Short-Term Experience with Off-Pump Versus On-Pump Implantation of the HeartWare Left Ventricular Assist Device

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.

Non-patient factors associated with infections in LVAD recipients: A scoping review

BACKGROUND

Infections are the most common complication in recipients of durable left ventricular assist devices (LVAD) and are associated with increased morbidity, mortality, and expenditures. The existing literature examining factors associated with infection in LVAD recipients is limited and principally comprises single-center studies. This scoping review synthesizes all available evidence related to identifying modifiable, non-patient factors associated with infections among LVAD recipients.

METHODS

Published studies were identified through searching 5 bibliographic databases: PubMed, Scopus, EMBASE, CINAHL, and Web of Science Core Collection. Inclusion criteria required examination of factors associated with infections among recipients of contemporary, implantable, continuous flow LVADs. Key study characteristics were extracted by 4 independent reviewers and current literature described narratively. The Systems Engineering Initiative for Patient Safety (SEIPS) model was used to develop a taxonomy for non-patient related factors (e.g., tasks, tools, technologies, organization, and environment) associated with infections following LVAD implantation. All analyses took place between February 2019 and May 2021.

FINDINGS

A total of 43 studies met inclusion criteria. The majority of included studies were observational (n = 37), single-center (n = 29), from the U.S. (n = 38), and focused on driveline infections (n = 40). Among the 22 evaluated sub-domains of non-patient related factors, only two: increasing center experience and establishing a silicone-skin interface at the driveline exit site, were identified as consistently being associated with a lower risk of infection.

CONCLUSION

This review identified 43 studies that described non-patient related factors associated with infection in LVAD recipients. Only two factors were consistently associated with lower infection risk in LVAD recipients: increasing experience and establishing a silicone-skin interface at driveline exit site. The large variability in reporting across multiple studied interventions limited the ability to discern their effectiveness.

Off-Pump Continuous-Flow Left Ventricular Assist Device Implantation

Continuous-flow left ventricular assist device implantation is the typical treatment for end-stage heart failure. Improvements in device engineering and technology, surgical experience and technique, and perioperative management have advanced the field, and short-term results approach those of heart transplantation. Further improvements may be achieved by minimizing adverse physiologic effects associated with cardiopulmonary bypass. Therefore, we have developed an off-pump implantation approach for continuous-flow left ventricular assist devices. We detail our surgical technique for off-pump implantation of the HeartWare device.

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.

Cost of Thoracotomy Approach: An Analysis of the LATERAL Trial

BACKGROUND

Less invasive techniques for left ventricular assist device implantation have been increasingly prevalent over past years and have been associated with improved clinical outcomes. The procedural economic impact of these techniques remains unknown. We sought to study and report economic outcomes associated with the thoracotomy implantation approach.

METHODS

The LATERAL clinical trial evaluated the safety and efficacy of the thoracotomy approach for implantation of the HeartWare centrifugal-flow ventricular assist device system (HVAD). We collected UB-04 forms in parallel to the trial, allowing analysis of index hospitalization costs. All charges were converted to costs using hospital-specific cost-to-charge ratios and were subsequently compared with Medicare cost data for the same period (2015-2016). Because thoracotomy implants were off-label for all left ventricular assist devices during that period, the Medicare cohort was assumed to consist predominately of traditional sternotomy patients.

RESULTS

Thoracotomy patients demonstrated decreased costs compared with sternotomy patients during the index hospitalization. Mean total index hospitalization costs for thoracotomy were $204,107 per patient, corresponding to 21.6% reduction (P < .001) and $56,385 savings per procedure compared with sternotomy. Across almost all cost categories, thoracotomy implants were less costly.

CONCLUSIONS

In LATERAL, a clinical trial evaluating the safety and efficacy of the thoracotomy approach for HVAD, costs were lower than those reported in Medicare patient claims occurring over the same period. Because Medicare data can be presumed to consist of predominately sternotomy procedures, thoracotomy appears less expensive than traditional sternotomy.

Anesthetic Management for Left Ventricular Assist Device Implantation Through Left Thoracotomy: Evaluation of On-Pump Versus Off-Pump

BACKGROUND

Ventricular assist devices (VADs) are alternative approaches to medical treatment in patients with acute or chronic heart failure. The goal of this study was to compare an anesthetic approach in patients undergoing implantation of a VAD with (on-pump) or without (off-pump) cardiopulmonary bypass (CPB) through left thoracotomy.

METHODS

A total of 32 patients were divided into 2 groups: on-pump (group 1) and off-pump (group 2). A standard anesthesia protocol was used in all patients. Baseline characteristics of the patients, intraoperative hemodynamic and respiratory variables, anesthetic agents and vasoactive drugs administered, the amount of blood products, extubation, length of hospital stay and intensive care unit stay, and postoperative complications were recorded.

RESULTS

Patients' mean age was 54.7 ± 13.3 years (range, 18-74 years). Eighteen patients underwent surgery with CPB. Demographic data of the patients, preoperative characteristics, intraoperative use of blood products, intraoperative complications, and anesthetic drugs used were similar between groups (P > .05). The duration of surgery (219 ± 23 vs 273 ± 56 minutes) and anesthesia (274 ± 38 vs 323 ± 57 minutes) were shorter in group 2; there was no difference between the 2 groups in terms of mechanical ventilation time, length of stay in the intensive care unit, and length of hospital stay. There was no decrease in postoperative oxygen parameters and an increase in patient lactate levels with the use of CPB. The use of fresh frozen plasma and platelet suspension in the postoperative period was significantly higher in group 1 (P < .05). The rate of complications and mortality rate were comparable between the 2 groups (P > .05).

CONCLUSIONS

Our study results show that the use of CPB during VAD implantation via left thoracotomy increases operation time and use of blood products, while causing no change in the rate of complications.