Demographic characteristics and estimated prevalence of Fontan-associated plastic bronchitis

Abstract

Plastic bronchitis (PB) is a poorly understood disease that can complicate any underlying pulmonary disease. However, it appears to most often occur in patients with surgically palliated congenital heart disease, particularly after the Fontan procedure. Few data exist about the prevalence and etiology of PB in this population. In an effort to establish data about prevalence, we conducted a retrospective study of an existing Fontan surgery database (n = 654) comprised of data, including sex, age at date of surgery, alive/dead status, New York Heart Association classification at last follow-up, right-ventricular end-diastolic pressure and pulmonary artery pressure before Fontan surgery, and the presence of a Fontan fenestration. An initial medical record review of 173 patients in the database who were followed at the University of Michigan identified seven patients with PB resulting in an estimated prevalence of 4 %. Subsequently, 14 % of 211 surveyed patients reported that they presently expectorate mucus or fibrin plugs (casts). Demographic and clinical variables did not differ between patients with or without possible PB. Collectively, these findings suggest that Fontan patients presently with PB may range from 4 to 14 %, indicating potential under-diagnosis of the disease. There were no remarkable physical or hemodynamic indicators that differentiated patients with or without possible PB. These data also highlight the need for more elaborate, prospective studies to improve our understanding of PB pathogenesis so that more definitive diagnostic criteria for this devastating disease can be established and its prevalence more accurately determined.

Fig. 1

a Schematic representation of the medical record review phase of the study. Of the 654 patients in the database, 26.5 % of them were followed-up at UMHS. Cross-referencing these records with ICD-9 and procedure codes 466, 33.22, and 33.23 for PB, flexible bronchoscopy, and rigid bronchoscopy, respectively, resulted in the identified 23 probable cases. Subsequent medical record review confirmed seven cases. b Schematic representation of the mail-survey portion of the study. After the application of exclusion criteria (see text), the survey was mailed to 528 patients. Of the 211 survey respondents, 1 % reported having been diagnosed with PB, whereas 14 and 24 %, respectively, reported having possible PB now or ever

Fig. 2

There was no difference in the number of male (26.6 %) and female (20.8 %) survey respondents who reported having possible PB ever (PB ever; p = 0.355) or having possible PB now (PB now; male 16.5 % vs. female 11.1 %, p = 0.290)

Fig. 3

Distribution of underlying CHD among surveyed primary-Fontan patients who reported having possible PB now (n = 31). Percentages do not total 100 because some patients had more than one condition. The surplus of patients with HLHS reflects the specialty of the University of Michigan’s Congenital Heart Program