Optic Tract as an Upper Limit in Amygdalectomy: Microsurgical Study.

BACKGROUND: In surgeries involving resection of the amygdala, despite clear relations established with the medial, lateral, anterior, posterior, and inferior segments, the upper limit remains controversial. The optic tract (OT) has been anatomically considered as a good landmark immediately inferior to the striatopallidal region. This anatomic structure has barely been explored by microsurgical study, generating uncertainty about the exact relationship with the surrounding structures. OBJECTIVE: To describe the OT in its entire length through microsurgical study, showing its superior, inferior, medial, and lateral relationships and highlighting its value as a landmark in superior amygdala resection. METHODS: Microsurgical anatomic dissection of the OT, from its origin in the chiasm to the lateral geniculate nucleus was performed in 8 alcohol-fixed human hemispheres, showing its different segments and relations. Photographs were taken from different angles to facilitate surgical orientation. RESULTS: We performed a dissection of the OT, showing its position relative to caudate and hippocampal formations. We exposed the structures related to the OT superiorly (striatopallidal region and superior caudate fasciculus), inferiorly (head of the hippocampus, amygdala, anterior choroidal artery, perforating artery branch of the anterior choroidal artery, terminal stria, and basal vein), medially (internal capsule and midbrain), and laterally (temporal stem [uncinate and inferior fronto-occipital fascicle], anterior perforated substance, and superior caudate fasciculus). CONCLUSION: To date, there is a paucity of articles describing the anatomy of the OT from a neurosurgery perspective. In this study, we describe the microsurgical anatomic path of the OT, as a reliable upper limit landmark for amygdala resection.

Metástasis espinal por carcinoma de células de Merkel en paciente inmunodeprimido: caso clínico / Merkel cell carcinoma spinal metastases in an immunosuppressed patient: Clinical case

El carcinoma de células de Merkel es un tumor cutáneo maligno poco frecuente, originado a partir de las células neuroendocrinas de la epidermis, denominadas células de Merkel. Presenta un pronóstico infausto cuando la enfermedad es diseminada. Dentro de las metástasis a distancia, la localización espinal es muy poco frecuente y no existe un consenso en cuanto a su manejo. Presentamos el segundo caso descrito en la literatura hasta el momento de afectación metastásica espinal por carcinoma de células de Merkel en paciente inmunodeprimido (AU)

Merkel cell carcinoma is a rare epidermal malignant tumor arised from neuroendocrine epidermal cells, called Merkel cells. Prognosis is poor when tumor spreads to distant locations. Among metastases sites, spinal is not frequent at all and its management remains controversial. We present the second reported case of spinal metastases from Merkel cell carcinoma in an immunosuppressed patient (AU)

Merkel cell carcinoma spinal metastases in an immunosuppressed patient: Clinical case. / Metástasis espinal por carcinoma de células de Merkel en paciente inmunodeprimido: caso clínico.

Merkel cell carcinoma is a rare epidermal malignant tumor arised from neuroendocrine epidermal cells, called Merkel cells. Prognosis is poor when tumor spreads to distant locations. Among metastases sites, spinal is not frequent at all and its management remains controversial. We present the second reported case of spinal metastases from Merkel cell carcinoma in an immunosuppressed patient.

Novel Simulation Model with Pulsatile Flow System for Microvascular Training, Research, and Improving Patient Surgical Outcomes.

BACKGROUND: Simulation allows surgical trainees to acquire surgical skills in a safe environment. With the aim of reducing the use of animal experimentation, different alternative nonliving models have been pursued. However, one of the main disadvantages of these nonliving models has been the absence of arterial flow, pulsation, and the ability to integrate both during a procedure on a blood vessel. In the present report, we have introduced a microvascular surgery simulation training model that uses a fiscally responsible and replicable pulsatile flow system. METHODS: We connected 30 human placentas to a pulsatile flow system and used them to simulate aneurysm clipping and vascular anastomosis. RESULTS: The presence of the pulsatile flow system allowed for the simulation of a hydrodynamic mechanism similar to that found in real life. In the aneurysm simulation, the arterial flow could be evaluated before and after clipping the aneurysm using a Doppler ultrasound system. When practicing anastomosis, the use of the pulsatile flow system allowed us to assess the vascular flow through the anastomosis, with verification using the Doppler ultrasound system. Leaks were manifested as "blood" pulsatile ejections and were more frequent at the beginning of the surgical practice, showing a learning curve. CONCLUSIONS: We have provided a step-by-step guide for the assembly of a replicable and inexpensive pulsatile flow system and its use in placentas for the simulation of, and training in, performing different types of anastomoses and intracranial aneurysms surgery.