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The Journal of Surgical Research Dec 2015We tested the short-term effects of completely nonpulsatile versus pulsatile circulation after ventricular excision and replacement with total implantable pumps in an... (Comparative Study)
Comparative Study
BACKGROUND
We tested the short-term effects of completely nonpulsatile versus pulsatile circulation after ventricular excision and replacement with total implantable pumps in an animal model on peripheral vascular permeability.
METHODS
Ten calves underwent cardiac replacement with two HeartMate III continuous-flow rotary pumps. In five calves, the pump speed was rapidly modulated to impart a low-frequency pulse pressure in the physiologic range (10-25 mm Hg) at a rate of 40 pulses per minute (PP). The remaining five calves were supported with a pulseless systemic circulation and no modulation of pump speed (NP). Skeletal muscle biopsies were obtained before cardiac replacement (baseline) and on postoperative days (PODs) 1, 7, and 14. Skeletal muscle-tissue water content was measured, and morphologic alterations of skeletal muscle were assessed. VE-cadherin, phospho-VE-cadherin, and CD31 were analyzed by immunohistochemistry.
RESULTS
There were no significant changes in tissue water content and skeletal muscle morphology within group or between groups at baseline, PODs 1, 7, and 14, respectively. There were no significant alterations in the expression and/or distribution of VE-cadherin, phospho-VE-cadherin, and CD31 in skeletal muscle vasculature at baseline, PODs 1, 7, and 14 within each group or between the two groups, respectively. Although continuous-flow total artificial heart (CFTAH) with or without a pulse pressure caused slight increase in tissue water content and histologic damage scores at PODs 7 and 14, it failed to reach statistical significance.
CONCLUSIONS
There was no significant adherens-junction protein degradation and phosphorylation in calf skeletal muscle microvasculature after CFTAH implantation, suggesting that short term of CFTAH with or without pulse pressure did not cause peripheral endothelial injury and did not increase the peripheral microvascular permeability.
Topics: Adherens Junctions; Animals; Antigens, CD; Cadherins; Capillary Permeability; Cattle; Edema; Endothelium, Vascular; Female; Heart, Artificial; Hemorheology; Male; Microvessels; Muscle, Skeletal
PubMed: 26188957
DOI: 10.1016/j.jss.2015.06.035 -
European Journal of Cardio-thoracic... Dec 2014
Topics: Aged; Female; Heart Failure; Heart, Artificial; History, 20th Century; History, 21st Century; Humans; Male; Middle Aged; Prosthesis Design
PubMed: 25228743
DOI: 10.1093/ejcts/ezu333 -
ASAIO Journal (American Society For... Mar 2020The need for biventricular support poses significant challenges for patients who require a mechanical bridge to transplantation. Recent improvements in ventricular...
The need for biventricular support poses significant challenges for patients who require a mechanical bridge to transplantation. Recent improvements in ventricular assist device (VAD) technology has made possible the use of two centrifugal flow VADs as a total artificial heart (TAH) replacement. The HeartMate 3 (HM3; [Full MagLev, Abbott Laboratories, Chicago, Illinois]) was recently approved as a destination therapy; this VAD has a number of unique advantages that allow for its off-label use for biventricular support. Here, we describe the use of two HM3s as a TAH in a patient as a bridge to transplant.
Topics: Adult; Heart Failure; Heart Transplantation; Heart, Artificial; Heart-Assist Devices; Humans; Male
PubMed: 31045916
DOI: 10.1097/MAT.0000000000001011 -
Annual Review of Biomedical Engineering Jun 2022The treatment of end-stage heart failure has evolved substantially with advances in medical treatment, cardiac transplantation, and mechanical circulatory support (MCS)... (Review)
Review
The treatment of end-stage heart failure has evolved substantially with advances in medical treatment, cardiac transplantation, and mechanical circulatory support (MCS) devices such as left ventricular assist devices and total artificial hearts. However, current MCS devices are inherently blood contacting and can lead to potential complications including pump thrombosis, hemorrhage, stroke, and hemolysis. Attempts to address these issues and avoid blood contact led to the concept of compressing the failing heart from the epicardial surface and the design of direct cardiac compression (DCC) devices. We review the fundamental concepts related to DCC, present the foundational devices and recent devices in the research and commercialization stages, and discuss the milestones required for clinical translation and adoption of this technology.
Topics: Biomechanical Phenomena; Heart; Heart Failure; Heart, Artificial; Heart-Assist Devices; Humans
PubMed: 35395165
DOI: 10.1146/annurev-bioeng-110220-025309 -
Medical Science Monitor Basic Research Oct 2014End-stage heart failure is a major health problem, but implementation of guidelines and optimizing medical therapy for this devastating disease should decrease... (Review)
Review
End-stage heart failure is a major health problem, but implementation of guidelines and optimizing medical therapy for this devastating disease should decrease mortality. If optimal conservative therapy is no longer sufficient, a mechanical support system may be required as final destination therapy or as bridge-to-transplant. Since the first heart transplantation in 1967, this therapy has become the criterion standard for end-stage heart failure, but is limited due to organ shortage. Tissue engineering could help overcome this limitation and provide regeneration, remodeling, and growth potential. This so-called bio-artificial heart would be available, created by a decellularized extracellular matrix and seeded with in vitro proliferated autologous cardiovascular cells. Results of the first experimental studies have been promising, but numerous challenges must be met before this procedure will be available.
Topics: Animals; Heart Failure; Heart Transplantation; Heart, Artificial; Humans; Tissue Engineering
PubMed: 25321347
DOI: 10.12659/MSMBR.892287 -
Artificial Organs Aug 2022Mechanical circulatory support (MCS) devices, such as ventricular assist devices (VADs) and total artificial hearts (TAHs), have become a vital therapeutic option in the... (Review)
Review
BACKGROUND
Mechanical circulatory support (MCS) devices, such as ventricular assist devices (VADs) and total artificial hearts (TAHs), have become a vital therapeutic option in the treatment of end-stage heart failure for adult patients. Such therapeutic options continue to be limited for pediatric patients. Clinicians initially adapted or scaled existing adult devices for pediatric patients; however, these adult devices are not designed to support the anatomical structure and varying flow capacities required for this population and are generally operated "off-design," which risks complications such as hemolysis and thrombosis. Devices designed specifically for the pediatric population which seek to address these shortcomings are now emerging and gaining FDA approval.
METHODS
To analyze the competitive landscape of pediatric MCS devices, we conducted a systematic literature review. Approximately 27 devices were studied in detail: 8 were established or previously approved designs, and 19 were under development (11 VADs, 5 Fontan assist devices, and 3 TAHs).
RESULTS
Despite significant progress, there is still no pediatric pump technology that satisfies the unique and distinct design constraints and requirements to support pediatric patients, including the wide range of patient sizes, increased cardiovascular demand with growth, and anatomic and physiologic heterogeneity of congenital heart disease.
CONCLUSIONS
Forward-thinking design solutions are required to overcome these challenges and to ensure the translation of new therapeutic MCS devices for pediatric patients.
Topics: Child; Extracorporeal Membrane Oxygenation; Heart Failure; Heart, Artificial; Heart-Assist Devices; Humans; Technology
PubMed: 35357020
DOI: 10.1111/aor.14242 -
Journal of Cardiac Surgery Dec 2022There continues to be an unmet therapeutic need for an alternative treatment strategy for respiratory distress and lung disease. We are developing a portable...
There continues to be an unmet therapeutic need for an alternative treatment strategy for respiratory distress and lung disease. We are developing a portable cardiopulmonary support system that integrates an implantable oxygenator with a hybrid, dual-support, continuous-flow total artificial heart (TAH). The TAH has a centrifugal flow pump that is rotating about an axial flow pump. By attaching the hollow fiber bundle of the oxygenator to the base of the TAH, we establish a new cardiopulmonary support technology that permits a patient to be ambulatory during usage. In this study, we investigated the design and improvement of the blood flow pathway from the inflow-to-outflow of four oxygenators using a mathematical model and computational fluid dynamics (CFD). Pressure loss and gas transport through diffusion were examined to assess oxygenator design. The oxygenator designs led to a resistance-driven pressure loss range of less than 35 mmHg for flow rates of 1-7 L/min. All of the designs met requirements. The configuration having an outside-to-inside blood flow direction was found to have higher oxygen transport. Based on this advantageous flow direction, two designs (Model 1 and 3) were then integrated with the axial-flow impeller of the TAH for simulation. Flow rates of 1-7 L/min and speeds of 10,000-16,000 RPM were analyzed. Blood damage studies were performed, and Model 1 demonstrated the lowest potential for hemolysis. Future work will focus on developing and testing a physical prototype for integration into the new cardiopulmonary assist system.
Topics: Humans; Equipment Design; Oxygenators; Heart, Artificial; Hemodynamics
PubMed: 36403254
DOI: 10.1111/jocs.17210 -
The Kurume Medical Journal Sep 2023Mechanical circulatory support has been an indispensable treatment for severe heart failure. While the development of a total artificial heart has failed, left...
Mechanical circulatory support has been an indispensable treatment for severe heart failure. While the development of a total artificial heart has failed, left ventricular assist devices (LVAD) have evolved from extracorporeal to implantable types. The first generation implantable LVAD (pulsatile device) was used as a bridge to transplantation, and demonstrated improvement in survival rate and activity of daily living. The evolution from the first-generation (pulsatile device) to the second-generation (continuous flow device: axial flow pump and centrifugal pump) has resulted in many clinical benefits by reducing mechanical failures and minimizing device size. Furthermore, third-generation devices, which use a moving impeller suspended by magnetic and/or hydrodynamic forces, have improved overall device reliability and durability. Unfortunately, there are still many device-related complications, and further device development and improvement of patient management methods are required. However, we expect to see further development of implantable VADs, including for destination therapy, in future.
Topics: Humans; Heart-Assist Devices; Heart Failure; Reproducibility of Results
PubMed: 37316290
DOI: 10.2739/kurumemedj.MS6834007 -
The Journal of Thoracic and... Aug 2020
Topics: Clinical Competence; Extracorporeal Membrane Oxygenation; Health Care Rationing; Health Services Needs and Demand; Heart-Assist Devices; Humans; Pandemics; Respiration, Artificial; Surge Capacity; Surgeons; Thoracic Surgical Procedures; Ventilators, Mechanical
PubMed: 32689702
DOI: 10.1016/j.jtcvs.2020.03.117 -
The Annals of Thoracic Surgery Jan 2013With implantable cardiac assist devices increasingly proving their effectiveness as therapeutic options for end-stage heart failure, it is important for clinicians to... (Review)
Review
With implantable cardiac assist devices increasingly proving their effectiveness as therapeutic options for end-stage heart failure, it is important for clinicians to understand the unique physiology of device-assisted circulation. Preload sensitivity as it relates to cardiac assist devices is derived from the Frank-Starling relationship between human ventricular filling pressures and ventricular stroke volume. In this review, we stratify the preload sensitivity of 17 implantable cardiac assist devices relative to the native heart and discuss the effect of preload sensitivity on left ventricular volume unloading, levels of cardiac support, and the future development of continuous-flow total artificial heart technology.
Topics: Equipment Design; Heart Failure; Heart-Assist Devices; Humans; Ventricular Pressure
PubMed: 23272869
DOI: 10.1016/j.athoracsur.2012.07.077