Transcatheter pulmonary valve replacement
| Transcatheter pulmonary valve replacement | |
|---|---|
| Other names | TPVR, percutaneous pulmonary valve implantation (PPVI) |
| Specialty | Interventional cardiology |
| Uses | Congenital defects of the right ventricular outflow tract, failing artificial valves |
| Complications | Stent fracture, infective endocarditis |
| Other options | Open heart surgery |
| Outcomes | 92%-98% successful implantation[1] |
Transcatheter pulmonary valve replacement (TPVR), also known as percutaneous pulmonary valve implantation (PPVI), is the replacement of the pulmonary valve via catheterization through a vein. It is a significantly less invasive procedure in comparison to open heart surgery and is commonly used to treat conditions such as pulmonary atresia.[2][3]
Uses
[edit]TPVR can be used to repair congenital defects in the pulmonary valve or right ventricular outflow tract dysfunction, such as pulmonary atresia, Tetralogy of Fallot, or persistent truncus arteriosus.[4] TPVR can also be used to replace dysfunctional artificial heart valves.[1]
For those experiencing symptoms, TPVR is indicated when the right ventricular systolic pressure is above 60 mmHg and/or when there is moderate to severe pulmonary regurgitation.[4] For those not experiencing any symptoms, TPVR is indicated if there is severe right ventricular outflow tract narrowing and/or severe pulmonary insufficiency, with decreased exercise capacity, progressive right ventricular dilation, progressive right ventricular dysfunction, progressive tricuspid valve regurgitation, right ventricular systolic pressure above 80 mmHg, or cardiac fibrillation.[4]
For dysfunctional artificial conduits, TPVR immediately resolves pulmonary regurgitation and normalizes the right ventricular outflow tract gradient, and is associated with significant improvements in symptoms and improvements in long-term ventricular function.[1]
Contraindications
[edit]Active infection, central vein occlusion, coronary occlusion, and need for other surgeries such as for arrhythmia are contraindications for TPVR.[4][1]
If coronary compression (which impairs coronary blood flow) is observed with balloon dilation in the right ventricular outflow tract, TPVR is also contraindicated.[4] This test is performed to prevent potentially fatal complications, for which approximately 5% of candidates are at risk.[4]
TPVR is not recommended for tracts that are less than 16 mm[4] or more than 29 mm in diameter.[1]
Complications
[edit]There is a low incidence of major complications, which is likely due to pre-procedural assessments preventing individuals with unfavourable anatomy from undergoing the procedure.[5]
The most common complication is fracture of the stent frame.[4] This is seen in up to 30% of cases.[4] The majority of stent fractures are diagnosed by routine imaging and are not clinically relevant.[4] Stent fractures leading to obstruction of the right ventricular outflow tract is the most common reason for repeat intervention and can be treated with valve-in-valve procedures (placing a new valve inside the failed valve).[4] More severe fractures may require surgery.[4] Risk factors for stent fractures include younger age, smaller tract diameter, and position of the valve directly below the sternum.[4]
Tears or ruptures of the right ventricular outflow tract may occur during the procedure, especially if the tract is already heavily calcified.[4] This is reported to occur in up to 9% of procedures.[4] Most cases are manageable by using a covered stent and do not lead to severe bleeding.[4]
Infective endocarditis occurs at a rate of about 1%-3%.[1] Most cases do not directly impact the implanted valve, and most cases can be treated with antibiotics.[4] However, infective endocarditis can also cause valve explantation or sepsis, which can lead to death.[4]
Rare complications that may require urgent surgery include valve migration, valve embolization, pulmonary artery occlusion, pulmonary artery rupture, or coronary artery compression impeding blood flow.[4][5]
Death is rare, and is usually attributable to other comorbidities rather than from the implantation procedure itself.[4]
Procedure
[edit]Pre-procedural assessment
[edit]Several tests are performed before the procedure to assess whether the procedure is suitable for the individual and to record their anatomy in preparation for the procedure.[4][6] Ventricular function and size are assessed with an echocardiogram.[4] The right ventricle and the anatomy of the outflow tract, including any anatomical variations, are also assessed with cardiac magnetic resonance imaging.[4][6] The severity of the outflow tract defect or pulmonary regurgitation is assessed with Doppler ultrasonography.[4]
Operation
[edit]TPVR is a percutaneous procedure, meaning the device is brought into the body through the skin and into a vein. Patients are put under general anesthesia.[4] The heart is typically reached by passing through the femoral vein, jugular vein, or subclavian vein.[4] A balloon dilation test is performed first, to confirm that coronary compression will not occur and the procedure can continue.[4][6] Stent fractures can be prevented by using pre-stenting, using a bare metal stent before TPVR.[5] After the valve is implanted, balloon dilation is used to create the diameter of the valve.[6] At the end of the procedure, pressure is applied to the area to encourage hemostasis (stop bleeding).[6]
Recovery
[edit]Patients undergoing TPVR are typically ambulatory within 6 hours of finishing the procedure and can be discharged home within 24 hours.[6] As cardiopulmonary bypass is not required, a stay in the intensive care unit and an extended hospital stay are generally not needed.[6]
History
[edit]TPVR was developed as a less invasive alternative to other treatment options requiring open heart surgery, such as patch augmentation, replacing the native valve with an artificial heart valve, or using a valved conduit.[4] These surgeries typically require repeat surgeries to repair issues including pulmonary regurgitation, valve narrowing, kinking of the conduit, or calcification, leading to significant morbidity.[4]
The first TPVR was performed in 2000.[4][7] This device was further developed into the Melody transcatheter pulmonary valve by Medtronic.[4][6] The Melody device received approval from Health Canada in 2006 and from the US Food and Drug Administration (FDA) in 2010.[6] A similar device, the Edwards Sapien pulmonic transcatheter heart valve, produced by Edwards Lifesciences, first received FDA approval in 2015.[4][8]
The comparatively lower risks of TPVR and reduced need for reintervention compared to traditional surgical treatments has led to a paradigm shift favouring earlier treatment for right ventricular outflow tract defects, which were previously postponed due to the risks of traditional surgery.[1][9]
See also
[edit]References
[edit]- ^ a b c d e f g Wilson W, Osten M, Benson L, Horlick E (January 2014). "Evolving trends in interventional cardiology: endovascular options for congenital disease in adults". The Canadian Journal of Cardiology. 30 (1): 75–86. doi:10.1016/j.cjca.2013.11.006. PMID 24365192.
- ^ "Percutaneous pulmonary valve implantation for right ventricular outflow tract dysfunction". NICE. 23 January 2013. Retrieved 25 March 2019.
- ^ Jalal Z, Thambo JB, Boudjemline Y (November 2014). "The future of transcatheter pulmonary valvulation". Archives of Cardiovascular Diseases. 107 (11): 635–42. doi:10.1016/j.acvd.2014.07.046. PMID 25241221.
- ^ a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac ad ae af Ansari MM, Cardoso R, Garcia D, Sandhu S, Horlick E, Brinster D, et al. (November 2015). "Percutaneous Pulmonary Valve Implantation: Present Status and Evolving Future". Journal of the American College of Cardiology. 66 (20): 2246–2255. doi:10.1016/j.jacc.2015.09.055. PMID 26564602.
- ^ a b c Virk SA, Liou K, Chandrakumar D, Gupta S, Cao C (December 2015). "Percutaneous pulmonary valve implantation: A systematic review of clinical outcomes". International Journal of Cardiology. 201: 487–9. doi:10.1016/j.ijcard.2015.08.119. PMID 26313872.
- ^ a b c d e f g h i Qureshi AM, Prieto LR (June 2015). "Percutaneous pulmonary valve placement". Texas Heart Institute Journal. 42 (3): 195–201. doi:10.14503/THIJ-14-4276. PMC 4473610. PMID 26175629.
- ^ Bonhoeffer P, Boudjemline Y, Saliba Z, Merckx J, Aggoun Y, Bonnet D, et al. (October 2000). "Percutaneous replacement of pulmonary valve in a right-ventricle to pulmonary-artery prosthetic conduit with valve dysfunction". Lancet. 356 (9239): 1403–5. doi:10.1016/S0140-6736(00)02844-0. PMID 11052583. S2CID 38642691.
- ^ "FDA Approves Edwards Sapien 3 Transcatheter Heart Valve". Cardiac Interventions Today. Retrieved 21 December 2020.
- ^ de Torres-Alba F, Kaleschke G, Baumgartner H (October 2018). "Impact of Percutaneous Pulmonary Valve Implantation on the Timing of Reintervention for Right Ventricular Outflow Tract Dysfunction". Revista Espanola de Cardiologia. 71 (10): 838–846. doi:10.1016/j.rec.2018.05.001. PMID 29859895. S2CID 44167038.
