CHDs with right ventricular outflow tract obstruction, including tetralogy of Fallot, pulmonary valve stenosis, complete transposition of the great arteries, double outlet of the right ventricle, perpetual truncus arteriosus, and atresia of the pulmonary arteries, generally require surgical right ventricular outflow tract reconstruction to relieve obstruction. ^{Reference Chaturvedi and Redington1} In contrast to the widely adoption of valved conduits in North America, right ventricular outflow tract enlargement with transvalvular/preserved annular patch remains the predominant technique employed in Europe, South America, and the Asia-Pacific region. ^{Reference Kaza2} Among patients treated with the latter approach, pulmonary regurgitation exists immediately after the procedure. Prolonged pulmonary regurgitation eventually leads to increased right heart overload and right heart enlargement, followed by right heart failure, atrial and/or ventricular arrhythmias, and even sudden death, ^{Reference Chaturvedi and Redington1,Reference Gatzoulis3} and the long-term survival is significantly worse than that of healthy individuals. ^{Reference Murphy4} Timely correction of severe pulmonary regurgitation may improve patients’ symptoms, reverse right ventricular remodelling, prevent irreversible cardiac dysfunction, and improve their survival. Surgical pulmonary valve replacement and transcatheter pulmonary valve replacement are currently the mainstay of treatment for such patients. ^{Reference Stout5,Reference Otto6} Although surgical pulmonary valve replacement and transcatheter pulmonary valve replacement have been shown to produce comparable perioperative mortality rate, intermediate-term mortality rate, and re-intervention rate, transcatheter pulmonary valve replacement is less invasive and associated with a lower rate of perioperative complications and shorter hospital stay. ^{Reference Ribeiro7} The 2020 European Society of Cardiology Guidelines for the Management of Adult Congenital Heart Disease state that transcatheter pulmonary valve replacement is preferred if the patient is anatomically suitable. At the same time, the availability of self-expanding transcatheter pulmonary valve replacement devices, such as the VenusP-Valve, has made it possible for the vast majority of patients with significantly dilated main pulmonary artery after patch repair to benefit from transcatheter pulmonary valve replacement. ^{Reference Baumgartner8} However, there remain a group of patients whose anatomical dimensions are beyond the treatment range of the largest commercially available transcatheter pulmonary valve replacement device (e.g. 36-mm VenusP-Valve). Since these patients usually have severe right ventricular enlargement and right ventricular dysfunction, redo open-heart surgery with surgical pulmonary valve replacement could carry a high risk of perioperative death and complications. In this regard, we have successfully attempted a hybrid approach for transcatheter pulmonary valve replacement using the self-expanding VenusP-Valve in two patients with severe pulmonary regurgitation and excessively large anatomy.

Case presentation

Patient 1

A 20-year-old male with tetralogy of Fallot underwent surgical repair in early childhood. He did not attend regular follow-up after the procedure. At the most recent visit, echocardiogram demonstrated severe pulmonary regurgitation and severe enlargement of right ventricle. Electrocardiogram suggested sinus rhythm and complete right bundle branch block with QRS duration of 156 ms. Cardiac magnetic resonance imaging corroborated the findings of echocardiogram and demonstrated significant dilatation of the main pulmonary artery. Based on cardiac magnetic resonance imaging measurements, right ventricular end-diastolic volume index was 230.38 ml/m² and right ventricular end-systolic volume index was 145.29 ml/m². Right ventricular ejection fraction was reduced (36.9%), while left ventricular ejection fraction was preserved (61.5%).

CTA demonstrated a pyramid-shaped (Type I) main pulmonary artery ^{Reference Schievano9} with no residual pulmonary valve leaflets, and measured the perimeter of pulmonary annulus at 111.9 mm (maximal diameter of 38.6 mm, mean diameter of 35.6 mm) (Figure 1). Because of the very dilated anatomy which prohibited sufficient oversizing even with the largest VenusP-Valve, he was deemed unsuitable for direct transcatheter pulmonary valve replacement, and heart team decision was to attempt a hybrid procedure with surgical plication of the main pulmonary artery first followed by transcatheter pulmonary valve replacement via the femoral vein.

Figure 1.

The preoperative pulmonary artery CTA of patient 1, shows the pulmonary valve annulus parameter measurements.

The patient was operated under general anaesthesia in the hybrid operating room. Baseline pulmonary angiography showed marked enlargement of main pulmonary artery and right ventricular outflow tract, with the minimal V diameter under balloon sizing of 37.6 mm (Supplementa Fig. 1) and 38.3 mm (Supplementa Fig. 2) on right and left anterior oblique view, respectively. Simultaneous coronary angiography at maximal balloon inflation also confirmed the absence of left coronary artery compression. Subsequently, main pulmonary artery was accessed through median sternotomy, with heart beating and no cardiopulmonary bypass support. The anterolateral aspect of main pulmonary artery was plicated at the sinotubular junction through a 5-needle strap-and-buckle suture to create a narrowing for transcatheter valve anchorage. Then pulmonary angiography was repeated, and demonstrated a reduced diameter of 27.1 mm at the site of plication (Figure 2). A 34-mm VenusP-Valve (VenusMedtech, HangZhou, China) was selected and successfully implanted via the right femoral vein. Postprocedural angiography showed optimal device positioning and the absence of residual pulmonary regurgitation. Postoperat CTA showed that the valve was well positioned and had a normal morphologic deployment (Figure 3). Recovery was uneventful and he was discharged at postoperative day 4. At 6-month follow-up, he was asymptomatic and had no infection, arrhythmia, bleeding or other complications. Echocardiography showed well-functioning prosthetic pulmonary valve with no central or paravalvular leak, and favourable right ventricular reverse remodelling (diameter reduced from 35 mm to 24 mm).

Figure 2.

Repeated pulmonary angiography after the procedure of partially fold and reduce the diameter of the MPA of patient 1.

Figure 3.

Postoperat CTA of patient 1, shows that the valve was well positioned and had a normal morphologic deployment.

Patient 2

The patient was a 32-year-old male who had undergone surgical repair of tetralogy of Fallot in early childhood, and became symptomatic 2 years ago with decreased activity tolerance and chest tightness. At the present visit, echocardiogram suggested severe pulmonary regurgitation with a very dilated right heart; electrocardiogram showed sinus rhythm and complete right bundle branch block with and a QRS duration of 176 ms. Routine cardiac magnetic resonance imaging showed severely dilated right ventricle and main pulmonary artery . Right and left ventricular ejection fraction was 39.6% and 59.0%, respectively. And right ventricular end-diastolic volume index and right ventricular end-systolic volume index was measured at 208.06 ml/m² and 125.52 ml/m², respectively.

CTA showed a cylindrically-shaped (Type II) main pulmonary artery ^{Reference Schievano9} which was severely dilatated. The perimeter at proximal main pulmonary artery /pulmonary annular level was 112.0 mm (maximal diameter 38.7 mm, mean diameter 35.6 mm) (Figure 4). Bilateral coronary arteries were distant from the pulmonary trunk.

Figure 4.

The preoperative pulmonary artery CTA of patient 2, shows the pulmonary valve annulus parameter measurements.

The same hybrid approach as for patient 1 was employed. Baseline pulmonary angiography via the femoral vein showed very large main pulmonary artery with diameter at proximal main pulmonary artery of 37.6 mm, (Supplementa Fig. 3), thus balloon sizing was not performed. Subsequently, the surgical team proceeded with median sternotomy to plicate main pulmonary artery and prepare for possible transfer to surgical intervention. Plication was achieved with 5 sutures at proximal main pulmonary artery without cardiopulmonary bypass support. Afterwards, pulmonary angiography was performed again which showed a narrowing at proximal main pulmonary artery with diameter of 29.1 mm (Figure 5). Then the largest 36-mm VenusP-Valve (VenusMedtech, HangZhou, China) was successfully implanted via the right femoral vein. The patient recovered rapidly after the operation, and there was no complications at 30-day follow-up. Echocardiogram at follow-up showed significantly reduced right ventricular diameter (from 31 × 59 mm to 26 × 38 mm), and the prosthetic pulmonary valve functioned well without any central or paravalvular regurgitation. Postoperative CTA demonstrated a well-seated VenusP-Valve with good expansion (Figure 6).

Figure 5.

Repeated pulmonary angiography after the procedure of partially fold and reduce the diameter of the MPA of patient 2.

Figure 6.

Postoperat CTA of patient 2, shows that the valve was well positioned and had a normal morphologic deployment.