Fontan fenestration closure and event-free survival

Objectives The purpose of the present study was to evaluate the association of open and closed Fontan fenestration status with event-free survival. Methods All patients who underwent a fenestrated Fontan procedure at our institution from January 1994 through June 2007 were reviewed. Patient information was obtained from the medical records. The patients were assigned to 1 of 2 study groups, open or closed, according to their most recent fenestration status. Clinically relevant morbid events were tabulated, and Kaplan-Meier event analysis was used to create event-free probability curves with log-rank comparisons. Results A total of 161 patients were classified as open and 51 as closed. The median interval to an event was 1.1 years (interquartile range, 0.1-3.3 years) after the Fontan procedure. The median interval to closure was 1.2 years (interquartile range, 0.7-3.3 years). The median interval to an event was 1.5 years (interquartile range, 0.1-4.6 years) in the closed group and 1.1 years (interquartile range, 0.1-3.3 years) in the open group. Event-free probability analysis revealed no significant difference between the 2 groups ( P = .15). The median follow-up arterial oxygen saturation was greater in the closed group (96.0%; interquartile range, 94.0%-97.0%) than in the open group (91.0%; interquartile range, 86.0%-95.0%; P