Over-expansion of right ventricle to pulmonary artery conduits during transcatheter pulmonary valve placement

OBJECTIVES

To determine the safety and feasibility of over-expansion of right ventricle to pulmonary artery conduits during transcatheter pulmonary valve placement.

BACKGROUND

Transcatheter pulmonary valve placement is an alternative to surgical pulmonary valve replacement. Traditionally, it was thought to be unsafe to expand a conduit to >110% of its original size.

METHODS

This retrospective cohort study from two centers includes patients with right ventricle to pulmonary artery conduits with attempted transcatheter pulmonary valve placement from 2010 to 2017. Demographic, procedural, echocardiographic and follow-up data, and complications were evaluated in control and overdilation (to >110% original conduit size) groups.

RESULTS

One hundred and seventy-two patients (51 overdilation and 121 control) had attempted transcatheter pulmonary valve placement (98% successful). The overdilation group was younger (11.2 versus 16.7 years, p < 0.001) with smaller conduits (15 versus 22 mm, p < 0.001); however, the final valve size was not significantly different (19.7 versus 20.2 mm, p = 0.2). Baseline peak echocardiographic gradient was no different (51.8 versus 55.6 mmHg, p = 0.3). Procedural complications were more frequent in overdilation (18%) than control (7%) groups (most successfully addressed during the procedure). One patient from each group required urgent surgical intervention, with no procedural mortality. Follow-up echocardiographic peak gradients were similar (24.1 versus 26 mmHg, p = 0.5).

CONCLUSIONS

Over-expansion of right ventricle to pulmonary artery conduits during transcatheter pulmonary valve placement can be performed successfully. Procedural complications are more frequent with conduit overdilation, but there was no difference in the rate of life-threatening complications. There was no difference in valve function at most recent follow-up, and no difference in rate of reintervention. The long-term outcomes of transcatheter pulmonary valve placement with conduit over-expansion requires further study.

Is there a role for endovascular stent implantation in the management of postoperative right ventricular outflow tract obstruction in the era of transcatheter valve implantation?

BACKGROUND

The optimal management pathway for the dysfunctional right ventricular outflow tract (RVOT) is uncertain. We evaluated the long-term outcomes and clinical impact of stent implantation for obstructed RVOTs in an era of rapidly progressing transcatheter pulmonary valve technology.

METHODS

Retrospective review of 151 children with a biventricular repair who underwent stenting of obstructed RVOT between 1991 and 2017.

RESULTS

RVOT stenting resulted in significant changes in peak right ventricle (RV)-to-pulmonary artery (PA) gradient (39.4 ± 17.1-14.9 ± 8.3; p < 0.001) and RV-to-aortic pressure ratio (0.78 ± 0.22-0.49 ± 0.13; p < 0.001). Subsequent percutaneous reinterventions in 51 children to palliate recurrent stenosis were similarly effective. Ninety-nine (66%) children reached the primary outcome of subsequent pulmonary valve replacement (PVR). Freedom from PVR from the time of stent implantation was 91%, 51%, and 23% at 1, 5, and 10 years, respectively. Small balloon diameters for stent deployment were associated with shorter freedom from PVR. When additional children without stent palliation (with RV-to-PA conduits) were added to the stent cohort (total 506 children), the multistate analysis showed the longest freedom from PVR in those with stent palliation and subsequent catheter reintervention. Pulmonary regurgitation was well-tolerated clinically. Indexed RV dimensions and function estimated by echocardiography remained stable at last follow up or before primary outcome.

CONCLUSION

Prolongation of conduit longevity with stent implant remains an important strategy to allow for somatic growth to optimize the risk-benefit profile for subsequent surgical or transcatheter pulmonary valve replacement performed at an older age.

Edwards SAPIEN XT transcatheter pulmonary valve implantation: 5-year follow-up in a French Registry

OBJECTIVES

This study sought to investigate patient intermediate-term outcomes after transcatheter pulmonary valve replacement (TPVR) with Edwards SAPIEN valve.

BACKGROUND

The Edwards SAPIEN valve, initially designed for percutaneous aortic valve replacement, has been approved for TPVR in patients with dysfunctional right ventricular outflow tracts (RVOT), but only short-term follow-up has been reported.

METHODS

From 2011 to 2016, 62 patients undergoing successful TPVR using the SAPIEN XT valve were consecutively included into the study. Primary efficacy and safety endpoints were defined as freedom from valve-reintervention and freedom from infective endocarditis at last follow-up, respectively.

RESULTS

The primary efficacy outcome was met for 87.1% patients after a mean follow-up of 4.6 ± 1.8 years, corresponding to a freedom of reintervention at 5 years of 89% (95% CI 74.8-95.6%). Reinterventions were exclusively due to recurrent obstruction, no significant valvular regurgitation was observed. One case of infective endocarditis was reported, corresponding to a rate of 0.35% per patient-year (95% CI 0.01-2.00%). At 5 years, freedom from infective endocarditis was 98.4% (95% CI 89.1-99.8%). Six patients died or were transplanted due to advanced cardiac failure, without relationship with TPVR. In univariate analysis, reintervention was associated with young age, a smaller tube-graft, a higher pulmonary valve gradient after the procedure and a ratio of largest implanted stent diameter to invasive balloon conduit diameter over 1.35.

CONCLUSIONS

This study documents the mid-term safety and efficacy of the Edwards SAPIEN XT valve in patients with dysfunctional RVOT, and identifies a patient profile associated with an uncertain benefit-risk balance.

Transcatheter Pulmonary Valve Replacement With the Melody Valve in Small Diameter Expandable Right Ventricular Outflow Tract Conduits

OBJECTIVES

This study sought to evaluate the safety, feasibility, and outcomes of transcatheter pulmonary valve replacement (TPVR) in conduits ≤16 mm in diameter.

BACKGROUND

The Melody valve (Medtronic, Minneapolis, Minnesota) is approved for the treatment of dysfunctional right ventricular outflow tract (RVOT) conduits ≥16 mm in diameter at the time of implant. Limited data are available regarding the use of this device in smaller conduits.

METHODS

The study retrospectively evaluated patients from 9 centers who underwent percutaneous TPVR into a conduit that was ≤16 mm in diameter at the time of implant, and reported procedural characteristics and outcomes.

RESULTS

A total of 140 patients were included and 117 patients (78%; median age and weight 11 years of age and 35 kg, respectively) underwent successful TPVR. The median original conduit diameter was 15 (range: 9 to 16) mm, and the median narrowest conduit diameter was 11 (range: 4 to 23) mm. Conduits were enlarged to a median diameter of 19 mm (29% larger than the implanted diameter), with no difference between conduits. There was significant hemodynamic improvement post-implant, with a residual peak RVOT pressure gradient of 7 mm Hg (p < 0.001) and no significant pulmonary regurgitation. During a median follow-up of 2.0 years, freedom from RVOT reintervention was 97% and 89% at 2 and 4 years, respectively, and there were no deaths and 5 cases of endocarditis (incidence rate 2.0% per patient-year).

CONCLUSIONS

In this preliminary experience, TPVR with the Melody valve into expandable small diameter conduits was feasible and safe, with favorable early and long-term procedural and hemodynamic outcomes.

Clinical validity and relevance of accidental puncture or laceration as a patient safety indicator for children

PURPOSE

Accidental puncture or laceration (APL) has been endorsed as a patient safety indicator and is being used to compare hospital performance and for reimbursement. We sought to determine the positive predictive value (PPV) of APL as a quality metric in a pediatric population.

METHODS

We retrospectively reviewed all cases that met APL administrative criteria over 5years in a quaternary pediatric hospital system. Events were categorized as false positive (FP) or true positive (TP). TP cases were further categorized as "potentially consequential" or "inconsequential". The PPV of APL was calculated, and a z-test was used to provide 95% confidence intervals.

RESULTS

Of the 238 cases identified, 204 were categorized as TP (86%; 95% CI: 80%-90%). Thirty-four of these events (17%) involved injuries that were considered "inconsequential". True events that required repair were identified as "potentially consequential" (n=170). Thus, the PPV of APL was 71% (95% CI: 65%-77%). Extenuating factors such as adhesive disease or abnormal anatomy were present in 39% of TP cases. Thirty-four cases (14%) were categorized as FP because no documented injury was found.

CONCLUSIONS

A large proportion of APL events are either false or clinically irrelevant, thus questioning its usability as a patient safety indicator for children undergoing surgery.

TYPE OF STUDY

Retrospective review.

LEVEL OF EVIDENCE

IV.

Transcatheter pulmonary valve insertion, expanded use (beyond large conduits from the right ventricle to pulmonary artery), and future directions

Transcatheter pulmonary valve insertion is the most important advance in congenital interventional cardiology since atrial septal defect devices became commonly available 15 years ago. It has changed the way we look at a number of diverse diagnoses and changes how we plan, diagnose, operate, and follow-up patients. It has changed how we counsel families expecting a child that may benefit from it. Expanded use of the Melody® valve, outside its United States Food and Drug Administration approved indications, has helped numerous additional patients. The use of transcatheter pulmonary valve insertion in selected patients following surgical Gore-tex® bileaflet in valve right ventricular outflow tract reconstruction and those with a history of prior small homograft conduits will be discussed.