oesophagal injury is not an uncommon complication of cervical and thoracic surgeries, esophagocutaneous fistula formation is rare. Most esophageal injuries present immediately postoperatively, while a small number esophagocutaneous fistulas may present up to two years later. Abnormal discharge of food material from a wound or drainage catheter should always raise suspicion of fistula formation. Diagnosis is made with oral contrast-enhanced upper gastrointestinal imaging. Conservative management can be considered with low-output fistulas, however surgical management may be preferred due to the risk of further infection and complications.