Left atrio-oesophageal fistula after atrial fibrillation ablation

Background

Atrial fibrillation is one of the most common arrhythmias and is often successfully managed with medical treatment. In specific scenarios, patients need an interventional approach involving isolating the pulmonary veins around their ostia using catheter ablation. The complication rate of the procedure is low, and some of them include pericardial effusion, stroke, vascular injuries, phrenic nerve palsy, pulmonary vein stenosis and atrio-oesophageal fistula (AOF).1

AOF is a rare but potentially life-threatening complication of the ablation procedure that manifests 1–8 weeks after the procedure.1 High clinical suspicion, early diagnostic and treatment interventions are needed to prevent a fatal outcome. We present a case of AOF presenting with weakness and stroke symptoms, 4 weeks after cryoballoon ablation performed for uncontrolled atrial fibrillation.

Case presentation

A 68-year-old woman with a medical history of diabetes milletus, atrial fibrillation and obstructive sleep apnea presented to the emergency department because of weakness, lethargy, vague chest discomfort and multiple falls in the last 2 days. She had recently been given a course of azithromycin for a non-productive cough and subjective fevers, without much help. She also reported fluctuating weakness of the left side of the body. Four weeks earlier, she had undergone a cryoballoon ablation procedure for uncontrolled atrial fibrillation with medical therapy. She had been feeling weak and experiencing a vague chest discomfort since the procedure. She denied any headaches, seizures, numbness, loss of consciousness, nausea or vomiting.

On examination, she was awake, alert and oriented, had mild tachypnoea, but was able to speak in full sentences. Her vital signs included a temperature of 102.8°F, blood pressure of 98/51 mm Hg, pulse rate of 70/min, respiratory rate of 18/min and 90% oxygen saturation on room air. Lung auscultation revealed few crackles at the lung bases. The cardiac rhythm was regular, and there was no murmur. She had motor weakness of the left side (2/5 strength) but no sensory deficits. Interestingly, her motor weakness had entirely resolved on the physical examination performed a few hours later.

Investigations

Laboratory testing showed normal complete blood counts (white blood cells: 5×10⁹/L) and serum chemistries but elevated lactic acid (3.1 mmol/L) and procalcitonin levels (28.5 ng/mL). Chest X-ray showed mild interstitial oedema, but no significant infiltrates. Due to the neurological symptoms and ongoing fever and cough, CT scans of the brain and chest were performed. CT chest showed an air collection in the mediastinum between the posterior left atrial wall and the oesophagus, suspicious for a fistula (figure 1). CT brain performed in the emergency room did not reveal any acute process. However, due to fluctuating neurological symptoms, an MRI brain was performed the next morning and showed acute infarction in the bilateral frontoparietal regions, suggestive of an embolic phenomenon (figure 2). An oesophagogram (using gastrograffin) performed to look for any oesophageal leak into the mediastinum was negative.

Differential diagnosis

Pneumonia was considered based on cough, fever and elevated procalcitonin levels, but chest imaging did not show any infiltrates. Acute ischaemic and haemorrhagic stroke were also in the differential list, but brain imaging ruled them out. AOF leading to air embolism was confirmed based on the history of recent catheter ablation, imaging showing fistula between the left atrium and the oesophagus, and MRI brain suggesting embolic phenomena.

Treatment

Broad-spectrum antibiotics were initiated to treat mediastinitis. Our initial plan was to perform an upper endoscopy to look for the site of oesophageal injury and place a stent if needed. However, the cardiothoracic team strongly advised against the endoscopy procedure (explained in the Discussion section). The patient was transferred to a tertiary care centre for surgical management of the AOF. She underwent right thoracotomy for oesophageal mobilisation, the takedown of fistula and the primary repair of oesophageal perforation. The surgeon used the intercostal muscle flaps to reinforce the oesophagus.

Over the next few days in the intensive care unit, she received mechanical ventilation, parenteral nutrition and intravenous antibiotics (ampicillin–sulbactam). She was successfully extubated after 48 hours and placed on a nasal cannula. Oral intake was initiated after another normal oesophagogram. Over the next few days, she completed the antibiotic course, came off supplemental oxygen and parenteral nutrition.

Outcome and follow-up

The patient got discharged to a rehabilitation facility after 10 days of hospitalisation. After completing the rehabilitation, she successfully went home and continues to follow-up in the clinic for her other comorbidities.