RESUMEN
OBJECTIVE: The superior ophthalmic vein (SOV) provides an alternative venous access for the treatment of carotid-cavernous fistulae. Its direct surgical exposure and cannulation can be difficult. This study was performed to identify anatomic landmarks to facilitate localization and exposure of the SOV. METHODS: The vascular tree of 6 formalin-fixed human cadaveric heads was injected with colored silicone. The SOV was exposed using a periorbital incision. The diameter of the SOV, its distance to the inferior border of the incision, and the angle formed by the SOV and sagittal midpupillary line were measured. The tributaries of the SOV and its orbital anatomy and relationship to the supraorbital notch/foramen were evaluated. RESULTS: The SOV was located in the superomedial quadrant of the orbit. Its mean diameter was 2.2 mm (standard deviation, +/-1.2 mm). The mean distance from the SOV to the superior sulcus of the eyelid nasally was 5.9 mm (standard deviation, +/-2.0 mm). The mean angle formed by the SOV and the sagittal midpupillary line was 27.9 degrees (standard deviation, +/-5.4 degrees). The tributaries of the SOV were the angular vein and supraorbital vein (SPOV). The SPOV, identified in all 12 dissections, could be followed to the SOV within the orbit. The SPOV was always located inside the supraorbital notch/foramen when the latter was present. CONCLUSION: The SOV is located at the superomedial quadrant of the orbit. The SPOV is a reliable reference during surgical exposure. A lid crease or subbrow incision centered over the supraorbital notch simplifies identification of the SOV.
Asunto(s)
Seno Cavernoso/cirugía , Malformaciones Arteriovenosas Intracraneales/cirugía , Órbita/irrigación sanguínea , Órbita/cirugía , Vena Retiniana/cirugía , Procedimientos Quirúrgicos Vasculares/métodos , Anciano , Anciano de 80 o más Años , Cadáver , Seno Cavernoso/anomalías , Seno Cavernoso/patología , Malformaciones Vasculares del Sistema Nervioso Central/diagnóstico por imagen , Malformaciones Vasculares del Sistema Nervioso Central/patología , Malformaciones Vasculares del Sistema Nervioso Central/cirugía , Disección/métodos , Embolización Terapéutica/instrumentación , Embolización Terapéutica/métodos , Párpados/anatomía & histología , Párpados/cirugía , Femenino , Humanos , Malformaciones Arteriovenosas Intracraneales/diagnóstico por imagen , Malformaciones Arteriovenosas Intracraneales/patología , Complicaciones Intraoperatorias/prevención & control , Masculino , Persona de Mediana Edad , Procedimientos Quirúrgicos Oftalmológicos/métodos , Cuidados Preoperatorios/métodos , Prótesis e Implantes , Radiografía , Vena Retiniana/anatomía & histología , Siliconas , Coloración y Etiquetado , Resultado del TratamientoRESUMEN
OBJECTIVE: An accessory middle cerebral artery (MCA) usually originates between the A1 and proximal A2 segment of the anterior cerebral artery, reaches the sylvian fissure, and supplies the territory of the MCA. This anomaly has been associated with cerebral aneurysms and Moyamoya disease. We report an accessory MCA arising from the A2 segment. METHODS: A cadaveric head, fixed in formalin solution and injected with red and blue silicone on its vascular tree to trace intracranial and extracranial vessels, was dissected. RESULTS: An accessory MCA was found arising from the A2 segment of the anterior cerebral artery and feeding the basal and inferior surface of the inferior frontal gyrus. In our specimen, the vessel was associated with intracranial aneurysms at other locations. CONCLUSION: Although anomalies of the MCA are rare, neurosurgeons must be familiar with such anatomic variations. An accessory MCA can be associated with Moyamoya disease and aneurysms at its junction with the anterior cerebral artery. Patients with this anomaly may, therefore, have an increased risk for developing aneurysms and other neurovascular complications. By obstructing the surgical view, an accessory MCA may increase the difficulty of exposing lesions in the vicinity of the optic chiasm.
Asunto(s)
Encéfalo/irrigación sanguínea , Arteria Cerebral Media/anomalías , Arteria Cerebral Media/anatomía & histología , Encéfalo/cirugía , Angiografía Cerebral/métodos , Humanos , Arteria Cerebral Media/cirugía , Procedimientos Neuroquirúrgicos/métodosRESUMEN
OBJECTIVE: In many locations, neurosurgeons still use stereotactic- or anatomic-based craniocerebral topography systems to identify cortical landmarks. However, their predictive value for identifying two key landmarks--the central sulcus (CS) and lateral sulcus (LS)--has never been evaluated. We quantitatively compare leading craniocerebral topographic methods and review their historical significance for neurosurgery. METHODS: On 12 cadaveric head sides, the methods of Broca, Reid, Poirier, Taylor-Haughton, and Rhoton were used to predict positions of the CS and LS. After craniotomy, the actual CS, LS, and the superior and inferior Rolandic points were identified. Distances between predicted positions and actual structures were measured, and the systems were compared. RESULTS: The actual superior Rolandic point was 4.6 +/- 2.9 mm anterior to prediction by Broca's method; 4.3 +/- 2.13 mm anterior to the Poirier, Taylor-Haughton, and Rhoton methods; and 3.26 +/- 3.17 mm anterior or posterior using Reid's method. The actual inferior Rolandic point was anteroinferior to all predictions: 5.87 +/- 3.1 mm by Rhoton, 6.97 +/- 3.55 mm by Broca, 7.64 +/- 2.54 mm by Poirier, and 7.61 +/- 3.85 mm by Reid and Taylor-Haughton. The actual LS was 2.33 mm away from the predicted point using Poirier's method, and 2.00 mm away from the predicted point using the Reid, Taylor-Haughton, and Rhoton methods. CONCLUSION: Predicting positions of the CS and LS to within a few millimeters, these landmark methods remain reliable for cerebral localization. Largely initiated by the work of Paul Broca, these systems lay at the development of a practical method of neurosurgery in the late 19th century.
Asunto(s)
Anatomía/historia , Biometría/historia , Biometría/métodos , Encéfalo/anatomía & histología , Historia del Siglo XIX , Historia del Siglo XX , Humanos , Ilustración MédicaRESUMEN
OBJECTIVE: The superficial venous system of the posterior neck (suboccipital venous plexus) is a potential source of complications from bleeding and air embolism. Because there is little information available about this in the literature, an anatomic study of the superficial posterior neck venous system and a morphometric analysis of the mastoid emissary vein (MEV) complex were undertaken. Both surgical and endovascular implications were considered. METHODS: The posterior craniocervical regions of 15 silicon-injected human cadaveric specimens were dissected. The patterns and variances of venous anatomy were observed. Distances between fixed bony landmarks were measured with a caliper. RESULTS: The suboccipital venous plexus, which forms a complex venous network located between the posterior muscular layers of the neck, drains to the anterior vertebral vein and deep cervical vein. The MEV connects this plexus to the sigmoid sinus. Its average diameter was 2.15 mm, and it was located a mean of 21.14 mm from the asterion and a mean of 33.65 mm from the mastoid tip. However, the size of the MEV complex varied considerably. CONCLUSION: The suboccipital venous plexus in the posterior neck region may be very large. The size of the veins in the plexus varies, but the drainage pattern remains consistent. The plexus is a potential source of intense bleeding and air embolism during posterior fossa approaches. The risks are greatest for lateral surgical approaches, as a result of the anatomic position of the venous system. The described measurements can be used to approach the MEV in endovascular procedures that involve the sigmoid sinus.
Asunto(s)
Venas Cerebrales/anatomía & histología , Venas Cerebrales/cirugía , Cuello , Procedimientos Neuroquirúrgicos/métodos , Seno Sagital Superior/anatomía & histología , Seno Sagital Superior/cirugía , Cadáver , Cabeza , HumanosRESUMEN
Almost 50 years of research on moyamoya disease (1957-2006) has led to the development of a variety of surgical and medical options for its management in affected patients. Some of these options have been abandoned, others have served as the basis for the development of better procedures, and many are still in use today. Investigators studying moyamoya disease during this period have concluded that the best treatment is planned after studying each patient's presenting symptoms and angiographic pattern. The surgical procedures proposed for the treatment of moyamoya disease can be classified into three categories: direct arterial bypasses, indirect arterial bypasses, and other methods. Direct bypass methods that have been proposed are vein grafts and extracranial-intracranial anastomosis (superficial temporal artery-middle cerebral artery [STA-MCA] anastomosis and occipital artery-MCA anastomosis). Indirect techniques that have been proposed are the following: 1) encephaloduroarteriosynangiosis; 2) encephalomyosynangiosis; 3) encephalomyoarteriosynangiosis; 4) multiple cranial bur holes; and 5) transplantation of omentum. Other options such as cervical carotid sympathectomy and superior cervical ganglionectomy have also been proposed. In this paper the authors describe the history of the development of surgical techniques for treating moyamoya disease.