Introduction: Invasive fetal cardiac intervention (FCI) for relief of right ventricular outflow tract obstruction has been performed with single-institution series reporting technical and physiologic success in promoting achievement of biventricular circulation after birth. No contemporary multi-center experience has been published. We have previously described creation of an international registry of cases presenting for possible FCI with the intention of compiling experience, technical aspects, and limited outcomes data. We queried this registry for all cases of pulmonary stenosis or atresia with intact ventricular septum (PS/PAIVS) in order to describe characteristics of fetuses at FCI and at birth, procedural details and pregnancy outcomes.
Methods: Maternal-fetal dyads referred from 2001-2016 for possible FCI are included. For this descriptive analysis, the database was queried for fetuses with a diagnosis of PS/PAIVS, details of anatomy, procedures, and outcomes; data was analyzed using simple descriptive statistics.
Results: A total of 35 maternal/fetal dyads undergoing pulmonary valvuloplasty at a median gestational age 26 weeks (range 23-30.3) are reported. Criteria for FCI varied in terms of tricuspid valve (TV) size, TV regurgitation (4 none, 3 mild, 7 moderate, 21 severe), or minimally patent pulmonary valve prior to FCI (15 fetuses). There were 5 procedure-related deaths and 6 preterm births. Among 24 live-born with known outcome, favorable physiologic status (biventricular circulation or 1.5 ventricle circulation) was reported for 22. Among the FCI patients, mean TV Z-score was -1.58 (SD1.8) at FCI and -1.03 (SD1.39) at birth, with an average improvement in Z-score of +1.25 suggesting catch-up growth of the TV after FCI.
Conclusions: Our retrospective data suggest a benefit to fetal therapy for PS/PAIVS, though procedure-related fetal loss was not trivial and FCI criteria are extremely variable. There is an urgent need for more uniform FCI criteria for fetuses with PS/PAIVS to be established. This will allow us to avoid unnecessary procedures and to expose only fetuses most likely to sustain substantial benefit to the risks involved.