A Novel Percutaneous Technique for Left Ventricular Assist Device Deactivation Using a Left Atrial Appendage Occluder in the Outflow Cannula

Abstract

Reverse cardiac remodeling may occur in some left ventricular assist device (LVAD) recipients. Although considered the standard therapy, surgical device explantation with repeat sternotomy might be undesirable or very high risk. On the other hand, there are few data reporting minimally invasive percutaneous LVAD deactivation. We describe a case of a man with LVAD malfunction due to driveline fracture and left ventricular (LV) function recovery who had a Heart Mate II deactivated with a percutaneous technique using a left atrial appendage occluder (LAAO) positioned inside the outflow cannula. To the best of our knowledge, this the first report of LVAD deactivation with the fully recapturable LAAO device. We propose that the use of a LAA occluder to obstruct HM II outflow cannula is feasible and safe.

Left ventricular assist device (LVAD) support promotes left ventricle unloading and hemodynamic support in patients with end-stage heart failure. Reverse cardiac remodeling and ventricular function recovery have been observed in these patients, leading to LVAD explantation in 1–2% of cases reported in the Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS).¹ Although surgical device explantation is considered the standard therapy, it might be undesirable to expose the patient to another sternotomy and its possible operative complications. To avoid another surgical procedure, LVAD deactivation using minimally invasive techniques has been described. In this case report, we describe the first experience of Heart Mate II deactivation using a left atrial appendage occluder (LAAO) positioned inside the outflow cannula in a patient presenting LVAD malfunction due to driveline fracture and reverse cardiac remodeling.

Case Report

A 48 year old male patient with a HeartMate II (LVAD; Thoratec Corporation, Pleasanton, CA) implanted 3 years earlier due to idiopathic dilated cardiomyopathy, presented to the emergency department reporting alarm triggering of the device after a coughing crisis. It was noticed that the pump was off intermittently due to a driveline fracture, however the patient was asymptomatic and presented normal vital signs. An echocardiogram was performed and revealed improvement of left ventricular function. Left ventricular ejection fraction (LVEF) was 55% and left ventricular end-diastolic diameter (LVEDD) was 51 mm, while LVEF before LVAD implantation was 25% and LVEDD was 74 mm.

Repairing the driveline was not possible, and the patient remained stable and asymptomatic, despite the pump kept off for the next 2 days. New echocardiogram showed stable LV function, but LVEDD increased to 65 mm, possibly due to blood reflow through the outflow cannula. Since the patient presented reverse cardiac remodeling, the Heart Team decided not to change the device, but to inactivate it, by occluding percutaneously the outflow cannula. Surgical explantation was considered high risk, due to class 3 obesity and low center experience with LVAD explantation.

A cardiac computed tomography (CT) was performed to plan the procedure. Computed tomography–based outflow graft inner diameter of 15 mm (Figure 1) was used to select a LambreTM LAA Closure System (Lifetech, Inc, Boston Scientific, Marbourough, MA), with diameters of 18 mm in the umbrella and 24 mm in the cover. The degree of device oversizing was based on the experience of the operators with LAA occlusion procedures.

Figure 1.: Measurements of the outflow cannula landing zone (15 mm) shown by cardiac computed tomography.

The LambreTM system includes a self-expanding, fully recapturable, nitinol and polyester LAA occluder and its low-profile delivery sheath (8–10F). The occluder is composed by an umbrella with eight small hooks that engage into the LAA wall, and an articulated external cover, placed over the entry orifice of the LAA. The operators planned to anchor the umbrella to the inner face of the LVAD distal graft, and release the cover at the aortic side, closely resembling the concept of LAA occlusion with the same device.

The procedure was performed under conscious sedation and angiographic guidance. Vascular ultrasound was used for bilateral femoral artery puncture with 5F sheaths. Activated clotting time was adjusted to >250 s during the intervention. Aortography was obtained through a pigtail catheter (Figure 2). A second pigtail catheter and a 0.035″Radiofocus Glidewire were used to cannulate the graft. Then, the pigtail was used to advance an Amplatz Super Stifft (Boston Scientific, Marbourough, MA) 260 cm × 0.035″ wire to the distal portion of the outflow graft. Over the stiff wire, the 9F Lambre delivery sheath was advanced into the LVAD cannula. Following, the umbrella of the device was pushed and rolled out of the sheath, allowing the eight hooks for anchoring at the inner aspect of the graft, and then, the cover was unsheathed, occluding the LVAD graft’s aortic anastomosis. A final angiography showed limited flow to the LAAD outflow cannula (Figure 3).

Figure 2.: Aortography before occlusion of the outflow cannula of the left ventricle assist device.

Figure 3.: Control aortography, after device release, showed decreased flow to the outflow graft.

In the postoperative period, the patient was maintained on anticoagulation with unfractionated heparin. After 1 week of the first procedure, the patient underwent a driveline amputation procedure with the plastic surgery team, persisting without any cardiovascular symptoms. After 8 days of the procedure, echocardiogram revealed LVEF of 57% and LVEDD of 62 mm. He was discharged in the following days without major complications, on anticoagulation with Coumadin.

Although the patient remained asymptomatic after the procedure, 10 months later he presented pulseless ventricular tachycardia (VT) for 4 minutes. After defibrillation and return of spontaneous circulation, a new echocardiogram showed LVEF of 54% and LVEDD of 66 mm. After clinical stabilization, the patient underwent the implantation of an implantable cardioverter defibrillator (ICD). Before discharge, a new cardiac CT scan was performed and revealed no contrast filling in the outflow limb (Figure 4). He was discharged from the hospital without disabilities and remained asymptomatic after this event.

Figure 4.: Cardiac CT scan revealed no contrast filling in the outflow limb. This CT was performed before hospital discharge. CT, computed tomography.

Discussion

Although the INTERMACS registry shows that the rates of total recovery of heart function are low, these data are probably underestimated because few centers prospectively look for evidence of recovery, and heart failure medications are frequently not optimized after LVAD implantation.¹

Recent reports from LVAD centers using specific protocols revealed that the percentage of recovery can be much higher, and surgical removal of the device is the usual procedure in this scenario.² The Remission from Stage D Heart Failure,² a multicentric prospective study, evaluated a protocol for reverse cardiac remodeling after LVAD implantation associated with heart failure therapeutic optimization. In this study, 19 out of 40 patients met the explant criteria, and 12 out of these were submitted to a complete device removal through a sternotomy and another six patients were left with a residual inflow cannula without using cardiopulmonary bypass. One patient had the pump decommissioned percutaneously using an Amplatzer plug, and this patient had no difference in outcomes compared with the others undergoing traditional therapy.

The increasing number of recovered ejection fraction patients using LVAD led to emerging alternatives to inactivate the LVAD. A few techniques for accessing the device and performing its disable were described with favorable outcomes, including catheter-based device deactivation,^3–7 without the hazards of a new operation. Chrysant et al.³ was the first to describe a catheter-based device deactivation using a Maxi LD balloon to achieve complete occlusion of the outflow cannula as bridge to new surgery to LVAD replacement. Zeigler et al.⁴ were the first to describe a catheter-based procedure using 22 mm Amplatzer Vascular Plug II (St. Jude Medical) on the outflow cannula as a definitive procedure, without requiring a new sternotomy. Grinstein et al.⁵ described percutaneous decommissioning of Heartware using a 14 mm Amplatzer septal occluder deployed in the outflow graft in a patient with pump thrombosis who was not a candidate for device exchange. Pettit et al.⁶ described percutaneous withdrawal of HeartWare LVAD support, in which vascular Amplatzer plugs were deployed at both ends of the outflow graft.

In this case, the repositionable LAmbre device was selected to occlude the outflow cannula of a Heart Mate II LVAD based on the interventional cardiologist experience with other structural heart disease treatments. Procedural success was demonstrated by final angiography and the complete absence of blood flow inside the cannula was confirmed 10 months later, with a new cardiac CT scan.

After 10 months of LVAD deactivation, the patient remained without heart failure symptoms and preserved LVEF of 54%. However, he developed an episode of sustained VT. One possible explanation is the mechanical presence of the inflow cannula in the apex of the left ventricle, which could be a possible arrhythmogenic stimulus. The Remission from Stage D Heart Failure study reported a similar case, in which one of the patients who had the inflow cannula left presented VT. In that case, the researchers decided for a new operation to remove the device completely, and the patient did not present new VTs.² Differently, we decided to implant an ICD, since the patient remained obese and high surgical risk persisted to perform the device removal. Despite having proven to be a safe procedure, we still do not know the possible long-term consequences of percutaneous LVAD deactivation, and further studies are needed to better understand this type of intervention.

Conclusions

To the best of our knowledge, this is the first report of LVAD deactivation using the fully recapturable LAmbre LAAO device. We propose that using a LAAO to obstruct HM II outflow cannula is feasible, safe, and a good option for patients with heart failure recovery after LVAD who do not want to go through a new sternotomy or who have a high surgical risk.