RESUMO
BACKGROUND: Surgery of thickened-fibrolipoma filum terminale (FT) is performed routinely and without conflict but is not a risk-free surgical procedure. Intraoperative neurophysiological monitoring with mapping techniques can help to certify the FT before sectioning. However, a tailored surgical approach to cauda equina and a low threshold of surrounding nerve roots can confuse the final surgical decision. The aim is to demonstrate the usefulness of this double methodology for FT certification. METHODS: A prospective study collected and reviewed retrospectively, from 2015 to 2018, 40 patients undergoing an FT surgery section were included in the study. After opening the dura mater and under the microscope, the cauda equina mapping is performed and the recording of muscles of the lower limbs and the external anal sphincter. In addition, a high-intensity stimulation of constant current of an isolated FT for a short period of time and in a dry surgical field, obtaining a bilateral-polyradicular-symmetrical response of cauda equina nerve roots. RESULTS: Traditional motor mapping identified FT in 65% (26/40) of patients. Although, 35% (14/40) of the patients still have low-intensity stimuli response (<1 mA) of a muscle, especially anal sphincter. When this happens, the optimization of the dissection around FT is performed. After that, 25% (10/40) of the patients still having a muscle response in spite of seem isolated FT. Increasing the stimulation intensity up to 20 mA evoked a cauda equina response in all cases. No postoperative neurological impairment was observed in this series. CONCLUSION: This proposed methodology accurately confirms the FT so that it can be safely found and cut. The Double Neurophysiological Certification improves the gap of the traditional mapping techniques of cauda equina and can be used in a variety of more complex surgeries in this area.
RESUMO
BACKGROUND: The standard of care is to utilize intraoperative neurophysiological monitoring (IOM) of triggered electromyography (tEMG) during posterior lumbosacral instrumented-fusion surgery. IOM should theoretically signal misplacement of S1 screws into the neural L5-S1 foramen or spinal canal, utilizing screw stimulation, and recording of the lower limb muscles and the anal sphincter. Here, we evaluated when and whether anterolateral S1 screw malposition could be detected by IOM/tEMG during open posterior lumbosacral instrumented fusion surgery. METHODS: tEMG, somatosensory-evoked potential (SSEP), and transcranial electrical motor-evoked potential (TcMEP) data were retrospectively reviewed from 2015 to 2017 during open posterior lumbosacral instrumented fusions. We utilized screw stimulation alert thresholds of <14 mA (tEMG) and recorded from the lower extremity muscles and anal sphincter. Furthermore, all patients underwent routine postoperative computed tomography (CT) scans to confirm the screw location. RESULTS: There were 106 S1 screws placed in 54 patients: 52 bilateral and 2 unilateral. In 6 patients (11.1%), 7 screws (6.6%) registered at low tEMG thresholds. In 1 patient, the postoperative CT scan documented external malposition of the screw despite no intraoperative IOM/tEMG alert. When S1 misplaced screws were stimulated, the most sensitive muscle was the tibialis anterior; the sensitivity of the IOM/tEMG was 87.5%, the specificity was 97.9%, the positive predictive value was 77.8%, and the negative predictive value was 98.9%. TcMEP and SSEP did not change during any of the operations. Notably, no patient developed a new neurological deficit. CONCLUSION: Anterolateral S1 screw malposition can be detected accurately utilizing IOM/tEMG stimulation of screws. When alerts occur, they can largely be corrected by partially backing out the screw (e.g., a few turns) and/ or changing the screw trajectory.
RESUMO
Objetivo. Determinar las características clínicas y epidemiológicas de los Aneurismas cerebrales, a partir de los datos encontrados. Materiales y método. Se realizó un estudio retrospectivo descriptivo, en el cual se revisaron protocolos de seguimiento de pacientes portadores de Aneurismas Cerebrales en el Hospital Clínico Regional de Concepción, desde agosto del año 2000 hasta febrero del año 2002, tabulando y analizando los resultados. Resultados. De 38 protocolos revisados, encontramos 2 pacientes fallecidos. Predominó el sexo femenino con un 73,68 por ciento, la edad promedio fue 48,79 años (DE + 13.67) y el antecedente mórbido más encontrado fue la hipertensión arterial crónica en un 39,47 por ciento de los pacientes. Respecto al ingreso, el 69,69 por ciento tenía Score de Glasgow mayor o igual a 13 y el 54,83 por ciento tenía grado III de Hunt y Hess. Los signos clínicos más encontrados fueron los de irritación meníngea (60,52 por ciento) seguidos por el tercer par. El 100 por ciento de los aneurismas se ubicó en la circulación anterior. La media de días previos a la cirugía y de días de hospitalización de los pacientes fue de 14,95 (DE + 10,04) y 29,74 días (DE + 10,21) respectivamente. Finalmente el 50 por ciento de los pacientes presentó Karnofsky de egreso igual a 100. Conclusión. Los aneurismas cerebrales son una patología de gran importancia por las repercusiones que tiene tanto para el paciente como para la sociedad.