Letters to the Editor Catheter-Based Device Closure of Fontan Fenestrations

I read with interest the article by Cowley et al. [1] on transcatheter closure of Fontan fenestrations with the Amplatzer. In the introduction section, they state that there are a variety of transcatheter methods to close the fenestrations and mention clamshell device, Rashkind ductal umbrella, coil, and Amplatzer septal occluder. I would like to draw the attention of the readers to our reported experience [2] in transcatheter inverted buttoned device occlusion of atrial defects producing right-to-left shunt associated with previously operated complex congenital cardiac anomalies. Four of the 12 patients in that report were Fontan fenestrations. Increase in arterial oxygen saturation, pulmonary-to-systemic flow ratio, and system venous saturation occurred without a significant change in heart rate, cardiac index, and systemic oxygen transport. At follow-up 12 6 5 months after the procedure, the arterial oxygen saturation remained improved for the group as a whole. In the four patients in whom we closed the Fontan fenestrations, the oxygen saturations remained high and no residual shunt was detected by Doppler studies. A larger experience with 22 patients, reported in an abstract form [3], confirms the previous observations [2]. I might take this opportunity to comment on other issues pertaining to device closure. The single-strand component of the inverted buttoned device goes onto the left atrial side of the baffle and is unlikely to interfere with the function of the atrioventricular valve such as that reported by Cowley et al. [1] with Amplatzer device. With the advent and wide use of staged Fontan concept, i.e., bidirectional Glenn initially, followed by diversion of the inferior vena caval blood into the pulmonary artery either by an intra-atrial tunnel or an extracardiac conduit (total cavopulmonary connection), we find it extremely unusual to require a fenestrated Fontan. Consequently, the need for closure of these fenestrations became less. Finally, the seminal observation that implantation of Amplatzer septal occluder is feasible, safe, and effective in occluding Fontan fenestration has already been made by Tofeig et al. [4], and the current report by Cowley et al. [1] adds little to our existing knowledge. However, the number of patient in the series by Cowley et al. [1] (n 5 12) is slightly larger than those of Tofeig et al. [4] (n 5 5). The complication rate is also higher in Cowley et al. [1]. In summary, inverted buttoned device, ignored by Cowley et al. [1], is a useful device in closing Fontan fenestrations, perhaps even with less probability of interference with atrioventricular valve function than Amplatzer. The need for performing fenestrated Fontans and consequently the necessity to transcatheter-occlude them is becoming less since the wide use of staged total cavopulmonary connection.