Catheter Based Interventions
Use of heart catheterization either for balloon angioplasty or stenting for relief of pulmonary vein stenosis has yielded unsatisfactory results, with long term results being limited by disease recurrence.
Peng et al described one of the first studies describing the results of balloon angioplasty versus cutting balloon angiography ( Peng LF et al, 2010). While the authors were able to demonstrate hemodynamic and angiographic evidence of relief of pulmonary vein stenosis, there was no difference in relative gradient reduction between the 2 techniques. Cutting balloons were preferentially used in patients with higher pre-interventional pulmonary vein pressures and gradients. Freedom from reintervention in the entire cohort was 27% at 6 months and 15% at 1 year, while freedom from reintervention was shorter in those patients who received cutting balloon interventions (15% at 1 year) than those who received conventional angioplasty (23% at 1 year). Given the retrospective nature of the study, the variance in reason for catheterization and the bias modality based on disease burden, it is difficult to interrupt comparative results.
Balasubramanian et al compared outcomes following stent implantation for pulmonary vein stenosis ( Balasubramanian S et al, 2012). Stenting was most common in patients with heterotaxy and complex congenital heart disease, with the majority (62%) of patients having had prior pulmonary vein surgery. Pulmonary vein stenting was most common in the left veins (63%) and the median age of first pulmonary vein stent was 1.4 years.
Freedom from diagnosis of significant in-stent restenosis was 54% at 6 months and 37% at 1 year (B, 2012), while freedom from reintervention on the stented vein was 62% at 6 months and 42% at 1 year. In the cohort of 54 veins stented, occlusion occurred in 9 patients at median time of 4.2 months. In this cohort,
Direct comparisons of bare metal, covered and drug eluting stents is difficult as there were low numbers in the covered and drug elution cohorts; but importantly, stents with a luminal diameter of >7mm were associated with a longer freedom to reintervention, confirming previous reports (Tomita et al, 2003). Of note, many drug eluting stents are borrowed from coronary angiography and typically have a maximum diameter of 5mm, creating a distinct limitation in comparing stent types.
From the data available, it is unclear if those having a post interventional luminal diameter of > 7mm represents a distinct clinical cohort. The idea that intraluminal diameter is correlated with freedom from reintervention and potentially survival has been shown in other studies addressing pulmonary vein cross sectional area. Multiple studies have demonstrated that smaller pulmonary vein cross sectional area is associated with decreased survival ( Lo Rito et al, 2015), and this represents progressive disease that is more diffuse in nature, with a smaller upstream cross sectional area associated with decreased survival. Therefore, use of < 7mm stents may represent those patients with advanced progressive disease and these patients therefore require more frequent surveillance and are at high risk for re-stenosis.
Newer stent technology is currently permeating the pulmonary vein armamentarium (Bonello B et al 2015). There is currently a wide variety of drug eluting stents, and the use of bioabsorbable drug eluting stents may potentially have advantages, although their success in coronary literature is limited. Use of drug eluting balloons has been successful in niche areas of coronary and peripheral vascular disease; however the use of these in children with pulmonary vein stenosis is limited to case reports (Candy N et al, 2017; Latib A et al, 2012).
Complications from pulmonary vein angioplasty are described in the literature and the incidence of systemic embolic events is approximately 2.7%, which is higher than described for other congenital catheterizations. There is also a risk of non-embolic adverse events reported at approximately 25% at one single institution (Esch JJ et al, 2015). These adverse events included supraventricular tachycardia, pulmonary vein tearing, transient complete heart block, thrombus in the stent or pulmonary vein among others. Of note, access related complications were not included in this analysis.
Catheter based interventions, while frequently requiring reintervention due to restenosis, are essential as a bridge to transplant and helping to optimize for pulmonary vein surgery. There is also a role in palliation of patients not eligible for further interventions or transplant.
Peng et al described one of the first studies describing the results of balloon angioplasty versus cutting balloon angiography ( Peng LF et al, 2010). While the authors were able to demonstrate hemodynamic and angiographic evidence of relief of pulmonary vein stenosis, there was no difference in relative gradient reduction between the 2 techniques. Cutting balloons were preferentially used in patients with higher pre-interventional pulmonary vein pressures and gradients. Freedom from reintervention in the entire cohort was 27% at 6 months and 15% at 1 year, while freedom from reintervention was shorter in those patients who received cutting balloon interventions (15% at 1 year) than those who received conventional angioplasty (23% at 1 year). Given the retrospective nature of the study, the variance in reason for catheterization and the bias modality based on disease burden, it is difficult to interrupt comparative results.
Balasubramanian et al compared outcomes following stent implantation for pulmonary vein stenosis ( Balasubramanian S et al, 2012). Stenting was most common in patients with heterotaxy and complex congenital heart disease, with the majority (62%) of patients having had prior pulmonary vein surgery. Pulmonary vein stenting was most common in the left veins (63%) and the median age of first pulmonary vein stent was 1.4 years.
Freedom from diagnosis of significant in-stent restenosis was 54% at 6 months and 37% at 1 year (B, 2012), while freedom from reintervention on the stented vein was 62% at 6 months and 42% at 1 year. In the cohort of 54 veins stented, occlusion occurred in 9 patients at median time of 4.2 months. In this cohort,
Direct comparisons of bare metal, covered and drug eluting stents is difficult as there were low numbers in the covered and drug elution cohorts; but importantly, stents with a luminal diameter of >7mm were associated with a longer freedom to reintervention, confirming previous reports (Tomita et al, 2003). Of note, many drug eluting stents are borrowed from coronary angiography and typically have a maximum diameter of 5mm, creating a distinct limitation in comparing stent types.
From the data available, it is unclear if those having a post interventional luminal diameter of > 7mm represents a distinct clinical cohort. The idea that intraluminal diameter is correlated with freedom from reintervention and potentially survival has been shown in other studies addressing pulmonary vein cross sectional area. Multiple studies have demonstrated that smaller pulmonary vein cross sectional area is associated with decreased survival ( Lo Rito et al, 2015), and this represents progressive disease that is more diffuse in nature, with a smaller upstream cross sectional area associated with decreased survival. Therefore, use of < 7mm stents may represent those patients with advanced progressive disease and these patients therefore require more frequent surveillance and are at high risk for re-stenosis.
Newer stent technology is currently permeating the pulmonary vein armamentarium (Bonello B et al 2015). There is currently a wide variety of drug eluting stents, and the use of bioabsorbable drug eluting stents may potentially have advantages, although their success in coronary literature is limited. Use of drug eluting balloons has been successful in niche areas of coronary and peripheral vascular disease; however the use of these in children with pulmonary vein stenosis is limited to case reports (Candy N et al, 2017; Latib A et al, 2012).
Complications from pulmonary vein angioplasty are described in the literature and the incidence of systemic embolic events is approximately 2.7%, which is higher than described for other congenital catheterizations. There is also a risk of non-embolic adverse events reported at approximately 25% at one single institution (Esch JJ et al, 2015). These adverse events included supraventricular tachycardia, pulmonary vein tearing, transient complete heart block, thrombus in the stent or pulmonary vein among others. Of note, access related complications were not included in this analysis.
Catheter based interventions, while frequently requiring reintervention due to restenosis, are essential as a bridge to transplant and helping to optimize for pulmonary vein surgery. There is also a role in palliation of patients not eligible for further interventions or transplant.