Jalal Z, Valdeolmillos E, Malekzadeh-Milani S, Eicken A, Georgiev S, Hofbeck M, Sieverding L, Gewillig M, Ovaert C, Bouvaist H, Pillois X, Thambo JB, Boudjemline Y.
Circ Cardiovasc Interv. 2021 Mar 17:CIRCINTERVENTIONS120009707. doi: 10.1161/CIRCINTERVENTIONS.120.009707. Online ahead of print.
Take Home Points:
- Folding the ends of the Melody valve stent leads to a shortened overall stent valve length that can allow for placement in more challenging or complex RVOTs.
- This modified valve was implanted with excellent procedural outcomes of reduced RVOT gradient and minimal pulmonary insufficiency.
- Mid term outcomes are favorable and consistent with unaltered Melody valve results in terms of valve failure (due to stenosis or regurgitation) and infective endocarditis.
Commentary from Dr. Ryan Romans (Kansas City, MO), section editor of Congenital Heart Disease Interventions Journal Watch:
Transcatheter pulmonary valve replacement (TPVR) is a now widely available option for the treatment of dysfunctional right ventricular outflow tracts. The Melody valve (Medtronic, Minneapolis, MN) and Sapien XT and S3 valves (Edwards Lifesciences, Irvine, CA) are both now FDA approved for this indication. In order to safely implant the valves, there needs to be an adequate landing zone to accommodate the length of the valved stent. If the valve is placed too proximal, there is the risk of ventricular arrhythmias or ventricular embolization. If the valve is placed too distal, there is the risk of branch PA obstruction. A standard Melody valve length ranges from 24.6-28.8 mm depending on the valve diameter. The Sapien XT length is 14.3-19.1 mm depending on the valve diameter (the Sapien S3 did not receive FDA approval for TPVR until 2020 and hence was not discussed in this article). This group described a technique where they folded the Melody valve stent extremities to shorten the total valved stent length to allow for placement in challenging RVOTs. They were able to achieve Melody valve lengths at 22 mm of 20.9 mm by folding one end and 16.7 mm by folding both ends. In this study, Dr. Jalal and his co-authors report on the midterm outcomes of these valves.
A total of 49 patients from 7 European centers underwent successful TPVR with a from April 2012 to June 2018 with a “folded Melody valve.” The majority of these patients’ (68%) underlying anatomy was a tetralogy of Fallot variant. The primary indication for TPVR was pulmonary stenosis in 39%, pulmonary regurgitation in 22%, and mixed disease in 39%. The patient population had native/patch RVOTs in 31%, RV to PA homografts or conduits in 47%, and bioprosthetic valves in 22%. The primary indication for using the folded valve technique was a short RVOT in 57%, though the authors also report using this in bioprosthetic valves (done to minimize stent protruding into the RV and ensuring the entire stent valve apparatus is protected by the bioprosthetic valve apparatus to minimize risk of stent fracture), in situations where a shorter stent would avoid coronary artery compression, prevention of retrosternal compression, and to increase the devices outer diameter. RVOT presenting was performed in 89% of patients with a stent length of 32 +/- 6.8 mm. The authors were able to achieve reductions in the RV to PA gradient (~35 mmHg to ~12 mmHg), RV systolic pressure (~60 mmHg to 41 mmHg), and RV:Aorta ratio (0.68 to 0.38). Trivial pulmonary regurgitation was seen post procedure in 10% of patients with the remaining patients having no pulmonary regurgitation.
Follow up data was available for 47/49 patients with a median follow up duration of 28 months (range 4-80). At the time of last follow up, transthoracic echocardiography showed a mean RVOT gradient of 15 +/- 12 mmHg and RV pressure of 35.8 +/- 15.6 mmHg.There was trivial pulmonary regurgitation in 2 patients with the remainder having none. Three patients underwent reintervention for valve related complications (2.1% per patient per year incidence). Two patients developed infectious endocarditis (1.4% per patient per year) with an increased pressure gradient across the Melody valve. One patient was able to be treated percutaneously after antibiotic treatment (balloon angioplasty followed by Melody valve in valve implantation 3 years later). The other required surgical explant after antibiotic treatment. A third patient developed Melody valve stenosis at 24 months without an obvious etiology and underwent Melody valve in valve implantation.
Mid term outcomes of TPVR using the folded Melody valve technique are favorable with preserved valve function and no increased risk of infective endocarditis compared with the unaltered Melody valve (2-3%). Since the Sapien valve is now available, there is a decreased need to Fold the Melody valve given the shorter length of the Sapien. However, the smallest Sapien valve is 23 mm. Given this, the folded Melody valve technique is still a good option for patients with smaller conduits (14-19 mm). These mid term results are encouraging that this technique does not significantly alter the valve durability.
- Photo showing the process of folding the Melody stent valve on a 10 mL syringe.
- Both ends of the stent have been folded, shortening the length.
- Shortened valve on the Ensemble delivery system.