ABSTRACT
Objective To investigate the feasibility, image quality, and safety of low?tube?voltage, low iodine load iso?osmolar contrast comprehensive cardiac and aortoiliac CT angiography (CTA) for transcatheter aortic valve replacement (TAVR) planning. Methods Ninety?eight consecutive TAVR candidates prospectively underwent combined contrast?enhanced CTA of the aortic root complex and vascular access route. Patients were assigned to group A (2nd generation dual?source CT, 100 kV, contrast 270 mgI/ml iodixanol) or group B (2nd generation dual?source CT, 120 kV, contrast 370 mgI/ml). Mean vascular attenuation, noise, signal?to?noise ratio (SNR), and contrast?to?noise ratio (CNR) of aorta including aortic root, aortic arch, descending aorta at level of diaphragm, abdominal aorta at level of renal artery and femoral artery were compared. Patient creatinine levels before the examination of CTA and during follow?up (24—48 h) were measured. Results The image quality score of aortic root and whole aorta was (4.2±0.7) and (4.3±0.4) respectively in experimental group, (4.3±0.6) and (4.3±0.3) in control group. No significant difference in subjective image quality score between two groups including aortic root image and whole aorta image (t=-0.130,-0.155,P=0.694, 0.822). The image noise of aortic root and femoral artery were higher in experimental group than that in control group (P<0.05). Radiation dose in experimental group was higher than that in control group [(6.1 ± 0.4) vs. (8.0 ± 0.4) mSv, t=-9.253, P=0.001]. There were no significant changes in creatinine levels among groups during the follow?up. Conclusion TAVR candidates can be safely and effectively evaluated by a comprehensive CTA protocol with low iodine load iso?osmolar contrast using low?tube?voltage acquisition.
ABSTRACT
Objective To explore the feasibility and effectiveness of establishing an aortic valve regurgitation canine model by minimally invasive peripheral vascular catheter method. Methods A total of 10 healthy canines were selected in this study. An aortic insufficiency animal model was established by percutaneous femoral artery puncture and aortic dilatation. Aortic angiography and transthoracic echocardiography were used to evaluate aortic valve regurgitation immediately after operation. Results Aortic valve regurgitation animal models were successfully established in all the 10 canines. Two canines died of acute left ventricular failure due to the large aortic regurgitation after the operation. Six surviving canines had moderate aortic regurgitation and two had slight aortic regurgitation; they survived for more than 1 month. Conclusion It is feasible to establish an aortic regurgitation canine model by minimally invasive peripheral vascular catheter method.
ABSTRACT
Objective To explore the feasibility and effectiveness of interventional transcatheter destruction of the aortic valve to establish an animal model with acute aortic valve regurgitation. Methods Eight healthy goats were used for this study. A limited sternotomy approach was used to access the apex of the heart. Puncturing of the apex of the heart was performed to establish a wire track, then, under fluoroscopic guidance a 10 F sheath was inserted along this track of hard wire until to the ascending aorta above the aortic valve. The internal sheath was removed. Via the 10 F sheath a 10 mm occluder of ventricular septal defect (VSD) was introduced into the ascending aorta above the aortic valve. The sheath was pulled back to the left ventricle, while the occluder remained in the ascending aorta above the aortic valve. Then the occluder was quickly pulled back into the left ventricle in order to make some certain damage to the aortic valve. And an acute aortic valve regurgitation model was thus established. Angiography of ascending aorta above the aortic Among the 8 animals, two died of acute left ventricular failure on the spot due to excessive regurgitation blood flow after the operation. Macroscopically, damage of the aortic valve was seen. In the six survivors, angiography of ascending aorta above the aortic valve and Doppler echocardiography showed that moderate degree of regurgitation was detected in 5 and small amount of regurgitation in one. Two experimental goats with moderate degree of regurgitation died of heart failure separately at seven days and fifteen days after the operation. The remaining four experimental goats survived for more than three months. Follow- up checkups with echocardiography suggested the presence of mild- moderate degree of regurgitation. Conclusion Acute aortic valve regurgitation model in experimental goats can be established through transapical transcatheter damage of aortic valve by quickly pulling back a VSD occluder which has been placed in the ascending aorta above the aortic valve. This method is clinically feasible, technically simple and repeatable, the result is reliable, and the degree of regurgitation is controllable.