Contemporary Management of Subclavian and Axillary Artery Aneurysms in Connective Tissue Disease: Navigating Therapeutic Uncertainty in a Rare Vascular Disease Without Dedicated Guidelines.

Abstract

Background: Subclavian artery aneurysms (SAAs) represent one of the rarest forms of peripheral arterial aneurysmal disease. Despite their low incidence, management in patients with underlying connective tissue disorders poses specific challenges related to intrinsic vessel fragility. Because of their rarity, the available literature is largely confined to case reports and small, heterogeneous retrospective series, and management remains largely experience-based rather than evidence-based. Explicit guidance from the Society for Vascular Surgery and the European Society for Vascular Surgery is lacking.

Methods: We performed a systematic review of the English-language literature to identify all reported cases of subclavian and axillary artery aneurysms in patients with heritable connective-tissue disorders. Searches were conducted in PubMed, Scopus, and Web of Science from inception to June 30, 2025. Data were extracted on treatment modality (open surgical, endovascular, or hybrid) and clinical outcomes (limb loss, revascularization patency, complications, and need for reintervention). The review protocol was registered on PROSPERO (CRD420261332695) RESULTS: Of 142 records identified, 24 studies met the inclusion criteria after duplicate removal and screening. These studies described 43 subclavian and axillary artery aneurysms in 25 patients (15 men [60%] and 10 women [40%]; median age, 46 years; range, 11-68). Aneurysm diameter was reported for 36 of 43 aneurysms (84%; median, 40 mm; range, 22-100 mm) and was not reported for the remaining 7 (16%). Marfan syndrome was the most frequent underlying disorder (20/25, 80%), followed by vascular Ehlers-Danlos syndrome type IV (3/25, 12%) and Loeys-Dietz syndrome/TGFBR2-related arteriopathy (2/25, 8%). Eight aneurysms (8/43, 19%) required urgent or emergent treatment. Treatment modalities comprised open surgical repair in 22 of 43 aneurysms (51%) - including interposition grafting in 12/22 (55%), bypass in 5/22 (23%), arterial ligation in 3/22 (14%), and aneurysmectomy with end-to-end anastomosis in 2/22 (9%) - hybrid procedures in 15 (35%), and endovascular therapy in 6 (14%) - including covered stent-grafting in 5/6 (83%) and coil/liquid embolization in 1/6 (17%). Immediate technical success - complete aneurysm exclusion without endoleak at the index procedure- was 95% (41 of 43 aneurysms). Two aneurysms (4.7%), both in the hybrid group, represented an index-procedure failure due to endoleak (one type I, one type III); freedom from reintervention was therefore 95% (41/43). Both were subsequently excluded after a secondary reintervention, yielding a delayed technical success rate of 100% (43/43). No 30-day mortality or limb loss was reported. Primary patency of the treated segment was 100% (43/43), as no graft/segment thrombosis, occlusion, or flow-limiting stenosis occurred; secondary patency was 100% (43/43). Where a numeric follow-up duration could be extracted, mean follow-up was 8 months (range, 6-11 months) in the endovascular group (4/5 patients), 15 months (range, 2 weeks-4 years) in the open group (5/13 patients), and 15 months (range, 1-60 months) in the hybrid group (6/7 patients); a precise duration was not reported for the remaining patients.

Conclusion: The available evidence demonstrates that both open and endovascular repair can achieve satisfactory short- and mid-term outcomes. However, patient selection, procedural planning, and surveillance protocols remain poorly standardized. The observed recurrences and the limited duration of follow-up reported in the literature underscore the need for rigorous, lifelong surveillance. Prospective multicenter registries are warranted to refine best practice and to guide the development of devices and techniques tailored to fragile connective-tissue vessels.