Beril Gok

Surgical treatment of cervical spondylotic myelopathy with anterior compression: a review of 67 cases

OBJECT In patients with cervical spondylotic myelopathy (CSM), ventral disease and loss of cervical lordosis are considered to be relative indications for anterior surgery. However, anterior decompression and fusion operations may be associated with an increased risk of swallowing difficulty and an increased risk of nonunion when extensive decompression is performed. The authors reviewed cases involving patients with CSM treated via an anterior approach, paying special attention to neurological outcome, fusion rates, and complications. METHODS Retrospectively, 67 cases involving consecutive patients with CSM requiring an anterior decompression were reviewed: 46 patients underwent anterior surgery only (1-to3-level anterior cervical discectomy and fusion [ACDF] or 1-level corpectomy), and 21 patients who required > 3-level ACDF or > or = 2-level corpectomy underwent anterior surgery supplemented by a posterior instrumented fusion procedure. RESULTS Postoperative improvement in Nurick grade was seen in 43 (93%) of 46 patients undergoing anterior decompression and fusion alone (p < 0.001) and in 17 (81%) of 21 patients undergoing anterior decompression and fusion with supplemental posterior fusion (p = 0.0015). The overall complication rate for this series was 25.4%. Interestingly, the overall complication rate was similar for both the lone anterior surgery and combined anterior-posterior groups, but the incidence of adjacent-segment disease was greater in the lone anterior surgery group. CONCLUSIONS Significant improvement in Nurick grade can be achieved in patients who undergo anterior surgery for cervical myelopathy for primarily ventral disease or loss of cervical lordosis. In selected high-risk patients who undergo multilevel ventral decompression, supplemental posterior fixation and arthrodesis allows for low rates of construct failure with acceptable added morbidity.

Transthoracic surgical treatment for centrally located thoracic disc herniations presenting with myelopathy: a 5-year institutional experience.

Study Design Retrospective review. Objective Review clinical outcomes for myelopathic patients undergoing transthoracic discectomies for central calcified herniations. Summary of Backround Data Ideal surgical treatment for thoracic disc herniation is controversial due to variations in patient presentation, pathology, and possible surgical approach. Although discectomy may lead to improvements in neurologic function, it can be complicated by approach-related morbidity, especially for ventral calcified disc herniations. Review of clinical outcomes for myelopathic patients undergoing transthoracic discectomies for central calcified herniations was completed, paying special attention to neurologic status and procedure-related complications. Methods Between 2002 and 2007, 27 myelopathic patients were treated with 28 transthoracic surgeries for centrally located symptomatic calcified thoracic disc herniations over the last 5 years at a single institution. Demographic data, details of surgery, preoperative and postoperative Nurick and American Spinal Injury Association scores, length of stay, complications, and follow-up data were collected in all patients. Results A total of 27 patients, 8 male (30%) and 19 female (70%) with an average age of 52.3 years (range: 19 to 72) underwent 28 thoracotomies. All had myelopathy whereas 6/27 also had radicular pain syndromes. Fourteen patients had anterior instrumentation alone, 3 had anterior and posterior instrumentation, and 1 had posterior instrumentation alone. Average Nurick grade was 2.5 preoperatively and 1.4 postoperatively. Of note, American Spinal Injury Association scores improved postoperatively in 12/27 patients (10D to 10E; 2C to 2D), remained unchanged in 13/27 (11E to 11E, 2D to 2D), and worsened in 2/27 (2D to 2C). Average length of stay was 7 days (range: 3 to 15). All patients required chest tube placement with average duration of 4 days (range: 1 to 7). Major complications occurred in 6 cases (21.4%) over an average follow-up of 12 months (range: 1 to 40 mo). Conclusions Thoracotomy for treatment of centrally located thoracic disc herniations is associated with improvement in or stabilization of myelopathic symptoms in the majority of patients with an acceptable rate of complications. Interestingly, most patients with weakness improved in strength (12/16, 75%), no patients with normal strength developed new weakness (10/10, 100%), and only 2 patients had new weakness noted postoperatively (7.4%).

Surgical management of cervical spondylotic myelopathy with laminectomy and instrumented fusion.

Abstract Objective: The indications for treating cervical spondylotic myelopathy (CSM) with laminectomy and instrumented fusion remain ill-defined. Cervical laminectomy without instrumented fusion has been associated with suboptimal outcomes, particularly in the setting of cervical kyphosis. This works purpose is to retrospectively review our experience in patients who underwent laminectomy with instrumented fusion for CSM and to assess the neurological and radiological outcomes of patients treated with this technique. Methods: Fifty-four consecutive patients underwent multilevel laminectomy and instrumented fusion for CSM. The indications were patients with (1) cervical stenosis ≥ 3 spinal segments and (2) absence of a cervical kyphosis or (3) patients older than 65 years with significant medical comorbidities. Nurick myelopathy grades and cervical radiographs were obtained preoperatively and at 3, 6, 12 and 24 months post-operatively. Perioperative complications, radiographic and clinical outcomes were assessed and reported in this paper. Results: Forty-four (81%) of patients showed improvement in Nurick grade after surgery by a mean of 17 months. Ten patients (19%) demonstrated stable but unimproved myelopathy. Increasing pre-operative Nurick grade was associated with an improved post-operative outcome (p<0.02). Increasing duration of pre-operative myelopathy was associated with a decreased likelihood of myelopathy improvement (p<0.001). Discussion: Multilevel cervical laminectomy with instrumented fusion for patients with CSM resulted in an improvement in myelopathy in the majority of cases. Efficacy was similar for patients who may not have tolerated an anterior decompression, such as elderly patients with significant medical comorbidities. Hardware-related complication rates were relatively low.

Surgical resection plus adjuvant radiotherapy is superior to surgery or radiotherapy alone in the prevention of neurological decline in a rat metastatic spinal tumor model.

OBJECTIVEThe optimal management of spinal column metastatic disease is controversial. Furthermore, the literature lacks an accurate animal model to study the efficacy of surgical treatment options for spinal column metastases. We compared the efficacy of surgery, radiotherapy, or surgery plus adjuvant radiotherapy in a rat model of metastatic epidural spinal cord compression. METHODSThirty-two Fischer 344 rats underwent a transabdominal approach for implantation of a CRL-1666 breast adenocarcinoma cell line within the vertebral body of L6. Animals were randomly assigned to receive one of four treatments (n = 8 per group) 7 days after tumor implantation: 1) control: no treatment; 2) external beam radiation therapy (XRT) (total 20 Gy in 400-cGy daily fractions); 3) surgery: L6 vertebral corpectomy, tumor resection, and polymethyl methacrylate reconstruction; and 4) surgery + XRT: corpectomy and tumor resection followed by XRT (total 20 Gy in 400-cGy daily fractions) 72 hours after surgery. Hind-limb function was tested daily after treatment using the Basso-Beattie-Bresnahan (BBB) scale (range, 1–21). RESULTSAll animals (n = 32) demonstrated normal hind-limb function (BBB score, 21) on posttreatment Day 1. The XRT, surgery, and surgery + XRT groups all experienced a delay in onset of paresis versus the control group. Compared to the XRT group, the surgery group demonstrated greater median BBB scores on Days 3 (21 versus 20, P = 0.02) through 9 (12 versus 8, P = 0.002) after treatment. Compared with the surgery group, the surgery + XRT group demonstrated even greater median BBB scores on Days 6 (21 versus 19, P = 0.0008) through 11 (16 versus 8, P = 0.0001) after treatment. Median time to loss of ambulation (BBB ≤ 7) was greatest in the surgery + XRT group (15 d) when compared with the surgery (12 d, P = 0.001), XRT (9 d, P = 0.001), or control groups (7 d, P = 0.0005). CONCLUSIONIn a rat model of metastatic epidural spinal cord compression, decompressive surgery followed by radiotherapy yielded the greatest efficacy in the prevention of neurological decline when compared with surgery or radiotherapy alone. Radiotherapy alone attenuated neurological decline but was the least efficacious treatment in this model. These results support this animal model as an effective platform to investigate novel interventions for metastatic spine tumors.

Immunomodulation of acute experimental spinal cord injury with human immunoglobulin G

Immunomodulation of acute spinal cord injury may inhibit the activity of specific inflammatory cascades and result in recovery of motor function. In this study, evaluation of the protective effect of a well-known anti-inflammatory immunomodulator, immunoglobulin G (IgG), was conducted in rats after a 50 g/cm contusion spinal cord injury. Following injury, 400 mg/kg of IgG was administered to the treatment group. Twenty-four hours later, animals were assessed functionally via an inclined plane and the Basso-Beattie-Bresnahan motor scale and compared to controls. Tissue was reviewed for myeloperoxidase activiy (MPO) and lipid peroxidation (LPO), and electron microscopy was conducted to assess tissue ultrastructure. Significant functional preservation was observed in the IgG treatment group. In addition, biochemical assays revealed decreased MPO activity, and electron microscopic views of tissue showed preserved ultrastructure. IgG treatment following acute contusion injury to the rat spinal cord confers functional and structural neuroprotection.

Adjuvant treatment with locally delivered oncogel delays the onset of paresis after surgical resection of experimental spinal column metastasis

OBJECTIVEThe optimal management of spinal column metastatic disease is controversial. Local chemotherapy delivery systems allow targeted high-dose adjuvant therapy. We evaluated whether injection of OncoGel paclitaxel-releasing biodegradable polymer (Protherics, Inc., West Valley City, UT) into the tumor resection cavity at the time of surgery would improve the efficacy of surgical resection with or without external beam radiotherapy (XRT) in a rat model of spinal column metastases. METHODSFischer-344 rats (Charles River Laboratories, Wilmington, MA) underwent a transabdominal approach for implantation of a CRL-1666 breast adenocarcinoma cell line within the L6 vertebral body. In experiment 1, 7 days after tumor implantation, animals underwent 1 of 2 treatments or no treatment (n = 8 per group): control (no treatment); surgery alone (L6 corpectomy); or surgery + OncoGel (L6 corpectomy with OncoGel implantation into the resection cavity). In experiment 2, 7 days after tumor implantation, animals underwent 1 of 2 treatments or no treatment (n = 8 per group): control (no treatment); surgery + XRT (L6 corpectomy followed by XRT [total 20 Gy]); or surgery + XRT + OncoGel (L6 corpectomy with OncoGel implantation followed by XRT). In experiment 3, 7 days after tumor implantation, animals underwent 1 of 2 treatments or no treatment (n = 8 per group): control (no treatment); XRT alone (total 20 Gy); or XRT + OncoGel. Daily hindlimb function was assessed using the Basso, Beattie, and Bresnahan (BBB) scale (range, 1–21). RESULTSIn experiment 1, both treatment groups had delayed onset of paresis compared with control. Compared with surgery alone, surgery + OncoGel resulted in superior median BBB scores on posttreatment days 9 (21 versus 19, P < 0.001) through 14 (11 versus 8, P < 0.005). In experiment 2, both treatment groups had delayed onset of paresis compared with control. Compared with surgery + XRT, surgery + XRT + OncoGel resulted in superior median BBB scores on posttreatment days 13 (21 versus 19, P < 0.001) through 17 (12 versus 8, P < 0.005). Median time to loss of ambulation (BBB scale score ≤7) was maximized by the addition of OncoGel to surgery plus XRT: control (8.5 days), surgery alone (13.5 days), surgery + OncoGel (16 days), surgery + XRT (17 days), and surgery + XRT + OncoGel (19 days). In experiment 3, both treatment groups had delayed onset of paresis compared with control. Compared with XRT alone, XRT + OncoGel resulted in superior median BBB scores on posttreatment days 6 (21 versus 19, P < 0.001) through 11 (13 versus 8, P < 0.005). However, compared with surgery + XRT + OncoGel, XRT + OncoGel resulted in worse median BBB scores on posttreatment days 8 (20 versus 21, P < 0.01) through 13 (7 versus 19, P < 0.005). CONCLUSIONIn a rat model of spinal metastatic disease, local delivery of OncoGel increased the efficacy of surgery and radiotherapy and delayed the onset of neurological decline. These results suggest that OncoGel may be an effective adjuvant therapy in the operative management of metastatic spinal column tumors and that combining local chemotherapy with surgery and adjuvant radiotherapy may improve outcomes of this disease.

Revision surgery for cervical spondylotic myelopathy: surgical results and outcome.

OBJECTIVEThe role of additional or revision surgery in patients with cervical spondylotic myelopathy (CSM) is challenging. Postoperative pseudoarthrosis, instability, hardware failure, and recurrent cervical stenosis are conditions that require detailed clinical and radiographic assessment to define the pathology and assess the need for surgical decompression and fusion. The purpose of this study is to assess the neurological outcome, radiological outcome, and complications of patients undergoing additional or revision surgery for CSM. METHODSBetween 2002 and 2006, 30 patients with CSM and postoperative pseudoarthrosis, instability, hardware failure, or recurrent stenosis underwent surgical decompression and stabilization. The specific procedure was selected according to each patients medical condition, cervical sagittal alignment, and extent of stenosis. All patients underwent an anterior, posterior, or combined anterior and posterior decompression and instrumented fusion. The charts of these patients were reviewed to assess neurological and radiographic outcomes. RESULTSTwenty-five patients (83%) improved postoperatively as measured by the Nurick Myelopathy Scale over a mean follow-up period of 19 months (range, 2–64 mo). The overall complication rate was 27%, consisting of transient monoradiculopathy (7%), dysphagia (10%), and infection (7%). The incidence of nonunion during the follow-up period was 3%. CONCLUSIONAlthough patients with CSM and postoperative pseudoarthrosis, instability, hardware failure, or junctional stenosis who require revision surgery may risk a substantial likelihood of surgical complications (25% in this series), a significant proportion of patients may experience improved neurological outcomes. In our experience, the cervical sagittal alignment and the extent of stenosis are critical factors to consider when selecting the eventual procedure.

Effect of hyperglycemia on progressive paraparesis in a rat metastatic spinal tumor model : Laboratory investigation

OBJECT Hyperglycemia has been shown to potentiate ischemic injury of the spinal cord by quenching vasodilators and potentiating tissue acidosis and free radical production. Steroid-induced hyperglycemia is a common event in the surgical management of metastatic epidural spinal cord compression (MESCC). The goal in this study was to determine whether experimentally induced hyperglycemia accelerates neurological decline in an established animal model of MESCC. METHODS Sixteen Fischer 344 rats underwent a transabdominal approach for implantation of a CRL-1666 breast adenocarcinoma cell line within the vertebral body of L-6. After 72 hours of recovery from tumor implantation, the animals received intraperitoneal injections every 12 hours of either 2 g/kg dextrose in 5 ml 0.09% saline (hyperglycemia, 8 rats) or 5 ml 0.09% saline alone (normoglycemia, 8 rats). Weights were taken daily, and the hindlimb function was tested daily after tumor implantation by using the Basso-Beattie-Bresnahan (BBB) scale (score range 1-21). Animals were killed at time of paralysis (BBB Score < 7), and the volume of epidural tumor growth within the spinal canal was measured. To determine the degree of hyperglycemia induced by this dextrose regimen, a surrogate group of 10 Fischer 344 rats underwent intraperitoneal injections of 2 g/kg dextrose (5 rats) or 0.09% saline (5 rats) every 12 hours, and serum glucose levels were assessed 1, 3, 6, 8, 10, and 12 hours after injections for 24 hours. RESULTS Dextrose versus saline injections resulted in elevated mean serum glucose at 3 (259 vs 103 microg/dl), 6 (219 vs 102 microg/dl), 8 (169 vs 102 microg/dl), and 10 hours (118 vs 99 microg/dl) after injection, returning to normal levels by 12 hours (96 vs 103 microg/dl) just prior to subsequent injection. All rats had normal hindlimb function for the first 8 days after tumor implantation. Hyperglycemic versus normoglycemic rats demonstrated a worsened median BBB score by postimplantation Day 9 (Score 20 vs 21, p = 0.023) through Day 16 (Score 8 vs 12, p = 0.047). Epidural tumor volume demonstrated a near-linear growth rate across both groups; however, hyperglycemic rats developed paralysis earlier (median 15.5 vs 17.5 days, p = 0.0035), with significantly less epidural tumor volume (2.75 +/- 0.38 cm(3) vs 4 +/- 0.41 cm(3), p < 0.001) at time of paralysis. CONCLUSIONS In a rat model of metastatic epidural spinal cord compression, rats maintained in a hyperglycemic state experienced accelerated time to paralysis. Also, less epidural tumor volume was required to cause paralysis in hyperglycemic rats. These results suggest that hyperglycemic states may contribute to decreased spinal cord tolerance to compression resulting from MESCC. Clinical studies evaluating the effect of aggressive glucose control in patients with MESCC may be warranted.

Imaging Metabolic and Molecular Functions in Brain Tumors with Positron Emission Tomography (PET)

Molecular imaging is the amalgamation of molecular biology and imaging technology in a unique way that enables in vivo observation of molecular biological processes without altering the process or organism being studied. Positron Emission Tomography (PET) is the most advanced form of molecular imaging suitable for broad application in human. Since positron-emitting radionuclides of elements such as C, N, O, and F can replace the stable analogues in drugs and biomolecules of fundamental biochemical principles, it is possible to synthesize PET probes with the same chemical structure as the parent unlabeled molecules without altering their biological activity. Fundamental biochemical principles comprise several potential targets including the receptors on the tumor surface, targeting agents based on increased metabolic demands of the cancer, and potentially enzymes or processes which are related to cell growth and survival. Characteristics of the microenvironment of tumors, including tumor perfusion and hypoxia, can also be targeted as well as elements of the tumor stroma.

Ultrastructural changes in the liver after experimental spinal cord injury in rats: effects of methylprednisolone, immunoglobulin g and albumin.

AIM Spinal Cord Injury (SCI) is routinely treated with standardized methyl prednisolone sodium succinate (MPSS) dose, so it is reassuring to find its effects on liver. We also evaluated the effects of albumin and immunoglobulin G (Ig G) therapies on liver if they are used in case of experimental SCI. MATERIAL AND METHODS The rats were allocated into six groups as control, trauma, vehicle, MPSS, Ig G and albumin consisting 8 rats for each. The rats with SCI were assigned to 30mg/kg MPSS, 5 mg/kg albumin and 400 mg/kg Ig G treatments. Tissue samples from liver were obtained for light and electron microscopy examinations and determination of myeloperoxidase (MPO) activity. RESULTS Trauma increased MPO activity and caused cellular changes of liver tissue. Both albumin and Ig G treatments decreased MPO activity significantly. The light and electron microscopic evaluations showed remarkable preservation of liver ultra-structure with all treatments including MPSS. CONCLUSIONS SCI resulted in neutrophil infiltration and changes in ultrastructure of liver. It was revealed that MPSS has no detrimental effects on liver. Although all treatments preserved liver tissue structure, Although all treatments preserved liver tissue structure, Ig G and albumin treatments also prevented neutrophil infiltration. To provide protection from secondary liver injury after SCI, use of albumin and Ig G treatments may be beneficial.