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Median Sternotomy or Right Thoracotomy Techniques for Total Artificial Heart Implantation in Calves
Karimov, Jamshid H; Moazami, Nader; Sunagawa, Gengo; Kobayashi, Mariko; Byram, Nicole; Sale, Shiva; Such, Kimberly A; Horvath, David J; Golding, Leonard A R; Fukamachi, Kiyotaka
The choice of optimal operative access technique for mechanical circulatory support device implantation ensures successful postoperative outcomes. In this study, we retrospectively evaluated the median sternotomy and lateral thoracotomy incisions for placement of the Cleveland Clinic continuous-flow total artificial heart (CFTAH) in a bovine model. The CFTAH was implanted in 17 calves (Jersey calves; weight range, 77.0-93.9 kg) through a median sternotomy (n = 9) or right thoracotomy (n = 8) for elective chronic implantation periods of 14, 30, or 90 days. Similar preoperative preparation, surgical techniques, and postoperative care were employed. Implantation of the CFTAH was successfully performed in all cases. Both methods provided excellent surgical field visualization. After device connection, however, the median sternotomy approach provided better visualization of the anastomoses and surgical lines for hemostasis confirmation and repair due to easier device displacement, which is severely limited following right thoracotomy. All four animals sacrificed after completion of the planned durations (up to 90 days) were operated through full median sternotomy. Our data demonstrate that both approaches provide excellent initial field visualization. Full median sternotomy provides larger viewing angles at the anastomotic suture line after device connection to inflow and outflow ports.
PMID: 26684685
ISSN: 1525-1594
CID: 2465292
Outcomes for Patients With Diabetes After Continuous-Flow Left Ventricular Assist Device Implantation
Vest, Amanda R; Mistak, Stanley M; Hachamovitch, Rory; Mountis, Maria M; Moazami, Nader; Young, James B
BACKGROUND: Diabetes mellitus (DM) is a risk factor for mortality among patients with heart failure as well as for patients who undergo cardiothoracic surgery. However it is unknown whether DM is associated with increased mortality or major complications during continuous-flow left ventricular assist device (CF-LVAD) support. METHODS AND RESULTS: We retrospectively reviewed 300 consecutive adults who received CF-LVADs at a single center in the years 2006-2013; 129 patients had DM before LVAD, as defined by American Diabetes Association criteria (HbA1c >/=6.5% and/or taking DM medications). Compared with the non-DM group, DM patients were older, with a higher pre-LVAD body mass index, more ischemic heart failure etiology, and higher pre-LVAD creatinine. Ninety-three patients died on LVAD support, 43 with DM and 50 without DM (P = .4526). After control for 9 covariates in a Cox proportional hazards model, DM was unassociated with all-cause mortality (hazard ratio 0.883, 95% confidence interval 0.571-1.366; P = .5768). Diabetes was also unassociated with the adverse event end points of stroke/transient ischemic attack, intracerebral hemorrhage, pump thrombosis, and device-related infections. CONCLUSIONS: Diabetes is common in LVAD recipients (43% of the present cohort) but does not increase mortality or rates of major adverse events during CF-LVAD support.
PMID: 26924520
ISSN: 1532-8414
CID: 2465282
Limitations to Chronic Right Ventricular Assist Device Support
Karimov, Jamshid H; Sunagawa, Gengo; Horvath, David; Fukamachi, Kiyotaka; Starling, Randall C; Moazami, Nader
Failure of the right ventricle represents a significant clinical problem and may have different causes, with rates varying between 5% and 50% in patients supported by a left ventricular assist device (LVAD). However, treatment options and device development for right ventricular failure (RVF) have significantly lagged behind those for LVADs. Newer technologies designed or adapted for RV support are needed to provide adequate long-term circulatory support. In this review, we discuss (1) the significance of RVF and its physiologic implications, (2) device constraints affecting treatment options for RVF, and (3) implantable VADs potentially available for RV support.
PMID: 27106620
ISSN: 1552-6259
CID: 2465312
The Contribution to Hemodynamics Even at Very Low Pump Speeds in the HVAD
Sunagawa, Gengo; Byram, Nicole; Karimov, Jamshid H; Horvath, David J; Moazami, Nader; Starling, Randall C; Fukamachi, Kiyotaka
BACKGROUND: We recently reported using bench testing that the Thoratec HeartMate II at 6,000 rpm contributed to hemodynamics when the heart had not recovered well, making weaning assessment questionable. In this bench study, we characterized hemodynamics and pump flow of the HeartWare HVAD at 1,800 rpm, the lowest speed commonly used to assess clinical recovery. METHODS: The HVAD was operated in a mock loop at 1,800, 2,400, and 3,000 rpm. We acquired pressure-flow curves in each steady state. In pulsatile mode with the pneumatic ventricle (heart simulator) activated, pump flow, total flow, and aortic pressure (AoP) data were obtained under conditions simulating normal heart function or heart failure. RESULTS: A large regurgitant flow during diastole was confirmed during normal heart function at 1,800 rpm support; however, the net flow was zero, and there was no difference in mean AoP between 1,800 rpm support and no HVAD support. In contrast, in the heart failure condition, HVAD flow at 1,800 rpm significantly contributed to mean AoP and total flow, because there was less regurgitant flow. CONCLUSIONS: Similar to the results for the HeartMate II at 6,000 rpm, we found that the net pump flow generated by the HeartWare HVAD at 1,800 rpm depends on the degree of residual left ventricular (LV) function. In the setting of improved LV function, at 1,800 rpm we noted a large regurgitant flow. Although this "marker" can serve as a useful indicator for recovery, assessing recovery at this speed is flawed unless measures are taken to prevent regurgitant flow.
PMID: 26912300
ISSN: 1552-6259
CID: 2465332
Mechanical circulatory support in pediatrics
Steffen, Robert J; Miletic, Kyle G; Schraufnagel, Dean P; Vargo, Patrick R; Fukamachi, Kiyotaka; Stewart, Robert D; Moazami, Nader
End-stage heart failure affects thousands of children yearly and mechanical circulatory support is used at many points in their care. Extracorporeal membrane oxygenation supports both the failing heart and lungs, which has led to its use as an adjunct to cardiopulmonary resuscitation as well as in post-operative cardiogenic shock. Continuous-flow ventricular assist devices (VAD) have replaced pulsatile-flow devices in adults and early studies have shown promising results in children. The Berlin paracorporeal pulsatile VAD recently gained U.S. Food and Drug Administration approval and remains the only VAD approved in pediatrics. Failing univentricular hearts and other congenitally corrected lesions are new areas for mechanical support. Finding novel uses, improving durability, and minimizing complications are areas of growth in pediatric mechanical circulatory support.
PMID: 26950799
ISSN: 1745-2422
CID: 2465342
Optimal Timing of Heart Transplantation After HeartMate II Left Ventricular Assist Device Implantation [Meeting Abstract]
Steffen, RJ; Blackstone, EH; Smedira, NG; Soltesz, EG; Hoercher, KJ; Thuita, L; Starling, RC; Mountis, M; Moazami, N
ISI:000374718100563
ISSN: 1557-3117
CID: 2467382
Time-Varying Mortality Risk Score for Candidates Awaiting Cardiac Transplantation [Meeting Abstract]
Cruz, VB; Steffen, R; Koprivanac, M; Starling, RC; Taylor, DO; Hoercher, K; Rajeswaran, J; Smedira, N; Soltesz, E; Blackstone, EH; Moazami, N
ISI:000374718100585
ISSN: 1557-3117
CID: 2467392
Generating Pulsatility by Pump Speed Modulation with Continuous-Flow Total Artificial Heart in Awake Calves [Meeting Abstract]
Fukamachi, K; Karimov, JH; Sunagawa, G; Horvath, DJ; Byram, N; Kuban, BD; Dessoffy, R; Sale, S; Moazami, N
ISI:000374718100327
ISSN: 1557-3117
CID: 2467372
Advanced Ventricular Assist Device with Pulse Augmentation and Automatic Regurgitant Flow Shutoff [Meeting Abstract]
Fukamachi, K; Horvath, DJ; Byram, N; Sunagawa, G; Karimov, JH; Kuban, BD; Dessoffy, R; Moazami, N
ISI:000374718101266
ISSN: 1557-3117
CID: 2467412
Evaluation of Changes in Flow Associated with HeartMate II Inflow Cannula Angle Change [Meeting Abstract]
Karimov, JH; Tong, M; Byram, N; Sunagawa, G; Dessoffy, R; Moazami, N; Starling, R; Fukamachi, K
ISI:000374718101255
ISSN: 1557-3117
CID: 2467402