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Biomedical subjects

G Debrun

Publications and source records attributed to G Debrun.

At least 73 records · Page 4Linked to original sources
PubMedDate not supplied

High-flow angiopathy: cerebral blood vessel changes in experimental chronic arteriovenous fistula.

Profound vascular damage secondary to high-flow extracranial states has been well characterized. However, changes in cerebral vasculature secondary to high-flow states have not been studied. To determine changes related to high-flow states in cerebral vessels, a rabbit model was developed in which torrential flow was created in the vertebrals, carotids, basilar, and vessels of the circle of Willis by means of a carotid-jugular shunt after ligation of the proximal carotid. The clinical, angiographic, and histologic changes noted in the animal model include: abrupt clinical deterioration after a variable interval with some animals developing ptosis, afferent vessel dilatation and the development of prominent anastomotic channels, variable cerebral vessel histopathology--related to duration and relative proximity to the shunt--affecting all three vessel layers, plump, irregular, and clumped endothelium, denuded with adherent platelets, irregular, duplicated, and thinned internal elastic membrane, frayed with invasion of the intima by mesenchymal cells, vacuolization and necrosis of the media muscle, and invasion of adventitia by foreign cells and small blood vessels. The high-flow angiopathy seen in this model may help explain vascular changes associated with high-flow cerebral vascular lesions, as well as other types of vascular damage.

Animals↗
PubMedDate not supplied

Angiographic follow-up of large cerebral AVMs incompletely embolized with isobutyl-2-cyanoacrylate.

This study evaluated the long-term angiographic results in large cerebral arteriovenous malformations (AVMs) partially embolized with isobutyl-2-cyanoacrylate. Preembolization, immediate postembolization, and long-term follow-up angiograms were performed in 30 large, partially embolized brain AVMs. Particular attention was paid to the relative size of the residual AVM nidus and the embolized arterial feeders, to recruitment of new feeders, to the size of residual draining veins, and to the speed of arteriovenous shunt. Nine cases with less than 50% AVM nidus obliteration showed no significant morphologic changes. In 18 cases with 50-75% obliteration of the AVM nidus, 11 (61.1%) showed no significant changes, six (33.3%) showed enlargement of the AVM nidus, and one (5.5%) evolved to complete angiographic obliteration. In three cases with 75-99% AVM nidus obliteration, one remained unchanged, one showed an increase in the size of the AVM nidus, and one evolved to complete obliteration. Evaluation by plain film, CT, and cerebral angiography of the isobutyl-2-cyanoacrylate deposits showed that when the polymer was positioned predominantly in arterial feeders there was invariably reconstitution of the AVM nidus through leptomeningeal, deep medullary, and/or dural collaterals. This phenomenon did not occur when the isobutyl-2-cyanoacrylate was deposited mainly in the AVM nidus.

Arteriovenous Malformations↗
PubMedDate not supplied

Stenosis of afferent vessels of intracranial arteriovenous malformations.

Four women are described with stenoses of the feeding arteries to cerebral arteriovenous malformations. These stenoses were hemodynamically significant in that the nidus malformations filled late in the arterial phase of angiography and the draining veins did not fill much earlier than the usual venous phase. In two of these patients, who were referred for possible embolization, the stenosis served as an impediment to balloon navigation in the feeding vessel in one and served as a partial contraindication to embolization in the other. It is possible that if these stenoses progress, they may lead to thrombosis of the arteriovenous malformations.

Adult↗
PubMedDate not supplied

Complete myelography with metrizamide.

Thorough myelography of the entire spinal cord including the foramen magnum region can be accomplished consistently and promptly after metrizamide injection via lumbar or lateral cervical puncture. When lumbar puncture is used the patient's torso is oblique, but the neck is prone and straight and the table is tilted 20 degrees head-down to allow direct cervical filling with contrast material. Each region is filmed in several projections, the patient being turned gently from the prone cervical to the supine thoracic position. Of 100 cases without block studied in this way, all had adequate cervical and foramen magnum films. In only five was the contrast material too dilute to show the edges of the spinal cord well and the subarachnoid sac adequately in the thoracic region. In 29 patients, there were mild side effects not requiring medication, while 20 had side effects of a more moderate to severe nature. No seizures were encountered. Metrizamide proved a convenient, efficient, and acceptable contrast medium for myelography when a study of the entire spinal cord is indicated.

Cauda Equina↗
PubMedDate not supplied

Progressive thrombosis of brain arteriovenous malformations after embolization with isobutyl 2-cyanoacrylate.

Embolization of brain arteriovenous malformations (AVMs) with isobutyl 2-cyanoacrylate (IBCA) is an alternative to surgical treatment when dealing with large AVMs with multiple arterial feeders. The deposition of IBCA in the nidus of the AVM may produce an active and progressive thrombosis that may lead to complete occlusion of the nidus and/or to progressive thrombosis of the draining veins. Four clinical examples of progressive thrombosis after IBCA embolization are demonstrated, including two cases in which late follow-up angiography showed complete obliteration of a partly embolized AVM.

Adult↗
PubMedDate not supplied

Preembolization superselective angiography: role in the treatment of brain arteriovenous malformations with isobutyl-2 cyanoacrylate.

Transfemoral and intraoperative embolization of arteriovenous malformations (AVMs) of the brain with isobutyl-2 cyanoacrylate may achieve complete and permanent occlusion of the AVMs. The preembolization superselective angiogram is an important source of information to decrease potential technical or clinical complications while seeking that goal. The information obtained from the angiogram of each individual feeder may be classified as anatomical, dynamic, and functional. This angiogram is performed either through a calibrated-leak balloon glued to a Silastic tubing, which is capable of negotiating cortical arterial curves, or through a short catheter directly placed into a feeder at surgery. In 64 patients, 175 preembolization superselective angiograms were obtained. Of those, 105 were obtained using the transfemoral technique, and 70 were obtained by direct catheterization after a craniotomy. Complications occurred in eight patients with only one permanent injury. Transient neurologic deficit occurred in five patients. One patient developed a permanent left monoplegia and one patient a subarachnoid hemorrhage without permanent neurologic deficit. In one patient, a delayed intracerebral hemorrhage produced a right hemiplegia and aphasia. The patient fully recovered in 6 months.

Bucrylate↗
PubMedDate not supplied

Giant unclippable aneurysms: treatment with detachable balloons.

Nine cases of giant unclippable aneurysms treated with the detachable balloon technique are reported. Adjunctive surgical bypass procedures and arterial ligation were also carried out in four and one cases, respectively. All the patients tolerated occlusion of the carotid artery (eight cases) or of both vertebral arteries (one case). Three patients developed neurologic complications: two transient and one permanent (blindness in one eye). The complications occurred when attempts were made to occlude the aneurysm lumen only to preserve the carotid blood flow. Permanent occlusion of the carotid artery appears safer than aneurysm obliteration. Surgical procedures are necessary if the patient does not tolerate permanent occlusion of the artery or if occlusion of the artery is insufficient to obtain thrombosis of the aneurysm.

Adolescent↗