Second Valve Implantation for the Treatment of a Malpositioned Transcatheter Aortic Valve
- Volume 24 - Issue 9 - September 2012
- Posted on: 8/29/12
- 0 Comments
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Abstract: Background. Unfavorable immediate or delayed results after transcatheter aortic valve implantation (TAVI) may be a consequence of bioprosthesis malfunctioning, malpositioning, embolization, or degeneration. Deployment of a second valve within the first one implanted (TAVI-in-TAV) may be a potentially helpful therapeutic strategy. Methods. Six out of 412 patients undergoing TAVI had TAVI-in-TAV implantation for the treatment of a too high (n = 4) or too low position (n = 2) of the first implanted valve. Results. All TAVI-in-TAV procedures were successfully performed. The calculated valve area after second valve implantation was 1.6 ± 0.3 cm2 with a mean gradient of 7.3 ± 2.2 mm Hg. Residual aortic regurgitation (AR) was mild in 5 patients and moderate in 1. At mid-term follow-up (30-724 days) neither the mean valve area (1.47 ± 0.31 cm2), the mean gradient (7.5 ± 3.6 mm Hg; 3.0–13.0 mm Hg) nor the degree of AR had changed significantly. Conclusion. TAVI-in-TAV for correction of malpositioned or embolized valves is technically feasible and leads to favorable functional results during mid-term follow-up.
J INVASIVE CARDIOL 2012;24(9):457-462
Key words: aortic valve, heart valve prosthesis implantation, percutaneous, malpositioning, valve-in-valve
The prevalence of valvular heart disease increases in parallel to the aging of the population. As a consequence, degenerative aortic valve stenosis has become the most common valvular heart disease in developed countries, affecting 2%-7% of individuals over the age of 65.1,2 Once symptomatic, aortic valve stenosis is associated with poor prognosis and reduced survival.3 Transcatheter aortic valve implantation (TAVI) has emerged as an alternative to surgical aortic valve replacement among surgically high-risk patients.4
Despite the rapidly growing experience with this intervention, with more than 50,000 procedures performed so far, data on the incidence, cause, results, and long-term follow-up of transcatheter bioprosthesis-in-bioprosthesis implantation are scarce. This report focuses on the procedural and follow-up aspects of implantation of a second bioprosthesis within the first valve (TAVI-in-TAV), either during the initial or as a second intervention, to correct hemodynamically unfavorable results after the first TAVI.
Data from 412 high-risk surgical patients who underwent TAVI for treatment of severe aortic stenosis between July 2007 and November 2011 were prospectively collected. Before the intervention, all cases were reviewed by the local heart team, an interdisciplinary group formed by interventional cardiologists and cardiac surgeons, to define the best treatment approach and device selection for each patient. This decision was made based on a thorough evaluation that considered the clinical characteristics of the patient, the risk assessment based on the Euroscore and STS score, and the results of the preintervention screening investigation that comprised cardiac catheterization, transthoracic (TTE) or transesophageal echocardiography (TEE), computer tomography (CT), angiography of the aorta and iliofemoral vessels, carotid Duplex sonography, and pulmonary function tests.5 After the screening, 227 patients (55.1%) underwent transfemoral TAVI using a CoreValve device and 97 (23.6%) received an Edwards SAPIEN valve. The latter was implanted via transapical access in 83 patients (20.1%) and a CoreValve was deployed via trans-subclavian access in 5 patients (1.2%). Six patients (1.7% of the total) who had undergone transfemoral TAVI underwent implantation of a second prosthesis without retrieval of the first one (TAVI-in-TAV), either as bail-out (n = 5) or during an elective re-intervention procedure (n = 1). These 6 patients form the cohort of this report.
All procedures were performed under local anesthesia with conscious sedation and monitored anesthetic care. Transfemoral access was gained as previously described.6 The radiographic projection that delineated the cusps of the 3 native aortic valve leaflets in a single line defined the optimal C-arm angulation used for valve implantation. Initial balloon dilatation was performed in all cases under rapid pacing (160-200 beats/min) by means of a temporary pacemaker previously inserted via jugular vein into the right ventricle. All valves were deployed under fluoroscopic guidance. As the need for TAVI-in-TAV was defined, and in case the guidewire had been removed after implantation of the first valve, correct re-insertion of the guidewire through the implanted TAVI prosthesis was carefully monitored. The same implantation technique and the same prosthesis type and size were used in all cases but one, in which case a second larger device was chosen.
Postprocedural medication consisted of acetylsalicylic acid 100 mg/day and clopidogrel 75 mg/day for 6 months. Adverse events including cardiovascular mortality, myocardial infarction, stroke, bleeding, acute kidney injury, and vascular access-site and access-related complications were defined and summarized according to the Valve Academic Research Criteria (VARC).7 Clinical and echocardiographic follow-up were scheduled to be performed within 30 days and at 6 and 12 months after the procedure.
Baseline clinical characteristics and procedural results are presented in Table 1. Procedural success, defined as final stable placement of the second device, residual mean gradient less than 20 mm Hg, and absence of major cardiac and cerebral adverse events during the first 48 hours after implantation was achieved with all patients. Different mechanisms led to the need of a TAVI-in-TAV implantation for individual patients as described below.
Case 1. The first patient presented with severely calcified aortic leaflets requiring a stepwise dilatation of the valve. The passage of a 26 mm CoreValve prosthesis through the aortic valve was difficult, and during the deployment phase the valve dislodged cranially and was placed too high within the native annulus. As significant paravalvular aortic regurgitation (AR) was noted, postdilatation was performed in order to further expand the prosthesis and improve the degree of regurgitation. This led to embolization of the device into the ascending aorta. The valve was then snared to a higher position in the ascending aorta in order to avoid occlusion of the coronary ostia, and a second 29 mm CoreValve was successfully implanted into the aortic valve annulus with good result and only mild residual AR.
Case 2. A 26 mm CoreValve was implanted too low within the native aortic valve annulus, resulting in significant AR. Snaring of the bioprosthesis was attempted as a corrective measure, which led to dislodgment of the valve into the ascending aorta. A second 26 mm CoreValve prosthesis was then adequately implanted into the aortic annulus with a satisfactory final result.
Case 3. Severe angulations of the aortic arch caused distal dislodgment of a 29 mm CoreValve during deployment, resulting in severe AR. Attempts to snare and mobilize the prosthesis were unsuccessful. As a consequence, implantation of a second 29 mm valve was performed in appropriate position and improved the AR from severe to a moderate degree.
Case 4. The fourth case refers to an initially well-deployed 26 mm CoreValve prosthesis. However, one of the hooks connecting the valve to the delivery catheter remained attached to the catheter despite full deployment due to a high tension on the system. This led to a dislodgment of the valve into the ascending aorta while retrieving the delivery system. A second 26 mm CoreValve was successfully implanted in series, and the overall result was favorable.
Case 5 (Figure 1). This patient received primarily a 26 mm CoreValve. Despite slow and controlled stepwise deployment approximately 4 mm below the aortic annulus, cranial migration of the prosthesis was observed during the final release with embolization into the ascending aorta. The valve was then pulled back by means of a snare to avoid occlusion of the coronary ostia, and a second 26 mm CoreValve was implanted in adequate position.
Case 6. Implantation of a 29 mm CoreValve too deep relative to the native aortic annulus resulted in moderate paraprosthetic residual AR despite postdilatation. The patient was asymptomatic, but an increase in left ventricle diameters (51 mm to 57 mm systolic and 62 mm to 71 mm diastolic) and a hemodynamically significant AR were measured at echocardiography follow-up after 1 year. A second 29 mm CoreValve was implanted within the first prosthesis at a higher position and AR was reduced to grade I.
In-hospital outcome was complicated by major bleeding and acute renal injury in 1 patient, a major vascular complication in 1 patient, and a minor vascular complication in 1 patient. A definitive permanent pacemaker implantation was indicated in 2 out of 6 patients.
During mid-term follow-up (range, 30-724 days after intervention), 1 patient died of cancer 7 months after TAVI. Symptoms improved in 2 patients to New York Heart Association (NYHA) functional class I and in 4 patients to NYHA class II. Follow-up echocardiography revealed a calculated mean valve area of 1.47 ± 0.31 cm2 (range, 1.0-1.7 cm2) with a mean aortic transvalvular gradient of 7.5 ± 3.6 mm Hg (range, 3.0-13.0 mm Hg). Residual regurgitation was none in 2 patients, mild in 3 patients and moderate in 1 patient (Table 2).
TAVI-in-TAV was defined as the transcatheter insertion of a second bioprosthetic aortic valve within a previously implanted transcatheter bioprosthesis. This term is proposed to differentiate such procedures from those in which a percutaneous valve is implanted to treat a failed surgical bioprosthesis (valve-in-valve).
TAVI-in-TAV may be required either as bail-out or elective procedure, to deal with structural dysfunction, malpositioning, or embolization of the first implanted transcatheter valve. This strategy, however, has also been employed to treat other unusual conditions, such as the occurrence of a ventricular septal defect immediately after TAVI.8 Table 3 summarizes some possible indications for TAVI-in-TAV.