Objective To investigate the feasibility of a long-term left ventricular assist device placed in the aortic valve annulus for terminal cardiopathy. Methods An implantable aortic valve pump （23ram outer diameter, weighing 31g） was developed. There were a central rotor and a stator in the device. The rotor was consisted of driven magnets and an impeller, the stator was consisted of a motor coil with an iron core and outflow guide vanes. The device was implanted identical to an aortic valve replacement, occupying no additional anatomic space. The blood was delivered directly from left ventricle to the aortic root by aortic valve pump like natural ventricle, neither connecting conduits nor ＂bypass＂ circuits were necessary, therefore physiologic disturbances of natural circulation was less. Results Aortic valve pump was designed to cycle between a peak flow and zero net flow to approximate systole and diastole. Bench testing indicated that a blood flow of 7L/min with 50 mmHg（1kPa = 7.5mmHg） pressure could be produced by aortic valve pump at 15 000r/min. A diastole aortic pressure of 80mmHg could be maintained by aortic valve pump at 0L/min and the same rotating speed. Conclusions This paper exhibits the possibility that an aortic valve pump with sufficient hemodynamic capacity could be made in 23mm outer diameter, 31g and it could be implantable. This achievement is a great progress to extend the applications of aortic valve pump in clinic and finally in replacing the natural donor heart for heart transplantation. Meanwhile, this is only a little step, because many important problems, such as blood compatibility and durability, require further investigation.
Objective To investigate the efficacy and safety of the Corheart 6 left ventricular assist system in patients with end-stage heart failure. Methods A retrospective study was conducted on patients with end-stage heart failure who were treated with Corheart 6 left ventricular assist system from March 2022 to June 2024 in 4 hospitals in Jiangsu Province. The efficacy of the device was evaluated by comparing changes in clinical indicators at preoperative, discharge, 3-month postoperative, and 6-month postoperative timepoints, including the New York Heart Association (NYHA) functional classification, left ventricular ejection fraction (LVEF), and left ventricular end-diastolic diameter (LVEDD). The safety of the device was assessed by analyzing the intraoperative position and orientation of the blood pump inlet cannula, as well as the incidence of adverse events. Results In this study, 39 patients were collected, including 34 males and 5 females with a mean age of (56.4±12.5) years, ranging from 20 to 75 years. There was no operative death. There was no death in postoperative 3 months with a survival rate of 100.0%. There were 3 deaths in 6 months postoperatively, with a survival rate of 92.3%. All patients had a preoperative NYHA cardiac function classification of class Ⅳ. The NYHA cardiac function class of the patients improved (P<0.05) at discharge, 3 and 6 months after surgery when compared to the preoperative period. LVEF was significantly higher at 3 months after surgery than that during the preoperative period (P<0.05). LVEDD was significantly smaller at discharge, 3 and 6 months after surgery than that during the preoperative period (P<0.05). The safety evaluation's findings demonstrated that all 39 patients' intraoperative blood pump inlet tubes were oriented correctly, the artificial blood vessel suture sites were appropriate, there were no instances of device malfunction or pump thrombosis, or instances of bleeding or hemolysis, and the rate of the remaining adverse events was low. Conclusion With a low rate of adverse events and an excellent safety profile, the Corheart 6 left ventricular assist system can efficiently enhance cardiac function in patients with end-stage heart failure. It also has considerable clinical uses.
Although heart transplantation remains to be the optimal treatment for advanced heart failure, its use has been largely limited due to shortage of available donor organs. Over the past two decades, left ventricular assist device (LVAD) has been significantly modified in size, durability and hemocompatibility. In addition to the bridge to transplantation, LVAD has become an attractive alternative to heart transplantation for end-stage heart failure as destination therapy for unsuitable candidates. Although the performance of LVAD has been improving greatly in recent years, there are still great challenges in the management of device complications and low quality of life after implantation. This review will summarize the types of LVAD, indications for implantation, postoperative management and adverse events.
ObjectiveTo explore the value of transthoracic echocardiography (TTE) to monitor and evaluate aortic insufficiency (AI) within one year after the implantation of the left ventricular assist device (LVAD).MethodsWe retrospectively collected and analyzed the TTE data of 12 patients who received LVAD implantation from 2018 to 2020 in our hospital. All patients were males, with an average age of 43.3±8.6 years. We analyzed temporal changes in the aortic annulus (AA), aortic sinus (AoS), ascending aorta (AAo), the severity of AI and the opening of aortic valve before operation and 1 month, 3 months, 6 months and 12 months after LVAD implantation.ResultsAll 12 patients survived within 1 year after LVAD implantation. One patient was bridged to heart transplantation 6 months after implantation, and two patients did not receive TTE after 3 and 6 months. Compared to pre-implantation, AoS increased at 1 month after implantation (31.58±5.09 mm vs. 33.83±4.69 mm). The inner diameters of AA, AoS and AAo increased at 3, 6 and 12 months after LVAD implantation compared to pre-implantation (P<0.05), but all were within the normal range except for one patient whose AoS slightly increased before operation. After LVAD pump speed was adjusted, the opening of aortic valve improved. The severity of AI increased at 6 and 12 months after LVAD implantation compared to pre-implantation, and increased at 12 months compared to 6 months after LVAD implantation (P<0.05).ConclusionTTE can evaluate aortic regurgitation before and after LVAD implantation and monitor the optimization and adjustment of LVAD pump function, which has a positive impact on the prognosis after LVAD implantation.
As a global disease, heart failure affects at least 26 million people, and its prevalence is still rising. Besides, the mortality rate and readmission rate remain high. Advanced heart failure is the terminal stage of various heart diseases, and often requires some treatments other than drug intervention, such as heart transplantation which is the gold standard for treatment of heart failure. However, limited by the number of donors, the number of heart transplants in the world has reached a bottleneck. There is a huge gap between the number of patients who need heart transplants and patients who get hearts for survival successfully in reality. With the exploration and development of mechanical circulation support devices for more than half a century, they have become a wonderful treatment for patients with advanced heart failure. This article will introduce the latest progress of mechanical circulatory support devices at home and abroad from the aspects of temporary and long-term devices.
In recent years, the field of cardiovascular surgery has undergone revolutionary changes and made rapid progress in various aspects, bringing more hope and possibilities for the health and well-being of patients. The constant emergence of new technologies brings new opportunities and hope, as well as constant challenges to past concepts. This article aims to provide a comprehensive overview of the latest developments in cardiovascular surgery in recent years, especially since 2023. It introduces cutting-edge knowledge and technologies in the field of cardiovascular surgery, including lifelong management of aortic valve disease, artificial valves, mitral valves, treatment options for hypertrophic obstructive cardiomyopathy, heart transplantation, left ventricular assist, coronary artery surgery, cardiac structural interventions for chronic heart failure, aortic dissection, and comprehensive surgical treatment of atrial fibrillation. It also analyzes and explores future development directions in depth, aiming to provide useful references and inspiration for cardiovascular doctors and jointly promote the continuous progress of cardiovascular surgery in China.
The implantation of a left ventricular assist device (LVAD) is an important therapeutic tool for patients with end-stage heart failure, which can either help patients transit to the heart transplantation stage or serve as destination therapy until the end of their lives. In recent years, the third generation of LVAD has evolved rapidly and several brands have been marketed both domestically and internationally. The number of LVAD implantations has been increasing and the long-term survival rate of implanted patients has improved, so this device has a broad development perspective. This article summarizes the current status, usage standards and precautions, and common complications after implantation of LVAD, as well as looks forward to the future development of LVAD, hoping to be helpful for researchers who are new to this field.
A 56-year male patient was implanted with a third generation magnetic levitation HeartCon left ventricular assist device (LVAD) for refractory heart failure through a left antero-lateral thoracotomy. Inflow cannula of the HeartCon blood pump was inserted via the left apex and outflow tract with the artificial blood vessel was sutured to the descending aorta. The operation process was smooth, the LVAD worked stably, and results of left ventricular assist was good. Implantation of HeartCon LVAD through the left antero-lateral thoracotomy is an alternative technique with less surgical complications, less trauma and satisfactory results.
The rotary left ventricular assist device (LVAD) has been an effective option for end-stage heart failure. However, while clinically using the LVAD, patients are often at significant risk for ventricular collapse, called suction, mainly due to higher LVAD speeds required for adequate cardiac output. Some proposed suction detection algorithms required the external implantation of sensors, which were not reliable in long-term use due to baseline drift and short lifespan. Therefore, this study presents a new suction detection system only using the LVAD intrinsic blood pump parameter (pump speed) without using any external sensor. Three feature indices are derived from the pump speed and considered as the inputs to four different classifiers to classify the pumping states as no suction or suction. The in-silico results using a combined human circulatory system and LVAD model show that the proposed method can detect ventricular suction effectively, demonstrating that it has high classification accuracy, stability, and robustness. The proposed suction detection system could be an important part in the LVAD for detecting and avoiding suction, while at the same time making the LVAD meet the cardiac output demand for the patients. It could also provide theoretical basis and technology support for designing and optimizing the control system of the LVAD.
Right ventricular (RV) failure has become a deadly complication of left ventricular assist device (LVAD) implantation, for which desynchrony in bi-ventricular pulse resulting from a LVAD is among the important factor. This paper investigated how different control modes affect the synchronization of pulse between LV (left ventricular) and RV by numerical method. The numerical results showed that the systolic duration between LV and RV did not significantly differ at baseline (LVAD off and cannula clamped) (48.52% vs. 51.77%, respectively). The systolic period was significantly shorter than the RV systolic period in the continuous-flow mode (LV vs. RV: 24.38% vs. 49.16%) and the LV systolic period at baseline. The LV systolic duration was significantly shorter than the RV systolic duration in the pulse mode (LV vs. RV: 28.38% vs. 50.41%), but longer than the LV systolic duration in the continuous-flow mode. There was no significant difference between the LV and RV systolic periods in the counter-pulse mode (LV vs. RV: 43.13% vs. 49.23%). However, the LV systolic periods was shorter than the no-pump mode and much longer than the continuous-flow mode. Compared with continuous-flow and pulse mode, the reduction in rotational speed (RS) brought out by counter-pulse mode significantly corrected the duration of LV systolic phase. The shortened duration of systolic phase in the continuous-flow mode was corrected as re-synchronization in the counter-pulse mode between LV and RV. Hence, we postulated that the beneficial effects on RV function were due to re-synchronizing of RV and LV contraction. In conclusion, decreased RS delivered during the systolic phase using the counter-pulse mode holds promise for the clinical correction of desynchrony in bi-ventricular pulse resulting from a LVAD and confers a benefit on RV function.