Lymphographic-Like Technique for the Treatment of Microcystic Lymphatic Malformation Components of <3 mm

Diagnosis

The mLM component of LMs was diagnosed on the basis of clinical and imaging features by an interventional neuroradiologist and maxillofacial surgeon, in our weekly multidisciplinary clinic. The diagnostic criteria were clinical (including vesicular maculopapular lesions on the skin surface, a soft-tissue mass with a rubbery hard texture, oozing of lymphatic fluid and/or hemorrhagic fluid, and/or pain and tenderness) and MR imaging was used to assess the extent of the lesions and the dimensions of the cysts. When imaging and clinical features were not conclusive, surgical biopsy was planned to confirm the diagnosis. However, no pretreatment surgical biopsy was required in this patient series.

Lymphographic-Like Technique

All procedures were performed by the same operator (G.S.) under aseptic conditions with the patients under general anesthesia. The position of the 22-ga needles inserted into the lymphatic malformation was checked by fluoroscopic and sonographic guidance, especially in deep or small lesions. When blood reflux was observed in the needle, the position of the needle was modified. Because the microcysts in this series were very small (<3 mm), we did not wait for lymphatic fluid reflux in the needle. Four-to-8 needles inserted into the microcystic component of the lymphatic malformations were used in each session, depending on the volume of mixture available based on the patient's weight. Each needle was connected to a pump with a line comprising a dead space of about 1.8 mL. Bleomycin was diluted as follows: 15 mg of bleomycin in 5 mL of saline and 3 mL of contrast to obtain 8 mL of mixture. This total volume of 8 mL was injected at each session in adults. Because a dose of 0.5 mg/kg per session was injected in children weighing <35 kg, the volume of mixture was determined as follows: 8 mL of mixture every 30 kg of weight. Each line was then filled with 1 mL of mixture, and the remaining line dead space was filled with saline. In low-weight babies, when the total volume of mixture was <4 mL, contrast medium diluted with saline (50%/50%) was added to obtain a volume of 4 mL to fill 4 syringes. A 10-cm-long gas bubble between the bleomycin mixture and the saline was used to avoid mixing the 2 solutions. Finally, the line was connected to a 10-mL electronic syringe pump filled with 1 mL of saline, and the infusion was administered at a flow rate of 0.7 mL/h. At the end of the injection, a low-dose CT scan was obtained to check diffusion of the mixture in the lymphatic malformation.

Posttreatment Care and Follow-Up

No compressive dressing was applied after completion of the sclerosant infusion. An intravenous infusion of 5 mg of dexamethasone sodium phosphate was routinely performed during the first hour after sclerotherapy to prevent excessive inflammation and its complications. The patient or family was instructed to evaluate sclerotherapy-related complications such as dermal discoloration, bleb formation, lymphedema, or necrosis occurring after discharge. Patients returned to the radiology outpatient clinic 1 month later for assessment of any sclerotherapy-related complications. When no complications were observed, a 1-month interval was observed between the 2 bleomycin injection sessions; at 3 months from the first sclerotherapy, patients were asked to undergo a follow-up MR imaging.

The result of infusion sclerotherapy was initially assessed by 3-month follow-up T2- and T1-weighted sequences in axial and coronal views. On the initial MR images, retrieved from the PACS, anatomic landmarks were used to measure the target microcystic lesion. Soft-tissue thickness was measured from the dermal surface to an interface between the lesion and underlying structures such as the muscular fascia or bony cortex (Fig 1). Posttreatment objective MR imaging evaluations were classified as no change (<10% decrease in size), minor improvement (10%–30% decrease in size), and objective improvement (>30% decrease). Clinical results were based on both the physician's physical examination and patient interview. Clinical results were graded as follows: poor subjective response to treatment, good response (reduction of subjective symptoms without decrease in lesion size), and excellent results (reduction of subjective symptoms with a clinically evident decrease in lesion size). Moreover, evaluation of the clinical response was based on the physician's examination at 12 months and was designed to assess cosmetic improvement (decrease in lesion size <10%, 10%–30%, and >30% on the physician's physical examination). Dysphagia was evaluated by the water test, and relief of pain and skin tension were assessed by the Faces Pain Scale. The decision to continue or discontinue treatment was based on this assessment.

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Fig 1.

Lateral (A) and anteroposterior (B) plain radiography during a sclerotherapy session in a patient with a diffuse maxillofacial microcystic lymphatic malformation. She had been previously treated by an operation. Before sclerotherapy, on the T1-weighted coronal (C) and axial (E) views, the lymphatic malformation extended into the maxillofacial soft tissues, with multiple small diffuse hypointense microcystic lesions measuring <3 mm. No macrocyst was identified. After 7 sclerotherapy sessions and a cumulative dose of 90 mg of bleomycin, T1-weighted coronal (D) and axial (F) views demonstrate dramatic reduction in the size of the lymphatic malformation. However, soft tissues of the face remain thickened due to fat transformation (hyperintense) of the cysts.

We assessed the final result of infusion sclerotherapy at the vascular anomaly clinic on the basis of a multidisciplinary consensus during the patient's follow-up visits, considering the objective and subjective results at each visit.

No further sclerotherapy was recommended by multidisciplinary consensus in cases with signs of deterioration, indicating ineffective treatment.

The initial and last clinical and MR imaging findings were compared to validate the infusion sclerotherapy.