Aims and objectives
Mechanical circulatory support therapy improved continuously over the last years with survival outcomes that are comparable nowadays to cardiac transplantation [1].
However long-term adverse events,
particularly thromboembolic complications still pose a challenge for this therapy [2].
Since left ventricular assist devices (LVAD) change the natural intraventricular flow patterns any malposition of the LVAD may lead to unfavorable flow stagnation areas and thrombus development leading to thrombosis or strokes [3–7] (see Fig.
1).
In this retrospective study the correlation between pump thrombosis and pump position was...
Methods and materials
Routinely acquired X-rays and CT-scans of 74 patients implanted with a HVAD pump (Medtronic plc,
Dublin,
Ireland) between 2012 and 2015 were retrospectively analyzed (see Fig.
2).
A study group with existing pump thrombosis (PT,
n=8) and a control group (NT,
n=10) were identified.
The inflow cannula (IC) position of the LVAD was measured using the X-Ray and CT-scans as follows.
In the CT-scans multiplanar reconstructions (see Fig.
3) were used to get the three-chamber view defined by the following anatomical landmarks: the mitral valve,...
Results
Demographics of the pump thrombosis group (n=8) and the selected control group (n=10) did not differ significantly from the whole patient populations (PT group age: 60.4±8.5y,
Male n=7/8,
BMI: 26.1±4.2 kg/m²,
NT group age: 59.5±12.9y,
Male n=8/10,
BMI: 25.5±3.6 kg/m²,
whole population age: 59.9±10.8y,
Male n=3/18,
BMI: 25.7±3.8 kg/m²).
The angleα (as defined in Fig 3) was different in the PT group compared to NT patients (PT ‑22.0±4.7° vs.
NT ‑1.2±7.5°; p= 0.006).
For the angleβ differences were found,
albeit without statistical significance (PT -9.3±15.1°...
Conclusion
This study confirms the importance of appropriate intraventricular pump position.
Pump position parameters associated to pump thrombosis were retrospectively identified from X-Ray and CT images (Fig.
6).
Pumps not directly facing towards the mitral valve seem to be more prone to pump thrombosis probably because of disturbed inflow conditions.
A significant correlation of parameters from X-Ray and 3-dimensional CT reconstruction was found,
therefore indicating that routine X-Ray images might be used to evaluate pump malposition and increased risk of pump thrombosis.
Personal information
Assoc.Prof.
Dipl.-Ing.
Francesco Moscato,
PhD
Center for Medical Physics and Biomedical Engineering,
Medical University of Vienna,
Austria
Ludwig Boltzmann Cluster for Cardiovascular Research
Währinger Gürtel 18,
AKH-4L
A-1090 Vienna,
Austria
Tel: +431 40400 - 27270
e-mail:
[email protected]
References
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Theochari et al.,
“Heart transplantation versus left ventricular assist devices as destination therapy or bridge to transplantation for 1-year mortality: a systematic review and meta-analysis,” Ann Cardiothorac Surg,
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no.
1,
pp.
3–11,
Jan.
2018.
[2] J.
K.
Kirklin et al.,
“First Annual IMACS Report: A global International Society for Heart and Lung Transplantation Registry for Mechanical Circulatory Support,” The Journal of Heart and Lung Transplantation,
vol.
35,
no.
4,
pp.
407–412,
Apr.
2016.
[3] K.
Ghafourian et al.,
“Assessment of...