Purpose: To evaluate blood ethanol concentrations immediately after percutaneous ethanol sclerotherapy of venous malformations (VMs).

Materials and methods: Thirty consecutive sclerotherapy procedures were performed for VMs in various anatomic sites. In a prospective study, the blood parameters monitored were ethanol plasma level (immediately after the procedure), plasma haptoglobin (Hp; before and after the procedure), and standard blood analysis including urea, creatinine, bilirubin, and lactic dehydrogenase (LDH) levels during the hospital stay.

Results: The mean amount of 94% ethanol injected was 19.7 mL (0.03-0.78 g/kg of body weight). The observed systemic ethanol levels ranged from 0 to 1.16 g/L (mean, 0.33 g/L, SD = 0.33). The relationship between the observed plasmatic ethanol level (ETOH plasma) measured immediately after the procedure and the maximum expected plasmatic ethanol amount (ETOH max) was linear and significant (correlation coefficient r = 0.91 for all lesions, r = 0.96 for lesions without visible venous drainage, r = 0.86 for lesions with visible draining veins, and r = 0.93 for lobulated VMs). Minimal changes were observed for indicators of hemolysis: macroscopic hemoglobinuria in five of 30, abnormal Hp level in seven of 30, and increase in LDH and increase in bilirubinemia in one case each.

Conclusions: Systemic ethanol contamination during sclerotherapy of VMs could be detected in 25 of 30 cases (83.3%). The plasmatic ethanol level was directly proportional to the amount of ethanol injected and not dependent on the VM morphology, venous drainage, or injection technique. Clinicians and interventional radiologists must be aware of this massive ethanol outflow during percutaneous sclerotherapy of VMs and its potentially serious systemic complications.