Morphological evaluation of the distal medial striate artery. A study with cadaveric material / Evaluación morfológica de la arteria estriada medial distal. Un estudio con material cadavérico

Abstract Objective: To evaluate the morphology of the distal medial striated artery, taking into account biometric variables useful for clinical and surgical management. Methods: A descriptive transversal study was performed with a sample of brains, who underwent autopsy at the Institute of Legal Medicine and Forensic Sciences of Bucaramanga-Colombia, which were evaluated using the perfusion technique of vascular structures with polyester resin. Results: The distal medial striated artery was presented in 1.4% and 4.2% duplicated in the right and left hemispheres respectively. Agenesis was presented in 2.8% in the left hemisphere. Its origin was 44.6% of the anterior cerebral artery junction site with the anterior communicating artery and was observed in 6 cases (4.2%) presented with a common trunk with the orbitofrontal artery. The main qualitative finding was the sinuous trajectory that was observed in 57.7% on the right side and 45.1% in the left hemisphere. Also, an important alteration found at the biometric analysis was hypoplasia that could be related to the decreased blood supply to the basal nuclei. The diameter was 0.5 ± 0.2 mm and its total length was 20.3 ± 4.1 mm. Conclusions: The topographical knowledge of this structure determines the vulnerability of its morphology because it can complicate surgical procedures performed in the anterior segment of the arterial circle of the brain. Besides, the observed collateral circulation contributes to the blood supply and the perfect functionality of the subcortical nervous structures.

Resumen Objetivo: Evaluar la morfología de la arteria estriada medial distal, teniendo en cuenta variables biométricas útiles para el manejo clínico y quirúrgico. Métodos: Estudio descriptivo transversal con una muestra de cerebros que fueron sometidos a autopsia en el Instituto de Medicina Legal y Ciencias Forenses de Bucaramanga-Colombia, fueron evaluados mediante la técnica de perfusión de estructuras vasculares con resina de poliéster. Resultados: La arteria estriada medial distal se presentó en 1.4% y 4.2% duplicada en el hemisferio derecho e izquierdo respectivamente. Agenesia se presentó en 2.8% en el hemisferio izquierdo. Su origen fue 44.6% del sitio de unión de la arteria cerebral anterior con la arteria comunicante anterior y se observó en 6 casos (4.2%) que presentaban un tronco común con la arteria orbitofrontal. El hallazgo principal fue la trayectoria sinuosa que se observó en 57.7% en el lado derecho y 45.1% en el hemisferio izquierdo. También una alteración importante encontrada en el análisis biométrico fue la hipoplasia que podría estar relacionada con la disminución del suministro de sangre a los núcleos basales. El diámetro fue de 0.5 ±0.2 mm y su longitud total fue de 20.3 ±4.1 mm. Conclusiones: El conocimiento topográfico de esta estructura determina la vulnerabilidad de su morfología, porque puede complicar los procedimientos quirúrgicos realizados en el segmento anterior del círculo arterial del cerebro. Además, la circulación colateral observada contribuye al riego sanguíneo y al perfecto funcionamiento de las estructuras nerviosas subcorticales.

Anterior Cerebral Artery: An Anatomical Study

Introduction: Anterior cerebral artery (ACA), the smaller terminal branch of the internal carotid artery is significantclinically due to its wide variety of complexity and technical difficulty in surgical procedures.Methods and materials: This study was done in 50 embalmed adult brain hemispheres at Institute of Anatomy,Madras Medical College, Tamilnadu. The study of the anterior cerebral artery was undertaken to observe themode of origin, its course and branches.Results: Anterior cerebral artery originated from the internal carotid artery in 100% of specimens. ACA passedabove optic nerve in 32 specimens (64%), above optic chiasma in 16 specimens (32%) and above optic tract in 2specimens (4%). The average length of A1 segment of right ACA and left ACA were 14.3 mm and 13.7 mm respectively.The difference in diameter of 1mm or more on both sides was observed in 8%. Left A1 segment was duplicated in1 specimen (2%). Median artery of corpus callosum and Azygous anterior cerebral artery were found in onespecimen each. Fenestration of A2 segment was observed in one specimen (4%). Heubner’s artery arose from A2segment in 32 (64%) specimens, from A1 segment in 6 (12%) specimens and from the level of ACoA in 12 (24%)specimens. The orbitofrontal artery originated on an average distance of 5.73mm on right side and average of4.82mm on left side. Frontopolar artery(FPA) originated at a distance of about 20.2mm on right side and 17.6mmon left side. Callosomarginal artery and pericallosal artery were found in all the specimens. In one specimen theright FPA originated from callosomarginal artery.Conclusion: Rapidly advancing fields of vascular neurosurgery and interventional neuroradiology techniquesrequire a thorough understanding of the anatomy. This detailed study done under various parameters wouldbenefit the radiologists and neurosurgeons.

Bilateral Infarction of the Recurrent Arteries of Heubner Following Clipping of an Anterior Communicating Artery Aneurysm

A 50-year-old woman reported to the emergency department with thunderclap headache and vomiting. Non-enhanced brain computed tomography (CT) showed a subarachnoid hemorrhage of Hunt-Hess Grade II and Fisher Grade III. Brain angiography CT and transfemoral cerebral angiography (TFCA) revealed an aneurysm of the anterior communicating artery. A direct neck clipping was performed using the pterional approach. The post-operation CT was uneventful. Six days postoperatively, the patient became lethargic. The mean velocity (cm/s) of the middle cerebral artery peaked at 173 cm/s on the right side and 167 cm/s on the left. A TFCA revealed decreased perfusion in both recurrent arteries of Heubner (RAH), but no occlusion in either. Intra-arterial nimodipine injection was administered. On the 7th postoperative day, CT demonstrated a newly developed low-density lesion in the RAH territory bilaterally. The cause of the infarction was attributed to decreased perfusion caused by cerebral vasospasm. The patient was discharged with no definite neurologic deficit except for mild cognitive disorder.

Microsurgical anatomy of the Anterior Cerebral-anterior Communicating Artery

Several studies have described the anatomy of the anterior cerebral vascular complex involving the proximal anterior cerebral artery(A1), the anterior communicating artery, and the recurrent artery of Heubner. The anatomic data of these vessels with special reference to the cerebrovascular artery were reviewed. The unilateral hypoplasia of the proximal anterior cerebral artery and fenestration of the anterior communicating artery were most frequent vascular anomalies of each vessel which were associated with aneurysms of the anterior communicating artery.