Left ventricular assist device driveline infections

This article reviews some important aspects of driveline infection in patients under left ventricular assist device (LVAD) support, including epidemiology, causes, diagnosis, and treatment options, both medical and surgical. Focus is placed on prevention along every aspect of the process of LVAD therapy, as the authors believe this is the most efficient measure to fight driveline infections. Once driveline infection is present, early recognition and adequate treatment, including surgical measures, play a central role management, and are key to achieving the goals of LVAD support.     

Minimally invasive is the future of left ventricular assist device implantation

There have been many factors that have allowed for progressive improvement in outcomes and lower complication rates. These include the improvement in left ventricular assist device (LVAD) technologies, combined with better understanding of patient management, all these. Nowadays the numbers of LVAD implantations exceed the number of annual heart transplants worldwide. Minimally invasive procedures are shown to improve the surgical outcome in both LVAD insertion and replacement. These minimally invasive techniques can be grouped grossly into shifting from on-pump to off-pump implantation, alternative access for implantation other than sternotomy, and a combination of both, which should be the ultimate aim of minimally invasive LVAD implantation. Here we describe the alternative techniques and configurations of minimally invasive and sites of implantation.     

Right ventricular failure after left ventricular assist device implantation: a review of the literature

Right ventricular failure (RVF) following left ventricular assist device (LVAD) implantation remains a major complication which may significantly impair patient outcome. The genesis of RVF is, however, multifactorial, and the mechanisms underlying such a condition have not been fully elucidated, making its prevention challenging and the course not always predictable. Although preoperative risks factors can be associated with RV impairment, the physiologic changes after the LV support, can still hamper the function of the RV. Current medical treatment options are limited and sometimes, patients with a severe post-LVAD RVF may be unresponsive to pharmacological therapy and require more aggressive treatment, such as temporary RV support. We retrieved 11 publications which we assessed and divided in groups based on the RV support [extracorporeal membrane oxygenation (ECMO), right ventricular assist device (RVAD), TandemHeart with ProtekDuo cannula]. The current review comprehensively summarizes the main studies of the literature with particular attention to the RV physiology and its changes after the LVAD implantation, the predictors and prognostic score as well as the different modalities of temporary mechanical cardio-circulatory support, and its effects on patient prognosis for RVF in such a setting. In addition, it provides a decision making of the pre-, intra and post-operative management in high- and moderate- risk patients.     

Remote hemodynamic monitoring for ambulatory left ventricular assist device patients

Left ventricular assist devices (LVADs) have been shown to markedly improve survival and quality of life in patients with end-stage heart failure. However, despite ongoing improvements in survival and quality of life, significant challenges still exist in the management of these patients, including a high rate of recurrent heart failure and rehospitalizations. Similar challenges exist in the non-LVAD heart failure population as well, and recent efforts to utilize remote hemodynamic monitoring techniques to improve outcomes have shown promise. No data currently exist demonstrating extension of this benefit into the LVAD population, although a theoretical benefit can be extrapolated. Herein we review current remote hemodynamic methods and potential applications towards LVAD patients.     

The future of left ventricular assist devices

The widespread acceptance of left ventricular assist device (LVAD) implantation in the treatment of heart failure has revolutionized the way end stage heart failure is treated. Advances in LVAD technology combined with a better understanding of patient selection has led to unparalleled survival as well as a reduction in the adverse event profile of these pumps. As our understanding of heart failure continues to grow, there is little doubt that LVADs will continue to play a pivotal role as a therapeutic option for those suffering from heart failure.     

Avoiding technical pitfalls in left ventricular assist device placement

Left ventricular assist device (LVAD) placement is a serious surgical procedure. At our center, we accumulated a very large experience with the Novacor LVAD from the very first clinical trial, as well as from more recent experiences with the Jarvik 2000 and the HeartMate II. This article discusses technical issues that are common to all durable LVAD devices, with special emphasis on strategy and technical considerations aimed at avoiding surgical pitfalls.     

左心辅助装置对缺血性心衰犬血浆脑钠素水平的影响

目的　研究急性缺血性左心功能不全时左心辅助装置 (LVAD)对左心功能的影响和血浆脑钠素 (BNP)变化情况。方法　将 10只健康成年犬随机分为对照组 (A)和辅助组 (B) ,两组皆以主动脉 -左心房旁路方式植入左心辅助装置 ,在阻断实验犬左冠脉前降支主干 4 0min后开放血流 ,其中仅对B组实验犬进行左心辅助。监测 6h内两组实验犬平均动脉压 (MAP)、心输出量 (CO)、左室收缩末期压(LVESP)、肺毛细血管楔压 (PCWP)、左室压力一阶导数(LVdp/dt)等血流动力学指标及血浆BNP水平变化情况。结果　开放左前降支 6h后 ,对照组实验犬 :MAP(72 2± 8 11)mmHg,LVESP (88 8± 5 4 )mmHg ,LVdp/dt 1839± 176 ,PCWP(9 6 8± 1 4 1)mmHg ,CO(0 98± 0 13)L/min ,BNP(15 3± 7 13)pg/mL。经过 6h左心辅助循环 ,辅助组实验犬各项血流动力学指标明显改善 ,MAP (87± 6 0 4 )mmHg ,LVESP(12 1 6± 2 88)mmHg ,LVdp/dt 2 5 90± 12 6 ,PCWP (6 5 6±0 5 1)mmHg ,CO(1 5 2± 0 16 )L/min ,BNP(6 2 5± 3 4 7)pg/mL基本降至正常水平。血浆BNP水平基本不受血流动力学变化影响。结论　左心辅助装置对于缺血性心衰具有良好的治疗作用 ,促进了心肌功能恢复 ,明显降低血浆BNP水平 ,血浆BNP水平可以较好地反映心肌功能状态。     

Effects of left ventricular assist device on pulmonary functions and pulmonary hemodynamics: A meta-analysis

BACKGROUNDGiven current evidence, the effect of left ventricular assist device (LVAD) implantation on pulmonary function tests remains controversial.AIMTo better understand the factors contributing to the changes seen on pulmonary function testing and the correlation with pulmonary hemodynamics after LVAD implantation.METHODSElectronic databases were queried to identify relevant articles. The summary effect size was estimated as a difference of overall means and standard deviation on a random-effects model.RESULTSA total of four studies comprising 219 patients were included. The overall mean forced expiratory volume in one second (FEV1), forced vital capacity (FVC) and diffusion lung capacity of carbon monoxide (DLCO) after LVAD implantation were significantly lower by 0.23 L (95%CI: 0.11-0.34, P = 00002), 0.18 L (95%CI: 0.03-0.34, P = 0.02), and 3.16 mmol/min (95%CI: 2.17-4.14, P < 0.00001), respectively. The net post-LVAD mean value of the cardiac index was significantly higher by 0.49 L/min/m² (95%CI: 0.31-0.66, P < 0.00001) compared to pre-LVAD value. The pulmonary capillary wedge pressure and pulmonary vascular resistance were significantly reduced after LVAD implantation by 8.56 mmHg (95%CI: 3.78-13.35, P = 0.0004), and 0.83 Woods U (95%CI: 0.11-1.55, P = 0.02), respectively. There was no significant difference observed in the right atrial pressure after LVAD implantation (0.61 mmHg, 95%CI: -2.00 to 3.32, P = 0.65). Overall findings appear to be driven by studies using HeartMateII devices.CONCLUSIONLVAD implantation might be associated with a significant reduction of the spirometric measures, including FEV1, FVC, and DLCO, and an overall improvement of pulmonary hemodynamics.     

Subacute gastric perforation caused by a left ventricular assist device

This case report describes a rare complication of a left ventricular assist device (LVAD). A patient with ischemic cardiomyopathy had an LVAD placed due to intractable congestive heart failure following a large anterior myocardial infarction. The patient developed chronic bacteremia and multiple septic episodes. A gastric endoscopy revealed perforation of the anterior wall of the stomach by the LVAD. Gastric acid related erosions were present on the metallic surface suggesting prolonged exposure. This is the second case report of this rare complication and the first case report of a subacute course.     

Multidisciplinary management of pleural infection after ventricular assist device implantation

BackgroundPostsurgical pleural infection is a life-threatening complication after implantation of artificial devices such as ventricular assist devices (VADs). The treatment can be challenging and the evidence in the literature is very limited. Here we report our multidisciplinary approach of the management of pleural infection after VAD implantation.MethodsBetween March 2014 and December 2019, 33 patients developed postoperative pleural infection after VAD implantation and underwent thoracic surgical intervention at our institution. All patients were prospectively enrolled in this analysis. Data were retrospectively analyzed. Primary outcome was the 90-day mortality rate. Length of ICU stay related to pleural infection, chest tube duration, re-thoracotomy rate and length of ventilatory support represented secondary outcomes.ResultsThe 90-day mortality rate was 6% (2 patients). The mean ICU stay related to the pleural infection was 6 days (2–24 days). Video-assisted thoracoscopic surgery (VATS) was performed in all patients. Conversion to thoracotomy was necessary in 12 cases. Decortication and parietal pleurectomy in addition to hematoma and empyema removal was performed in all patients. Due to diffuse bleeding, packing of the thoracic cavity with temporary thoracic closure was necessary in 10 patients. Depacking was performed after a mean of 3 days (3–7 days). Recurrent empyema or bleeding after definitive chest closure was not observed. Lung resection was performed in 3 patients.ConclusionsThoracic surgical management of pleural infection in patients after VAD implantation is challenging and complicated due to the inevitable anticoagulative therapy. A perioperative multidisciplinary management which includes the early involvement of thoracic surgical expertise helps to improve survival in this very complex patient cohort.     

Minimally invasive implantation of left ventricular assist device HeartWare HVAD

IntroductionLong-term left ventricular assist devices are nowadays part of standard therapy for patients in terminal phase of heart failure. Lower invasiveness of implantation might have the potential to enhance results of these high risk patients. The aim of this study is to introduce our minimally invasive approach to the implantation of left ventricular assist device of the latest generation HeartWare ventricle assist device (HVAD) and our initial experience with this method.MethodsIn our department we implanted HVAD between November 2013 and November 2014 in 8 patients as a bridge to heart transplantation. All patients were male with average age 59.5 ± 6.4 years. Basic diseases were dilated cardiomyopathy in 6 patients (75%), ischemic cardiomyopathy in 2 patients (25%). The mean value of left ventricular ejection fraction was 10 ± 3.6%, right ventricular ejection fraction was 35 ± 5.6%. Access to the left ventricular apex was reached by left-sided thoracotomy of approximately 8 cm. To access the ascending aorta we used upper J ministernotomy.ResultsMinimally invasive implantation was successfully done in all patients. In one patient closure of foramen ovale was simultaneously performed. Most patients (75%) were extubated on the first postoperative day. In one case, a failure of the right ventricle occurred with the need for temporary right-sided circulatory support device Centrimag. No patient died, four patients have successfully undergone heart transplantation, other are followed on an outpatient basis.ConclusionMinimally invasive implantation of left ventricular assist device HeartWare HVAD is safely feasible. After a very good initial experience with this technique it has become the method of choice in our department.     

Emerging roles of left ventricular assist device therapy as bridge to transplant in an Asian city with scarce heart transplant donor

BackgroundLeft ventricular assist device (LVAD) has been increasingly used in patients with advanced heart failure. This study aimed to assess the impact of implementation of LVAD therapy on heart transplantation (HTx) service in Hong Kong (HK).MethodsLVAD program was started in 2010 in HK and patients who had been put on HTx waiting list since the start of HTx program in HK from 1992 to 2020 were included for analysis. Survival on HTx waiting list between pre-LVAD era 1992–2009 and post-LVAD era 2010–2020 were analyzed by Kaplan-Meier method and compared by log-rank test. Multivariate analysis by time-dependent Cox-proportional hazard model was used to identify independent predictors of HTx waiting list mortality.ResultsA total of 478 heart transplant listing episodes involving 457 patients were included for analysis. There were 232 heart transplantations (HTxs), including one re-transplantation, during the study period. There were 110 patients who received LVAD as bridge to transplantation (BTT) and 30 of them had undergone subsequent HTx. The 1-, 2- and 3-year survival on waiting list were 82.3%, 61.7% and 43.0% respectively in the pre-LVAD era (n=178), while the 1-, 2- and 3-year survival were significantly improved at 85.7%, 81.8% and 78% respectively in the post-LVAD era (n=300), (P=0.003). Time-dependent multivariate analysis revealed that LVAD support was independently associated with significant reduction of waiting list mortality [odds ratio (OR): 0.21; 95% confidence interval (CI): 0.10–0.44, P<0.001]. There was no significant difference when comparing survival after LVAD as BTT and survival after HTx up to 8 years (76.1% vs. 72% at 8 years respectively, P=0.732).ConclusionsWaiting list survival improved in the post-LVAD era driven by the implementation of LVAD service. Long-term survival for LVAD recipients as BTT were comparable to heart transplant recipients in HK.     

Echocardiographic assessment for ventricular assist device placement

While many factors depend on successful implantation and outcome of left ventricular assist devices (LVAD), echocardiography remains an integral part and is vital to the success of this process. Transesophageal echocardiography (TEE) allows interrogation of all the cardiac structures and great vessels. The pre-implantation TEE exam establishes a baseline and may identify potential problems that need palliation. Among these, most significant are aortic insufficiency (AI), intracardiac thrombi, poor right ventricular (RV) function, and intracardiac shunts. The post-implantation exam allows for adequate de-airing of the heart and successful LVAD initiation. The position and flow profiles of the inflow and outflow cannulas of the LVAD may be assessed. Finally, it assists in the astute management and vigilant identification and correction of a number of complications in the immediate post-implantation period. TEE will continue to remain vital to the successful outcomes LVAD patients.     

Evolvement of left ventricular assist device: the implications on heart failure management

Heart failure (HF) is a potentially fatal disease that affects increasing number of people worldwide. Although heart transplant is the “gold standard” therapy for HF, due to the limited availability of organs, many patients died when waiting for the transplant. Left ventricular assist device (LVAD), as a mechanical circulatory support, has become a new light for patients with HF. With the technical advancements, LVADs work not only as a bridge to transplant, but also assist heart recovery and even as a destination therapy in long-term treatment. This observation paper reviewed the development of LVAD and its clinical roles. The challenges and possible solutions in nursing care for patients with LVAD at different stage of implantation were discussed. The healthcare professionals could obtain a better understanding about the LVAD treatment for HF patients.     

左心辅助对右心功能影响的实验研究

目的　比较左心辅助对正常及急性缺血性功能不全右心室血流动力学的影响 ,初步探讨左心辅助后右心衰的发生原因。方法　以左心房 -主动脉旁路方式植入左心辅助装置于健康成年犬心脏 ,以 70 %辅助流率行左心辅助 ,在辅助前后记录中心静脉压 (CVP)、心输出量 (CO)、平均动脉压 (MAP)、肺动脉压 (PAP)、右心室最大收缩压(RVSPmax)、右心室最大收缩压一阶导数 (RVdp/dtmax)。停左心辅助并结扎右冠状动脉 ,5min后再行左心辅助 ,分别在辅助前后记录上述指标。结果　在右心功能正常时 ,左心辅助后肺动脉压下降 17% (P <0 0 1) ,其他血流动力学指标无明显变化 ;在右心功能不全时行左心辅助后 ,CVP上升 2 % (P>0 0 5 ) ,CO下降 4 % (P <0 0 5 ) ,MAP下降 7% (P <0 0 5 ) ,PAP下降 33% (P <0 0 1) ,RVSPmax及RVdp/dtmax分别下降18%和 14 % (P <0 0 1)。结论　在正常及急性缺血性功能不全右心室行左心辅助后血流动力学的不同变化趋势表明 ,原已存在功能损害的右心室能否承受LVAD应用后所产生的血流动力学的变化是左心辅助应用后发生右心衰的主要原因     

Chronic outpatient management of patients with a left ventricular assist device

The use of mechanical circulatory support (MCS) as treatment for advanced heart failure (HF) has grown exponentially over the past 15 years. The continuous flow left ventricular assist device (CF-LVAD) has become the most used form of MCS in advanced HF, especially since approval of use as destination therapy (DT) and with the lack of organ availability. Long-term survival has improved and diligent outpatient management is thus particularly critical to achieve optimal outcomes. This review will discuss outpatient management strategies for patients with HF and a left ventricular assist device (LVAD).     

新型国产隔膜气动左心辅助泵(罗叶泵)的临床试用

目的 总结新型国产隔膜气动左心辅助泵（罗叶泵）临床试用4例病人的经验。临床资料及结果 本组4例病人均为心脏手术后严重低心排出量综合征病人，其中1例合并围术期急性心肌梗死。3例应用主动脉内球囊反博（IABP）效果不满意再行左心辅助，1例直接行左心辅助。左心辅助时间30.3-116h，平均78.1h。本组死亡3例，1例死于肾功能衰竭，1例死于多脏器官功能衰竭，1例死于脑出血。本组存活1例，左心辅助期间出现左颞叶和顶叶脑梗死，右侧肢体偏瘫，经治疗后好转出院，随访6个月，右侧肢体活动明显改善，一般情况尚好。结论 新型国产隔膜气动左心辅助泵（罗叶泵）在抢救心脏手术后严重低心排出量综合征中显示能效满意地维持血流动力学的稳定，有较IABP更显的效果。在应用时要把握时机，尽早应用。然后，左心辅助的应用仍存在安置较为复杂，易渗血等不足之处，有待今后进一步总结经验，加以改进，使国产辅助装置在我国得以更广泛地应用。