Thermal Changes during Rheolytic Mechanical Thrombectomy.
OBJECTIVE
To characterize thermal changes induced by rheolytic thrombectomy (RT) within an ex vivo venous model and evaluate resultant changes of endothelial and vessel wall injury.


METHODS
Patent human saphenous vein segments without thrombus were mounted in an ex vivo perfusion system with a temperature probe apposed to the adventitial surface. RT was performed over a guide wire to facilitate device centering. Continuous RT was performed for 4 minutes with temperature recorded every 10 seconds. Pulsed RT was performed for eight cycles of 30 seconds followed by 10 seconds of deactivation. Mean temperature increase, maximum temperature (Tmax), intimal/medial thickness, endothelial cell staining (CD31), and heat shock protein 90 (HSP90) expression were compared between untreated and RT-treated venous segments.


RESULTS
Continuous RT produced a mean 7.6°C increase in temperature above baseline with mean Tmax of 44.1°C. Pulsed RT produced a mean 7.3°C increase in temperature and mean Tmax of 43.8°C. Differences in mean temperature increase (P = .66) and Tmax (P = .71) between the two groups were not statistically significant. RT-treated segments showed intima/media thinning (0.32 mm before RT and 0.18 mm after RT; P = .004) and reduction in intact endothelium (38.8% before RT and 13.8% after RT; P = .002). Staining for HSP90 showed a 3.1% increase in expression after RT (P = .31).


CONCLUSIONS
RT in this venous model showed reproducible increases in vessel temperature and evidence of endothelial and vessel wall injury. Avoiding prolonged RT application to a focal vascular segment during clinical use may be beneficial.
Section of Interventional Radiology, Department of Radiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania; Penn Image Guided Interventions Laboratory, G.J.N.), Philadelphia Veterans Affairs Medical Center, Philadelphia, Pennsylvania.
Michael C
MC
Hsu
Section of Interventional Radiology, Department of Radiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania; Penn Image Guided Interventions Laboratory, G.J.N.), Philadelphia Veterans Affairs Medical Center, Philadelphia, Pennsylvania.
Charles N
CN
Weber
Penn Image Guided Interventions Laboratory, G.J.N.), Philadelphia Veterans Affairs Medical Center, Philadelphia, Pennsylvania.
Mustafa A
MA
Mohammed
Section of Interventional Radiology, Department of Radiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania; Penn Image Guided Interventions Laboratory, G.J.N.), Philadelphia Veterans Affairs Medical Center, Philadelphia, Pennsylvania.
Terence P
TP
Gade
Section of Interventional Radiology, Department of Radiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania; Penn Image Guided Interventions Laboratory, G.J.N.), Philadelphia Veterans Affairs Medical Center, Philadelphia, Pennsylvania.
Stephen
S
Hunt
Section of Interventional Radiology, Department of Radiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania.
Gregory J
GJ
Nadolski
Section of Interventional Radiology, Department of Radiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania. Electronic address: timothy.clark@uphs.upenn.edu.
Timothy W I
TW
Clark
D004730:Endothelium, Vascular / Q000293:injuries / Q000378:metabolism / Q000473:pathology / Q000601:surgery*; D018841:HSP90 Heat-Shock Proteins / Q000378:metabolism; D006801:Humans; D066298:In Vitro Techniques; D010477:Perfusion; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000378:metabolism; D012501:Saphenous Vein / Q000293:injuries / Q000378:metabolism / Q000473:pathology / Q000601:surgery*; D013696:Temperature; D017131:Thrombectomy / Q000009:adverse effects / Q000379:methods*; D013997:Time Factors; D057772:Vascular System Injuries / Q000209:etiology / Q000378:metabolism / Q000473:pathology
D018841:HSP90 Heat-Shock Proteins; D019408:Platelet Endothelial Cell Adhesion Molecule-1