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

Abstract

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.

Keywords: anatomy; arteriovenous malformation; classification; diagnosis; prevalence.

Figure 1

Overall 5 year AVM and simple pAVM data. (A) AVM cases in every single year from March 27th, 2016 to March 31st, 2021 (P < 0.0001). (B) First-visit AVM patients in every single year from March 27th, 2016 to March 31st, 2021 (P = 0.0004). (C) Heat map of the distribution of simple pAVM patients in China.

Figure 2

Flow of participants in the study. CAVM, capillary-arteriovenous malformation.

Figure 3

Sex and age of simple pAVM patients. (A) Sex ratio of simple pAVM. (B) Age distribution of simple pAVM (P = 0.01).

Figure 4

Distribution of simple pAVM cohort according to classification. (A) Number of simple pAVM patients of each subtype. (B) Number of Type IA simple pAVM patients of each location. (C) Number of Type IB simple pAVM patients of each location. (D) Number of Type IIA simple pAVM patients of each location. (E) Number of Type IIB simple pAVM patients of each location (Concurrence: patients with simple pAVM in both maxilla and mandible).

Figure 5

Clinical manifestation of Type I simple pAVM. (A) Patient 1 with auricular AVM (type IA). (B) Patient 2 with AVM of hands (type IA). (C) Patient 3 with AVM of left foot (type IA). (D) Patient 4 with AVM of back (type IA). (E) Patient 5 with AVM of ear and parotideomasseteric region (type IB). (F) Patient 6 with AVM of right hand, forearm and elbow (type IB). (G) Patient 7 with AVM of trunk and gluteal region (type IB). (H) Patient 8 with AVM of back and abdomen (type IB). White arrow: cutaneous chromatosis. Dark arrow: cutaneous erythema. Red arrow: dilation of the outflow vein or external jugular vein. Blue arrow: scab or ulceration. Dark dotted box: the “steal phenomenon.”

Figure 6

Clinical manifestation of Type II simple pAVM. (A,B) Patient 11 with mandibular AVM, cortex was intact (type IIA). (C,D) Patient 12 with mandibular AVM, cortex was broken (type IIB). (E,F) Patient 13 with maxillary AVM, cortex was intact (type IIA). (G) Patient 14 with AVM of left hand and forearm, cortex was broken (type IIB). (H) Patient 15 with AVM of right thigh, cortex was broken (type IIB). Black arrow: cutaneous erythema. White arrow: purple stain of the gingiva or oral mucosa.

Figure 7

Imaging pictures of Type III simple pAVM patients. (A) Patient 18 with renal AVM. (B) Patient 19 with renal AVM. (C) Patient 20 with ascending colonic AVM. (D) Patient 21 with uterine AVM. (E) Patient 22 with uterine AVM. (F) Patient 23 with adnexal AVM. Red arrow: AVM lesion.

Figure 8

Clinical manifestation of Type IV simple pAVM. (A) Patient 24 with local soft tissue hyperplasia and exophthalmos of right eye. (B) Patient 25 with local swelling and exophthalmos of left eye. (C) Patient 26 with local swelling and pulsatile erythema. (D) Patient 27 with exophthalmos of left eye and conjunctival hyperplasia. (E) Patient 28 with local erythema and elevated cutaneous temperature. (F) Patient 29 with extensive swelling and dilated superficial veins, exophthalmos of left eye. (G) Patient 30 with sporadic erythema and elevated cutaneous temperature. (H) Patient 31 with sporadic swelling and dilated external jugular vein. White arrow: erythema. Black arrow: external jugular vein.