Cryo-balloon angioplasty for pulmonary vein stenosis in pediatric patients

Transcatheter Recanalization of Atretic Pulmonary Veins in Infants and Children

BACKGROUND

Pulmonary vein stenosis is a progressive disease associated with a high rate of mortality in children. If left untreated, myofibroblastic proliferation can lead to pulmonary vein atresia (PVA). In our experience, transcatheter recanalization has emerged as a favorable interventional option. We sought to determine the acute success rate of recanalization of atretic pulmonary veins and mid-term outcomes of individual veins after recanalization.

METHODS

We reviewed all patients with PVA at our institution between 2008 and 2020 diagnosed by either catheterization or cardiac computed tomography. All veins with successful recanalization were reviewed and procedural success rate and patency rate were noted. Competing risk analysis was performed to demonstrate outcomes of individual atretic veins longitudinally.

RESULTS

Between 2008 and 2020, our institution diagnosed and treated 131 patients with pulmonary vein stenosis. Of these, 61 patients developed atresia of at least one pulmonary vein. In total, there were 97 atretic pulmonary veins within this group. Successful recanalization was accomplished in 47/97 (48.5%) atretic veins. No atretic pulmonary veins were successfully recanalized before 2012. The majority of veins were recanalized between 2017 and 2020-39/56 (70%). The most common intervention after recanalization was drug-eluting stent placement. At 2-year follow-up 42.6% of recanalized veins (20.6% of all atretic veins) remained patent with a median of 4 reinterventions per person.

CONCLUSIONS

Transcatheter recanalization of PVA can result in successful reestablishment of flow to affected pulmonary veins in many cases. Drug-eluting stent implantation was the most common intervention performed immediately post-recanalization. Vein patency was maintained in 42.6% of patients at 2-year follow-up from recanalization with appropriate surveillance and reintervention. Overall, only a small portion of atretic pulmonary veins underwent successful recanalization with maintained vessel patency at follow-up. Irrespective of successful recanalization, there was no detectable survival difference between the more recently treated PVA cohort and non-PVA cohort.

Systemic Sirolimus Therapy for Infants and Children With Pulmonary Vein Stenosis

BACKGROUND

Anatomic interventions for pulmonary vein stenosis (PVS) in infants and children have been met with limited success. Sirolimus, a mammalian target of rapamycin inhibitor, has demonstrated promise as a primary medical therapy for PVS, but the impact on patient survival is unknown.

OBJECTIVES

The authors sought to investigate whether mTOR inhibition with sirolimus as a primary medical therapy would improve outcomes in high-risk infants and children with PVS.

METHODS

In this single-center study, patients with severe PVS were considered for systemic sirolimus therapy (SST) following a strict protocol while receiving standardized surveillance and anatomic therapies. The SST cohort was compared with a contemporary control group. The primary endpoint for this study was survival. The primary safety endpoint was adverse events (AEs) related to SST.

RESULTS

Between 2015 and 2020, our PVS program diagnosed and treated 67 patients with ≥moderate PVS. Of these, 15 patients were treated with sirolimus, whereas the remaining patients represent the control group. There was 100% survival in the SST group compared with 45% survival in the control group (log-rank p = 0.004). A sensitivity analysis was completed to address survival bias using median time from diagnosis of PVS to SST. A survival advantage persisted (log-rank p = 0.027). Two patients on sirolimus developed treatable AEs. Patients in the SST group underwent frequent transcatheter interventions with 3.7 catheterizations per person-year (25th to 75th percentile: 2.7 to 4.4 person-years). Median follow up time was 2.2 years (25th to 75th percentile: 1.2 to 2.9 years) in the SST group versus 0.9 years (25th to 75th percentile: 0.5 to 2.7 years) in the control group.

CONCLUSIONS

The authors found a survival benefit associated with SST in infants and children with moderate-to-severe PVS. This survival benefit persisted after adjusting the analysis for survival bias. There were 2 mild AEs associated with SST during the study period; both patients were able to resume therapy without recurrence.

Treatment of Congenital and Acquired Pulmonary Vein Stenosis

PURPOSE OF REVIEW

Pulmonary vein stenosis (PVS) is a rare entity that until the last 2 decades was seen primarily in infants and children. Percutaneous and surgical interventions have limited success due to relentless restenosis, and mortality remains high. In adults, acquired PVS following ablation for atrial fibrillation has emerged as a new syndrome. This work will review these two entities with emphasis on current treatment.

RECENT FINDINGS

Greater emphasis on understanding and addressing the mechanism of restenosis for congenital PVS has led to the use of drug-eluting stents (DES) and systemic drug therapy to target neo-intimal growth. Frequent reinterventions are positively affecting outcomes. Longer-term outcomes of percutaneous treatment for acquired PVS are emerging. Treatment of congenital PVS continues to be plagued by restenosis. DES show promise, but frequent reinterventions are required. Larger upstream vein diameter predicts success for congenital and acquired PVS interventions. Efforts to induce/maintain vessel growth are important for future treatment strategies.

Adjunct Targeted Biologic Inhibition Agents to Treat Aggressive Multivessel Intraluminal Pediatric Pulmonary Vein Stenosis

OBJECTIVE

To evaluate the use of imatinib mesylate with or without bevacizumab targeting neoproliferative myofibroblast-like cells with tyrosine kinase receptor expression, as adjuncts to modern interventional therapies for the treatment of multivessel intraluminal pulmonary vein stenosis (PVS). We describe the 48- and 72-week outcomes among patients receiving imatinib mesylate with or without bevacizumab for multivessel intraluminal PVS.

STUDY DESIGN

This single-arm, prospective, open-label US Food and Drug Administration approved trial enrolled patients with ≥2 affected pulmonary veins after surgical or catheter-based relief of obstruction between March 2009 and December 2014. Drug therapy was discontinued at 48 weeks, or after 24 weeks of stabilization, whichever occurred later.

RESULTS

Among 48 enrolled patients, 5 had isolated PVS, 26 congenital heart disease, 5 lung disease, and 12 both. After the 72-week follow-up, 16 patients had stabilized, 27 had recurred locally without stabilization, and 5 had progressed. Stabilization was associated with the absence of lung disease (P = .03), a higher percentage of eligible drug doses received (P = .03), and was not associated with age, diagnosis, disease laterality, or number of veins involved. Survival to 72 weeks was 77% (37 of 48). Adverse events were common (n = 1489 total), but only 16 were definitely related to drug treatment, none of which were serious.

CONCLUSION

Survival to 72 weeks was 77% in a referral population with multivessel intraluminal PVS undergoing multimodal treatment, including antiproliferative tyrosine kinase blockade. Toxicity specific to tyrosine kinase blockade was minimal.

Reintervention Is Associated With Improved Survival in Pediatric Patients With Pulmonary Vein Stenosis

OBJECTIVES

The aim of this study was to evaluate survival following catheter intervention in pediatric patients with pulmonary vein stenosis (PVS).

BACKGROUND

Despite aggressive surgical and catheter intervention on PVS in children, recurrence and progression of stenosis can lead to right heart failure and death. Clinicians continue to seek effective treatment options for PVS.

METHODS

A single-center, retrospective study was performed including all patients <18 years of age who underwent catheter intervention (balloon angioplasty and bare-metal stent and drug-eluting stent insertion) on PVS. Endpoints included death, vein loss, and rate of reintervention.

RESULTS

Thirty patients underwent intervention (balloon angioplasty, n = 9; bare-metal stent, n = 5; drug-eluting stent, n = 16) at a median age of 6.4 months (4.3 to 9.9 months). Median follow-up duration was 30.6 months (77 days to 10.5 years). Fourteen patients (47%) died at a median of 2.0 months (0.4 to 3.2 months) following intervention. There was no association between DES placement and survival (p = 0.067). Reintervention (catheter or surgical) was associated with improved survival (p = 0.001), with a 1-year survival rate of 84% compared with 25% for no reintervention. Vein loss occurred in 34 of 58 (59%) veins at a median of 3.3 months (1.0 to 5.0 months). One-year vein survival was higher with DES implantation (p = 0.031) and with reintervention (p < 0.001).

CONCLUSIONS

DES implantation at first catheter intervention appears to be associated with improved vein survival but may not result in improved patient survival. However, reintervention appears to be associated with improved patient survival and vein patency, suggesting that despite mode of treatment, frequent surveillance is important in the care of these patients.