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Left ventricular assist device explantation after myocardial recovery
Left ventricular assist device (LVAD) treatment may lead to reverse remodeling in heart failure patients. Selected patients can recover heart function and be eligible for LVAD explantation. Surgical methods for explanting an LVAD have been reported using various surgical accesses and different degrees of retained device material. We report a surgical technique for achieving a complete pump removal, with an emphasis on the technical details of inflow and outflow pump cannula management.
Left ventricular assist device (LVAD) treatment and medical therapy promote reverse remodeling through unloading of the ventricular chamber and reversal of the heart failure phenotype . Reverse remodeling can sometimes result in functional myocardial recovery, with recovery from heart failure symptomatology and normalization of left ventricle structure . Several studies have described that, with appropriate patient selection, some patients with myocardial recovery can undergo LVAD removal with acceptable long-term survival .
We report our technique of LVAD explantation in a patient with myocardial recovery after transcatheter aortic valve replacement (TAVR) and percutaneous coronary intervention (PCI) during LVAD support.
Currently there are no guidelines for recovery assessment during LVAD support. Suggested criteria for weaning and explantation of an LVAD are based on echocardiographic, electrocardiographic, and hemodynamic studies (right heart catheterization), and metabolic parameters (cardiopulmonary exercise testing) with reduced or no LVAD flow measured at rest, peak exercise, or peak dobutamine.
The patient described here is a 64-year-old female admitted for coronary artery disease, with low flow (stroke volume 22 ml), low gradient, low ejection fraction (EF) of 10%, and aortic stenosis with ischemic cardiomyopathy (proBNP 6730 pg/mL).
Right heart catheterization showed a pulmonary artery pressure of 67/38 (48) mmHg, pulmonary capillary wedge pressure (PCWP) of 39 mmHg, and a cardiac index (CI) of 1.4 L/min/m2. On February 2016 she underwent implantation of a HeartMate II (HMII, Abbott, Chicago, IL) LVAD in order to support the failing ventricle that presented with severe systolic dysfunction. Surgery was complicated by LVAD pocket infection and bacteremia with methicillin-resistant Staphylococcus aureus (MRSA) infection that required multiple antibiotic therapy regimens. Infection became chronic, with pump involvement, and treatment was limited to telavancin therapy.
During LVAD support, the patient showed progressive reverse remodeling (EF 50%, left ventricular end diastolic diameter (LVEDD) 34 mm at 9000 rpm speed, proBNP 887 pg/mL) and in order to optimize the myocardial recovery, TAVR (26 mm CE Sapien 3 Valve, Edwards Lifesciences, Irvine, CA) was performed by a transfemoral route to treat aortic stenosis. PCI was additionally performed (bare metal stent in the left anterior descending [LAD] coronary artery) to treat residual coronary disease. After 10 months of LVAD support, the patient continued to experience myocardial recovery (CI 3.4L/min, PCWP 11 mmHg, EF 56.8%, LVEDD 40 mm at 6000 rpm speed) and because of these results she was scheduled for LVAD explantation.
1 - HMII pump isolation in the distal quarter of previous sternotomy (0:00)
The patient was prepped and draped in the usual sterile fashion. A 3 cm vertical incision was made in the left groin, and the left common femoral artery and vein were identified. After reopening the sternal skin incision in the distal quarter, the outflow graft and outflow elbow of the HMII were identified. The driveline was then identified and next this area was copiously irrigated with povidone iodine.
2 - HMII outflow graft management during LVAD explantation (1:36)
Subsequently, all wires were removed and the sternum was divided using an oscillating saw. Using electrocautery, the right sternal edge was mobilized from underlying adhesions. The outflow graft was densely adherent to the posterior table of the sternum and was dissected free up to within approximately 1 to 2 cm of the ascending aorta, removing a previous ringed Gore-Tex graft (W.L. Gore and Associates, Newark, DE, USA).
Next, the left hemisternum was dissected free from underlying adhesions and then the HMII speed was increased from 9000 rpm to 9600 rpm to unload the ventricle and prevent injuries during heart isolation. This dissection was then carried over the right ventricle anterior surface laterally until the pericardium was identified. The scar tissue along the diaphragm and the left costal margin was incised along the body of the pump down to the inflow elbow where, subsequently, the inflow cannula was identified. At this point, the patient was systemically heparinized.
Using the Seldinger technique, the patient was placed on cardiopulmonary bypass. A 15-French left common femoral arterial cannula and a 21-French long venous cannula were inserted using 5-0 Prolene purse-string sutures. The HMII was then stopped and the outflow graft was clamped. Once the patient appeared to be stable, the outflow graft very near to the ascending aorta was stapled multiple times with a TA 30 vascular stapler EndoGIA (Covidien, Medtronic, Minneapolis, MN). The proximal end was also stapled once and the graft was then divided.
3 - HMII inflow graft management and reconstruction of ventricular apex after device removal (3:36)
The driveline (as it exited laterally) was then sharply divided with the knife and the wires cut with wire cutters. At this point, the left ventricle apex and heart could then easily be brought into the midline of the wound. The patient was placed in Trendelenburg and the tie-band in the inflow cannula of HMII was removed. Using a gentle twisting motion any adhesions of the endocardium were then broken loose so the inflow cannula could be removed. The silastic sleeve of the HMII was clamped with a vascular clamp.
The pump outflow graft and driveline were then removed from the operative field. Using pledgeted 4-0 Prolene, multiple horizontal mattress sutures were placed beneath the silastic sleeve. The clamp was then removed and using 3-0 Prolene the silastic sleeve was sewn over and over, compressing it onto the surface of the remodelled LV apex. This was then all covered with BioGlue (CryoLife, Kennesaw, GA). The heart was then placed back in its normal pericardial location.
Normal ventilation was maintained throughout the procedure. The patient was gradually weaned from cardiopulmonary bypass without difficulty. Protamine infusion was begun and the femoral cannulas were removed. The sternum and groin were closed in standard fashion and all wounds were cleansed and covered with sterile dressings.
The driveline exit site was opened using electrocautery for approximately 2 cm proximally. Adhesions to the Dacron of the driveline were dissected free and it ultimately was removed from the tunnel. The exit site was partially re-approximated with interrupted sutures and packed with iodoform gauze.
Outcome
The patient was extubated on postoperative day (POD) 1 and successfully discharged home on POD 17 after an uneventful recovery on medical therapy. After 10 months, she remains New York Heart Association functional class II and her last EF was 55%.
From 2010 to 2014 we have explanted 22 LVADs in patients with nonischemic cardiomyopathy (n=18) and ischemic cardiomyopathy (n=4) supported on HM II (n=18), HeartWare (Medtronic, Minneapolis, MN, USA) (n=3), and C-pulse (CHF Solutions, Eden Prairie, MN, USA) (n=1) devices. Among these patients, 1 patient was transplanted, 2 were reimplanted, and 1 died. The remaining 18 patients did well post-explantation; the most recent EF was 38% with a LVEDD of 5.78 cm at 2.05 + 1.53 years (2 months to 4 years) follow up .
A recent systematic review analyzed outcomes after LVAD explantation in 11 studies (213 patients). Perioperative mortality rate was 9.2% and late mortality was 15%. The survival at 1, 5, and 10 years post-explantation was 91, 76, and 65.7%, respectively, with a lower rate of heart failure recurrence and LVAD reimplantation in patients supported with a continuous-flow versus pulsatile LVAD .
Discussion
Different surgical techniques have been described to achieve LVAD explantation and it is important to consider both extrapericardial and intrapericardial pump devices and the different degree of retained device material after explantation. For extrapericardial LVADs such as the HMII, our technique provides, through redo sternotomy, a complete removal of the device without using an intraventricular plug in the previous silastic sleeve. This technique is recommended when pump infection exists.
Otherwise, through a left subcostal incision, it is also possible achieve complete pump explant by ligating the outflow graft and occluding the ventricular sewing ring with a polytetrafluoroethylene plug or a titanium plug . Across a left subcostal incision, it is also possible to achieve inflow and outflow ligation. The inflow bend relief of the HMII is excised to allow ligation of the inner graft and retention of the inlet cannula. The pump housing is removed after similar ligation of the outflow graft .
Another technique uses a limited subxiphoid incision: the outflow graft is exposed and ligated and the driveline is then transected at the level of the skin. The option of leaving the pump in place and simply cutting the percutaneous driveline at the exit site has also been described .
For intrapericardial LVADs such as HeartWare (HVAD), the surgical approach could be performed through redo sternotomy, left thoracotomy, or bilateral thoracotomy. Outflow graft management is similar to that for the HMII and it is usually ligated with silk ties or excluded using a stapler. For inflow tract management, it is possible to remove the sutures securing the sewing ring and then remove the HVAD and sewing ring. The hole in the LV apex is closed by placating previously-passed purse-string sutures followed by reinforcement with a 2–0 continuous polypropylene suture in two layers .
Another technique is to leave the sewing ring in place and occlude the apical inflow with an individually manufactured titanium plug (Fittkau Metallbau GmbH, Berlin, Germany); then the ring screw is closed .
In conclusion, the “LVAD bridge to recovery” is a feasible prospect, and several surgical options are available to achieve device removal, with differing degrees of retained device materials. The technique selected must be tailored to the specific patient. Future studies could include investigating whether patients eligible for LVAD explantation continue to recover cardiac function or redevelop heart failure, and/or whether the addition of innovative therapies (pharmacologic and/or cell-based therapy, exosomes, particulate extracellular matrix, miRNA, gene transfer, etc) would help facilitate long-term recovery .
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None declared.
Authors
Michele Galloa, Jaimin R. Trivedia, Gretel Monreala, Emma J. Birksb, and Mark S. Slaughtera
Author Affiliations
a. Department of Thoracic and Cardiovascular Surgery, University of Louisville
b. Department of Cardiology, University of Louisville, Louisville, KY
Corresponding Author
Mark S. Slaughter, MD
Professor and Chair,
Department of Thoracic and Cardiovascular Surgery
University of Louisville
201 Abraham Flexner Way, Suite 1200
Louisville, KY 40202
Phone: 502-588-7600
Fax: 502-568-7601
Email: Mark.slaughter@louisville.edu
© The Author 2018. Published by MMCTS on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.
