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Biomedical subjects

B George

Publications and source records attributed to B George.

At least 127 records · Page 7Linked to original sources

Phase contrast magnetic resonance of the spinal cord preliminary results in spinal cord arterio-venous malformations.

In spite of the recent advances in neuroradiology including the CT scan and the spin-echo-magnetic resonance (MR), accurate diagnosis of arteriovenous malformations (AVMs) involving the spinal cord is still based on selective angiography. This last procedure is invasive and needs to be repeated during the follow up. Phase contrast angio MR was performed with a 0.5 Tesla unit on 12 patients with an AVM involving the spinal cord (7 intramedullary AVMs, 4 perimedullary fistulas, and 1 dural fistula with perimedullary venous drainage); 4 of these were investigated before and after treatment. Angio MR showed abnormal vascular patterns within the spinal canal in all cases, without distinguishing between arteries and veins; the nidus of the intramedullary AVMs was displayed in all cases. Angio MR provided images of the whole AVMs comparable to the angiographic pictures, in contrast to the spin-echo MR, which provided only discontinued images of the vessels. The efficient range of velocity providing images varied, according to the type of the malformation (slow for dural fistulas, rapid for intra-medullary AVMs). In the 4 patients investigated after treatment, comparison of the images obtained before and after treatment permitted assessment of the degree of occlusion of the malformation. Finally, angio MR as a complement of spin-echo MR can now be used as a reliable tool for detection of spinal cord AVMs, assessing the indication for angiography, and, furthermore, it can probably replace most of the post-operative control angiographies.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Oblique transcorporeal approach to anteriorly located lesions in the cervical spinal canal.

The technique of obliquely drilling out the postero-lateral part of the cervical vertebral bodies is described. It uses the antero-lateral (retro carotico-jugular) approach to control and displace the vertebral artery postero-laterally and to expose the lateral aspect of the vertebral bodies. It provides, through a wide field and with minimal retraction of the carotid artery and the internal jugular vein, an extensive view of the anterior aspect of the spinal cord. It has already been used to treat 15 anterior lesions compressing the spinal cord including neurinomas and osteophytes.

Bone Transplantation↗

Intradural perimedullary arteriovenous fistulae: results of surgical and endovascular treatment in a series of 35 cases.

A series of 35 patients treated for an intradural perimedullary arteriovenous fistula (AVF) between 1970 and 1990 is reported. Angiography was performed on all of the patients, leading to the diagnosis. The patients were classified into Type I (4 patients), Type II (9 patients), and Type III (22 patients). One Type I patient was not treated, two others underwent surgery, and the last one was embolized. All of the Type II AVFs were treated, two by embolization, four by direct surgery, and three by surgery after incomplete embolization. All of the Type III AVFs were treated by endovascular detachable silicone balloon. Complete occlusion of the AVF was achieved in all treated cases of Types I and II AVF and in 15 cases of Type III AVF; for the 6 other cases of Type III AVF, incomplete occlusion was achieved. In the Types I and II AVFs, partial improvement was clinically observed in only half of the patients; the others remained unchanged. The 15 patients whose Type III AVF was completely embolized recovered completely, and four patients with Type III AVF who were incompletely embolized remained unchanged; 2 other patients with Type III AVF worsened after incomplete occlusion, and 1 additional patient died a few hours after an attempt of endovascular occlusion of a cervical Type III AVF. The place of the perimedullary AVFs among the other vascular malformations involving the spinal cord is discussed according to this classification into three types. Their specific diagnostic and therapeutic difficulties are discussed, resulting in a simplified classification including two types of perimedullary AVF.

Adolescent↗

Intraforaminal neurinoma in the lumbosacral region.

A series of 12 patients with intraforaminal neurinomas in the lumbosacral space was reviewed. Our classification according to tumor extension relative to the affected root into intradural intra-arachnoid, intraforaminal extra-arachnoid, and extraforaminal types was useful in determining the best surgical approach to achieve root preservation and minimal postoperative deficits. Where sacrifice of roots was unavoidable, surprisingly few neurological deficits occurred.

Adult↗

Selective endovascular treatment of 71 intracranial aneurysms with platinum coils.

Seventy-one intracranial aneurysms were treated by endovascular techniques, with the placement of minicoils inside the aneurysmal sac. Most aneurysms were manifest by hemorrhage (67 cases), and 43 of these were treated within the first 3 days after presentation. At the 1-year follow-up examination, the outcome was scored as good in 84.5% of cases, but the morbidity and mortality rates were 4.2% and 11.3%, respectively. Twenty-nine aneurysms in the anterior circulation and 42 in the posterior circulation were treated. In this series, 23 patients were classified as Hunt and Hess neurological Grade I, 27 as Grade II, 12 as Grade III, nine as Grade IV, and none as Grade V. Thirty-three aneurysms were less than 10 mm in diameter, 28 were 10 to 25 mm, and 10 were larger than 25 mm. The preliminary results from this study appear to justify the emergency treatment of aneurysms by this approach. Aneurysms in the posterior circulation are particularly well suited for this type of surgery.

Adult↗

[French language Society of Neurosurgery. 44th Annual Congress. Brussels, 8-12 June 1993. Tumors of the foramen magnum].

Since what seems to be the first reported case of foramen magnum (F.M.) tumor by Hallopeau in 1874, literature on tumoral pathology of this region is rather scarce; beside reports of single cases or short series, there are very few large series and most of them are not recent (Meyer et coll., Yasuoka et coll., Guidetti and Spallone). The present report includes 230 cases of extramedullary tumors collected from 21 french departments over the last ten years (series of the French Speaking Society of Neurosurgery = S.N.C.L.F. series). Delimitation of what is called the F.M. region is rarely given in the literature. In this report, the inferior limit is put at the C2 level and the superior one at the ponto-medullary junction and the lower third of the clivus. To belong to the F.M. region, tumor must have its main part or its insertion within these limits even if it extends beyond them. On the contrary, if the gross development is out of these limits but with some extension into the F.M. region, the case is rejected. A chapter of this report deals with the anatomy of the F.M. with emphasis on the points useful for the management of the tumors. Some details are given on the dimensions of the different parts of the F.M. as given by anatomical studies and also by measurements on C.T. scanner and M.R.I. including during flexion and extension of the head. The S.N.C.L.F. series is then analyzed as a whole. It includes 106 meningiomas (M), 49 neurinomas (N), 28 chordomas (Ch), 32 osseous tumors (T.Os) (19 primary and 13 metastasis) and 15 cases considered as uncommon tumors. (T. Part.) (4 melanomas, 3 hemangioblastomas, 3 dermoid or epidermoid cysts, 2 ependymomas, 1 cavernoma, 1 angiomyolipoma and 1 cholesterin cyst). Mean age is 47 years, with a sex ratio F/M of 1.5/1. Duration of symptoms before diagnosis is of 27 months. Topography is classified into 3 groups anterior (70 cases), lateral (142 cases) and posterior (24 cases). A particular definition is given to these localizations, essentially referring to surgical difficulties and specially for meningiomas. The localization of a tumor is defined by the point of attachment to any structure (dura, spinal root, spinal cord); anterior tumors are attached to the F.M. on both sides of the midline; lateral tumors between the midline and the dentate ligament and posterior ones behind the dentate ligament. According to this way of classification, N are always lateral even if they present anterior or posterior extensions.(ABSTRACT TRUNCATED AT 400 WORDS)

Brain Neoplasms↗

[Iatrogenic complications of paraganglioma of the jugular foramen].

Twenty-eight cases of tumours of the paraganglioma of the foramen jugulare arising from the jugular foramen were treated from 1982 to 1990. The follow-up and the iatrogenic effect of embolization, surgery and radiotherapy were studied. Routine pre-operative embolisation has changed the therapeutic approach to these tumours although a certain number of mainly neurological complications still occur (32% of the cases with 18% of major accidents) especially when the internal carotid component must be excluded. Current oto-neurosurgical techniques allow wider and more complete exeresis of the tumour but often lead to neurological deficits involving the facial nerve (45%), the mixed nerves (32%) and/or the XII (18%). These deficits occur due to unavoidable sacrifice or peroperative manipulation. Radiotherapy is an essential therapeutic possibility with only minor complications and can be proposed in cases of inoperable or relapsing tumours or after an incomplete surgical exeresis. Our critical analysis led us to propose the present indications for surgery. Surgery is indicated in patients with two or more of the following criteria: age less than 55, unilateral tumour, a tumour considered to be inoperable, preoperative otoneurological manifestations, invasion of the posterior fossa. In the other cases, radiotherapy remains the indicated therapy. It is effective and should be used more often for inoperable tumours of the para-jugular lymph nodes, for relapses or after incomplete surgical exeresis.

Adult↗

Accidental cannulation of the hepatic vein during pulmonary artery catheterisation--a case report.

A 22-year-old male was admitted to the adult ICU with a diagnosis of massive cardiomegaly and a large left ventricular thrombus, and needed Swan-Ganz catheterisation for proper haemodynamic monitoring. Insertion of the Swan-Ganz catheter resulted in hepatic vein cannulation. Pulmonary artery was successfully cannulated only when the patient was put in the head-up and right lateral position. It is suggested that to increase the success rate of patients with low cardiac output, cardiomegaly or pulmonary hypertension, they be placed in a head-up and right lateral position.

Accidents↗

[Cervical spondylosis. Resection by oblique transcorporeal approach].

Spondylosis at the cervical level inducing anterior spinal cord compression is generally treated by anterior transcorporeal resection of the osteophytic spurs. We report on 12 cases over 2 years in which a new technique has been applied; it uses the lateral approach exposing and retracting laterally the vertebral artery; then, the vertebral bodies are drilled out obliquely from the anterolateral corner to the posterolateral one on the opposite side. The vertebral bodies were drilled using this technique on 1 level in 2 cases, on 2 levels in 4, on 3 levels in 5 and on 4 levels in 1; the C4-C5, C5-C6 and C6-C7 levels were the most frequent sites involved in 9, 8 and 6 cases respectively. No graft or arthrodesis was used since the stability of the spine was never compromised. Improvement of the neurological symptoms was observed in all the cases with the best results achieved on the motor deficit and sphincter disturbances. Every case was controlled by dynamic standard radiographies (flexion-extension), CT scan and MRI. The results were good in all cases in terms of osteophytes resection, spinal cord decompression and spinal stability. This technique of oblique resection of the cervical bodies seems quite efficient to alleviate spondylotic compression of the spinal cord; moreover, it appears simpler and safer than the anterior route since the operative field is much wider with all the vital structures protected and retracted medially and bone grafting is never necessary.

Adult↗

[Surgical treatment of extrinsic and neoplastic vertebral artery compression].

Extrinsic lesions whatever their origin, tumoral or not, inducing a compression of the vertebral artery, are rarely identified as they are uncommon and often not investigated. The surgical exposure of the vertebral artery in its second and third portion, i-e in the transverse canal from C6 to the foramen magnum is considered very difficult if possible. We report on our experience of 142 cases including 120 tumors, 5 osteophytic spurs, 6 fibrous bands, 4 traumatic lesions, 3 craniocervical junction anomalies and 2 nervous elements. Compression was most commonly observed in the third portion (above C2); intermittent compression was rare and always of non tumoral origin. Ischemic events were quite uncommon in the whole series (N = 15). Surgical treatment was decided either to suppress a tumor or to release the arterial compression if it had clearly been demonstrated its relation with vertebrobasilar symptoms. Whatever the reason for surgical indication, the vertebral artery was first controlled, thus allowing to remove the compressive factor safely and as completely as possible. This requires a precise technique which is described. Our experience demonstrates the interest of investigating every lesion developed in the proximity of the transverse canal; it also shows that it is possible and often useful to control the vertebral artery to achieve complete removal of tumors and to preserve the vertebro-basilar flow.

Arterial Occlusive Diseases↗

The long head of the biceps femoris: anatomic basis for its possible use in the construction of an electrically stimulated neoanal sphincter.

Electrical stimulation of the nerve to the gracilis muscle following its transposition around the anal canal creates an artificial sphincter capable of actively opposing intrarectal pressure. Not all patients have an available or suitable gracilis. This paper describes the anatomic basis for the use of the long head of the biceps femoris as a potential electrically stimulated neoanal sphincter. The muscle was found to have an adequate length and a suitable arc of rotation for transposition around the anal canal. In 75 percent of thighs studied the neurovascular anatomy of the long head of the biceps femoris was compatible with its utilization in this manner as an alternative to the gracilis.

Anal Canal↗

[Surgical treatment of radicular sciatica].

The surgical treatment of radicular sciaticas has to be fitted to the patient's mainly functional problem. In every case but the obviously surgical sciaticas due to tumor, surgery and percutaneous techniques must be discussed with regard to the anatomical factors participating in the root compression and the patient tolerance to his pain. The surgical approach is now limited but the disc removal must be extensive. Complications are very rare, especially infectious ones. Failures account for less than 10% in case of good indications and are related to recurrence of disc herniation and to so-called fibrosis. The operative results are to a large extent related to the patient's psychological profile and his active involvement in the treatment.

Humans↗

Intra-operative monitoring of the facial nerve with an air inflated balloon. Technical note.

A simple, reliable and cheap device for intra-operative monitoring of the facial nerve during surgery for cerebellopontine angle tumours is presented. It consists of a single use tracheostomy tube with a low pressure air inflatable cuff placed in the mouth of the patient on the side of the tumour, connected by a pressure transducer to a monitoring unit. It records any pressure changes in the patient's mouth induced by muscular contractions as a result of excitation of the inferior parts of the facial nerve.

Equipment Failure↗

Jugulare foramen paragangliomas.

A survey is given of the clinical picture, diagnosis and management of foramen jugulare paragangliomas (JFP), based on reports of 175 cases from the literature and personal experience of 26 cases. Special emphasis is given to the operative techniques. Improvements of diagnostic possibilities as well as operative techniques, including the pre-operative occlusion of tumour-feeding arteries by endovascular methods have markedly reduced the operative mortality to a rate between 0 and 5 percent. The rate of incomplete removal of C and D tumours dropped to about 15%. But very large and extensive tumours remain a real challenge. Teamwork between neuroradiologists, ENT-surgeons and neurosurgeons is mandatory.

Adolescent↗

Arteriovenous malformations of the posterior fossa.

AVMs of the posterior fossa are reviewed on the basis of personal experience of 47 cases including 2 venous angiomas, 7 cavernous angiomas, 5 arteriovenous fistulas and 33 true arteriovenous malformations and of the few series reported in the literature. MRI is now an indispensable tool to define the exact localization of any malformation. Combined with angiography, it permits one to choose the most adequate therapeutic strategy and the best surgical approach. Radical cure is to be contemplated in most cases considering the often dramatic consequences of bleeding at the infratentorial level. Deep AVMs and moreover cavernous angiomas, even those located in highly functional structures such as the brain stem, can now be discussed for treatment. Encouraging results have already been obtained using, alone or in association, the recently advanced modalities of treatment: interventional neuroradiology, radiosurgery, and microsurgery.

Brain Neoplasms↗