Preclinical Assessment of a Rapid Anastomotic Device for HeartMate 3 Apical Cuff Implantation

• Published in: The Journal of heart and lung transplantation Vol. 41; no. 4; pp. S102 - S103
• Main Authors: Mitchell, M.B., Banas, C.E., Morgan, J.H., Sims, D.D.
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01.04.2022
• ISSN: 1053-2498; 1557-3117
• DOI: 10.1016/j.healun.2022.01.238

The HeartMate3 (HM3) LVAD requires an apical cuff (AC) to left ventricle (LV) anastomosis. We developed an AC attachment device for the standard HM3 AC with 12 anchors and 4 compression plates. A Gen1 delivery tool requires a hand-held driver and sequential anchor delivery. A Gen2 delivery tool with a targeting system and improved anchors has a planetary gear mechanism that drives all anchors simultaneously. The study purpose was to assess functionality and hemostasis of HM3 AC anastomosis. Standard HM3 ACs were implanted without cardiopulmonary bypass (CPB) in 8 calves (110 to 130 kg): left thoracotomy (n=2), median sternotomy (n=6). Implant time was from epicardial contact to complete anchor deployment. Blood pressure (BP) was measured by arterial line. After anchor deployment and AC attachment heparin was administered to ACT over 400 seconds. Fibrillation (n=2), rapid pacing (n=1) and vena cava inflow occlusion (n=5) were used for LV coring and custom AC plug insertion with resuscitation to baseline BP. Functionality and hemostasis were qualitatively assessed. Supraphysiologic testing (norepinephrine, 0.15 mcg/kg/min) was assessed in 4 cases (Gen1, n=3; Gen2, n=1). Implants were simple. Gen1 (n=6) implant time range was 63 to 94 seconds. Gen2 (n=2) times were 26 and 32 seconds. Prior to anticoagulation hemostasis was excellent. Five cases were assessed for post-plug hemostasis (2 fibrillated and 1 paced could not be resuscitated). After resuscitation there was minimal to no bleeding in 3 cases (2 Gen 1, 1 Gen 2). In 2 cases (1 Gen1, 1 Gen2) sutures were required at a single anchor site: 1 Gen1 had localized bleeding due to a single anchor failure (cap separation), 1 Gen2 had bleeding at a coronary artery perforation. Excellent hemostasis was maintained at supraphysiologic pressures (n=4, systolic BP range 211-248 mmHg). Rapid HM3 apical cuff attachment is feasible. Hemostasis was excellent even at significant supraphysiologic blood pressure. Advantages are: 1) No HM3 AC manufacturing changes are required, 2) Implant time is greatly decreased, 3) Implant is easy without CPB, 4) Implant site targeting is precise, 5) The area of impacted myocardium is limited to the area under the AC sewing skirt, and 6) Low device profile permits use with mini-thoracotomy access. Suturing buttressing is feasible and may be necessary in case of coronary artery perforation.