Extracranial arteriovenous malformation (AVM) is a high-flow vascular malformation, of which the first-line therapies including surgery and ethanol embolization are of high risk. Besides, the outcomes of complex cases are usually poor. Therefore, it is urgent to accelerate the development of target therapy for extracranial AVM, based on the discoveries in pathogenesis and genetics. Breakthroughs have been made on the genetic research of extracranial AVM, as somatic mutations of RAS/RAF/MAPK signaling pathway genes have been found in this entity. Genetic polymorphism and epigenetics might also play important role in the development of the disease. Several anti-angiogenic treatment emerge therapeutic effects on extracranial AVM, meanwhile high-throughput proteomics ignites the sparks of precision medicine. This review focuses on the advancement in the pathogenesis, genetics and target therapy related to extracranial arteriovenous malformations.

Extracranial arteriovenous malformation (AVM) is a high-flow vascular malformation, of which the first-line therapies including surgery and ethanol embolization are of high risk. Besides, the outcomes of complex cases are usually poor. Therefore, it is urgent to accelerate the development of target therapy for extracranial AVM, based on the discoveries in pathogenesis and genetics. Breakthroughs have been made on the genetic research of extracranial AVM, as somatic mutations of RAS/RAF/MAPK signaling pathway genes have been found in this entity. Genetic polymorphism and epigenetics might also play important role in the development of the disease. Several anti-angiogenic treatment emerge therapeutic effects on extracranial AVM, meanwhile high-throughput proteomics ignites the sparks of precision medicine. This review focuses on the advancement in the pathogenesis, genetics and target therapy related to extracranial arteriovenous malformations.

Objective:This study proposed a new clinical classification and treatment strategies for periocular arteriovenous malformation (AVM).Methods:A retrospective analysis of the cases of periocular AVM from Jan 2015 to Jan 2019 was included in this study. According to the DSA angiography results, which type of the ophthalmic artery connected with the AVMs, three types of classification were initiated: type 1 is unilateral ophthalmic artery blood supply the lesion and the central retinal artery is not involved; type 2 is bilateral ophthalmic artery blood supply and the central retinal artery is not involved; type 3 is unilateral or bilateral ophthalmic artery blood supply and the central retinal artery is involved. Type 3 can be subdivided into 3a and 3b subtypes according to the visual acuity of the affected eye. Type 3a is the presence of vision; type 3b is the loss of vision. Type 1 patients were treated with super-selective onyx embolisation of the feeding arteries of AVMs through the ocular arteries and then treated with ethanol embolotherapy; Type 2 patients were treated with bilateral super-selection onyx embolisation of the feeding arteries of AVMs through the ocular arteries and then were treated with ethanol embolotherapy; type 3a patients were treated with ethanol embolotherapy combined with surgery; type 3b patients were treated with enucleation and orbital reconstruction.Results:There were 32 cases in this study. For 6 cases of type 1, The treatment course was 1-5 sessions, with an average of 2.1 sessions. 5 cases were cured, 1 case was improved, 1 case occured minor complication (superficial tissue necrosis), which was self-healing; In 8 cases of type 2, 4 cases were treated with interventional therapy for 1-7 sessions, with an average of 2.5 sessions. 3 cases were cured, 5 cases were improved, 1 case had minor complication (superficial tissue necrosis). Among the 4 cases treated by operation, 3 cases were repaired by expanded flap, 1 case by local flap. 1 case was cured, and 3 cases was improved, without operation related complications; In 13 cases of type 3a, 3 cases was cured, 10 cases was improved, 2 cases had intervention therapy related minor complications (superficial tissue necrosis) which was self-healed, 1 case had operation related complications (small area necrosis of flap, necrosis area was treated by dressing). In 5 cases of 3b type, 2 cases were cured, 3 cases were improved, and 1 case had operation related complication (partial necrosis of flap, thedefect was further repaired by skin grafting).Conclusions:The classification of periocular arteriovenous malformations has its significance for guiding the selection of treatment strategies. Combining ethanol embolotherapy, neurological intervention techniques, and plastic and reconstructive techniques are essential to achieve better clinical outcome in the treatment of periocular AVM with minimal complications.

Objective:To assess the treatment outcome of patients with head and facial arteriovenous malformation treated with absolute ethanol embolization alone, resection alone or combined ethanol embolization-resection.Methods:Medical records of 74 patients [41 male and 33 female; age mean, ( 29.1±10.6 )years]) with head and facial arteriovenous malformation between January of 2014 and December of 2018 were reviewed retrospectively. The most common sites were ear( n=25), cheek( n=20), and lip( n=18). Based on the pattern of lesion location and extent, a classified treatment strategy including ethanol alone, surgical resection and combined ethanol embolization-resection was established to gain satisfied treatment efficacy. Results:In total, cure was achieved in 50 patients (67.6%), and improvement was achieved in 24 patients. Ethanol embolization alone was performed in 42 patients [mean, ( 2.6±1.2) sessions]. The dosage of ethanol used per single session ranged from was 1.5 to 24.0 ml. Cure was achieved in 27 patients (64.3%), and improvement was achieved in 15 patients (35.7%). Surgical resection alone was performed in 15 patients. Cure was achieved in 12 patients (80.0%), and improvement was achieved in 2 patients (20%). Local flaps were performed in 2 patients, expanded flaps in 11 patients, and free flaps in 2 patients. Combined ethanol embolization-resection was performed in 17 patients. Cure was achieved in 11 patients (64.7%), and improvement was achieved in 6 patients (35.3%). In total, cure was achieved in 50 (67.6%) patients, improvement was achieved in 24 (32.4%) patients, with a follow-up of 27.0±11.3 months. A total of 2 major complications occurred in 2 patients. One patient experienced recurrence. Lesions involving ≥2 cervicofacial subunits had a lower cure rare compared with localized lesions ( P<0.05). Treatment outcomes were not significantly related to the treatment modalities ( P>0.05). Conclusions:Surgical resection and ethanol embolization, alone or combination, should be integrated in a regimen to treat head and facial arteriovenous malformation for gaining both satisfied treatment efficacy and optimal cosmetic outcome.

Objective:This study proposed a new clinical classification and treatment strategies for periocular arteriovenous malformation (AVM).Methods:A retrospective analysis of the cases of periocular AVM from Jan 2015 to Jan 2019 was included in this study. According to the DSA angiography results, which type of the ophthalmic artery connected with the AVMs, three types of classification were initiated: type 1 is unilateral ophthalmic artery blood supply the lesion and the central retinal artery is not involved; type 2 is bilateral ophthalmic artery blood supply and the central retinal artery is not involved; type 3 is unilateral or bilateral ophthalmic artery blood supply and the central retinal artery is involved. Type 3 can be subdivided into 3a and 3b subtypes according to the visual acuity of the affected eye. Type 3a is the presence of vision; type 3b is the loss of vision. Type 1 patients were treated with super-selective onyx embolisation of the feeding arteries of AVMs through the ocular arteries and then treated with ethanol embolotherapy; Type 2 patients were treated with bilateral super-selection onyx embolisation of the feeding arteries of AVMs through the ocular arteries and then were treated with ethanol embolotherapy; type 3a patients were treated with ethanol embolotherapy combined with surgery; type 3b patients were treated with enucleation and orbital reconstruction.Results:There were 32 cases in this study. For 6 cases of type 1, The treatment course was 1-5 sessions, with an average of 2.1 sessions. 5 cases were cured, 1 case was improved, 1 case occured minor complication (superficial tissue necrosis), which was self-healing; In 8 cases of type 2, 4 cases were treated with interventional therapy for 1-7 sessions, with an average of 2.5 sessions. 3 cases were cured, 5 cases were improved, 1 case had minor complication (superficial tissue necrosis). Among the 4 cases treated by operation, 3 cases were repaired by expanded flap, 1 case by local flap. 1 case was cured, and 3 cases was improved, without operation related complications; In 13 cases of type 3a, 3 cases was cured, 10 cases was improved, 2 cases had intervention therapy related minor complications (superficial tissue necrosis) which was self-healed, 1 case had operation related complications (small area necrosis of flap, necrosis area was treated by dressing). In 5 cases of 3b type, 2 cases were cured, 3 cases were improved, and 1 case had operation related complication (partial necrosis of flap, thedefect was further repaired by skin grafting).Conclusions:The classification of periocular arteriovenous malformations has its significance for guiding the selection of treatment strategies. Combining ethanol embolotherapy, neurological intervention techniques, and plastic and reconstructive techniques are essential to achieve better clinical outcome in the treatment of periocular AVM with minimal complications.

Objective:To assess the treatment outcome of patients with head and facial arteriovenous malformation treated with absolute ethanol embolization alone, resection alone or combined ethanol embolization-resection.Methods:Medical records of 74 patients [41 male and 33 female; age mean, ( 29.1±10.6 )years]) with head and facial arteriovenous malformation between January of 2014 and December of 2018 were reviewed retrospectively. The most common sites were ear( n=25), cheek( n=20), and lip( n=18). Based on the pattern of lesion location and extent, a classified treatment strategy including ethanol alone, surgical resection and combined ethanol embolization-resection was established to gain satisfied treatment efficacy. Results:In total, cure was achieved in 50 patients (67.6%), and improvement was achieved in 24 patients. Ethanol embolization alone was performed in 42 patients [mean, ( 2.6±1.2) sessions]. The dosage of ethanol used per single session ranged from was 1.5 to 24.0 ml. Cure was achieved in 27 patients (64.3%), and improvement was achieved in 15 patients (35.7%). Surgical resection alone was performed in 15 patients. Cure was achieved in 12 patients (80.0%), and improvement was achieved in 2 patients (20%). Local flaps were performed in 2 patients, expanded flaps in 11 patients, and free flaps in 2 patients. Combined ethanol embolization-resection was performed in 17 patients. Cure was achieved in 11 patients (64.7%), and improvement was achieved in 6 patients (35.3%). In total, cure was achieved in 50 (67.6%) patients, improvement was achieved in 24 (32.4%) patients, with a follow-up of 27.0±11.3 months. A total of 2 major complications occurred in 2 patients. One patient experienced recurrence. Lesions involving ≥2 cervicofacial subunits had a lower cure rare compared with localized lesions ( P<0.05). Treatment outcomes were not significantly related to the treatment modalities ( P>0.05). Conclusions:Surgical resection and ethanol embolization, alone or combination, should be integrated in a regimen to treat head and facial arteriovenous malformation for gaining both satisfied treatment efficacy and optimal cosmetic outcome.