Atrio-Esophageal Fistula Following Left Atrial Ablation for the Treatment of Atrial Fibrillation: A Report of 2 Cases

Background

Atrial fibrillation (AF) is a common arrhythmia, and treatment with left atrial ablation is a common procedure [1]. Formation of an atrio-esophageal fistula (AEF), resulting from injury to the esophagus, is a rare and extremely dangerous complication of the procedure [2–4]. The injury is mostly due to thermal energy, but is not limited to that and has been reported in other techniques for ablation, such as focused ultrasound and cryoablation. Some preventive measures can be implemented, including esophageal temperature monitoring and others [5]; however, due to the scarcity of patients, there is no uniform approach to diagnosis, prevention, or treatment, and they are mostly reliant on the vigilance of physicians and a rapid response.

We present 2 such cases of AEF following ablation, with the aim of raising awareness to this rare and potentially fatal complication.

Case Reports

CASE 1:

A 67-year-old man had a history of refractory AF, diabetes, arterial hypertension, heart failure with reduced ejection fraction, and chronic kidney disease. Six weeks prior to our hospitalization, he was admitted in another facility with rapid AF that was refractory to treatment and eventually underwent radio-frequency ablation, with no complications reported.

He presented to our facility with a 2-day fever along with left hemiparesis and hematemesis upon entry to the Emergency Department (ED). Head computed tomography (CT) using stroke protocols showed no hemorrhage or major vessel blockage but did reveal acute ischemia in the left distal M3 territory, with no penumbra. He was hospitalized in our Intensive Care Unit (ICU) with the presumption of endocarditis based on the presentation of a febrile illness preceding an embolic cerebral event. By the second day of hospitalization, he rapidly deteriorated with seizures and decreased consciousness, necessitating mechanical ventilation. Repeat CT scan revealed massive ischemic areas in the right middle cerebral artery territories with accompanying edema.

Transthoracic echo showed no vegetation, and due to his hematemesis, a gastroscopy was performed, revealing esophagitis with many blood clots in the stomach; suspicion of a tear was closed with clips. Blood cultures were positive for poly-microbial infection (including multiple streptococcus species).

The patient’s condition continued to deteriorate in the next few days, with dilated pupils and lack of brainstem responses, prompting a third CT scan on day 3, which showed extreme edema and herniation. Based on the history of ablation and the endoscopy findings, a chest CT was added, which revealed evidence of AEF (Figure 1). Owing to his clinical condition, we performed a head positron emission tomography, which showed no perfusion. On the fifth day, a committee declared him brain dead, and after withdrawal of care, he soon died.

CASE 2:

A 64-year-old woman had a history of AF, arterial hypertension, heart failure with reduced ejection fraction, morbid obesity, restrictive lung disease, and chronic kidney disease. Four weeks prior to our hospitalization, she was admitted in the Cardiac Care Unit with refractory AF and an unsuccessful cardioversion attempt, which led to ablation.

According to her family, she was brought due to a fall at home. Upon arrival to the ED, she developed massive hematemesis and epistaxis. She was urgently ventilated to secure the airways and prevent aspiration. The patient was in a state of extreme shock and was rushed to the operating room, where she underwent gastroscopy, revealing only a small tear and blood clots, which was treated with clipping. Afterward, she was transported to our ICU for further treatment.

During the initial hours, the patient was started on broad-spectrum antibiotics, piperacillin-tazobactam and vancomycin; she also required vasopressors and high ventilation pressures. Following a brief stabilization period, the next morning she went into cardiac arrest following ventricular tachycardia. Despite return-of-spontaneous-circulation, her condition continued to deteriorate, with increasing doses of vasopressor, anuria along with rising creatinine levels, and deepening metabolic acidosis with rising lactate levels. Also, on the following morning, blood cultures revealed S. Pneumoniae.

Owing to her medical history and clinical features, we performed a CT scan of the chest and head (Figure 2), which revealed AEF and widespread brain ischemic infarcts in water-shed areas of the left hemisphere along with cerebellum and pons and occipital hemorrhage. The patient’s condition deteriorated, and 5 days after her admission, she died.

Discussion

AF is an extremely common arrhythmia, with some estimates of 2% to 4% lifetime risk, and AEF following ablation cases have been reported and published since 2001 [1,2]. The pathophysiology is not completely understood; however, it is widely assumed that a constant and high radiofrequency delivered to the posterior atrial wall during ablation leads to thermal damage to the esophagus. Some methods were developed to prevent the complication, some with only esophageal temperature monitoring, but also interventional methods, such as the successful esophageal cooling [3].

While the overall prevalence of AEF as a complication of AF ablation is low (up to 0.25% in some reviews), the outcome is usually fatal in non-interventional cases (as high as 97% in some reports) but still high overall (up to 55%) even with intervention such as surgery or endoscopic repair; of those, few survivors remain unscathed without any sequela, predominately neurological [4–6].

The “classic” clinical presentation is a patient that presents up to 60 days (median 21 days) after AF ablation with signs and symptoms consisting primarily of fever and neurological abnormalities in over 70% of cases, even mimicking a cerebral vascular accident [7]; not uncommonly, such as in our cases, these patients present with hematemesis or even hemorrhagic shock.

Since the mortality approaches 100% without treatment and drops to close to 40% with rapid surgical correction [5], rapid diagnosis is of the utmost importance. Aside from a strong clinical suspicion, the modality of choice for diagnosis is CT of the chest. Transthoracic or transesophageal echocardiography are not sensitive enough, and the latter might even worsen the condition. Unfortunately, in patients such as ours, presentations of massive hematemesis necessitate endoscopy, which in these cases can have disastrous consequences. Both our patients showed rapid and profound deterioration, mostly in the form of neurological deficits clinically and radiographically, shortly after the interventions mentioned, emphasizing the need for early recognition and diagnosis.

Following diagnosis, rapid treatment is necessary, with the main options being esophageal stenting or surgical correction. The latter has better survivability but is not always an option due to anatomical and inflammatory changes. Since the literature on the subject is scarce, and the condition is likely underdiagnosed as well, studies are warranted and some are already underway to strengthen our knowledge on the condition [8].

Conclusions

AEF following AF ablation is a rare condition, but left undiagnosed or mistreated, is rapidly hazardous and even fatal. There should be a high level of vigilance for patients following the procedures that present with infectious or neurological abnormalities, and treatment, if deemed necessary, should be performed as rapidly as possible.