Most people with an aberrant right subclavian artery (ARSA) never know they have one. This anatomical variant, present in roughly 1–2% of the population, typically causes no trouble at all. When it does produce symptoms, difficulty swallowing is the most recognized complaint, but the full picture ranges from chronic cough and breathing problems in infants to rare, life-threatening bleeding in older adults. The gap between “usually harmless” and “occasionally dangerous” is what makes this vessel worth understanding.
What an Aberrant Right Subclavian Artery Actually Is
Normally, the right subclavian artery branches off the brachiocephalic trunk before heading toward the right arm. In people with ARSA, it instead arises directly from the aortic arch as a separate branch and takes an unusual path behind the esophagus (and sometimes between the esophagus and the trachea) to reach the right side. This detour happens because of the way arteries develop in the embryo, and it is the most common congenital anomaly of the aortic arch.1PubMed Central. Aberrant right subclavian artery: embryology, prenatal diagnosis and clinical significance Because the vessel crosses behind structures it would normally never touch, it can press on the esophagus, the trachea, or both. Whether that pressure is enough to cause symptoms depends on the vessel’s size, its exact route, the person’s age, and whether the artery develops additional problems over time.
Dysphagia Lusoria, the Signature Symptom
The term “dysphagia lusoria” was coined all the way back in 1787 by the English surgeon David Bayford, who described a fatal case of obstructed swallowing caused by an aberrant right subclavian artery compressing the esophagus.2PubMed Central. David Bayford. His syndrome and sign of dysphagia lusoria “Lusoria” comes from the Latin lusus naturae, meaning “freak of nature,” which gives you a sense of how rare and puzzling it seemed at the time. Today, dysphagia lusoria remains the single most common symptom attributed to ARSA, though it still affects fewer than 1% of people who carry the variant.3PubMed Central. Aberrant Right Subclavian Artery Causing Dysphagia: A Case Report of Dysphagia Lusoria
People with dysphagia lusoria typically describe trouble swallowing solid foods more than liquids, sometimes accompanied by a sensation of food getting stuck behind the breastbone. The swallowing difficulty can range from mild and intermittent to severe enough to cause weight loss. Alongside dysphagia, some patients report retrosternal pain (discomfort behind the breastbone) and heartburn-like sensations, which can lead doctors down the wrong diagnostic path toward acid reflux or motility disorders before the vascular cause is identified.4PubMed Central. Symptomatic Aberrant Right Subclavian Artery: Advantages of a Less Invasive Surgical Approach
Why Symptoms Often Appear Later in Life
A puzzling feature of ARSA is that many people live for decades without any symptoms and then develop swallowing difficulty in middle or older age. The artery has been sitting behind the esophagus since birth, so why would it suddenly start causing problems at sixty? The answer involves the artery itself changing. With age, the aberrant vessel can develop atherosclerosis, making it stiffer and less yielding. It may also dilate or form an aneurysm, increasing the amount of pressure it exerts on the esophagus. At the same time, the esophagus loses some of its natural flexibility, making it more susceptible to external compression.5Ochsner Journal. Upper Gastrointestinal Bleeding From Aberrant Right Subclavian Artery-Esophageal Fistula These two processes converge: a stiffening artery pressing against a less compliant esophagus. That is why dysphagia lusoria is predominantly a diagnosis found in adults over fifty, even though the anatomical variant has been present from birth.
Respiratory Symptoms, Especially in Infants and Children
While swallowing trouble is the hallmark in adults, children with ARSA more often present with breathing problems. In infants, the aberrant artery can compress not just the esophagus but also the trachea, which at that age is small and soft enough to be pushed out of shape. Symptoms can include wheezing, stridor (a high-pitched sound during breathing), recurrent pneumonia, persistent cough, and even cyanosis (a bluish tint to the skin from low oxygen).6PubMed Central. Vascular anomaly: Cause of infant respiratory distress and dysphagia Because these symptoms overlap heavily with common childhood conditions like asthma and recurrent respiratory infections, the underlying vascular cause can be missed for months or longer.
In one reported case, a four-month-old boy continued to have persistent respiratory symptoms even after an initial surgery intended to address a different vascular anomaly, and only further imaging revealed that the true anatomy had been misidentified.7PubMed. A double aortic arch mimicking a right aortic arch with an aberrant subclavian artery That case involved a double aortic arch rather than a simple ARSA, but it underscores a broader point: vascular rings and aberrant vessels can produce overlapping symptoms, and accurate imaging is critical before any intervention.
Less Common Symptoms You Might Not Expect
Beyond swallowing difficulty and breathing problems, ARSA has been linked to a handful of symptoms that can stump clinicians precisely because they seem unrelated to a blood vessel behind the esophagus.
Chronic cough is one. In a published case, a young, otherwise healthy man had a persistent cough lasting sixteen months before imaging revealed an ARSA as the sole explanation. He had no swallowing problems at all, and the cough resolved after the vessel was addressed surgically.8PubMed. Aberrant right subclavian artery syndrome: a case of chronic cough The cough is thought to result from the artery irritating or compressing the trachea or nearby nerves rather than the esophagus.
Chest pain is another atypical presentation. An eighteen-year-old woman with no prior medical history was hospitalized for chest pain after emotional stress. Workup eventually pointed to her ARSA as a likely contributor, demonstrating that the anomaly can mimic cardiac pain.9The Russian Archives of Internal Medicine. Chest Pain in the Patient with Arteria Lusoria: A Case Report Cases like these are uncommon enough that chest pain is not something most clinicians immediately associate with an aberrant vessel, which can lead to a prolonged diagnostic journey.
Vascular Complications and Subclavian Steal
Because the aberrant right subclavian artery takes a longer and more tortuous route than a normally positioned vessel, it is more susceptible to developing stenosis (narrowing) or aneurysmal dilation over time. When the artery narrows significantly at its origin, blood flow to the right arm can become insufficient during exertion. The body sometimes compensates by “stealing” blood from the vertebral artery on the right side, reversing its flow to supply the arm instead. This phenomenon is called subclavian steal syndrome.
One reported case involved a forty-five-year-old man with significant right arm cramping during activity and episodes of dizziness, both caused by an occluded aberrant right subclavian artery with steal physiology.10Vascular Surgery. Subclavian Steal Syndrome with Occluded Aberrant Right Subclavian Artery—A Case Report In a small literature review, roughly seven in ten patients with ARSA-related vertebrobasilar insufficiency showed neurological symptoms such as dizziness, blurry vision, fainting, or general weakness, alongside reversed blood flow on Doppler imaging.11Oxford Academic (Journal of Surgical Case Reports). Aberrant right subclavian artery: a case of vertebrobasilar insufficiency Cadaveric studies have also found stenosis at the origin of an ARSA alongside anatomy suggestive of steal, hinting that this may go undiagnosed in people who never had imaging.12Journal of Anatomical Variation and Clinical Case Report. Aberrant Right Subclavian Artery: A Cadaveric Case Study with Anatomy Suggestive of Subclavian Steal Syndrome
Kommerell’s Diverticulum and Aneurysm Risk
At the point where the aberrant right subclavian artery originates from the aorta, a bulge called a Kommerell’s diverticulum may be present. This widening at the vessel’s takeoff occurs in an estimated 20–60% of patients with abnormal subclavian arteries.13PubMed Central. Aberrant right subclavian artery aneurysm with a Kommerell’s diverticulum On its own, a small Kommerell’s diverticulum usually does not cause symptoms, but it represents a weak spot in the arterial wall that can enlarge into a true aneurysm. A growing aneurysm increases compression on the esophagus and trachea, worsening dysphagia and respiratory symptoms, and it carries the risk of rupture, which is a surgical emergency with high mortality.
Life-Threatening Bleeding From Fistula Formation
The rarest and most dangerous complication of ARSA is the formation of a fistula, an abnormal connection between the aberrant artery and the esophagus. When the artery presses against the esophageal wall for years, or when additional factors like prolonged nasogastric tube placement or endotracheal intubation are involved, the constant pressure can erode through the esophageal wall and into the vessel.14PubMed Central. An Aberrant Right Subclavian Artery–Esophageal Fistula—A Fatal Complication of a Common Anomaly: A Case Report and Review of Literature The result is massive upper gastrointestinal bleeding, often presenting as a sudden large-volume hemorrhage that can be fatal on first presentation.5Ochsner Journal. Upper Gastrointestinal Bleeding From Aberrant Right Subclavian Artery-Esophageal Fistula
Patients with a history of head and neck cancer, radiation therapy, or prolonged intubation are at particular risk. In one case, a fifty-year-old patient who had undergone laryngectomy and chemoradiation for throat cancer developed arterial bleeding from the esophagus during surgery, which was ultimately traced to the aberrant vessel and controlled with an endovascular stent.15PubMed. Massive upper gastrointestinal bleeding secondary to an esophago-arterial fistula (arteria lusoria) These cases are extremely rare, but they underscore why ARSA needs to be on the radar whenever a patient with known vascular anatomy faces esophageal procedures or prolonged intubation.
The Link to Down Syndrome and Prenatal Detection
ARSA has gained considerable attention in prenatal medicine because it shows up far more often in fetuses with Down syndrome than in those with typical chromosomes. A meta-analysis found that about 24% of fetuses with Down syndrome had an ARSA, compared to roughly 1% of chromosomally normal fetuses.16PubMed. Aberrant right subclavian artery in fetuses with Down syndrome: a systematic review and meta-analysis That difference has made ARSA a useful “soft marker” on prenatal ultrasound, meaning it is not diagnostic on its own but can raise the suspicion of a chromosomal abnormality when seen alongside other findings.
When an ARSA is found in isolation during a fetal ultrasound, with no other structural abnormalities, the likelihood that it signals a chromosomal problem is much lower. One study found zero cases of Down syndrome among fetuses with isolated ARSA who underwent genetic testing.17PubMed Central. Prenatal Identification of Aberrant Right Subclavian Artery in Isolation: The Need for Further Genetic Work-Up? A larger study from a referral center found that among isolated ARSA cases, clinically significant genetic findings on chromosomal microarray were present in about 2.5%, but the rate jumped considerably when ARSA appeared alongside cardiac or extra-cardiac anomalies.18Scientific Reports. Prenatal genetic analysis of fetal aberrant right subclavian artery with or without additional ultrasound anomalies in a third level referral center The practical takeaway for expectant parents is that an isolated ARSA on ultrasound is usually reassuring, but combined findings may prompt further genetic workup.
This prenatal context is distinct from the symptom question, but it is worth understanding because it is the most common way many people first hear about ARSA. Most fetuses diagnosed with isolated ARSA go on to be born healthy and never develop symptoms from the vessel itself.
How Symptoms Are Investigated
When a doctor suspects that an ARSA might be causing a patient’s swallowing difficulty or respiratory symptoms, the workup typically starts with imaging. A barium swallow X-ray can show a characteristic indentation on the back wall of the esophagus where the aberrant vessel crosses. CT angiography provides a detailed three-dimensional view of the vessel’s course, its size, and whether an aneurysm or Kommerell’s diverticulum is present. MRI can accomplish similar goals without radiation exposure. For patients with swallowing complaints, upper endoscopy may show an external pulsatile compression of the esophageal wall, which can be a striking finding if the clinician is not expecting it.
The challenge is that ARSA is often an incidental finding on imaging done for unrelated reasons. When a patient has vague swallowing difficulty and imaging happens to reveal an ARSA, deciding whether the artery is actually responsible for the symptoms or is an innocent bystander requires careful clinical judgment. Other causes of dysphagia, from motility disorders to reflux disease, are far more common.
Treatment Options When Symptoms Warrant It
Because the vast majority of people with ARSA never develop symptoms, no treatment is needed in most cases. For those with mild dysphagia, conservative management can be effective. Dietary modifications such as eating smaller bites, chewing thoroughly, choosing softer foods, and swallowing exercises have been reported to provide meaningful symptom improvement without any procedure.19Radiology Case Reports. Rare case of dysphagia lusoria due to an anomalous vertebral artery originating from the aortic arch
When symptoms are severe enough to affect quality of life or when complications like aneurysm or steal syndrome develop, surgery becomes the standard approach. The classic procedure involves dividing the aberrant vessel from the aorta and reconnecting it to the right common carotid artery, restoring normal blood flow to the right arm while removing the compressive structure. In published surgical series, this approach has relieved symptoms completely with low complication rates.20PubMed Central. Surgical approaches to the aberrant right subclavian artery More recently, hybrid techniques combining open cervical surgery with endovascular stent grafts have been used, particularly when the origin of the aberrant vessel from the aorta is difficult to reach or when a Kommerell’s diverticulum needs to be excluded.21Journal of Vascular Surgery Cases, Innovations and Techniques. Hybrid repair of aberrant right subclavian artery using open and endovascular techniques
A Surgical Consideration You Would Not Guess
One consequence of ARSA that affects surgeons rather than patients directly is the presence of a non-recurrent laryngeal nerve. Normally, the right recurrent laryngeal nerve loops under the right subclavian artery before heading back up to the voice box. When the subclavian artery arises abnormally from the aortic arch, the nerve has nothing to loop around and instead takes a direct path from the vagus nerve to the larynx. This altered anatomy matters enormously during thyroid and parathyroid surgery, because the recurrent laryngeal nerve runs in a predictable location that surgeons rely on to avoid damaging it. A non-recurrent nerve is in a completely different position, and inadvertent injury can cause hoarseness or vocal cord paralysis.12Journal of Anatomical Variation and Clinical Case Report. Aberrant Right Subclavian Artery: A Cadaveric Case Study with Anatomy Suggestive of Subclavian Steal Syndrome This is not a “symptom” in the traditional sense, but it is a real clinical risk that flows directly from the anatomy, and it is one reason surgeons increasingly check preoperative imaging for aortic arch variants before operating on the neck.