Hemangiomas and vascular malformations (VMs) in the head and neck regions have traditionally been referred to as ‘hemangiomas.’ Currently, the International Society for the Study of Vascular Anomalies (ISSVA) classifies conventional cavernous hemangiomas as VMs (1). VMs in the head and neck region account for ~40% of all VMs, with an incidence of 1:5,000 to 1:10,000(2). The treatment options for VM include surgery, sclerotherapy, and laser therapy (1). Usually, surgical resection cannot be performed without causing functional or aesthetic impairment and may only be suitable for small localized lesions. Therefore, sclerotherapy has become a valuable alternative to the surgical resection of VMs in the maxillofacial region (3). Compared with conventional liquid sclerosing agents, foam sclerotherapy has been reported to be more effective at low concentrations and in small doses, thereby reducing complications and enabling safe and effective treatment (4). Although there have been some reports (5,6) on the effectiveness of polidocanol sclerotherapy without foam for VMs in the maxillofacial region, to the best of our knowledge, no study to date has evaluated the effectiveness and safety of foam sclerotherapy using only foam polidocanol for VMs in the oral and maxillofacial region. The present study thus aimed to examine its therapeutic effectiveness in patients with oral VMs (OVMs).

A total of 16 patients, comprising 4 male and 12 female patients, underwent foam sclerotherapy with polidocanol. The mean age of the patients was 46.8 years (range, 9-80 years). Among the patients, 4 patients had OVMs on multiple sites in the oral and maxillofacial regions, while 12 patients had OVMs on a single site, resulting in a total of 22 sclerotherapy sites. The following sites were observed: A total of eight OVM sites were on the lips, six were on the tongue, six on the buccal mucosa, and one each on the masseter muscle and pharynx. Notably, the VMs were superficial apart from those in the pharynx and masseter area. The average number of polidocanol doses was four (ranging from one to nine doses). The treatment outcome was CR in 6 cases and PR in 10 cases; no patients were found to have SD or PD. Other than pain and swelling at the injection site, no severe side effects, such as circulatory dynamic fluctuations or skin necrosis, were observed in the patients. In addition, no adverse events, such as blood clots, were noted (Table I). Statistically and descriptively, no obvious differences were found in various factors, including age and the site of VM occurrence, by therapy evaluation (Table II).

Hemangiomas are relatively common in the maxillofacial regions. The majority of hemangiomas are considered vascular malformations that do not exhibit neoplastic proliferation of blood vessel-derived cells and cause local dysfunction, bleeding, and aesthetic issues (7). In 1982, Mulliken and Glowacki (8) examined the presence of endothelial cell proliferation in diseases previously considered as hemangiomas and performed a histopathological classification of these diseases. They classified conventional hemangiomas into two groups as follows: i) Those with proliferative and quiescent phases of endothelial cells and ii) those without proliferation of endothelial cells and with a normal cell cycle. Vascular malformations were further subclassified into arteriovenous, capillary, venous, and lymphatic. Currently, the ISSVA classifies ‘hemangiomas’ and ‘vascular malformations’ as separate disease entities (1).

The treatment for VMs in the oral cavity includes surgery, sclerotherapy, and laser therapy (1). Surgical resection can result in functional and aesthetic impairments. By contrast, sclerotherapy is a minimally invasive treatment option for vascular malformations that can be treated without causing functional or aesthetic impairment (3). Sclerosing agents damage vascular endothelial cells, causing thrombosis and subsequent fibrosis (7). Anhydrous ethanol, ethanolamine oleate, and polidocanol are frequently used as sclerosing agents (9). A previous study reported that anhydrous ethanol had the lowest recurrence rate and was the most effective sclerosing agent (10). However, several complications associated with anhydrous ethanol sclerotherapy have been reported, and these include tissue necrosis, peripheral nerve damage, cardiac arrhythmia, and pulmonary embolism (11). Monoethanolamine oleate has excellent thrombogenic potential but needs to be administered under fluoroscopic guidance, as leakage from the lesion can cause hemolysis and acute renal failure (5).

Polidocanol is a non-ionic surfactant that lyses the endothelial layer via absorption into the cell membrane (12). Polidocanol has been reported to be effective in ~90% of OVMs and can be used for sclerotherapy without unique administration methods with a limited number of complications (5). Although polidocanol is associated with relatively fewer complications than other sclerosing agents, Marrocco-Trischitta et al (13) reported cases of cardiac arrest when polidocanol was used in pediatric patients, suggesting the need for careful administration when used in children.

In the present study, all patients achieved CR and PR. However, multiple doses are necessary to achieve a sufficient response for extensive lesions. Therefore, multiple treatment cycles required for sclerotherapy with foam polidocanol are a vital drawback to consider. To minimize the number of sclerotherapy and achieve complete disappearance of the lesion, a possible treatment strategy would be to use sclerotherapy to reduce the VM to a size that does not compromise functionality and esthetics, followed by surgical intervention.

Foam sclerotherapy is a type of sclerotherapy wherein a sclerosing agent is mixed with air or carbon dioxide to form a froth. This technique was first used by McAusland (14) in 1939 to treat telangiectasias by shaking the sclerosing agent violently in a rubber stopper bottle to form a froth. In 1944, Orbach (15) reported foam sclerotherapy as an ‘air-block technique’. Compared with conventional liquid sclerosing agents, foam sclerotherapy has been reported to be more effective at low concentrations and in small doses, thus reducing complications and enabling safe and effective treatment (4). The smaller the foam formed, the more effective the treatment (16). According to the method described in the study by Tessari et al (6), a 1:4 ratio of hardener solution to air is the optimal mixture, and pumping >20 times does not affect foam formation.

Cabrera et al (17) reported that foam sclerotherapy with polidocanol and carbon dioxide was effective in 92% of patients and eliminated VMs in 36% of patients. Yamaki et al (18) conducted a randomized controlled trial of liquid sclerotherapy with polidocanol and ethanolamine oleate vs. foam sclerotherapy with polidocanol and ethanolamine oleate. They reported that foam sclerotherapy was significantly more effective than liquid sclerotherapy, and significantly fewer sclerosing agents were used in the former. Sclerotherapy with polidocanol foam effectively achieved CR and PR in patients without any severe complications. However, the present study did not include cases involving infants. Thus, further studies are required to explore the efficacy and safety of polidocanol sclerotherapy in infants.

Given that polidocanol causes inflammatory reactions in and around VMs, MRI imaging was not performed due to concerns that accurate evaluation would not be possible as it would detect not only the reduced venous malformation but also the surrounding inflammatory reactions. Future considerations should focus on refining image evaluation methods.

The limitations of the present study include the small sample size, the lack of pediatric indications and radiological evaluation of lesion size, and the lack of a defined follow-up period. In the future, the authors aim to increase the number of patients and conduct a multicenter collaborative study.

In conclusion, the present study evaluated the efficacy and safety of foam sclerotherapy with polidocanol for VMs in the oral and maxillofacial region, demonstrating it as an effective and safe treatment modality. However, further multicenter collaborative studies are crucial in order to obtain more comprehensive information.