Interventional approaches to head and neck vascular anomalies have evolved with our understanding of disease pathologic condition and advances in medical and surgical treatment. Embolization’s role in the disease management ranges from stand-alone treatment with curative intent to adjunctive or even palliative, depending on the lesion. This decision is best made through multidisciplinary collaboration among surgeons, interventionalists, and medical specialists. Finally, setting realistic expectations with the patient and family is a crucial step preceding any intervention. This article elaborates on the considerations influencing a given treatment plan and specific interventional strategy.
Key points
- •
Define the role of intervention with respect to an overall treatment goal.
- •
Use an interventional technique suited to the class of vascular anomaly.
- •
Manage patient and family expectations at the outset.
Introduction
Vascular anomalies (VAs) of the head and neck are diverse in terms of flow state, size, and location. , These factors influence a given VA’s symptomatology, functional and psychosocial impact. When treatment is indicated, the role of intervention must first be defined as either sole therapy with curative or palliative intent or adjunctive to surgery and/or medication. Interventional strategy itself is dictated by lesion characteristics, most importantly the flow state. Low-flow lymphatic or venous VAs are primarily treated by percutaneous sclerotherapy, whereas catheter-directed embolization applies more to high-flow arterial or arteriovenous VAs ( Table 1 ). Nevertheless, VAs represent a continuous spectrum, and so the treatment approach similarly demonstrates some degree of overlap.
| Agent | Mechanism of Action | Adverse Reactions | Notes |
|---|---|---|---|
| EVOH | Ethylene vinyl polymerizes into a solid cast as dimethyl sulfoxide (DMSO) solvent diffuses away | DMSO causes vascular necrosis in high concentrations; infuse at 0.1 mL/10 s | Patient emits foul odor as DMSO diffuses out of the body. Do not exceed 1.5 mL/kg EVOH per session |
| N-BCA glue | Cyanoacrylate polymerizes in ionic medium such as blood | Polymerization time cannot be precisely determined a priori. Therefore, nontarget embolization may occlude flow in undesired locations | Several factors affect n-BCA polymerization including ethiodized oil dilution, vessel flow, diameter, and tortuosity. Skilled use requires experience |
| PVA | Plastic beads travel with flowing blood until the vessel tapers and the particle lodges into an occlusive position | Small particles (<250 μm) penetrate deeper into the vascular bed and may result in ischemic necrosis of skin, nerve, or other tissues if off-target embolization occurs | Must be injected under conditions of free flow to prevent pressurization of the pedicle and subsequent passage of PVA though unseen anastomoses |
| Ethanol | Fibrinoid necrosis via protein denaturation, desiccation, and thrombosis |
|
Recommended dosage is 1 mL/kg or less. In high-flow VA, do not exceed 0.14 mL/kg/bolus and wait 10 min between bolus injections |
| Polidocanol | Endothelial cell death via calcium signaling and nitric oxide pathways |
|
Most data on use are from venous sclerotherapy although telangiectasia has also been successfully treated |
| Sodium tetradecyl sulfate (STS) | Detergent action dissolves lipids composing endothelial cell membrane |
|
Commonly used agent due to favorable side effect profile and efficacy, especially when foamed |
| Doxycycline | Inflammation, matrix metalloproteinase, and VEGF inhibition | Tissue necrosis in off-target embolization | Inexpensive. Commonly used in microcystic low-flow VA |
| Bleomycin | DNA degradation through inhibition of thymidine incorporation |
|
Recommended dosage is 0.5 IU/kg per procedure, not exceeding 15 IU. Lifetime maximum of 400 IU |
| OK-432 | Stimulation of host immunity | Successful trial in LM completed in 2007 but FDA approval lapsed. Further trials are currently ongoing to reintroduce agent into US market |
a Although all sclerosants may cause tissue necrosis if extravasation outside the confines of a VA occurs, ethanol tends to be the most severe.
b Air embolism is a risk with any foamed sclerosant, the most common agents being STS and polidocanol. Venous use predisposes to pulmonary emboli, whereas arterial (eg, telangiectasia) use in the head and neck predisposes to cerebral emboli.
Stay updated, free dental videos. Join our Telegram channel
VIDEdental - Online dental courses
