Left aortic arch with right descending aorta and right ligamentum arteriosum associated with d-TGA and large VSD: Surgical treatment of a rare form of vascular ring

Left Aortic Arch With Right Descending Aorta and Right Ligamenturn Arteriosum Associated With d-TGA and Large VSD: Surgical Treatment of a Rare Form of Vascular Ring By Mikio Watanabe,

Shiori

Kawasaki, Hiroshi Sato, Kazu Minami, Shinjiro Toshihiro Ino, and Yasuyuki Hosoda Tokyo, Japan

Shimazaki,

Katumi

Akimoto,

l A l-month-old boy with respiratory distress underwent pulmonary artery banding after diagnosis of d-loop transposition of the great arteries and ventricular septal defect. Respiratory distress recurred after surgery. Angiography, esophagography, and magnetic resonance imaging showed left aortic arch, retroesophageal aorta, and right descending aorta. Surgery at 9 months of age showed a right-sided ligamentum arteriosum. Division of the ligamentum relieved the constriction of the esophagus and trachea caused by this rare form of vascular ring. Copyright o 7995 by W.B. Saunders Company

INDEX WORDS: Vascular ing aorta, transposition imaging.

ring, left aortic of great arteries,

arch, right descendmagnetic resonance

I

N INFANTS with d-loop transposition of the great arteries (d-TGA) and a large ventricular septal defect (VSD), pulmonary hypertension develops quickly. Herein we describe a patient with severe respiratory distress who underwent pulmonary artery (PA) banding surgery, but later had respiratory failure that required intubation and mechanical respiratory support. Diagnostic imaging showed a left aortic arch, a right descending aorta, and effective PA banding. The clinical signs were strongly suggestive of upper airway obstruction and bronchomalacia, and were similar to those in the first surgically treated case of vascular ring, reported by Gross.’ Right-sided thoracotomy and division of the ligamentum arteriosum was performed. Respiratory distress gradually resolved, and the patient was extubated. CASE

REPORT

This infant boy weighed 3,430 g at birth; he was the product of a full-term pregnancy and normal delivery. A heart murmur, retractions, and peripheral cyanosis were detected at 1 month of age. Echocardiography showed d-TGA, a large VSD, and a huge PA. A chest x-ray showed cardiomegaly (cardiothoracic ratio of 62%) and increased pulmonary markings. He was transferred to Juntendo University Hospital. At 41 days of age, PA banding surgery, with a midline sternotomy approach, was performed to prevent pulmonary hypertension and treat respiratory distress. The ascending aorta (9 mm in diameter) was anterior to the cardiac outlet, and the PA (19 mm in diameter) was posterior to the ascending aorta. The PA was banded with a 4-mm-wide loop of Teflon tape that was 9 mm in diameter. After banding, the arterial pressure increased from 87143 mm Hg to 96150 mm Hg, and the PA pressure decrease from 57114 mm Hg to 39112 mm Hg. Oxygen saturation decreased from 86% to 76%. Recovery was uneventful, and the patient was

JournalofPedmfric

Surgery,

::r

Vol 30, No 9 (September),

1995: pp 1363-1365

Fig 1. Bronchography and esophagography. (A) Anterior view of the trachea with Dionosil injection. The trachea shifted slightly to the right. (B) Lateral view of the esophagus with Gastrografin injection. Note the posterior indentation and the anterior tapering.

From the Deparfments of Thoracic Surgery and Pediattics, Juntendo Umverszty School of Medicine, Tokyo, Japan. Address reprint requests to Dr Watanabe, Department of Thoracic Surgery, Juntendo Universig School of Medicine, 2-l-l Hongo, Bunkyo-ky Tokyo 113, Japan. Copyright Q 1995 by WB. Saunders Company 0022.3468/95/3009-0031$03.00l0

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wheezing continued, and recurrent respiratory infections developed. Cardiac catheterization performed at 5 months of age showed effective PA banding, d-TGA with a large VSD, and a left aortic arch with a right-sided descending aorta. The pressure in the ascending aorta was 65/40 mm Hg, that in the right and left ventricles was 6517 mm Hg, and that in the PA was 26/10 mm Hg. These findings suggested a vascular ring, but this diagnosis was not pursued because the combination is extremely rare. A contrast esophagogram, using Gastrografin, performed at 8 months of age showed compression of the posterosuperior esophagus (Fig 1). Contrast bronchography using Dionosil showed only tapering of the trachea. A chest x-ray showed hazy infiltration in the lower right and upper left lung fields (Fig 2A). ECG-gated spin-echo magnetic resonance imaging (MRI) showed the left aortic arch passing halfway around the trachea and the esophagus, as well as a huge PA. The possibility of a vascular ring comprising the left aortic arch, right descending aorta, and ligamentum arteriosum was considered. However, right ligamentum arteriosum was not confirmed. At 9 months of age, a right posterolateral thoracotomy was performed, dividing the azygos vein, and the superior mediastinum was dissected to identify the ligamentum arteriosum. A short (8

Fig 2. Chest x-ray before and after the second surgical procedure. (A) Before surgery to release the vascular ring, there was hazy infiltration in both lung fields (7/26/93). (B) One month after surgery, there was remarkable improvement in lung field findings. Cardiomegaly is still obvious (g/4/93).

extubated the following day. Respiratory distress improved after surgery, but 40 days later an upper respiratory tract infection developed and respiratory failure recurred. He was intubated and placed on a respirator; extubation was not possible until after the second surgical procedure. Inspiratory and expiratory stridor and

Fig 3. Arrangement of the great vessels, based on surgical findings and cardiovascular imaging. Transposition of the great arteries is shown. The anterior ascending aorta was 9 mm in diameter, and the posterior PA was 19 mm in diameter. The ascending aorta arose from the right common carotid artery and conjoined left subclavian and common carotid artery. The aortic arch traversed the retroesophageal space to the right side of the vertebral column and then became the descending aorta. It derived the right subclavian artery. A right ligamentum arteriosum bridged the descending aorta and right PA, and completed the vascular ring. AsA, ascending aorta; LeA, left arch; DeA, descending aorta; RCC, right common carotid artery; LSC, left subclavian artery; LCC, left common carotid artery; RSC, right subclavian artery; TR, trachea; ES, esophagus; Lig, ligamentum arteriosum; PA, pulmonary artery.

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mm) and thick (3 mm) ligamentum was found between the descending aorta and the right PA. The right subclavian artery arose from the descending aorta. The right vagus nerve and recurrent laryngeal nerve were observed, but no aortic diverticulum was found. The ligamentum was doubly ligated and divided, reducing tension between the PA and descending aorta and relieving constriction of the esophagus and trachea. The patient’s respiratory distress improved gradually, and he was extubated 35 days later. Stridor and wheezing resolved, and a chest x-ray showed remarkable improvement (Fig 2B). Milk intake increased, and he is currently awaiting definitive intracardiac repair of the TGA. DISCUSSION

Vascular ring, an anomaly of aortic arch development, is not common. Respiratory distress and dysphagia are the usual signs of vascular ring, and association with a left aortic arch and right descending aorta is very rare.2 This type of vascular ring was not found in reviews of surgical cases conducted by Richardson et al (n = 42),3 Hartyanszky et al (n = 111),4 and Inoue (n = 56).5 Only 19 cases of this combination have been reported,6-10 and surgical correction of this type has been reported for only seven cases.6-lo This type of vascular ring complicates various cardiac anomalies, such as absent left PA,6-9 VSD,6,8 and tetralogy of Fallot,6 but association with TGA had not been described. In this case, d-TGA, large VSD, and pulmonary hypertension were diagnosed by echocardiography, leading us to perform PA banding initially. However,

the patient’s respiratory problems continued. Aortography, esophagography, bronchography, and MRI showed compression of the esophagus and trachea by a retroesophageal aorta. A right ligamentum arteriosum was strongly suggested according to the rule stated by Edwards.2 However, this was not confirmed before the second surgical procedure, during which found a ligamentum arteriosum after right-sided thoracotomy; it was divided to release the vascular ring. This case shows that respiratory distress in an infant with intracardiac anomalies may also be caused by extracardiac anomalies of derivatives of the aortic arch. Except for the embryological development of TGA, this case would correspond to Edwards group II, type C (left-sided aortic arch with retroesophageal segment and superior segment of the descending aorta on the right side) (Fig 3).2 This is the first report of this type of vascular ring complicating TGA. Contrast esophagography is essential for diagnosis. Aortography also is required, and MRI can help clarify the anatomy. Echocardiography did not provide definitive diagnostic information in this case. An arterial switch procedure was not performed in this case because of the extremely small size of the left ventricle, owing to the large size of the VSD.

REFERENCES 1. Gross RE: Surgical relief for tracheal obstruction from a vascular ring. N Engl J Med 233:586-590, 1945 2. Edwards JE: Anomalies of the derivatives of the aortic system. Med Clin North Am 32:925-949.1948 3. Richardson JV, Doty DB, Rossi NP, et al: Operation for aortic arch anomalies. Ann Thorac Surg 31:426-432, 1981 4. Hartyanszky IL, Lozsadi K, Marcsek P, et al: Congenital vascular rings: Surgical management of 111 cases. Eur J Cardiothorat Surg 3:2.50-254, 1989 5. Inoue T: Kekkanrin (Vascular ring and related anomalies). Kyoubugeka 28:543-549,1975 (in Japanese) 6. Park SC, Siewers RD, Neches WH, et al: Left aortic arch with right descending aorta and right ligamentum arteriosum-A rare form of vascular ring. J Thorac Cardiovasc Surg 71:779-784,1976

7. Berman W, Yabek SM, Dillon T, et al: Vascular ring due to left aortic arch and right descending aorta. Circulation 63:458-460, 1981 8. Whitman G, Stephenson LW, Weinberg P: Vascular ring: Left cervical aortic arch, right descending aorta, and right ligamenturn arteriosum. J Thorac Cardiovasc Surg 83:311-315, 1982 9. Minami K, Sagoo KS, Matthies W, et al: Left aortic arch, retro-esophageal aortic segment, right descending aorta and right patent ductus arteriosus-A very rare vascular ring malformation. Thorac Cardiovasc Surg 34:395-397,1986 10. McFaul R, Millard P, Now&i E: Vascular rings necessitating right thoracotomy. J Thorac Cardiovasc Surg 82:306-309, 1981