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Biomedical subjects

B George

Publications and source records attributed to B George.

At least 163 records · Page 9Linked to original sources
PubMed1991

[Intraforaminal lumbosacral neurinoma].

Twelve cases of intra-foraminal localization of lumbosacral neurinoma are reported including 9 schwannomas, 2 neurifibromas and 1 melanotic schannoma. According to their extension, they are classified in type II strictly intra-foraminal and extra-arachnoïdal: N = 6, type I-II, extending into the subarachnoïdal space; N = 5, type II-III, extending out of the spine. There were 7 men and 5 women with mean age of 49.5 years and a 5.2 years delay before diagnosis. The most common, though not permanent, symptom was radiculalgia; a generally weak sensorimotor deficit was noticed in 4 cases and hypoesthesia in two cases. Diagnosis was sometimes doubtful using myelography for the oldest cases, but is now made easily with CT scan and M.R.I. Microsurgery allows to dissect out the tumor inside the perineural sheath and to preserve the nervous root in most cases even in extra-arachnoïdal forms (N = 8). However, in cases of neurofibromas and of large tumors, the root had to be divided (N = 4) with rather surprisingly no new post-operative deficits. Intra-foraminal localization of lombo-sacral neurinomas is rare but now easily identified; it should be cured surgically with the goal, often reached, of maximum preservation of the nervous root.

Adult↗
PubMed1991

[Evaluation of cerebral blood flow in severe brain injuries by SVO2 measurement in the internal jugular vein].

The purpose of the present study was to assess the value of jugular oxyhemoglobin saturation percent (SvO2) in predicting cerebral blood flow (CBF). SvO2 and CBF were measured in 25 adults with acute brain trauma (Glasgow Coma Scale < 8). From the data a classification of CBS and SvO2 was developed: in the first group of patients the presence of cerebral ischemia could be identified in the presence of low CBF (< 40 ml/min/100g) and a low SvO2. In the second group he CBF is closely coupled to and regulated by the cerebral metabolic rate of oxygen (CMRO2) and values of SvO2 are intermediate. In the third group hyperaemia was defined as both an increase of SvO2 and CBF (> 60ml/min/100g) and a decrease of CMRO2. The SvO2 was measured in 18 of these 25 patients following 1) intravenous infusion of mannitol (1 g.kg-1) and hyperventilation (PCO2 = 3.4 kPa). The data suggest that there is no correlation between SvO2 and CBF, but a reliable estimates of CBF may be made from SvO2 measurement after mannitol and hyperventilation.

Blood Flow Velocity↗
PubMed1991

[Emergency preoperative embolization using coils of ruptured sylvian aneurysm. Apropos of a case].

The authors report a case of a 73 year old patient who presented with a right temporal lobe hematoma secondary to rupture of a right middle cerebral artery bifurcation aneurysm. Treatment consisted of partial thrombosis of the aneurysm by the endovascular introduction of metallic coils followed by surgical hematoma evacuation and aneurysm clipping. Thrombus of the aneurysm done probably diminished the risk of intraoperative rupture. Partial endovascular treatment has a very small risk and may be done on a emergency basis at the same time as the diagnostic arteriogram. It can also be suggested for patients in poor condition to diminish the risk of recurrent hemorrhage until the patient is well enough to undergo definitive surgical clipping.

Aged↗
PubMed1990

Partial biventricular repair for double-outlet right ventricle with left ventricular hypoplasia.

The presence of left ventricular hypoplasia in double-outlet right ventricle may increase the risk of biventricular repair and Fontan procedures. The hypoplastic left ventricle of an 11-year-old girl with complex double-outlet right ventricle was successfully incorporated in a modified biventricular repair by Dacron patch closure of the ventricular septal defect, diversion of venous return of the inferior vena cava to the mitral valve with an intraatrial baffle, insertion of a left ventricular apex to pulmonary artery valved aortic homograft, and diversion of residual systemic venous return directly to the lungs with a bidirectional superior vena cava to pulmonary artery shunt. Postoperatively, the systemic venous atrial pressure was 6 mm Hg and the pulmonary artery pressure was 14 mm Hg. This method is proposed as a partial biventricular repair hemodynamically superior to the Fontan procedure, although aortic homograft revision may be required in the future.

Blood Vessel Prosthesis↗
PubMed1990

Stroke and acute myocardial infarction in the thrombolytic era: clinical correlates and long-term prognosis.

Thirteen (1.8%) of 708 patients with acute myocardial infarction treated with recombinant tissue-type plasminogen activator in the Thrombolysis and Angioplasty in Myocardial Infarction (TAMI) I, II and III trials developed a stroke. Four strokes were hemorrhagic and nine were nonhemorrhagic. Of five prespecified risk factors for intracranial hemorrhage (age greater than 65 years, history of hypertension, history of prior cerebrovascular disease, aspirin use and acute hypertension), two patients had two risk factors and one patient had one risk factor. However, 80% of patients without intracranial hemorrhage had at least one risk factor and 31% had two risk factors. No patient with a prior stroke or transient ischemic attack (all greater than 6 months previously) had an intracranial hemorrhage. Of three prespecified risk factors for nonhemorrhagic stroke (atrial fibrillation, prior cerebrovascular disease and large anterior wall infarction), only the occurrence of a large anterior myocardial infarction (with ejection fraction less than 45%) was a predictor (p = 0.0015). The in-hospital death rate was 25% for patients with hemorrhagic stroke versus 11% for patients with a non-hemorrhagic stroke and 6% for those patients without a stroke. Furthermore, the hospital stay was greater than 50% longer in patients who had a stroke than in those who did not. Thus, intracranial hemorrhage remains an unpredictable risk in patients treated with thrombolytic therapy and cerebral infarction is related to anterior myocardial infarction and poor left ventricular function. Both types of stroke are associated with substantial morbidity and mortality.

Aged↗
PubMed1990

Pharmacokinetics of enoxacin and its oxometabolite following intravenous administration to patients with different degrees of renal impairment.

Enoxacin is a fluorinated quinolone with potential clinical use in the treatment of serious infections. Twenty-three patients (age, 19 to 87 years) with different degrees of renal function, including a group undergoing chronic hemodialysis, received enoxacin (400 mg) by intravenous infusion (1 h). Blood samples were collected before infusion; at the end of infusion; and at 5, 10, 20, 30, 45, 60, 90, and 120 min and 3, 4, 6, 12, 18, 24, 48, and 72 h after infusion. Enoxacin and oxoenoxacin concentrations were measured by high-pressure liquid chromatography. Pharmacokinetic parameters (mean +/- standard deviation) were calculated by using a noncompartmental PK model according to creatinine clearances (in milliliters per minute). Total clearance of enoxacin decreased from 4.95 +/- 1.16 ml/min per kg in the group with normal creatinine clearance to 0.76 +/- 0.21 ml/min per kg in the patients with severe renal failure (creatinine clearance, less than 15 ml/min), whereas the elimination half-life increased from 4.5 +/- 1.0 to 20 +/- 5 h, respectively. The elimination of oxoenoxacin (the main metabolite of enoxacin) in urine was markedly decreased when creatinine clearance was less than 15 ml/min. Hemodialysis removed an insignificant amount of enoxacin and oxoenoxacin. These data indicate that as creatinine clearance falls below 30 ml/min, the daily enoxacin dose should be reduced by half. During prolonged administration of enoxacin to patients with creatinine clearances of less than 30 ml/min, the accumulation of oxoenoxacin might lead to unexpected side effects.

Adult↗
PubMed1990

Consequences of reocclusion after successful reperfusion therapy in acute myocardial infarction. TAMI Study Group.

To determine the clinical consequences of reocclusion of an infarct-related artery after reperfusion therapy, we evaluated 810 patients with acute myocardial infarction. Patients were admitted into four sequential studies with similar entry criteria in which patency of the infarct-related artery was assessed by coronary arteriography 90 minutes after onset of thrombolytic therapy. Successful reperfusion was established acutely in 733 patients. Thrombolytic therapy included tissue-type plasminogen activator (t-PA) in 517, urokinase in 87, and a combination of t-PA and urokinase in 129 patients. All patients received aspirin, intravenous heparin and nitroglycerin, and diltiazem during the recovery phase. A repeat coronary arteriogram was performed in 88% of patients at a median of 7 days after the onset of symptoms. Reocclusion of the infarct-related artery occurred in 91 patients (12.4%), and 58% of these were symptomatic. Angiographic characteristics at 90 minutes after thrombolytic therapy that were associated with reocclusion compared with sustained coronary artery patency were right coronary infarct-related artery (65% versus 44%, respectively) and Thrombolysis in Myocardial Infarction (TIMI) flow 0 or 1 (21% versus 10%, respectively) before further intervention. Median (interquartile value) degree of stenosis in the infarct-related artery at 90 minutes was similar between groups: 99% for reoccluded (value, 90/100%) compared with 95% for patent (value, 80/99%). Patients with reocclusion had similar left ventricular ejection fractions compared with patients with sustained patency at follow-up. However, patients with reocclusion at follow-up had worse infarct-zone function at -2.7 (value, -3.2/-1.8) versus -2.4 (SD/chord) (value, -3.1/-1.3) (p = 0.016). The recovery of both global and infarct-zone function was impaired by reocclusion of the infarct-related artery compared with maintained patency; median delta ejection fraction was -2 compared with 1 (p = 0.006) and median delta infarct-zone wall motion was -0.10 compared with 0.34 SD/chord (p = 0.011), respectively. In addition, patients with reocclusion had more complicated hospital courses and higher in-hospital mortality rates (11.0% versus 4.5%, respectively; p = 0.01). We conclude that reocclusion of the infarct-related artery after successful reperfusion is associated with substantial morbidity and mortality rates. Reocclusion is also detrimental to the functional recovery of both global and infarct-zone regional left ventricular function. Thus, new strategies in the postinfarction period need to be developed to prevent reocclusion of the infarct-related artery.

Angiography↗
PubMed1990

[Endovascular treatment of intracranial aneurysms. Value and prospects based on a series of 92 cases].

Endovascular treatment of intracranial aneurysms is a recent technique which needs to be evaluated in large series. From 1978 to 1988, 92 cases of aneurysms were balloon-treated at Lariboisière Hospital either by parent vessel occlusion (O.V.P.) (N = 48) or by selective obliteration (O.S.A.). Treatment in all but 5 cases was performed 3 weeks after S.A.H. since the main reason for choosing endovascular technique was contraindication of early surgery. Giant aneurysms account for 31 cases, vertebro-basilar for 38 and cavernous carotid for 27. In O.V.P. group, there were 17 patients referred after subarachnoid hemorrhage and 30 after tumoral symptoms, while in O.S.A. group, 30 bled and 5 presented with oculomotor palsies. Results in the O.V.P. group are good with 8% morbidity and mortality. In O.S.A., they are worse: 16% (morbidity and mortality) and 22% of secondary balloon deflation; however, because of the features of these aneurysms (size and location), the results seem quite acceptable. Endovascular treatment of intracranial aneurysms is a promising technique which should already replace parent vessel ligation when indicated, and progressively supplant surgical clipping when the remaining technical problems are resolved.

Catheterization↗
PubMed1990

[The use of coral in bone surgery. Results following 4 years of utilization].

The authors have used Porites coral as a bone substitute in more than 200 patients since 1985, initially for reconstruction after craniotomy or removal of graft from the iliac crest. Encouraging results have prompted wider use. No complications have occurred. The biological properties of coral are described. It is easily available and appears to be a promising bone substitute.

Calcium Carbonate↗
PubMed1989

Spinal dural arteriovenous malformations with perimedullary drainage. Indications and results of surgery in 30 cases.

70 patients were treated for spinal dural arteriovenous fistula in the same centre, during a period of 10 years. Conus medullaris and cauda equina syndromes were observed in all patients as the clinical stereotyped presentation. Diagnosis was based on myelography in the first instance and then on angiography. 40 patients were treated by intravascular neuroradiological embolization, whereas the other 30 were operated on. Surgery was proposed because embolization was contraindicated (7 cases of hazardous catheterisation) of inefficient (23 cases = 38%). The results of the operative series are presented, and compared with those of embolization. Improvement was observed in 50% of the 20 patients with follow up, but a complete recovery to an asymptomatic state was never obtained. For the other patients (47%) complete stabilization of the disease could be obtained, whereas in one of the patients (3%), who was operated upon because of failure of embolization, surgery was also completely ineffectual. The long-term results of patients treated surgically are comparable with those patients efficiently embolized. 5 patients of the operative series were submitted to MRI before and after surgery: the results and the place of MRI are discussed.

Adult↗
PubMed1989

Ruptured intracranial aneurysms. The influence of sex and fibromuscular dysplasia upon prognosis.

From a statistical analysis of a series of 214 cases of ruptured intracranial aneurysms, it was demonstrated that only four parameters among those collected on the admission day, are predictive of the final functional result: sex (p less than 0.001); age (p less than 0.02); clinical grade (p less than 0.001) and angiographic spasm (p less than 0.01). The surprisingly poor prognosis in women was explained by the higher frequency of spasm (p less than 0.005). Aneurysms in women predominated on the intracranial carotid artery (38%) and were frequently multiple (12%). A further angiographic study on 87 cases was then carried out including a systematic investigation of the cervical part of the vessels; it permitted one to identify angiographic features of fibromuscular dysplasia (FMD) on the cervical vessels in 20 cases. In those cases it was also observed that there was a marked female predominance (F/M = 5.6), a frequent localization on the internal carotid artery (50%), a high rate of multiple aneurysms (60%) and a poor prognosis related to spasm (50%). Therefore, intracranial aneurysms appear far more frequently than usually reported, to be related to FMD. The worse prognosis of ruptured intracranial aneurysms in females can be, at least partly explained by the association with FMD and the frequent occurrence of spasm. A careful investigation of patients exhibiting features of FMD in order to detect intracranial aneurysms before rupture, is suggested.

Arterial Occlusive Diseases↗
PubMed1989

Surgical options for complex transposition of the great arteries.

Between September 1976 and November 1987, 53 patients underwent surgical treatment by the same surgeon for "complex transposition of the great arteries" with ventricular septal defect or severe left ventricular outflow tract obstruction, or both. Six patients with transposition and left ventricular outflow tract obstruction underwent atrial rerouting and direct relief of the left ventricular outflow tract obstruction. Twenty-two patients presented with transposition plus ventricular septal defect; 15 of these patients underwent atrial rerouting and ventricular septal defect closure and 7 underwent an arterial switch procedure. Twenty-five patients presented with transposition plus ventricular septal defect and left ventricular outflow tract obstruction, 23 of whom underwent a Rastelli procedure. There were one early death (mortality rate 1.9%; 90% confidence limits 0-7%) and three late deaths (mortality rate 5.8%) during a mean follow-up period of 42 months (range 2 to 124). These results show that 1) atrial rerouting is an appropriate surgical procedure for transposition of the great arteries with left ventricular outflow tract obstruction; 2) the arterial switch procedure provides excellent early correction of transposition with ventricular septal defect and is currently the preferred procedure for this lesion; and 3) the Rastelli procedure can be performed with a low early mortality rate and excellent long-term results for transposition with ventricular septal defect and left ventricular outflow tract obstruction.

Adolescent↗
PubMed1989

Impairment of vertebral artery flow caused by extrinsic lesions.

In a consecutive series of 71 cases of extrinsic lesions involving the vertebral artery (VA), 51 patients presented with external compression of this vessel. The compressive agents included 34 tumors, 4 osteophytes, 5 fibrous bands, 4 traumatic lesions, 2 neural elements, and 2 infectious processes. The main site was the second portion of the VA (C2-C6) (30 of 51 patients). Compression always induced at least significant stenosis, and in 8 patients caused complete occlusion. The compression was either permanent (44 patients) or intermittent (7 patients). Symptoms were observed in 11 patients, including 2 with permanent deficits. Surgical release of compression was performed each time symptoms could be explained by a reduction in VA flow and also when the compressing agent needed to be removed, as in the cases involving tumors. VA decompression was achieved by direct approach in 37 patients, by reduction and fixation of a traumatic dislocation in 2 patients, and by distal revascularization in 4 patients. Medical treatment or roentgenotherapy was used in the other patients. Results were excellent in all but 2 patients, who died from traumatic and ischemic lesions, respectively. Therefore, it seems important to identify external causes of compression of the VA for two reasons: 1) to suppress symptoms of vertebrobasilar insufficiency when their relation to VA compression is clearly established, and 2) to remove compressive agents like tumors safely while preserving the VA.

Cervical Vertebrae↗