Correlation of the epidural space measured intraoperatively and estimated by MRI or US: an observational study / Correlação entre a profundidade do espaço peridural medida no intraoperatório e a estimada por RM ou US: estudo observacional

Abstract Background and objectives: To assess the agreement between the epidural depth measured from the surgical site with the epidural depths estimated with magnetic resonance imaging (MRI) and ultrasound scanning. Methods: Fifty patients of either sex, scheduled for L4‒5 lumbar disc surgery under general anesthesia were enrolled in this prospective observational study, and the results of 49 patients were analyzed. The actual epidural depth was measured from the surgical site with a sterile surgical scale. The MRI-derived epidural depth was measured from the MRI scan. The ultrasound estimated epidural depth was measured from the ultrasound image obtained just before surgery. Results: The mean epidural depth measured from the surgical site was 53.80 ± 7.67 mm, the mean MRI-derived epidural depth was 54.06 ± 7.36 mm, and the ultrasound-estimated epidural depth was 53.77 ± 7.94 mm. The correlation between the epidural depth measured from the surgical site and MRI-derived epidural depth was 0.989 (r2 = 0.979, p < 0.001), and the corresponding correlation with the ultrasound-estimated epidural depth was 0.990 (r2 = 0.980, p < 0.001). Conclusions: Both ultrasound-estimated epidural depth and MRI-derived epidural depth have a strong correlation with the epidural depth measured from the surgical site. Preprocedural MRI-derived estimates of epidural depth are slightly deeper than the epidural depth measured from the surgical site, and the ultrasound estimated epidural depths are somewhat shallower. Although both radiologic imaging techniques provided reliable preprocedural estimates of the actual epidural depth, the loss of resistance technique cannot be discarded while inserting epidural needles.

Resumo Justificativa e objetivos: Avaliar a concordância entre a profundidade peridural medida no campo cirúrgico com a profundidade peridural estimada pela Ressonância Magnética (RM) e ultrassonografia. Métodos: Cinquenta pacientes de ambos os sexos agendados para cirurgia de disco lombar L4-5 sob anestesia geral foram incluídos neste estudo observacional prospectivo, e os resultados de 49 pacientes foram analisados. A profundidade peridural real foi medida no campo cirúrgico com uma régua cirúrgica estéril. A profundidade peridural obtida pela Ressonância Magnética (RM) foi medida a partir das imagens do exame de RM. A profundidade peridural estimada pelo ultrassom foi medida a partir da imagem do ultrassom obtida imediatamente antes da cirurgia. Resultados: A profundidade peridural média medida no campo cirúrgico foi de 53,80 ± 7,67 mm; a profundidade peridural média da RM foi de 54,06 ± 7,36 mm; e a profundidade peridural estimada por ultrassom foi de 53,77 ± 7,94 mm. A correlação entre a profundidade peridural medida no campo cirúrgico e a profundidade peridural derivada da RM foi de 0,989 (r2 = 0,979; p < 0,001); e a correlação correspondente com a profundidade peridural estimada por ultrassom foi de 0,990 (r2 = 0,980; p < 0,001). Conclusões: Tanto a profundidade peridural estimada por ultrassom quanto a profundidade peridural derivada da RM mostram forte correlação com a profundidade peridural medida no campo cirúrgico. As estimativas pré-operatórias da profundidade peridural derivadas da RM são um pouco mais profundas do que a profundidade peridural medida no campo cirúrgico, e as profundidades peridurais estimadas por ultrassom são um pouco mais rasas. Embora ambas as técnicas de imagem radiológica tenham fornecido estimativas pré-operatórias confiáveis da profundidade peridural real, a técnica de perda de resistência não pode ser descartada durante a inserção da agulha peridural.

Espacio retrodural de okada: comunicación de un caso / Retrodural space of okada: communication of a case

Se describe un caso en el que, al realizar una inyección facetaria lumbar, se observó pasaje del contraste y del corticoide hacia la faceta controlateral. se plantea que el pasaje controlateral del contraste y del corticoide se realizó a través del espacio retrodural de Okada, un espacio potencial dorsal al ligamento amarillo, que puede facilitar la comunicación entre distintos compartimientos del complejo ligamentoso posterior de la columna vertebral, en este caso entre las facetas articulares. se muestran las imágenes y se informa sobre la conducta tomada ante una imagen desconocida. se discuten otras posibles causas de pasaje controlateral del contraste, así como otras imágenes que pueden visualizarse en relación del espacio retrodural de Okada. el conocimiento de este espacio resulta de gran importancia para el anestesiólogo que realiza técnicas regionales, en particular a la hora de interpretar imágenes durante los procedimientos intervencionistas.

The following text describes a case in which during a lumbar facet injection, contrast and corticoid passage to the contralateral side was observed. the contralateral passage through the retrodural space of Okada is proposed. this is a potential dorsal space to the yellow ligament that can facilitate communication between different compartments of the posterior ligamentous complex of the spine, in this case between the articular facets. the images are shown and the behavior on an unknown image is reported. other possible causes of contralateral contrast passage are discussed, as well as other images that can be visualized in relation to the retrodural space of Okada. the knowledge of this space is of great importance for the anesthesiologist who performs regional techniques, in particular when interpreting images during interventionist procedures.

Accidental catheterization of epidural venous plexus: tomographic analysis / Cateterização acidental do plexo venoso peridural: análise tomográfica

ABSTRACT BACKGROUND AND OBJECTIVES: Inadvertent venous catheterizations occur in approximately 9% of lumbar epidural anesthetic procedures with catheter placement and, if not promptly recognized, can result in fatal consequences. The objective of this report is to describe a case of accidental catheterization of epidural venous plexus and its recording by computed tomography with contrast injection through the catheter. CASE REPORT: A female patient in her sixties, physical status II (ASA), underwent conventional cholecystectomy under balanced general anesthesia and an epidural with catheter for postoperative analgesia. During surgery, there was clinical suspicion of accidental catheterization of epidural venous plexus because of blood backflow through the catheter, confirmed by the administration of a test dose through the catheter. After the surgery, a CT scan was obtained after contrast injection through the catheter. Contrast was observed all the way from the skin to the azygos vein, passing through anterior and posterior epidural venous plexuses and intervertebral vein. CONCLUSION: It is possible to identify the actual placement of the epidural catheter, as well as to register an accidental catheterization of the epidural venous plexus, using computed tomography with contrast injection through the epidural catheter.

RESUMO JUSTIFICATIVA E OBJETIVOS: A cateterização venosa inadvertida ocorre em aproximadamente 9% das anestesias peridurais lombares com introdução de cateter e caso não seja prontamente reconhecida pode trazer consequências fatais. O objetivo deste relato é descrever um caso de cateterização acidental do plexo venoso peridural e o seu registro por tomografia computadorizada com injeção de contraste pelo cateter. RELATO DE CASO: Paciente feminina, sexagenária, estado físico II (ASA), submetida à colecistectomia convencional sob anestesia geral balanceada e peridural com cateter para analgesia pós-operatória. Durante cirurgia houve suspeição clínica de cateterização acidental do plexo venoso peridural, por refluxo de sangue pelo cateter, fato confirmado pela administração de dose-teste pelo cateter. Feita tomografia computadorizada com injeção de contraste pelo cateter, após o termino da cirurgia. Observado todo o trajeto do contraste desde a pele até a veia ázigo, passando pelo plexo venoso peridural anterior, posterior e veia intervertebral. CONCLUSÃO: É possível a identificação do real posicionamento do cateter peridural, bem como o registro da cateterização acidental do plexo venoso peridural, por meio de tomografia computadorizada com injeção de contraste pelo cateter peridural.

Clinical Outcomes of Epidural Neuroplasty for Cervical Disc Herniation

Cervical disc herniation is a common disorder characterized by neck pain radiating to the arm and fingers as determined by the affected dermatome. This condition has a favorable prognosis, but pain can have a serious detrimental impact on daily activities. Epidural neuroplasty has been applied as a treatment option for cervical disc herniation; however, no study has addressed the clinical outcomes. This retrospective study evaluated the clinical outcomes of epidural neuroplasty on 128 patients for the treatment of cervical disc herniation. To measure pain-related disabilities over time, the changes of pain scores in neck and arm were evaluated using a numerical rating scale (NRS) and the neck disability index (NDI). Compared with preprocedural values, the pain NRS of neck and arm demonstrated significant improvement at day 1, and 1, 3, 6, and 12 months after the procedure (P < 0.001). Likewise, the NDI was significantly reduced at 3, 6, and 12 months after the procedure (P < 0.001). There were no serious complications. Cervical epidural neuroplasty shows good clinical outcomes in the treatment of cervical disc herniation and can be considered a treatment modality for cervical disc herniation refractory to conservative treatment.

Epidurography

Since its introduction into clinical practice in 1921, millions of epidurals are performed daily around the world. Anesthesiologists were quick to grasp its use for prolonged or continuous analgesia and routinely use it alone or in combination with general anesthesia. It has been found to be associated with less complications as compared to spinal analgesia and has taken a major chunk out of spinal practice. The success of epidural depends upon successful location and deposition of drugs into the epidural space. Blind identification of epidural space by loss of resistance or negative epidural space pressure has resulted in mixed results. The figures vary among the researchers but in about 25-30% cases, drugs are deposited at wrong place [outside epidural space]. Epidurography offers the best method of confirming the needle or catheter tip location in the space, and has evolved itself a standard practice now. Although very rarely adverse reactions to the technique or the contrast media have been reported, the method is highly recommendable and the pain practitioners and anesthesiologists are encouraged to use it more judiciously

Pure Epidural Cavernous Hemangioma of the Cervical Spine that Presented with an Acute Sensory Deficit Caused by Hemorrhage

Pure epidural cavernous hemangioma of the spine without vertebral involvement is rare. Due to the slow growth of this lesion, the most common symptoms are chronic pain, myelopathy, and radiculopathy. In our case, the patient complained of an acute onset sensory deficit of the C4 dermatome. An MRI revealed an epidural mass with an acute hematoma. Here, we report a case of a pure epidural cavernous hemangioma that presented with acute neurologic symptoms caused by intralesional hemorrhage and an acute epidural hematoma, which were demonstrated on the patient's MRI.

Pure Epidural Cavernous Hemangioma of the Cervical Spine that Presented with an Acute Sensory Deficit Caused by Hemorrhage

Pure epidural cavernous hemangioma of the spine without vertebral involvement is rare. Due to the slow growth of this lesion, the most common symptoms are chronic pain, myelopathy, and radiculopathy. In our case, the patient complained of an acute onset sensory deficit of the C4 dermatome. An MRI revealed an epidural mass with an acute hematoma. Here, we report a case of a pure epidural cavernous hemangioma that presented with acute neurologic symptoms caused by intralesional hemorrhage and an acute epidural hematoma, which were demonstrated on the patient's MRI.