A Quantitative Assessment of Left Ventricular Assist Device Inflow Cannula Position with Contrast Enhanced Gated Cardiac Multislice Computed Tomography and Its Clinical Correlation

Abstract

<h3>Purpose</h3> Inflow cannula malposition (ICM) is a major concern in Left Ventricular Assist Device patients (LVAD).We propose a quantitative classification of IC position by cardiac Computed Tomography (CCT) to assist in the diagnosis of IC malposition. <h3>Methods and Materials</h3> In 16 consecutive LVADs-Pts (14 Heart-Mate II) underwent 64 slices CCT. IC position was measured during mid diastole by: 1) acute angle between the long axis of the IC and the long axis of the left heart perpendicular to the mitral annulus plane and 2) distance between the IC tip and the opposing LV wall. The IC position was deemed: 1) Appropriate: if angle is < 30° and the distance > 1cm. 2) Intermediate: if angle is between 31-60° and the distance > 1cm. 3) Malposition: if angle is >60° or the distance <1cm. CT measurement and the clinical presentation were determined independently by a cardiac CT cardiologist and a LVAD/transplant cardiologist respectively. <h3>Results</h3> The mean age was 55±14 yrs, 50 % male and 60% had ischemic cardiomyopathy. Pts were divided into 2 groups according to the clinical presentation. Group 1 were 6 pts with suspected IC malposition (frequent LVAD alarm, low output, recurrent VT, and hemolysis ) and group 2 were 10 pts with non IC related indication (source of emboli/infection, effusion/hematoma, and 2 LV function/aortic valve assessment). Group 1 had higher LVAD-LV angle and shorter LVAD-LV distance as compared to Group 2 (63±6° vs 35 ± 12 ° p=0.001, 0.6±0.5 cm vs 3.5±2.3 cm P=0.02). All pts with clinically suspected ICM were deemed to have ICM as determined by CCT. [figure 1] <h3>Conclusions</h3> ICM can be detected by quantitative measurements in CCT, further studies are needed.