Interactive cardiovascular and thoracic surgery
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Interact Cardiovasc Thorac Surg · Jun 2010
Physical stress testing of bovine jugular veins using magnetic resonance imaging, echocardiography and electrical velocimetry.
Bovine jugular veins (BJVs) (Contegra) are valve-bearing pulmonary artery substitutes. Their valves have higher profiles than human pulmonary valves; this might result in less optimal performance. Therefore, we investigated the impact of stress and undersizing on conduit performance with ergometry, echocardiography and magnetic resonance imaging (MRI). ⋯ Data was evaluated as follows: comparison of stress related maximal individual valve performance changes (magnetic resonance: exercise induced average stroke volume changes by 61+/-49%; mean insufficiency increased by 2% in patients with <1% rest insufficiency and by 8% after rest insufficiency of >10%; the average rest gradient of 24+/-11 mmHg rose to 40+/-20 mmHg), and stratification of pooled observations by regurgitation fraction, insufficiency grades and z-values (insufficiency rose with increasing heart rate and decreasing stroke volume; undersizing increased gradients during recovery by 7+/-0.7 mmHg/z-value). Contegras high-profile valves tolerate stress without performance drop. Stress induced changes of insufficiency and gradient were clinically not significant, but sufficient to distort examination results; therefore, constant examination conditions are indispensable for a correct follow-up.
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Interact Cardiovasc Thorac Surg · Jun 2010
Spinal cord protection with selective spinal perfusion during descending thoracic and thoracoabdominal aortic surgery.
Open repair of aortic aneurysm causes spinal cord perfusion pressure to decrease due to the steal phenomenon from the bleeding of intercostal arteries and cross-clamping of the aorta. We attempted to perfuse the intercostal arteries for preoperative detection of the artery of Adamkiewicz using newly developed catheters. Fifteen patients underwent selective spinal perfusion with our original catheter as spinal protection during the procedure of distal descending thoracic aneurysm (DTA) or thoracoabdominal aortic aneurysm (TAAA) repair. ⋯ MEPs were still observable after graft replacement in all patients and there were no cases of paraparesis/paraplegia. All patients were discharged ambulatory. Selective spinal perfusion maintains the quantity of total blood flow in the spinal cord and is very useful for reducing the incidence of ischemic injury of the spinal cord during operation.