To the Editor,

In our article on the recanalization rate of Amplatzer plugs versus coils for transcatheter closure of pulmonary arteriovenous malformations (PAVMs) in HHT, we reported on the retrospective evaluation of available patient data and imaging. As with all retrospective studies, it has the inherent limitations of nonrandomization and patient selection bias.

However, the patients who underwent a repeat pulmonary angiogram procedure did so for clinical reasons such as cyanosis or an increased amount of shunt [bubbles] on contrast echocardiogram or the presence of new PAVMs on a CT, and not just to evaluate the presence of recanalization. Many of these patients had multiple PAVMs embolized with coils or plugs in the same lung and therefore are acting as their own controls in a way.

Our study suggests that Amplatzer plugs have a significantly lower recanalization rate than coils. As we have mentioned in our paper, the true recanalization rate of both coils and plugs can only be accurately assessed in a prospective randomized controlled study.