An anatomical training model for cerebrospinal liquid collection and myelography in embalmed dog cadavers / Modelo anatômico para treinamento de colheita de líquido cerebroespinhal e mielografia em cadáveres de cães quimicamente preparados

In research and academic activities, guidelines are essential and imperative especially on the use of animals. Alternative methods that do not bring academic or scientific harm should also be sought. This study aimed to develop a training model for the collection of cerebrospinal fluid (CSF) and myelography in the cervical and lumbar regions in cadavers of embalmed dogs, using an alcoholic solution and curing salts for fixation and conservation. The dogs were divided into 4 grups of 8 animal each and stored between 2ºC and 6ºC, for 30, 60, 90, or 120 days. Durotomy was performed to implant two urethral catheters (one in the cranial direction and another in the caudal direction to the spinal cord access site), in the subduraracnoid space. This space was fixed via manual infusion of saline solution with a 20-mL syringe to simulate the presence of the CSF and the positive pressure, while the puncture was made. Four cadavers of each group were randomly selected for the CSF puncture from the atlantooccipital joint and in the lumbar region between L5 and L6, respectively, and four were used for CSF puncture training, in which radiographic contrast (myelography) was injected in the same locations. This model was cost-effective, did not utilize toxic products, and can preserve cadavers for up to 120 days. In this novel anatomical model, a maximum of 15 students can be trained on CSF puncture, allowing cervical and lumbar myelography and at least 30 perforations per cadaver.

É essencial e imperioso ter critério quanto ao uso de animais em pesquisa e atividades de ensino e, consequentemente, buscar métodos alternativos que não causem prejuízo acadêmico ou científico. Para que não ocorra deterioração dos tecidos, a fixação e conservação de peças anatômicas e cadáveres devem ser realizadas. Objetivou-se, com este estudo, desenvolver um modelo anatômico para treinamento de colheita de líquido cerebroespinhal (LCE) e mielografia, nas regiões cervical e lombar. Os cães foram divididos em quatro grupos contendo oito animais cada e armazenados entre 2ºC e 6ºC, por 30, 60, 90 ou 120 dias. Foi realizada durotomia para implantação de duas sondas uretrais, no espaço subaracnóide. A infusão manual de solução fisiológica com seringa de 20 mL foi utilizada para simular a presença do LCE e a pressão positiva, enquanto era feita a punção. Quatro cadáveres de cada grupo foram selecionados para a punção de LCE na articulação atlantooccipital e na região lombar entre L5 e L6, e quatro foram utilizados para o treinamento da punção de LCE e injeção de contraste radiográfico (mielografia). A técnica anatômica empregada possibilitou o desenvolvimento de um modelo visando ao ensino e pesquisa da radiologia em cadáveres de cães quimicamente preparados, a custo baixo e sem utilização de produtos tóxicos, mantidos sob refrigeração por 120 dias. Com isso, um máximo de 15 alunos podem ser treinados em punção do LCR, permitindo mielografia cervical e lombar com 30 perfurações por cadáver.

Cierre dural primario utilizando un nudo extracorpóreo / Primary dural closure using an extracorporeal knot

Objetivo: Las cirugías espinales mínimamente invasivas (MISS) son actualmente utilizadas para una gran variedad de patologías espinales intradurales. Aunque las técnicas MISS han demostrado estar asociadas a grandes beneficios, el cierre dural primario puede constituir un desafío debido al estrecho corredor que ofrecen los sistemas retractores tubulares. El objetivo es describir una técnica de cierre dural primario en cirugías MISS. Métodos: Describimos la utilización de nudos extracorpóreos en el cierre primario de duramadre en cirugías espinales MISS con la utilización de instrumental estándar y presentamos un video demostrativo. Resultados: Se logró un cierre dural hermético con puntos separados, facilitados por la utilización de nudos extracorpóreos y sin la utilización de instrumental especializado. Conclusión: La utilización de nudos extracorpóreos facilita el cierre dural primario en cirugías MISS.

Objective: Minimally-invasive spinal surgery (MISS) is currently used for a wide variety of intradural spinal pathologies. Although MISS techniques have proven to be of great benefit, primary dural closure might be a challenge, due to the narrow corridor of tubular retractor systems. Methods: We describe employing an extracorporeal knot for primary dural closure during MISS, using standard instrumentation. We also illustrate this technique with a demonstration video. Results: Watertight dural closure with separated extracorporeal knots was performed, all without specialized instruments. Conclusion: The use of extracorporeal knots facilitates primary dural closure after MISS.

Hydrocephalus as a Complication of Durotomy during Cervical Laminoplasty: A Case Report / 대한척추외과학회지

STUDY DESIGN: Case report. OBJECTIVES: We report a case of hydrocephalus as a complication of durotomy during cervical laminoplasty. SUMMARY OF LITERATURE REVIEW: Hydrocephalus is a very rare complication of cervical laminoplasty. MATERIALS AND METHODS: A 72-year-old man had an incidental durotomy during cervical laminoplasty. The dural leak was repaired by secondary surgery. However, the patient continued to complain of headaches and developed confusion and drowsiness. A computed tomographic scan of the brain showed hydrocephalus. After insertion of a lumbar drain, the patient experienced a temporary improvement in the neurologic symptoms. After 6 months, the neurologic symptoms recurred and a ventriculoperitoneal (VP) shunt was placed. RESULTS: After placement of the VP shunt, the neurologic symptoms improved significantly. CONCLUSIONS: If a patient shows deterioration of neurologic symptoms after an incidental durotomy, surgeons should consider the possibility of hydrocephalus.

Effects of operation time of durotomy on acute spinal cord contusion / 西安交通大学学报(医学版)

Objective To study the effects of operation time of durotomy on acute spinal cord contusion. Methods Spinal cord contusion models were established in SD rats at T 9 by NYU-Ⅱ impactor.Durotomy was performed immediately(group C),1 h(group D),6 h(group E)and 12 h(group F)after spinal cord contusion, respectively.Rats in group B did not receive durotomy.Open-field locomotor function was evaluated using the Basso-Beattie-Bresnahan(BBB)locomotor rating scale at days 1,3,7,14,21 and 28 after injury in order to compare damage degree of the spinal cord.The percentage of cavity volume(CV%)and lesion length were calculated by"Imagej"software using serial sections stained by hematoxylin/eosin(HE).Results The BBB score in groups C and D was significantly better than that in group B(P ＜ 0.01);CV% and lesion length were significantly lower than those in group B(P＜0.01).The BBB score was higher in group E than in group B(P＜0.05),but lower than in groups C and D.Similarly,CV% was lower than that in group B(P＜0.05),but higher than that in groups C and D(P＜0.05).No difference was found between groups F and B in the BBB score,CV%or lesion length(P＞0.05).Conclusion Decompressive durotomy improved motor function recovery and reduced the damage of the spinal cord in the setting of a thoracic spinal cord contusion injury in SD rats within 6 h after injury.Durotomy 12 h after injury does not affect function outcomes or spinal cord injury after injury.

Incarceration of Spinal Nerve Root through Incidental Durotomy as a Cause of Sciatica

Incidental durotomies are a frequent complication during spinal surgery. Cerebrospinal fluid (CSF) leakage from a dural tear may be visually apparent intraoperatively, but occasionally, a tear may not be recognized during the procedure. We report our experience in 2 cases of postoperative incarceration of nerve root as a cause of sciatica, without CSF leakage intraoperatively. When durotomy attributable to surgical manipulation does occur, intraoperative identification is mandated. If a patient develops unexplainable postoperative pain and neurological deficits after lumbar discectomy, incarceration of nerve root should be considered in the differential diagnosis.

Incidental Dural Tears During Lumbar Spine Surgery: A Retrospective Case Study of 84 Degenerative Lumbar Spine Patients

STUDY DESIGN: A retrospective case study. PURPOSE: To retrospectively review all incidental dural tears (DTs) that occurred at a single institution, classify them anatomically and evaluate the clinical significance of each subgroup. OVERVIEW OF LITERATURE: Dural tears are considered the most commonly encountered complication during lumbar spine surgery. In contrast to the high frequency of DTs, reports on the characteristic location and mechanism are sparse. METHODS: We retrospectively retrieved all cases of degenerative lumbar spine surgery performed over a 9-year period and classified all identified DTs according to two independent planes. The coronal plane was divided into lower, middle and upper surgical fields, and the sagittal plane into posterior, lateral and ventral occurring tears. Demographic and clinical variables were retrieved and analyzed to search for significant associations. RESULTS: From 2003 to 2011, 1,235 cases of degenerative lumbar spine conditions were treated surgically at our institution. In 84 operations (6.8%), an incidental DT was either identified intraoperatively or suspected retrospectively. The most commonly involved location was the lower surgical field (n=39, 46.4%; p=0.002), followed equally by the middle and upper fields (n=16, 19%). In the sagittal plane, the most commonly involved locations were those in close proximity to the nerve root (n=35, 41.6%), followed by the dorsal aspect of the dural sac (n=24, 28.6%). None of the variables recorded was found to be associated with a particular location. CONCLUSIONS: In our series, incidental DTs were found to occur most commonly in the lower surgical field. We hypothesize that local anatomic feature, such as the lordotic and broadening lumbar dura, may play a role in the observed DT tendency to occur in the lower surgical field. In light of the high frequency and potentially substantial resulting morbidity of incidental DTs, a better characterization of its location and mechanism may optimize both prevention and management.

Therapeutic Results of CSF Leakage due to Unintended Incidental Durotomy in Spine Surgery

OBJECTIVE: This study is designed to analyse the result of cerebrospinal fluid(CSF) leakage due to unintended incidental durotomy in spine surgery and to determine the timing of repair operation for CSF leakage. METHODS: Iatrogenic dura tearing occurred in 114 cases among the 1626 spine operation patients. This study included 29 consecutive patients with postoperative CSF leakage at the operative wound who did not underwent intraoperative dural closure. RESULTS: Of the 29 patients in this study, 24% had clinical symptom after CSF leakage. Four patients reported headache, three reported aggravation of lumbago. Reoperation for dura or wound repair were performed in 12 cases. Incidence of reoperation was higher in patients who underwent total laminectomy including resection of spinous process than in those who underwent partial hemilaminectomy. The CSF obtained at the reoperation was cultured. Staphylococcus aureus were cultured in 5 patients and not in 7 patients. The mean period between reoperation and the first CSF wound leakage was longer in culture positive group(14.8days) than in culture negative group(6.6days). The period between reoperation and the first CSF leakage in all of the culture positive patients was longer than 10 days. CONCLUSION: In case that CSF wound leakage in total laminectomy patients persist longer than 10days in spite of conservative management, we recommend to perform dura/wound repair without delay.

Incidental Dural Tear during Posterior Surgery of Degenerative Lumbar Disease / 대한척추외과학회지

STUDY DESIGN: A retrospective study. OBJECTIVE: To analyze the clinical features and prognosis of intraoperative incidental durotomy during posterior surgery for degenerative lumbar disease. In addition, we tried to evaluate clinical outcome and safety of skillful neglect of pin point dural tear. SUMMARY OF LITERATURE REVIEW : Incidental durotomy is one of the most common complications during the operation of degenerative lumbar disease. It may cause signs and symptoms of cerebrospinal fluid leakage and complications such as meningitis, wound infection, pseudomeningocele and fistula. From the literature review, primary repair is mandatory even in the case of pin point dural tear. MATERIALS AND METHODS: Seven hundred fifty-five patients with degenerative lumbar disease, who were operated posteriorly from Jan. 1990 to Feb. 2002, were reviewed retrospectively. Primary operations were 378 cases of laminectomy without instrumentation and 377 cases of decompression and instrumented fusion. Of these patients, 44 (6 percent) sustained an incidental dural tear. We analyzed the mechanisms of dural tear, intraoperative treatment, postoperative management and clinical outcome. RESULTS: Eight cases (2.1%) of dural tears occurred during discectomy, 36 (9.5%) during instrumentation and fusion, and 12 (20%) during revision surgery. Dural tears were treated intraoperatively by primary repair in 20 cases, by fascial graft in 2 and without repair (skillful neglect) in 22. There were no cases of persistent cerebrospinal fluid leakage or fistula formation, and the symptoms of cerebrospinal fluid leakage were transient. Of 36 patients followed for more than one year, 82% had good or excellent result. CONCLUSION: Incidental durotomy occurred in 5.8 percent of lower back surgery patients, and more frequently in revision surgery. Very small dural tears did not have significant influence on the clinical outcome, whether they were repaired or not. Skillful neglect of pin point dural tear may be a reasonable treatment option.