This clinical trial aims to assess the safety and efficacy of microwave ablation in treating vascular malformations, including both venous malformations (VM) and arteriovenous malformations (AVM). Vascular malformations are abnormal clusters of blood vessels that can cause pain, swelling, and functional impairment, significantly affecting a patient's quality of life. Microwave ablation is a minimally invasive treatment that uses heat to shrink abnormal vessels, but its effectiveness and safety for these conditions need further investigation.

The trial will enroll 150 patients (100 with venous malformations and 50 with arteriovenous malformations), all of whom will undergo a single session of microwave ablation. Ultrasound guidance will be used during the procedure to precisely target the lesions, while MRI will be used for both preoperative and postoperative evaluations to assess lesion size and track changes over time.

The primary goals of the study are to determine whether microwave ablation can reduce lesion size and improve symptoms such as pain and swelling. Additionally, the study will monitor adverse events to evaluate the safety of the procedure, including any potential complications like infection, bleeding, or nerve injury.

Patients will be followed for 12 months, with MRI scans taken at 1 month, 3 months, 6 months, and 12 months after the procedure to evaluate lesion shrinkage and monitor for any recurrence. Clinical symptoms will also be assessed at these time points to track improvement.

This study could provide important data on the safety and efficacy of microwave ablation, potentially offering a less invasive treatment option for patients with vascular malformations.

Inclusion Criteria:

1. Patients with clinically diagnosed vascular malformations (venous malformations (VM) or arteriovenous malformations (AVM)) confirmed by MRI or ultrasound.
2. Presence of symptomatic lesions (pain, swelling, functional impairment, or ulceration) that require treatment.
3. Lesions that are amenable to microwave ablation based on preoperative clinical and imaging assessment.
4. Ability to provide informed consent or parental consent for minors (if applicable).

Exclusion Criteria:

1. Capillary malformations or congenital arteriovenous fistula.
2. Lesions that are too close to critical structures (e.g., major blood vessels or nerves) and cannot be safely treated.
3. Pregnancy or breastfeeding.
4. Severe coagulopathy or significant bleeding disorders.
5. Active infection at the treatment site.
6. Patients with severe uncontrolled systemic disease that could interfere with treatment or recovery.
7. Recent treatments (e.g., surgery, sclerotherapy, embolization) for the same lesion within the last 6 months.