Stenosing processes occur in the subclavian artery (SA) less frequently than in the carotid artery or vertebral artery. However, the SA more frequently exhibits proximal and ostial stenoses near the origin from the aortic arch than the common carotid artery. Due to the vascular anatomy, the left SA is more commonly affected [1].
The presence of a stenosis of the SA is considered a predictor of cardiovascular and overall mortality [2]. Epidemiological data on the prevalence of SA stenosis in the USA is provided by the multi-ethnic epidemiological study on atherosclerosis (“MESA”). Accordingly, a stenosis could be detected in 4.5% of the subjects, with women being affected more frequently than men. Risk factors for the development of a stenosis included diabetes mellitus, arterial hypertension, high pulse amplitude, overweight, and elevated C-reactive protein [3]. In a cohort study, a prevalence of 1.9% was reported among subjects in a home setting and up to 7.1% among inpatients [4]. The prevalence of SA stenosis in the risk group with CHD is between 0.5-4%, and among patients with PAD it increases to more than 40% [5, 6].
In the guideline of the American Heart Association (“AHA”), various recommendations are given for the treatment of patients with occlusive diseases of the SA or the brachiocephalic trunk (BCT) [7]:
- Creation of an extra-anatomic carotid-subclavian bypass for patients with symptoms of the posterior cerebral circulation, provided there is no increased surgical risk
- endovascular procedures for patients with symptoms of the posterior cerebral circulation and high surgical risk
- Revascularization in case of symptoms of the anterior cerebral circulation or the upper extremities, if these are attributable to the occlusion of the BCT
- no revascularization for asymptomatic stenoses or occlusions (exception: internal thoracic artery is planned for coronary bypass)
The aforementioned recommendations can also be found in the 2017 published guideline of the European
Society for Vascular Surgery (“ESVS”) on the diagnosis and treatment of peripheral arterial occlusive diseases [8]. Revascularization of symptomatic SA stenoses or occlusions should therefore be considered. Regarding the choice of procedure, open surgical and endovascular techniques should be weighed individually, taking into account the lesion characteristics and risk factors.
For open surgical revascularization of SA stenoses or occlusions, various procedures with good results are available. The creation of a carotid-subclavian bypass (CSB) is considered technically simpler and faster to perform than subclavian transposition (ST). The long-term patency rates are 73-99% depending on the indication and chosen procedure [9, 10, 11].
The first successful balloon angioplasty for symptomatic subclavian stenosis was reported in 1980 [12]. Various balloon- and stent-supported techniques are now available for treatment, but the evidence base is not sufficient to validly demonstrate the superiority of one procedure [13]. In a systematic review, stent-supported angioplasty suggested a higher 1-year patency rate compared to balloon angioplasty [14]. However, a Cochrane review on this topic could not identify any methodologically high-quality studies [15]. The technical success rates are overall 94-96%, and the long-term patency rates > 83% after 5 years [16].