Flow diversion for the treatment of posterior inferior cerebellar artery aneurysms: a novel classification and strategies.

BACKGROUND: The pipeline embolization device (PED) is frequently used in the treatment of anterior circulation aneurysms, especially around the carotid siphon, with generally excellent results. However, treatment of posterior inferior cerebellar artery (PICA) aneurysms with flow diversion (FD) has not been specifically described or discussed. While there are reports of treating PICA aneurysms using placement of FD stents in the vertebral artery, there are no reports of treating these lesions by placement of flow diverting stents in the PICA vessel itself. Due to the unique anatomy and morphology of these aneurysms, it requires special attention. We assessed our multi-institutional experience treating these lesions, including the first reported cases of the PED placed within the PICA. METHODS: Institutional databases of neuroendovascular procedures were reviewed for cases of intracranial aneurysms treated with the PED. Patient and aneurysm data as well as angiographic imaging were reviewed for all cases of PICA aneurysms treated with the PED. PICA aneurysms were defined as aneurysms that involved the PICA. Vertebral aneurysms without disease in the PICA were excluded from the study. RESULTS: 10 PICA aneurysms were treated during the study period. These were classified based on their morphology and location into two main types and five total subtypes for consideration of treatment with flow diversion. All aneurysms were successfully treated, with 8/10 completely obliterated and 2 with a partial reduction in size. Three patients had the PED placed entirely in the PICA and no patient suffered from a medullary or cerebellar stroke. All PEDs were patent and all patients were independent at the last follow-up. CONCLUSIONS: The PED may be used successfully to treat select aneurysms of the PICA. We present the first described cases of successful PED treatment of PICA aneurysms with direct placement of the PED in the PICA vessel itself. The proposed classification system aids in that selection.

A pilot study and novel angiographic classification for superior sagittal sinus stenting in patients with non-thrombotic intracranial venous occlusive disease.

OBJECTIVE: Safety and efficacy of superior sagittal sinus (SSS) stenting for non-thrombotic intracranial venous occlusive disease (VOD) is unknown. The aim of this retrospective cohort study is to evaluate outcomes after SSS stenting. METHODS: We evaluated an institutional database to identify patients who underwent SSS stenting. Radiographic and clinical outcomes were analyzed and a novel angiographic classification of the SSS was proposed. RESULTS: We identified 19 patients; 42% developed SSS stenosis after transverse sinus stenting. Pre-stent maximum mean venous pressure (MVP) in the SSS of 16.2 mm Hg decreased to 13.1 mm Hg after stenting (p=0.037). Preoperative trans-stenosis pressure gradient of 4.2 mm Hg decreased to 1.5 mm Hg after stenting (p<0.001). No intraprocedural complication or junctional SSS stenosis distal to the stent construct was noted. Improvement in headache, tinnitus, and visual obscurations was reported by 66.7%, 63.6%, and 50% of affected patients, respectively, at mean follow-up of 5.2 months. We divided the SSS into four anatomically equal segments, numbered S1-S4, from the torcula to frontal pole. SSS stenosis typically occurs in the S1 segment, and the anterior extent of SSS stents was deployed at the S1-S2 junction in all but one case. CONCLUSIONS: SSS stenting is reasonably safe, may improve clinical symptoms, and significantly reduces maximum MVP and trans-stenosis pressure gradients in patients with VOD with SSS stenosis. The S1 segment is most commonly stenotic, and minimum pressure gradients for symptomatic SSS stenosis may be lower than for transverse or sigmoid stenosis. Additional studies and follow-up are necessary to better elucidate appropriate clinical indications and long-term efficacy of SSS stenting.

Proposition of a new classification of the cerebral veins based on their termination.

The existing classifications of cerebral veins have certain problems, including limited adequacy to uniquely describe neurovascular networks in three dimensions (3D), mixture of deep and superficial veins, and ambiguity of territories-based parcellations as veins may course on multiple territories. Classification discrepancies exist in subdivision, region drained, and parcellation criteria. Recent developments in diagnostic imaging and computers enable to acquire, create, and manipulate complete vascular networks, which also call for a new classification of cerebral veins. We propose a new classification suitable for the description of the complete cerebral veins, providing a clear separation of the superficial cortical veins from deep veins, and facilitating presentation and exploration of cerebral veins in 3D with respect to surrounding neuroanatomy. It is based on terminating vascular subsystems (rather than draining regions). It divides the cerebral veins into cortical, deep, and posterior fossa veins. The cortical veins are subdivided into two groups: terminating in dural sinuses and terminating in deep veins. The posterior fossa veins are subdivided also into two groups: terminating in dural sinuses and terminating in deep veins. This classification was illustrated with a cerebrovascular model containing over 1,300 vessels. This new classification has many advantages. It is simple, clear and didactically useful; avoids mixture of superficial and deep veins; shows overall hierarchical structure and topographical relationships including tributaries; is useful in analysis of 3D vascular trees extracted from imaging; and may be used in conjunction with the existing parcellations.

Malformación de la vena de Galeno / Vein of Galen malformation

Objetivo: describir y analizar la embriología, anatomía, angioarquitectura y clínica de la malformación de la vena de Galeno. Método: revisión bibliográfica con actualización del tema. Resultados: la malformación de la vena de Galeno es una anormalidad congénita que presenta el 30% de las lesiones vasculares en los pacientes pediátricos. Se caracteriza por la persistencia de una vena embrionaria: la vena prosencefálica media, asociada a shunts arteriales por persistencia de una conexión fistulosa con arterias coroideas primitivas. La vena de Galeno se localiza en la región pineal, dentro de la cisterna cuadrigeminal. Se forma por la unión de las venas cerebrales internas y cursa posteriormente drenando hacia el seno recto. Su longitud varía de 3,1 a 25 mm. Las malformaciones de la vena de Galeno se clasifican en 1)malformación aneurismática verdadera y 2) dilatación aneurismática. Basándose en la angioarquitectura el primer tipo se divide en 2 formas: mural y coroidea. La presentación clínica es variada y depende del tipo. El diagnóstico prenatal es posible con la ecografía y la resonancia magnética. El diagnóstico definitivo se logra con la angiografía digital. El éxito del tratamiento depende del reconocimiento de sus tipos y formas y, de un adecuado equipo de especialistas. Conclusión: el conocimiento de la embriología, anatomía y, tipos y formas de la malformación de la vena de Galeno, aseguran el éxito del diagnóstico y tratamiento. Palabras clave: angioarquitectura, clasificación, malformación de la vena de Galeno(AU)

Objective: to describe and analyse the embryology, anatomy, angioarchitecture and clinical presentation of the vein of Galen malformation. Method: biblographic review up to date. Results: the vein of Galen malformation is a congenital anomaly that represents 30% of all the vascular lesions in the pediatric population. It is secondary to the persistence of an embrionary vein: the medial prosencephalic vein, associated with arterial shunts secondary to the persistence of a fistulous connection with the coroideal primitive arteries. The vein of Galen is localized at the pineal region, within the cuadrigeminal cistern. It is formed by the union of both internal cerebral veins and drains posteriorly into strait sinus. it has a length of 3.1 to 25 mm. They are classified in: 1) truth aneurismal malformation and 2) aneurismal dilatation. Based on its angioarchitecture the first type is divided into 2 forms: mural and coroidal. The clinical presentation is variable and depends on the type. Prenatal diagnosis is possible with ecography and magnetic resonance. Definitive diagnosis is performed with digital angiography. A successful treatment depends on the recognition of the different types and forms and on the presence of an appropriate team of specialists. Conclusion: the knowledge of the embryology, anatomyand types and forms of the vein of Galen malformation assure the success of its diagnosis and treatment. Key words: angioarchitecture, classification, vein of Galen malformation.(AU)

Malformación de la vena de Galeno / Vein of Galen malformation

Objetivo: describir y analizar la embriología, anatomía, angioarquitectura y clínica de la malformación de la vena de Galeno. Método: revisión bibliográfica con actualización del tema. Resultados: la malformación de la vena de Galeno es una anormalidad congénita que presenta el 30% de las lesiones vasculares en los pacientes pediátricos. Se caracteriza por la persistencia de una vena embrionaria: la vena prosencefálica media, asociada a shunts arteriales por persistencia de una conexión fistulosa con arterias coroideas primitivas. La vena de Galeno se localiza en la región pineal, dentro de la cisterna cuadrigeminal. Se forma por la unión de las venas cerebrales internas y cursa posteriormente drenando hacia el seno recto. Su longitud varía de 3,1 a 25 mm. Las malformaciones de la vena de Galeno se clasifican en 1)malformación aneurismática verdadera y 2) dilatación aneurismática. Basándose en la angioarquitectura el primer tipo se divide en 2 formas: mural y coroidea. La presentación clínica es variada y depende del tipo. El diagnóstico prenatal es posible con la ecografía y la resonancia magnética. El diagnóstico definitivo se logra con la angiografía digital. El éxito del tratamiento depende del reconocimiento de sus tipos y formas y, de un adecuado equipo de especialistas. Conclusión: el conocimiento de la embriología, anatomía y, tipos y formas de la malformación de la vena de Galeno, aseguran el éxito del diagnóstico y tratamiento. Palabras clave: angioarquitectura, clasificación, malformación de la vena de Galeno(AU)

Objective: to describe and analyse the embryology, anatomy, angioarchitecture and clinical presentation of the vein of Galen malformation. Method: biblographic review up to date. Results: the vein of Galen malformation is a congenital anomaly that represents 30% of all the vascular lesions in the pediatric population. It is secondary to the persistence of an embrionary vein: the medial prosencephalic vein, associated with arterial shunts secondary to the persistence of a fistulous connection with the coroideal primitive arteries. The vein of Galen is localized at the pineal region, within the cuadrigeminal cistern. It is formed by the union of both internal cerebral veins and drains posteriorly into strait sinus. it has a length of 3.1 to 25 mm. They are classified in: 1) truth aneurismal malformation and 2) aneurismal dilatation. Based on its angioarchitecture the first type is divided into 2 forms: mural and coroidal. The clinical presentation is variable and depends on the type. Prenatal diagnosis is possible with ecography and magnetic resonance. Definitive diagnosis is performed with digital angiography. A successful treatment depends on the recognition of the different types and forms and on the presence of an appropriate team of specialists. Conclusion: the knowledge of the embryology, anatomyand types and forms of the vein of Galen malformation assure the success of its diagnosis and treatment. Key words: angioarchitecture, classification, vein of Galen malformation.(AU)

Malformación de la vena de Galeno / Vein of Galen malformation

Objetivo: describir y analizar la embriología, anatomía, angioarquitectura y clínica de la malformación de la vena de Galeno. Método: revisión bibliográfica con actualización del tema. Resultados: la malformación de la vena de Galeno es una anormalidad congénita que presenta el 30% de las lesiones vasculares en los pacientes pediátricos. Se caracteriza por la persistencia de una vena embrionaria: la vena prosencefálica media, asociada a shunts arteriales por persistencia de una conexión fistulosa con arterias coroideas primitivas. La vena de Galeno se localiza en la región pineal, dentro de la cisterna cuadrigeminal. Se forma por la unión de las venas cerebrales internas y cursa posteriormente drenando hacia el seno recto. Su longitud varía de 3,1 a 25 mm. Las malformaciones de la vena de Galeno se clasifican en 1)malformación aneurismática verdadera y 2) dilatación aneurismática. Basándose en la angioarquitectura el primer tipo se divide en 2 formas: mural y coroidea. La presentación clínica es variada y depende del tipo. El diagnóstico prenatal es posible con la ecografía y la resonancia magnética. El diagnóstico definitivo se logra con la angiografía digital. El éxito del tratamiento depende del reconocimiento de sus tipos y formas y, de un adecuado equipo de especialistas. Conclusión: el conocimiento de la embriología, anatomía y, tipos y formas de la malformación de la vena de Galeno, aseguran el éxito del diagnóstico y tratamiento. Palabras clave: angioarquitectura, clasificación, malformación de la vena de Galeno

Objective: to describe and analyse the embryology, anatomy, angioarchitecture and clinical presentation of the vein of Galen malformation. Method: biblographic review up to date. Results: the vein of Galen malformation is a congenital anomaly that represents 30% of all the vascular lesions in the pediatric population. It is secondary to the persistence of an embrionary vein: the medial prosencephalic vein, associated with arterial shunts secondary to the persistence of a fistulous connection with the coroideal primitive arteries. The vein of Galen is localized at the pineal region, within the cuadrigeminal cistern. It is formed by the union of both internal cerebral veins and drains posteriorly into strait sinus. it has a length of 3.1 to 25 mm. They are classified in: 1) truth aneurismal malformation and 2) aneurismal dilatation. Based on its angioarchitecture the first type is divided into 2 forms: mural and coroidal. The clinical presentation is variable and depends on the type. Prenatal diagnosis is possible with ecography and magnetic resonance. Definitive diagnosis is performed with digital angiography. A successful treatment depends on the recognition of the different types and forms and on the presence of an appropriate team of specialists. Conclusion: the knowledge of the embryology, anatomyand types and forms of the vein of Galen malformation assure the success of its diagnosis and treatment. Key words: angioarchitecture, classification, vein of Galen malformation.

A proposed angiographic classification of intracranial arteriovenous fistulae and malformations.

We propose an angioarchitectural classification of intracranial vascular lesions as arteriovenous, arteriolovenous and arteriolovenulous fistulae. In order to validate this classification, 99 intracranial arteriovenous lesions were reviewed in 98 patients. Arteriolovenulous fistulae included 39 isolated brain arteriovenous malformations (AVMs) and 1 AVM associated with a giant arteriovenous fistula (AVF). Arteriovenous fistulae included 8 giant AVFs of the brain, 6 vein of Galen aneurysms and 10 direct caroticocavernous fistulae. Arteriolovenous fistulae included 1 isolated brain AVM, 4 vein of Galen aneurysms and 30 dural AVMs. The angioarchitectural classification has three advantages. It is simple and accurate, with no reference to the congenital or acquired nature of the lesion. It allows separate identification of a special group, the arteriolovenous fistulae. It also indicates the endovascular approach: arteriolovenulous fistulae should be treated via the arterial route only, while arteriovenous and arteriolovenous fistulae can be treated via transarterial or transvenous approaches.