CENTRIFUGAL-FLOW LVAD INFLOW CANNULA POSITION: PREOPERATIVE INFLUENCES
AND POSTOPERATIVE OUTCOMES
Background: We previously demonstrated better inflow cannula (IFC)
position and reduced pump thrombosis with a centrifugal-flow LVAD
(CF-LVAD) compared to an axial-flow device. We hypothesized that implant
technique and patient anatomy would affect CF-LVAD IFC positioning and
that malposition would impact LV unloading and outcomes. Methods: Pre-
and postoperative computed tomography (CT) scans were reviewed for
patients with six-month follow-up. Malposition was quantified using
angular deviation from an ideal line in two planes. IFC position was
compared between conventional sternotomy (CS) and lateral
thoracotomy-hemisternotomy (LTHS). The influence of LV end-diastolic
dimension (LVEDD), body mass index (BMI), and CT-derived anatomy was
determined. LV unloading was assessed by LVAD flow index (FI) and pre-
to post-LVAD decrement in mitral regurgitation (MR) and LVEDD. Outcome
measures were pump thrombus or stroke (PT/eCVA); 30-day and total heart
failure-related readmissions (HFRAs); and survival free of surgery for
LVAD dysfunction. Results: One hundred fourteen patients met criteria.
Total malposition magnitude was higher for CS than LTHS (p=0.04).
Midline-LV apex distance predicted lateral-plane malposition (p=0.04),
while apex-LVOT angle predicted both anterior- (p=0.01) and
lateral-plane (p=0.04) malposition. Lateral-plane malposition predicted
decreased LVAD FI at three (p=0.03) and six (p=0.01) months. Total
malposition magnitude predicted increased 30-day HFRAs (p=0.04), while
lateral-plane malposition predicted more overall HFRAs (p=0.01).
Malposition was not associated with PT/eCVA, changes in MR or LVEDD, or
survival free of surgical revision. Conclusions: Patient anatomy and
surgical technique were associated with CF-LVAD IFC malposition. In
turn, malposition was associated with increased readmissions and
decreased LVAD FI.