Intralesional Bleomycin Sclerotherapy for Low-Flow Vascular Malformations of the Head and Neck

Patients with clinically and radiologically confirmed low-flow vascular malformations of the head and neck were enrolled consecutively. Bleomycin was diluted to 3 mg/mL and injected intralesionally at multiple points, with a maximum of 15 mg per session and up to four sessions at three- to four-week intervals. Needle selection was guided by lesion depth, with ultrasound guidance used for deeper lesions. Lesion dimensions (length, width, depth) were measured by a single trained operator at each site; volume was calculated using the prolate ellipsoid formula (pi/6 x L x W x D), or by MRI-based volumetric segmentation for irregular multilocular lesions. Clinical response was graded using the modified Achauer scale. Adverse events were graded using CTCAE version 5.0, and peripheral oxygen saturation was monitored during and after each procedure.

• Bleomycin (Bleocel 15) (Drug): Intralesional injection of bleomycin diluted with normal saline to 3 mg/mL. Maximum 15 mg per session; up to four sessions at three- to four-week intervals; cumulative dose capped at 400 mg. Administered under local anaesthesia or conscious sedation, with ultrasound guidance for deep lesions.

Primary outcomes

• Percentage reduction in lesion volume [Baseline to 4 weeks after the final treatment session]: Lesion volume derived from three orthogonal dimensions using the prolate ellipsoid formula (pi/6 x length x width x depth) on ultrasound or MRI, or by MRI volumetric segmentation for irregular lesions. Percentage reduction calculated relative to baseline volume.

Secondary outcomes

• Incidence and severity of adverse events [From the first treatment session through 4 weeks after the final treatment session, up to 16 weeks]: Adverse events documented and graded using CTCAE version 5.0, including monitoring of peripheral oxygen saturation for pulmonary safety

Sex: All, ages: 1 Year to any

Inclusion Criteria:

* Age older than one year
* Clinically and radiologically confirmed low-flow vascular malformation of the head and neck
* No prior bleomycin therapy
* Medically fit for outpatient intervention

Exclusion Criteria:

* High-flow vascular malformation
* Pregnancy or lactation
* Documented hypersensitivity to bleomycin
* Pre-existing pulmonary or hepatic disease
* Bleeding disorder or current anticoagulant use
* Renal impairment (serum creatinine > 1.5 mg/dL or estimated glomerular filtration rate < 60 mL/min/1.73 m²)
* Active infection at or near the treatment site