Efficacy and safety of endovascular embolization for capillary malformation-arteriovenous malformation of the auricular and periauricular region in pediatric patients

Introduction

Capillary malformation-arteriovenous malformation (CM-AVM) syndrome is a rare autosomal dominant disorder (1,2). The prevalence is estimated to be about 1 in 100,000 among white individuals, according to the literature (2). The usual clinical presentations are cutaneous capillary malformations (CMs) and arteriovenous malformations (AVMs). CM-AVM can lead to cosmetic problems when located on the head, and CM-AVM may be associated with increased morbidity and mortality due to impaired physical function, life-threatening bleeding and chronic heart failure (3-5). CM-AVM of auricular and periauricular areas is rarely mentioned, but it may cause cosmetic problems and psychological disturbances.

To date, there are no guidelines for the treatment of CM-AVM. Endovascular embolization is the first-line treatment for high-flow vascular malformation (6,7). It can reduce the high-flow blood supply of vascular malformations with the advantages of minimal trauma, mild pain, and rapid recovery (7). Embolic agents, including iodized oil, polyvinyl alcohol and gelatin sponge (Gelfoam) have been used for embolization of vascular malformation. This study aims to present and discuss the management and outcomes of CM-AVM in auricular and periauricular area through endovascular embolization. We present this article in accordance with the STROBE reporting checklist (available at https://qims.amegroups.com/article/view/10.21037/qims-2025-1107/rc).

Methods

Study subjects

This retrospective study was approved by the Ethics Committee of the Children’s Hospital Affiliated to Shandong University (No. SDFE-IRB/T-2024096). Written informed consent was waived due to the retrospective nature of this study. This study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. This study enrolled 9 pediatric patients with CM-AVM of auricular and peri-auricular areas who were admitted to the Children’s Hospital affiliated to Shandong University from August 2020 to July 2024. The age of patients ranged from 1 year to 16 years. One patient was found on the auricle, three patients were in the periauricular areas, and five patients were in both auricular and periauricular areas. All patients presented for aesthetic concerns and/or parental anxiety. All patients had a family history of CMs. The diagnosis was initially determined by clinical manifestations and further confirmed by imaging examinations (including ultrasound, computed tomography and/or magnetic resonance imaging) and digital subtraction angiography (DSA). Final diagnosis was made by two senior clinicians with ten years of experience in the field of vascular malformations. Inclusion criteria for the study included: (I) children with complete data and follow-up records; (II) both clinical symptoms, imaging examinations, and DSA supporting diagnosis of CM-AVM; (III) children receiving no previous endovascular embolization therapy; (IV) Children receiving endovascular embolization in our hospital. Exclusion criteria were as follows: (I) cases with incomplete data; (II) children who did not receive endovascular embolization at our hospital. Genetic testing was not conducted due to refusal by the guardians of the patients.

Treatment protocols

All procedures were performed under general anesthesia using DSA equipment (Allura; Philips, Amsterdam, The Netherlands). In our usual endovascular embolization protocol, a 4-F sheath was placed into the right common femoral artery (Terumo Corporation, Tokyo, Japan); a 4-F Super Cobra catheter (Cook Medical, Bloomington, IN, USA) was used to perform selective arteriography of the ipsilateral common carotid artery to reveal the feeding vessel for CM-AVM. Super selective catheterization of the main feeding artery was implemented using a 1.98-F microcatheter (ASAHI INTECC, Seto, Japan). And we attempted to perform distal embolization as much as possible. Pingyangmycin was the drug used, and the embolic materials included Lipiodol (Guerbet, Aulnay-sous-Bois, France), polyvinyl alcohol (300–500 µm, Merit Medical, South Jordan, UT, USA), and gelatin sponge (350–560 µm, Alicon Pharm SCI & TEC, Hangzhou, China). Detailed usage instructions are as follows: (I) pingyangmycin (1 mg/mL): Lipiodol: water in a ratio of 2:1:1 using two 2.5 mL syringes and a three-way stopcock to prepare the pingyangmycin-Lipiodol emulsion; (II) For polyvinyl alcohol and gelatin sponge, pingyangmycin was first injected, followed by the embolic materials through the feeding artery through the feeding artery using a 2-mL syringe. A second arteriography showed contrast stasis and no significant flow into the lesions. If not, additional embolization was performed until the blood flow in the target vessel slowed significantly. The pingyangmycin in this article refers to pingyangmycin powder (Jilin Aodong Pharmaceutical Group Co., Ltd., Dunhua, China) mixed with dexamethasone dissolved in contrast agent (Iodixanol Injection, Beilu Pharmaceutical Co., Ltd., Beijing, China). The maximum dose of pingyangmycin was 10 mg/m² for a single session. The upper limit of cumulative dose was 160 mg/m². Radiation protection for the gonads and thyroid was performed during the procedure.

Follow-up and evaluation of treatment response

All patients in this study were followed up for at least one month after the first treatment. Postoperative efficacy evaluation is primarily based on clinical symptoms in combination with imaging examinations. The efficacy evaluation criteria were as follows: (I) Effective: the cutaneous temperature of the lesion area decreased and/or the CMs became less pronounced after one or multiple sessions. (II) Ineffective: there was no reduction in cutaneous temperature, and the CMs remained unchanged or worsened after multiple sessions.

Results

The median age of all patients was 7 years (interquartile range, 3–9 years). For all patients, the correct diagnosis was initially made based on clinical symptoms, careful history taking, and physical examination, and subsequently confirmed by ultrasound, computed tomography, and/or magnetic resonance imaging. The diagnosis was verified by DSA results. Regarding the locations of CM-AVM (Table 1), one patient had a lesion on the auricle, three had lesions in the periauricular area, and five had lesions in both the auricular and periauricular areas. All angiography and endovascular embolization were successfully performed. All patients received 1 to 4 treatments (Table 1), with an average number of 2.4±0.8 treatments. A total of 22 embolization treatments were performed, including 10 with polyvinyl alcohol, 10 with gelatin sponge, and 2 with iodized oil. Arterial angiography showed mild to moderate staining in the lesion area, which may be associated with enlarged feeding arteries, disordered blood vessels, and high velocity of blood flow. The main feeding artery in five patients was a branch of the posterior auricular artery. One patient had a branch of the occipital artery, and one had a branch of the facial artery. Two patients had multiple feeding arteries: one had branches of the posterior auricular and occipital arteries, while the other had branches of the posterior auricular, occipital, and superficial temporal arteries. In cases with multiple feeding arteries, we attempted to embolize all feeders in a single session whenever possible. Six patients were confirmed to have arteriovenous malformations (Table 1) beneath the CM areas, as shown by DSA. All patients experienced swelling after treatment, with only one case of transient allergic reaction observed. No pain, cutaneous necrosis, cerebral infarction or other complications were observed.

At a median follow-up of 8.0 months (interquartile range, 5.0–15.0 months; range, 4 to 47 months), all 9 patients were effectively treated (Figure 1), while only one patient had an obvious rebound of symptoms one week after the procedure. This was likely because the degree of embolization in the first treatment was relatively mild, and the treatment effect was effective after the second embolization treatment. Seven patients, along with their guardians, were satisfied with the cosmetic outcomes. One patient and the guardians thought that changes were not enough. Only one patient and the guardians thought that the cosmetic result was unsatisfactory.

Figure 1 Digital subtraction angiography comparison before and after endovascular embolization. Arteriography before (A) and after (B) endovascular embolization. Superselective feeding artery angiography before (C) and after (D) endovascular embolization.

Discussion

CM-AVM is an autosomal dominant disorder, first described by Eerola et al. (1) in 2003. The true prevalence is still unknown, with an estimated prevalence of about 1 in 100,000 (5). According to previous studies, capillary malformations typically presented as multifocal, pink to red, small cutaneous stains located on the face, trunk, and extremities, while solitary CMs, CMs with a diameter larger than 10 cm, and CMs with red to brown color were also described (1,2,8-10). AVMs could occur in brain, spine, skin, bone, and muscle, which were considered the key problem in CM-AVM syndrome and may lead to serious consequences (1,2,9,11,12). Histologically, CMs could be observed as an increase in the number of capillaries located in the upper dermis, while AVMs were mainly characterized by increased number of arterioles involving the entire thickness of the dermis (13). Previous studies mainly focused on lesions in the brain and spine (5), lesions in the auricular and periauricular area had rarely been reported, while they may lead to aesthetic problems and anxiety of patients and their guardians.

Careful history taking and physical examination may be helpful in the diagnosis of CM-AVM. To date, there is no consensus on diagnostic criteria for CM-AVM, but recommendations have been made (5). Therefore, we referred to the proposed diagnostic criteria and combined them with the experience of our department, imaging findings [including ultrasound (14), computed tomography and/or magnetic resonance imaging] and arteriographic findings by DSA to diagnose the patients.

To date, there are no published guidelines for the treatment of CM-AVM. A previous study by Iznardo et al. (15) showed that the CMs of 4 patients with CM-AVM (aged 5 to 19 years) had excellent treatment response to 595-nm pulsed dye laser after 3–6 sessions, with moderate response of one patient. Kim et al. (14) reported that a pediatric patient with CM-AVM received eleven sessions of 595-nm pulsed dye laser and the CMs lesions showed a good response. But pulsed dye laser mainly targeted superficial lesions, with limited effectiveness on deeper lesions and blood vessels. In our clinical practice, some patients exhibited a limited response to 595-nm pulsed dye laser. It usually requires multiple consecutive treatments, which can be expensive and may not be covered by insurance plan, and patients may experience varying degrees of purpura after treatment.

Interventional embolization has been the commonly used treatment of high-flow vascular malformation and the first-line choice for some lesions (6,7,16-18). It can reduce the high-flow blood supply of vascular malformations. Although CM-AVM may demonstrate increased or fast flow by Doppler (5,14,19), there were no reports on the use of interventional embolization therapy. Considering that CM-AVM may lead to impaired physical function, life-threatening bleeding, which is associated with increased morbidity and mortality, and considering the concerns of the patients’ guardians about their appearance and request for treatments, we attempted to perform interventional embolization for pediatric patients with CM-AVMs in the auricular and periauricular area. During the operation of transcatheter arterial embolization (Figure 2), we tried to perform distal embolization as much as possible for that proximal embolization of the feeding artery might be associated with recurrence (20). Due to the lack of experience in CM-AVM embolization treatment, we evaluated the effectiveness of different embolization materials (including pingyangmycin-Lipiodol emulsion, polyvinyl alcohol particles and Gelfoam particles). If the superselective feeding artery angiography showed that the staining of lesion was diffuse, pingyangmycin-Lipiodol emulsion was chosen, because Lipiodol, as a drug carrier, could prolong the retention time of pingyangmycin in the lesion to achieve better therapeutic effect. If only focal staining of lesion was observed on superselective feeding artery angiography, polyvinyl alcohol particles were chosen because they permanently occluded the feeding artery. If normal tissue staining was suspected on superselective feeding artery angiography, gelatin sponge particles were chosen because it is absorbable. The particle sizes of polyvinyl alcohol particles and gelatin sponge particles were selected because too small can easily cause pulmonary embolism, while too large cannot penetrate tiny abnormal blood vessels. All patients experienced a decrease in skin temperature or a lighter redness after treatment. One patient was observed with obvious symptoms rebounding one week after the operation. We suspected that the symptom rebound was due to the small amount of drug used given age and safety restrictions. No significant adverse reactions were observed across the 22 treatments, except for one patient who developed mild skin allergy after one treatment. A high proportion of patients (six patients) were found to have subcutaneous AVMs by DSA, which may be because the high blood flow of arteriovenous malformations leads to more obvious symptoms and thus patients seek medical treatment.

Figure 2 Two patients with capillary malformation-arteriovenous malformation. Clinical photographs of a 1-year-old boy before (A) and after (B) treatment, and a 10-year-old girl before (C) and after (D) treatment.

Recommendations for the management of patients with definite or suspected CM-AVM have been proposed, which include imaging tests for screening intracranial AVMs (5,21). But a study by Boccara et al. (12) suggested that the detection rate of central nervous system AVM seemed low in asymptomatic patients. In this study, no brain AVMs were found by imaging examination. However, AVMs were found subcutaneously in the lesion area, which may suggest that CM-AVM in the auricular and periauricular areas may be less likely to develop AVMs in the central nervous system.

There are several limitations in this study. Firstly, this study was a single-center retrospective study with a small sample size. Furthermore, the genetic testing was not performed due to the refusal by the guardians of the patients. We screened patients based on the recommended diagnostic criteria and symptoms, and ultimately confirmed the correct diagnosis through imaging examinations and DSA examinations. Thirdly, the follow-up period was relatively short, and a longer duration may be necessary to fully assess the lesions’ response.

Conclusions

In conclusion, DSA results showed that most patients had subcutaneous AVM. Given that the treatment was well tolerated and had no significant side effects, we believe that interventional embolization may become an alternative treatment of auricular and periauricular CM-AVM.

Acknowledgments

None.

Footnote

Reporting Checklist: The authors have completed the STROBE reporting checklist. Available at https://qims.amegroups.com/article/view/10.21037/qims-2025-1107/rc

Data Sharing Statement: Available at https://qims.amegroups.com/article/view/10.21037/qims-2025-1107/dss

Funding: None.

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://qims.amegroups.com/article/view/10.21037/qims-2025-1107/coif). The authors have no conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. This retrospective study was approved by the Ethics Committee of the Children’s Hospital Affiliated to Shandong University (No. SDFE-IRB/T-2024096). Written informed consent was waived due to the retrospective nature of this study. This study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

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