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PubMed2005

Risk factors for scoliosis in children with neuroblastoma.

PURPOSE: To determine the risk factors for scoliosis in children treated for neuroblastoma. METHODS AND MATERIALS: From 1957 to 1997, 58 children with neuroblastoma were treated at one institution and have survived a minimum of 5 years. There were 35 boys and 23 girls with a median age of 6 months (range, 2 weeks to 15 years) at initial diagnosis. Primary site was located in the adrenal gland in 25 (43.1%), abdominal/nonadrenal in 16 (27.6%), thoracic in 12 (20.7%), cervical in 3 (5.3%), and pelvic region in 2 (3.5%). The International Neuroblastoma Staging System (INSS) stage was Stage 1 in 10 (17.2%), Stage 2A in 7 (12.1%), Stage 2B in 5 (8.6%), Stage 3 in 22 (37.9%), Stage 4 in 4 (6.9%), and Stage 4S in 10 (17.2%). Thirty-three (56.9%) received chemotherapy whereas 5 (8.6%) had a laminectomy as part of the surgical procedure. Twenty-seven (46.6%) received radiotherapy (RT). Beam energy was 1.25 MV in 11 (41%), 250 kV in 10 (37%), 4 MV in 4 (15%), and 6-MV photons in 1 patient. One patient received 300 cGy in 1 fraction total skin RT using 6-MeV electrons. For the remaining patients, fraction size was 100 cGy in 6 (22%), 150-180 cGy in 11 (41%), 200 cGy in 4 (15%), and 250-300 cGy in 3. Three patients had total body irradiation at 333 cGy for 3 fractions. For all children who received RT, median total dose was 2000 cGy (range, 300-3900 cGy). Patients who were treated with RT had plain films of the irradiated area every 1 to 2 years until at least the age of puberty. Median follow-up was 10 years (range, 5-46 years). RESULTS: The overall 5-, 10-, and 15-year scoliosis-free rates were 87.6%, 79.0%, and 76.0% respectively. Twelve (21%) developed scoliosis at a median time of 51 months (range, 8-137 months). The degree of scoliosis was mild (< or =20 degrees ) in 8 (67%). Four had scoliosis ranging from 30 degrees to 66 degrees ; 3 of these patients required surgical intervention, whereas 1 had an underlying Duchenne muscular dystrophy which manifested itself 8 years after diagnosis of neuroblastoma. Median time to scoliosis was 23 months (range, 8-54 months) in children who had a laminectomy. On multivariate analysis, both history of laminectomy (p = 0.0005) and use of RT (p = 0.0284) were found to be risk factors for development of scoliosis. Gender, age at diagnosis, INSS stage, primary site, and use of chemotherapy were not found to be significant. Both RT fraction size and beam energy were also not significant, but increasing total RT dose was found to be significant (p = 0.0039). The 15-year scoliosis-free rates were 20% for children who had a laminectomy and 81.3% for those who did not have a laminectomy. The 15-year scoliosis-free rates for children treated with RT doses 0 cGy, 1-1750 cGy, 1751-2300 cGy, and >2300 cGy were 91.7%, 87.5%, 51.4%, and 44.4% respectively. CONCLUSIONS: Treatment-related factors, namely laminectomy and radiotherapy, were found to increase the risk of scoliosis in patients with neuroblastoma. Children who had a laminectomy were more likely to manifest scoliosis earlier. Increasing RT dose was found to impact adversely on the development of scoliosis.

Adolescent↗
PubMed1997

Wire fixation techniques of the cervical facets.

STUDY DESIGN: The changes in the biomechanical responses of the cervical spine altered by multilevel laminectomy to various facet wiring techniques were evaluated. OBJECTIVE: To determine the effectiveness of various proposed techniques of cervical facet wiring used to offer rigid internal fixation after multilevel laminectomy. METHODS: Eight human cadaveric spine segments from C2-11 underwent combined flexion-compression loading. After testing intact and three-level laminectomy (C4-C6) preparations, two techniques of facet wiring fixation were evaluated in an identical manner. Force, displacement, and kinematics data at every level of the column were obtained. RESULTS: The mean stiffness of the intact column was significantly greater than the mean stiffness for laminectomized specimens. Individual facet wiring to the bone graft and through the spinous process below the laminectomy failed to restore stiffness to the laminectomized preparations, whereas the Luque rectangle method restored the stiffness to that found in the intact column. The increases in segmental and overall sagittal rotations resulting from multilevel laminectomy were not decreased significantly by the individual facet wiring technique, but the Luque rectangle technique demonstrated a reduction of sagittal rotations compared with laminectomy without fixation. CONCLUSIONS: The significant increases in total column flexibility and segmental flexural rotations after multilevel laminectomy were not corrected by techniques that depend on individual facet wires secured to an overlying strut, including wiring to the inferior intact segment. Crosslinking of the facet wire fixation above and below the laminectomized segments, as exemplified by the Luque rectangle technique, restored column stiffness and reduced segmental sagittal rotations.

Biomechanical Phenomena↗
PubMed1998

Postlaminectomy adhesion of the cauda equina. Inhibitory effects of anti-inflammatory drugs on cauda equina adhesion in rats.

STUDY DESIGN: Effects of the systemic administration of anti-inflammatory drugs on cauda equina adhesion after lumbar laminectomy were evaluated in rats. OBJECTIVES: To obtain basic data on preventive measures for lumbar adhesive arachnoiditis. SUMMARY OF BACKGROUND DATA: Laminectomy-induced cauda equina adhesion has been proved by rat experiments and postoperative serial magnetic resonance imaging tests in humans. In rats, laminectomy induces an increase in vascular permeability, resulting in cauda equina adhesion. METHODS: Wistar rats laminectomized from L5 to L6 were divided into three groups: the control group received only vehicle solutions, the indomethacin group received oral indomethacin for 7 days, and the steroid group was administered intraperitoneal methylprednisolone for 3 days. At 24 hours and 3 weeks and 6 weeks after laminectomy, cauda equina adhesion and leakage of a protein tracer from the nutrient vessels were histologically compared in the three groups. RESULTS: Both indomethacin and methylprednisolone significantly suppressed cauda equina adhesion and protein leakage from the nutrient vessels at 24 hours after laminectomy. Rats treated with the anti-inflammatory drugs showed diminution of cauda equina adhesion and the neural degeneration at 3 weeks and 6 weeks after laminectomy. CONCLUSIONS: Anti-inflammatory drug administration before and after laminectomy suppressed cauda equina adhesion as well as facilitating recovery from cauda equina adhesion.

Animals↗
PubMed2005

A traumatic central cord syndrome occurring after adequate decompression for cervical spondylosis: biomechanics of injury: case report.

STUDY DESIGN: Case report with review of the literature. OBJECTIVES: To present the first case of a central cord syndrome occurring after adequate decompression, and review the mechanics of the cervical spinal cord injury and postoperative biomechanical and anatomic changes occurring after cervical decompressive laminectomy. SUMMARY OF BACKGROUND DATA: Cervical spondylosis is a common pathoanatomic occurrence in the elderly population and is thought to be one of the primary causes for a central cord syndrome. Decompressive laminectomy with or without fusion has been a primary treatment for spondylotic disease and is thought to be protective against further injury. To our knowledge, there are no cases of a central cord syndrome occurring after adequate decompression reported in the literature. METHODS: Case study with extensive review of the literature. RESULTS: The patient underwent C3-C7 cervical laminectomy without complications. After surgery, the patient's spasticity and gait difficulties improved. She was discharged to inpatient rehabilitation for further treatment of upper extremity weakness. The patient fell in the rehabilitation center, with a central cord syndrome despite adequate decompression of her spinal canal. The patient was treated conservatively for the central cord and had minimal improvement. CONCLUSIONS: Decompressive laminectomy provides an immediate decompressive effect on the spinal cord as seen by the dorsal migration of the cord, however, the biomechanics of the cervical spine after decompressive laminectomy remain uncertain. This case supports the ongoing research and need for more intensive research on postoperative cervical spine biomechanics, including decompressive laminectomies, decompressive laminectomy and fusion, and laminoplasty.

Accidental Falls↗
PubMed2007

Dorsal surgery for myelopathy and myeloradiculopathy.

OBJECTIVE: To review the dorsal approaches to the cervical spine for myelopathy and myeloradiculopathy. METHODS: The literature was reviewed in reference to dorsal approaches for cervical myelopathy and myeloradiculopathy. RESULTS: There are a variety of surgical approaches in the management of cervical myelopathy and myeloradiculopathy. Deciding which is the best method for any individual requires the surgeon to be aware of the advantages of each technique, as well as the complications and limitations of each approach. CONCLUSION: Laminectomy is the traditional technique used for multilevel cervical stenosis. The complications related to laminectomy, such as late neurological decline, kyphosis, instability, and postoperative radiculopathy, led to laminectomy with fusion. In Japan, dissatisfaction with both laminectomy and laminectomy with fusion led to the development of laminoplasty for dorsal treatment of multilevel cervical stenosis. This article highlights the salient features of preoperative evaluation in this patient population as it pertains to dorsal surgical approaches. Additionally, the techniques of laminectomy, laminectomy with fusion, and laminoplasty are compared, and the results are reviewed.

Humans↗
PubMed1996

[The dorsal approach in degeneratively changed cervical spine].

The posterior approach to the cervical spine was the only method of access to the spinal canal until the anterior approach was developed by Robinson and Smith, and Cloward. With the accumulation of experience in posterior decompression for cervical spondylotic myelopathy (CSM), successful laminectomy was guaranteed only when lordotic alignment of the cervical spine, wide and extensive laminectomy for adequate posterior shift of the spinal cord, and stability of the spine were ensured after surgery. The thick scar formation occasionally seen subsequent to postlaminectomy hematoma could lead to an unfavorable outcome. The insertion of surgical instruments, such as a Kerrison rongeur or a curette, into the spinal canal without being aware of how narrow the canal is, or uneven decompression of the spinal cord during resection of the laminae can impinge on or distort the spinal cord and result in deterioration of neurological function. Several authors have pointed out that postoperative loss of neural function is a hazard of surgical intervention. Owing to the poor results of conventional laminectomy for cervical compression myelopathy related to the problems mentioned above, Kirita developed extensive simultaneous decompression laminectomy to avoid distortion of the spinal cord by the edges of the resected laminae. Hattori devised an expansive Z-shaped laminoplasty in which the posterior wall of the spinal canal was preserved by Z-plasty of the prepared laminae. This was an attempt to prevent the invasion of scar tissue, i.e., the so-called laminectomy membrane, which was believed to be a cause of late neurological regression. He also expected that the laminae reconstructed by Z-plasty would provide support for the spine. The introduction of high-speed air-drills allowed successful development of this procedure. In 1977, Hirabayashi introduced an epoch-making laminoplasty, the expansive open-door laminoplasty. He described the advantages of this procedure as: possibility of decompressing multiple levels of the spinal cord simultaneously, better postoperative support of the neck, allowing earlier mobilization of the patients, prevention of postoperative kyphotic deformity of the cervical spine, and reduced mobility of the cervical spine postoperatively, which helps to prevent late neurological deterioration and progression of OPLL. Subsequent to the Hirabayashi laminoplasty, various modifications and supplementary procedures have been devised for further improvement of the safety and efficacy of decompression, and for improved stability of the spine. Aims, advantages and disadvantages of laminoplasty: The aims of the laminoplasty are to expand the spinal canal, to secure spinal stability and to spare the protective function of the spine. Preservation of mobility of the spine is also a goal of this procedure for multiple level involvement. Decompression can be extended along the nerve root by facetectomy. Preservation of the posterior spinal structures permits reinsertion of the nuchal muscles and the spinal ligaments after they have been totally or partially detached. This prevents kyphosis or listhesis of the cervical spine, which often develops after laminectomy, particularly in subjects below 50 years of age. Reconstructive procedures for reattaching muscles and/or ligaments to the spinous processes are added to the laminoplasty, improving the dynamic or ligamentous stability of the spine.

Cervical Vertebrae↗
PubMed1995

Spinal cord missile injuries during the Lebanese civil war.

BACKGROUND: Spinal cord injuries due to penetrating wounds are not uncommon. The management of these injuries remains controversial especially with regard to the effect of laminectomy on the neurological outcome. METHODS: Between 1980 and 1989, 64 patients injured by bullets and shell fragments to the spinal cord were reviewed. There were 58 males and 6 females: 24 injuries (37.5%) involved the cervical spine, 37 (57.8%) the dorsal spine, and 3 (4.7%) the lumbar spine. One group (group I) consisted of 47 patients (73.4%) who had immediate and complete sensorimotor loss of function. Another group (group II) contained 13 patients (20.3%) who presented with incomplete and non-progressive spinal cord deficit. One patient (1.6%) (group III) had progressive spinal cord deficit. Three patients (4.7%) (group IV) had injuries to the cauda equina. RESULTS: The results were analyzed using a chi-squared test when possible. In group I, 20 patients (42.5%) underwent laminectomy with no recovery, and 27 (57.5%) were treated conservatively, with 1 patient (3.7%) achieving marked improvement (p > 0.05). In group II, 3 patients (23.1%) underwent laminectomy with the 3 (100%) improved, and 10 patients (76.9%) were treated conservatively, with 8 (80%) recovering (p > 0.05). CONCLUSIONS: Our data in groups I and II agree with previously published literature that shows no significant advantage of performing laminectomies following penetrating spinal cord injuries. Moreover, group I patients had a poor prognosis whether laminectomy was done or not, and group II patients had a good prognosis whether laminectomy was done or not.

Adolescent↗
PubMed1999

Bone SPECT of the back after lumbar surgery.

PURPOSE: It may be difficult to evaluate back pain in patients who have undergone spinal surgery, because symptoms may be secondary to all the possible abnormalities in patients who have not had surgery plus postoperative complications, including infection, unstable fusion sites, or transfer of biomechanical stresses to other regions. MATERIALS AND METHODS: Sixty-three patients with back pain and a history of lumbar spinal surgery had bone SPECT examinations. Twenty-eight patients had laminectomies, 10 had laminectomies with fusion, 10 had laminectomies with fusion and metallic stabilization devices (3 of which were removed), 7 had fusion without laminectomy, 7 had discectomies, and 1 had a fusion with metallic stabilization but no laminectomy. Eighty-seven percent of the fusions were posterior. The results of SPECT scanning were correlated with surgery, clinical information, and diagnostic radiologic studies. RESULTS: Patients with fusions tended to be scanned further out from the time of surgery than were patients with laminectomy alone or especially discectomy. Bone SPECT excluded bony abnormalities in the operative site in 7 of 63 patients. One hundred thirty-two lesions were uncovered, with facet abnormalities (n = 51) the most common followed by disc space-centered conditions (n = 29), pseudarthrosis (n = 20), sacroiliac joint (n = 18), vertebral body lesions (n = 9), and miscellaneous sites (n = 5). Sixty percent of the abnormalities located in the facets, disc spaces, and vertebral bodies were located in the operative field, whereas 29% were above and 11% were below it. CONCLUSION: Bone SPECT was useful in evaluating these patients to exclude bony lesions or to identify pseudarthrosis, abnormal facets, disc space-centered lesions, and sacroilitis.

Adult↗
PubMed2001

Spinal sagittal malalignment following surgery for primary intramedullary tumours in children.

BACKGROUND/OBJECTIVE: As prior studies analysed predictive factors for various post-laminectomy spinal deformities in mixed spinal regions, age groups or pathologies, their validity and conclusions were unclear. The objective of this study was to determine predictive factors for worsened cervical or thoracic spinal sagittal alignment following laminectomy or laminotomy for primary intramedullary spinal cord tumours in children. METHODS: In this retrospective study, patients treated between 1980 and 1998 were reviewed. Changes in spinal alignment at the last follow-up compared to the pre-operative state were studied. Factors analysed were age, pre-operative spinal alignment, procedure types (laminectomy or laminoplasty), number of laminae operated, surgery of C2 or T1 laminae, histological grade, presence of post-operative neurological deficit and post-operative radiotherapy. RESULTS: There were 27 patients. The mean age was 5.6 years (range 1.3-14.0 years), and the mean duration of follow-up was 3.7 years (range 0.075-9.9 years). In the cervical-cervicothoracic surgical group (n = 12), alignment worsened post-operatively in 3 patients. The number of laminae operated upon had a statistically significant impact on the development of post-operative kyphosis (p = 0.07). In the thoracic-thoracolumbar surgical group (n = 15), alignment worsened in 9 patients. Procedure types were statistically significantly different, with laminectomy associated with an increased risk of post-operative kyphosis (p = 0.01). All 5 patients who had spinal fusion for worsened post-operative alignment were in the thoracic-thoracolumbar group; no patients in the cervical-cervicothoracic group required spinal fusion (p = 0.047). Other predictive factors did not reach statistical significance (p > 0.05). CONCLUSIONS: Worsened spinal sagittal alignment following laminectomy or laminoplasty and the need for spinal fusion is more common in the thoracic-thoracolumbar region than in the cervical-cervicothoracic region. In the cervical-cervicothoracic region, operation on a greater number of laminae tends to increase the risk of worsened alignment. In the thoracic-thoracolumbar region, laminectomy is associated with worsened alignment, while laminoplasty reduces this risk; also, pre-operative kyphotic deformity tends to increase the risk of worsened alignment post-operatively.

Adolescent↗
PubMed2001

Neuroblastoma with symptomatic spinal cord compression at diagnosis: treatment and results with 76 cases.

PURPOSE: To report on the treatment of patients with newly diagnosed neuroblastoma presenting with spinal cord compression (SCC). PATIENTS AND METHODS: Of 1,462 children with neuroblastoma registered between 1979 and 1998, 76 (5.2%) presented with signs/symptoms of SCC, including motor deficit in 75 patients (mild in 43, moderate in 22, severe [ie, paraplegia] in 10), pain in 47, sphincteric deficit in 30, and sensory loss in 11. Treatment of SCC consisted of radiotherapy in 11 patients, laminectomy in 32, and chemotherapy in 33. Laminectomy was more frequently performed in cases with favorable disease stages and in those with severe motor deficit, whereas chemotherapy was preferred in patients with advanced disease. RESULTS: Thirty-three patients achieved full neurologic recovery, 14 improved, 22 remained stable, and eight worsened, including three who become paraplegic. None of the 10 patients with grade 3 motor deficit, eight of whom were treated by laminectomy, recovered or improved. In the other 66 patients, the neurologic response to treatment was comparable for the three therapeutic modalities. All 11 patients treated by radiotherapy and 26 of 32 patients treated by laminectomy, but only two of 33 treated by chemotherapy, received additional therapy for SCC. Fifty-four of 76 patients are alive at time of the analysis, with follow-up of 4 to 209 months (median, 139 months). Twenty-six (44%) of 54 survivors have late sequelae, mainly scoliosis and sphincteric deficit. CONCLUSION: Radiotherapy, laminectomy, and chemotherapy showed comparable ability to relieve or improve SCC. However, patients treated with chemotherapy usually did not require additional therapy, whereas patients treated either with radiotherapy or laminectomy commonly did. No patient presenting with (or developing) severe motor deficit recovered or improved. Sequelae were documented in 44% of surviving patients.

Adolescent↗
PubMed2003

Cervical laminoplasty: a critical review.

OBJECT: The technique of cervical laminoplasty was developed to decompress the spinal canal in patients with multi-level anterior compression caused by ossification of the posterior longitudinal ligament or cervical spondylosis. There is a paucity of data confirming its superiority to laminectomy with regard to neurological outcome, preserving spinal stability, preventing postlaminectomy kyphosis, and the development of the "postlaminectomy membrane." METHODS: The authors conducted a metaanalysis of the English-language laminoplasty literature, assessing neurological outcome, change in range of motion (ROM), development of spinal deformity, and complications. Seventy-one series were reviewed, comprising more than 2000 patients. All studies were retrospective, uncontrolled, nonrandomized case series. Forty-one series provided postoperative recovery rate data in which the Japanese Orthopaedic Association Scale was used for assessing myelopathy. The mean recovery rate was 55% (range 20-80%). The authors of 23 papers provided data on the percentage of patients improving (mean approximately 80%). There was no difference in neurological outcome based on the different laminoplasty techniques or when laminoplasty was compared with laminectomy. There was postlaminoplasty worsening of cervical alignment in approximately 35% and with development of postoperative kyphosis in approximately 10% of patients who underwent long-term follow-up review. Cervical ROM decreased substantially after laminoplasty (mean decrease 50%, range 17-80%). The authors of studies with long-term follow up found that there was progressive loss of cervical ROM, and final ROM similar to that seen in patients who had undergone laminectomy and fusion. In their review of the laminectomy literature the authors could not confirm the occurrence of postlaminectomy membrane causing clinically significant deterioration of neurological function. Postoperative complications differed substantially among series. In only seven articles did the writers quantify the rates of postoperative axial neck pain, noting an incidence between 6 and 60%. In approximately 8% of patients, C-5 nerve root dysfunction developed based on the 12 articles in which this complication was reported. CONCLUSIONS: The literature has yet to support the purported benefits of laminoplasty. Neurological outcome and change in spinal alignment are similar after laminectomy and laminoplasty. Patients treated with laminoplasty develop progressive limitation of cervical ROM similar to that seen after laminectomy and fusion.

Cervical Vertebrae↗
PubMed1994

[Postlaminectomy kyphosis of the cervical spine complicating spinal cord tumor in the foramen magnum].

Postlaminectomy kyphosis is rarely encountered as a sequela of decompression of the upper cervical spine, especially in adults. We present a case of disabling cervical kyphosis which developed after laminectomy for excision of a foramen magnum tumor and was treated successfully by occipito-vertebral fusion. A sixty-one-year old female was treated by laminectomy of the first through to the third cervical spine for a foramen magnum meningioma. One year later, the laminectomy was extended downward to include the fourth through to the seventh cervical spine because of neurological deterioration. Seven years after the first laminectomy, she was referred to our spinal service because of severe neck pain, numbness and muscle weakness of both upper extremities. Lateral X-ray of her cervical spine presented a severe kyphosis. Roentgenogram two months after the first laminectomy already showed slight deformity and, timewise, it corresponded with the time when the patient experienced neurological deterioration. Subsequent X-rays showed progression of kyphosis. After we confirmed a lessening of the pain and improvement of the neurological symptoms during an axial traction using a halo-vest, posterior occipito-cervico-thoracic fusion was performed using Luque segmental spinal instrumentation and autogenous bone graft. After surgery the pain decreased and neurological symptoms improved. It is important to be aware of the complication of kyphotic deformity after laminectomy and once it has developed, it is recommended to stabilize the progression by early spinal fusion.

Cervical Vertebrae↗
PubMed1990

Studies on the permeability of potassium ions across the dura and arachnoid mater of the rat spinal cord.

A combined impounder-surface K+ electrode was developed to measure change in K+ ion concentration of the cerebrospinal fluid (CSF) across the dura and arachnoid maters. To determine whether K+ permeability of the rat dura and arachnoid maters is due to an intrinsic permeability, a study was conducted using an atraumatic laminectomy model. Dorsal laminectomy was performed at T7-8, T12, and L1. Artificial CSF containing 4.2 mM, 24.2 mM, or 54.2 mM of K+ was administered by anterograde subdural infusion into the subarachnoid space from the proximal laminectomy site (T7-8), with effluent overflow at the distal laminectomy site (L1). K+ concentration on the dorsal aspect of the central laminectomy site (T12) was measured. It was found that changes in K+ concentrations of the infused solution were detected by the epidural surface electrode. This suggests that the intact rat spinal cord dura and arachnoid maters may be permeable to K+ in this laminectomy model. This study supports the use of the combined impounder-K+ electrode for measuring changes in K+ ion concentration of the CSF that can result from spinal cord trauma and ischemia.

Adipose Tissue↗
PubMed1999

Expanded polytetrafluoroethylene membrane for the prevention of peridural fibrosis after spinal surgery: a clinical study.

Peridural fibrosis developing after laminectomy may cause pain that can necessitate reoperation. Many materials have been used as a barrier to invasion of fibrous tissue into the vertebral canal, but the ideal material has not been found. Various studies in animals have achieved favourable results with an expanded polytetrafluoroethylene (ePTFE) membrane. In a prospective, randomized study, we compared postoperative results in 33 patients who had an ePTFE membrane implanted to cover the defect caused by laminectomy during lumbar spine decompression with the results in 33 patients in whom no material was implanted. At operation, an ePTFE membrane was placed after the decompression procedure to cover the laminectomy defect completely. Systematic clinical and MRI follow-up evaluations of patients with and without the membrane were conducted 3, 6, 12, and 24 months postoperatively. The effect of ePTFE membrane implantation over laminectomy sites on postoperative peridural fibrosis, pain and neurological claudication was assessed. The ePTFE-membrane group had a significantly lower rate of epidural fibrosis on MRI (P<0.0001) and of clinical manifestations of radiculalgia (P = 0.002) compared with the no-material group. Epidural fibrosis that occurred in the ePTFE group was generally less extensive than that in the no-material group. There was no significant difference in the rate of postoperative claudication in the two groups. Significantly more seromas occurred in the ePTFE group (P = 0.0002). There were no infections or other complications in either group. The results showed that placement of an ePTFE spinal membrane over the laminectomy defect produced by lumbar spine surgery provided a physical barrier to invasion of fibrous tissue into the vertebral canal, and patients with the membrane had less postoperative radicular pain.

Dura Mater↗
PubMed2001

Inhibition of epidural scar tissue formation after spinal surgery: external irradiation vs. spinal membrane application.

PURPOSE: The scar tissue that forms after lumbar dissection is a severe complication and a cause of lumbar and radicular pain. It was recently shown that radiotherapy could inhibit peridural fibrosis after laminectomy. In this study, the efficiency of external irradiation was compared with spinal membrane application. METHOD AND MATERIALS: Thirty male New Zealand rabbits underwent L5 laminectomy. Ten rabbits each received a single fraction of 900-cGy external irradiation administered by 9-MeV electron beam 24 h after the surgery. Ten other rabbits each had spinal membrane applied during laminectomy. The remaining 10 rabbits constituted the control group. All of the rabbits were killed 30 days after the laminectomy. Axial histologic sections through the laminectomy defect were evaluated. Each specimen was scored for the extent and density of fibrosis and arachnoidal adherence. RESULTS: The extent and density of fibrosis and arachnoidal adherence differed significantly between the control group and the treatment groups (p < 0.05). However, the extent and density of fibrosis and arachnoidal adherence did not differ significantly between the spinal membrane and irradiation groups (p > 0.05). CONCLUSION: This preliminary study showed that high-single-fraction/low-total-dose administered postoperatively can successfully inhibit postsurgical epidural fibrosis as effectively as applied spinal membrane.

Animals↗
PubMed1985

Membrane lipid changes in laminectomized and traumatized cat spinal cord.

Free fatty acid (FFA), diacylglycerol (acyl2Gro), icosanoid, phospholipid, and cholesterol levels were measured in samples of cat spinal cord (L2) that were frozen in situ with vertebrae intact, at various times after laminectomy, and at various times after laminectomy with compression trauma to the spinal cord. Tissue samples either were grossly dissected into gray and white portions prior to FFA and acyl2Gro analysis or were used whole for the other lipid types. Gray matter total FFA and acyl2Gro values were abnormally high in samples frozen with vertebrae intact and in those frozen 10 min after laminectomy. This indicates that the surgical procedures resulted in some perturbation of spinal cord lipid metabolism. If the experimental animals were allowed to recover for 90 min after laminectomy, the gray matter FFA and acyl2Gro levels were greatly reduced. Compression of the spinal cord with a 170-g weight for 1, 3, or 5 min (following 90 min of recovery after laminectomy) caused significant elevations of total FFA, acyl2Gro, icosanoids, and phosphatidic acid and significant decreases in ethanolamine plasmalogens and cholesterol. Among the total FFA, arachidonic acid was found to have the largest relative increase. Comparisons of gray and white matter demonstrate that, in general, changes in white matter FFA and acyl2Gro were similar to those seen in gray matter. However, the increases in white matter levels of FFA and acyl2Gro were delayed, occurring after the elevations in gray matter. For some FFA (e.g., arachidonate), the rise in white matter occurred as gray matter levels were decreasing. This suggests that the initial alteration in spinal cord lipid metabolism after trauma was in gray matter but, with time, spread radially into white matter.

Animals↗
PubMed1998

High rates of discitis following surgery for prolapsed intervertebral discs at a hospital in Pakistan.

OBJECTIVES: To confirm the presence of an outbreak of postoperative infections following laminectomy and to determine the infection rate after interventions were instituted. DESIGN: Retrospective cohort study. Medical records were reviewed, personnel interviewed, and premises examined. SETTING: Surgical unit of hospital A in Pakistan. SUBJECTS: Patients who had surgical laminectomy between January 1993 and July 1994. INTERVENTION: Instructive program for nursing and medical staff in December 1993. RESULTS: From January to December 1993, 6 (15%) of 41 laminectomy patients developed postoperative discitis. The risk of discitis varied significantly by surgeon (P = .016); patients who had one particular surgeon, surgeon A, were nine times more likely to develop postoperative infections than patients who did not have surgeon A. Patients were not consistently cleaned or shaved before coming to the operating room, and personnel moved back and forth between the operation theater and other parts of the hospital without changing their gowns or slippers. After the instructional intervention, between January and July 1994, 2 (6%) of 31 laminectomy patients developed postoperative discitis, a rate not significantly lower than in the preceding 12 months (P = .45). Overall, from January 1993 through July 1994, female patients were more likely to develop discitis than males (31% vs 7%; relative risk, 4.4; 95% confidence interval, 1.3-15.6; P < .032). CONCLUSION: Endemic conditions require that laminectomy at hospital A be limited to those situations where the benefits of the surgery exceed the considerable risk of postoperative discitis.

Cohort Studies↗
PubMed1989

Spinal cord sodium, potassium, calcium, and water concentration changes in rats after graded contusion injury.

Spinal cord Na, K, Ca, and H2O changes were measured 6 h after graded contusion injuries in 40 Sprague-Dawley rats. A 10 g weight was dropped 1.25 cm (n = 6), 2.5 cm (n = 7), 5.0 cm (n = 6), or 7.5 cm (n = 7) onto the thoracic spinal cord of 26 rats. An additional 10 rats served as laminectomy controls and 4 rats were unoperated controls. At 6 h after surgery or injury, the spinal cords were rapidly cut into 4 mm segments, weighed to obtain tissue wet weights (W), dried for 14-16 h at 97 degrees C in a vacuum oven (30 mmHg), and reweighed for tissue dry weights (D). Water concentrations ([H2O]d) were estimated from (W-D)/D in units of ml/g D. Ionic concentrations ([Na]d, [K]d, and [Ca]d) of the tissue samples were measured by atomic absorption spectroscopy with units of mumol/g D. Ionic shifts (delta [Na]d, delta [K]d, delta [Ca]d) were calculated by subtracting laminectomy control values from those measured in injured cords. Laminectomy alone significantly increased [Na]d and [H2O]d compared to unoperated controls. Mean +/- standard deviations of [H2O]d, [Na]d, [K]d, and [Ca]d were, respectively, 1.95 +/- 0.07, 182.6 +/- 5.9, 277.2 +/- 11.8, and 12.1 +/- 1.4 in unoperated controls; 2.12 +/- 0.08, 238.6 +/- 9.2, 277.8 +/- 9.2, and 11.7 +/- 1.1 in laminectomy controls. At the impact site, [K]d fell by 14-37% and [H2O]d rose by 14-24%, [Na]d by 13-64%, and [Ca]d by 65-137% of laminectomy control values. delta [Na]d, delta [K]d, and delta [Ca]d correlated linearly with impact velocities; [Ca]d increased by 1.0% per cm/sec (r = 0.995, p less than 0.005), [Na]d increased 0.67% per cm/sec (r = 0.950, p less than 0.01), and [K]d decreased 0.34% per cm/sec (r = 0.964, p less than 0.01). Neither delta [H2O] nor delta [Na]d + delta [K]d consistently predicted impact velocity. [Na]d + [K]d correlated with [H2O]d with a slope of 177.4 mumol/ml (r = 0.697, p less than 0.005). Since Na and K constitute greater than 95% of tissue inorganic ions, the slope approximates net ionic shift per ml of water entry or the ionic osmolarity of edema fluid. These results indicate that increasing contusions produce graded ionic shifts and that edema does not predict contusion severity. These data support our hypothesis that net ionic shifts cause edema in injured spinal cords.

Animals↗