In addition blood pressure cuffs should also be placed on one leg and both arms to confirm the absence of a pressure gradient when the intended point of division of the lesser arch is temporarily occluded with forceps. Open division of vascular ring
Isolated double aortic arch without associated intracardiac defects is a vascular anomaly that can be corrected without the support of cardiopulmonary bypass.For surgical division of the narrower left aortic arch in a typical double arch patient with a dominant right arch, the patient is placed on the right side. After prepping and draping of the left chest a posterolateral thoracotomy is performed. The chest cavity is entered between the fourth and fifth rib (fourth intercostal space, as in the operation for patent ductus arteriosus or coarctation). After pulling the left lung aside, the layer (mediastinal pleura) above the left arch is incised and the left arch and the ligamentum arteriosum are dissected out and separated from the surrounding structures. The ligamentum is divided and two vascular clamps are placed on the junction of the left arch with the descending aorta. After division the two aortic ends are oversewn with 2 running layers of non-absorbable sutures. The end of the left arch is now further dissected from the mediastinal tissues for relief of any remaining constricting mechanism. The medial surface of the descending aorta and the distal end are also carefully dissected away from the esophagus.
Additional relief can be obtained by stitching the lateral wall of the aorta to the adjacent rib to pull it away from the esophagus.After insertion of a chest tube to prevent hemothorax and/or pneumothorax, the fourth and fifth rib are approximated by an absorbable suture. The surgery is completed by closure of the left thoracotomy wound in layers.In most centers, the mortality risk for surgery is between zero and 2%. A specific risk of open surgical repair of double aortic arch is injury to the recurrent laryngeal nerve, which can cause vocal cord paralysis. Injury to the lymphatic system can lead to postoperative chylothorax. Additional risks include lung injury, bleeding with the need for blood transfusions and wound infection. Postoperative care
After the surgery, some patients require intubation and mechanical ventilation for several days to allow adequate tracheal toilet, but most patients can have the tubes removed soon after the surgery. The obstructive airway symptoms may be worse in the first postoperative weeks. Only a few patients have immediate relief of stridor, but many obtain immediate relief of problems with swallowing (dysphagia). After extubation, it might be necessary to maintain positive airway pressure by appropriate flows of a humidified oxygen/air mixture. Epidemiology
Complete vascular rings represent about 0.5-1% of all congenital cardiovascular malformations. The majority of these are double aortic arches. There is no known gender preference, i.e. males and females are about equally affected. There is also no known ethnic or geographic disposition.Associated cardiovascular anomalies are found in 10-15% of patients.