Hybrid endovascular repair of Kommerell diverticulum and aberrant right subclavian artery in a patient with repaired coarctation of the aorta.

Aberrant right subclavian (Lusoria) artery (ARSA) has a prevalence of 0.5-1.5% in the general population [1]. Kommerell diverticulum (KD) is by definition a dilatation at the base of the ARSA. Although it is usually asymptomatic, ARSA can cause symptoms such as dysphagia, coughing or even Horner syndrome. The traditional therapy has been open surgical repair with carotid-subclavian bypass (CSB) and resection of the ARSA aneurysm with replacement of the abnormal portion of descending aorta with a graft [2]. Recently, the use of hybrid endovascular therapy in complex congenital anatomy has been increasing. Hybrid repair of ARSA with KD was first described by Lacroix et al. [1] and has since been performed by others with satisfying outcomes [3], however, no reports of concurrent aortic coarctation complicating this repair has been documented. Total endovascular approaches have been reserved for specific cases where the anatomy and the tortuousness of the aortic arch allow such interventions without posing a risk [4]. We describe for the first time a case of successful hybrid endovascular repair of ARSA associated with a KD at the site of a previously repaired pre and post-ductal coarctation of the aorta. The patient is a 55-year old female with an ARSA coming off a KD. Her past medical history is notable for a coarctation of the aorta repaired at the age of 15 and a Ross procedure at the age of 41 for severe calcific aortic stenosis. It was noted on imaging that an ARSA arose 2 cm distal to the left subclavian artery (LSA) at the previously repaired coarctation of the aorta, with a 5 cm KD aneurysm (Figure 1).

Preoperative three-dimensional CT reconstructions showing Kommerell diverticulum with aberrant right subclavian artery coming off of it and relationship with other vessels. KD = Kommerell diverticulum; LSA = Left subclavian artery; ARSA = Aberrant right subclavian artery; LCA = Left common carotid artery; RCA = Right common carotid artery.

Since the proximal landing zone of the thoracic endograft has to be proximal to the LSA, we chose a two-stage approach consisting of right CSB followed by left CSB and endovascular ARSA aneurysm exclusion. First a right CSB (PTFE, Gore-Tex, 6 mm in diameter) was performed through a supraclavicular approach, with surgical ligation of the right subclavian artery (proximal to anastomosis to prevent a Type II endoleak). Twelve days later, a left CSB (PTFE, Gore-Tex, 6mm in diameter) was done, immediately followed by thoracic endografting in the same setting. A Cook TX2 endograft (28 mm x 120 mm) was advanced through the right common femoral artery over a Lunderquist wire into the aortic arch, distal to the head vessels and proximal to the aneurysm and LSA. This placement was confirmed with multiple aortograms. The device was deployed with a 3 cm landing zone proximally. Excellent apposition was noted proximally and distally; a small, clinically insignificant Type II endoleak was seen, due to the contribution of the LSA retrograde. The proximal and mid portions of the graft were ballooned with a 36 CODA balloon. Repeat angiography revealed almost no Type II leak and the complete exclusion of the aneurysm of KD (Figure 2).

Postoperative three-dimensional CT reconstructions showing good positioning of endograft with exclusion of the diverticulum and no sign of endoleak, patent bilateral carotid-subclavian bypass grafts. LCA = Left common carotid artery; RCA = Right common carotid artery.

The patient was extubated in the operating room and was taken to the intensive care unit without vasopressor support. She had no postoperative complications and was discharged home on postop day 3. The patient was still asymptomatic at 12 months postoperatively. Due to its low prevalence and the heterogeneity of the patients, there are still no well-established guidelines for the treatment of KD with an ARSA. Our report reinforces the ease and safety of the 2-stage hybrid approach, as well as highlights the advantage the technique carries over both the traditional open repair and the total endovascular approach. On one hand, being less invasive than open repairs, the hybrid endovascular technique spares the need for cardiopulmonary bypass and deep hypothermic arrest, and thus is suitable for high-risk patients. On the other hand, when compared to total endovascular repairs, a hybrid technique is more versatile and allows for a larger margin of maneuver. Although at first appealing, a total endovascular approach should be considered with caution since its success is highly dependent on the individual anatomy of the aneurysm.