An initial experience with intraoperative O-Arm for deep brain stimulation surgery: can it replace post-operative MRI?

Deep brain stimulation (DBS) is used to treat movement disorders, severe psychiatric disorders, and neuropathic pain, among other diseases. Advanced neuroimaging techniques allow direct or indirect localization of the target site, which is verified in many centers by the intraoperative recording of unitary neuronal activity. Intraoperative image acquisition technology (e.g., O-Arm) is increasingly used for accurate electrode positioning throughout the surgery. The aim of our study is to analyze the initial experience of our team in the utilization of O-Arm for planning DBS and monitoring its precision and accuracy throughout the procedure. The study included 13 patients with movement disorders. All underwent DBS with the intraoperative O-arm image acquisition system (iCT) and Medtronic StealthStation S7 cranial planning system, placing a total of 25 electrodes. For each patient, we calculated the difference between real and theoretic x, y, z coordinates, using the paired Student's t test to evaluate absolute and directional differences and the one-sample Student's t test to analyze differences in Euclidean distances. No statistically significant differences were found in absolute, directional, or Euclidean distances between intended and actual x, y, and z coordinates, based on iCT scan. Our experience confirms that utilization of the O-Arm system in DBS provides accurate and precise verification of electrode placements throughout the procedure. Recent studies found no significant differences between iCT and postoperative MRI, the current gold standard. Further prospective studies are warranted to test the elimination of postoperative MRI when this system is used.

[Ectopic relapse of an operated craniopharyngioma. Case report and review of the literature]. / Recidiva a distancia de craneofaringioma intervenido. Caso clínico y revisión de laliteratura.

INTRODUCTION. Craniopharyngioma is an embrionary tumor of the sellar and/suprasellar region derived from fusiform cells of Rathke´s cleft. Although locoregional relapse is the way classically proposed for relapse after treatment, it has been described, in a few cases, the possibility of ectopic relapse out of the sellar-suprasellar region, by direct seeding of cells during surgery on the surgical field, or by cell dissemination in the cerebrospinal fluid (CSF). It is proposed to report the case of a patient with relapse of a craniopharyngioma in the frontal lobe, who was previously operated ten years after, as well as to review the similar cases reported in the literature to the date. RESULTS. A systematic review of the literature has allowed to find 21 cases previously reported. Direct cellular seeding was the most frequent implantation mechanism. In all cases, the preferred treatment was radical surgical removal when this was possible. The time of latency between first surgery and relapse differed from 1 to 21 years. CONCLUSIONS. It is interesting, in the differential diagnosis, to bear in mind the possibility of ectopic relapse of craniopharyngioma in patients who have been operated because of this type of tumor and who present a new mass in nervous central system (CNS). In view of the long time of latency that can pass between the resection of a craniopharyngioma and his relapse, there becomes necessary a long follow-up of these patients by periodic imaging tests.

Recidiva a distancia de craneofaringioma intervenido. Caso clínico y revisión de la literatura / Ectopic relapse of an operated craniopharyngioma. Case report and review of the literature

Introducción. El craneofaringioma es un tumor embrionario de la región selar y/o supraselar derivado de células fusiformes de la bolsa de Rathke. Aunque la forma clásicamente propuesta para la recidiva tras el tratamiento es a nivel locorregional, se ha descrito, en raras ocasiones, la posibilidad de recidiva ectópica fuera de esta localización, bien por siembra directa de células durante la cirugía en el campo quirúrgico, bien por diseminación celular a través de líquido cefalorraquídeo (LCR). Se presenta el caso de una paciente con metástasis en el lóbulo frontal de un craneofaringioma previamente intervenido diez años antes y se revisan los casos similares publicados en la literatura hasta la fecha.Resultados. Una revisión sistemática de la literatura ha permitido encontrar 21 casos publicados previamente. La siembra celular directa fue el mecanismo de implantación más frecuente. En todos, el tratamiento de elección fue la resección quirúrgica completa, cuando esta fue posible. El tiempo de latencia entre la primera cirugía y la recidiva ectópica varió entre 1 y 21 años.Conclusiones. Es interesante tener presente en el diagnóstico diferencial la posibilidad de recidiva ectópica de craneofaringioma en pacientes que hayan sido intervenidos de este tipo de tumor y que presenten una nueva masa en sistema nervioso central (SNC). Dado el largo tiempo de latencia que puede transcurrir entre la resección de un craneofaringioma y su recidiva, se hace necesario un seguimiento largo de estos pacientes mediante pruebas periódicas de imagen (AU)

Introduction. Craniopharyngioma is an embrionary tumor of the sellar and/suprasellar region derived from fusiform cells of Rathke´s cleft. Although locoregional relapse is the way classically proposed for relapse after treatment, it has been described, in a few cases, the possibility of ectopic relapse out of the sellar-suprasellar region, by direct seeding of cells during surgery on the surgical field, or by cell dissemination in the cerebrospinal fluid (CSF). It is proposed to report the case of a patient with relapse of a craniopharyngioma in the frontal lobe, who was previously operated ten years after, as well as to review the similar cases reported in the literature to the date.Results. A systematic review of the literature has allowed to find 21 cases previously reported. Direct cellular seeding was the most frequent implantation mechanism. In all cases, the preferred treatment was radical surgical removal when this was possible. The time of latency between first surgery and relapse differed from 1 to 21 years.Conclusions. It is interesting, in the differential diagnosis, to bear in mind the possibility of ectopic relapse of craniopharyngioma in patients who have been operated because of this type of tumor and who present a new mass in nervous central system (CNS). In view of the long time of latency that can pass between the resection of a craniopharyngioma and his relapse, there becomes necessary a long follow-up of these patients by periodic imaging tests (AU)