Anomaly of Haughton type D left cervical aortic arch in combination with type B dissection: case report and literature review

In 1975, Haughton published the classification of the cervical aortic arches and distinguished between five different types (Haughton type A-E) respecting the configuration of the aorta, the sequence of brachiocephalic branching and embryogenesis [1]. Moreover, Haugthon documented 25 cases of cervical aortic arches, of which four showed a type D configuration. In the same year, Moncada et al. published their review focusing on 23 cases and the association with cardiac anomalies [2]. Compared to further configurations of cervical arches, it is noticeable that the type D arches primarily demonstrate a surgical challenge. It is characterized by an ipsilateral descending aorta, a normal sequence of brachiocephalic branching and a coarctation of the arch leading to a potential risk of development of an aneurysm. Cardiac anomalies do not tend to be associated with this type of aortic anomaly. A correlation with the occurrence of aortic dissection has never been reported since our recent publication of images of a 33-year old woman in 2014 [3]. Most aortic arch aneurysms of Haughton type D occur between the left common carotid and left axillary artery [4]. Analyzing the 44 patients, who are documented since 1968 in the current literature, the left cervical aortic arch is diagnosed mainly in younger women in their 20ties or 30ties. The symptoms range from a painless pulsating mass to dyspnea and dysphagia. Three cases are described as ruptured aneurysms requiring emergency treatment [5‐7]. We analysed 39 publications describing 44 cases of type D cervical arch [2, 4‐40] (Table 1). Based on this analysis, we describe the experience and therapy of our case. Because of the aneurysm formation in young patients, the type D cervical arch is an essential pathology to be discussed in a surgical forum. Facing its rarity and the lack of a standardized therapy, a summary of surgical interventions and outcome might be helpful for the treatment of this unusual disease.

A 43-year old, asymptomatic woman was admitted to our hospital by her family doctor after receiving a chest-x-ray during routine clinical examination. The x-ray showed a mediastinal mass overlapping the aortic arch region (Fig. 1). For verification a computed tomography (CT) was performed and revealed incidentally a type B dissection, which was most likely chronic without information of the index date, originating from an aneurysm of a left cervical arch with a maximum diameter of 6 cm (Fig. 2a-c). The left renal artery, the coeliac trunc and the main part of the superior mesenteric artery branched from the false lumen without a sign of malperfusion of the organs. Because of the huge diameter and the potential risk of rupture, an urgent surgical repair was planned. Before intervention the patient got a blood pressure adjustment by ACE inhibitor. Betablocker was not necessary because of a resting pulse under 60 beats per minute. For neurological online monitoring, sensitive and motor evoked potentials were monitored. Spinal drainage was installed 1 day before the procedure. Surgical access was carried out through median sternotomy and an additional left lateral thoracic incision through the fourth intercostal space (Hemi-Clemshell). Simultaneously to the preparation of the aneurysm, partial cardiopulmonary bypass was installed in the left groin by cannulation of the femoral artery and vein under echocardiographic guidance. During selective ventilation of the right side, the left lung was mobilized by transsection of the Ligamentum pulmonale and preparation of the perianeurysmatic tissue and adhesions. After identification and preparation of the recurrent and phrenic nerve and the supraaortal branches, the descending aorta was clamped and a distal anastomosis performed with a straight graft (20 mm). The visceral arteries partially branched from the false and true lumen without a sign of malperfusion. Before the final distal anastomosis, we performed a fenestration of the dissection membrane about a length of 5 cm to keep the perfusion of both lumina. The left carotid artery originated from the aortic arch with a distance of only 1 cm from the aneurysm. The left axillary artery branched directly from the aneurysm and was dissected and reimplanted with a separate 8 mm sidegraft to the 20 mm straight graft between the distal arch and proximal descending aorta. (Fig. 3a, b). The procedure was performed with partial cardiopulmonary bypass (CPB) of 87 min, aortic clamp time of 62 min under normothermic condition. The patient was extubated on first postoperative day and recovered well.

Biopsy of aortic tissue showed a picture consistent with arteriosclerosis and loss of smooth muscle cells, rupture of the elastic fibres and fibrosis of the media. The intima could not be visualized in detail.

The patient was discharged to cardiac rehabilitation at 13th postoperative day and recovered well. Last follow up with computed tomography was performed 3, 5 years after initial operation with a good and stable result of the dissection membrane and a perfusion of both lumina. The patient is able to resume a normal life without limitations.

The left cervical aortic arch type D is a rare disease, which is prone to aneurysm formation due to abnormal flow patterns and tortuosity and redundancy of aorta. It might play a role as potential, life threatening vascular disease. The difficulty lays in the identification of the pathology, especially in the physical examination, since a pulsating mass or cervical murmur seem to be the most specific symptoms in the majority of young, female patients. If diagnosed, surgical therapy with resection of the aneurysm and reimplantation of the axillary artery under cardiopulmonary bypass demonstrates the treatment of choice. Endovascular treatment might be an option in selected patients.