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Featured researches published by H. Alvarez.


Acta Neurochirurgica | 2005

Supratentorial cerebral arteriovenous fistulas (AVFs) in children: review of 41 cases with 63 non choroidal single-hole AVFs

Y. C. Weon; Y. Yoshida; M. Sachet; J. Mahadevan; H. Alvarez; Georges Rodesch; P. Lasjaunias

SummaryPurpose. In this article we explore the various aspects of the supratentorial Single-Hole AVFs (ST AVFs) in children, focusing on their clinical features, angio-architecture, treatment indications and the role and results of endovascular management.Materials and methods. Among 1565 cases of brain AVMs seen at our neurovascular center, 620 cases were seen in the pediatric age group (≤ to 15 year-old) and 303/620 were non-Galenic brain AVMs. Among 52 brain AVFs found in children, we reviewed 41 pediatric patients with supratentorial single-hole cerebral AVFs (M/F=28/13) with a total of 63 AVFs. Mean age at presentation was 24 months. Four cases had their lesion diagnosed in utero without particular prognostic significance. 17 cases were multifocal with a total of 39 AVFs. The most common clinical presentation leading to diagnosis was cardiac sufficiency in (31.7%), epilepsy (24.4%), macrocrania (14.6%). Venous ectasia (87.8%) and pial venous stenosis (41.5%) were the most frequent angiographic features. There were 11 cases of Hemorrhagic Heriditary Telangiectasia (HHT1) (including two suspicious cases) among the 41 patients (26.8%) and among those 4 cases had single AVFs and 7 cases had multiple AVFs.Results. Thirty-five children were treated in our institution: 34/35 by embolization alone, 1/35 by a combination of embolization and radiosurgery. 32/35 patients were treated with glue alone, 3/35 with coils (2/3 with glue also). A total of 57 separate lesions were treated. On clinical follow up (from 1985–2002, mean 4.2 years), 88.6% of patients proved to be either asymptomatic, improved from previous clinical symptoms or stabilized. 40% of patients had their lesion(s) already completely excluded.Post operative mortality was 5.6% (2/35), permanent neurological morbidity 3% (1/33). Twenty-six of these 33 patients (78.6%) were neurologically normal. 5/33 patients continue to have neurological symptoms or retardation. 2/33 patients died during follow up (1 ischemic stroke from Pulmonary AVF, 1 death despite partial embolisation).Conclusion. Cerebral arteriovenous fistulae are a rare disease, but not infrequently seen in neonates and infants with AVMs. In one fourth of these patients HHT is suspected to be present. The AVFs are always superficial and fed by pial (cortical) arteries. They seldom reveal a hemorrhagic event. They are similar to those encountered in the posterior fossa or spinal cord. Endovascular treatment using NBCA was the treatment modality chosen resulting in a high rate of success and allowing children to grow up normally with no hemorrhages on follow up and no new symptom other than those already present on admission.


Acta Neurochirurgica | 2004

Angio-architecture of spinal cord arteriovenous shunts at presentation. Clinical correlations in adults and children

Georges Rodesch; M. Hurth; H. Alvarez; B. Ducot; M. Tadie; P. Lasjaunias

SummaryObjective. To analyse possible relationships between the symptoms and signs created by intradural spinal cord arteriovenous shunts (SCAVSs) and their angio-architecture. Methods. The clinical and radiological files of 155 patients, both adults and children, seen between 1981 and 1999 with a SCAVS were retrospectively reviewed. SCAVSs were divided into nidus type (small superficial or large intramedullary), and fistulas (micro (mAVFs)- or macrofistulas (MAVFs)). The angio-architectural points studied were arterial stenosis, proximal arterial aneurysm, distal arterial aneurysm, arteriovenous fistulas, pial venous drainage and/or reflux, venous ectasias, venous stenosis, venous thrombosis, false aneurysms. Correlations between architecture, location, age groups and symptoms and signs were made. Findings. A male predominance was noted in both adults and children. Most of the lesions were located at the thoracic level, but hemorrhage occured as the presenting event predominantly in cervical localizations. 30 patients (20 AVMs; 4 mAVFs, 6 MAVFs) were children. 5 of the 6 MAVFs found in children were associated with Hereditary Hemorrhagic Telengiectasia (HHT1). Twenty one children (70%) had bled. Spontaneous total or subtotal recovery was the rule in 15 of those who had bled (72%) but early recurrent hemorrhages occured in 2. Among 125 adults 56 presented with hemorrhage (45%). The proportions of those who recovered spontaneously (71%) or rebled (3,6%) in the same year after the initial episode were very similar to children. All other adults presented with acute or progressive non-hemorrhagic episodes. There was no significant difference in the angio-architecture between hemorrhagic and non hemorrhagic SCAVS, except for that occurrence of pseudo-aneurysms. Hemorrhage in SCAVSs may not be exclusively due to haemodynamic factors. Venous congestion was responsible for progressive symptoms. Acute deficits unrelated to bleeds were due to intralesional thrombosis or hemodynamic changes. Interpretation. The short term prognosis of hemorrhagic SCAVSs is good, and there is no need for emergency treatment. MRI delineates the cord and makes the diagnosis of the lesion but angiography remains the gold standard for analysis of the vasculature. The angio-architecture reflects the ageing of the lesion but there is not a precise correlation between angio-architecture and clinical symptoms, except for pseudoaneurysms which relate to the hemorrhagic portion of the lesion.


Interventional Neuroradiology | 2003

Dural Sinus Malformations (DSM) with Giant Lakes, in Neonates and Infants: Review of 30 Consecutive Cases

M. Barbosa; J. Mahadevan; Y. C. Weon; Y. Yoshida; Augustin Ozanne; G. Rodesch; H. Alvarez; P. Lasjaunias

Background and Purpose Dural Arteriovenous Shunt (DAVS) in children include Dural sinus malformation (DSM), infantile and adult types. They are rare and seldom reported. Our purpose was to highlight the angiographic features of the DSM sub group for prognosis of clinical evolution and outcome and to lay guidelines for management. Methods: From a dedicated neurovascular data bank, there were 52 cases of arteriovenous dural shunts in children from 1985 to 2003. Of these, there were 30 patients with DSM, which we analysed the various angioarchitecture, presentation and neurological outcome. Children clinical status was evaluated and scored at admission and follow up. Results There was an overall male dominance of 2:1. Antenatal diagnosis was obtained in 8/30 (26.7%) cases. Mean age of diagnosis was 5 months. Mean age at first consultation was 8.7 months. No patient was diagnosed during childhood. The most common clinical presentations were macrocrania 76.7%, seizures 23.3% and mental retardation 23.3%. In 14/30 (35.7%) of the patients, the therapeutic decision was to manage conservatively; in 5/14 (30.7%) with predictable favourable evolution and in 9/14 (64.3%) with irreversible poor neurological outcome. In the remaining 16/30 (53.3%) patients, endovascular treatment was performed. In 12/16 (75.0%) patients the neurological outcome was good, 3/16 (18.8%) patients had unfavourable evolution despite embolization. There was no morbidity mortality related to the procedures themselves. 1/16 (6.3%) patient was lost to follow-up. Overall 12/29 (45.8%) patients had an unfavourable neurological outcome with 11 patients dead and 1 with severe neurological deficit. In the surviving group of children, 17/18 (94.4%) have a good neurological outcome; in 10/18 (55.5%) the lesion is morphologically excluded. Conclusion DSM is rare disease with high mortality. They usually proceed to either total or partial spontaneous thrombosis before the age of 2 thus compromising normal cerebral venous drainage. DSM away from the torcular, good cavernous sinus, cavernous capture of sylvian veins, absence of pial veins, straight sinus or superior sagital sinus (SSS) reflux and absence of jugular bulb dys-maturation represent factors of good prognosis. Such patients will highly benefit for endovascular treatment. In partial endovascular approach the aim being is to separate the brain drainage from DSM drainage. This will be achieved by the transarterial approach to the associated mural arteriovenous shunts (AVS) and by disconnecting the pial reflux by transvenous route.


Acta Neurochirurgica | 2007

Management of spontaneous haemorrhagic intracranial vertebrobasilar dissection: review of 21 consecutive cases

W. Y. Zhao; Timo Krings; H. Alvarez; Augustin Ozanne; Staffan Holmin; P. Lasjaunias

SummaryIntroduction. Haemorrhagic intracranial vertebrobasilar dissection is an uncommon cause of nontraumatic subarachnoid haemorrhage (SAH) and accounts for only 1–10% of non-traumatic SAH. Treatment in the acute phase is considered to be essential because of the high risk of rebleeding and the consequent unfavourable outcome. However, the location, the potential for involvement of eloquent vessels and the histopathological characteristics of the vessel wall make treatment demanding from both a technical and anatomical point of view. We report our experience in the management of this disease.Patients and treatments. From 1989 to June 2006, we managed 21 patients with spontaneous haemorrhagic dissection located in the intracranial vertebrobasilar system, 13 patients were treated using an endovascular approach, 1 by surgical clipping, and 7 were managed conservatively.Results. Among the 13 patients treated endovascularly, 7 underwent proximal occlusion, 4 underwent parent artery embolization at the site of dissection, and 2 underwent endovascular trapping. Severe, treatment-related complications due to dislodgement of the thrombus during the procedure occurred in 1 patient, who then died from brainstem ischaemia. One patient died from severe pneumonia and one patient was left disabled from vasospastic ischaemia resulting from severe initial SAH. The remaining 10 patients had satisfactory outcomes: none rebled after treatment and when discharged they had Karnovsky scores of 80–100.Of the 7 conservatively treated patients, three died of rebleeding and four were discharged with Karnovsky scores of 50–100. One patient, who was treated surgically, was discharged with a Karnovsky of 90.Conclusion. The high rate of rebleeding and consequent mortality among the patients treated conservatively argues for treatment in the acute phase. Treatment should be guided by each patient’s angiomorphology, clinical condition and the experience of the neurosurgical/neuroradiological team. Options include endovascular or surgical trapping of the dissection and proximal occlusion and embolisation of the parent artery at the site of the dissection.


Acta Neurochirurgica | 2001

Intracranial Haemorrhage Within the First two Years of Life

D. Chul Suh; H. Alvarez; J. J. Bhattacharya; Georges Rodesch; P. Lasjaunias

Summary.Summary.Background: Spontaneous intracranial haemorrhage is not common in infants, with differences from adults in both aetiology and severity. The infantile CNS is more vulnerable because of incomplete hydrovenous maturation. We analyzed infantile intracranial haemorrhage mainly caused by structural brain lesions and discuss specific aetiologies with regard to haemodynamic characteristics.Subjects and Methods: We reviewed 20 infants less than 2 years of age from a total of 328 neonates and infants with intracranial vascular lesions seen in our institution since 1985. Associated or causative lesions were arteriovenous malformation (AVM) in 6, dural sinus malformation (DSM) in 4, arteriovenous fistula (AVF) in 3, aneurysm in 2, developmental venous anomaly (DVA) in 1, vein of Galen malformation (VGAM) in 1, and others in 3. The locations of haematomas were intracerebral (ICH) in 8, combined ICH and intraventricular haemorrhage (IVH) in 5, IVH alone in 5, subarachnoid haemorrhage (SAH) in 1, and combined SDH and ICH in 1.Findings: Three patterns of haemorrhage were noted in high-flow vascular lesions such as AVM or AVF (n=9); haemorrhage at the site of nidus or fistula corresponding to nidal pseudoaneurysm in 4, regional venous hypertension with pial venous reflux in 3, global venous infarction causing multifocal haemorrhage in distant brain areas in 2.Aneurysmal bleeds were caused by dissecting aneurysms at the level of dural penetration of cranial vessels. One infant had haemorrhage near a DVA without evidence of cavernous malformation suggesting the possibility of venous ischaemia. IVH was associated with shunt operations in 4 infants with DSM, and SDH followed by ICH in a infant with VGAM.Interpretation: Spontaneous intracranial haemorrhage in infants and neonates is rare; it is associated with specific lesions which show some differences from their adult counterparts. The vein-related causes of hemorrhage are largely the pathophysiologic characteristics in this age group. Absence of hemorrhage in VGAM is remarkable in addition to occurrence of most hemorrhages after shunting.


Acta Neurochirurgica | 2006

Multiple mirror-like intracranial aneurysms. Report of a case and review of the literature

C. E. Baccin; Timo Krings; H. Alvarez; Augustin Ozanne; P. Lasjaunias

SummaryWhile multiple intracranial arterial aneurysms occur in 26.4% of patients with aneurysms, in our practice bilateral mirror-like aneurysms are encountered in 9.4% of patients. Multiple mirror aneurysms in the same patient are exceedingly rare. We report a case of mirror-like middle cerebral artery aneurysms associated with mirror-like posterior inferior cerebellar arteries aneurysms and discuss their significance. Although an exceptional finding, multiple mirror-like aneurysms may shed light on the vulnerability of different arterial segments to specific diseases.


Acta Neurochirurgica | 2007

Segmental unfused basilar artery with kissing aneurysms: report of three cases and literature review

Timo Krings; C. E. Baccin; H. Alvarez; Augustin Ozanne; Paul Stracke; P. Lasjaunias

SummaryBasilar artery “fenestration” is the result of a failed fusion of the bilateral longitudinal neural arteries and can be associated with a saccular aneurysm, which typically arises at the proximal juncture of the unfused segment. “Kissing” aneurysms at this site, i.e. two aneurysms arising from the proximal junction of the unfused segment of the basilar artery pointing anteriorly and posteriorly are reported to be exceedingly rare. We present three patients with this rare condition, all of them being treated by endovascular techniques.


Interventional Neuroradiology | 1997

Embolisation of Spinal Cord Arteriovenous Malformations with Glue through the Anterior Spinal Axis: Review of 20 Cases

Georges Rodesch; Michel Hurth; H. Alvarez; P. Lasjaunias

We reviewed the clinical and morphological results of spinal cord arteriovenous malformations (SCAVMs) embolised with acrylic glue through the anterior spinal axis (ASA), and assessed the anatomical guidelines that should be followed to safely embolise the ASA. Twenty consecutive SCAVMS seen between 1982 and 1996 were reviewed. There were 15 lesions in the thoracolumbar cord and 5 in the cervical cord. Haemorrhage was the revealing symptom in 13 patients (65%). Embolisation through the ASA was done in 19 SCAVMs (2 with PVA particles in our early experience and 17 with Histoacryl*). One patient was not embolised because of a spastic reaction of the ASA that led to secondary subtotal thrombosis of the SCAVM without neurological deficit. The ASA was chosen as arterial approach to the AVM because it was the only feeder to the lesion (1 case) and/or because it was one of the accessible pedicles harbouring particular angioarchitectural weakness points. Vascular occlusion was always indicated and performed following precise anatomical analysis of the lesion and of the regional vascular disposition. In all cases embolisation of the ASA feeders to a SCAVM was performed under general anaesthesia, without any evoked potentials or provocative tests. However, 3/19 (16%) patients presented transient worsening of their clinical condition. Permanent morbidity occurred in 2/19 patients (11%): one patient cured from a cervical intramedullary AVM presents mainly a deltoid palsy, the other with a thoracic intramedullary AVM has worsened his paraparesis. At follow-up, 6/19 patients (32%) are neurologically normal and 10/19 (53%) have improved their neurological conditions and deficits. One patient embolised recently is currently stable but is expected to improve. No embolised patient bled or rebled during follow-up. Neurological symptoms recurred in one patient who had been stable for one year after his first embolisation. For an experienced interventional neuroradiology team, embolisation of SCAVMs through the ASA is feasible with acrylic glue with good clinical results. Proper analysis of the vascular architecture is mandatory to select the cases that can benefit from such approach.


Interventional Neuroradiology | 2004

Hereditary Haemorrhagic Telangiectasia Cerebrospinal Localization in Adults and Children. Review of 39 cases.

J. Mahadevan; Augustin Ozanne; Y. Yoshida; Yc Weon; H. Alvarez; G. Rodesch; P. Lasjaunias

Cerebral arteriovenous malformations (CAVM) can be associated with Hereditary Haemorrhagic Telangiectasia (HHT), adominantly inherited vascular disorder with variable penetrance and expressivity. The presentation and angiographic features were analysed retrospectively. The purpose is to point to special groups of AVM patients within the overall CAVMs and to discuss the issue of screening. We reviewed 34 cases of HHT -related CAVM from the data bank in Bicêtre from 1985–2003. In Spinal cor d AVM (SCAVM) there were 194 patients with 5 HHT. HHT was diagnosed when at least two criteria were met; cutaneous telangiectasia, epistaxis, visceral AVMs, angiographic findings of AVF and first degree family history. Intracranial haemorrhage was the presenting symptom in 8.8% and the risk of haemorrhage in the natural history was 0.7% per year. The commonest angiographic features in adults are nidus (81.8%) and multiplicity (45.5%), while in the paediatric group venous ectasia and giant pouches (91.3%), AVF (69.6%) and multiplicity (52.2%). In spinal cor d lesions macrofistulas are demonstrated in 83% of HHT with no multiplicity. HHT-related CAVMs present as multiple lesions, cortical in location, micro AVMs or AVF. HHT in SCAVM is expressed as single macro AVF, especially in the paediatric group. AVF in children are highly suggestive of HHT. We do not recommend screening in HHT adult patients for CAVM, while in the paediatric population, screening could be recommended at six months of age for cerebrospinal localization. These patients should be screened for Pulmonary AVF, which needs to be treated in priority.


Interventional Neuroradiology | 2002

Vascular Anomalies and the Risk of Multiple Aneurysms Development and Bleeding

M. Mazighi; P. Porter; Georges Rodesch; H. Alvarez; N. Aghakhani; P. Lasjaunias

The pathogenesis of aneurysmal subarachnoid hemorrhage is still debated and the prognosis remains severe, especially in multiple aneurysms, where the therapeutic management is complex. The aim of this study was to look for vascular anomalies and assess their relationship with aneurysm formation and bleeding in patients with multiple intracranial aneurysms. A prospective angiographical review was performed on 141 patients with multiple intracranial aneurysms seen from 1992 to 2000. Three hundred and fifty three aneurysms were studied. In 88% of the patients vascular anomalies were found. The most common were: asymmetric caudal basilar fusion (43.2%), variations of the anterior communicating artery (AcoA) complex (31.2%), symmetric caudal basilar fusion (26.2%), antero-inferior cerebellar artery-postero-inferior cerebellar artery (AICA-PICA) (15.6%), extradural origin of the PICA (10.6%), cavernous origin of the ophthalmic artery or dorsal ophthalmic artery (dOPH) (3.5%). Some aneurysm locations were associated with a high rate of vascular anomalies, e.g.: posterior cerebral aneurysm with asymmetric caudal fusion, AcoA aneurysm with AcoA complex variation, basilar tip aneurysm with extradural PICA or symmetric caudal fusion, PI CA aneurysm with AICA-PICA, para-ophthalmic aneurysm with dOPH. These aneurysm locations bled proportionally more frequently when associated with the related vascular anomaly. In conclusion, these results suggest that vascular anomalies are associated with aneurysm development and bleeding.

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Timo Krings

University Health Network

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Staffan Holmin

Karolinska University Hospital

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J. Mahadevan

University of Paris-Sud

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G. Rodesch

Free University of Berlin

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