Neurovascular relationship between abducens nerve and anterior inferior cerebellar artery

We aimed to study the neurovascular relationships between the anterior inferior cerebellar artery (AICA) and the abducens nerve to help determine the pathogenesis of abducens nerve palsy which can be caused by arterial compression. Twenty-two cadaveric brains (44 hemispheres) were investigated after injected of coloured latex in to the arterial system. The anterior inferior cerebellar artery originated as a single branch in 75%, duplicate in 22.7%, and triplicate in 2.3% of the hemispheres. Abducens nerves were located between the AICAs in all hemispheres when the AICA duplicated or triplicated. Additionally, we noted that the AICA or its main branches pierced the abducens nerve in five hemispheres (11.4%). The anatomy of the AICA and its relationship with the abducens nerve is very important for diagnosis and treatment

Colocação segura de pinos percutâneos em fraturas subcapitais do quinto metacarpo: um estudo anatômico Safe percutaneous pinning for subcapital fifth metacarpal fractures: an anatomical study

OBJETIVOS: Durante o tratamento de fraturas fechadas do colo do metacarpo do dedo mínimo (fraturas do boxeador) usando fixação percutânea com fio K transversal e outros procedimentos, pode ocorrer lesão iatrogênica do ramo digital dorsal do dedo mínimo (RDDDM) do ramo dorsal do nervo ulnar (RDNU). Neste estudo, visamos descrever a relação do RDDDM do RDNU e os pontos de inserção na face lateral do quinto metacarpo durante fixação percutânea com fio K transversal de fraturas subcapitais. MÉTODOS: Foram realizadas dissecações e medições desse ramo depois de colocação de pino transversal percutâneo na parte distal do quinto osso do metacarpo em dez mãos de cadáveres fixadas em formalina. RESULTADOS: Os resultados desse estudo confirmam a grande proximidade da trajetória do pino e desse ramo, e demonstram sua possível lesão iatrogênica durante a fixação do fio K no quinto metacarpo. CONCLUSÕES: Para evitar a penetração desse nervo e limitar as chances de lesão iatrogênica, é importante conhecer o trajeto desse nervo. Os autores descrevem os pontos de inserção anatômica e acreditam que com uso do conhecimento da anatomia das fraturas subcapitais do quinto metacarpo, elas podem ser tratadas sem risco de déficits sensoriais futuros.OBJECTIVES: When treating closed fractures of the neck of the little finger metacarpal (boxer fractures) with percutaneous transverse K-wire fixation and other procedures, there may be iatrogenic injury to the dorsal digital branch to the little finger (DDBLF) of the dorsal branch of the ulnar nerve (DBUN . In this study we aimed to describe the relationship of the DDBLF of the DBUN and the insertion points on the external side of the fifth metacarpal during percutaneous transverse K-wire fixation of subcapital fractures. METHODS: Dissections and measurements regarding this branch were performed after percutaneous transverse pinning to distal part of fifth metacarpal bones in ten cadaver hands formalin fixed. RESULTS: The results of this study confirm the close proximity of the trajectory of the with this branch and demonstrate its potential iatrogenic injury during K-wire fixation of the fifth metacarpal. CONCLUSIONS: To avoid penetration of this nerve and limit the chances of iatrogenic injury it is important to know its course. The authors describe the anatomical insertion points and believe that using the anatomical knowledge, subcapital fifth metacarpal fractures can be treated without risk of sensory deficits