Treatment of severe aortic stenosis by interventional techniques with implantation of a valve prosthesis in the stenotic native valve has become a viable clinical alternative.1–3 Significant paravalvular aortic regurgitation is among the most important limitations of interventional revalving techniques. 4,5 Precise positioning of the valve prosthesis is of paramount importance to prevent paravalvular leakage. A valve frame positioned too far into the left ventricle has been associated with significant aortic regurgitation. Balloon valvuloplasty of the implanted valve, use of a second valve prosthesis and snare traction to pull the frame to a more optimal aortic position, thereby reducing paravalvular regurgitation, have been described immediately after the revalving procedure.2,3,6 The radial force of the self-expanding frame of the CoreValve system (Medtronic, Inc., Minneapolis, Minnesota) may result in reduced paravalvular regurgitation with time.3–5 However, an increase in paravalvular regurgitation has been described in rare cases during follow up after implantation of the system. Dislocation of the valve prosthesis may be a possible reason. Case 1. An 86-year-old female with severe aortic stenosis (mean pressure gradient 53 mmHg, aortic valve area 0.5 cm2) presented to our institution. A computed tomography (CT) scan demonstrated an annulus diameter of 25 mm and severe calcification of the aortic valve (Agaston score 4145). The patient underwent an interventional aortic revalving procedure using a 29 mm CoreValve device. Fluoroscopy immediately after valve placement demonstrated an adequate position. The patient was hemodynamically stable with grade I aortic regurgitation by angiography. After 1 week, the patient developed increasing dyspnea and bilateral pleural effusions. Echocardiography and magnetic resonance imaging (MRI) demonstrated severe (grade III) paravalvular aortic regurgitation. Additionally, MRI indicated an unusually deep position of the valve prothesis. Due to an inability to stabilize the patient medically with recurrent pleural effusions after drainage, the decision was made to attempt interventional correction of the position of the valve prosthesis. The patient’s invasive pressure before the correction procedure was 125/28 mmHg. Her left ventricular end-diastolic pressure was 25 mmHg. Fluoroscopy demonstrated displacement of the frame towards the left ventricle by approximately 5 mm compared to immediately after the procedure. The waist of the frame had slipped almost to the calcified aortic annulus. Angiography confirmed severe paravalvular leakage (grades III–IV). Using right brachial artery access with a 7 Fr sheath, a 20 mm nitinol loop snare (Andramed/Reutlingen) was advanced towards the CoreValve prosthesis and used to grab the valvular frame at one of the delivery anchors. Traction of the frame with the snare using a force of approximately 100 N was started. The strong force resulted in a transient deformation of the valve frame (Figure 1) and an immediate increase in diastolic pressure. However, releasing the traction also resulted in an immediate drop in diastolic pressure. Under fluoroscopic surveillance, the valve frame was dragged for a total of 40 minutes. Using the external force and the force of the heart, the CoreValve prosthesis tilted and was able to be pulled in the direction towards the aorta by approximately 3 mm during this extended dragging procedure. The hemodynamic result was an increase in diastolic pressure to 45 mmHg, while the systolic pressure remained stable. The left ventricular end-diastolic pressure dropped to 18 mmHg. Angiography demonstrated a reduction in paravalvular leakage to grade I aortic insufficiency (Figure 2). The long forceful push of the sheet of the snare to close the snare demolished the end of the sheet. As a result, the metal end ring of the sheet could not be retracted and prevented opening of the snare. A second snare had to be used to loosen the ring and thereby allow opening of the snare which was occluded around the delivery anchor of the frame. After the procedure, the patient was able to mobilize without dyspnea and developed no recurrent pleural effusion. The procedure was performed with an 18 Fr femoral sheath in place to allow rapid placement of another device in the event that the initially placed device moved into the ascending aorta during the forceful traction maneuver. Discussion. Currently used interventional valve prostheses allow a variation in implant position of only a few millimeters. While deep placement towards the left ventricle results in paravalvular regurgitation, a placement too high towards the aorta increases the risk of complete valve frame mobilization into the ascending aorta during the final release process. Thus, interventional treatment of severe aortic stenosis relies on precise placement of the valve implant. Implantation of balloon-expandable valve prostheses like the Edwards SAPIEN valve involves a one-shot procedure. After implantation of the valve, its position cannot be corrected. The self-expandable nitinol frame of the CoreValve prosthesis allows correction of the frame position for an extended interval during the implantation procedure. Still, during the final release process, the valve frame may change position due to the intrinsic force of the self-expandable frame, resulting in a non-optimal prosthesis position. Paravalvular leakage is a potential limitation with current designs of valve prostheses.3–5 Further expansion of the valve frame using balloons designed for balloon valvuloplasty, implantation of a second valve prosthesis within the first valve prosthesis, as well as dragging of the valve frame with a snare have been described. These techniques have been successfully applied immediately after prosthesis implantation.3–6 In this case, traction of the valve frame was applied to a valve prosthesis implanted 2 weeks earlier and in which the valve prosthesis had slipped towards the left ventricle. Device migration after implantation should be considered as very rare. However, the radial force and the uneven diameter across the length of the nitinol frame of the self-expandable CoreValve prosthesis, together with the permanent motion of the adjacent left ventricle, may result in slight changes in device location. While dragging from the femoral access has been described, it involves use of the aortic arch as abutment for the snare. Thus, the aortic arch is pulled down. This may limit the applied dragging force. To increase the drag force, we used the snare with a right brachial access. This allowed direct application of drag force without the abutment of the aortic arch. While the procedure was successful in this case, there are certainly significant potential complications. These involve, in particular, sudden dislodgement of the valve prosthesis into the ascending aorta, arterial rupture, dissection and stroke.
1. Grube E, Laborde JC, Gerckens U, et al. Percutaneous implantation of the self expanding valve prosthesis in high-risk patients with aortic valve disease: The Siegburg first-in-man study. Circulation 2006;114:1616–1624.
2. Grube E, Schuler G, Buellesfeld L, et al. Percutaneous aortic valve replacement for severe aortic stenosis in high-risk patients using the second- and current third-generation self-expanding prosthesis: Device success and 30-day clinical outcome. J Am Coll Cardiol 2007;50:69–76.
3. Piazza N, Grube E, Gerckens U, et al. Procedural and 30-day outcomes following transcatheter aortic valve implantation using the third generation (18 Fr) revalving system: Results from the multicentre, expanded evaluation registry 1-year following CE mark approval: EuroIntervention 2008;4:242–249.
4. Zajarias A, Cribier AG. Outcomes and safety of percutaneous aortic valve replacement. J Am Coll Cardiol 2009;53:1829–1836.
5. Kallenbach K, Karck M. Percutaneous aortic valve implantation – contra. Herz 2009;34:130–139.
6. Ussia GP, Mule M, Tamburino C. The valve-in-valve technique: Transcatheter treatment of aortic bioprothesis malposition. Catheter Cardiovasc Interv 2009;73:713–716.
From the University Aachen, Medical Clinic I, Aachen, Germany. Benamin Rieck is employed by Medtronic. The authors report no conflicts of interest regarding the content herein. Manuscript submitted August 17, 2009, provisional acceptance given August 20, 2009, final version accepted September 10, 2009. Address for correspondence: Prof. Rainer Hoffmann, University Aachen, Medical Clinic I, Pauwelsstrasse, Aachen, 52074, Germany. E-mail: wilma.hoffmann@ t-online.de