Histopathological Study of the Effects of Dura Adhesive Agents Used in Spinal Surgery Practice on Spinal Epidural Fibrosis in Experimental Animal Model

Objective

Histopathological examination of the effects of Tisseel, Cova, Glubran and Coseal, which are used for sealing purposes in spinal surgery practice, on epidural fibrosis is aimed.

Methods

Forty Sprague Dawley rats were randomly divided into five groups in our study as Group 1 (n=8) control group (Laminectomy); Group 2 (n=8) Cova group (Laminectomy + Cova); Group 3 (n=8) Tissel group (Laminectomy + Tisseel); Group 4 (n=8) Coseal group (Laminectomy + Coseal); and Group 5 Glubrane group (Laminectomy + Glubrane). Control group was only applied laminectomy. After laminectomy to other groups, Cova was applied to the 2nd group, Tissel to the 3rd group, Coseal to the 4th group and Glubran to the 5th group in surgical fields. After the rats were monitored in separate cages for 6 weeks after the operation, the relevant spinal level was extracted and the samples were examined histopathologically and the results were evaluated statistically.

Results

It was found that there was a statistically significant difference in Tisseel and Glubran groups in terms of fibrosis grading compared to the control group, and this had a positive effect on fibrosis. Compared to the control group, there was no statistically significant difference on fibrosis in Cova and Coseal groups.

Conclusion

As dura adhesive agents used in spinal surgery practice did not increase spinal epidural fibrosis statistically significantly, we concluded that these products can be used safely during spinal surgery if necessary.

[Clinical research progress of spinal epidural lipomatosis]

Objective

To review the clinical research progress of spinal epidural lipomatosis (SEL).

Methods

The clinical studies on SEL at home and abroad in recent years were extensively reviewed, and the pathogenesis, clinical and imaging manifestations, and treatment status of SEL were summarized and analyzed.

Results

SEL is a disease characterized by compression of the spinal cord and nerve roots due to abnormal accumulation of epidural adipose tissue in the spinal canal. Its prevalence and diagnosis rate are low and the pathogenesis is not fully understood. MRI is the most sensitive and specific diagnostic test for SEL. Surgical decompression and removal of excess adipose tissue are the only options for patients with acute SEL or those who have failed conservative management, and conservative management should be considered for other patients.

Conclusion

SEL is a rare disease and related research still needs to be improved. In the future, high-quality, multi-center and large-sample studies will be of great significance for evaluating the choice of treatment methods and effectiveness of SEL patients.

Temperature change of epidural space by radiofrequency use in biportal endoscopic lumbar surgery: safety evaluation of radiofrequency

PURPOSE

Articles evaluating radiofrequency (RF) safety are insufficient. Thus, the purpose of this study was to investigate RF safety during biportal endoscopic lumbar decompressive laminotomy by measuring epidural temperature after RF use.

METHODS

Both in vitro cadaveric study and in vivo study were performed. The epidural temperature was measured at epidural space after RF use in three cadavers. The epidural temperature was measured and analysed according to RF mode, RF power, RF usage time, and saline irrigation patency. In the in vivo study, the epidural temperature was measured after biportal endoscopic surgery. Epidural temperatures were measured around ipsilateral and contralateral traversing nerve roots after 1-s use of RF.

RESULTS

In the in vivo study, epidural space temperature was increased by 0.31 ± 0.16 °C ipsilaterally and 0.29 ± 0.09° contralaterally after RF use in coagulation mode 1. The epidural temperature of epidural space was increased by 0.21 ± 0.13 °C ipsilaterally and 0.15 ± 0.21 °C contralaterally after RF use in high mode 2. In the in vitro study, epidural temperature was significantly increased with a long duration of RF use and a poor patency of irrigation fluid.

CONCLUSION

The use of RF in biportal endoscopic spine surgery might be safe. In order to reduce indirect thermal injuries caused by RF use, it might be necessary to reduce RF use time and maintain continuous saline irrigation patency well.

The Mysterious Role of Epidural Fat Tissue in Spine Surgery: A Comprehensive Descriptive Literature Review

BACKGROUND

Though both neurosurgeons and orthopedic spinal surgeons are keenly aware of the clinical importance of epidural fat (EF), surgical practice varies amongst individual surgeons and across both fields. Thus, an in-depth understanding of the anatomical structure and composition of EF is vital, as it will play a significant role in the therapeutic management and the surgical choice of treatment.

OBJECTIVE

We aim to extensively review the anatomical and biological properties of EF and further outline the surgical importance of EF management.

STUDY METHODOLOGY

(i) MEDLINE search 1966-July 2019. Keywords: Review of the Literature. Authorship, Meta-analysis, Descriptive/Narrative overview; (ii) CINAHL search from 1982 to May 2019. Keywords: Review of the Literature spinal epidural fat; Authorship; Meta-analysis; Descriptive/Narrative overview; (iii) Hand searches of the references of retrieved literature; (iv) Personal and college libraries were searched for texts on research methods and literature reviews; and (v) 200 articles were downloaded, 50 were excluded because of similarity of topics and also because of new update on the same topics. (vi) Discussions with experts in the field of reviews of the literature.

DISCUSSION

Though excessive or reductive amounts of EF usually exacerbates neurological symptoms and lead to various pathologic conditions such as spinal epidural lipomatosis, but there is no basic science, experimental, or clinical research that proves the role of EF in the aforementioned pathologic situations.

CONCLUSION

Anatomical illustration, biological function and properties of EF knowledge may lead to changes in the stages of the surgical approach to avoid postoperative complications. However, the role of EF is exclusively bound to a scientific hypothesis as one cannot be sure if an excessive or reductive amount in EF is entirely responsible for the pathologic findings, or just only an incidental finding.

IgG4-related Pachymeningitis as a Cause of Spinal Epidural Compression: Can Intraoperative Frozen Sections Predict the Underlying Pathology?

At times, spinal lesions are part of systemic manifestations of autoimmune disease. Awareness regarding their clinicopathological spectrum, particularly the lesions which usually respond to steroids/immunotherapy, is essential to avoid unwanted surgical morbidity. We discuss a case of a young-man presenting with thoracic spinal epidural compressive lesion which was indeed a manifestation of IgG4-related hypertrophic pachymeningitis. The mass was firmly adherent to the dura and extended into left neural foramen/paravertebral space which precluded complete excision. Frozen sections suggested fibro-inflammatory stroma with large areas of fibrosis and lymphoplasmacytic infiltrate. After subtotal excision, the patient improved with medical therapy at 1-year follow-up. Although uncommon, the case highlights the need to consider spinal presentation of this rare entity, especially in the context of autoimmune disorders or even in isolation. In this regard, intraoperative frozen section can hint the underlying inflammatory/autoimmune pathology, guide further course of surgery as well as limit unwarranted operative morbidity.

Isolated primary spinal epidural hydatid cyst in a child with progressive paraparesis

BACKGROUND

Primary spinal hydatid cyst is a rare but serious condition which occurs in about 1% of patients with hydatid disease. This disease may result in severe spinal cord compression presenting with various neurological deficits.

CASE REPORT

A 3-year-old boy was referred to our center with progressive weakness of lower limbs, frequency, and urinary incontinence. His parents did not report back pain during child's illness. Lumbar magnetic resonance imaging (MRI) revealed an extradural well-defined thin-walled cystic lesion at L4 to S3 vertebral levels without enhancement. The cyst had compressed the thecal sac associated with bone scalloping of vertebral bodies and posterior elements. Osteoplastic laminectomy of L4-L5 and laminectomy of S1-S3 was done. Intraoperative and histopathological findings indicated an epidural hydatid cyst.

CONCLUSION

Although spinal hydatid cysts are rare but might be considered in the differential diagnosis of any patient with signs and symptoms of spinal cord compression. The pathophysiology, clinical manifestations, epidemiology, diagnosis, and surgical treatment of extradural hydatid cyst are discussed.

[Minimally invasive treatment of cervical1-2 epidural neurilemmoma]

OBJECTIVE

To explore the minimally invasive surgical method for cervical1-2 epidural neurilemmoma.

METHODS

The clinical features, imaging characteristics and surgical methods of 63 cases of cervical1-2 epidural neurilemmoma from July 2010 to December 2018 were reviewed and analyzed. Pain and numbness in occipitocervical region were the common clinical symptoms. There were 58 cases with pain, 30 cases with numbness, 3 cases with limb weakness and 2 cases with asymptomatic mass. Magnetic resonance imaging (MRI) showed that the tumors located in the cervical1-2 epidural space with diameter of 1-3 cm. The equal or slightly lower T1 and equal or slightly higher T2 signals were found on MRI. The tumors had obvious enhancement. Individualized laminotomy was performed according to the location and size of the tumors, and axis spinous processes were preserved as far as possible. Resection of tumor was performed strictly within the capsule.

RESULTS

Total and subtotal resection of tumor were achieved in 60 and 3 cases respectively, and no vertebral artery injury was found. The operation time ranged from 60 to 180 minutes, with an average of 92.83 minutes. The hospitalization time ranged from 3 to 9 days, with an average of 5.97 days. All tumors were confirmed as neurilemmoma by pathology. There was no postoperative infection or cerebrospinal fluid leakage. There was no new-onset dysfunction except 9 cases of numbness in the nerve innervation area. The period of follow-up ranged from 6 months to 8 years (median: 3 years). All the new-onset dysfunction recovered completely. Pain disappeared in all of the 58 patients with pain. Numbness recovered completely in 27 patients while slight numbness remained in another 3 patients. Three patients with muscle weakness recovered completely. The spinal function of all the patients restored to McCormick grade Ⅰ. No recurrence was found on MRI. No cervical spine instability or deformity was found on X-rays.

CONCLUSION

It is feasible to resect cervical1-2 epidural neurilemmoma by full use of the anatomical space between atlas and axis and individual laminotomy. It is helpful to prevent cervical instability or deformity by minimizing the destruction of cervical2 bone and preserving normal muscle attachment to cervical2 spinous process. Strict intracapsular resection can effectively prevent vertebral artery injury.

Immediate postoperative MRI findings after lumbar decompression surgery: Correlation of imaging features with clinical outcome

An understanding of the common MRI findings observed after decompression surgery is important. However, to date, no study addressing this has been published. The aim of this study was to analyze and describe the immediate postoperative MRI findings after lumbar decompression surgery. We retrospectively analyzed the immediate postoperative MRIs of 121 consecutive patients who underwent lumbar decompression surgery between July 2017 and June 2018. Changes in stenosis at the decompressed and adjacent levels, epidural fat edema, epidural and subdural fluid collections, nerve root swelling, facet joint effusions, intervertebral disc signal, and paravertebral muscle edema were correlated with clinical characteristics. Both groups had reduced central canal stenosis postoperatively (p < 0.001) but worsened stenosis at adjacent segments. Fluid collection, hemorrhagic or non-hemorrhagic, at the laminectomy site was the commonest finding (one-level: 73.8%, two-level: 88.5%), with a higher percentage of severe central canal compromise in the two-level decompression group (p = 0.003). Other postoperative MRI findings, such as epidural fat edema, nerve root swelling, subdural fluid collection, and facet joint effusion, were noted without statistical significance. In conclusion, even with successful decompression for lumbar canal stenosis, increased central canal stenosis at adjacent segments is common on immediate postoperative MRI scans, showing no statistically significant correlation with the immediate postoperative outcome. Postoperative fluid collection at the laminectomy site is the commonest imaging finding, and higher rates of hemorrhagic fluid and more severe central canal compromise occur in two-level decompression, but rarely cause clinical problems.

Microsurgical treatment for spinal epidural angiolipomas

Spinal epidural angiolipomas are rare lesions composed of mature lipomatous and angiomatous elements. In this paper, the authors review a surgical series of ten patients with epidural angiolipomas. All patients had performed preoperative and postoperative magnetic resonance imaging. The diagnosis of angiolipoma was based on pathology. All the follow-up data were obtained during office visits. There were 5 males and 5 females with a mean age of 53.6 years. One tumor was located in the cervicothoracic, six in the thoracic, and three in the lumbar spine. The most common symptom was progressive motor deficit. Gross total resection of the tumor was achieved in nine cases, and subtotal resection was obtained in one case. No recurrence or regrowth of the residual tumor was observed during a follow-up period of 50.8 months. At the last follow-up, 90% of patients experienced improvement in the neurological function. Epidural angiolipomas are benign but clinically progressive lesions. Early surgery should be performed to prevent irreversible neurological deficits. Postoperative radiotherapy is not recommended. The risk of long-term recurrence/regrowth of the lesions is low, and a good clinical outcome after total or subtotal removal can be expected.

[Epidural lipomatosis : management proposal]

Epidural lipomatosis is a rare condition characterized by excessive accumulation of normal fat in the epidural space. This paper presents the results of a retrospective study of the charts of 20 patients. The 20 patients - 17 men and 3 women - were on average 64 years old. They suffered from radiculopathy and/or neurogenic claudication. Lipomatosis was idiopathic in 6 patients and secondary in 14 patients. Lipomatosis was MRI grade 2 in 30 % of cases and grade 3 in 70 % of cases. The patients have all been improved thanks to decompressive surgery by laminectomy and resection of epidural fat. According to our experience and to the literature, surgical decompression is an effective and safe procedure for patients with symptomatic lumbar epidural lipomatosis in case of failure of conservative treatment or in case of neurological deficits. We present a decision tree that can help in the management of this disease.

Clinical Implications of the Epidural Fat Thickness in the Management of Lumbar Spinal Stenosis

OBJECTIVE

Lumbar epidural lipomatosis is a rare condition defined as the excessive accumulation of epidural fat (EF). We herein investigated the indicators of the posterior compression factors, EF and yellow ligament, to identify the clinical features of lumbar epidural lipomatosis.

METHODS

Five hundred consecutive patients who underwent posterior lumbar decompression surgery for lumbar spinal stenosis (LSS) were retrospectively reviewed. The EF/SC-L index (the ratio of the anteroposterior length of the EF to that of the spinal canal [SC]) was evaluated at the spinal level that exhibited maximum dural tube compression. The participants were divided into 3 groups: grade I, EF/SC-L index ≤50%; grade II, EF/SC-L index 51%-74%; grade III, EF/SC-L index ≥75%. EF/SC-A (the ratio of the cross-sectional area of EF to that of SC) and YL/SC-A (the ratio of the cross-sectional area of yellow ligament [YL] to that of SC) were calculated. The clinical outcomes were assessed according to the Japan Orthopaedic Association scale for lumbar disease.

RESULTS

EF/SC-L exhibited a significantly positive correlation with EF/SC-A (r = 0.82, P < 0.001), and a negative correlation with YL/SC-A (r = -0.71, P < 0.001). The Japan Orthopaedic Association score recovery rate was 56.7 ± 22.6 in the case-matched control group, 34.5 ± 31.2 in the grade II group (P < 0.001), and 39.6 ± 24.9 in the grade III group (P = 0.032).

CONCLUSIONS

The EF/SC-L index is a simple and reliable indicator to quantitatively evaluate posterior compression in patients with LSS. As the accumulation of EF is associated with worse operative outcomes, the EF/SC-L index should be considered when planning lumbar decompression surgery for patients with LSS.

Spinal Epidural Lipomatosis with Osteoporotic Vertebral Fractures Presenting as Acute Thoracic Myelopathy in a 33-Year-Old Man with Cushing Disease

BACKGROUND

Steroid-related spinal epidural lipomatosis (SEL) is a well-known condition most commonly encountered in patients taking chronic steroid medications. Endogenous Cushing syndrome is a rare cause of SEL. The authors report an unusual presentation of acute thoracic myelopathy due to SEL with osteoporotic vertebral compression fractures in a patient with Cushing disease.

CASE DESCRIPTION

A 33-year-old man presented with thoracic myelopathy due to SEL and multiple vertebral compression fractures. He had Cushingoid clinical features, and investigations revealed a pituitary microadenoma as the cause of hypercortisolism. The diagnosis was missed on multiple occasions before the onset of paraparesis. The patient was treated with urgent thoracic laminoplasty followed by transsphenoidal surgery on the same day. Although normalization of the serum cortisol levels was delayed by 6 months, he had a complete neurologic recovery and remains symptom free at 2 years follow-up.

CONCLUSIONS

This is a rare presentation of Cushing disease and has been reported only twice before in the 1990s. This case highlights the need to keep a high degree of suspicion for development of thoracic myelopathy in a patient with Cushing syndrome who develops thoracic compression fractures associated with SEL. Early recognition of this clinical association and addressing the primary endocrine problem urgently could have prevented spinal cord involvement and the subsequent spine surgery. This scenario is also documented in previous published case reports of this association where the diagnosis of Cushing syndrome has been revealed retrospectively after the development of neurologic symptoms.

Nonfusion Muscle-Sparing Technique to Treat Long-Segment Thoracolumbar Extradural Arachnoid Cyst in a Child: A Case Report and Review of the Literature

BACKGROUND

Spinal extradural arachnoid cyst is an uncommon cause of spinal cord compression. It results from a small dural defect that leads to cerebrospinal fluid (CSF) accumulation in the cyst and subarachnoid space, and the cyst can compress the spinal cord and nerve roots. Surgery is the treatment of choice in symptomatic patients, and most cases have an immediately satisfying outcome after surgery.

CASE DESCRIPTION

A 10-year-old Thai boy presented with progressive weakness in both legs. Magnetic resonance imaging (MRI) demonstrated a giant cystic lesion 23 cm in length from T1-L2 level. To our knowledge, this is the longest arachnoid cyst that has been reported in children. The operation included unilateral paraspinal muscle dissection with spinous process translation techniques, T1-L4 laminectomy, total cyst excision, and dural defect repair at the T4 level. The symptoms were fully resolved within 2 months after surgery. However, thoracic kyphosis was slightly increased, but the patient still has a normal sagittal profile.

CONCLUSIONS

Spinal arachnoid cyst is rare, especially in children. Early diagnosis and treatment are essential for improving the chance of full recovery, and for avoiding complication and irreparable defect. Total cyst removal with dural repair remains the best treatment alternative; however, potential complications, especially spinal malalignment after extensive laminectomy, must be considered. Postoperative MRI showed normal CSF flow and no spinal cord compression. The muscle-sparing technique with multiple-level laminectomy without spinal fusion that we used in this case provided a satisfying outcome.

Thoracic myelopathy caused by an extremely rare aberrant epidural ligament: A case report

RATIONALE

The meningovertebral ligaments are a group of tissues that connect the dura and the vertebral bone. Abnormal fibrous ligaments in the canal space, which are essentially different from these ligaments, have been identified and their presence very rarely results in spinal disorder.

PATIENT CONCERNS

A 20-year-old Mongolian woman had developed persistent headache at 15 years of age. She then became unable to run fast when she was 19 years old and had progressively declining ability to move. She complained of back pain and unstable gait 6 months prior to presentation. Physical examination revealed exaggerated deep tendon reflexes in the lower extremities and decreased proximal leg muscle strength bilaterally.

DIAGNOSES

Magnetic resonance imaging (MRI) revealed abnormal bands compressing the spinal cord at the T10/11 level, with large epidural lipomatosis dorsal to the dural tube.

INTERVENTION

To decompress the cord, posterior laminectomy for T3-L3 and removal of the heterotopic ligaments were performed with T8-L1 posterior fusion.

OUTCOMES

Sufficient decompression of the cord was noted on postoperative MRI at the affected segments. The patient could subsequently walk without a cane and headache resolved immediately after the operation.

LESSONS

The presence of an aberrant epidural band is a rare pathologic state that often coexists with a surrounding lipomatosis and can lead to spinal cord compression. Removal of the band is a promising treatment for myelopathy caused by the compressive lesion.

Transforaminal Epiduroscopy in Patients with Failed Back Surgery Syndrome

BACKGROUND

Epiduroscopy is a useful diagnostic and therapeutic tool for managing failed back surgery syndrome (FBSS). The conventional approach is via either the sacral hiatus or the interlaminar. Major causes of FBSS include epidural fibrosis, disc herniation, and stenosis. When these problems are located at the intervertebral foramen level, it can be difficult to reach the lateral recess and the foramen with the epiduroscope. Transforaminal epiduroscopy could be a useful alternative approach in patients with FBSS located at the foraminal level.

OBJECTIVE

We present a new procedure for lumbar epiduroscopy via a transforaminal approach and its application in patients with FBSS. The technique is described and long-term results are reported.

STUDY DESIGN

This study used a single-arm prospective observational design.

SETTING

The research took place at the University Hospital in Spain.

METHODS

Patients with FBSS suffering severe chronic radicular pain (Numeric Rating Scale [NRS-11] > 7) who had not responded to other treatments were included. Selective root stimulation during a pulsed radiofrequency procedure confirmed the origin of pain by means of an exact reproduction of typical pain. Transforaminal epiduroscopy was performed at the affected level. The severity of fibrosis observed was recorded. The NRS-11 score was reevaluated at 1, 6, and 12 months after the procedure. Any complications related to the treatment were recorded.

RESULTS

Twenty-four patients were included. The mean number of back surgeries was 1.66 (range, 1-5). The basal NRS-11 score was 7.83 (0.14); at 1 month, 3.66 (0.38) (P < 0.001); at 6 months, 4.46 (0.48) (P < 0.01); and at 1 year after treatment, 4.17 (0.51) (P < 0.01). Most patients (54%; 95% CI, 34%-74%) obtained > 50% pain reduction on the NRS-11, maintained during a 1-year follow-up period. No major complications were registered.

LIMITATIONS

The research was limited by the lack of a control group.

CONCLUSIONS

We have described a new procedure for epiduroscopy via the transforaminal approach. It is a useful and safe approach to managing FBSS at the foraminal level and shows better long-term results than other endoscopic procedures.

KEY WORDS

Epidural, epiduroscopy, chronic pain, spinal cord, back surgery.

Is a Retrolaminar Approach to the Thoracic Paravertebral Space Possible?: A Human Cadaveric Study

BACKGROUND AND OBJECTIVES

The retrolaminar block (RB) is used for truncal analgesia, but its mechanism of neural blockade remains obscure. We sought to learn the pattern of local anesthetic spread after thoracic RB using cadaveric models.

METHODS

In 8 fresh cadavers, an ultrasound-guided T4 RB was performed with 20 mL of methylene blue 1% and bupivacaine 0.5%. For comparison, an RB at T9 in 1 cadaver and a T4 thoracic paravertebral block in another cadaver were performed. Subsequently, posterior and anterior thoracic dissections were performed to examination where the dye spread.

RESULTS

After T4 RB, dye was noted to spread in the ipsilateral retrolaminar plane (all 8 cadavers, median cephalad spread 3.5 cm, caudad spread 10.7 cm, lateral spread 2.5 cm), the contralateral retrolaminar plane (6 cadavers), the paravertebral space (5 cadavers, median of 3 segments, T3-T5), the intercostal space (5 cadavers, median of 3.5 cm laterally), the T4 epidural space (6 cadavers), and the intervertebral foramina (4 cadavers, median of 2 segments, T4-T5). After T9 retrolaminar injection, dye was noted in the ipsilateral retrolaminar plane (5.5 cm cephalad, 13.5 cm caudad, and 2.5 cm lateral), the contralateral retrolaminar plane, and the epidural space. Dye after T4 traditional paravertebral block spread to T1-T6 paravertebral space with 15-cm lateral spread.

CONCLUSIONS

Injectate spread to the paravertebral space, epidural space, intercostal space, and intervertebral foramina is possible in the RB but is quite variable. In comparison to the thoracic paravertebral block, injectate spread within the paravertebral space is more limited.

Feasibility of Percutaneous Robot-Assisted Epiduroscopic System

BACKGROUND

Endoscopy has replaced open surgery, especially in spinal surgery. Among them, image-guided epiduroscopy allows pain generators to be identified, including epidural adhesion, fibrotic tissues, root compression, and spinal stenosis. However, the heavy lead apron worn by pain physicians to avoid exposure to radiation can induce occupational hazards, such as orthopedic complications and radiation-induced cancer. Hence, we developed a robotic system to address these problems.

OBJECTIVE

The aim of the study was to evaluate the feasibility of a robot-controlled epiduroscopic system.

STUDY DESIGN

In vivo animal experiment.

SETTING

University in Republic of Korea.

METHODS

The robot-controlled epiduroscopic system was developed using the open architecture robot system (The Raven Surgical Robotic System, CITRIS, Berkley, CA, USA). The robotic system consists of a lab-made epiduroscope, steering section, robotic arm, and manipulator. For the in vivo study, 2 Yorkshire pigs were used to simulate an epiduroscopic procedure with the robotic system.

RESULTS

The insertion and steering of the catheter was performed safely, and epiduroscopic visualization was obtained without side effects. There were no device-related complications. Radiation exposure for the primary operator was 80% lower than the levels found during conventional epiduroscopic procedures. All live pigs showed normal behavior without any signs of pain. The mean time to reach the target region was less than 8 minutes.

LIMITATIONS

The epiduroscopic procedure was performed on pigs and not on humans. The dimensions of the spinal canal of pigs cannot compare to those of humans.

CONCLUSIONS

We demonstrated the feasibility of the robot-assisted epiduroscopic system.

KEY WORDS

Epiduroscopy, robotic system, spine, pig, animal model.

Ambulation and survival following surgery in elderly patients with metastatic epidural spinal cord compression

BACKGROUND AND CONTEXT

Metastatic epidural spinal cord compression (MESCC) is a disabling consequence of disease progression. Surgery can restore or preserve physical function, improving access to treatments that increase duration of survival; however, advanced patient age may deter oncologists and surgeons from considering surgical management.

PURPOSE

Evaluate the duration of ambulation and survival in elderly patients following surgical decompression of MESCC.

STUDY DESIGN/SETTING

Retrospective file review of a prospective database, under institutional review board (IRB) waiver of informed consent, of consecutive patients treated in an academic tertiary care medical center from August 2008 to March 2015.

PATIENT SAMPLE

Patients ≥65 years presenting neurological and/or radiological signs of cord compression because of metastatic disease, who underwent surgical decompression.

OUTCOME MEASURES

Duration of ambulation and survival.

METHODS

Patients underwent urgent multidisciplinary evaluation and surgery. Ambulation and survival were compared with age, pre-, and postoperative neurological (American Spinal Injury Association [ASIA] Impairment Scale [AIS]) and performance status (Karnofsky Performance Status [KPS]), and Tokuhashi Score using Kruskal-Wallis and Wilcoxon signed rank tests, Pearson correlation coefficient, Cox regression model, log-rank analysis, and Kaplan-Meier analysis.

RESULTS

Forty patients were included (21 male, 54%; mean age 74 years, range 65-87). Surgery was performed a mean 3.8 days after onset of motor symptoms. Mean duration of ambulation and survival were 474 (range 0-1662) and 525 days (range 11-1662), respectively; 53% of patients (21 of 40) survived and 43% (17 of 40) retained ambulation for ≥1 year. There was no significant relationship between survival and ambulation for patients aged 65-69, 70-79, or 80-89 years, although Kaplan-Meier analysis suggested stratification. There was a significant relationship between duration of ambulation and pre- and postoperative AIS (p=.0342, p=.0358, respectively) and postoperative KPS (p=.0221). Tokuhashi score was not significantly related to duration of survival or ambulation, and greatly underestimated life expectancy in 22 of 37 (59%) patients with scores 0-11.

CONCLUSIONS

Decompressive surgery led to marked improvement in neurological function and performance status. More than 50% of patients survived for >1 year, some for 3 years or more after surgery.

Intradural disc herniation: how I do it

BACKGROUND

Intradural disc herniation is a rare phenomenon in spine surgery. Diagnosis is difficult despite current neuroradiologic imaging techniques.

METHOD

We present a case of a 59-year-old man with lumbar and radicular pain and a recurrent lumbar herniation. A laminectomy was performed after no clear disc herniation in the epidural space was found and an intradural mass was palpable. A durotomy showed an intradural disc fragment that was removed, followed by an arthrodesis.

CONCLUSION

Only intraoperative findings lead to a definitive diagnosis for intradural herniation. A durotomy needs to be performed. In this case, an arthrodesis was necessary to avoid complications of segmental instability.

Epiduroscopic laser neural decompression as a treatment for migrated lumbar disc herniation: Case series

OBJECTIVE

Epiduroscopic laser neural decompression (ELND) is one of the more invasive techniques for managing patients with herniated lumbar disc. However, ELND can be used to treat, and diagnose the epidural pathology; indications for ELND remain controversial, especially, when applied in cases of large disc extrusion and migrated disc. This paper reports cases of patients that were satisfied with the ELND procedure for migrated lumbar disc herniation.

METHODS

We reviewed the medical records of patients that received ELND for migrated lumbar disc in an outpatient clinic. The patients complained of low back pain with radicular pain with an intensity over 5 on a numeric rating scale (NRS) that had persisted for over 1 month. The Magnetic resonance imaging (MRIs) showed migrated lumbar disc herniation, and patients opted for ELND because they had previously experienced nerve blocks, and did not want to receive open surgery for their pain, even after the limitations of ELND were explained.

RESULTS

Patients reported that their pain was dramatically reduced, and other discomfort symptoms, such as numbness, were also reduced after the procedure. In follow-up, all of the patients were satisfied with the results.

CONCLUSION

We applied the ENLD procedure to mechanically, remove disc material that compressed the spinal nerve, and the patients were satisfied, and reported symptom relief. ELND was a sufficient treatment approach for lumbar migrated herniated disc for patients who did not want to undergo open spine surgery.

The role of pegaptanib sodium in the suppression of epidural fibrosis in a postlaminectomy rat model

OBJECTIVE

Spinal epidural fibrosis is a clinical condition that develops after laminectomy and can compress the spine. Many agents have been tried for the treatment, but none has entered clinical use at present. Pegaptanib sodium is an antiangiogenetic drug that prevents the development of new vessels and thus adhesion by inhibiting the effect of VEGF.

MATERIAL AND METHOD

20 Wistar rats were used in this study. The rats were divided into 2 different groups as the control and pegaptanib sodium group. Three levels of laminectomy were performed. Only laminectomy was performed in the control group. A cotton ball soaked with 3 mg/kg Pegaptanib sodium diluted 1: 10 with 0.9 % NaCl was topically applied to the dura in the surgical field for 5 minutes in the pegaptanib sodium group. The rats were sacrificed 3 weeks later and histopathologically examined. The epidural fibrosis was graded.

RESULTS

The epidural fibrosis grade in the pegaptanib sodium was significantly lower than in the control group c2 = 11,65; (p = 0.004)CONCLUSION: Pegaptanib sodium blocked the VEGF through its anti-VEGF effect and decreased spinal epidural fibrosis in rats that had undergone laminectomy (Tab. 2, Fig. 3, Ref. 53).

Endoscopic Epidural Laser Decompression Versus Transforaminal Epiduroscopic Laser Annuloplasty for Lumbar Disc Herniation: A Prospective, Randomized Trial

BACKGROUND

Lumbar radicular pain often results from lumbar disc herniation, spinal stenosis, or degenerative spondylolisthesis. Minimally invasive disc decompression procedures, such as nucleo-annuloplasty or epiduroscopic neural decompression by laser, have been devised to treat such pain.

OBJECTIVE

The short-term outcomes of disc decompression by endoscopic epidural laser decompression (EELD) or transforaminal epiduroscopic laser annuloplasty (TELA) were compared in patients with lumbar radicular pain due to disc herniation.

STUDY DESIGN

A randomized, prospective trial.

SETTING

The Department of Anesthesiology and Pain Medicine at Spine Health Wooridul Hospital in Daegu, Korea.

METHODS

A total of 97 patients were enrolled in this study; 48 patients underwent EELD and 49 underwent TELA. The pain relief was evaluated at baseline and at 1, 3, and 6 months post-procedure via the numeric rating scale (NRS). The Oswestry Disability Index (ODI) was recorded at baseline and at the final follow-up. Postoperative wound pain was assessed over a 24-hour period. Complications and side effects were also recorded, as were operative times (from local anesthetic infiltration at entry sites to suturing of skin).

RESULTS

At post-treatment months 1, 3, and 6 the mean pain scores of patients were significantly lower (relative to pre-treatment baseline) regardless of the procedure used. However, the mean pain scores did not differ significantly by procedure (EELD vs TELA). As well, the number of patients who obtained relief from their pain and needed analgesics was not statistically significant. The irrigation volume was significantly higher in the TELA group. Two patients undergoing TELA procedures experienced headache during the procedures; however, no serious complications such as bleeding, dural/neural injuries, or infection were recorded for either group.

LIMITATION

The observed significant reductions in pain (from baseline) lacked secondary outcome substantiation and given the mid follow-up period, no long-term follow-up results were monitored.

CONCLUSION

Both EELD and TELA provide similar outcomes and are reasonable treatment options for carefully selected patients with lower back or radicular pain.

KEY WORDS

Epiduroscopy, laser, annuloplasty, disc, herniation, TELA.

Factors Associated with Successful Responses to Transforaminal Balloon Adhesiolysis for Chronic Lumbar Foraminal Stenosis: Retrospective Study

BACKGROUND

Recently, transforaminal balloon adhesiolysis was introduced to manage patients with chronic radicular pain occurring with or without low back pain. However, the factors associated with successful responses to transforaminal balloon adhesiolysis are not known.

OBJECTIVE

To evaluate the factors associated with successful responses to transforaminal balloon adhesiolysis for chronic lumbar spinal stenosis.

STUDY DESIGN

This is a retrospective observational study.

SETTING

A single pain clinic of tertiary medical center in Seoul, Republic of Korea.

METHODS

From January 2013 to December 2014, a retrospective review of 199 patients with chronic lumbar foraminal stenosis, who were scheduled for transforaminal balloon adhesiolysis, was performed. Patients were considered successful responders if they showed either of the following: 1) a decrease of more than 50% on the numerical rating scale or 2) a decrease of more than 30% on the numerical rating scale and improved functional status 3 months after transforaminal balloon adhesiolysis. Logistic regression analysis was performed to determine the factors associated with successful responses to this surgical procedure.

RESULTS

Three months after the transforaminal balloon adhesiolysis, 49.4% of patients were considered successful responders. Multivariate logistic regression analysis showed that factors other than degenerative disc herniation were independently associated with successful responses 3 months after this surgical procedure (odds ratio = 0.327; 95% confidence interval = 0.129 - 0.827; P = 0.018).

LIMITATIONS

The definition of successful response used in this study differed from the ones used in previous studies; a different definition may have led to different results. Further, the effects of other factors (ballooning, drugs, and saline washes) could not be excluded from our study. In addition, the correct method of assessing functional status, the Oswestry Disability Index, could not be used in this study; hence, the final results may have been affected.

CONCLUSION

These results suggest that transforaminal balloon adhesiolysis can successfully lead to improvement of symptoms in patients with chronic lumbar foraminal stenosis caused primarily by degenerative disc herniation.Institutional Review Board (IRB) approval number: 2016-0228.Key words: Balloon, epidural adhesiolysis, chronic pain, radicular pain, lumbar spine, foraminal stenosis, degenerative disc.

Epidural Spinal Stimulation to Improve Bladder, Bowel, and Sexual Function in Individuals With Spinal Cord Injuries: A Framework for Clinical Research

While some recent studies that apply epidural spinal cord stimulation (SCS) have demonstrated a breakthrough in improvement of the health and quality of the life of persons with spinal cord injury (SCI), the numbers of people who have received SCS are small. This is in sharp contrast to the thousands of persons worldwide living with SCI who have no practical recourse or hope of recovery of lost functions. Thus, the vision is to understand the full potential of this new intervention and to determine if it is safe and effective in a larger cohort, and if it is scalable so that it can be made available to all those who might benefit. To achieve this vision, the National Institute of Biomedical Imaging and Bioengineering called for and organized a consortium of multiple stakeholder groups: foundations addressing paralysis, federal and public agencies, industrial partners, academicians, and researchers, all interested in the same goal. Based on input from consortium participants, we have reasoned that a first step is to define a scalable SCS approach that is effective in restoring lost autonomic physiology, specifically bladder, bowel, and sexual function. These functions are most critical for improving the quality of life of persons living with SCI. This report outlines a framework for conducting the research needed to define such an effective SCS procedure that might seek Food and Drug Administration approval and be implemented at the population level.

Idiopathic Spinal Epidural Lipomatosis in the Lumbar Spine

Overgrowth of epidural fat, known as spinal epidural lipomatosis (SEL), can cause symptomatic compression of the spinal cord, conus medullaris, or cauda equina. Suggested predisposing factors such as obesity, steroid use, and diabetes mellitus have been based on a few reported cases, many of which were not surgically confirmed. There is a paucity of epidemiological data in surgically confirmed cases for this disorder. The purpose of this independently reviewed, retrospective, matched cohort analysis was to compare the demographics and incidence of comorbidities of patients who underwent lumbar decompression for SEL vs degenerative stenosis without SEL. Two surgeons' databases were reviewed to identify patients older than 18 years who underwent decompression surgery for magnetic resonance imaging-verified, symptomatic lumbar SEL. A matched control group comprised an equal number of patients with degenerative stenosis (n=14). Demographic data, body mass index, symptom type/duration, comorbidities, complications, treatment history, and associated pathology were collected from medical records. Previously suggested risk factors, such as obesity, endocrinopathy, and epidural steroid injections, were not significantly different between the SEL and control groups. Furthermore, there were no differences in operative times, complications, or blood loss. The only noted difference between the 2 groups was the preoperative duration of symptoms, on average double in patients with SEL. This series represents the largest of its kind reported to date. Because symptom duration was the only difference noted, it is postulated to be the result of lack of awareness of SEL. Future prospective study in a larger group of patients is warranted. [Orthopedics. 2016; 39(3):163-168.].

The Extent of Tissue Damage in the Epidural Space by Ho / YAG Laser During Epiduroscopic Laser Neural Decompression

BACKGROUND

Lasers have recently become very useful for epiduroscopy. As the use of lasers increases, the potential for unwanted complications with direct application of laser energy to nerve tissue has also increased. Even using the lowest laser power to test for nerve stimulation, there are still risks of laser ablation. However, there are no studies investigating tissue damage from laser procedures in the epidural space.

OBJECTIVE

This is a study on the risks of Ho/YAG laser usage during epiduroscopy.

STUDY DESIGN

Observatory cadaver study.

SETTING

Department of anatomy and clinical research institute at the University Hospital.

METHODS

We used 5 cadavers for this study. After removing the dura and nerve root from the spinal column, laser energy from a Ho/YAG laser was applied directly to the dura and nerve root as well as in the virtual epidural space, which mimicked the conditions of epiduroscopy with the dura folded. Tissue destruction at all laser ablation sites was observed with the naked eye as well as with a microscope. Specimens were collected from each site of laser exposure, fixed in 10% neutral formalin, and dyed with H/E staining.

RESULTS

Tissue destruction was observed in all laser ablation sites, regardless of the length of exposure and the power of the laser beam.

LIMITATIONS

A cadaver is not exactly the same as a living human because dura characteristics change and tissue damage can be influenced by dura thickness according to the spinal level.

CONCLUSION

Even with low power and short duration, a laser can destroy tissue if the laser beam makes direct contact with the tissue.

Investigation of meningomyovertebral structures within the upper cervical epidural space: a sheet plastination study with clinical implications

BACKGROUND CONTEXT

Over the past two decades, soft-tissue structures communicating with the dura mater within the epidural space have become the focus of many anatomical and histopathologic studies. The relationship between these bridging structures has yet to be evaluated in situ.

PURPOSE

This is the first study that used E12 sheet plastination to investigate the epidural space of the upper cervical spine in situ and its associated bridging structures. Given the complexity of this space, this study may prove useful to clinical anatomists and surgeons who operate within this region.

STUDY DESIGN

Anatomical and microscopic analyses of structures that communicate with the dura mater within the upper cervical region were carried out.

METHODS

Gross dissection in conjunction with microscopy was used to evaluate bridging communications of the upper cervical spine in 10 cadavers. To evaluate the in situ arrangement of these structures, E12 sheet plastination was used on 13 cadavers.

RESULTS

In all 23 specimens, suboccipital fascia coalesced with the dorsal meningovertebral ligament of the atlas, and inserted directly into the posterior surface of the dura as a single but separable laminar layer. At the level of the atlantoaxial interspace, suboccipital fasciae combined and coalesced with the dorsal meningovertebral ligament of the atlas and the axis. These structures inserted into the posterior surface of the dura mater as a single but separable layer. Microscopy validated these findings and E12 sheet plastination revealed the in situ organization of these soft-tissue structures. E12 sheet plastination also provided new information on dural arrangement at the craniocervical junction, which was observed to be composed of periosteum from the occiput but consisted mainly of deep fascia from the rectus capitis posterior minor.

CONCLUSIONS

E12 sheet plastination has provided in situ visualization of bridging structures within the cervical epidural space and offers new insight into these structures, as well as the composition and arrangement of the posterior atlantooccipital membrane and cerebrospinal dura at the craniocervical junction. This study aims to expand on the anatomical understanding of the upper cervical region while defining structures that may reduce neurosurgical complications, and aid in the understanding of the pathophysiology of certain neurogenic disorders.

Reduction of epidural fibrosis and dural adhesions after lamina reconstruction by absorbable cement: an experimental study

BACKGROUND CONTEXT

Post-laminectomy epidural fibrosis complicates revision spine surgery and is implicated in cases of "failed back syndrome." Several materials have been used to minimize epidural fibrosis with varying results.

PURPOSE

The aim of this study was to examine the impact of reconstruction of laminectomy site with a type of absorbable cement (Jectos) to reduce epidural fibrosis.

STUDY DESIGN

This investigation is an experimental controlled study, which is designed to evaluate the preventive effects of laminectomy site reconstruction in rat laminectomy model.

METHODS

Twenty wistar rats were included in this study and divided randomly to two equal groups, namely, subject and control. In both groups, laminectomy was performed in L2 and L4 levels. Control group received no additional treatment. In the subject group, L4 levels were reconstructed by Jectos and L2 levels were non-reconstructed as internal controls. Six months after surgery the rats were sacrificed and the dural adhesion and epidural fibrosis were evaluated macroscopically and microscopically. The study was financially supported by Brain and Spinal Cord Injuries Repair Center. None of the authors have any conflict of interest.

RESULTS

Non-reconstructed levels in both groups showed dense epidural fibrosis with marked dural adherence. L4 reconstructed levels in subject group showed reduced epidural fibrosis macroscopically (p=.024) and microscopically (p=.041). No foreign body reaction or ossification occurred at reconstructed sites.

CONCLUSIONS

In the present study, lamina reconstruction with absorbable cement was a safe method that significantly reduced post-laminectomy epidural fibrosis and dural adhesions in rat laminectomy model.

Evaluation of prognostic predictors of percutaneous adhesiolysis using a Racz catheter for post lumbar surgery syndrome or spinal stenosis

BACKGROUND

Percutaneous adhesiolysis (PA) is considered to be a reasonable nonoperative treatment for herniation of intervertebral disc (HIVD), spinal stenosis, and post-lumbar-surgery syndrome (PLSS). The success of PA depends on the removal of epidural fibrosis and drug delivery to the target region. However, prognostic predictors of the effects of PA are not well known.

OBJECTIVE

The aim of this study was to evaluate prognostic predictors of PA using a Racz catheter for patients with PLSS or spinal stenosis.

STUDY DESIGN

Retrospective assessment.

METHODS

PA using a Racz catheter was performed on 78 patients. We assessed the effectiveness of PA at pretreatment, 2 weeks, 3 months, and 6 months following the procedure. Effectiveness was defined as a 50% or more reduction of the Numeric Rating Scale (NRS) for back and leg pain or a 40% or more reduction of the Oswestry Disability Index (ODI) following the procedure. Data collected for each patient included age, gender, BMI, grade and location of stenosis in magnetic resonance imaging (MRI), symptom durations, and history of previous lumbar surgery. The adjusted odds ratios (OR) and 95% confidence intervals (CI) for each variable were analyzed by logistic regression.

RESULTS

PA using a Racz catheter was more effective in patients with no previous lumbar surgery (OR, 7.426; 95% CI, 1.820-30.302; P = 0.005) or root compression with HIVD or foraminal stenosis (OR, 5.479; 95% CI, 1.137-26.391; P = 0.036). Other included factors were not related to PA effectiveness.

LIMITATIONS

The number of patients examined in this study was relatively small.

CONCLUSION

Good prognostic predictors were identified as no previous lumbar surgery or root compression with HIVD or foraminal stenosis. These results are expected to contribute to the establishment of indications for PA.

Evaluation of interaction between a spinal cord stimulator and implanted cardioverter-defibrillator in a swine model

BACKGROUND

Spinal cord stimulators (SCS) have been used for many years to treat a myriad of chronic pain conditions using electrical signals to diminish the perception of a painful stimulus. Because of the electrical nature of the devices, there is a concern about the potential for electromagnetic interaction between the device and lifesaving cardiac implantable cardioverters-defibrillators (ICVD).

OBJECTIVE

The purpose of this study was to use a swine model to evaluate the potential for interaction between an implanted SCS and ICVD using the closest possible proximity, highest stimulation settings, and most sensitive ICVD settings.

METHODS

A pig was anesthetized and subsequently an ICVD and ICVD lead (Cogni 100-D and Endotak Reliance®, Boston Scientific, Natick, MA) were placed into the right prepectoral region and the right ventricle, respectively. An SCS (50 cm linear ST Precision Plu octad electrode lead [Boston Scientific, Valencia, CA] with 3 mm wide contacts spaced one mm apart- ) was implanted using fluoroscopic guidance into the posterior epidural space. Remote interrogation and programming of the ICVD were performed while the SCS lead was placed in as close proximity as possible, using fluoroscopy to guide the final position of the SCS electrode. After confirming that both systems were working, appropriately 9 stimulating configurations of varying current, pulse width, and frequency, including maximal settings, were delivered through the SCS. The effects on the ICVD were recorded at 2 sensitivity settings.

RESULTS

None of the tested SCS configurations caused interference with the proper functioning of the ICVD.

LIMITATIONS

The anatomical proximity of the posterior epidural space and right ventricle of the swine is different from humans. While the entire pacer, including generator, was imbedded in a subcutaneous pocket, an implantable pulse generator for the SCS was not implanted, which did not allow us to study if any damage or a resetting of settings had occurred to the generator. Only one manufacturer was used in this study. Also, this study was performed in an anesthetized pig and the anatomical positions remained static. Realistically, changes in position of the devices would occur in patients who perform activities of daily living, and this can potentially shorten the distance between the 2 leads causing adverse interaction.

CONCLUSION

This study clearly demonstrated the feasibility of the 2 devices coexisting and functioning appropriately in an animal model using an ICVD and SCS donated by Boston Scientific. Further studies are needed to elucidate restrictions, optimal settings and parameters in a human setting.

Primary primitive neuroectodermal tumor within the spinal epidural space: report of a case and review of the literature

Primary intraspinal primitive neuroectodermal tumors (PNETs) are rare tumors and a have poor prognosis. In reviews of the literature, it is seen that primary intraspinal PNETs may arise at all levels of the spine and may be intramedullary, intradural-extramedullary, or epidural. Spinal epidural location of PNET is extremely rare and out of 22 cases of primary spinal PNETs reported to date, only two were epidural. Tumors within the epidural space of the spinal canal are most often metastatic neoplasms from different primary sites. Here we report a case of primary extradural PNET located in the thoracic spine in a 16-year-old boy and review the relevant literature.

Vertebroplasty for the compression of the dorsal root ganglion due to spinal metastasis

BACKGROUND

Radicular pain has been considered to be a relative contraindication to vertebroplasty. It was reported by some authors in the literature that percutaneous vertebroplasty (PV) in these conditions were performed without complications.

OBJECTIVE

We describe a patient with radicular pain related to compression of the dorsal root ganglion by malignant tumor which was relieved after PV.

STUDY DESIGN

Case report.

SETTING

Pain management clinic.

CASE REPORT

 A 52-year-old man with spine metastasis involving the dorsal root ganglion of the left L4 nerve was admitted to the pain clinic with a tingling sensation and pain in both legs for 6 months. He was not able to lie on his back with his left leg extended or stand without weakness. The transforaminal epidural block had only a transient effect. The patient planned to undergo PV. He complained of severe radicular pain in his left leg approximately 5 minutes after the vertebroplasty. A left L4/5 transforaminal epidural block was performed. The next day, the patient's pain was relieved without any complications. He underwent palliative radiation therapy for multiple metastases of the thoracolumbar spine. At 5 months follow-up, he could lie on his back without recurrence of radicular pain.

LIMITATIONS

This report describes a single case report.

CONCLUSION

We suggest that carefully performed PV is an option for terminally ill patients with epidural and dorsal root ganglion involvement who do not respond to conservative treatment or cannot undergo radiation therapy and surgery. PV is minimally invasive compared to open surgery and may merit serious consideration in patients with limited physiologic reserves.

[Novel artificial lamina for prevention of epidural adhesions after posterior cervical laminectomy]

OBJECTIVE

To evaluate the application of artificial lamina of multi-amino-acid copolymer (MAACP)/nano-hydroxyapatite (n-HA) in prevention of epidural adhesion and compression of scar tissue after posterior cervical laminectomy.

METHODS

Fifteen 2-year-old male goats [weighing, (30 +/- 2) kg] were randomly divided into experimental group (n=9) and control group (n=6). In the experimental group, C4 laminectomy was performed, followed by MAACP/n-HA artificial lamina implantations; in the control group, only C4 laminectomy was performed. At 4, 12, and 24 weeks after operation, 2, 2, and 5 goats in the experimental group and 2, 2, and 2 goats in the control group were selected for observation of wound infection, artificial laminar fragmentation and displacement, and its shape; Rydell's degree of adhesion criteria was used to evaluate the adhesion degree between 2 groups. X-ray and CT images were observed; at 24 weeks after operation, CT scan was used to measure the spinal canal area and the sagittal diameter of C3, C4, and C5 vertebrea, 2 normal goats served as normal group; and MRI was used to assess adhesion and compression of scar tissue on the dura and the nerve root. Then goats were sacrificed and histological observation was carried out.

RESULTS

After operation, the wound healed well; no toxicity or elimination reaction was observed. According to Rydell's degree of adhesion criteria, adhesion in the experimental group was significantly slighter than that in the control group (Z= -2.52, P=0.00). X-ray and CT scan showed that no dislocation of artificial lamina occurred, new cervical bone formed in the defect, and bony spinal canal was rebuilt in the experimental group. Defects of C4 vertebral plate and spinous process were observed in the control group. At 24 weeks, the spinal canal area and sagittal diameter of C4 in the experimental group and normal group were significantly larger than those in the control group (P < 0.05), but no significant difference was found between experimental group and normal group (P > 0.05). MRI showed cerebrospinal fluid signal was unobstructed and no soft tissue projected into the spinal canal in the experimental group; scar tissue projected into the spinal canal and the dura were compressed by scar tissue in the control group. HE staining and Masson trichrome staining showed that artificial lamina had no obvious degradation with high integrity, some new bone formed at interface between the artificial material and bone in the experimental group; fibrous tissue grew into defect in the control group.

CONCLUSION

The MAACP/n-HA artificial lamina could maintaine good biomechanical properties for a long time in vivo and could effectively prevent the epidural scar from growing in the lamina defect area.

[Diagnosis and management for the non-traumatic epidural sequestered cervical disc extrusion]

OBJECTIVE

To explore the clinical characteristics and management of non-traumatic epidural sequestered cervical disc extrusion.

METHODS

From January 2002 to July 2011, the clinical data of 10 patients with non-traumatic epidural sequestered cervical disc extrusion were treated by anterior cervical mostly vertebraectomy and nucleus pulposus removal after decompression and internal fixation through longitudinal ligament resection. Of them,there were 6 males and 4 females with an average age of 48.2 years old (ranged from 42 to 65), the course of disease ranged from 1 month to 4 years (mean, 15 months). All patients manifested numbness and weakness of four limbs, unstable walking and sphincter of oddi dysfunction. Preoperative MRI showed segmental cervical spinal cord compression. JOA scoring criteria was applied to evaluate preoperative and follow-up neurologic function.

RESULTS

Ten patients were followed up, and the duration ranged from 15 to 32 months, with an average of 21 months. No complications related to opreation occurred. Preoperative MRI showed nucelus puplposus sequestered longitudinal ligament were on equal signal on T1-weighted and corresponding pathological,while it showed equal and high signal on T2-weighted. JOA score were increased from 7.20 +/- 1.55 preoperative to 13.60 +/- 1.90 postoperative (t = -11.8, P < 0.001), and excellent in 3 cases, good in 6 cases and moderate in 1 case.

CONCLUSION

Anterior cervical mostly vertebraectomy and nucleus pulposus removal after decompression and internal fixation through longitudinal ligament resection after early diagnosis is the key to success of treating non-traumatic epidural sequestered cervical disc extrusion.

Steroid-induced paraparesis: spinal epidural lipomatosis complicated by a wedge deformity of the middle thoracic vertebrae

Steroid therapy is commonly prescribed, although a variety of complications have been reported. Among such complications, spinal epidural lipomatosis is rare and difficult to diagnose before paraparesis occurs. The purpose of this report is to present a rare but catastrophic complication of steroid therapy. A 64-year-old woman undergoing long-term steroid therapy suffered from an osteoporotic vertebral compression fracture and was unable to walk due to paraparesis. Magnetic resonance imaging (MRI) demonstrated a D7 compression fracture and stored epidural adipose tissue between D5 and D8. After surgery, the patient was able to walk with double canes. This case indicates that long-term steroid use has the potential to induce paraparesis.

A biomechanical evaluation of the epidural neurolysis procedure

BACKGROUND

The epidural lysis of adhesions (ELOA) procedure supposedly has a biomechanical component in addition to the targeted injection of medications into the epidural space. It is assumed that the catheters used for the ELOA procedure can release epidural scars and adhesions.

OBJECTIVES

To evaluate the possible biomechanical effects of the typically used catheters and to put these effects into clinical perspective.

STUDY DESIGN

Experimental study.

SETTING

The biomechanical laboratory of an academic orthopedic surgery department.

METHODS

Experimental setups were devised that allow for the measurement of the 3 main forces that can be exerted by manipulating a catheter in the epidural space or by injecting fluids through such a catheter: axial forces, torsional forces, and hydraulic effects.

RESULTS

The maximum axial forces measured under extremely tight catheter guidance were 7 newton (N), whereas the maximum forces under conditions that more likely reflect a real treatment situation were between 1 and 2 N. The maximum torsional forces measured were 0.3 N under extremely tight catheter guidance and 0.01 N under more realistic conditions. The maximum flow that could be achieved through the typical catheter using normal saline and the maximum possible thumb pressure onto a 5 mL or a 10 mL Luer-Lock syringe was 0.48 mL/ s. Given these results and other data available to us, it appears impossible that the ELOA procedure with typically used catheters has any relevant mechanical effect.

LIMITATIONS

Like with any experimental study, the realities of an in vivo situation can only be modeled to a limited degree. The main limitation of our study is that we cannot calculate, measure, or simulate neither the flow resistance between an epidural adhesion pocket and the open, local epidural space nor the flow resistance between the open, local epidural space and the larger epidural space as well as the retroperitoneal space.

CONCLUSIONS

According to our findings and arguments, the ELOA procedure is predominantly a method for the highly targeted application of epidural medications and possibly also has a lavage effect. A mechanical lysis of scars or adhesions appears unlikely.

Preparation and characterization of a new gellan gum and sulphated hyaluronic acid hydrogel designed for epidural scar prevention

Postsurgical adhesions are a common problem in clinical practice, causing nerve compression, pain and discomfort. A new hydrogel based on gellan gum and sulphated hyaluronic acid was synthesized, with the aim to create an effective barrier for epidural scar formation. Physico-chemical properties of the gel were analyzed, and preliminary biocompatibility data (i.e. cytotoxicity) have been collected in view of its potential clinical use. The characterization of the new material demonstrated that the hydrogel, due to its high-viscosity, could effectively act as a barrier with a long in situ residence time. In addition, the hydrogel can be easily extruded from a syringe and its structure exhibits excellent stabilizing properties. Furthermore, biological assays showed that this gel is suitable for further preclinical development.

Periduroscopy: general review of clinical features and development of operative models

BACKGROUND

Myeloscopy is a useful approach for both diagnosis and treatment of back pain. However clinicians have underestimated its potential. From the nineties myeloscopy has been used only as a diagnostic tool, without any improvement of the technique. Racz's method is nowadays still used for the lysis of adherence by applying medical solutions without a direct vision inside the spinal channel. In 1998 we showed the limitations of Racz's approach, and in 1999 we developed a new technique, introducing a Fogarty balloon to remove the occlusions of the spinal canal and the resaflex for the lysis of adherence at low temperature (Raffaeli-Righetti technique). In this paper we report a general review of our experience with periduroscopy for the treatment of failed back surgery syndrome (FBSS) and spinal stenosis.

METHOD

A Fogarty balloon was used to remove fat and/or mild fibrosis occluding the spinal canal, reducing by 50% the volume of the saline solution used in periduroscopy. The Resaflex was subsequently used to lyse adherence and to allow reaching the site of pain origin, using a low temperature (> 50°C).

FINDINGS

the fibrosis morphologies of epidural space (ES) were grouped on the basis of common macroscopic and organizational characteristics, which were revealed during myeloscopy. A year after myeloscopy, 59% of FBSS patients, and 67% of patients with stenosis reported a general improvement of their painful pathology, with a pain reduction above 50 in 56% of patients. Forty-eight percent of patients used minor analgesics and 67% of patients went back to work. Only few complications were observed (4%).

CONCLUSIONS

myeloscopy technique enlightens pain-triggering mechanisms otherwise unrevealed; it has specific therapeutic value, whereas on the diagnostic side it has not revealed relevant pathologies. Its effectiveness in FBSS patients is high, with the advantage of its relatively easy implementation, limited invasiveness and repeatability.

Tumoral calcinosis and epidural lipomatosis of the lumbar spine

Lumbar spinal tumoral calcinosis and spinal epidural lipomatosis are rare conditions. We present a 70-year-old female patient with serology negative spondyloarthropathy who developed paresis due to tumoral calcinosis in the left facet joint between L5 and S1 levels and spinal epidural lipomatosis at L5 and S1 levels. Surgery was performed to excise the lesions en bloc. Neural decompression was provided. Neurological symptoms improved after surgery. Here, we report the first serology negative spondyloarthropathy case that had concomitant development of tumoral calcinosis and spinal epidural lipomatosis.

[Resection of anterior skull base cranio-nasal communication tumors via the inner plate of frontal sinus-epidural approach]

OBJECTIVE

To explore the application of inner plate of frontal sinus-epidural approach in the treatment of anterior skull base cranio-nasal communication tumors.

METHOD

A study of 6 cranio-nasal communication tumor patients was undertaken. They were treated with lateral rhinotomy-inner plate of frontal sinus-epidural approach to remove tumor.

RESULT

The tumors in all the 6 patients were completely resected. The follow-up study during the following 2 years revealed that 5 patients had good facial appearances and showed no tumor recurrence, no cerebrospinal rhinorrhea, no meningoencephalocele, no frontal collapse, and other complications.

CONCLUSION

The surgical approach in the treatment of Cranio-nasal communication tumors needs to be chosen according to the tumor size, location and nature. Lateral rhinotomy-inner plate of frontal sinus-epidural approach can be carried out independently by the head and neck surgeons. It is a valuable surgical treatment with minimal invasion, short surgery time, little damage to brain, and easy pyrosis of skull base.

A report of paraparesis following spinal cord stimulator trial, implantation and revision

BACKGROUND

Spinal cord injury has been reported as a rare complication of spinal cord stimulation (SCS). A review of the literature shows a very low incidence of neurological injury after spinal cord stimulation trial, implantation and revision. The most common reported complication is equipment failure without neurologic injury. The incidence of spinal cord injury after SCS trial, implantation and revision is unknown. There have been limited reports of neurologic injury secondary to dural puncture, infection, cord contusion, actual needle penetration of the spinal cord and epidural hematoma.

STUDY DESIGN

A report of 4 cases.

OBJECTIVE

To report 4 occurrences of neurological complication after spinal cord stimulator implantation.

METHODS

Four patients are presented who were admitted to an acute spinal cord rehabilitation hospital over a 4-month period. All 4 patients presented with paraparesis after spinal cord stimulator trial or implantation. One of the injuries is secondary to cord contusion, while the other 3 are secondary to cord compressions. Two of these compressions are due to epidural hematomas and one secondary to implantation in the setting of broad based thoracic disc herniations. The clinical cases are presented as well as a review of the literature.

RESULTS

All 4 patients had the electrodes and neurostimulators successfully removed prior to their acute rehabilitation admissions. At discharge from acute inpatient rehabilitation, one patient continued to experience complete paraplegia, 2 patients had incomplete paraparesis and one had fully recovered all of his neurologic function.

CONCLUSION

SCS is considered a safe procedure. Further investigation into the true incidence of neurologic injury after SCS is warranted.

[Echinococcosis of the rib with epidural extension]

Osseous hydatidosis, especially when located in the rib, is a very rare disease. Less than 50 cases of costal echinococcosis have been reported in the literature to date. The authors report a case of echinococcosis of the rib with epidural extension in a 76-year-old patient presenting paraparesis. In addition, the patient presented a large posterior and thoracic soft tissue mass measuring about 30 centimetres in diameter. A chest x-ray, a CT thoracic scan and an MRI of the dorsal spine were performed. The imaging suggested echinococcosis of the rib with epidural extension. The cyst was completely resected. Histopathology of the resected specimen confirmed the diagnosis of echinococcosis. The patient died due to postoperative complications. Accurate presurgical diagnosis allows for appropriate management and helps eradicate the disease. This also prevents the dissemination of parasites and further complications.

Systematic review of percutaneous adhesiolysis and management of chronic low back pain in post lumbar surgery syndrome

BACKGROUND

Post lumbar surgery syndrome or failed back surgery syndrome with persistent pain continues to increase over the years. The speculated causes of post lumbar laminectomy syndrome include acquired stenosis, epidural fibrosis, arachnoiditis, radiculopathy, and recurrent disc herniation. Epidural fibrosis may account for as much as 20% to 36% of all cases of failed back surgery syndrome. Percutaneous epidural adhesiolysis has been employed in interventional pain management in the treatment of chronic, refractory low back and lower extremity pain after back surgery.

STUDY DESIGN

A systematic review of randomized trials and observational studies.

OBJECTIVE

To evaluate the effectiveness of percutaneous adhesiolysis in managing chronic low back and lower extremity pain due to post lumbar surgery syndrome.

METHODS

A comprehensive literature search was conducted utilizing electronic databases, as well as systematic reviews and cross references from 1966 through December 2008. The quality of individual articles used in this analysis was assessed by modified Cochrane review criteria for randomized trials and the Agency for Healthcare Research and Quality (AHRQ) criteria for assessment of observational studies. Clinical relevance was evaluated using 5 questions according to the criteria recommended by the Cochrane Review Back Group. Analysis was conducted using 5 levels of evidence, ranging from Level I to III, with 3 subcategories in Level II.

OUTCOME PARAMETERS

The primary outcome measure was pain relief (short-term relief of at least 6 months and long-term relief of more than 6 months). Secondary outcome measures were improvement in functional status, psychological status, return to work, and change in opioid intake.

RESULTS

Of the 13 studies considered for inclusion, 3 randomized trials and 4 observational studies met the inclusion criteria for methodologic quality assessment and evidence synthesis based on methodologic quality scores of 50 or more. Evidence of percutaneous adhesiolysis in the management of chronic low back pain in post-lumbar surgery syndrome is Level I to Level II-1, with evidence derived from 3 randomized trials.

LIMITATIONS

There is a paucity of efficacy and pragmatic trials. No trials have been published after 2006.

CONCLUSION

The indicated level of evidence for percutaneous adhesiolysis is Level I or II-1 based on the US Preventative Services Task Force (USPSTF) criteria.

Extended lateral parascapular approach for resection of a giant multi-compartment thoracic schwannoma

BACKGROUND

Resection of giant thoracic schwannomas is challenging and usually requires a staged approach. The resection of the intraspinal component, usually via laminectomy, is done in one sitting and the intrathoracic component, via thoracotomy, follows at another. We describe the complete resection of a massive multi-compartmental thoracic schwannoma by an extended lateral parascapular approach.

METHOD AND FINDINGS

The tumor, which presented with local pain and scapular displacement, had intrathoracic paraspinal (10 x 5 x 4 cm), posterolateral upper thoracic paramuscular (19 x 7 x 4 cm), foraminal, and epidural components. It was removed at a single sitting, via a posterior extended lateral parascapular approach that did not require staged procedures, multiple incisions, or repositioning of the patient. This operation included resection of the thoracic, foraminal, and intraspinal components and posterior stabilization with pedicle screws and rods. There were no postoperative neurological complications.

CONCLUSIONS

The extended lateral parascapular approach allows complete resection of giant multi-compartment schwannomas of the thoracic spine that extend from the canal into the thoracic cavity. It also permits posterior stabilization through the same incision used for tumor removal.

Limited approach to a thoracic spine osteoblastoma

Osteoblastoma (OB) is a rare primary benign bone tumor. It generally occurs in the axial skeleton, where it preferentially involves the neural arch. The peak incidence of this neoplasm is in the first two decades of life. Female/male ratio is 2:1. It is important to differentiate OB from osteoid osteoma, a very similar bone tumor. Neuroradiological imaging are diagnostics in most of the cases. This article describes a 18-year-old female affected from a thoracic osteoblastoma stemming from T9 lamina and extending to T11, with a diameter of about 2.5 cm. The patient complained of dorsal pain with progressive weakness to lower limbs. A dorsal approach was performed with a right partial T9 and T11 right laminectomy with total T10 right laminectomy. The mass was totally removed by a limited approach, with no consequent instability and no reason for any stabilization. OB is rare benign bone neoplasm that generally affect the posterior elements of the spine. Surgery is the treatment of choice in this kind of lesions: total removal is effective with no recurrence. When the lesion is placed in the cervical and thoracic spine the goal is to decompress spinal cord and reach the stability of the spine.

Sectioning of filum terminale externum using a rigid endoscope through the sacral hiatus. Cadaver study

AIM

Tethered cord syndrome (TCS) is a stretch-induced functional disorder of the spinal cord, which is directly related to filum fixation. Classic surgical approaches to the filum involve open surgery and include varying amounts of spinal bone removal. In an effort to reduce the morbidity and mortality of these procedures, the authors explored a less invasive method. They evaluated the ability, safety and feasibility for endoscopic sectioning of the filum terminale externum by performing upward orientated navigation in the extradural sacral spinal canal through the sacral hiatus using a rigid endoscope.

METHODS

Four adult, phenol-formalin embalmed cadavers were used for endoscopic section of the filum terminale externum at the tip of thecal sac. After preparing the anatomical area of sacral hiatus, a rigid endoscope (Storz, of 3.8 mm external diameter with two working channels, of 1 mm each, one for suction-irrigation and one as working) was inserted into the extradural sacral spinal canal and the filum terminale externum was identified and cut easily at the distal end of thecal sac at the level of S2. In all cases, it was possible to manipulate the rigid endoscope and inspect the full length of the extradural sacral spinal canal, especially at the S1-S2 level.

RESULTS

The results indicate that the tested transhiatal approach for upward orientated extradural endoscopy represents a minimally invasive procedure that provides an appropriate and feasible route to the extradural sacral spinal canal.

CONCLUSION

Such approach is an attractive alternative for filum terminale externum sectioning in cases where tethered cord syndrome is not accompanied by any other pathology. Moreover if filum terminale internum sectiong is indicated, it can be performed in second stage.