Left Ventricular Assist Device Insertion Periprocedural Care

Updated: Jul 06, 2016
  • Author: Craig H Selzman, MD, FACS; Chief Editor: Karlheinz Peter, MD, PhD  more...
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Periprocedural Care

Preprocedural Planning

As a general note, the success of a left ventricular assist device (LVAD) implantation procedure depends on more than just technique. Judicious preoperative evaluation and preparation must be combined with vigilant postoperative management of both the usual issues encountered in the intensive care unit (ICU) and the issues arising in the outpatient setting. This can be accomplished only through the efforts of an active and engaged multidisciplinary team.

Issues that must be taken into account in planning the care of an LVAD patient include cardiovascular disease and anticoagulation.

Coronary artery disease (CAD) in LVAD patients is usually related to the right ventricle (RV). In a right-dominant system with significant disease in the right coronary artery, a bypass graft to that artery is advisable. To the extent possible, protect all patent grafts at the time of reentry.

General guidelines for valve disease are as follows [6] :

  • Aortic stenosis - This is generally not a problem and can be left alone
  • Aortic insufficiency - This must be fixed if it is more than mild; options include bioprosthetic aortic valve replacement (AVR), oversewing the valve with a collagen-impregnated Dacron patch (eg, Hemashield; Maquet, Rastatt, Germany), and approximation of the nodes of Arantius; the authors prefer not to oversew the valve, because oversewing makes the patient completely dependent on the LVAD for left ventricular (LV) ejection
  • Prosthetic AVR - A bioprosthetic AVR is not a problem, but there are as yet no data suggesting what to do with a mechanical AVR; some surgeons recommend oversewing or replacement with a bioprosthetic AVR (especially in destination therapy [DT] patients), whereas others might consider leaving the prosthesis in place; this scenario was an exclusion criteria for patients in current trials
  • Mitral stenosis - This must be repaired to allow LV inflow; options include tissue valve replacement and, if the situation is amenable, valvuloplasty
  • Mitral regurgitation - This can be left alone unless myocardial recovery and explantation are being considered
  • Tricuspid regurgitation - Although the practice is controversial, most perform annuloplasty or replacement in the face of severe tricuspid regurgitation [7]

The authors usually administer warfarin when the patient is extubated and taking oral medications, the ultimate goal being an international normalized ratio (INR) of 1.7-2.5. If the time before initiation of warfarin is extended, the authors administer heparin.

Other circumstances can also alter surgical strategies and must therefore be taken into account in planning, including previous cardiac surgical procedures (eg, congenital repairs or ventricular restoration). [8, 9, 10]

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Equipment

No particular specialized equipment is necessary for insertion of an LVAD. Each device usually comes with its own specific tools for implantation; these tools can rarely be used on competing devices. Most centers that implant durable LVADs also have the capacity to implant either short-term or durable RV assist devices (RVADs) if necessary.

This article focuses on insertion of the Thoratec HeartMate II (see the image below), which is the dominant LVAD in the United States at present. Other devices approved by the US Food and Drug Administration (FDA) include the Jarvik 2000 (Jarvik Heart, New York, NY) and the HeartWare Ventricular Assist System [2]  (HeartWare, Framingham, MA).

HeartMate II (Thoratec, Pleasanton, CA). HeartMate II (Thoratec, Pleasanton, CA).
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Patient Preparation

Anesthesia

Standard cardiac surgery anesthesia is used with LVAD procedures. Double-lumen tubes or bronchial blockers can be used for off-pump procedures that necessitate left thoracotomy. Typical monitoring equipment routinely used includes temperature probes, pulmonary artery catheters, and cerebral oximetry.

Although most procedures are done with the use of cardiopulmonary bypass, many centers maintain low tidal volume ventilation during bypass on the grounds that this should theoretically decrease postpump pulmonary vascular resistance. Antifibrinolytic therapy is usually employed, and blood products are given as indicated. Some centers rely heavily on thrombelastography for driving replacement therapy.

Most LVAD procedures can be performed without systemic cooling, and routine measures for cardiopulmonary bypass are used. The authors frequently employ ultrafiltration and avoid excessive hemodilution. Intraoperative cell salvage should be replaced with concomitant liberal use of fresh frozen plasma (2-3:1). In patients with heparin-induced thrombocytopenia, LVAD implantation has been performed successfully, albeit with additional risk, by using alternative anticoagulants such as bivalirudin or argatroban.

After insertion of the LVAD, attention is focused on decreasing pulmonary vascular resistance and protecting RV function. Some centers routinely use nitric oxide in each case. Every effort is made to reduce transfusion requirements as well as avoid hypoxia, hypercarbia, and acidosis. Intravenous pulmonary vasodilators, including nitrates and phosphodiesterase inhibitors (milrinone), are routinely used.

Inotropic support for the RV is also routinely provided (eg, with milrinone, epinephrine, and dobutamine). The use of sildenafil in these patients is increasingly noted, both preoperatively and perioperatively. Patients with sick RVs may require mechanical support for several days (eg, with a centrifugal blood pump such as the CentriMag [Thoratec, Pleasanton, CA]).

Positioning

Most LVADs are placed with the patient in the supine position, as is standard for any cardiac surgery operation. This standard position can be used for several nonsternotomy approaches as well. For example, some surgeons have placed pumps (notably the Jarvik 2000) through a left subcostal incision, with the outflow to the supraceliac aorta. Others have used a left subcostal incision for the HeartMate II and tunneled the outflow graft to the ascending aorta through a counterincision in the right third interspace.

A left thoracotomy approach can also be used, with the outflow graft to the descending aorta. This technique has been most often applied to the off-cardiopulmonary bypass approach using the Jarvik 2000 LVAD, but in theory it could be used for several other small pumps as well. [11] In such cases, the patient should be placed in the left lateral position, with the hips turned back to give access to the left femoral vessels if needed.

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