Lymphatic malformations are non-cancerous masses of fluid-filled cysts resulting from the abnormal development of lymphatic vessels before birth. They can appear anywhere but are most common in the head and neck area, where they may cause discomfort, pain, or cosmetic concerns. A primary treatment is sclerotherapy, a minimally invasive technique using a chemical solution to reduce the malformation’s size and avoid larger surgical interventions.
How Sclerotherapy Treats Lymphatic Malformations
The goal of sclerotherapy is to close the abnormal lymphatic channels from the inside. This is achieved by injecting a chemical agent, a sclerosant, directly into the malformation’s cysts. The sclerosant irritates the endothelial cells that line the lymphatic vessels, triggering a localized inflammatory response. This inflammation causes the vessel walls to scar, a process called fibrosis.
As scar tissue forms, the walls collapse and adhere to one another, obliterating the space where fluid collected. Over the following weeks and months, the body’s natural processes reabsorb the trapped fluid, leading to a gradual reduction in the malformation’s size. The choice of sclerosant is tailored to the malformation’s characteristics, such as its size, location, and whether it is composed of large (macrocystic) or small (microcystic) cysts.
Commonly used sclerosants include:
- Doxycycline
- Bleomycin
- Ethanol
- Sodium tetradecyl sulfate
For instance, bleomycin is often selected for microcystic malformations, while the more potent ethanol may be reserved for specific cases.
The Sclerotherapy Procedure
The process begins with detailed imaging, such as an ultrasound or MRI, to create a precise map of the lymphatic malformation. This map allows the interventional radiologist to understand its depth, size, and relationship to surrounding tissues.
Most sclerotherapy procedures are performed under general anesthesia, especially for children or for large and complex malformations. In some cases involving smaller malformations in adults, local anesthesia with sedation may be sufficient.
Using live imaging, the interventional radiologist guides a thin needle directly into the malformation’s cysts. If the cysts are large, the radiologist may first aspirate, or drain, the lymphatic fluid. The sclerosant is then injected into the empty spaces, ensuring it makes direct contact with the vessel lining. The procedure’s duration can vary, ranging from under an hour to several hours for more extensive malformations.
Recovery and Post-Procedure Care
Following the procedure, a noticeable inflammatory response at the treatment site is expected. Patients experience significant swelling, bruising, and tenderness in the area where the sclerosant was injected.
Pain and discomfort are managed with over-the-counter pain relievers. To help manage the swelling, the use of compression garments may be advised, particularly for malformations located on the limbs. Patients are also given specific instructions regarding activity, which may include avoiding strenuous exercise for a short period.
It is important to monitor for specific signs. A fever could indicate a potential infection, and any skin blistering or ulcers at the injection site should be reported to the doctor promptly, as these complications require medical attention.
Treatment Efficacy and Long-Term Management
The primary objective of sclerotherapy is to achieve a significant reduction in the size of the lymphatic malformation and alleviate associated symptoms. It is important to understand that the treatment may not result in the complete disappearance of the malformation. The shrinking process is gradual, occurring over several weeks to months.
Achieving the desired outcome often requires a series of sclerotherapy procedures, typically spaced several months apart. The number of treatments needed can range from one to several, depending on the lesion’s size and complexity.
Follow-up appointments include imaging, such as an ultrasound, to monitor the reduction in the malformation’s size. This monitoring helps the care team determine the treatment’s effectiveness and decide if additional sessions are necessary.