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Biomedical subjects

Luca Remonda

Publications and source records attributed to Luca Remonda.

30 records · Page 2Linked to original sources
PubMed2004

Preoperative transarterial embolization of vertebral metastases.

The aim of this study was to evaluate the impact of preoperative devascularization of spinal metastases in relation to the preembolization tumor vascularization degree and in relation to the intraoperative blood loss. Twenty-four patients underwent preoperative transarterial embolization of hypervascular spinal metastases. Each tumor was assigned a vascularization grade (I-III) according to tumor blush after contrast agent injection in the main feeding artery. Embolization was performed with polyvinyl alcohol particles in all patients. Surgical reports were reviewed in terms of estimated blood loss. A mild hypervascularization was found in three patients (group I), medium in six patients (group II) and extensive in 15 patients (group III). In 22 out of 24 patients embolization could be performed with a complete devascularization. In two patients, only partial embolization could be performed, due to the main feeding artery arising from the artery of Adamkiewicz. In patients with complete devascularization the mean intraoperative blood loss was 1,900 ml, whereas in the two patients who were not embolized it was 5,500 ml. Intraoperative blood loss was not correlated to the vascularization grade. Angiography and embolization could be performed in all patients without causing permanent neurologic deficit, skin or muscle necrosis. The surgeons concluded that radical tumor resection after embolization was facilitated. Intraoperative blood loss is not correlated with the pre-interventional vascularization degree, if complete devascularization can be achieved with embolization. Preoperative embolization of vertebral hypervascular tumors is safe, effective and facilitates tumor resection.

Adult↗
PubMed2004

Volumetry and diffusion tensor imaging of hippocampal subregions in schizophrenia.

Previous MRI-volumetric studies in schizophrenic psychoses have demonstrated more or less pronounced volume reductions of the hippocampus in patients. Correspondingly, neuropathological examinations on the brains of schizophrenics showed diverse structural changes of the hippocampus. Employing a high-resolution 3D-MPRAGE sequence, we found volume reductions in most hippocampal subregions of schizophrenic patients, which, however, did not reach significant levels. An analysis of co-registered diffusion tensor imaging (DTI) data revealed significant alterations of the inter-voxel coherences in single hippocampal subdivisions of these patients, supporting the assumption of characteristic microstructural tissue changes relevant for the pathogenesis of schizophrenic psychoses. Our results argue for the usage of additional MRI modalities like DTI in order to detect subtle regional alterations of hippocampal structure in schizophrenics.

Adult↗
PubMed2004

Outcome of acute stroke patients without visible occlusion on early arteriography.

BACKGROUND: The aim of this study was to determine the clinical and radiological outcome of acute stroke patients who had no vessel occlusion on arteriography and to define predictors of clinical outcome. METHODS: We analyzed clinical and radiological data of stroke patients whose arteriography performed within 6 hours of symptom onset did not visualize any vessel occlusion. RESULTS: Twenty-eight of 283 consecutive patients (10%) who underwent arteriography with the intention to perform intraarterial thrombolysis did not show any arterial occlusion. Their median baseline National Institutes of Health Stroke Scale (NIHSS) score was 7. Time from symptom onset to arteriography ranged from 115 to 315 minutes; on average, it was 226 minutes. Presumed stroke cause was cardiac embolism in 11 patients (39%), small artery disease in 6 (21%), coronary angiography in 1 (4%), and undetermined in 10 patients (36%). After 3 months, modified Rankin Scale score (mRS) was < or =2 in 21 patients (75%), indicating a favorable outcome. Six patients (21%) had a poor outcome (mRS 3 or 4) and 1 patient (4%) had a myocardial infarction and died. Twenty-seven patients had follow-up brain imaging. It was normal in 5, showed a lacunar lesion in 8, a striatocapsular infarct in 2, a small or medium-sized anterior circulation infarct in 6, multiple small anterior circulation infarcts in 2, and multiple posterior circulation infarcts in 4. No predictors of clinical outcome were identified. CONCLUSIONS: Most acute stroke patients with normal early arteriography show infarcts on brain imaging; however, clinical outcome is usually favorable.

Adolescent↗
PubMed2004

Differentiating hippocampal subregions by means of quantitative magnetization transfer and relaxometry: preliminary results.

The hippocampal formation (HF) of healthy control subjects and schizophrenic patients was examined using an MRI experiment that implements sequences for relaxometry and magnetization transfer (MT) quantification. In addition to the semi-quantitative magnetization transfer ratio (MTR), all of the observable properties of the binary spin bath model were included. The study demonstrates that, in contrast to the MTR, quantitative MT parameters (especially the T2 relaxation time of restricted protons, T2b) are capable to differentiate functionally significant subregions within the HF. The MT methodology appears to be a promising new tool for the differential microstructural evaluation of the HF in neuropsychiatric disorders accompanied by memory disturbances.

Adult↗
PubMed2003

Pre- and in-hospital delays from stroke onset to intra-arterial thrombolysis.

BACKGROUND AND PURPOSE: Thrombolysis for treatment of acute ischemic stroke should be administered as fast as possible after symptom onset. The aim of this study was to examine, in our tertiary care center, the time intervals preceding intra-arterial thrombolysis in order to accelerate and optimize the management of acute strokes. METHODS: Between January 1, 2000, and April 30, 2002, 597 patients with acute stroke were admitted to our stroke center. One hundred forty-eight patients underwent diagnostic arteriography, and 100 (16.8%) received intra-arterial thrombolysis. For all patients, we prospectively recorded and analyzed the time of symptom onset, admission, CT and/or MRI scan, diagnostic arteriography, and, if performed, intra-arterial thrombolysis. RESULTS: The mean time to arrival in the emergency department was 99 minutes for patients who were admitted directly (Bern patients), 127 minutes for those who were referred from community hospitals without a CT scanner (non-Bern/-CT patients), and 210 minutes for patients from hospitals with imaging facilities (non-Bern/+CT patients). The mean delay from symptom onset to treatment was 234 minutes for Bern patients, 269 minutes for non-Bern/-CT patients, and 302 minutes for non-Bern/+CT patients. The patients from the last group needed longer to receive intra-arterial thrombolysis than did patients who were admitted directly (P=0.002) or who were transferred from a hospital without a CT scanner (P=0.03). CONCLUSIONS: This prospective study indicates that direct referral without prior imaging at community hospitals shortens the time until intra-arterial thrombolysis. In addition, our in-hospital delay preceding intra-arterial thrombolysis is longer than the delays reported for intravenous thrombolysis and indicates potential for improvement.

Aged↗
PubMed2002

Fast contrast-enhanced MR whole-brain venography.

Our aim was to assess the value of a new fast contrast-enhanced MR venography (CE-MRV) sequence in the investigation of normal and diseased cerebral veins. Conventional time-of-flight (TOF) MRV is time consuming, with imaging for a single sequence taking many minutes. MRI was performed with a clinical 1.5-T scanner; conventional TOF MRV followed by CE-MRV was performed using a modified 3D first-pass MR angiography sequence. Ten control subjects without cerebral pathology were studied as well as ten patients with cerebral venous thrombosis for a total of 20 studies with both sequences. CE-MRV was able to provide a set of complete MRV images in a significantly shorter time than conventional MRV sequencing could. The field of view also provided greater coverage of the vessels of the head and neck. CE-MRV also provided more extensive small vein detail and provided a better demonstration of intraluminal defects, despite a slightly lower resolution. Both methods were equally suited for the demonstration of venous thrombosis and demonstrated all cases equally well; however, CE-MRV provided more detailed information by showing partially obstructed sinuses and by showing better the presence of cortical collateral venous drainage.

Adolescent↗
PubMed2002

Non-traumatic neurological emergencies: emergency neuroradiological interventions.

This article summarizes recent developments in the growing field of interventional neuroradiology for the treatment of acute cerebrovascular disease. We describe the possibilities in endovascular therapy of acute cerebral aneurysms using electrolytically detachable coils combined with trispan neck bridging devices and stent implantation to occlude acute wide neck aneurysms. Techniques and results of local intra-arterial thrombolytic therapy in acute stroke and central retinal artery occlusion are described and we discuss the potential for rapid, large-burden thrombus removal in cases of internal carotid artery thrombosis by rheolytic thrombectomy, percutaneous transluminal angioplasty and stent implantation. Emergency endovascular therapy using the transvenous approach to treat severe intracranial or intraocular hypertension and multifocal haemorrhagic venous infarction due to cerebral sinus thrombosis or dural fistulas is also described. In cases of acute bleeding of head and neck lesions following trauma, tumours after radiotherapy, arteriovenous malformations, epistaxis or from iatrogenic origin, angiography plays a major role in localizing the source of bleeding and occluding the damaged vessel during the same session using the same endovascular approach.

Adolescent↗
PubMed2002

Thrombolysis in patients with acute stroke caused by cervical artery dissection: analysis of 9 patients and review of the literature.

BACKGROUND: Results of recently published studies suggest that intravenous thrombolysis (IVT) and local intra-arterial thrombolysis (LIT) are feasible procedures in acute stroke after cervical artery dissection (CAD). OBJECTIVES: To describe 9 patients with acute stroke caused by CAD who were treated by LIT (n = 7) or IVT (n = 2) and to review the literature. METHODS: Retrospective analysis of clinical and neuroradiological findings; literature review from 1980 to present. MAIN OUTCOME MEASURE: Modified Rankin Scale (mRS) score. RESULTS: Of 7 patients treated with LIT, 3 had good outcomes (mRS score of 0-2) and 4 had bad outcomes (mRS score of 3-6) at 3 months. The 2 patients who had received IVT recovered to mRS scores of 0 and 3. Twenty-one patients were identified in the literature. Overall (N = 30), in the IVT group (n = 19), the outcome was good in 8 patients (42%) and bad in 11 (58%); in the LIT group (n = 11), 6 patients (55%) had a good outcome and 5 (45%) had a bad outcome. Overall, 47% (14/30) of the patients (IVT and LIT groups) had a good outcome. Total mortality was 13% (4/30). There were no secondary complications due to extension of wall hematoma or angiography. One symptomatic hemorrhage occurred. CONCLUSIONS: Thrombolysis is feasible in acute stroke caused by CAD. Local complications from extension of wall hematoma did not occur. Further prospective studies are needed to determine the safety and efficacy of thrombolysis in the special circumstance of acute stroke caused by CAD.

Acute Disease↗
PubMed2002

Duplex sonographic criteria for measuring carotid stenoses.

PURPOSE: The aim of this retrospective study was to determine optimal duplex sonographic criteria for use in our institution for diagnosing severe carotid stenoses and to correlate those findings with angiographic measurements obtained by the European Carotid Surgery Trial (ECST), North American Symptomatic Carotid Endarterectomy Trial (NASCET), and Common Carotid (CC) methods of grading carotid stenoses. METHODS: We analyzed the angiographic data using the ECST, NASCET, and CC methods and compared the results with the duplex sonographic findings. We then calculated the sensitivity, specificity, positive and negative predictive values, and accuracy of the duplex sonographic method. Taking these parameters into account, the optimal intrastenotic peak systolic velocity (PSV) and end diastolic velocity (EDV) were derived for diagnosing severe stenoses according to the 3 angiographic methods. RESULTS: Optimal PSV and EDV values for diagnosing a 70% or greater stenosis in our laboratory were as follows: with the NASCET method of angiographic grading of stenoses, PSV 220 cm/second or greater and EDV 80 cm/second or greater, and with the ECST and CC methods, PSV 190 cm/second or greater, and EDV 65 cm/second or greater. The optimal PSV and EDV for diagnosing a stenosis of 80% or greater with the ECST grading method were 215 cm/second or greater and 90 cm/second or greater, respectively. CONCLUSIONS: Duplex sonography is a sensitive and accurate tool for evaluating severe carotid stenoses. Optimal PSVs and EDVs vary according to the angiographic method used to grade the stenosis. They are similar for stenoses 70% or greater with the NASCET method and for stenoses 80% or greater with the ECST method.

Aged↗
PubMed2002

Intra-arterial thrombolysis in 100 patients with acute stroke due to middle cerebral artery occlusion.

BACKGROUND AND PURPOSE: The purpose of this study was to evaluate the safety and efficacy of local intra-arterial thrombolysis (LIT) using urokinase in patients with acute stroke due to middle cerebral artery (MCA) occlusion. METHODS: We analyzed clinical and radiological findings and functional outcome 3 months after LIT with urokinase of 100 consecutive patients. To measure outcome, the modified Rankin scale (mRs) score was used. RESULTS: Angiography showed occlusion of the M1 segment of the MCA in 57 patients, of the M2 segment in 21, and of the M3 or M4 segment in 22. The median National Institutes of Health Stroke Scale (NIHSS) score at admission was 14, and, on average, 236 minutes elapsed from symptom onset to LIT. Forty-seven patients (47%) had an excellent outcome (mRs score 0 to 1), 21 (21%) a good outcome (mRs score 2), and 22 (22%) a poor outcome (mRs score 3 to 5). Ten patients (10%) died. Excellent or good outcome (mRs score < or =2) was seen in 59% of patients with M1 or M2 and 95% of those with M(3) or M(4) MCA occlusions. Recanalization as seen on angiography was complete (thrombolysis in myocardial infarction [TIMI] grade 3) in 20% of patients and partial (TIMI grade 2) in 56% of patients. Age <60 years (P<0.05), low NIHSS score at admission (P<0.00001), and vessel recanalization (P=0.0004) were independently associated with excellent or good outcome and diabetes with poor outcome (P=0.002). Symptomatic cerebral hemorrhage occurred in 7 patients (7%). CONCLUSIONS: LIT with urokinase that is administered by a single organized stroke team is safe and can be as efficacious as thrombolysis has been in large multicenter clinical trials.

Adult↗
PubMed2002

Contrast-enhanced 3D MR angiography of the carotid artery: comparison with conventional digital subtraction angiography.

BACKGROUND AND PURPOSE: Since 1996, several preliminary studies have shown the usefulness of contrast material-enhanced MR angiography for imaging supraaortic vessels. The aim of this study was to compare the accuracy of contrast-enhanced 3D MR angiography with that of digital subtraction angiography (DSA) in the evaluation of carotid artery stenosis. METHODS: A blinded comparison of first-pass contrast-enhanced MR angiography with conventional DSA was performed in 120 patients (240 arteries). MR angiography was performed with a 1.5-T magnet with gradient overdrive equipment, by using a coronal radiofrequency-spoiled 3D fast low-angle-shot sequence after the intravenous injection of gadodiamide. The guidelines of the North American Symptomatic Carotid Endarterectomy Trial for measuring stenosis of the internal carotid artery were applied on maximum intensity projection (MIP) images and conventional catheter angiograms. RESULTS: Grading of stenoses on MR angiograms agreed with grading of stenoses on DSA images in 89% of arteries. In the severe stenosis group (70-99%), agreement was 93%. All internal carotid occlusions (n = 28) and seven of nine pseudo-occlusions were accurately detected with contrast-enhanced MR angiography. The correlation between MR angiography and DSA for determination of minimal, moderate, and severe stenoses and occlusion was statistically significant (r = 0.91, P<.001). CONCLUSIONS: This investigation with a large number of patients confirms that contrast-enhanced MR angiography could become a diagnostic alternative to DSA in the treatment of patients with carotid artery disease.

Adolescent↗