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A vascular ring, whether complete or incomplete, is a form of aortic arch malformation that can lead to innominate artery compression syndrome (IACS). Vascular rings are abnormalities of the aortic arch that encircle or compress the trachea and esophagus. The incidence of IACS is low, but it can have severe clinical consequences if not recognized and treated appropriately. The presentation of IACS can be quite variable but tends to manifest in the pediatric population. Some patients have intermittent mild respiratory symptoms (eg, dyspnea, wheezing, or cough). Others have recurrent respiratory infections and can often be misdiagnosed. Occasionally, patients present in severe respiratory distress; imaging or bronchoscopy makes the diagnosis fairly quickly. Surgical intervention should be considered in symptomatic patients, with the goal being to relieve tracheal compression. Those with mild symptoms can often be treated nonsurgically with aggressive airway clearance regimens and treatment of respiratory infections, with supplemental oxygen if necessary. This activity for healthcare professionals is designed to enhance the learner's competence in recognizing innominate artery compression syndrome, performing the recommended evaluation, and implementing an appropriate interprofessional management approach to improve patient outcomes. Objectives: Interpret the embryology of aortic arches in developing innominate artery compression syndrome. Assess patients with clinical features of innominate artery compression syndrome. Select the appropriate management strategy for patients with innominate artery compression syndrome. Collaborate with members of an interprofessional team to optimize the management of innominate artery compression syndrome. Access free multiple choice questions on this topic.

Innominate artery compression syndrome (IACS) is a rare illness due to a vascular ring. A vascular ring is an aortic arch malformation that causes trachea and esophagus compression. These rings can be complete or incomplete, depending on whether vascular tissue encircles the mediastinal structures. In IACS, the innominate artery compresses the trachea anteriorly and is, therefore, an incomplete ring.[1][2] The presentation of IACS can be quite variable but tends to manifest in the pediatric population. Some patients have intermittent mild respiratory symptoms (eg, dyspnea, wheezing, or cough). Others have recurrent respiratory infections and can often be misdiagnosed. Occasionally, patients present in severe respiratory distress; imaging or bronchoscopy makes the diagnosis fairly quickly.[3][4][5] Surgical intervention should be considered in symptomatic patients, with the goal being to relieve tracheal compression. Those with mild symptoms can often be treated nonsurgically with aggressive airway clearance regimens and treatment of respiratory infections, with supplemental oxygen if necessary.[6][7][8][9] The first successful surgical repair of a vascular ring was performed by Dr. Robert Gross at Boston Children’s Hospital. He initially identified a vascular ring during an autopsy, noting, “A ring of blood vessels was found encircling the intrathoracic portion of the esophagus and trachea....The pathologic findings once suggested that a division of some part of the vascular ring during life would have relieved the pressure on the constricted trachea and esophagus.” Based on this observation, Gross successfully applied this interpretation in a clinical setting by dividing a double aortic arch in a 1-year-old child who had persistent wheezing and recurrent hospitalizations due to severe upper respiratory tract infections. In 1953, Dr. Robert Gross summarized his surgical experience with aortic arch anomalies, and more than 70 years later, his recommendations remain relevant.[10]

IACS is categorized as a specific illness due to a vascular ring.[1] Vascular rings are anomalies of the aortic arch and brachiocephalic vessel branching pattern that cause esophagus and trachea compression.[2] They form due to variations during the embryonic development of the aortic arch system. In utero, 6 primitive aortic arches connect the aortic sac with the dorsal aortas. A double aortic arch system is formed initially, but 1 arch usually involutes and regresses. Typically, a left-sided aortic arch with the expected head and neck vessels is formed, with the right aortic arch regression. However, several possible configurations are possible. The final configuration of the aortic arch system is derived from multiple levels of the original primitive aortic arches. Aortic Sac The aortic sac is the first portion of the aorta to form, appearing as a dilated structure superior to the truncus arteriosus. The aortic sac then develops 2 horns, inevitably leading to important aortic structures. The right horn gives rise to the brachiocephalic artery. In contrast, the left horn combines with the stem of the aortic sac to form the portion of the aortic arch proximal to the brachiocephalic trunk. The aortic arches develop from the aortic sac and proceed into the pharyngeal arches. Aortic Arches

The aortic sac is the first portion of the aorta to form, appearing as a dilated structure superior to the truncus arteriosus. The aortic sac then develops 2 horns, inevitably leading to important aortic structures. The right horn gives rise to the brachiocephalic artery. In contrast, the left horn combines with the stem of the aortic sac to form the portion of the aortic arch proximal to the brachiocephalic trunk. The aortic arches develop from the aortic sac and proceed into the pharyngeal arches. Aortic Arches The first aortic arch regresses early, but a remnant forms a portion of the maxillary artery. The second aortic arch also regresses early, but a remnant forms portions of the hyoid and stapedial arteries. The third aortic arch contributes to forming the common carotid arteries bilaterally and the proximal internal carotid arteries bilaterally. The right side of the fourth arch contributes to the right proximal subclavian artery, and the left portion of the fourth arch gives rise to the medial portion of the aortic arch. The fifth aortic arch never forms or incompletely forms and regresses, while the right and left sides of the sixth aortic arch separate into ventral and dorsal segments. The ventral segments are responsible for the formation of the pulmonary arteries bilaterally. The left ventral arch also contributes to the formation of the pulmonary trunk. The right dorsal arch regresses. The left dorsal arch forms the ductus arteriosus, which later closes and is termed the ligamentum arteriosum. The aortic arches, pharyngeal arch arteries, and branchial arches develop from the aortic sac. A pair of branches (right and left) travel within each pharyngeal arch and end in the dorsal aorta. Initially, the arches arise in symmetrical pairs, but after remodeling, they become asymmetric, and several arches regress. All 6 pairs are not present simultaneously; they develop and regress at different stages.

The first aortic arch regresses early, but a remnant forms a portion of the maxillary artery. The second aortic arch also regresses early, but a remnant forms portions of the hyoid and stapedial arteries. The third aortic arch contributes to forming the common carotid arteries bilaterally and the proximal internal carotid arteries bilaterally. The right side of the fourth arch contributes to the right proximal subclavian artery, and the left portion of the fourth arch gives rise to the medial portion of the aortic arch. The fifth aortic arch never forms or incompletely forms and regresses, while the right and left sides of the sixth aortic arch separate into ventral and dorsal segments. The ventral segments are responsible for the formation of the pulmonary arteries bilaterally. The left ventral arch also contributes to the formation of the pulmonary trunk. The right dorsal arch regresses. The left dorsal arch forms the ductus arteriosus, which later closes and is termed the ligamentum arteriosum. The aortic arches, pharyngeal arch arteries, and branchial arches develop from the aortic sac. A pair of branches (right and left) travel within each pharyngeal arch and end in the dorsal aorta. Initially, the arches arise in symmetrical pairs, but after remodeling, they become asymmetric, and several arches regress. All 6 pairs are not present simultaneously; they develop and regress at different stages. The formation of different types of vascular rings depends on the persistence, regression, or involution of these arches, leading to varying degrees of tracheal and esophageal compression and a range of symptoms in patients. For instance, the persistence of the right fourth arch combined with the interruption of the left arch results in a right aortic arch with a left ligamentum arteriosum.[11] A vascular ring may form if this developmental process is disrupted with the persistence of any of these structures, anomalous origins, or certain variants of brachiocephalic branching patterns.[12] According to recent research, the most frequently observed complete vascular ring is the right aortic arch with an aberrant left subclavian artery, followed by the double aortic arch. Among incomplete vascular rings, innominate artery (IA) compression is found in 3% to 20% of cases, with the left pulmonary artery sling being another notable cause.[13] Pulmonary artery sling is where the origin of the left pulmonary artery arises from the right pulmonary artery instead of the main pulmonary artery. This compresses the distal trachea and right mainstem bronchus posterior to the trachea and anterior to the esophagus toward supplying the left lung, known as a “vascular sling.”

The formation of different types of vascular rings depends on the persistence, regression, or involution of these arches, leading to varying degrees of tracheal and esophageal compression and a range of symptoms in patients. For instance, the persistence of the right fourth arch combined with the interruption of the left arch results in a right aortic arch with a left ligamentum arteriosum.[11] A vascular ring may form if this developmental process is disrupted with the persistence of any of these structures, anomalous origins, or certain variants of brachiocephalic branching patterns.[12] According to recent research, the most frequently observed complete vascular ring is the right aortic arch with an aberrant left subclavian artery, followed by the double aortic arch. Among incomplete vascular rings, innominate artery (IA) compression is found in 3% to 20% of cases, with the left pulmonary artery sling being another notable cause.[13] Pulmonary artery sling is where the origin of the left pulmonary artery arises from the right pulmonary artery instead of the main pulmonary artery. This compresses the distal trachea and right mainstem bronchus posterior to the trachea and anterior to the esophagus toward supplying the left lung, known as a “vascular sling.” Vascular rings can be subdivided into the following 4 main groups, classified as complete or incomplete: Complete Right aortic arch with an aberrant left subclavian artery Double aortic arch Incomplete Innominate artery compression syndrome Pulmonary artery sling [14]

The formation of different types of vascular rings depends on the persistence, regression, or involution of these arches, leading to varying degrees of tracheal and esophageal compression and a range of symptoms in patients. For instance, the persistence of the right fourth arch combined with the interruption of the left arch results in a right aortic arch with a left ligamentum arteriosum.[11] A vascular ring may form if this developmental process is disrupted with the persistence of any of these structures, anomalous origins, or certain variants of brachiocephalic branching patterns.[12] According to recent research, the most frequently observed complete vascular ring is the right aortic arch with an aberrant left subclavian artery, followed by the double aortic arch. Among incomplete vascular rings, innominate artery (IA) compression is found in 3% to 20% of cases, with the left pulmonary artery sling being another notable cause.[13] Pulmonary artery sling is where the origin of the left pulmonary artery arises from the right pulmonary artery instead of the main pulmonary artery. This compresses the distal trachea and right mainstem bronchus posterior to the trachea and anterior to the esophagus toward supplying the left lung, known as a “vascular sling.” Vascular rings can be subdivided into the following 4 main groups, classified as complete or incomplete: Complete Right aortic arch with an aberrant left subclavian artery Double aortic arch Incomplete Innominate artery compression syndrome Pulmonary artery sling [14] Complete vascular rings have vascular tissue encircling the trachea and esophagus, while incomplete vascular rings do not. IACS is due to an incomplete ring defined by compression of the trachea anteriorly by the innominate artery of at least 75% to 80%.[1][2] The true anatomy of the innominate artery and whether this syndrome should be considered an aortic arch “malformation” is debated.[15] Historically, the abnormal distal and posterior takeoff of the innominate artery from the aortic arch was thought to cause this compression. The compression occurs as the artery courses from the left chest across the midline to the right arm.[6] Many studies have examined the anatomy of the aortic arch in infants and children and found that the innominate artery originates in front of or to the left of the trachea in the vast majority. Yet, only a minority of these patients were symptomatic enough to require surgical intervention.[15][16][17] In addition, studies have observed that the takeoff of the innominate artery shifts to the right in adulthood, which explains why IACS is rarely diagnosed beyond infancy.[18] Others suspect IACS may result from crowding the anterior mediastinum or associated with primary tracheomalacia.[19][20][7] The cause is likely multifactorial and not solely because of an abnormal takeoff of the innominate artery from the aortic arch.[21]

Innominate artery compression syndrome is the most common cause of airway compression by a vascular structure.[22] The true incidence of this syndrome is unknown but has been reported to be overall low at 3%.[3] Evidence of anterior tracheal compression on lateral chest radiographs may occur in up to 30% of the general population and up to 71% of those patients with congenital heart disease.[15] However, only a small portion of these patients need surgical intervention.[23][24] A higher incidence of IACS in patients with a history of esophageal atresia or tracheoesophageal fistula repair and in those with Morquio A syndrome has also been observed.[25][26][27] Finally, the syndrome has also been observed in patients with congenital diaphragmatic hernia, which is thought to be secondary to the mediastinal shift towards the hypoplastic left lung following hernia repair.[28]

A thorough history and physical are required to diagnose IACS accurately. The clinical presentation overlaps with many other airway pathologies, leading to frequent misdiagnoses.[3] Patients with IACS will present with a variety of respiratory symptoms, including dyspnea, wheezing, stridor, cough, recurrent respiratory infections, and respiratory distress. The most concerning symptom is reflex apnea. Fearon et al coined the term “reflex respiratory arrest initiated by irritation of the area of compression of the trachea.” A bolus of food moving through the esophagus near the area of tracheal compression or an accumulation of secretions may trigger the reflex. Patients will suffer a period of apnea with cyanosis but tend to recover fully within a few minutes.[5] These symptoms are suspected to be secondary not only to the external compression of the trachea but also to ciliary immotility and inability to clear secretions.[29] A majority of patients will present with more than 1 respiratory symptom. Studies have found that up to 60% to 70% of patients will have more than 3 presenting symptoms. Typically, symptoms begin within the first year of life.[3][4] This is likely related to the tracheal rings being softer and more collapsible in infancy.[8] Some studies, however, include a cohort of patients with a delayed presentation and diagnosis into adolescence.[30] As one would suspect, a higher proportion of severe symptoms (eg, reflex apnea and stridor) are found in younger patients.[3] A few reports have also described a presentation of IACS with opisthotonos (neck muscle spasm causing backward arching of the neck), which resolved with treatment of the IACS.[31] The aberrant right subclavian artery is a variant anatomical structure found in approximately 1% of the population. Around 60% of these cases feature a Kommerell diverticulum, a bulge at the origin of the aberrant subclavian artery—whether right or left—in a left-sided or right-sided aortic arch, respectively. While most patients with this condition are asymptomatic, some may experience symptoms such as difficulty swallowing (dysphagia), shortness of breath (dyspnea), or chest pain. The symptoms often depend on the aneurysm size and compression, whether retro-esophageal, between the esophagus and trachea, or pre-tracheal.[32]

An extensive assessment is required to diagnose IACS since this is a rare syndrome with considerable overlap with other, more common differential diagnoses. The evaluation may include a combination of chest radiography (CXR), bronchoscopy, esophagoscopy, angiography, computational tomography (CT), magnetic resonance imaging (MRI), and pulmonary function testing (PFT). Innominate artery compression syndrome can be noted on lateral CXRs as the anterior indentation of the trachea. This modality may be a good initial screening tool for diagnosing IACS; however, CXR is not always accurate in identifying the pathology in symptomatic patients. Studies have found that some patients with evidence of severe narrowing demonstrated on bronchoscopy may initially have a normal appearance on CXR.[17] Therefore, flexible bronchoscopy is the gold standard for diagnosing IACS due to a vascular ring. Flexible bronchoscopy is often performed with inhaled anesthetic while the patient breathes spontaneously.[18] In patients with IACS, the trachea is compressed anteriorly with an asymmetric compression slope towards the patient’s right. This leaves a small lumen on the leftward aspect of the trachea. The collapse is almost always in the lower two-thirds of the trachea, about 1 to 2 cm above the carina. An additional finding during the procedure that supports the diagnosis of IACS is the loss of the right radial arterial pulse with anterior compression by the bronchoscope at the site of obstruction.[9] However, the findings obtained during bronchoscopy remain highly subjective and depend on the plane of anesthesia and the bronchoscopic technique.[33][34]

Innominate artery compression syndrome can be noted on lateral CXRs as the anterior indentation of the trachea. This modality may be a good initial screening tool for diagnosing IACS; however, CXR is not always accurate in identifying the pathology in symptomatic patients. Studies have found that some patients with evidence of severe narrowing demonstrated on bronchoscopy may initially have a normal appearance on CXR.[17] Therefore, flexible bronchoscopy is the gold standard for diagnosing IACS due to a vascular ring. Flexible bronchoscopy is often performed with inhaled anesthetic while the patient breathes spontaneously.[18] In patients with IACS, the trachea is compressed anteriorly with an asymmetric compression slope towards the patient’s right. This leaves a small lumen on the leftward aspect of the trachea. The collapse is almost always in the lower two-thirds of the trachea, about 1 to 2 cm above the carina. An additional finding during the procedure that supports the diagnosis of IACS is the loss of the right radial arterial pulse with anterior compression by the bronchoscope at the site of obstruction.[9] However, the findings obtained during bronchoscopy remain highly subjective and depend on the plane of anesthesia and the bronchoscopic technique.[33][34] During a tracheobronchoscopy, a rigid ventilating bronchoscope is initially inserted while the patient breathes quietly, revealing baseline compressions, cartilage abnormalities, and granulation tissue. In the second phase, anesthesia depth is reduced to induce coughing, highlighting the dynamic airway collapse characteristic of tracheobronchomalacia. The final phase involves inflating the airway with positive pressure to identify fixed tracheobronchial compressions, tracheoesophageal fistulae, tracheal diverticula, or abnormal branching patterns.[18] Most surgeons use dynamic narrowing of the airway lumen of >50% during forced exhalation or coughing as a diagnostic benchmark. In children with symptomatic TM/TBM, >70% of airway collapse in 1 or more regions is common during forced exhalation or coughing. Those with recurrent pulmonary infections often experience complete collapse in >1 region, leading to impaired mucus clearance from the affected distal airway.[35] Esophagoscopy and barium esophagograms may also rule out other causes for the presenting symptoms. External compression of the esophagus may lead to suspicion that another type of vascular ring is involved, as IACS does not cause compression of the esophagus. In addition, gastroesophageal reflux disease (GERD) can sometimes manifest with respiratory symptoms.[36]

During a tracheobronchoscopy, a rigid ventilating bronchoscope is initially inserted while the patient breathes quietly, revealing baseline compressions, cartilage abnormalities, and granulation tissue. In the second phase, anesthesia depth is reduced to induce coughing, highlighting the dynamic airway collapse characteristic of tracheobronchomalacia. The final phase involves inflating the airway with positive pressure to identify fixed tracheobronchial compressions, tracheoesophageal fistulae, tracheal diverticula, or abnormal branching patterns.[18] Most surgeons use dynamic narrowing of the airway lumen of >50% during forced exhalation or coughing as a diagnostic benchmark. In children with symptomatic TM/TBM, >70% of airway collapse in 1 or more regions is common during forced exhalation or coughing. Those with recurrent pulmonary infections often experience complete collapse in >1 region, leading to impaired mucus clearance from the affected distal airway.[35] Esophagoscopy and barium esophagograms may also rule out other causes for the presenting symptoms. External compression of the esophagus may lead to suspicion that another type of vascular ring is involved, as IACS does not cause compression of the esophagus. In addition, gastroesophageal reflux disease (GERD) can sometimes manifest with respiratory symptoms.[36] Historically, angiography was used to evaluate the anatomy of the aortic arch, its branches, and how they may relate to surrounding structures. More recently, CT and MRI have replaced invasive angiography and have become helpful adjuncts in diagnosing IACS.[37][38][39] These imaging modalities offer a more detailed look at the relationship of the aortic arch branches, the trachea, and the surrounding mediastinal structures. There is some concern, however, that CT and MRI may underestimate the degree of tracheal compression secondary to stenting of the airway by an endotracheal tube, the use of positive pressure ventilation, and variations in the respiratory phase throughout the scan.[4] However, the growing use of controlled-ventilation CT scans, especially in infants, may help to mitigate some of this concern.[40]

Historically, angiography was used to evaluate the anatomy of the aortic arch, its branches, and how they may relate to surrounding structures. More recently, CT and MRI have replaced invasive angiography and have become helpful adjuncts in diagnosing IACS.[37][38][39] These imaging modalities offer a more detailed look at the relationship of the aortic arch branches, the trachea, and the surrounding mediastinal structures. There is some concern, however, that CT and MRI may underestimate the degree of tracheal compression secondary to stenting of the airway by an endotracheal tube, the use of positive pressure ventilation, and variations in the respiratory phase throughout the scan.[4] However, the growing use of controlled-ventilation CT scans, especially in infants, may help to mitigate some of this concern.[40] Pulmonary function tests have also been used in some patients to confirm airway obstruction secondary to IACS and to evaluate the degree of severity.[29] This test is usually performed in older children and adolescents who can fully participate in the exam. However, specialized infant PFTs have been recently developed and used in diagnosing IACS.[41] The test is often performed both before and after exercise.[30] The flow and volume curve is characterized by an initial drop immediately following the peak expiratory flow, suggesting a temporary tracheal obstruction during the initial phase of forced expiration.[3] An echocardiogram should also be performed in all patients, as up to 12% of patients with vascular rings will also have some form of congenital heart disease.[42]

The management of IACS is largely dependent on the degree of symptoms. Given the differing rates of persistent symptoms, some experts recommend more complex initial interventions, believing these may offer the best chance of symptom relief. Nevertheless, 9% of patients will still need a reoperation to manage their symptoms further.[43] Surgical intervention is indicated for those with severe respiratory symptoms (ie, reflex apnea and stridor). Whereas those with mild symptoms can often be treated nonsurgically with aggressive airway clearance regimens and treatment of respiratory infections, with supplemental oxygen if necessary.[30] The degree of symptoms often correlates with the degree of tracheal compression, with the most symptomatic having at least 70% or greater tracheal compression.[3] In patients who have failed aggressive medical management or those with recurrent respiratory infections, surgery may be considered for those with significant compression of the trachea by the innominate artery. Other relative indications for surgery include those with concomitant subglottic stenosis or tracheomalacia, a history of tracheoesophageal fistula repair with recurrent respiratory distress, exercise intolerance, recurrent cough, or patients with a history of asthma or cystic fibrosis.[24][34] An Italian surgical team has produced an algorithm for conservative vs. surgical therapy for IACS. Conservative treatment is generally recommended for children with mild symptoms, no complications, infrequent bacterial exacerbations, extended symptom-free periods, less than  50% tracheal compression, and progressively improving symptoms. In contrast, surgical therapy is advised for those with severe symptoms, complications, frequent exacerbations (occurring monthly), short symptom-free periods, great than 50% tracheal compression, and worsening symptoms.[44]

An Italian surgical team has produced an algorithm for conservative vs. surgical therapy for IACS. Conservative treatment is generally recommended for children with mild symptoms, no complications, infrequent bacterial exacerbations, extended symptom-free periods, less than  50% tracheal compression, and progressively improving symptoms. In contrast, surgical therapy is advised for those with severe symptoms, complications, frequent exacerbations (occurring monthly), short symptom-free periods, great than 50% tracheal compression, and worsening symptoms.[44] The most commonly used surgical procedure to treat IACS involves the suspension of the aortic arch, innominate artery, or both from the posterior sternum to lift the vascular structures off the anterior trachea.[6][7][8][9] Depending on which vessels are being suspended, the procedure is described as an aortopexy (aorta only), an aortoinnominopexy (aorta and innominate artery), or an innominate arteriopexy (innominate artery only). The approach for these procedures historically has been through a right or left thoracotomy, but approaches via a median sternotomy and an upper midline hemisternotomy have also been described.[45][46] During the thoracotomy, a portion of the thymus is removed. Then, several heavy, nonabsorbable sutures are placed through the adventitia or pericardium surrounding the vasculature and through the posterior wall of the sternum. These sutures pull the aorta and/or innominate artery anteriorly away from the trachea. Because no dissection was performed between the artery and the trachea, in theory, this also pulls the anterior wall forward. Confirmation of this improvement in tracheal obstruction should be confirmed after the procedure with bronchoscopy. Other studies have described reimplanting the innominate artery. However, this involves using a median sternotomy approach, heparinization of the patient, and clamping the aorta and innominate artery.[47] While the proponents of this method claim it reduces the need for reintervention, others argue that the risks outweigh the benefits.[48] Hemisternotomy may be a superior technique for ascending aortopexy in cases of innominate artery compression syndrome (IACS), achieving complete symptom resolution in 78% of patients at one center. This approach has several advantages, including:

During the thoracotomy, a portion of the thymus is removed. Then, several heavy, nonabsorbable sutures are placed through the adventitia or pericardium surrounding the vasculature and through the posterior wall of the sternum. These sutures pull the aorta and/or innominate artery anteriorly away from the trachea. Because no dissection was performed between the artery and the trachea, in theory, this also pulls the anterior wall forward. Confirmation of this improvement in tracheal obstruction should be confirmed after the procedure with bronchoscopy. Other studies have described reimplanting the innominate artery. However, this involves using a median sternotomy approach, heparinization of the patient, and clamping the aorta and innominate artery.[47] While the proponents of this method claim it reduces the need for reintervention, others argue that the risks outweigh the benefits.[48] Hemisternotomy may be a superior technique for ascending aortopexy in cases of innominate artery compression syndrome (IACS), achieving complete symptom resolution in 78% of patients at one center. This approach has several advantages, including: Visualization and safety: A partial upper median sternotomy allows for a complete thymectomy, enhancing the visualization of the bilateral phrenic nerves and reducing the risk of nerve injury. A thorough thymectomy is crucial as it increases the anteroposterior dimension in the upper mediastinum, facilitating greater movement of the innominate artery towards the sternum and reducing the distracting force on the trachea. Using an anterior thoracotomy approach may not allow sufficient external examination of the trachea, potentially missing the accurate diagnosis and leading to the patient undergoing a tracheostomy due to the less effective result from an aortopexy.[45] Surgical flexibility: This technique increases the likelihood of achieving an excellent anatomical outcome, defined as ≤20% residual stenosis. If this stenosis is not attained, it suggests investigating alternative causes, such as intrinsic tracheal pathology. Unlike a thoracotomy, a partial sternotomy can be easily converted to a full sternotomy, allowing for comprehensive exploration of the anterior trachea between the superior vena cava and the aorta.

Surgical flexibility: This technique increases the likelihood of achieving an excellent anatomical outcome, defined as ≤20% residual stenosis. If this stenosis is not attained, it suggests investigating alternative causes, such as intrinsic tracheal pathology. Unlike a thoracotomy, a partial sternotomy can be easily converted to a full sternotomy, allowing for comprehensive exploration of the anterior trachea between the superior vena cava and the aorta. Anatomical clarity: The partial upper median sternotomy better appreciates the innominate artery's anatomy. An alternative procedure for treating IACS is reimplanting the innominate artery, which can be performed off-pump, relocating the artery approximately 1 cm proximally on the greater curvature of the aorta to the right of the trachea. This reimplantation immediately alleviates compression without long-term adverse effects.[49] Dividing the innominate artery has also been described but has recently fallen out of favor.[17][24] Occasionally, patients will have intrinsic airway disease in addition to the vascular compression and will require some form of tracheobronchoplasty in addition to surgical intervention on the vasculature to relieve airway compression.[45][50] Rarely do patients with thoracic cage abnormalities have IACS secondary to their disease process. These patients often require a more involved reconstruction to address the vascular compression of the airway.[18][51][52]

The differential diagnosis of IACS consists of a range of upper and lower airway diseases along with some cardiovascular and upper gastrointestinal pathologies, including: Airway Laryngomalacia Tracheomalacia Tracheal stenosis Vocal cord paralysis Reactive airway disease Sleep apnea Cardiovascular Vascular rings Cardiomegaly Gastrointestinal Gastroesophageal reflux Laryngopharyngeal reflux [22][3][53]

Most patients report subjective improvement in their symptoms following surgical intervention for IACS. Multiple studies have reported relief of symptoms in up to 90% of patients undergoing either the aortopexy or the reimplantation methods. The incomplete resolution of symptoms is often secondary to concomitant pathologies (eg, subglottic stenosis, laryngomalacia, and tracheoesophageal fistula).[17][54] Gardella et al examined long-term symptomatic improvement in their cohort of patients who underwent aortopexy for IACS. They found only 1 out of the 16 patients in their study had a recurrence of symptoms that impacted lifestyle, while the remainder were either completely asymptomatic or intermittently symptomatic.[3]

The overall complication rate of surgical repair for IACS is low. The most common complication after IACS repair is the need for surgical revision. This rate is at most 5% for both aortopexy and innominate artery reimplantation methods.[9][47][48] The rate of other surgical complications ranges from 0% to 25% in the literature, with more recent data suggesting a rate closer to 2%.[3][9][55] These complications include wound infection, prolonged intubation, pericardial effusion, and post-cardiotomy syndrome.[3][55]

Innominate artery compression syndrome is a rare form of vascular ring. Regardless, patients with respiratory symptoms suspicious of IACS should be counseled on needing a thorough evaluation. If IACS is identified and surgery is indicated, patients and families should understand the risks and benefits of the procedure as well as the favorable prognosis and long-term outcomes, including that symptoms may persist despite undergoing surgery. If airway compression by the innominate artery is identified but does not meet the threshold for intervention, patients should receive education on what signs and symptoms would be concerning for worsening airway obstruction and when to seek medical care. Finally, they should be reassured that infants and children who have IACS but do not need surgery will typically outgrow the symptoms and have an average life expectancy.

While the incidence of IACS is low, patients with significant compression of their airway have a high degree of morbidity and mortality. Identifying, evaluating, and treating these patients requires collaboration between multiple medical specialties. Overall, surgical treatment patients do well with improved symptoms, emphasizing the importance of clinically expert interprofessional care. Pediatricians, advanced practice clinicians, emergency medicine physicians, otolaryngologists, pulmonologists, cardiothoracic surgeons, critical care physicians, nurses, pharmacists, and other healthcare clinicians are involved in the care of these patients. They should possess the clinical skills and expertise necessary to manage their care. This includes identifying patients at risk for IACS based on presentation, coordinating their evaluation, having the ability to interpret the findings correctly, and, if necessary, consulting the appropriate surgical teams. Each care team member provides unique skills to facilitate effective interprofessional patient care.