Imaging strategies for vascular rings

Vascular Rings of the Thoracic Aorta in Adults

Vascular rings have been well documented to cause respiratory and gastrointestinal symptoms in infants and children. Few reports document symptomatic vascular rings in adults, and most have emphasized dysphagia as the predominant symptom. We present the case of a 36-year-old white male with a double aortic arch and progressive dyspnea on exertion. This led us to review previous reports of vascular rings in adults. Criteria for review consisted of anatomically complete vascular rings of the aortic arch in adults age 18 years or older. We identified 25 prior cases for review and included our recent patient. The most common vascular ring anomalies in our review of adults is double aortic arch (n = 12; 46%) followed by right aortic arch with aberrant left subclavian artery and ligamentum arteriosum (n = 8; 30%). Of 24 patients (66%), 16 were symptomatic. Reported symptoms involving the respiratory tract (n = 10 of 24; 42%) included dyspnea on exertion (n = 5), bronchitis (n = 2), recurrent pneumonia, stridor, and unspecified respiratory ailment (n = 1 each). Dysphagia was less common, occurring in eight patients (33%). Previously proposed mechanisms for respiratory tract symptoms include tracheomalacia, static or dynamic compression of the airways, intravascular volume infusion, and aspiration. We also propose exercise-induced dilatation of the aortic arch and age-dependent changes in thoracic compliance as potential mechanisms of dyspnea.

Pulmonary artery sling: reimplantation versus antetracheal translocation

BACKGROUND

We compared two repair techniques for pulmonary artery sling. The first comprised detachment of the aberrant left pulmonary artery from the right pulmonary artery and its implantation into the main pulmonary artery, and the second, translocation of the left pulmonary artery anterior to the trachea (without implanting it into the main pulmonary artery), resection of tracheal stenosis, and end-to-end reconstruction of the trachea.

METHODS

Five symptomatic infants (3 boys and 2 girls; median age 5 months; range, 3 weeks to 11 months) with pulmonary artery sling were operated on through a median sternotomy with aid of cardiopulmonary bypass. In 3 patients, the left pulmonary artery was transected from the right pulmonary artery and implanted into the main pulmonary artery. In addition, the anterior trachea was augmented with a pericardial patch (n = 2). In the remaining 2 patients, associated tracheal stenosis was resected, the left pulmonary artery was translocated anterior to the trachea, and the trachea was reconstructed.

RESULTS

All 5 infants survived the operation. The 3 patients in whom the left pulmonary artery was implanted into the main pulmonary artery had an uncomplicated postoperative course. All 3 patients, at a follow-up of 10 months to 7.9 years, were free of symptoms; the left pulmonary artery was documented to be widely patent. The remaining 2 patients in whom the left pulmonary artery was translocated anterior to the trachea could not be extubated. In both patients the distal trachea was compressed anteriorly by the left pulmonary artery. One of these patients died at 1 week postoperatively secondary to tracheal dehiscence. In the other patient, the left pulmonary artery was implanted into the main pulmonary artery with good result; at a follow-up of 3.9 years, mild residual stridor has persisted.

CONCLUSIONS

In pulmonary artery sling, implantation of the aberrant left pulmonary artery into the main pulmonary artery, if necessary combined with anterior tracheoplasty, reliably eliminates tracheal and esophageal compression and maintains antegrade flow into the left pulmonary artery. Translocation of the left pulmonary artery anterior to the trachea without implanting it into the main pulmonary artery is not favored because that might result in anterior compression of the trachea. In addition, we are concerned about growth of the circumferential tracheal anastomosis in neonates and infants.

Surgical treatment of vascular ring including right cervical aortic arch

Cervical aortic arch is a developmental entity consisting of persistence of the right or left third branchial arch and regression of the fourth branchial arches. In most cases, the aorta is redundant and crosses behind the esophagus to the opposite side. In the presence of an aberrant subclavian artery contralateral to the side of the aortic arch and a ligamentum arteriosum, a vascular ring is formed around the trachea and esophagus. Two young patients with right-sided cervical aortic arch, aberrant left subclavian artery, and ligamentum arteriosum presented with dysphagia and exertional dyspnea. In one patient, through a left thoracotomy, the ligamentum arteriosum was divided, and the trachea and esophagus were dissected thoroughly above and below the level of the ring. In addition, the aberrant left subclavian artery was divided at its origin from a large diverticulum and implanted into the left common carotid artery; the aortic diverticulum was resected. In the other patient, who had associated 22q11 chromosomal deletion, in addition to left-sided compression of the trachea and esophagus, there was additional marked compression of the right anterolateral trachea by the redundant ascending aorta. Through a median sternotomy, the ligamentum arteriosum was divided, and the trachea and esophagus were widely mobilized; an additional aortopexy of the ascending aorta to the right of the sternum resulted in the absence of tracheal compression. The cases of the two reported patients illustrate the clinical variability of vascular ring, including a right cervical aortic arch and the consequently versatile surgical approach that is needed to successfully address this combination of vascular anomalies.

Vascular anomalies causing symptomatic tracheobronchial compression

OBJECTIVES/HYPOTHESIS

To review the clinical presentation and diagnostic evaluation of patients with symptomatic congenital vascular anomalies causing tracheobronchial compression and to establish the short- and long-term results of surgical intervention with respect to postoperative complications, persistent symptoms, and ventilator and tracheostomy dependence.

STUDY DESIGN

Retrospective review.

METHODS

Chart review and telephone follow-up.

RESULTS

Between 1987 and 1996, 35 children underwent surgical intervention to relieve symptomatic tracheobronchial compression resulting from a congenital vascular anomaly. Historically, the onset of symptoms occurs within the first months of life; however, only 12 (34%) of patients were diagnosed by 6 months of age and 13 (37%) were diagnosed at greater than 1 year of age. Excluding anomalous innominate artery, chest radiography or barium swallow was suggestive of a congenital vascular anomaly in 30 (94%) of the patients. Magnetic resonance imaging correctly delineated the anatomy of the vascular anomaly in 29 patients. Bronchoscopy was diagnostic in all three patients with anomalous innominate arteries causing tracheal compression. Postoperative follow-up was obtained in 32 (91%) of patients; 25 (78%) of these were asymptomatic at the time of their most recent examination. The remaining patients had persistent stridor, recurrent respiratory tract infections, and/or chronic cough. In all three patients who underwent postoperative bronchoscopy for persistent symptoms, tracheomalacia was demonstrated in the region of previous compression.

CONCLUSIONS

Tracheobronchial compression from congenital vascular anomalies is a rare but treatable cause of respiratory symptoms. Early diagnosis requires a prompt, thorough clinical and radiologic evaluation. Surgery affords excellent long-term resolution of symptoms.

Esophageal rings, webs, and diverticula

Rings, webs, and diverticula are among the most common anatomic anomalies of the esophagus. Although these structural lesions are often asymptomatic, patients can develop significant problems with dysphagia, regurgitation, and aspiration. This article discusses the epidemiology, pathogenesis, diagnosis, and therapy of esophageal rings, webs, and diverticula with emphasis on the clinical, diagnostic, and therapeutic strategies involved in caring for patients with these conditions.

Successful surgical treatment of an Edwards type IIIB right aortic arch aneurysm: report of a case

A true aneurysm of the right aortic arch which accompanies various branching characteristics is very rare. We report herein the successful surgical treatment of an elderly patient found to have an Edwards type IIIB right aortic arch aneurysm encircling and compressing the trachea. The complete right aortic arch and right subclavian artery were reconstructed through the inside of the aneurysm using selective cerebral perfusion. The patient recovered well, with no residual neurologic deficit and with resolution of the dyspnoic attacks he had suffered preoperatively.

Cardiac MR imaging in congenital heart disease

Magnetic resonance imaging is a unique and insightful tool for the assessment of structure and function in congenital heart disease. For anatomic assessment, the large field of view, lack of limitation by patient size, and ability to create three-dimensional surface displays from routine imaging acquisitions offer several advantages over other modalities. The ability of magnetic resonance imaging to assess the volume and mass of bizarre ventricular shapes accurately and myocardial tissue and blood tagging as well as phase encoded velocity mapping has enhanced research in pediatric cardiology. Newer techniques, such as oxygen-sensitive magnetic resonance imaging and echo-planar magnetic resonance imaging, promise even further advances in research and in clinical applications.

A new diagnostic approach to vascular rings and pulmonary slings: the role of MRI

The conventional diagnostic work-up of a patient suspected of having a vascular cause for stridor, or dysphagia, includes esophagography and bronchoscopy to delineate the abnormal structure without imaging the structure itself. Cine-angiography is regarded as the golden standard, but is not routinely performed. Magnetic resonance imaging (MRI) is non-invasive and has the important advantage over cine-angiography of depicting all structures in the field of view. Color Doppler echocardiography depicts the great vessels, but not the esophagus and trachea. In 14 patients with obstructive symptoms and in four patients without obstructive symptoms MRI successfully imaged the abnormal structure, as was the case in two symptomatic patients using computer tomography. In this series, the findings were confirmed at surgery or by cine-angiography.

CONCLUSION

we suggest that in patients suspected of having a vascular cause for stridor or dysphagia, MRI should be performed. If there is need for a screening procedure, color Doppler echocardiography should be used and if that is equivocal or non-conclusive, esophagography and bronchoscopy should be used. If MRI is difficult to interpret, it should be augmented by magnetic resonance angiography before considering cine-angiography.

An adult case of pulmonary sling with complete tracheal ring

Pulmonary sling is a rare congenital condition in which the left pulmonary artery arises from the right pulmonary artery forming a sling around the trachea causing tracheal compression. Many cases are associated with cardiovascular and tracheo-bronchial anomalies. When combined with complete tracheal ring, it is called "ring-sling complex". The average onset of symptoms is 2 months and about half have symptoms from birth. The anomaly, if not corrected, can be fatal within the first year of life. In an adult, it is most often asymptomatic and usually found incidentally. We report an adult case who was diagnosed as pulmonary sling with complete tracheal ring by CT and bronchoscopy along with a literature review.

Video-assisted thoracoscopic surgery for congenital heart disease

Video-assisted endoscopic techniques have reduced operative trauma in adult thoracic and general surgery, but applications in children with congenital heart disease have been limited. We report the development of video-assisted thoracic surgery procedures for neonates and infants with cardiovascular disease. Endoscopic instruments and techniques for pediatric cardiovascular procedures were designed and tested in the animal laboratory. Forty-eight operations were subsequently performed in 46 pediatric patients ranging in age from 2 hours to 14 years (median 9 months), weighing from 575 grams to 54 kg (median 8.5 kg). Clinical applications included seven different surgical procedures: patent ductus arteriosus interruption in infants (n = 26) and premature neonates (n = 5), vascular ring division (n = 8), pericardial drainage and resection (n = 3), arterial and venous collateral interruption (n = 2), thoracic duct ligation (n = 2), epicardial pacemaker lead insertion (n = 1), and diagnostic thoracoscopy (n = 1). There was no operative mortality. Technical success, defined as a video-assisted procedure completed without incising chest wall muscle or spreading the ribs, was achieved in 39 of 48 procedures (82%), with thoracotomy required to complete nine procedures. Most patients (22/25, 88%) undergoing elective ductus ligation were extubated in the operating room and discharged from the hospital within 48 hours of the operation. Eight of the last 10 patients having ductus ligation were discharged on the first postoperative day. Residual ductal flow was assessed by (1) transesophageal echocardiography in the operating room (incidence: 0/25, 0%, 70% CL 0% to 7.3%); (2) discharge auscultation (incidence: 1/30, 3%, 70% CL 0.5% to 10.8%); and (3) follow-up Doppler echocardiography (incidence: 3/25, 12%, 70% CL 5.4% to 22.6%). Video-assisted thoracoscopic techniques can be safely applied to pediatric patients with patent ductus arteriosus and vascular rings and may become an effective addition to the staged management of more complex forms of congenital heart disease.