Effect of cannabis consumption on characteristics and evolution of thromboangitis obliterans

Background: Thromboangiitis obliterans (TAO) is a distal non atherosclerotic thrombotic vasculitis affecting tobacco smokers. The role of cannabis co-exposure remains controversial. The study aims to assess how cannabis consumption influences clinical presentation and outcome of TAO in tobacco smokers. Patients and methods: TAO patients, according to Papa's criteria, were included in a retrospective bicentric study between the 1^st January 2003 and the 1^st march 2020. Clinical characteristics, arterial involvement at TAO diagnosis, vascular event and amputations during follow-up were analyzed according to cannabis consumption. Results: Seventy-three patients with TAO patients were included. Forty-five patients were in Tobacco group (T) and 28 in Tobacco and cannabis group (T&C). Tobacco exposure was less important in T&C group than in T group (19.4±11.3 vs 31.6±16.6 pack-years) (p=0.005) and patients in T&C group were younger at TAO diagnosis than in T group (p=0.008). Patients in T&C group presented more claudication (33.3% vs 8.9%, p=0.01) and less upper limbs resting ischemia (25.9% vs 51.1%, p=0.04) than patients in the T group. No differences were found between groups with regard to arterial distribution. Amputation rate for patients who had at least one major or minor amputation did not differ between T and T&C group (25% vs 14.8%, p=0.38). Conclusions: Cannabis consumption was associated with a younger age of TAO onset. However, it does not affect amputation-free survival, Tobacco exposure is less important in T&C patients; data of this bicentric study suggest that cannabis could be a cofactor of tobacco which accelerates TAO onset.