Percutaneous pulmonary valve implantation in grown-up congenital heart disease patients: Insights from the Zurich experience

Rupture of a calcified right ventricle to pulmonary artery homograft by balloon dilation- emergency rescue by venus P-Valve

BACKGROUND

Percutaneous pulmonary valve implantation (PPVI) is a recognized alternative treatment to surgery for patients with dysfunctional right ventricular outflow tracts. Patient selection is essential to avoid serious complications from attempted treatment, such as rupture or dissection, especially of the calcified outflow tracts. We describe a case with an unexpected rupture of a calcified homograft valve and main pulmonary artery, which was treated successfully by emergency implantation of a self-expanding Venus P-Valve (Venus MedTech, Hangzhou, China) without the need for pre-stenting with a covered stent.

CASE DETAILS

A 13-year-old boy had two previous operations of tetralogy of Fallot, one a total repair and the other a homograft valved conduit for pulmonary regurgitation. He presented with dyspnea and severe right ventricular outflow tract obstruction (RVOTO) and had a calcified outflow tract and main pulmonary artery. In the catheter laboratory, a non-compliant balloon dilation resulted in a contained rupture of the conduit. The patient remained hemodynamically stable, and the rupture was treated with a self-expandable Venus P-Valve without the need for a covered stent combined with a balloon-expandable valve or a further surgical procedure.

DISCUSSION

Preprocedural evaluation with an inflating balloon is necessary to examine tissue compliance and determine suitability for PPVI. However, this condition is accompanied by a risk of conduit rupture. Risk factors of this complication are calcification and homograft use. These ruptures are mostly controlled with a prophylactic or therapeutic covered stent, with a low rate of requiring surgery. However, there are severe ruptures which lead to hemothorax and death. In the available literature, there was no similar reported case of conduit rupture, which a self-expandable Pulmonary valve stent has managed. It seems that fibrosis and collagen tissue around the heart, formed after open surgeries, can contribute to the control of bleeding in these cases.

CONCLUSION (CLINICAL LEARNING POINT)

The suitability of patients for the PPVI procedure should be examined more carefully, specifically patients with homograft and calcification in their conduit. Furthermore, conduit rupture might be manageable with self-expandable artificial pulmonary valves, specifically in previously operated patients, and the applicability of this hypothesis is worth examining in future research.

Infective Endocarditis Risk with Melody versus Sapien Valves Following Transcatheter Pulmonary Valve Implantation: A Systematic Review and Meta-Analysis of Prospective Cohort Studies

BACKGROUND

Transcatheter pulmonary valve implantation (TPVI) is an effective non-surgical treatment method for patients with right ventricle outflow tract dysfunction. The Medtronic Melody and the Edwards Sapien are the two valves approved for use in TPVI. Since TPVI patients are typically younger, even a modest annual incidence of infective endocarditis (IE) is significant. Several previous studies have shown a growing risk of IE after TPVI. There is uncertainty regarding the overall incidence of IE and differences in the risk of IE between the valves.

METHODS

A systematic search was conducted in the MEDLINE, EMBASE, PubMed, and Cochrane databases from inception to 1 January 2023 using the search terms 'pulmonary valve implantation', 'TPVI', or 'PPVI'. The primary outcome was the pooled incidence of IE following TPVI in Melody and Sapien valves and the difference in incidence between Sapien and Melody valves. Fixed effect and random effect models were used depending on the valve. Meta-regression with random effects was conducted to test the difference in the incidence of IE between the two valves.

RESULTS

A total of 22 studies (including 10 Melody valve studies, 8 Sapien valve studies, and 4 studies that included both valves (572 patients that used the Sapien valve and 1395 patients that used the Melody valve)) were used for the final analysis. Zero IE incidence following TPVI was reported by eight studies (66.7%) that utilized Sapien valves compared to two studies (14.3%) that utilized Melody valves. The pooled incidence of IE following TPVI with Sapien valves was 2.1% (95% CI: 0.9% to 5.13%) compared to 8.5% (95% CI: 4.8% to 15.2%) following TPVI with Melody valves. Results of meta-regression indicated that the Sapien valve had a 79.6% (95% CI: 24.2% to 94.4%, p = 0.019; R2 = 34.4) lower risk of IE incidence compared to the Melody valve.

CONCLUSIONS

The risk of IE following TPVI differs significantly. A prudent valve choice in favor of Sapien valves to lower the risk of post-TPVI endocarditis may be beneficial.

Right ventricular dilatation in patients with pulmonary regurgitation after repair of tetralogy of Fallot: How fast does it progress?

Objective

Pulmonary valve regurgitation (PR) and right ventricular (RV) dilatation are important residual findings after surgical repair of tetralogy of Fallot (TOF). We sought to describe the natural course of RV dilatation over time in patients with severe PR after TOF repair and to determine risk factors for quick progression of RV dilatation and dysfunction.

Methods

Data of 85 consecutive TOF patients with PR and RV dilatation, undergoing serial cardiovascular magnetic resonance (CMR) scans between July 2002 and December 2016 in two institutions, were retrospectively reviewed. The dataset was analyzed regarding right and left ventricular (LV) volume and function and potential risk factors of progressive RV dilatation.

Results

There was no significant increase in RV end-diastolic volumes (RVEDV_i) indexed body surface area (BSA) (median 150 [81-249] vs. 150 [82-260] mL/m²) and end-systolic volumes indexed for BSA (RVESV_i) (75 [20-186] vs. 76 [39-189] mL/m²) between the first and last CMR in the overall group. Similarly, there were no significant changes in LV volumes indexed for BSA (LVEDV_i 78 [56-137] vs. 81 [57-128] mL/m² and LV end-systolic volume index 34 [23-68] vs. 35 [18-61] mL/m2). Global function remained also unchanged for both ventricles. RVEDVi increased statistically significantly (≥20 mL/m2) in twenty patients (24%) from 154 mL/m² (87-237) to 184 mL/m² (128-260, P < 0.001). LV dimensions showed a similar trend with LVEDVi increase from 80 ml/m² (57-98) to 85 ml/m² (72-105, P = 0.002). Shorter time interval between repair and first CMR was the only risk factor predictive for progressive RV dilatation.

Conclusion

In the majority of patients with repaired TOF and severe PR, RV dilatation is unchanged during a follow-up of 3 years. RV dilatation seems to progress early after surgery and subsequently stabilize. RV dilatation significantly progresses in a subgroup of 24% of patients, with a shorter time interval since surgical repair.