Rupture risk assessment for cerebral arteriovenous malformations

Background. Hemorrhage from cerebral arteriovenous malformation (cAVM) is a formidable manifestation of the disease, which is characterized by a high risk of death and disability. Individual assessment of the hemorrhage risk from cAVM would allow choosing the most adequate treatment tactics taking into account the expected rupture risk and the patient’s age at hemorrhagic manifestation. Aim. to develop a method for individual prediction of the cAVM risk rupture during the natural course of the disease. Material and methods. A retrospective analysis of demographic characteristics, clinical manifestations, and instrumental research data was performed in 104 patients with cAVM who underwent treatment from 2011 to 2023. Results. Hemorrhage occurred in 40 (38.5 %) of 104 patients, while in 35 (33.7 %) patients it was the first manifestation of cAVM. The median age of patients at time of cAVM rupture was 55 (95 % CI 49–61) years. A new method for predicting the risks of cAVM rupture was developed based on 4 factors that were identified as a result of regression analysis and rupture risk analysis (Cox and Weibull models), as well as clinical considerations. The developed DSSF scale takes into account the following parameters: deep outflow deficit ( p = 0.022), maximal node size ( p = 0.012), side of cAVM location ( p = 0.014), absence of fistula ( p = 0.072). Patients can be divided into 3 categories based on the sum of points obtained while assessing 4 characteristics of cAVM using the DSSF scale. The proposed cAVM assessment system was the following: +3 points – left side of the brain; – 1 point – maximum size of the cAVM node per each 1 cm; +4 points – deep outflow deficiency; +2 points – absence of fistula. The low-risk group (group A) included patients with the following set of parameters: – 2 points or less for cAVM; 43 % of the sample; median patients’ age at the time of cAVM rupture – 64 [60, 72] years. The moderate risk group (B) included the following parameters: from –1 to +1 points for cAVM; 39.4 % of the sample; median patients’ age at the time of cAVM rupture – 50 [44, 59] years. The high risk group (C) included the following parameters: +2 or more points for cAVM; 17.3 % of the sample; median patients’ age at the time of cAVM rupture – 38 [30, 48] years. The risk of hemorrhage from cAVM for patients in group A was 0 at 20; 8 at 30; 12 at 40; 17 at 50; 17 % at 60 years old. In the same age categories, these data for group B were 0, 8, 19, 41 and 80 %, for group C – 11, 29, 60, 79 % and about 100 %. Conclusion . The proposed method for assessing the hemorrhage risk for cAVM allows ranking patients into groups with low, moderate or high risk of intracranial bleeding, suggesting the patients’ age at time of cAVM rupture and choosing the adequate treatment tactics in terms of surgical aggression and time to cAVM elimination.