Changes in carotid flow velocity induced by direct percutaneous carotid angiography in man

Direct percutaneous carotid artery stenting with distal protection: technical case report

We describe the technique of percutaneous carotid artery stent placement with distal protection in a patient in whom marked innominate artery ectasia prevented transfemoral access to the right common carotid artery. After induction of general anesthesia, ultrasound was used to guide direct puncture of the common carotid artery followed by the introduction of a 5 French sheath. A GuardWire distal protection balloon (Medtronic, Santa Rosa, CA) was placed distal to the lesion and deployed at nominal diameter. A balloon-expandable stent was deployed without difficulty. Following stent placement, angiography demonstrated improved flow in the entire right carotid artery territory. There were no complications related to cervical soft tissue damage or clinical embolism. The patient tolerated the procedure well and was discharged in 24 hours. Direct carotid access is acceptable in select patients in whom a transfemoral, brachial, or transradial approach is technically difficult. The use of distal cerebral protection devices may reduce cerebral embolism associated with these procedures.

Doppler-sonographic examination of the arterial flow in the carotid and supratrochlear arteries during carotid angiography

In 55 patients, the blood flow in the carotid and supratrochlear arteries was examined by Doppler sonography during cerebral angiography. In general, a threefold response was observed: an initial phase of turbulence during the injection was followed by a phase of depressed and then of increased arterial flow. The second phase of reduced perfusion which probably is caused by the increased viscosity of the mixture of contrast medium and blood, is more pronounced in the internal carotid artery, whereas the third phase of accelerated flow is more marked in the external carotid artery. In patients with an occlusion of the internal carotid artery, the cerebral blood supply often depends on the collateral pathway via the ophthalmic artery. In these cases, the reduction of the blood flow is specially marked and long-lasting, as we could show. This may contribute to a higher angiographic risk of those cases with an important ophthalmic collateral flow.

A qualitative comparison of two contrast media for cerebral angiography. A clinical method

A qualitative comparison of two contrast media for cerebral angiography with regard to contrast should, preferably, be based on a comparison made in two different hemispheres of one patient. Two problems then arise which made evaluation difficult. Vasodilation occurs after the first contrast injection as a result of which the second contrast medium to be compared flows into a dilated vascular tree. In addition, in the case of a comparison in two different hemispheres, variations of image geometry occur, resulting in differences of sharpness and contrast. The method of solving these problems is discussed and is illustrated by a comparison of two contrast media which might be expected to produce differences in contrast because of their physical properties. The results of this clinical comparison show that the expected differences can be partly demonstrated.

Reliability of Doppler sonography in extracranial cerebro-vascular stenosis

Of our patients who underwent quantitative Doppler sonography (Haemato-Tacho-Graphy), 382 underwent carotid angiography and 61 vertebral artery angiography. The reliability of the method proved to be between 90 and 95 percent for carotid as well as for vertebral arteries. The HTG proved to be a useful addition to angiography in patients with extracranial cerebro-vascular stenosis.

Changes in carotid flow velocity induced by lowering cerebrospinal fluid pressure in normal pressure hydrocephalus

This is a report of changes in blood flow velocity in the carotid system induced by lumbar puncture in five patients who had clinical and neuroradiological signs of normal pressure hydrocephalus. After lowering cerebrospinal fluid pressure an increase of carotid flow velocity was found on Doppler hematotachography. These changes of carotid blood flow velocity could not be demonstrated in a control group of four patients with normal cerebrospinal fluid dynamics. This method is easy to perform, does not overtax the patient and seems to be indicated for the diagnosis of NPH. It is presented as a new, simple, reproducible aid to the diagnosis of NPH by Doppler hematotachography.

Changes in carotid flow velocity during catheterization of the aortic arch and common carotid artery

Quantitative percutaneous flow velocity measurements are possible in carotid arteries by means of a directional Doppler flow velocity device and registration on a polygraph. Carotid flow velocity changes were recorded during catheterization of the ascending aorta and common carotid artery and after infusion of 20 cc contrast medium in the ascending aorta. The results indicate an increase in the flow velocity in the right common carotid artery after infusion of the contrast medium in the ascending aorta, which is thought to be attributed to a diffuse vasodilatation, at least in the cerebral circulation. The catheterization of the ascending aorta and common carotid artery seems to interfere with the common carotid flow velocity.