“…The general consensus of 12 RCTs, two non-randomized controlled studies, two prospective single arm trials, one combined prospective and retrospective controlled study, and one prospective cohort study is that MMA embolization, when applied as a primary standalone treatment, in recurrent cSDH, or as a prophylaxis after surgery, is a safe and efficient method, with lower recurrence rates when compared to the conventional management of cSDH [ 86 ]. There is, however, significant heterogeneity in data element collection, making the formulation of type A recommendations premature [ 3 , 86 , 87 , 88 , 114 , 115 , 116 , 117 , 118 , 119 , 120 , 121 , 122 , 123 ]. In four of the most recent meta-analyses by Ironside et al (2021), Srivatsan et al (2019), Haldrup et al (2020) and Jumah et al (2020), the recurrence rates in patients with cSDH who underwent the embolization of MMA either as a primary treatment or in recurrent cSDH were 4.8%, 2.1–3.6%, 2.4–4.1% and 2.8%, respectively [ 114 , 120 , 121 , 122 ].…”