Congenital Heart Interventions

Transcatheter Recanalization of Atretic Pulmonary Veins in Infants and Children. Patel JD, Mandhani M, Gray R, Pettus J, McCracken CE, Thomas A, Bauser-Heaton H, Kim DW, Petit CJ.Circ Cardiovasc Interv. 2022 Jun;15(6):e011351. doi: 10.1161/CIRCINTERVENTIONS.121.011351. Epub 2022 Jun 21.PMID: 35727880 Review.   Take Home Points: Pulmonary vein stenosis is a complex disease process that includes anatomic vascular stenosis and myofibroblastic proliferation. Recanalization of atretic pulmonary veins is successful in the modern era with a low complication rate. Recanalized veins frequently become atretic again and long term outcomes in this patient population remain poor. Commentary from Dr. Ryan Romans (Kansas City, MO), section editor of Congenital Heart Disease Interventions Journal Watch:   Pulmonary vein stenosis (PVS) is a unique disease within the world of congenital heart disease in that it is not a purely vascular lesion (such as aortic coarctation or pulmonary artery stenosis). There has been limited success achieving durable outcomes following both surgical and transcatheter interventions. Aggressive myofibroblastic proliferation contributes to disease progression over time and, if untreated, can lead to the development of pulmonary vein atresia (PVA). Thus far there are no report on treatment of PVA in a large cohort.   A retrospective review of all pediatric patients with a diagnosis of PVS from 2008-2020 at Children’s Healthcare of Atlanta was performed. All CT angiograms and angiography was reviewed to confirm accuracy of specific vein involvement and progression of disease by two of the study’s authors. The degree of stenosis/atresia was defined by the previously described criteria as depicted in this diagram. Attempts at recanalization of PVA was made by the interventional cardiologist. Any vein that was not successfully recanalized was deemed a failure for the purposes of the study regardless of whether recanalization was attempted. A total of 131 patients underwent treatment for PVS during the study period, 61 (46.6%) of whom developed PVA of at least one pulmonary vein. These patients were compared with the 70 patients who did not develop PVA (control group). The only demographic differences between the groups were a lower birth weight (1.35 versus 2.35 kg), more likely single vessel versus multiple vessel disease (30% versus 60.7 percent), and shorter follow up (1.5 versus 2.9 years) in the PVS group. There was significant early mortality in both groups (78.6% survival at 1 year in PVA group, 74% in PVS) with persistent but lower rate of later mortality (70%, 67.5%, and 60.9% survival at 2, 5, and 10 years in PVA, 74%, 66.2%, and 66.2% in PVS). There was not a significant difference in survival between the two cohorts.     There were 97 total atretic pulmonary veins in 61 patients. The left upper pulmonary vein was most commonly affected, followed by the left lower pulmonary vein and then right upper pulmonary vein. There was an era affect in identification of pulmonary vein atresia with 11 diagnoses from 2008-2012, 30 from 2013-2016, and 56 from 2017-2020. 47/97 atretic veins were successfully recanalized. Again, there was a difference between eras with 0/11 from 2008-2012 recanalized, 8/30 (27%) from 2013-2016, and 39/56 (70%) from 2017-2020. Following recanalization, 20 patients underwent drug eluting stent implantation, 16 balloon angioplasty, 7 stent dilation, and 4 bare metal stent implantation. The adverse event rate was low-2 cases of transient heart block and 1 case of stent embolization. In follow up, 53.1% of recanalized veins remained patent at 6 months and 42.6% at 2 years.   This study shows that transcatheter recanalization of atretic pulmonary veins can achieve acute success with a very low complication rate. Interestingly, there was not a significant difference in mortality in patients with PVA versus those with PVS. The authors hypothesize that this may be due to the development of collateral drainage in slowly developing PVA. Additionally, recanalization has improved in recent years, and this may contribute to improved survival in the PVA atresia group. Lastly, this patient population at CHOA is routinely treated with systemic sirolimus in the modern era which may improve overall outcomes. The authors comment on the importance of the development of a PVS Program in the ongoing success in treating this patient population. Given the high rate of recurrence (only 20.6% of atretic veins were successfully recanalized and remained patent at follow up), these patients require close surveillance with CT angiography and repeated cardiac catheterizations.