In their review article on the hepatopulmonary syndrome, Lange and Stoller [1] provide an excellent discussion of possible pathogenic mechanisms and therapeutic options for intrapulmonary vascular dilatations associated with chronic liver disease. The authors' description of spring-coil embolization therapy as "disappointing" may, however, be overly pessimistic. As reported by the authors, the patient described by me [2] and by Felt and colleagues [3] had moderate improvement in room air PaO₂, from 38 mm Hg before embolization to 53 mm Hg after embolization. It must be emphasized that this change in oxygenation was accompanied by substantial improvement in dyspnea and a notable increase in exercise tolerance. After embolization therapy, the patient could walk approximately one quarter mile without supplementary oxygen, compared with only 12 feet before embolization.

Two other case reports of therapeutic embolization of pulmonary arteriovenous fistulae in patients with hereditary telangiectasia describe similarly efficacious results [4, 5]. Hatfield and Fried [4] reported improved oxygenation in a 47-year-old man whose room air PaO₂ increased from 35 mm Hg before embolization to 60 mm Hg after embolization. The patient experienced marked improvement in dyspnea and increased exercise tolerance without requiring supplementary oxygen [4]. Terry and colleagues [5] reported only modestly improved oxygenation in a 55-year-old man after balloon embolization. The patient's room air PaO₂ increased from 34 mm Hg before embolization to 57 mm Hg after embolization. These investigators [5] also noted marked improvement in the patient's respiratory symptoms, with exercise tolerance increasing from 10 stairs before the procedure to five flights of stairs after the procedure.

Although spring-coil embolization therapy cannot fully correct shunting from diffuse intrapulmonary vascular dilatations in patients with the hepatopulmonary syndrome, this procedure can reduce the number of large arteriovenous fistulae, thereby resulting in improved oxygenation. More importantly, this relatively noninvasive therapy offers patients with marginal respiratory status improvement of symptoms, increased functional capacity, and independence from supplemental oxygen.