Changes in pulmonary artery pressures during ethanol sclerotherapy for arteriovenous malformations: identifying the most vulnerable period

To evaluate the changes in pulmonary artery pressure (PAP) during ethanol embolization and to identify the most vulnerable period associated with cardiovascular collapse in patients with arteriovenous malformations (AVMs).Twenty-three patients (30 sessions) with AVMs were enrolled. PAP was measured at the following times: baseline (T(baseline)); immediately before (T(pre)), and after (T(post)) bolus injection of absolute ethanol; at the time of maximum mean PAP value during a session (T(highest-ethanol)); 10 min after final injection (T(final)); after restoration of spontaneous breathing (T(resp)); at extubation (T(extubation)); 30 min after extubation (T(extubation-30)(min)); and at the time of maximum mean PAP after patient resumed spontaneous respiration (T(highest-resp)). Nitroglycerin was infused (range 0.5-3 μg/kg/min) in all patients to attenuate the effect of ethanol on pulmonary vasoconstriction.The PAPs of T(highest-ethanol), T(resp), T(extubation), and T(highest-resp) were significantly higher than the corresponding values for T(baseline) and T(final) (all p0.05). The systolic and mean PAPs of T(highest-resp) were significantly higher than those at T(highest-ethanol) (both p0.05). In 24 sessions (80%), the highest mean PAP was detected during the recovery period.The greatest rise in PAP was noted during the recovery period in patients undergoing ethanol embolotherapy. Therefore, PAP monitoring and nitroglycerin infusions are recommended during the recovery period because early detection of an increase in PAP and prompt management may prevent detrimental complications.