Outcomes After Heartmate 3 Left Ventricular Assist Device Implantation Using a 10 mm Outflow Graft

The presence of adhesions and patent bypass grafts may create challenges for standard 14 mm outflow graft placement during left ventricular assist device implantation. We retrospectively describe our experience using a 10 mm Bioline Fusion graft (Getinge, Goteborg, Sweden) as the outflow graft in patients undergoing primary Heartmate 3 (Abbott, Abbott Park, IL) implantation. One hundred one patients underwent Heartmate 3 left ventricular assist device implantation, 80% via a thoracotomy approach, with the standard 14 mm outflow graft (78) or a 10 mm Bioline Fusion outflow graft (23). Initial postoperative rotor speed-to-flow ratio (the revolutions per minutes (RPMs) required to achieve a given flow) was significantly higher in 10 mm graft patients (1,472 vs. 1,283 RPM/L/min; p = 0.03), suggesting elevated resistance in the smaller graft. Furthermore, the initial postoperative vasoactive-inotrope score was higher in the 10 mm graft patients (24.1 vs. 17.6; p = 0.022). Postoperative outcomes were similar between groups. In conclusion, the use of a 10 mm graft was associated with higher RPMs needed to generate a given flow and a higher vasoactive-inotrope score, but these differences were not associated with increased right ventricular failure or mortality.

Right Ventricular Function Following Sternotomy Versus a Less-Invasive Approach for Left Ventricular Assist Device Implant: Retrospective Cohort Study

OBJECTIVES

Durable left ventricular assist device (LVAD) implantation is traditionally performed via median sternotomy (MS). Less-invasive implantation may lower the incidence of postimplant right ventricular failure (RVF). Our primary objective was to determine whether less-invasive implantation reduces the odds of severe RVF compared to MS.

DESIGN

Retrospective cohort study.

SETTING

St. Paul's Hospital, Vancouver, BC, Canada.

PARTICIPANTS

One hundred ninety-eight adult patients between January 2008 and August 2021.

INTERVENTIONS

Isolated LVAD implantation either via median sternotomy or via a less-invasive surgical approach.

MEASUREMENTS AND MAIN RESULTS

Multivariable logistic regression was used to adjust for confounders. A sensitivity analysis using inverse probability of treatment weighting analysis based on propensity scores was conducted. One hundred seventy-two patients were analyzed; 54% (94/172) underwent LVAD implantation via MS, and 45% (78/172) via less-invasive approaches. Age, sex, and comorbidities were comparable, but the MS group tended to be more critically ill prior to surgery. After adjusting for confounders, less-invasive approaches did not show significant protection against severe postimplant RVF compared to MS (adjusted odds ratio 0.53; 95% confidence interval 0.20-1.44; p = 0.21). However, patients undergoing less-invasive techniques had reduced adjusted odds of 30-day mortality (odds ratio 0.29; 95% confidence interval 0.09-0.99); p = 0.049). There was no observed benefit of less-invasive approaches over MS for major bleeding, prevention of blood product transfusion, and listing for transplantation.

CONCLUSIONS

There was no reduction in the odds of severe RVF following LVAD implantation using less-invasive approaches versus MS. However, we found improved odds of 30-day survival in the less-invasive group. The underlying mechanism requires further investigation.

Deactivation of LVAD support for myocardial recovery-surgical perspectives

Left ventricular assist devices (LVADs) are excellent therapies for advanced heart failure patients either bridged to transplant or for lifetime use. LVADs also allow for reverse remodeling of the failing heart that is often associated with functional improvement. Indeed, growing enthusiasm exists to better understand this population of patients, whereby the LVAD is used as an adjunct to mediate myocardial recovery. When patients achieve benchmarks suggesting that they no longer need LVAD support, questions related to the discontinuation of LVAD therapy become front and center. The purpose of this review is to provide a surgical perspective on the practical and technical issues surrounding LVAD deactivation.

Intracardiac Shunt Reversal and Early Right Ventricular Failure after Left Ventricular Assist Device Implantation

Right ventricular failure (RVF) is a common complication that occurs after a left ventricular assist device (LVAD) is implanted. We report an interesting case of severe and refractory hypoxia during the early postoperative period after HeartMate3 (HM3) (Abbott Laboratories, Lake Forest, IL) implantation resulting in the unmasking of a right-to-left intracardiac shunt through a patent foramen ovale (PFO), triggered by early RVF. Importantly, the patient had a small left-to-right shunt after receiving a left-sided Impella 5.5 micro-axial pump (Abiomed, Danvers, MA, USA) pre-LVAD implantation. We observed improved hypoxia but worsening RVF after percutaneous PFO closure, necessitating right-sided mechanical circulatory support. We outline potential reasons for the significant PFO-related shunting seen after HM3 implantation, but not after Impella 5.5 placement. Uncertainty exists regarding the approach to a PFO in patients undergoing LVAD implantation. We propose an approach based on existing literature.

Robotically assisted outflow graft anastomosis in minimally invasive left-ventricular assist device implantation: feasibility, surgeon comfort, and operative times in an anatomical study

Upper hemi-sternotomy is a common approach for outflow graft anastomosis to the ascending aorta in minimally invasive left-ventricular assist device implantation. Right mini-thoracotomy may also be used, but use of robotic assistance has been reported only anecdotally. The aim of our study was to confirm the feasibility of robotically assisted suturing of the outflow graft anastomosis and to assess performance metrics for the robotic suturing part of the procedure. The procedure was carried out in eight cadaver studies by two surgeons. The assist device pump head was inserted through a left-sided mini-thoracotomy and the outflow graft was passed toward a right-sided second interspace mini-thoracotomy through the pericardium. After placement of a partial occlusion clamp on the ascending aorta, a longitudinal aortotomy was performed and the outflow graft to ascending aorta anastomosis was carried out robotically. The procedure was feasible in all eight attempts. The mean outflow graft anastomotic time was 20.1 (SD 6.8) min and the mean surgeon confidence and comfort levels to complete the anastomoses were 8.3 (SD 2.4) and 6.9 (SD2.2), respectively, on a ten-grade Likert scale. On open inspection of the anastomoses, there was good suture alignment in all cases. We conclude that suturing of a left-ventricular assist device outflow graft to the human ascending aorta is very feasible with good surgeon comfort. Anastomotic times are acceptable and suture placement can be performed with appropriate alignment.

The Results of Minimally Invasive Implantation of the HeartMate 3 LVAD Left Ventricular Assist Device

OBJECTIVE

To evaluate the safety, feasibility and effectiveness of minimally invasive HeartMate 3 LVAD implantation.

METHODOLOGY

Forty-seven patients who underwent the HeartMate 3 LVAD implantation by sternotomy and 26 ones who had implantation via minimally invasive method were analyzed. The observation lasted from November 2016 to May 2020.

RESULTS

ECMO as a bridge to LVAD, was more usual in the sternotomy group (11% vs 0%, P = .03). In the minimally invasive group, a history of previous cardiac surgery was more common (54% vs 12%, P < .001), this was the main indication for a minimally invasive approach in our institution. Patients undergoing a minimally invasive implantation had a significantly longer duration of surgery (Med. = 367.5 min vs Med. = 265.0 minutes, P < .001), and significantly higher intraoperative use of fresh frozen plasma (FFP) and platelet concentrates (PCs). There was no significant difference in the number of postoperative bleedings requiring surgical intervention. Postoperative wound infections were observed significantly more often in the sternotomy group (6% vs 0.0%, P < .001). There was no significant difference in survival between groups in the first 180 days after surgery. A slightly lower percentage of patients reached 2-year postsurgery survival in the group undergoing sternotomy, but this finding was not statistically significant. The mean survival time among sternotomy patients was 430.0 days (+/- 291.77 days) vs 633.15 days (+/- 426.84) in minimally invasive group.

CONCLUSIONS

Minimally invasive implantation of the HeartMate 3 LVAD may be an alternative method of LVAD implantation in a selected group of patients.

Off-pump implantation of left ventricular assist device via minimally invasive left thoracotomy: Our single-center experience

Background

The aim of this study was to compare our experience of left ventricular assist device implantation via minimally invasive left thoracotomy with off-pump versus on-pump technique.

Methods

Between June 2013 and April 2020, nine patients (8 males, 1 female; mean age: 47±11.9 years; range, 30 to 61 years) who underwent off-pump left ventricular assist device implantation and nine patients (8 males, 1 female; mean age: 47±11.4 years; range, 29 to 60 years) who underwent on-pump minimally invasive left thoracotomy were retrospectively analyzed. Postoperative outcomes and mid-term results of both groups were evaluated.

Results

Outflow graft was anastomosed to the ascending aorta with J-sternotomy in all patients. The median duration of intubation and intensive care unit stay were one (IQR: 1.5) day and eight (IQR: 6.5) days in the off-pump group, respectively and one (IQR: 0) day and seven (IQR: 7) days in the on-pump group, respectively. Intra-aortic balloon pump was needed during the weaning of cardiopulmonary bypass in one (11%) of the patients in both groups. Postoperative right ventricular failure was observed in two (22%) patients in the offpump group who were treated medically and recovered. There was no need for revision due to bleeding or postoperative extracorporeal membrane oxygenator implantation in either group. In the off-pump group, three patients underwent heart transplantation after median 854 (IQR: 960) days. Three patients died one month, two and four years after implantation. Three patients were still alive with left ventricular assist device and were being uneventfully followed for 365, 400, and 700 days after implantation.

Conclusion

Off-pump technique is safe and feasible option for implantation of left ventricular assist device via minimally invasive left thoracotomy.

Right heart failure after left ventricular assist device: From mechanisms to treatments

Left ventricular assist device (LVAD) therapy is a lifesaving option for patients with medical therapy-refractory advanced heart failure. Depending on the definition, 5-44% of people supported with an LVAD develop right heart failure (RHF), which is associated with worse outcomes. The mechanisms related to RHF include patient, surgical, and hemodynamic factors. Despite significant progress in understanding the roles of these factors and improvements in surgical techniques and LVAD technology, this complication is still a substantial cause of morbidity and mortality among LVAD patients. Additionally, specific medical therapies for this complication still are lacking, leaving cardiac transplantation or supportive management as the only options for LVAD patients who develop RHF. While significant effort has been made to create algorithms aimed at stratifying risk for RHF in patients undergoing LVAD implantation, the predictive value of these algorithms has been limited, especially when attempts at external validation have been undertaken. Perhaps one of the reasons for poor performance in external validation is related to differing definitions of RHF in external cohorts. Additionally, most research in this field has focused on RHF occurring in the early phase (i.e., ≤1 month) post LVAD implantation. However, there is emerging recognition of late-onset RHF (i.e., > 1 month post-surgery) as a significant cause of morbidity and mortality. Late-onset RHF, which likely has a unique physiology and pathogenic mechanisms, remains poorly characterized. In this review of the literature, we will describe the unique right ventricular physiology and changes elicited by LVADs that might cause both early- and late-onset RHF. Finally, we will analyze the currently available treatments for RHF, including mechanical circulatory support options and medical therapies.

Impact of surgical approach for left ventricular assist device implantation on postoperative invasive hemodynamics and right ventricular failure

BACKGROUND

Right ventricular failure (RVF) remains one of the major causes of morbidity and mortality after left ventricular assist device (LVAD) implantation. We sought to compare immediate postoperative invasive hemodynamics and the risk of RVF following two different surgical approaches: less invasive surgery (LIS) versus full sternotomy (FS).

METHODS

The study population comprised all 231 patients who underwent implantation of a HeartMate 3 (Abbott) LVAD at our institution from 2015 to 2020, utilizing an LIS (n = 161; 70%) versus FS (n = 70; 30%) surgical approach. Outcomes included postoperative invasive hemodynamic parameters, vasoactive-inotropic score (VIS), RVF during index hospitalization, and 6-month mortality.

RESULTS

Baseline clinical characteristics of the two groups were similar. Multivariate analysis showed that LIS, compared with FS, was associated with the improved cardiac index (CI) at the sixth postoperative hour (p = .036) and similar CI at 24 h, maintained by lower VIS at both timepoints (p = .002). The LIS versus FS approach was also associated with a three-fold lower incidence of in-hospital severe RVF (8.7% vs. 28.6%, p < .001) and need for RVAD support (5.0% vs. 17.1%, p = .003), and with 68% reduction in the risk of 6-month mortality after LVAD implantation (Hazard ratio, 0.32; CI, 0.13-0.78; p = .012).

CONCLUSION

Our findings suggest that LIS, compared with FS, is associated with a more favorable hemodynamic profile, as indicated by similar hemodynamic parameters maintained by lower vasoactive-inotropic support during the acute postoperative period. These findings were followed by a reduction in the risk of severe RVF and 6-month mortality in the LIS group.

When Nothing Goes Right: Risk Factors and Biomarkers of Right Heart Failure after Left Ventricular Assist Device Implantation

Right heart failure (RHF) is a severe complication after left ventricular assist device (LVAD) implantation. The aim of this study was to analyze the incidence, risk factors, and biomarkers for late RHF including the possible superiority of the device and implantation method. This retrospective, single-center study included patients who underwent LVAD implantation between 2014 and 2018. Primary outcome was freedom from RHF over one-year after LVAD implantation; secondary outcomes included pre- and postoperative risk factors and biomarkers for RHF. Of the 145 consecutive patients (HeartMate 3/HVAD: n = 70/75; female: 13.8%), thirty-one patients (21.4%) suffered RHF after a mean LVAD support of median (IQR) 105 (118) days. LVAD implantation method (less invasive: 46.7% vs. 35.1%, p = 0.29) did not differ significantly in patients with or without RHF, whereas the incidence of RHF was lower in HeartMate 3 vs. HVAD patients (12.9% vs. 29.3%, p = 0.016). Multivariate Cox proportional hazard analysis identified HVAD (HR 4.61, 95% CI 1.12-18.98; p = 0.03), early post-op heart rate (HR 0.96, 95% CI 0.93-0.99; p = 0.02), and central venous pressure (CVP) (HR 1.21, 95% CI 1.05-1.39; p = 0.01) as independent risk factors for RHF, but no association of RHF with increased all-cause mortality (HR 1.00, 95% CI 0.99-1.01; p = 0.50) was found. To conclude, HVAD use, lower heart rate, and higher CVP early post-op were independent risk factors for RHF following LVAD implantation.

Combining Minimally Invasive Surgery With Ultra-Fast-Track Anesthesia in HeartMate 3 Patients: A Pilot Study

BACKGROUND

Minimally invasive surgery for left ventricular assist device implantation may have advantages over conventional sternotomy (CS). Additionally, ultra-fast-track anesthesia has been linked to better outcomes after cardiac surgery. This study summarizes our early experience of combining minimally invasive surgery with ultra-fast-track anesthesia (MIFTA) in patients receiving HeartMate 3 devices and compares the outcomes between MIFTA and CS.

METHODS

From October 2015 to January 2019, 18 of 49 patients with Interagency Registry for Mechanically Assisted Circulatory Support profiles >1 underwent MIFTA for HeartMate 3 implantation. For bias reduction, propensity scores were calculated and used as a covariate in a regression model to analyze outcomes. Weighted parametric survival analysis was performed.

RESULTS

In the MIFTA group, intensive care unit stays were shorter (mean difference, 8 days [95% CI, 4-13]; P<0.001), and the incidences of pneumonia and right heart failure were lower than those in the CS group (odds ratio, 1.36 [95% CI, 1.01-1.75]; P=0.016, respectively). At 6 and 12 hours postoperatively, MIFTA patients had a better hemodynamic performance with lower pulmonary wedge pressure (mean difference, 2.23 mm Hg [95% CI, 0.41-4.06]; P=0.028) and a higher right ventricular stroke work index (mean difference, -1.49 g·m/m² per beat [95% CI, -2.95 to -0.02]; P=0.031). CS patients had a worse right heart failure-free survival rate (hazard ratio, 2.35 [95% CI, 0.96-5.72]; P<0.01).

CONCLUSIONS

Compared with CS, MIFTA is a beneficial approach for non-Interagency Registry for Mechanically Assisted Circulatory Support 1 HeartMate 3 patients with lower adverse event incidences, better hemodynamic performance, and preserved right heart function. Future large multicentric investigations are required to verify MIFTA's effects on outcomes.

Continuous-flow left ventricular assist device: Current knowledge, complications, and future directions

Long-term continuous-flow left ventricular assist devices have become a real alternative to heart transplantation in patients with advanced heart failure, achieving a promising 2-year event-free survival rate with new-generation devices. Currently, this technology has spread throughout the world, and any cardiologist or cardiac surgeon should be familiar with its fundamentals and its possible complications as well as the advances made in recent years. The aim of this review is to describe current knowledge, management of complications, and future directions of this novel heart-failure therapy.

Physiology of Continuous-Flow Left Ventricular Assist Device Therapy

The expanding use of continuous-flow left ventricular assist devices (CF-LVADs) for end-stage heart failure warrants familiarity with the physiologic interaction of the device with the native circulation. Contemporary devices utilize predominantly centrifugal flow and, to a lesser extent, axial flow rotors that vary with respect to their intrinsic flow characteristics. Flow can be manipulated with adjustments to preload and afterload as in the native heart, and ascertainment of the predicted effects is provided by differential pressure-flow (H-Q) curves or loops. Valvular heart disease, especially aortic regurgitation, may significantly affect adequacy of mechanical support. In contrast, atrioventricular and ventriculoventricular timing is of less certain significance. Although beneficial effects of device therapy are typically seen due to enhanced distal perfusion, unloading of the left ventricle and atrium, and amelioration of secondary pulmonary hypertension, negative effects of CF-LVAD therapy on right ventricular filling and function, through right-sided loading and septal interaction, can make optimization challenging. Additionally, a lack of pulsatile energy provided by CF-LVAD therapy has physiologic consequences for end-organ function and may be responsible for a series of adverse effects. Rheological effects of intravascular pumps, especially shear stress exposure, result in platelet activation and hemolysis, which may result in both thrombotic and hemorrhagic consequences. Development of novel solutions for untoward device-circulatory interactions will facilitate hemodynamic support while mitigating adverse events. © 2021 American Physiological Society. Compr Physiol 12:1-37, 2021.

Effect of preoperative erector spinae muscles mass on postoperative outcomes in patients with left ventricular assist devices

BACKGROUND

Frailty influences the postoperative outcomes in patients undergoing left ventricular assist device (LVAD) implantation. Recently, erector spinae muscle (ESM) mass has been proposed as a parameter to assess frailty accurately. Thus, the purpose of the present study was to evaluate whether preoperative ESM mass is associated with short- and long-term clinical outcomes in patients with LVAD.

METHODS

A total of 119 consecutive patients with LVAD were enrolled between January 2010 and October 2017 at a single heart center. The ESM area, ESM index, and Hounsfield units (HU) of the ESM were calculated by computed tomography for preoperative ESM mass evaluation. We then statistically evaluated the in-hospital mortality, major adverse cardiovascular events (MACE), duration of hospital stay, and long-term survival.

RESULTS

In a multivariate Cox regression analysis, ESM mass indicated no effect on all clinical outcomes. In addition, the ESM area presented a weak but significant negative linear correlation only with the duration of hospital stay (r = -0.21, p < .05). In contrast, the Model For End-stage Liver Disease (MELD) score and preoperative venous-arterial extracorporeal membrane oxygenation (va-ECMO) were significant predictive factors for in-hospital mortality (MELD score: p < .001, hazard ratio [HR] 1.1; preoperative va-ECMO: p < .01, HR 2.72) and MACE (MELD score: p < .001, HR 1.07; preoperative va-ECMO: p < .005, HR 2.62).

CONCLUSION

Preoperative ESM mass might predict the length of hospital stay in patients undergoing LVAD implantation. In contrast, it had no effect on MACE, in-hospital mortality, or long-term survival in this study.

Heart Transplant and Ventricular Assist: Cardiac Surgery and Heart Failure Perspective

For nearly 60 years, there have been two surgical treatment options for individuals with severe advanced heart failure: heart transplantation or implantation of a left ventricular assist device. As these fields have advanced in parallel, improvements in surgical technique, device development, and patient selection have improved outcomes for both therapies. Development of a comprehensive approach to the management of the most severe forms of advanced heart failure requires a deep understanding of both heart transplantation and durable ventricular assistance, including recent advancements in both fields. This article will review the substantial progress in the fields of heart transplantation and mechanical left ventricular assistance, including recent changes to organ allocation prioritization and left ventricular assist device evaluation, both of which have dramatically influenced practice in these fields.

Inflow Cannula Position Influences Improvement in Mitral Regurgitation After Ventricular Assist Device Implantation

Significant residual mitral regurgitation (MR) after left ventricular assist device (LVAD) implantation has been associated with increased morbidity and mortality. The effect of cannula position on improvement of preexisting MR has yet to be evaluated. Consecutive patients who underwent centrifugal LVAD implantation with >mild preoperative MR and without concomitant mitral repair were reviewed. Left ventricular assist device position was determined by the angle between actual and ideal inflow cannula on computed tomography. The magnitudes of angles (anterior and lateral angle) were added to form an LVAD position assessment (LVADpa). Mitral regurgitation was numerically classified, and improvement in MR was determined by difference in MR preoperatively to MR >1 month postoperatively with a median of 162 (interquartile range: 78-218) days. The primary analysis examined the relationship between LVADpa and postoperative MR. Forty-one patients were identified with >mild preoperative functional MR. Mean age was 51 ± 13 years with an ejection fraction of 16 ± 4%. Overall, MR improved from moderate-severe preoperatively to mild postoperatively (p < 0.001). On multivariable analysis, higher LVADpa deviation was associated with greater postoperative MR (odds ratio [OR] = 2.29, p = 0.005) and higher 1-month pulsatility index was associated with lower postoperative MR (OR = 0.47, p = 0.011). Inflow cannula position during centrifugal LVAD implantation is an important determinant of postoperative MR.

Thoracotomy versus sternotomy? The effect of surgical approach on outcomes after left ventricular assist device implantation: A review of the literature and meta-analysis

BACKGROUND AND AIM

Thoracotomy approaches to left ventricular assist device (LVAD) implantation may reduce surgical morbidity and, through preservation of the pericardial restraint over the right heart, may reduce the incidence of right ventricular failure (RVF).

METHODS

A meta-analysis of all original studies describing the effect of the surgical approach on postoperative outcomes after LVAD implantation was performed. Postoperative outcomes analyzed.

RESULTS

Thirteen studies were included with 692 patients undergoing a sternotomy and 373 a thoracotomy approach. Patients undergoing a thoracotomy approach had a higher comorbid status (INTERMACS 1-2: 56% vs. 44%; p = .0004), but were less likely to undergo a concomitant procedure (4% vs. 15%; p = .0002) than patients undergoing a sternotomy approach. Patients undergoing a thoracotomy approach demonstrated a reduced incidence of RVF (OR, .47; CI, .23-.97; p = .04), reexploration for bleeding (OR, .55; CI, .32-.94; p = .03), perioperative blood transfusion (SMD, -.30; CI, -.49 to -.11; p = .002), LOS (-5.57; -10.56 to -.59; p = .03), and mortality (OR, .57; CI, .33-.98; p = .04), but no difference in RVAD requirement or stroke were noted. Metaregression demonstrated that the performance of a concomitant procedure did not modify the effect of the surgical approach on the primary endpoints of RVF or RVAD requirement.

CONCLUSIONS

In the current meta-analysis including over 1000 patients undergoing LVAD implantation, a thoracotomy approach was associated with a reduced incidence of RVF (but not RVAD requirement), bleeding, LOS, and mortality. No difference in stroke rates was noted. These findings not only offer additional support as to the feasibility of a thoracotomy approach for LVAD implantation but also suggest a potential superiority over a sternotomy approach.

Minimally invasive versus conventional continuous-flow left ventricular assist device implantation for heart failure: a meta-analysis

Many studies have reported various minimally invasive techniques for continuous-flow left ventricular assist device implantation. There is no consensus on whether minimally invasive techniques can bring more benefits for patients compared with the conventional technique, due to the limited number of patients and diverse results in current studies. Our meta-analysis mainly discussed the comparison of minimally invasive and conventional techniques. We searched controlled trials from PubMed, Cochrane Library, and Embase databases until Dec 11, 2020. Perioperative and postoperative outcomes were analyzed among 10 included studies. The protocol has been registered with PROSPERO (CRD42020221532). There were no statistical differences in the 30-day mortality (OR 0.57; 95% CI 0.29 to 1.14), 6-month mortality (OR 0.66; 95% CI 0.41 to 1.05), neurological dysfunction (OR 1.10; 95% CI 0.69 to 1.76), major infection (OR 0.68; 95% CI 0.36 to 1.28), and pump thrombus (OR 1.49; 95% CI 0.63 to 3.52) among the cohorts. Minimally invasive techniques were associated with lower incidences of major bleeding (OR 0.39; 95% CI 0.22 to 0.68), severe right heart failure (OR 0.43; 95% CI 0.23 to 0.81), and less blood-product utilization (SMD -0.44). Sensitivity analysis suggested that minimally invasive techniques were associated with a lower incidence of respiratory failure (OR 0.50; 95% CI 0.26 to 0.96) and shorter mechanical ventilation time (SMD -0.53). Subgroup analysis demonstrated that patients, implanted with a centrifugal pump by minimally invasive techniques, were associated with a shorter length of intensive care unit (ICU) stay (SMD -0.27) and hospital stay (SMD -0.42), and less blood-product utilization (SMD -0.26). In conclusion, minimally invasive techniques can reduce the risks of major bleeding, severe right heart failure, and blood-product utilization, as well as have positive impacts on reducing mechanical ventilation time and the risk of respiratory failure. Minimally invasive centrifugal pump implantation can reduce the length of ICU and hospital stay.

Left thoracotomy vs full sternotomy for centrifugal durable LVAD implantation: 1-year outcome comparison post-LVAD and post-heart transplantation

Left ventricular assist device (LVAD) implantations have traditionally been approached through a full median sternotomy (FS). Recently, a minimally invasive left thoracotomy (LT) approach has been popularized. This study sought to compare the outcomes of FS and LT patients post-primary LVAD implantation and post-subsequent heart transplant (HT). This was a single-center retrospective study. 83 patients who underwent primary centrifugal durable LVAD implantation from January 2014 to June 2018 were included (FS, n = 41; LT, n = 42). 41 patients had a subsequent HT (FS, n = 19; LT, n = 22). Pre-operative patient demographics, intraoperative variables, post-operative 1-year survival, length of hospital stay, complications, and outcomes for LVAD implantation and following HT were analyzed. Intraoperative data showed that the LT group had a 23.4% longer mean LVAD implant surgical time (p < 0.01). One-year post-LVAD survival was similar between the two groups (p = 0.05). Complication rates, with the exception of the rate of hemorrhagic stroke (p = 0.04) post-LVAD implant were similar. One-year survival post-HT was similar between groups (p = 0.35). Complication rates and mean length of hospital stay were also similar (p = 1.0) post-HT. Our study demonstrated that LT approach does not negatively affect post-LVAD implantation or post-HT outcomes. Further, larger studies may determine more detailed effects of LT approach.

Sex differences in outcomes following less-invasive left ventricular assist device implantation

Background

Worse outcomes in women compared to men undergoing left ventricular assist device (LVAD) implantation remain an underestimated problem in heart failure (HF) patients. With device miniaturization, less-invasive LVAD implantation techniques have gained relevance, but their impact on outcomes in women is unknown. This study investigates sex-related differences in patients undergoing LVAD implantation through less-invasive procedures.

Methods

This retrospective single-center cohort study included patients who underwent isolated LVAD implantation between 2011 and 2018 through less-invasive techniques. Propensity score matching (PSM) was utilized to balance preoperative heterogeneity. Primary endpoint was two-year survival, and secondary endpoints included long-term survival, surgical outcomes and postoperative adverse events.

Results

Baseline analysis of 191 patients (females 18.3%) showed differences in terms of age [female (median, 52; IQR, 47-61); male (median, 58.5; IQR, 49-66); P=0.005], underlying diagnosis (P<0.001), INTERMACS profile (P=0.009), history of previous cardiac surgery (P=0.049) and preoperative creatinine values [female (median, 110; IQR, 71-146); male (median, 126; IQR, 9-168); P=0.049]. Over a follow-up of 460.68 patient-years, Kaplan-Meyer analysis showed better survival in females (P=0.027) and a similar probability of cardiac transplantation (P=0.288). After PSM, females showed higher needs for intraoperative fresh frozen plasma (P=0.044) and platelets (P=0.001) but comparable postoperative outcomes. No sex-related differences were noticed regarding two-year outcomes, long-term survival and adverse events. LVAD-related infections remained the most common complication with males experiencing more pump infections than women (P=0.050).

Conclusions

Patients receiving less-invasive LVAD implantation do not show significant sex-related differences in short and long-term outcomes and survival. Prospective studies are needed to evaluate the role of less-invasive techniques in reducing sex-based disparities after LVAD implantation.

Minimally invasive ventricular assist device implantation

Durable mechanical circulatory support (MCS) systems are established therapy option in patients with end-stage heart failure, with increasing importance during the last years due to donor organ shortage. Left ventricular assist devices (LVADs) are traditionally implanted through median sternotomy (MS). However, improvement in the pump designs during the last years led to evolvement of new surgical approaches that aim to reduce the invasiveness of the procedure. Numerous reports and studies have shown the viability and possible advantages of less-invasive approach compared to the sternotomy approach. The less invasive implant strategies for LVADs, while vague in definition, are characterized by minimizing surgical trauma and if possible, cardio-pulmonary bypass related complications. Usually it involves minimizing or completely avoiding sternal trauma, avoiding heart luxation while simultaneously leaving the major part of pericardium intact. There is no consensus between the centers regarding the ideal approach for LVAD implantation. Some centers, like our center, perform by default VAD implantation using less invasive approach in almost all patients and some centers use only sternotomy approach. The aim of this review article is to shed light on the currently available less invasive options of LVAD implantation, with particular focus on the centrifugal pumps, and their possible advantages compared to traditional sternotomy approach.

Lateral Thoracotomy for Ventricular Assist Device Implantation: A Meta-Analysis of Literature

The use of lateral thoracotomy (LT) for implanting left ventricular assist devices (LVADs) is worldwide increasing, although the available evidence for its positive effects compared with conventional sternotomy (CS) is limited. This systematic review and meta-analysis analyzes the outcomes of LT compared with CS in patients undergoing implantation of a centrifugal continuous-flow LVAD. Four databases and 1,053 publications were screened until December 2019. Articles including patients undergoing implantation of a centrifugal continuous-flow LVAD through LT were included. A meta-analysis to compare LT and CS was performed to summarize evidences from studies including both LT and CS patients extracted from the same population. Primary outcome measure was in-hospital or 30-day mortality. Eight studies reporting on 730 patients undergoing LVAD implantation through LT (n = 242) or CS (n = 488) were included in the meta-analysis. Left thoracotomy showed lower in-hospital/30-day mortality (odds ratio [OR]: 0.520, 95% confidence interval [CI]: 0.27-0.99, p = 0.050), shorter intensive care unit (ICU) stay (mean difference [MD]: 3.29, CI: 1.76-4.82, p < 0.001), lower incidence of severe right heart failure (OR: 0.41; CI: 0.19-0.87, p = 0.020) and postoperative right ventricular assist device (RVAD) implantation (OR: 0.27, CI: 0.10-0.76, p = 0.010), fewer perioperative transfusions (MD: 0.75, CI: 0.36-1.14, p < 0.001), and lower incidence of renal failure (OR: 0.45, CI: 0.20-1.01, p = 0.050) and device-related infections (OR: 0.45, CI: 0.20-1.01, p = 0.050), respectively. This meta-analysis demonstrates that implantation of a centrifugal continuous-flow LVAD system via LT benefits from higher short-term survival, less right heart failure, lower postoperative RVAD need, shorter ICU stay, less transfusions, lower risk of device-related infections and kidney failure. Prospective studies are needed for further proof.

Ventricular assist devices implantation: surgical assessment and technical strategies

Along with the worldwide increase in continuous left ventricular assist device (LVAD) strategy adoption, more and more patients with demanding anatomical and clinical features are currently referred to heart failure (HF) departments for treatment. Thus surgeons have to deal, technically, with re-entry due to previous cardiac surgery procedures, porcelain aorta, peripheral vascular arterial disease, concomitant valvular or septal disease, biventricular failure. New surgical techniques and surgical tools have been developed to offer acceptable postoperative outcomes to all mechanical circulatory support recipients. Several less invasive and/or thoracotomic approaches for surgery combined with various LVAD inflow and outflow graft alternative anastomotic sites for system placement have been reported and described to solve complex clinical scenarios. Surgical techniques have been upgraded with further technical tips to preserve the native anatomy in case of re-entry for heart transplantation, myocardial recovery or device explant. The current continuous-flow miniaturized and intrapericardial devices provide versatility and technical advantages. However, the surgical planning requires a careful multidisciplinary evaluation which must be driven by a dedicated and well-trained Heart Failure team. Biventricular assist device (BVAD) implantation by adoption of the newer radial pumps might be a challenge. However, the results are encouraging thus remaining a valid option. This paper reviews and summarizes LVAD preoperative assessment and current surgical techniques for implantation.

Minimally Invasive Left Ventricular Assist Device Insertion Facilitates Subsequent Heart Transplant

OBJECTIVE

We have observed that minimally invasive left ventricular assist device (LVAD) insertion leads to more facile re-entry and easier cardiac transplantation. We hypothesize minimally invasive LVAD implantation results in improved outcomes at the time of subsequent heart transplant.

METHODS

All adults undergoing cardiac transplantation between October 2015 and March 2019 at our institution were retrospectively reviewed. Those bridged to transplantation with a HeartWare HVAD were identified and divided into 2 cohorts based upon the surgical approach: those who underwent HVAD placement by conventional sternotomy versus minimally invasive insertion via lateral thoracotomy and hemisternotomy (LTHS). Patient demographics, as well as perioperative transplant outcomes, including survival, length of stay (LOS), blood utilization, ischemic time, bypass time, and postoperative extracorporeal membrane oxygenation (ECMO) were compared between cohorts.

RESULTS

Forty-two patients were bridged to heart transplant with a HVAD implanted via either sternotomy (n = 22) or LTHS technique (n = 20). Demographics were similar between groups. There was 1 predischarge death in the sternotomy group and none in the LTHS group. Body surface area, cardiopulmonary bypass time, ischemic time, ECMO utilization, and reoperation for bleeding were similar. Red blood cell units transfused were significantly lower in the LTHS cohort (3.0 [1.0-5.0] vs 6.0 [2.5-10.0] P = 0.046). The LTHS cohort had a significantly shorter hospital LOS (12.0 [11.0-28.0] vs 22.5 [15.7-41.7] P = 0.022) with a trend toward shorter intensive care unit LOS (6.0 [5.0-10.5] vs 11.0 [6.0-21.5] days P = 0.057).

CONCLUSIONS

Minimally invasive HVAD implantation improves outcomes at subsequent heart transplantation, resulting in shorter LOS and less red cell transfusion. Larger multi-institutional studies are necessary to validate these findings.

Expert Consensus Paper: Lateral Thoracotomy for Centrifugal Ventricular Assist Device Implant

BACKGROUND

The increasing prevalence of heart failure has led to the expanded use of left ventricle assist devices (VADs) for end-stage heart failure patients worldwide. Technological improvements witnessed the development of miniaturized VADs and their implantation through less traumatic non-full sternotomy approaches using a lateral thoracotomy (LT). Although adoption of the LT approach is steadily growing, a lack of consensus remains regarding patient selection, details of the surgical technique, and perioperative management. Furthermore, the current literature does not offer prospective randomized studies or evidence-based guidelines for LT-VAD implantation.

METHODS

A worldwide group of LT-VAD experts was convened to discuss these key topics openly. After a PubMed search and review with all authors, a consensus was reached and an expert consensus paper on LT-VAD implantation was developed.

RESULTS

This document aims to guide clinicians in the selection of patients suitable for LT approaches and preoperative optimization. Details of operative techniques are described, with an overview of hemisternotomy and bilateral thoracotomy approaches. A review of the best surgical practices for placement of the pump, inflow cannula, and outflow graft provides advice on the best surgical strategies to avoid device malpositioning while optimizing VAD function. Experts' opinions on cardiopulmonary bypass, postoperative management, and approaches for pump exchange and explant are presented. This review also emphasizes the critical need for multidisciplinary teams and specific training.

CONCLUSIONS

This expert consensus review provides a compact guide to LT for VAD implantation, from patient selection through intraoperative tips and postoperative management.

A Minimally Invasive Approach to Left Ventricular Assist Device Insertion Facilitates Subsequent Explant

A minimally invasive approach to left ventricular assist device (LVAD) insertion may benefit patients at the time of implant, but whether the approach to LVAD insertion influences the outcome of subsequent cardiovascular reoperations is unknown. Here we present the case of a 50-year-old male who underwent LVAD insertion through a minimally invasive approach and subsequently had left ventricular recovery. LVAD explant was performed without the use of any blood products or inotropic support. This case demonstrates that a minimally invasive approach to LVAD insertion may also facilitate subsequent device explant.

Outcomes with temporary mechanical circulatory support before minimally invasive centrifugal left ventricular assist device

BACKGROUND

Despite improved survival and morbidity after durable left ventricular assist device (dLVAD), outcomes for cardiogenic shock patients are suboptimal. Temporary mechanical circulatory support (tMCS) can permit optimization before dLVAD. Excellent outcomes have been observed using minimally-invasive dLVAD implantation. However, some feel tMCS contraindicates this approach. To evaluate whether left thoracotomy/hemisternotomy (LTHS) dLVAD placement is safe in this setting, we compared patients who did and did not require tMCS.

METHODS

Outcomes for patients receiving dLVADs via LTHS were compared among those bridged with extracorporeal membrane oxygenation (ECMO), intra-aortic balloon pump (IABP), or no tMCS. We evaluated demographics, comorbidities, laboratory and hemodynamic data, and intraoperative and postoperative outcomes.

RESULTS

Eighty-three patients underwent LTHS dLVAD placement. Fifty did not require tMCS, while 22 (26%) required IABP, and 11 (13%) ECMO. Non-tMCS patients were primarily Intermacs 3 (56%), while IABP recipients were mainly Intermacs 2 (45%). All patients with ECMO were Intermacs 1. Patients with tMCS had worse end-organ function. Operative outcomes were similar except more concomitant procedures and red-cell transfusions in patients with ECMO. Intensive care unit and hospital length of stay and inotrope duration were also similar. There were no differences in bleeding, stroke, and infection rates. Three- and 12-month survival were: no tMCS: 94%, 86%; IABP: 100%, 88%; and ECMO: 81%, 81% (P = .45).

CONCLUSIONS

Patients with cardiogenic shock can safely undergo LTHS dLVAD implantation after stabilization with ECMO or IABP. Outcomes and complications in these patients were comparable to a less severely ill cohort without tMCS.

Less Invasive Reoperative Ventricular Assist Device Insertion for Patients With Patent Bypass Grafts

We report our technique for left ventricular assist device insertion that is useful in patients with patent coronary artery bypass grafts or mediastinal adhesions from other previous surgeries. An inverted-T upper hemisternotomy is made at the level of the second or third intercostal space, and with the left sternal section retracted, dissection is carried along the chest wall into the left pleural space. The device is implanted in the left ventricular apex via a left thoracotomy in the fifth or sixth intercostal space. The outflow graft is routed through the left pleural space and anastomosed to the ascending aorta.

Less Invasive Approach to Left Ventricular Assist Device Implantation May Improve Survival in High-Risk Patients

OBJECTIVE

Despite improvement in outcomes after left ventricular assist device (LVAD) implantation over the past 2 decades, high-risk recipients continue to have a prohibitive rate of morbidity and mortality. We hypothesized that a less invasive approach to LVAD implantation would be associated with improved survival compared to a conventional approach in this high-risk cohort.

METHODS

All consecutive LVAD recipients (2013 to 2017) that underwent centrifugal LVAD implantation were retrospectively reviewed. Patients were classified as high-risk if INTERMACS 1 or required temporary VAD/venoarterial extracorporeal membrane oxygenation prior to durable VAD implantation. Patients were stratified into 3 groups: left thoracotomy with hemi-sternotomy (LTHS) high-risk, conventional sternotomy (CS) high-risk, and non-high-risk. The primary outcome was 1-year survival.

RESULTS

A total of 57 patients (LTHS high-risk: 11, CS high-risk: 12, non-high-risk: 34) were identified. Preoperative right ventricular failure scores, HeartMate-II mortality scores, and end-organ dysfunction were similar between the 2 high-risk groups. While operative time was similar between the 3 groups, cardiopulmonary bypass time was significantly shorter in the LTHS high-risk group compared to other groups. There was a trend toward decreased intensive care unit length of stay and ventilator time in LTHS high-risk compared to CS high-risk patients. Moreover, between these 2 groups, there was a significant decrease in temporary right VAD support (50% vs 0%, P = 0.014), and 1-year survival was significantly higher in the LTHS group (42% vs 91%, P = 0.025).

CONCLUSIONS

Less invasive LVAD implantation appears to be associated with improved survival compared to conventional LVAD implantation in high-risk patients.

Minimally invasive surgery for left ventricular assist device implantation is safe and associated with a decreased risk of right ventricular failure

Background

Right ventricular failure (RVF) after left ventricular assist device (LVAD) implantation is associated with significant mortality and morbidity. The objective of this study was to determine pre- and postoperative risk factors associated with the occurrence of RVF after LVAD implantation.

Methods

This retrospective study included 68 patients who received LVADs between 2010 and 2018 either for bridge to transplant (40 patients, 58.8%) or bridge to destination therapy (28 patients, 41.2%). RVF after LVAD implantation was defined according to the INTERMACS classification. The primary endpoint was the occurrence of RVF. The secondary endpoints were hospital mortality and morbidity and long-term survival.

Results

The majority of patients (61.8%) had an INTERMACS profile 1 (36.8%) or 2 (25.0%). The LVAD was implanted either by sternotomy (37 patients, 54.4%) or thoracotomy (31 patients, 45.6%). RVF after LVAD implantation was observed in 32 patients (47.1%). In univariate analysis, an elevated serum glutamic oxaloacetic transaminase (SGOT) (P=0.028) and a high preoperative vasoactive inotropic score (VIS) (P=0.028) were significantly associated with an increased risk of RVF, whereas the implantation of LVAD through a thoracotomy approach was associated with a significant reduction in this risk (P=0.006). The multivariate analysis demonstrated that only the thoracotomy approach was significantly associated with decreased risk of RVF (odds ratio =0.33, 95% confidence interval: 0.17–0.96; P=0.042). Hospital mortality was 53.1% and 5.6% in the RVF and control groups, respectively (P<0.0001). The incidence of stroke and postoperative acute renal failure were significantly increased in the RVF group compared with the control group. The survival after LVAD implantation was 33.5%±9.0% and 85.4%±6.0% at 1 year in the RVF and control groups, respectively (P<0.0001).

Conclusions

LVAD implantation by thoracotomy significantly reduced the risk of postoperative RVF. This surgical approach should, therefore, be favored.

Minimally invasive left ventricular assist device implantation: optimizing device design for this approach

Introduction: The global heart failure (HF) burden is expected to increase due to aging populations, increasing number of end-stage HF patients and adverse lifestyle changes. Mechanical circulatory support (MCS) devices such as left ventricular assist devices (LVADs) have become a promising treatment option for short-term and long-term circulatory support of end-stage HF patients.Areas covered: Recent developments in MCS technology have been focused on miniaturization leading to the development of minimally invasive surgical procedures for LVAD implantation. This helps overcome possible postoperative complications such as major incisions and poor outcomes due to infections, right heart failure, and bleeding. This article discusses clinical and technological developments in the field of minimally invasive procedures for LVAD implantation.Expert opinion: Most patients might benefit from minimally invasive LVAD implantation performed through a limited left lateral thoracotomy associated with an upper hemisternotomy or a right anterior thoracotomy. The thoracotomy approach can also be considered in case of pump exchange or pump explant. The success of these techniques is mainly based on the optimization of LVAD pump design, inflow cannula insertion, and outflow graft as well as driveline exit sites. The future direction of the LVAD field is likely to include less-invasive approaches and smartificial technologies.