Early adjunctive methylene blue in patients with septic shock: a randomized controlled trial.

PURPOSE: Methylene blue (MB) has been tested as a rescue therapy for patients with refractory septic shock. However, there is a lack of evidence on MB as an adjuvant therapy, its' optimal timing, dosing and safety profile. We aimed to assess whether early adjunctive MB can reduce time to vasopressor discontinuation in patients with septic shock. METHODS: In this single-center randomized controlled trial, we assigned patients with septic shock according to Sepsis-3 criteria to MB or placebo. Primary outcome was time to vasopressor discontinuation at 28 days. Secondary outcomes included vasopressor-free days at 28 days, days on mechanical ventilator, length of stay in ICU and hospital, and mortality at 28 days. RESULTS: Among 91 randomized patients, forty-five were assigned to MB and 46 to placebo. The MB group had a shorter time to vasopressor discontinuation (69 h [IQR 59-83] vs 94 h [IQR 74-141]; p < 0.001), one more day of vasopressor-free days at day 28 (p = 0.008), a shorter ICU length of stay by 1.5 days (p = 0.039) and shorter hospital length of stay by 2.7 days (p = 0.027) compared to patients in the control group. Days on mechanical ventilator and mortality were similar. There were no serious adverse effects related to MB administration. CONCLUSION: In patients with septic shock, MB initiated within 24 h reduced time to vasopressor discontinuation and increased vasopressor-free days at 28 days. It also reduced length of stay in ICU and hospital without adverse effects. Our study supports further research regarding MB in larger randomized clinical trials. Trial registration ClinicalTrials.gov registration number NCT04446871 , June 25, 2020, retrospectively registered.

Assessment of Paraspinal Muscle Atrophy Percentage after Minimally Invasive Transforaminal Lumbar Interbody Fusion and Unilateral Instrumentation Using a Novel Contralateral Intact Muscle-Controlled Model.

STUDY DESIGN: Retrospective comparative clinical study. PURPOSE: This study aimed to assess paraspinal muscle atrophy in patients who underwent minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) and unilateral pedicle screw fixation using a novel contralateral intact muscle-controlled model. OVERVIEW OF LITERATURE: The increased incidence of paravertebral lumbar muscle injuries after open techniques has raised the importance of implementing minimally invasive spine surgical techniques using tubular retractors and minimally invasive screw placement. The functional cross-sectional area (FCSA) represents the lean muscle mass; furthermore, FCSA is a useful marker of the contractile ability of a muscle following a spine surgery. However, the benefits of unilateral fixation and MI-TLIF on paraspinal muscles have not been defined. METHODS: We performed a retrospective imagenological review on eleven patients who underwent unilateral MI-TLIF and unilateral transpedicular screw lumbar placement. FCSAs of the multifidus and erector spinae were measured 1 year after surgery at adjacent levels and were compared to the contralateral intact muscles. Measurement differences between the surgical and nonsurgical sites were compared. The interobserver reliability was calculated using an intraclass correlation coefficient. RESULTS: The mean FCSA at the surgical site was 20.97±5.07 cm2 at the superior level and 8.89±2.87 cm2 at the inferior level. The mean FCSA at the contralateral nonsurgical site was 20.15±5.95 cm2 at the superior level and 9.20±2.66 cm2 at the inferior level was. The superior and inferior FCSA measurements showed no significant difference between the surgical and nonsurgical sites (p=0.5, p=0.922, respectively). CONCLUSIONS: Using a mini-open tubular approach through the sulcus between the longissimus and iliocostalis, MI-TLIF and unilateral pedicle screw instrumentation produced minimal paraspinal muscle damage at the superior and inferior adjacent levels.

Learning curve in single-level minimally invasive tlif: experience of a neurosurgeon / Curva de aprendizagem em tlif minimamente invasiva em um nível: experiência de um neurocirurgião / Curva de aprendizaje en tlif por mínima invasión de un nivel: experiencia de un neurocirujano

ABSTRACT Objective: To describe the learning curve that shows the progress of a single neurosurgeon when performing single-level MI-TLIF. Methods: We included 99 consecutive patients who underwent single-level MI-TLIF by the same neurosurgeon (JASS). Patient's demographic characteristics were analyzed. In addition, surgical time, intraoperative blood loss and hospital stay were evaluated. The learning curves were calculated with a piecewise regression model. Results: The mean age was 54.6 years. The learning curves showed an inverse relationship between the surgical experience and the variable analyzed, reaching an inflection point for surgical time in case 43 and for blood loss in case 48. The mean surgical time was 203.3 minutes (interquartile range [IQR] 150-240 minutes), intraoperative bleeding was 97.4ml (IQR 40-100ml) and hospital stay of four days (IQR 3-5 days). Conclusions: MI-TLIF is a very frequent surgical procedure due to its effectiveness and safety, which has shown similar results to open procedure. According to this study, the required learning curve is slightly higher than for open procedures, and is reached after about 45 cases.

RESUMO Objetivo: Descrever a curva de aprendizagem que mostra o progresso de um único neurocirurgião na realização de MI-TLIF em um só nível. Métodos: Foram incluídos 99 pacientes consecutivos submetidos a MI-TLIF de um só nível pelo mesmo neurocirurgião (JASS). Foram analisadas as características demográficas dos pacientes. Além disso, avaliou-se o tempo operatório, a perda de sangue intraoperatória e o tempo de internação hospitalar. As curvas de aprendizagem foram realizadas com um modelo de regressão segmentada. Resultados: A média de idade foi 54,6 anos. As curvas de aprendizagem mostraram uma relação inversa entre a experiência cirúrgica e a variável analisada, atingindo um ponto de inflexão para o tempo de cirurgia no caso 43 e da perda sanguínea no caso 48. O tempo médio de cirurgia foi de 203,3 minutos (amplitude interquartil [IQR] 150 - 240 minutos), de sangramento intraoperatório foi 97,4 ml (IQR 40-100 ml) e de internação hospitalar foi de quatro dias (IQR 3-5 dias). Conclusões: O MI-TLIF é um procedimento realizado com muita frequência devido à sua eficácia e segurança, que tem mostrado resultados comparáveis com o procedimento aberto. De acordo com este estudo, a curva de aprendizagem necessária é ligeiramente maior do que para os procedimentos abertos, sendo que é atingida depois de cerca de 45 casos.

RESUMEN Objetivo: Describir la curva de aprendizaje que muestre el progreso de un sólo neurocirujano para la realización de MI-TLIF de un sólo nivel. Métodos: Se incluyeron 99 pacientes consecutivos sometidos a MI-TLIF en un solo nivel por un mismo neurocirujano (JASS). Se analizaron las características demográficas de los pacientes. Además se evaluó el tiempo quirúrgico, sangrado transoperatorio y tiempo de estancia hospitalaria. Las curvas de aprendizaje se realizaron con un modelo de regresión dividida en segmentos. Resultados: Se obtuvo un promedio de edad de 54,6 años. Las curvas de aprendizaje mostraron una relación inversa entre la experiencia quirúrgica y la variable analizada, alcanzando un punto de inflexión para tiempo quirúrgico en el caso 43 y para el sangrado en el caso 48. El promedio de tiempo quirúrgico fue de 203,3 minutos (amplitud intercuartil [IQR] 150 - 240 minutos), del sangrado transoperatorio fue 97,4 ml (IQR 40 - 100 ml) y de la estancia hospitalaria fue de cutro días (IQR 3 - 5 días). Conclusiones: El MI-TLIF es un procedimiento realizado con gran frecuencia debido a su efectividad y seguridad y que ha demostrado resultados equiparables con el procedimiento abierto. De acuerdo a este estudio la curva de aprendizaje requerida es discretamente mayor que para procedimientos abiertos, alcanzándola aproximadamente tras 45 casos.

A prospective clinical study comparing MI-TLIF with unilateral versus bilateral transpedicular fixation in low grade lumbar spondylolisthesis.

BACKGROUND: Minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) has become one of the standard techniques for approaching ipsilateral decompression, anterior column fusion, and posterior stabilization. This procedure is usually accompanied by the placement of bilateral transpedicular screws in the corresponding segment. The purpose of this study was to evaluate the clinical efficacy of unilateral screw fixation compared with bilateral fixation in patients diagnosed with low-grade symptomatic lumbar spondylolisthesis who underwent an MI-TLIF technique. METHODS: A prospective and comparative study was performed in 67 patients with grade 1 symptomatic lumbar spondylolisthesis. The sample was allocated on both unilateral fixation group (n=33) and bilateral fixation group (n=34). Clinical outcomes were evaluated using Oswestry Disability Index (ODI), visual analogue scale (VAS) for leg and back pain, and Short Form 36 Health Survey (SF-36), preoperatively, and at 1, 3, 6, and 12 months postoperatively. Changes over time and differences between the groups were analyzed. Statistical analyses included: Friedman test, Student's t-test and Mann-Whitney's U. A two-tailed P value of <0.05 was considered significant. RESULTS: During 1-year of evaluation there were no significant clinical differences between both groups. CONCLUSIONS: Patients with grade 1 symptomatic lumbar spondylolisthesis treated with MI-TLIF with unilateral screw fixation had similar clinical results than those treated with bilateral fixation at 12 months postoperatively.

Microscopy-assisted interspinous tubular approach for lumbar spinal stenosis.

Various minimally invasive techniques have been reported as an alternative to conventional lumbar decompression. The major advantage of these minimally invasive procedures lies in their reduction of unnecessary exposure and tissue trauma. Our objective was to describe a minimally invasive procedure for lumbar spinal stenosis decompression by enlarging the lumbar interspinous space, approaching it with a tubular retractor, and assisting with microscopy. Thoracolumbar fascia and paravertebral muscles are preserved throughout the whole procedure. Iatrogenic instability of the spine can be avoided if during the procedure both joints are just undercut in order to decompress the subarticular space. The approach described in this manuscript could be used as an alternate minimally invasive surgical procedure for the treatment of central and lateral lumbar spinal stenosis.

[Spinal extradural arachnoid cyst: A case report and review of literature]. / Quiste aracnoideo extradural espinal: reporte de un caso y revisión de la literatura.

BACKGROUND: Arachnoid cysts of spine are a very rare occurrence. The aetiology still remains unclear, but the most accepted explanation is the existence of areas of weakness in the spinal dura. Symptoms depend on the location in the spine. Magnetic resonance imaging is used for its diagnosis. Management depends of clinical presentation, and the surgery is reserved for patients with neurological impairment. CLINICAL CASE: A case is described of 67 year-old male with myelopathy and radiculopathy symptoms, both diagnosed simultaneously. The magnetic resonance imaging was used to diagnose a thoracolumbar extradural arachnoid cyst from T12-L2 and lumbar spinal canal stenosis. The patient was treated with a puncture procedure to empty the cyst and decompress the neural elements. There was a clinical improvement of myelopathy syndrome after puncture procedure. One month later, the patient underwent a minimally invasive surgical approach to decompress the neural elements in lumbar spine, achieving improvement of the radiculopathy syndrome and neurogenic claudication in both legs. CONCLUSION: There is currently no standard minimally invasive approach to surgically treat these cysts, but if the patient has mild symptoms, clinical observation is recommended.

Diagnóstico simultáneo de pseudomeningocele, síndrome de médula anclada y fístula de líquido cefalorraquídeo: a propósito de un caso / Simultaneous diagnosis of pseudomeningocele, tethered cord syndrome and cerebrospinal fluid fistula: Report of a case

El caso clínico alude a una paciente con disrafismo sacro extenso, antecedentes de reparación de mielomeningocele en su infancia y signos y síntomas de síndrome de médula anclada. Se diagnosticó además pseudomeningocele y fístula de líquido cefalorraquídeo cutánea. El abordaje quirúrgico fue realizado con resultados alentadores en la evolución de la paciente. Se realizó además una revisión de la literatura, para fundamentar el tratamiento quirúrgico utilizado en este caso

The clinical case is presented on a patient with an extensive sacral dysraphism, a history of myelomeningocele surgical repair in her childhood, as well as tethered cord syndrome. The patient was also diagnosed with pseudomeningocele and a cerebrospinal fluid cutaneous fístula. A surgical approach was used, with encouraging results being obtained in the clinical outcome of the patient. A review of the literature was performed to support the surgical decision in this case

[Simultaneous diagnosis of pseudomeningocele, tethered cord syndrome and cerebrospinal fluid fistula: Report of a case]. / Diagnóstico simultáneo de pseudomeningocele, síndrome de médula anclada y fístula de líquido cefalorraquídeo: a propósito de un caso.

The clinical case is presented on a patient with an extensive sacral dysraphism, a history of myelomeningocele surgical repair in her childhood, as well as tethered cord syndrome. The patient was also diagnosed with pseudomeningocele and a cerebrospinal fluid cutaneous fístula. A surgical approach was used, with encouraging results being obtained in the clinical outcome of the patient. A review of the literature was performed to support the surgical decision in this case.

Microsurgical landmarks in minimally invasive transforaminal lumbar interbody fusion / Referências microcirúrgicas em fusão intersomática lombar transforaminal minimamente invasiva / Referencias microquirúrgicas en la fusión intersomática lumbar transforaminal de mínima invasión

Microsurgical landmarks of the facet joint complex were defined to provide guidance and security within the tubular retractor during transforaminal surgery. A retrospective observational study was performed in segments L4-L5 by the left side approach. Microsurgical relevant photos, anatomical models and drawing were used to expose the suggested landmarks. The MI-TLIF technique has advantages compared with conventional open TLIF technique, however minimally invasive technique implies lack of security for the surgeon due to the lack of defined microanatomical landmarks compared to open spine surgery, and disorientation within the tubular retractor, the reason why to have precise microsurgical references and its recognition within the surgical field provide speed and safety when performing minimally invasive technique.

Foram definidas referências anatômicas microcirúrgicas do complexo facetário para obter orientação e segurança no interior do retrator tubular durante a cirurgia transforaminal. Realizou-se um estudo observacional retrospectivo dos procedimentos MI-TLIF nos segmentos L4-L5 com acesso lateral esquerdo. Foram empregados fotos microcirúrgicas relevantes, modelo anatômico e esquemas para expor as referências sugeridas. A técnica de MI-TLIF tem vantagens quando comparada com a técnica TLIF a céu aberto convencional, no entanto, a técnica minimamente invasiva implica falta de segurança para o cirurgião, devido à ausência de referências microanatômicas definidas em comparação com a cirurgia a céu aberto, além de falta de orientação no interior do retrator tubular. Por isso, ter referências microcirúrgicas precisas e seu reconhecimento dentro do campo cirúrgico proporciona rapidez e segurança ao realizar a técnica minimamente invasiva.

Se definieron las referencias anatómicas microquirúrgicas del complejo facetario para aportar orientación y seguridad dentro del portal tubular durante la cirugía transforaminal. Se realizó un estudio observacional retrospectivo de procedimientos MI-TLIF en segmentos L4-L5 abordados del lado izquierdo. Se utilizaron fotos microquirúrgicas relevantes, modelo anatómico y esquemas para exponer las referencias anatómicas sugeridas. La técnica de MI-TLIF tiene ventajas comparada con la técnica abierta convencional de TLIF, sin embargo la técnica mínimamente invasiva confiere falta de seguridad para el cirujano debido a la carencia de referencias microanatómicas definidas comparado con la cirugía abierta y desorientación dentro del acceso tubular por lo que tener referencias microquirúrgicas precisas y su reconocimiento dentro del campo quirúrgico aportan rapidez y seguridad al realizar la técnica mínimamente invasiva.

Fluoroscopy-guided pedicle screw accuracy with a mini-open approach: a tomographic evaluation of 470 screws in 125 patients.

BACKGROUND: Transpedicular screws are currently placed with open free hand and minimally invasive techniques assisted with either fluoroscopy or navigation. Screw placement accuracy had been investigated with several methods reaching accuracy rates from 71.9% to 98.8%. The objective of this study was to assess the accuracy and safety for 2-D fluoroscopy-guided screw placement assisted with electrophysiological monitoring and the inter-observer agreement for the breach classification. METHODS: A retrospective review was performed on 125 consecutive patients who underwent minimally invasive transforaminal lumbar interbody fusion and transpedicular screws placement between the levels of T-12 and S-1. Screw accuracy was evaluated using a postoperative computed tomography by three independent observers. Pedicle breach was documented when there was a violation in any direction of the pedicle. Inter-observer agreement was assessed with the Kappa coefficient. RESULTS: A total of 470 transpedicular screws were evaluated between the levels of T-12 and S-1. In 57 patients the instrumentation was bilateral and in 68 unilateral. A substantial degree of agreement was found between the observers AB (κ=0.769) and A-C (κ=0.784) and almost perfect agreement between observers B-C (κ=0.928). There were a total of 427.33 (90.92%) screws without breach, 39.33 (8.37%) minor breach pedicles and 3.33 (0.71%) major breach pedicles. The pedicle breach rate was 9.08% Trajectory pedicle breach percentages were as follows: minor medial pedicle breach 4.68%, minor lateral pedicle breach 3.47%, minor inferior pedicle breach 0.22%, and major medial breach 0.70%. No intraoperative instrumentation-related or postoperative clinical complications were encountered and no surgical revision was needed. CONCLUSIONS: Our study demonstrated a high accuracy (90.2%) for 2-D fluoroscopy-guided pedicle screw using electromonitoring. Only 0.71% of the 470 screws had a major breach. Knowing the radiological spine pedicle anatomy and the correct interpretation of EMG are the key factors for this technique.

Altered neurotransmitter release, vesicle recycling and presynaptic structure in the pilocarpine model of temporal lobe epilepsy.

In searching for persistent seizure-induced alterations in brain function that might be causally related to epilepsy, presynaptic transmitter release has relatively been neglected. To measure directly the long-term effects of pilocarpine-induced status epilepticus on vesicular release and recycling in hippocampal mossy fibre presynaptic boutons, we used (i) two-photon imaging of FM1-43 vesicular release in rat hippocampal slices; and (ii) transgenic mice expressing the genetically encoded pH-sensitive fluorescent reporter synaptopHluorin preferentially at glutamatergic synapses. In this study we found that, 1-2 months after pilocarpine-induced status epilepticus, there were significant increases in mossy fibre bouton size, faster rates of action potential-driven vesicular release and endocytosis. We also analysed the ultrastructure of rat mossy fibre boutons using transmission electron microscopy. Pilocarpine-induced status epilepticus led to a significant increase in the number of release sites, active zone length, postsynaptic density area and number of vesicles in the readily releasable and recycling pools, all correlated with increased release probability. Our data show that presynaptic release machinery is persistently altered in structure and function by status epilepticus, which could contribute to the development of the chronic epileptic state and may represent a potential new target for antiepileptic therapies.