Acesso supratentorial-infraoccipital ou occipitopolar: estudo clínico e anatômico Supratentorial-infraoccipital (or occipitopolar) approach: clinical and anatomical study

Realizou-se análise de 22 pacientes portadores de tumores e lesões vasculares (malformações arteriovenosas e aneurismas) das regiões posteriores do giro parahipocampal e do pulvinar do tálamo e operados pelo acesso supratentorial-infraoccipital. Em quinze pacientes com tumor, a ressecção foi completa em seis e parcial em nove. Os cinco pacientes com malformação arteriovenosa foram submetidos a exérese total da lesão. Realizou-se também o estudo anatômico deste acesso em cinco segmentos cefálicos (dez lados). Os resultados cirúrgicos e do estudo anatômico sugerem que o acesso supratentorial-infraoccipital representa opção para abordar lesões do pulvinar do tálamo e do lobo temporal posteromedial que afloram na fissura transversa do cérebro.<br>Twenty-two patients harboring tumors or vascular lesions (AVMs and aneurysms) located at the posterior aspect of the parahipocampal gyrus and the pulvinar of thalamus operated by supratentorial-infraoccipital approach were analysed. Total resection was achieved in all five AVM patients as well as in six out of fifteen tumor patients. This approach was performed in five anatomical specimens (ten approaches); It results, along with the surgical results, allow this approach to be considered a good option for lesions of the pulvinar of thalamus and postero-medial temporal lobe which are evident at the transverse fissure

Occipital bi-transtentorial/falcine approach for falcotentorial meningioma: case report Acesso occipital bitranstentorial-falcino para abordagem de meningioma falco-tentorial: relato de caso

Lesions located in the bilateral posterior incisural space are difficult to treat due to limited exposure. The classical approaches to this area are limited for lesions located bilaterally and especially when the lesion extends also below the tentorium as it may occur with meningiomas. Kawashima et al. reported, in anatomic studies, a new occipital transtentorial approach: the occipital bi-transtentorial/falcine approach, to treat such lesions. We present a patient with a large falcotentorial meningioma, located bilaterally in the posterior incisural space. The occipital bi-transtentorial/falcine approach allowed an excellent surgical exposure and complete tumor removal with an excellent patient outcome.<br>Grandes lesões que ocupam bilateralmente o espaço incisural posterior são de difícil abordagem cirúrgica pelos acessos clássicos. Recentemente, Kawashima et al. descreveram, em peças anatômicas, uma modificação do acesso occipital transtentorial, o acesso occipital bitranstentorial-falcino, para abordagem de grandes lesões que ocupam bilateralmente o espaço incisural posterior. Retata-se um caso de grande meningioma falco-tentorial que ocupava o espaço incisural posterior bilateralmente. O acesso occipital bitranstentorial-falcino permitiu exérese completa da lesão sem déficit no pós-operatório

Human Placenta Aneurysm Model for Training Neurosurgeons in Vascular Microsurgery

BACKGROUND: Neurosurgery, a demanding specialty, involves many microsurgical procedures that require complex skills, including open surgical treatment of intracranial aneurysms. Simulation or practice models may be useful for acquiring these skills before trainees perform surgery on human patients. OBJECTIVE: To describe a human placenta model for the creation and clipping of aneurysms. METHODS: Placental vessels from 40 human placentas that were dimensionally comparable to the sizes of appropriate cerebral vessels were isolated to create aneurysms of different shapes. The placentas were then prepared for vascular microsurgery exercises. Sylvian fissure-like dissection technique and clipping of large- and small-necked aneurysms were practiced on human placentas with and without pulsatile flow. A surgical field designed to resemble a real craniotomy was reproduced in the model. RESULTS: The human placenta has a plethora of vessels that are of the proper dimensions to allow the creation of aneurysms with dome and neck dimensions similar to those of human saccular and fusiform cerebral aneurysms. These anatomic scenarios allowed aneurysm inspection, manipulation, and clipping practice. Technical microsurgical procedures include simulation of sylvian fissure dissection, unruptured aneurysm clipping, ruptured aneurysm clipping, and wrapping; all were reproduced with high fidelity to the haptics of live human surgery. Skill-training exercises realistically reproduced aneurysm clipping. CONCLUSION: Human placenta provides an inexpensive, widely available, convenient biological tissue that can be used to create models of cerebral aneurysms of different morphologies. Neurosurgical trainees may benefit from the preoperative use of a realistic model to gain familiarity and practice with critical surgical techniques for treating aneurysms