Vascular rings

Abstract

The term vascular ring refers to congenital vascular anomalies of the aortic arch system that compress the esophagus and trachea, causing symptoms related to those two structures. The most common vascular rings are double aortic arch and right aortic arch with left ligamentum. Pulmonary artery sling is rare and these patients need to be carefully evaluated for frequently associated tracheal stenosis. Another cause of tracheal compression occurring only in infants is the innominate artery compression syndrome. In the current era, the diagnosis of a vascular ring is best established by CT imaging that can accurately delineate the anatomy of the vascular ring and associated tracheal pathology. For patients with a right aortic arch there recently has been an increased recognition of a structure called a Kommerell diverticulum which may require resection and transfer of the left subclavian artery to the left carotid artery. A very rare vascular ring is the circumflex aorta that is now treated with the aortic uncrossing operation. Patients with vascular rings should all have an echocardiogram because of the incidence of associated congenital heart disease. We also recommend bronchoscopy to assess for additional tracheal pathology and provide an assessment of the degree of tracheomalacia and bronchomalacia. The outcomes of surgical intervention are excellent and most patients have complete resolution of symptoms over a period of time.

Introduction

The first surgical repair of a vascular ring was performed by Dr. Robert Gross¹ from Boston Children’s Hospital. He first described a vascular ring diagnosed at autopsy: “A ring of blood vessels was found encircling the intrathoracic portion of the esophagus and trachea…. The pathologic findings at 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.” Gross made this observation and then applied the interpretation clinically to successfully divide a double aortic arch in a 1-year-old child with persistent wheezing and recurrent hospital admissions for serious upper respiratory tract infections.

The term vascular ring is now loosely used to refer to all congenital vascular anomalies of the aortic arch system that cause compression of the trachea and/or esophagus. The symptoms relative to these two structures are primarily noisy breathing, cough, and dysphagia. An example of a CT image of a child with a double aortic arch is shown in Figure 1.

Gross¹ was also the first to describe the other type of commonly seen true vascular ring, which is a right aortic arch with an aberrant or retroesophageal left subclavian artery and a left ligamentum arteriosum. It is in this group that we have recently recognized that the Kommerell diverticulum that serves as the source of blood flow to the left subclavian artery, may be an independent contributor to the compression of the trachea and esophagus and require removal.

At our institution Dr. Willis J. Potts² reported the first successful vascular ring repair (double aortic arch) in 1948. Potts also was the first surgeon to report successful repair of the anomaly now known as pulmonary artery sling.³ This is a rare vascular anomaly where the left pulmonary artery originates from the right pulmonary artery. The left pulmonary artery encircles the distal trachea as it travels to the left lung. This compresses the distal trachea and right mainstem bronchus. The classification scheme that we have used at Ann & Robert H. Lurie Children’s Hospital of Chicago for vascular rings is that endorsed by the Society of Thoracic Surgeons’ Congenital Nomenclature and Database Project.⁴ The surgical experience with vascular rings at Lurie Children’s is illustrated in Table 1 (1947–2015; DAA; RAA; PAS). This article will review the clinical presentation and diagnosis, embryology, indications for surgery, surgical techniques for the different vascular rings, and the outcomes of surgical intervention.