Treatment of cystic lymphatic vascular malformations with OK-432 sclerotherapy

Background: Cystic lymphatic vascular malformations are benign lesions that can cause disfigurement and functional impairment. Complete surgical resection is often difficult, and clinical recurrence is common. Sclerotherapy has been used as an alternative to excision. OK-432 is a lyophilized mixture of Streptococcus pyogenes and benzylpenicillin which, when injected into a lesion, has shown significant ability to reduce its size or obliterate it completely. Methods: The authors report a series of 12 patients treated in this fashion at the Vascular Anomalies Clinic, British Columbia Children's Hospital, between 1999 and 2004. All patients underwent imaging of the lesion: 10 had magnetic resonance imaging, one had a computed tomographic scan, and one had ultrasound examination. Six patients had macrocystic malformations (cysts >= 2 cm) and six had microcystic or combined lymphaticovenous malformations. Patients were treated with intralesional injection of OK-432. The position of the injection was confirmed by angiography and/or ultrasound in 10 cases. Response to treatment was assessed clinically. Results: All patients with macrocystic malformations had complete resolution or good response to treatment. None required any additional treatment. In contrast, those with microcystic or combined malformations responded poorly. All of these patients underwent subsequent excision without adverse consequences. The size and location of the lesion did not correlate with response to treatment. Seventy-five percent of patients experienced pyrexia. Local swelling is an expected phenomenon and must be anticipated, particularly for lesions near the airway. Conclusions: OK-432 is an excellent treatment for patients with macrocystic lymphatic malformations. However, it is ineffective for microcystic lesions.