Novel classification for simple peripheral arteriovenous malformations based on anatomic localization: Prevalence data from the tertiary referral center in China

Background: In absence of the large-sample study of simple peripheral arteriovenous malfomations (pAVM), we aimed to perform the epidemiological analysis of over 1,000 simple pAVM patients from our center in the past 5 years, and establish a novel classification based on the anatomical localization of the primary lesion.

Results: Between March 27, 2016, and March 31, 2021, Chinese patients who were diagnosed with simple pAVM were taken into account. Those who suffered from simple arteriovenous malformations of the central nervous system (cnsAVM), combined types of AVM, and syndromes, such as CLOVES syndrome, etc. were all excluded from this study. A total of 1,070 simple pAVM patients were screened out. All of the simple pAVM patients were diagnosed by clinical manifestations and imaging examinations. Demographic data were obtained from the National Bureau of Statistics of China. The 5-year prevalence of simple pAVM was about (2.15-6.60) /1,000,000 population. The male-female ratio was approximately 1.22:1. The pAVM inpatients that were included in the age group of 21~30 years old had the highest constituent ratio (P = 0.01). The classification included four groups: Type I (primarily occurring in soft tissue); Type II (primarily occurring in bone); Type III (primarily occurring in the viscus) and Type IV (simple pAVM coexisting with CNS lesions). There were two subtypes of Type I: the A subtype (involving one major anatomical region) and the B subtype (involving two or more major anatomical regions); two subtypes of Type II: the A subtype (the cortex was intact) and the B subtype (the lesion had broken through the cortex). Generally, 657 patients were classified as Type IA (61.4%), 232 patients were Type IB (21.7%), 82 patients were Type IIA (7.7%) and 79 were categorized as Type IIB (7.4%); the number of patients who had Type III and Type IV pAVM were 9 (0.8%) and 11 (1.0%), respectively. The clinical manifestations and diagnostic standards for each type were also systematically summarized.

Conclusions: Prevalence data for simple pAVM were analyzed, and a novel classification was proposed based on the anatomy of the lesions. The present work was expected to facilitate the diagnosis of simple pAVM in clinical works.