Venous outflow as a criterion of impairment of cerebral vascular reserve.

AIM: The purpose of this work is to evaluate if the asymmetry of venous outflow between the two hemispheres is a reliable criterion of impairment of the cerebral vascular reserve among symptomatic patients harbouring a spontaneous atherosclerotic occlusion of internal carotid artery. METHODS: From January 1995 to December 2007, 7 symptomatic patients, affected from occlusion of internal carotid artery, were submitted to a low-flow by-pass between the superficial temporal artery and the middle cerebral artery owing to the presence of an impairment of cerebral vascular reserve diagnosed by TC-Doppler, SPECT or perfusion-CT with acetazolamide challenge. Conventional angiography was always performed. Angiographic studies of these patients were reviewed in order to find out the presence of asymmetry of the venous outflow. In the same period 35 patients harbouring an occlusion of the carotid artery in the neck and a normal cerebral reserve underwent cerebral angiography in our departments in Monza. Angiographic studies, of this latter group of patients, were also retrospectively analyzed with the same purpose. RESULTS: All patients, with a poor cerebral reserve, showed an asymmetry of venous outflow >3 s omolateral at the carotid occlusion. Patients, with a normal cerebral reserve, showed an asymmetry of venous outflow <2 s. CONCLUSIONS: Asymmetry of venous outflow were correlated to an impaired cerebral reserve also in chronic conditions as atherosclerotic spontaneous occlusion of internal carotid artery. Our data are a further support to the reliability of this criterion in case of therapeutic sacrifice of internal carotid artery.

Hemodynamic instability after extracranial carotid stenting.

OBJECTIVE: Hemodynamic instability (hypertension, hypotension and bradycardia) is a well-known complication of carotid endarterectomy. Carotid angioplasty and stenting (CAS) is becoming a valuable alternative treatment for patients with severe carotid stenosis and increased surgical risk. CAS implies instrumentation of the carotid bulb, so baroceptor dysfunction may provoke hemodynamic instability. The aim of this work was to calculate the incidence of this complication and to detect factors to predict it. METHODS: Medical records and angiograms of 51 consecutive patients submitted to CAS for severe atherosclerotic stenosis (40 cases) or postsurgical restenosis (11 cases) were retrospectively reviewed in order to detect the occurrence of intra- and post-procedural hypertension (systolic blood pressure >160 mmHg), hypotension (systolic blood pressure <90 mmHg) and bradycardia (heart rate <60 beats/min). The relationship between clinical, procedural and angiographic factors and the occurrence of hemodynamic instability was assessed with univariate and multivariate analysis (logistic regression). RESULTS: Transient mild systolic post-procedural hypertension occurred in five cases (10%); preprocedural hypertension, asymptomatic stenosis and ipsilateral post-surgical restenosis predicted this. Hypotension with bradycardia also occurred in five cases (10%), one with neurological sequelae. Transient periprocedural bradycardia occurred in 19 cases (37%). Severe bradycardia without hypotension arose in one case only. Factors predicting post-procedural hypotension included the presence of a fibrous plaque and the ratio between the pre- and post-stenting diameter of the internal carotid artery. Peri-procedural bradycardia predicted post-procedural bradycardia. None of these factors were confirmed by multivariate analysis as a significant prognostic predictor. CONCLUSION: Mild systolic hypertension may occur after CAS, but is resolved by medical treatment. Prolonged hypotension and bradycardia may also arise and this can be dangerous because it may cause neurological deterioration due to hypoperfusion. These complications cannot be predicted by clinical, procedural, and angiographic factors.

Early invasive treatment (endarterectomy vs. stenting) of moderate-to-severe carotid stenosis in patients with transient ischaemic attack or minor stroke.

Carotid endarterectomy (CA) is an effective treatment for the secondary prevention of stroke in patients with carotid stenosis >50%. More recently, carotid angioplasty with stenting (CAS) has been introduced and found to be effective in case series and small clinical trials. Although CAS has been shown not to be inferior to CA, the comparative effects of early treatment (i.e., during the first month after transient ischaemic attack (TIA) or minor stroke) with these techniques are unknown. Early treatment is advocated, as recurrent stroke tends to present frequently in this time period. On this background, we designed a randomised clinical trial comparing the efficacy and safety of CA vs. CAS in patients who had suffered TIA or minor stroke in the antecedent month. The study design and methods of this multicentre pragmatic randomised parallel-group open trial are presented here.

Stenting of atherosclerotic stenoses of the extracranial carotid artery.

BACKGROUND: Percutaneous transluminal angioplasty (PTA) and stenting seems to be, at present, the treatment of choice for early restenosis after endarterectomy and for atherosclerotic stenoses of supra-aortic trunks near or at the ostium. In contrast, the role of PTA and stenting for treatment of symptomatic and asymptomatic atherosclerotic stenosis of carotid bifurcation is still debated. METHODS: The present study comprises 27 consecutive cases of atherosclerotic lesions of the carotid bifurcation treated with PTA and stenting. All patients were symptomatic, except for 2 suffering from asymptomatic stenosis with contralateral carotid occlusion. There were 23 stenoses occluding 70% or more of the lumen according to the NASCET criteria and 4 mild stenoses (50-60% of the lumen) with large type C ulcers. Criteria for exclusion from surgery in these cases were aged >79 years, previous neck surgery for laryngeal cancer, carotid bifurcation at C2, association with intracranial aneurysms, occlusion of the contralateral carotid artery, and heart, lung and kidney diseases. All procedures were performed under local anaesthesia associated with mild sedation in a few cases. In all cases, self-expandable stents (Wallstent) were used. Follow-up ranged from 6 to 37 months. FINDINGS: Transient neurological deficit occurred in 3 cases (11%). One case (3.7%) experienced a minor stroke at three months. Asymptomatic tight restenosis due to intimal hyperplasia occurred in one case (3.7%). In 8 cases (40%) of complex stenosis involving common and internal carotid arteries there was some loss of contact of the stent with the wall of the common carotid artery in the late follow-up. One case (3.7%) experienced severe and prolonged hypotension and bradycardia during the release of the stent. INTERPRETATION: From literature data and our results it emerges that periprocedural catastrophic embolism is unlikely to occur. The best results are undoubtedly obtained when treating stenosis limited to the internal carotid artery. Nevertheless, the ideal stent to treat vessels of different calibre, as occurs at the carotid bifurcation, is not yet available. The problem of periprocedural cerebral protection has not been resolved. Reported series are heterogeneous and retrospective, and an adequate follow-up of cases is still lacking.

Surgery and stenting As combined treatment of a symptomatic tandem stenosis of the carotid artery.

International co-operative studies have demonstrated a benefit from surgery for symptomatic and asymptomatic patients affected by internal carotid artery stenosis of 60-70%. The presence of a tandem lesion, intracranial or extracranial, may annul the benefit of surgery. Such patients may thus represent a challenging problem for management if age, good general conditions and a normal neurological status favour a therapy. A 54-year-old man developed transient ischaemic attacks of the left hemisphere; his general condition was good, and neurological status was normal. Angiography showed a tight stenosis at the left common carotid artery near the ostium and at the homolateral carotid bifurcation. At first, a self-expanding wall stent was placed at the level of the common carotid artery stenosis, and immediately after a standard endarterectomy under general anaesthesia was performed. The postoperative course was normal and was complicated only by the presence of a mild deficit of the hypoglossal nerve due to the presence of a high bifurcation. The early and late outcome of our case suggests that stenosis of the proximal common carotid artery may be successfully treated by stenting. While awaiting additional data about this new technology, endovascular techniques and surgery may be complementary in the management of patients suffering from such tandem lesions.

Dissecting vertebral aneurysm. Report of a case.

Aneurysms of the vertebral artery (VA) are relatively uncommon, accounting for less than 0.5-3.0% of all aneurysms and 20% of aneurysms originating in the posterior fossa. There are three distinct forms of aneurysms: saccular, fusiform and dissecting. The diagnosis of dissecting aneurysm is based on the findings of angiography, surgery and autopsy. Irregular fusiform appearance, intramural retention of contrast medium in the venous phase and alternating irregular stenotic and dilated segment (string and pearl sign) are the basal angiographic findings. Patients with dissection of VA often develop subarachnoid hemorrhages (SAHs), with the typical neck pain or suffer cerebral ischemia. Because of the high risk of rebleeding of dissecting aneurysms, they should be treated as soon as possible, with occlusion of the VA. Nowadays, both surgical and endovascular procedures allow the treatment of dissecting vertebral aneurysms. Anyway, one should be aware that vertebral occlusion performed proximal to PICA origin may be followed by ischemic complications. In this paper, we discuss the diagnostic and therapeutic difficulties associated with dissecting vertebral aneurysms on the basis of personal observation and a review of the literature.

Incidence of asymptomatic berry aneurysms among patients undergoing carotid endarterectomy.

BACKGROUND: Scattered reports of literature suggest the hypothesis that patients suffering from a severe stenosis of extracranial carotid artery may present an increased rate of intracranial berry aneurysms caused by the hemodynamic stress on the side opposite to the stenosis, namely on physiological shunts. However, this hypothesis has never been verified upon a large and homogeneous series focused on the argument. MATERIALS AND METHODS: We reviewed a consecutive series of 405 patients submitted to carotid endarterectomy for stenosis greater or equal to 70%. RESULTS: Thirteen aneurysm were found in 11 patients (2.6%). Our patients showed a slight increase of incidence regards to general population (1%), maybe due to the large number of aged patients among our subpopulation. Preoperative TCD evaluation showed the presence of increased flow velocities in the physiological shunts, namely the anterior cerebral artery and the anterior communicating artery, in 65% of the patients, and angiography confirmed the redistribution of intracranial circulation. Nevertheless, according to aneurysm location, no statistically significant correlation (0.3 < p < 0.4) was found between the presence of an aneurysm and the values of velocity in these arteries. CONCLUSIONS: As regards the etiology of berry aneurysms, these data suggest that increased hemodynamic stress per se is not sufficient to cause the origin of berry aneurysms. Maybe, a role is possible only if either congenital, or acquired and age-related factor, peculiar of cerebral arteries, coexist.

Management of symptomatic carotid stenoses with coincidental intracranial aneurysms.

There are at present strong indications for surgery in patients suffering from symptomatic extracranial carotid stenoses of > 70%. Surgery of coincidental aneurysms is a still debated problem, but there is general agreement that it is indicated in selected cases according to the patient's life-expectancy and size and site of the aneurysm. The coexistence of these two lesions raises a decision-making problem. We reviewed 389 endarterectomies and found 12 intracranial berry aneurysms in 10 (2.6%) patients. All the 10 patients were harbouring a symptomatic carotid stenosis of > 70%. Since the correction of a stenosis increases blood flow to an aneurysm, our approach was to first operate on the intracranial lesion and then the stenosis in 7 patients harbouring aneurysms > 5 mm. Two patients affected by small aneurysms < 5 mm of an A2 azygos and left internal carotid artery underwent left endarterectomy only. The last patient was submitted first to percutaneous angioplasty of a left stenosis, then to open surgery of a contralateral middle cerebral aneurysm and finally to intravascular occlusion of a small aneurysm of the left internal carotid bifurcation by menas of a coil; this policy was adopted in order to restore normal haemodynamic conditions before the intracranial procedure. There was no mortality or permanent morbidity following surgery for aneurysm or endarterectomy. Transient morbidity occurred in 2 cases after clipping of aneurysms of the anterior communicating and middle cerebral arteries. Our results suggest that surgery of coincidental aneurysms may give good results even when there is a severe symptomatic stenosis in the neck. Moreover, the presence of a small intracranial aneurysm does not seem to be an additional risk factor for endarterectomy. When the lesions are on different sides, it may be better to treat the stenosis first if it decreases the ipsilateral cerebral blood flow.

The transcallosal approach for lesions affecting the lateral and third ventricles. Surgical considerations and results in a series of 42 cases.

The study was carried out on a series of 42 patients who underwent surgery through a midline approach. Lesions were in the anterior part of the third ventricle in 32 cases, in the frontal horns in 6, in the trigone in 3, and in both lateral and third ventricles in 1 case. The third ventricle was approached through Monro's foramen in 22 cases and through an interfornicial route in 9 cases. Surgical mortality occurred in 2 cases (5%). Permanent morbidity occurred in another 2 cases (5%): it consisted of slight intellectual deterioration in one case and slight fixed pyramidal signs in the other. Transient mutism was the most frequently observed postoperative complication. Thirty-one patients were reviewed and submitted to neuropsychological tests in the late postoperative period to investigate the presence of intellectual deterioration or disturbances in the interhemispheric transfer of motor, somataesthetic and visual information. All patients showed only the presence of short-term memory disturbance. Furthermore, 12 patients tested before surgery also showed the presence of short-term memory deficits in the preoperative period. We conclude that a midline approach is the most direct and safe route to the third ventricle as well as to the frontal horns and trigone.

Treatment of colloid cysts of the third ventricle by aspiration in stereotactic conditions.

Two cases of colloid cysts of the third ventricle are reported. The etiology, clinical symptoms and radiological diagnosis of such lesions are briefly discussed. CT-guided stereotactic aspiration of the cyst's content was performed, with good results in both cases. CT-scan controls performed one year later showed that refilling of the cysts did not occur. The advantages of the technique are described. Review of the literature showed another 17 cases successfully treated by means of stereotactic aspiration. The reliability of this approach is supported by the good outcome and the long follow-up of cases previously reported by other Authors. In our opinion, stereotactic aspiration should thus be the first step in the management of colloid cysts.

Early postoperative angiographic findings after carotid endarterectomy.

This report reviews the early postoperative evaluation of 70 patients who underwent carotid bifurcation endarterectomy within our department (before patients' releasing). Angiography was performed by femoral catheterization or the retrograde brachial route; three times only digital venous techniques were employed. No complications due to radiological procedures occurred. Postoperative angiographic findings include asymptomatic occlusion of ICA, occlusion of ECA, the presence of mural thrombi, diffuse surface roughness, intimal flaps and kink of ICA. Dilatation of the arteriotomized segment was detected with a high rate of frequency. Postoperative vascular changes are then analyzed in relation to surgical techniques, to early postoperative clinical course and to the occurrence of late re-stenoses.

Intracranial fibromuscular dysplasia. Report of two cases and review of literature.

Intracranial fibromuscular dysplasia (IFMD) is a rare angiopathy of unknown origin primarily affecting children and young women. We report here on two cases of IFMD; the patients, two females, aging 29 and 25 years, suffered from acute, complete stroke. In one of them emergency extra-intracranial by-pass was attempted without evidence of positive influence on the patient's outcome. In both patients angiography showed the pathognomonic sign of "string of bead" at the level of intracerebral arteries. Cases of IFMD previously reported in the literature are then reviewed and etiology, clinical presentation, pathology, diagnosis and possible treatment of this rare disease are discussed.

Normal pressure hydrocephalus: relationship among clinical picture, CT scan and intracranial pressure monitoring.

Fifty-five patients suffering from normal pressure hydrocephalus were considered. All patients underwent chronic intracranial pressure (ICP) monitoring for at least 24 h. The decision to perform surgery was made on the basis of the ICP monitoring data only. A retrospective analysis on clinical pictures, CT findings and ICP monitoring data was carried out in the attempt to find more selective criteria, in order to submit patients to chronic ICP monitoring. Clinical findings showed controversial data, whereas the enlargement of the III ventricle showed a strict, but not absolute, correlation to pathological pressure profiles. The follow-up of non-shunted patients is briefly discussed.

Course of intracranial pressure after extirpation of posterior fossa tumours.

Forty-seven patients with posterior fossa tumours underwent continuous monitoring of intracranial pressure (ICP) in the early postoperative period by means of an intraventricular catheter. ICP values were very low on the day of operation and subsequently became normal in 37 patients. ICP values were raised in 10 patients. The relationship between the ICP and the clinical course was investigated. Patients were subdivided according to the clinical postoperative course into three groups: good, temporarily deteriorated, poor clinical course. The two first groups showed lower values in the ICP than he third one, nevertheless the relationship between the ICP and the postoperative clinical course is marked but not strict. Our data may have some clinical relevance for the treatment of hydrocephalus before extirpation of posterior fossa tumours.

Multiple meningiomas. Report of nine cases.

Multiple meningiomas are a seldom encountered neoplasm. Most authors report an incidence ranging from 1 to 3% of all meningiomas. The routine use of CT has resolved diagnostic problems involved with multiple meningiomas; nevertheless, they still present several nosologic problems. In fact, it may be difficult to differentiate "true multiple meningiomas", defined as a distinct entity by Cushing in 1938, from simple recurrences or the special variant (forme fruste) of von Recklinghausen's disease. Our report deals with nine cases of multiple meningiomas selected from a series of 372 meningiomas operated from 1968 to 1981 at our hospital. Cases were divided into a) multiple simultaneous meningiomas (five cases), b) multiple meningiomas successively detected at different localizations (two cases), and c) multiple meningiomas associated with neurofibromatosis (two cases). Only five of these nine cases, four from the first group and one from the second, were true multiple meningiomas. Pathogenetic factors related to true multiple meningiomas are discussed in relation to the literature reports. However, the different hypotheses proposed do not offer a definite explanation of the multicentricity of these tumours.

Septum pellucidum oligodendroglioma. Case report and review of literature.

Neoplasms of septum pellucidum are rare. Only 124 cases have been published to which we must add the present case report. The literature is concerned with subependymomas and glioblastomas in most cases; there are only 13 cases of oligodendrogliomas. Surgical removal was performed in about 60 cases. This report presents one case of oligodendroglioma of the septum pellucidum which was surgically removed; it demonstrates the peculiar angiographic features of this kind of tumor, stresses the importance of CT scan in the determination of the possibility of surgical removal and finally discusses the therapeutic problems involved.