Introduction
Left ventricular assist device (LVAD) therapy confers both a survival and quality of life benefit for advanced heart failure patients.1 LVADs have standardly been implanted via full median sternotomy,2 but the smaller size of newer centrifugal pumps has facilitated the use of less invasive, sternal-sparing techniques, either via bilateral thoracotomies or upper hemi-sternotomy with left thoracotomy.3–5Non-sternotomy LVAD implantation techniques have been shown to be safe and effective when both HeartwareTMHVADTM (Medtronic, Minneapolis, MN)6,7 and Heartmate 3TM (HM3) (Abbott, Chicago, IL)8,9 devices are used, and they have demonstrated lower rates of right ventricular failure, blood product transfusions, and lengths of hospital stay by comparison.
Several advantages of sternal-sparing approaches compared to sternotomy have been proposed. There may be less risk of right heart failure, a common complication after LVAD implantation,10 because the pericardium over the right ventricle is preserved.8 With the heart maintained in anatomic position, there is less potential for pulmonary artery obstruction and coronary hypoperfusion.8 Additionally, better visualization of the apical inflow anastomosis and assessment of hemostasis are afforded, and the sternum is spared for more easy sternal entry if the patient is to move forward with heart transplantation following LVAD implant. Finally, without sternal restrictions, patients can begin more prompt physical therapy after surgery, which is beneficial for rehabilitation in both bridge-to-transplant and destination therapy patients.8
In addition to improvements in newer LVAD generations and development of new implantation techniques, inflow cannula angulation has also been tied to patient outcomes. In HVAD patients, Imamura et al.associated smaller cannula coronal angles with improved left ventricular unloading,11 leading to improved myocardial structural and functional parameters that help prevent heart failure recurrence.12 Furthermore, angles ≤65° were associated with reduced heart failure readmission rates.11 Prior work has also suggested that inflow cannula angles after LVAD implantation can be more consistently reproduced with a sternal-sparing approach, compared to median sternotomy.13
Increasing adoption of sternal-sparing approaches to LVAD implantation underscores the need for individual institutions to illustrate their experience and patient outcomes using these techniques. The purpose of this study is to compare both inflow cannula angles and postoperative outcomes for patients who received LVAD implantation by either median sternotomy or bi-thoracotomy (BT).