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Trial Lecture – time and place
See Trial Lecture.
Adjudication committee
- First opponent: Associate Professor Joris Jaspers, University Medical Center Utrecht, Netherlands
- Second opponent: Professor Nils Kristian Skjærvold, NTNU: Norwegian University of Science and Technology, Norway
- Third member and chair of the evaluation committee: Professor II Signe Søvik, University of Oslo
Chair of the Defence
Associate Professor John-Peder Escobar Kvitting, University of Oslo
Principal Supervisor
Professor II Per Steinar Halvorsen, University of Oslo
Summary
Severe heart failure can be treated with an implantable left ventricular assist device (LVAD) when heart transplantation is not possible. It is a blood pump comprised of an inflow cannula into the left ventricle, a housing for an impeller, an outflow graft to the aorta, and a driveline (lead) that exits the body.
Devastating complications like stroke and multiorgan failure may follow from pump thrombosis (PT), classified as ‘prepump’ if at the inflow cannula or ‘intrapump’ if at the volute or impeller. Early and localized detection of PT is crucial to ensure good treatment outcomes through timely interventions. However, the only continuous clinical detection method today, based on pump power, is known to have limitations.
Prepump thrombosis is diagnosed today mainly in near-fully obstructive and acute cases, while gradual cases often go unnoticed. Previous research at Rikshospitalet has shown that vibration measurements by a pump-attached accelerometer can provide early indications of intrapump thrombosis. In this thesis, we therefore asked:
Q1) Can pump vibrations also reveal gradual prepump thrombosis? Q2) Can external driveline vibrations reflect PT indications made from pump vibrations?
To answer Q1, obstructions were first simulated by a mock circuit and balloons within the inflow cannula. Then, we did porcine model experiments to confirm the initial findings with more realism, but also to answer Q2 after having induced actual thrombosis.
To conclude, LVAD vibrations can give reliable indications of gradual prepump thrombosis, much better than pump power measurements. Such vibrations had different characteristics from those of intrapump thrombosis, which can be used for PT localization. Also, the vibrations on the driveline largely reflected the pump vibrations indicative of PT. That opens a retrofit monitoring solution for existing patients.
Additional information
Contact the research support staff.