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Biomedical subjects

B George

Publications and source records attributed to B George.

At least 181 records · Page 10Linked to original sources
PubMed1989

Vascular abnormalities in the neck associated with intracranial aneurysms.

In 102 cases of ruptured intracranial aneurysms, the cervical as well as the cranial areas were explored by angiography. Loops in the course of the cervical vessels were present in 28 patients; features of fibromuscular dysplasia were present in 31 patients; and in 50 patients, no abnormalities were observed. In 7 patients, both cervical anomalies were present. Loops were associated with single aneurysms (95%), located primarily on the anterior communicating artery (76%), predominantly in men (M/F = 1.6). Aneurysms with fibromuscular dysplasia affected women more than men (F/M = 7), were frequently multiple (58%), and were located mainly on the intracranial part of the internal carotid and vertebral arteries (51%). These data suggest new concepts of aneurysm formation from inherited diseases and should permit the detection of some aneurysms before rupture.

Adolescent↗
PubMed1989

[Clinical tolerance of CY 216 (Fraxiparin) in the prevention of thromboembolic accidents after neurosurgery].

Clinical tolerance of CY 216 was assessed on 97 patients in two neurosurgical departments (Hopital Lariboisière and Hopital Beaujon, Paris). All the 97 patients were operated on by different cranial approaches, but always including bone flap. No thrombo-embolic event could be detected in this series. Post-operative intracranial hemorrhage was observed in 19 cases on the basis of CT scan performed on the first and seventh post-operative day. Among these 19 patients, 8 presented an increase of the hemorrhagic aspect between the 2 CT scan. However, clinical state of these patients improved and no reoperation was necessary to treat these hemorrhages. From this study, we consider that CY 216 is an effective mean of thrombo-embolism prevention with little hemorrhagic side-effect. Therefore, it can be recommended in the aftermath of intracranial surgical procedures.

Adolescent↗
PubMed1989

[Lateral and lateral anterior approaches in tumors of the cervical vertebrae].

The limit of the standard anterior and posterior approaches on the cervical spine is a small area including the pedicle and transversary process. However, this area contains the vertebral artery and the merging cervical roots. The lateral-anterior route gives access to both structures while the lateral one leads mainly to the intervertebral foramen and nerve roots. Both techniques are described with stress on the great advantages of the lateral-anterior route: easy exposure, large operative field, possibility of complementary arthrodesis and venous graft by-pass on the vertebral artery. Experience on 14 cervical bony tumors resected through the lateral-anterior approach is reported. Complementary techniques were performed in 5 cases: carotid-vertebral artery by-pass in 1, laminectomy in 2 and bone grafting in 2. Therefore, the lateral anterior approach is considered a good way to deal with the intermediate part of the cervical spine.

Adolescent↗
PubMed1989

[Materials for osteo-dural reconstruction in the cranium. An update].

Materials available for repair of a bony or dural defect at the cranial level are reviewed with particular attention stressed on their qualities and drawbacks for neurosurgical purposes. These materials include autologous or heterologous bone graft and biologically stable or biodegradable implants. No material can demonstrate ideal qualities of biocompatibility and biofunctionality. It should be either perfectly stable biologically and inert or perfectly biodegradable allowing simultaneous new bone reconstruction; moreover, it should be sterilizable, disposable, easy to handle and of low cost. Autologous grafts (iliac bone, split bone flap, pericranium...) have the best features but irradiated heterologous bone can be used instead; the latter needs a particular organization (bone graft bank) to fill the strict conditions of safety, especially regarding the risks of virus transmission. Implants have more recently been developed (acrylic, coral, B.O.P., ceramic, collagen-vicryl...) and present some drawbacks: generally high cost and not well established or insufficient biological properties. The experience of French neurosurgeons is reported from a questionnaire (102 answers) on the most frequently used materials. Autologous bone grafts, and acrylic as bone substitutes and pericranium for dural repair are preferentially used. Some materials, including coral, B.O.P. and collagen-vicryl, have a decreasing utilisation because of poor results especially with regards to bone incorporation and water tightness. Particular techniques (acrylic + teflon, acrylic with pre-op external casting and even non-repair of bone defects) are proposed by some neurosurgeons. New materials still under experimentation are finally presented (lyophilized bovine pericardium, collagen IV, polylactic acid).

Biocompatible Materials↗
PubMed1989

Definitive repair in patients with pulmonary atresia and intact ventricular septum.

Between 1977 and 1988, 22 patients underwent definitive repair for pulmonary atresia with intact ventricular septum. Fifteen underwent biventricular repair (mean age 24 months). All had mild to moderate right ventricular hypoplasia at the time of definitive repair. Repair consisted of closure of the atrial septal defect with enlargement of the right ventricular cavity and outflow tract with a patch in eight, insertion of a valved homograft in three, and superior vena cava-pulmonary artery connection in four. There was one operative death (7%). Seven patients had severe right ventricular hypoplasia at the time of definitive repair and underwent a Fontan procedure (mean age 46 months). In two a valved connection was made to the right ventricle and in five a right atrial-pulmonary artery nonvalved connection. There were two operative deaths (29%). Three patients had right ventricular-coronary sinusoids: Two of them underwent a Fontan procedure and one a biventricular repair. We conclude that with adequate early palliation a biventricular repair may be successfully performed for patients with mild or moderate right ventricular hypoplasia, and the Fontan procedure may be used for those with severe right ventricular hypoplasia.

Child↗
PubMed1989

[An MRI study of the cervical segment of the vertebral artery].

MRI appears to be a very valuable examination to study pathology of the vertebral artery. The examination must include T1 and T2 sequences and scans in three planes. The use of oblique scans allows the planes of section to be adjusted to the course of the artery. MRI can therefore demonstrate abnormalities of flow caused by intrinsic or compressive pathology.

Arterial Occlusive Diseases↗
PubMed1988

Lateral approach to the anterior portion of the foramen magnum. Application to surgical removal of 14 benign tumors: technical note.

In surgery, better access to the anterior part of the foramen magnum with less risk to the lower brainstem can be obtained by lateral enlargement of the usual posterior opening. This requires exposure and control of the vertebral artery (VA) and the sigmoid sinus (SS) and, for further enlargement, medial transposition of the VA and section of the SS with inferior petrosal resection. This technique has been applied fully or partially in 14 cases of anteriorly located tumors of the foramen magnum. It widens exposure on the anterior aspect of the neural axis and allows work in a nearly frontal plane.

Adolescent↗
PubMed1988

Madreporic coral: a new bone graft substitute for cranial surgery.

Since 1985, the authors have been using madreporic coral fragments (genera Porites) as a bone graft substitute. Of the 167 coral grafts implanted, 150 were coral "corks" used to obliterate burr holes (diameter 10 mm), five were large implants (length 20 to 40 mm) to repair skull defects, and 12 were coral blocks to reconstruct the floor of the anterior cranial fossa. Previous experimental studies suggested that coral grafts would be well tolerated and become partially reossified as the calcific skeleton was resorbed. The authors describe their experience and detail the main biological properties of these materials, which appear to be very promising for use in cranial reconstructive surgery.

Animals↗
PubMed1988

[Value of the measurement of cerebral blood flow in choosing the operative time of ruptured intracranial aneurysm].

The authors report a series of 135 patients treated between 1984 and 1987, for a ruptured intracranial saccular aneurysm in the Department of Neurosurgery at the Lariboisiere Hospital. The value of C.T. scan and cerebral blood flow measurements (C.B.F.) in predicting the development of vasospasm was studied on 99 cases. The analysis confirmed that the C.T. Scan findings are closely related to vasospasm. A low C.B.F. between the fourth and the eight day following the bleeding was significantly associated with the development of delayed cerebral ischaemia. On the contrary, no relation was found between vasospasm and the C.B.F. measured during the three days following the bleeding. The authors propose to operate without delay on clinical grounds on patients referred during the first three days after the hemorrhage and to decide, on clinical and C.B.F. data, the timing of the intervention for patients admitted after this data, i.e. 35% of their patients.

Cerebral Hemorrhage↗
PubMed1988

[Extracranial meningioma. Apropos of 7 cases; pathogenic, diagnostic and therapeutic problems].

Meningioma is a benign tumor developing in the meningeal layers. Extracranial meningiomas, seven cases of which are reviewed, are often revealed by ENT signs. In the majority of cases they originate from the cranium and histologic diagnosis (particularly of fresh specimens) is often difficult. A CT scan is the examination of choice for assessing possible extension of these tumors. Treatment often involves the combined efforts of a neurosurgical and an otorhinolaryngologic team.

Adolescent↗
PubMed1987

Coarctation repair without cardiac catheterization in infants.

Of 35 infants who underwent an operation for coarctation of the aorta, 15 did not undergo cardiac catheterization before surgery. The diagnoses in all uncatheterized patients were made by clinical examination, chest radiography, ECG, and two-dimensional echocardiography combined with pulsed Doppler echocardiography. Associated anomalies diagnosed by two-dimensional/Doppler echocardiography included a patent ductus arteriosus in all patients, bicuspid aortic valve in six, small ventricular septal defect in four, and complete common atrioventricular canal in one. In no instance was the diagnosis of coarctation in error. In addition, the clinical significance of the ventricular septal defect was judged correctly by two-dimensional echocardiography, and no patient required an early reoperation because of significant left-to-right shunt. Two significant lesions were missed in one patient each: mitral stenosis and aortic stenosis. These diagnoses were missed in patients who were first seen with either profound congestive heart failure or shock. Coarctation of the aorta and associated lesions can be diagnosed accurately by two-dimensional echocardiography. This permits proper patient management without the added risk of cardiac catheterization. Although mitral and aortic lesions may be missed because of low cardiac output, this does not result in management errors.

Aortic Coarctation↗
PubMed1987

Use of in situ pericardium for surgical relief of pulmonary venous obstruction following Mustard's operation.

A technique is described for relief of pulmonary venous obstruction following the Mustard procedure. The functional left atrium is enlarged by using the pericardium in situ. This is expected to allow for growth of the pericardial patch and to avoid recurrent obstructions. This technique has also been used in reoperations for systemic venous obstruction after enlargement of the systemic baffle with a patch.

Heart Atria↗
PubMed1987

Congenital abnormalities of the aortic arch: MR imaging.

Thirty-four patients, 1 month to 63 years old, with known or suspected congenital abnormalities of the aortic arch underwent magnetic resonance (MR) imaging. Sixteen patients were studied retrospectively, 18 prospectively. In all retrospective studies, the aortic arch abnormality was seen with MR imaging. In the prospective studies, MR imaging enabled diagnosis in 15 of 18 (83%) patients. Twenty-nine of 34 patients underwent two-dimensional echocardiography; nine were studied retrospectively, 20 prospectively. In the prospective studies, echocardiography enabled diagnosis in 13 of 20 (65%) patients. Although two-dimensional echocardiography has a high sensitivity in the detection of aortic arch abnormalities in the neonate, arch abnormalities in the neonate, its sensitivity is lower in older children, adults, and postoperative patients. The authors' experience shows that MR imaging is an important, noninvasive modality in the evaluation of older children, adults, and postoperative patients with congenital aortic arch abnormalities.

Adolescent↗