Neuroprotective adjuncts in thoracic endovascular aortic repair
File(s)
Author(s)
Hanna, Lydia
Type
Thesis
Abstract
Brain injury, in the form of overt stroke and covert stroke affects up to 70% of people undergoing thoracic endovascular aortic repair (TEVAR). While covert stroke remains an under investigated complication from TEVAR, a systematic review, meta-analysis and meta-regression of the literature has demonstrated that the stroke rate has not improved over time.
This body of work aimed to investigate the efficacy of neuroprotective adjuncts against TEVAR related peri-procedural solid and gaseous emboli, to reduce diffusion-weighted magnetic resonance imaging cerebral infarcts (DW-MRI infarcts), cognitive impairment, and stroke.
Flushing TEVAR grafts with CO2 to reduce cerebral air embolisation was associated with a 43% incidence of DW-MRI infarcts. Patients who had fewer or no cerebral infarcts were less likely to experience neurocognitive decline during 6-week follow-up, compared to patients with procedure-related infarcts.
The incidence of DW-MRI infarcts with standard saline flushing of TEVAER grafts was 74% compared to 43% with CO2 flushing (p<0.001). The median total infarct surface area with CO2 flushing was 0mm2 (range, 0-1679) compared to 10mm2 (0-2912) with standard saline flushing (p=0.007). There was no significant difference in the stroke rate (13% saline vs 7% CO2, p=0.196).
Bench-top experiments using mass spectrometry demonstrated that CO2 at 2litres, 4bar pressure for 1 minute provided the optimal ‘flush time’ to de-air the devices.
No difference was observed in the incidence of DW-MRI infarcts patients who underwent TEVAR under cerebral embolic protection ((CEPD) to prevent solid embolisation, compared to controls (71% CEPD vs 65% control, p=0.71). The median total infarct surface area with CEPD was 5mm2 (0-16mm2) versus 15mm2 (0-36mm2) in controls (p=0.42), representing a 67% reduction. At 6-week follow-up, 10% (1/10) CEPD patients experienced less neurocognitive impairment on the composite score compared to 33% (4/12) of control patients (p=0.32).
This body of work aimed to investigate the efficacy of neuroprotective adjuncts against TEVAR related peri-procedural solid and gaseous emboli, to reduce diffusion-weighted magnetic resonance imaging cerebral infarcts (DW-MRI infarcts), cognitive impairment, and stroke.
Flushing TEVAR grafts with CO2 to reduce cerebral air embolisation was associated with a 43% incidence of DW-MRI infarcts. Patients who had fewer or no cerebral infarcts were less likely to experience neurocognitive decline during 6-week follow-up, compared to patients with procedure-related infarcts.
The incidence of DW-MRI infarcts with standard saline flushing of TEVAER grafts was 74% compared to 43% with CO2 flushing (p<0.001). The median total infarct surface area with CO2 flushing was 0mm2 (range, 0-1679) compared to 10mm2 (0-2912) with standard saline flushing (p=0.007). There was no significant difference in the stroke rate (13% saline vs 7% CO2, p=0.196).
Bench-top experiments using mass spectrometry demonstrated that CO2 at 2litres, 4bar pressure for 1 minute provided the optimal ‘flush time’ to de-air the devices.
No difference was observed in the incidence of DW-MRI infarcts patients who underwent TEVAR under cerebral embolic protection ((CEPD) to prevent solid embolisation, compared to controls (71% CEPD vs 65% control, p=0.71). The median total infarct surface area with CEPD was 5mm2 (0-16mm2) versus 15mm2 (0-36mm2) in controls (p=0.42), representing a 67% reduction. At 6-week follow-up, 10% (1/10) CEPD patients experienced less neurocognitive impairment on the composite score compared to 33% (4/12) of control patients (p=0.32).
Version
Open Access
Date Issued
2022-10
Date Awarded
2024-12
Copyright Statement
Creative Commons Attribution NonCommercial Licence
License URL
Advisor
Gibbs, Richard
Bicknell, Colin
Hamady, Mohamad
Publisher Department
Department of Surgery and Cancer
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)