Left ventricular assist device implantation with left lateral thoracotomy with anastomosis to the descending aorta

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.

Left Ventricular Assist Device as a Destination Therapy: Current Situation and the Importance of Patient Selection

Advanced heart failure is a growing problem for which the best treatment is cardiac transplantation. However, the shortage of donors' hearts made left ventricular assist devices as destination therapy (DT-LVAD) a highly recommended alternative: they improved mid-term prognosis as well as patients' quality of life. Current intracorporeal pumps with a centrifugal continuous flow evolved in the last few years. Since 2003, when first LVAD was approved for long-term support, smaller device sizes with better survival and hemocompatibility profile were reached. The most important difficulty lies in the moment of the implant. Recent indications range from INTERMACS class 2 to 4, with close monitoring in intermediate cases. Moreover, a large multiparametric study is needed for considering the candidacy: basal situation, with a special interest in frailty, comorbidities, including renal and hepatic dysfunction, and medical background, considering every prior cardiac condition, must be evaluated. In addition, some clinical risk scores can be helpful to measure the possibility of right heart failure or morbi-mortality. With this review, we sought to summarize all the device improvements, with their updated clinical results, as well as to focus on all the patient selection criteria.

Lateral thoracotomy versus sternotomy for left ventricular assist device implantation

PURPOSE OF REVIEW

Traditionally, left ventricular assist devices (LVADs) are implanted via the standard median sternotomy approach. However, a left thoracotomy approach has been purported to offer physiologic benefits. As a result, utilization of the left thoracotomy for LVAD placement is increasing globally, but the benefits of this approach versus sternotomy are still evolving and debatable. This review compares the median sternotomy and thoracotomy approaches for LVAD placement.

RECENT FINDINGS

Recent meta-analyses of LVAD implantation via thoracotomy approach suggest that the thoracotomy approach was associated with a reduced incidence of RVF, bleeding, hospital length of stay (LOS), and mortality [1 ▪▪ ,2 ▪▪ ] . No difference in stroke rates was noted. These results offer support as to the feasibility of a thoracotomy approach for LVAD implantation but also highlight its potential superiority over sternotomy.

SUMMARY

The most recent literature supports the use of lateral thoracotomy for placement of left ventricle assist devices compared to median sternotomy. Long-term outcomes from lateral thoracotomy are still unknown, however, short-term results favor lateral thoracotomy approaches for LVAD implantation. While the conventional median sternotomy approach was the original operative technique of choice for LVAD implantation, lateral thoracotomy is quickly emerging as a potentially superior technique.

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.

Long-term Outcomes in Ventricular Assist Device Outflow Cannula Anastomosis to the Descending Aorta

BACKGROUND

Left ventricular assist device (LVAD) implantation via thoracotomy with outflow cannula anastomosis to the descending aorta is an alternative implantation technique that uses a single incision and avoids anterior mediastinal planes. We evaluated long-term survival and hospital readmissions following LVAD implantation via thoracotomy with outflow cannula anastomosis to the descending aorta.

METHODS

Adult patients implanted with a continuous flow centrifugal LVAD at an academic center were retrospectively analyzed. Patients were assigned to one of the two cohorts based on the anastomosis site of the LVAD outflow cannula: ascending aorta cohort (Asc-Ao) and descending aorta cohort (Desc-Ao). Primary and secondary outcomes were survival and hospital readmissions during device support. Readmission analysis included patients with ≥30-day survival following discharge. Multivariable analysis and propensity score matching were performed.

RESULTS

Survival analysis included 330 patients (Asc-Ao: 272, Desc-Ao: 58). Readmission analysis included 277 patients (Asc-Ao: 231, Desc-Ao: 46) and a total of 1028 readmissions during 654 patient-years of follow-up were analyzed. There was no significant difference in in-hospital, 6-month, 1-year, 3-year and 5-year mortality between the two cohorts. Readmission-free survival, 30-day readmission, number of admissions per year and hospital length of stay per year were not significantly different between the 2 cohorts following adjustment for patient characteristics.

CONCLUSIONS

This study found no difference in long-term survival or hospital readmissions between LVAD implantation via thoracotomy with outflow cannula anastomosis to the descending aorta and standard implantation.

Exercise capacity following ventricular assist device implantation via thoracotomy with outflow cannula anastomosis to the descending aorta

Left ventricular assist device (LVAD) implantation via left lateral thoracotomy with outflow cannula anastomosis to the descending aorta is an alternative technique that avoids anterior mediastinal planes and requires a single incision. This study compares changes in exercise capacity following LVAD implantation with outflow cannula anastomosis to the descending aorta versus ascending aorta. Adult patients who received a continuous flow centrifugal LVAD implantation and completed both pre- and postimplantation cardiopulmonary exercise tests (CPETs) and or 6-minute walk tests (6MWT) were included. Change in CPET parameters (maximum oxygen intake: vO₂ max, oxygen uptake efficiency ratio: OUES, ventilatory efficiency ratio: vE/vCO₂ Slope) and 6MWT distance were compared between ascending and descending aorta anastomosis groups. Ascending and descending aorta anastomosis cohorts included 59 and 14 patients, respectively. Pre- and postimplantation CPETs were performed 63 ± 12 days before and 216 ± 17 days following implantation. The improvement in CPET parameters (vO₂ max, OUES, vE/vCO₂ Slope) or 6MWT distance was not significantly different between the ascending and descending aorta anastomosis groups. This study found no significant difference in the improvement of CPET parameters or 6MWT distance between LVAD implantation via thoracotomy with outflow cannula anastomosis to descending aorta and standard implantation via sternotomy with outflow cannula anastomosis to ascending aorta.

Does minimally invasive approach reduce risk of infection after ventricular assist device implantation?

BACKGROUND

We analyzed patients with left ventricular assist device (LVAD) related and specific infection, and aimed to determine whether surgical technique implantation affect the frequency of infection.

METHODS

We retrospectively analyzed the data of 99 patients who received LVAD at our department between June 2013 and June 2019. Patients were divided into two groups according to the surgical technique. Group A (n = 58) was conventional sternotomy (CS) and group B (n = 41) was on-pump minimally invasive left thoracotomy (MILT). Demographics, preoperative risk factors, LVAD infections, surgical incision site, driveline site, and outcomes were compared between these two groups.

RESULTS

Mean follow up time was 589 ± 480 (31-2171) days. Infection was detected in 34% (41/99) of LVAD patients. Admission to emergency department and intensive care unit (ICU) in last 6 months were significantly higher in MILT group. There was no difference between the two groups in terms of driveline exit site infection (CS: 28%, MILT: 27%) (p > 0.05). Seven (17%) patients had infection in the thoracotomy incision site area in the MILT group. The rate of ICU hospitalization in the last 6 months was seen as the only independent risk factor increasing the frequency of infection (R = 0.30; p = 0.016). Survival analysis at 60 days, 1 year and 2 years showed no difference between the two groups (p = 0.09).

CONCLUSIONS

Despite advances in pump technology and surgical technique, infection is still an important cause of mortality and morbidity.

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.

Conventional and alternative sites for left ventricular assist device inflow and outflow cannula placement

Left ventricular assist device (LVAD) therapy is a well accepted and effective strategy to treat advanced heart failure. The miniaturized third-generation centrifugal pumps HeartWare HVAD (Medtronic, Dublin, Ireland) and HeartMate 3 (Abbott, Illinois, USA) are the two most commonly implanted systems in the contemporary era. Their design has allowed clinicians to pioneer several alternate and less invasive implantation techniques to tackle a broad spectrum of clinical scenarios. A brief review and discussion of alternative surgical techniques for both inflow and outflow cannula insertion, in the contemporary LVAD surgery era, are herein reported.

Durable Continuous-Flow Mechanical Circulatory Support: State of the Art

Implantable mechanical circulatory support (MCS) systems for ventricular assist device (VAD) therapy have emerged as an important strategy due to a shortage of donor organs for heart transplantation. A growing number of patients are receiving permanent assist devices, while fewer are undergoing heart transplantation (Htx). Continuous-flow (CF) pumps, as devices that can be permanently implanted, show promise for the treatment of both young and old patients with heart failure (HF). Further improvement of these devices will decrease adverse events, enable pulse modulation of continuous blood flow, and improve automatic remote monitoring. Ease of use for patients could also be improved. We herein report on the current state of the art regarding implantable CF pumps for use as MCS systems in the treatment of advanced refractory HF.

Left Ventricular Assist Device Implantation via Dual Left Thoracotomy in an Adult Patient with Congenitally Corrected Transposition of the Great Arteries

A 59-year-old man presented for possible durable ventricular assist device (VAD) implantation. He had previously been diagnosed with congenitally corrected transposition of the great arteries, a ventricular septal defect, an atrial septal defect, pulmonary valve stenosis, and aortic valve regurgitation. In the previous 22 years, he had undergone palliative cardiac surgery 3 times. VAD implantation as a bridge to transplantation was planned. Owing to severe adhesions, mesocardia, a left ascending aorta, and moderate aortic regurgitation, we performed VAD implantation and aortic valve closure via a dual left thoracotomy and partial sternotomy.

Bridge to Transplantation With Long-Term Mechanical Assist Devices in Adults With Transposition of the Great Arteries

Prior to the widespread adoption of the arterial switch operation, patients with transposition of the great arteries (TGA) commonly underwent atrial switch operation (Mustard or Senning). It is not uncommon for these patients to progress to end stage heart failure and increasingly ventricular assist devices (VADs) are used to support these patients as a bridge to transplantation, though there is limited experience with this worldwide. A retrospective review of our institution's VAD database was undertaken and revealed seven adult patients with a history of TGA and subsequent systemic ventricular failure were implanted with a VAD: four of whom received the VAD as a bridge to transplantation (BTT) at the time of implantation, two who were initially designated as destination therapy secondary to severe pulmonary hypertension, and one who was designated as destination therapy secondary to a high risk of life-threatening non-compliance. Seven patient cases who received a VAD for severe systemic ventricular failure were included in this study. The mean age of the patients was 40 years and the majority of patients were male (6/7, 85%). Five of the patients (71.4%) had previously undergone an atrial switch operation and all of these were Mustard procedures. Two of the seven patients (28.5%) had congenitally corrected transposition of the great arteries (CC-TGA). Two of the seven patients (28.5%) had supra-systemic pulmonary pressures before VAD implantation and were designated as destination therapy (DT). One of these patients was later designated as BTT as an improvement in his pulmonary vascular resistance was observed, and subsequently underwent heart transplantation. Because of anatomic considerations, four of the patients (57%) underwent redo-sternotomy with outflow cannula anastomosis to the ascending aorta, one patient underwent VAD implantation via a left subcostal incision with anastomosis of the outflow graft to the descending thoracic aorta, and two patients (28.5%) underwent VAD implantation via a left thoracotomy and anastomosis of the outflow cannula to the descending thoracic aorta. Six of the seven patients had a HeartWare HVAD VAD implanted; one received a Thoratec Heartmate II VAD. Two patients underwent VAD explant and orthotopic heart transplant, 222 days and 444 days after VAD implant, respectively. One patient died on postoperative day 17 after complications from recurrent VAD thrombosis despite multiple pump exchanges. Four patients remain on VAD support, three of these patients are awaiting transplantation at last follow-up (mean days on support, 513 days). Bridge to transplantation with a durable VAD is technically feasible and relatively safe in patients with TGA. Multiple redo-sternotomies can be avoided with a left posterior thoracotomy approach and outflow graft anastomosis to the descending thoracic aorta after careful anatomic considerations.