Left-sided cervical aortic arch aneurysm: case report

Abstract

Cervical aortic arch is a rare type of vascular congenital anomaly. Aneurysmal formation has been reported in only 10 cases but is seen occasionally by experienced thoracic aortic surgeons.1Farsak B Yilmaz M Kaplan S Böke E Cervical aortic arch with aneurysm formation.Eur J Cardiothorac Surg. 1998; 14: 437-439Crossref PubMed Scopus (18) Google Scholar Although most of the patients with this anomaly are asymptomatic, newer imaging techniques demonstrate aneurysmal change in the cervical arch, and pathologic findings in surgical series support the indication for surgical intervention.2Cooly D.A Mullins C.E Gooch J.B Aneurysm of right-sided cervical arch; surgical removal and graft replacement.J Thorac Cardiovasc Surg. 1976; 72: 106-108PubMed Google Scholar A 16-year-old woman was admitted to Asahi General Hospital with a pulsatile mass in the left neck. Blood pressure was 110/60 mm Hg in the right arm and 90/60 mm Hg in the left arm. Examination of the neck revealed a visible 4-cm pulsatile mass in the left supraclavicular region. A thrill with a grade II/VI bruit was noted over the left carotid artery. Chest radiography revealed a smooth left-sided mediastinal mass. Three-dimensional computed tomography (3D-CT), magnetic resonance angiography (MRA), and aortography revealed a saccular aneurysm of the cervical aortic arch just distal to the origin of the left carotid artery, with normal branching. An aberrant and torturous left subclavian artery originated from the distal end of the aneurysm (Figure 1). The aortic arch, the descending aorta, and the left subclavian artery were accessed via a left thoracotomy in the fourth intercostal space. The left superior vena cava was dissected from the aneurysm. After systemic heparinization (200 IU/kg body weight), the descending aorta and inferior vena cava were cannulated, and partial cardiopulmonary bypass was established. After core cooling to a rectal temperature of 34°C, the aorta was then clamped just distal to the left carotid artery and the descending aorta, after which the subclavian artery was clamped and divided. The aneurysm was excised, and a 22-mm Hemashield graft (woven double velour graft; Boston Scientific, Natick, Mass) was anastomosed in an end-to-end fashion. The aberrant subclavian artery was reconstructed to the side of the graft by using an interposed 8-mm Hemashield graft. Pathologic examination revealed cystic medial degeneration of the aortic arch. Deletion of chromosome 22q11 was not detected in genetic analysis. The postoperative course and 4-year follow-up were uneventful (Figure 2). Cervical arch abnormalities are not that rare to experienced, high-volume thoracic aortic surgeons and are common in patients with a bicuspid aortic valve. However, this condition is rarely reported or discussed in the literature. Cervical aortic arch was first described in 1914, and it was postulated that the anomaly arises from an abnormal persistence of the third aortic arch and the regression of the fourth arch, which normally forms the aortic arch.3Reid D.G Three examples of a right aortic arch.J Anat Physiol. 1914; 48: 174-181PubMed Google Scholar The pathophysiology of aneurysmal dilatation is unknown. Most patients with this malformation are asymptomatic but patients may have symptoms of vascular compression of the esophagus and trachea, which manifest as dysphagia, dyspnea, or frequent pulmonary infections. Dysphagia and respiratory distress are associated with a right-sided cervical arch, whereas aneurysmal formations are more often associated with a left-sided cervical arch. Physical examination reveals a large pulsatile mass in the supraclavicular region.4Morris R Ruttley M Left cervical aortic arch associated with aortic aneurysm.Br Heart J. 1978; 40: 87-90Crossref PubMed Scopus (17) Google Scholar 3D-CT, angiography and MRA are useful for definite diagnosis and surgical treatment. Deletion of chromosome 22q11 was recently reported in some cases of cervical aortic arch5Kumar A McCombs J.L Sapire D.W Deletions in chromosome 22q11 region in cervical aortic arch.Am J Cardiol. 1997; 79: 388-390Abstract Full Text Full Text PDF PubMed Scopus (28) Google Scholar but was not evident in this case. The female predilection for aneurysm formation is consistent with a genetic factor.1Farsak B Yilmaz M Kaplan S Böke E Cervical aortic arch with aneurysm formation.Eur J Cardiothorac Surg. 1998; 14: 437-439Crossref PubMed Scopus (18) Google Scholar The pathologic finding of cystic medial degeneration in the aneurysm has been reported in a large surgical series and supports the importance of recognition and surgical intervention in this condition, whether patients are symptomatic or not.2Cooly D.A Mullins C.E Gooch J.B Aneurysm of right-sided cervical arch; surgical removal and graft replacement.J Thorac Cardiovasc Surg. 1976; 72: 106-108PubMed Google Scholar