Effets des polyphénols du thé vert et de la radiothérapie sur la progression et la résistance tumorale dans un modèle in vivo de glioblastome

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal

Posterior Dynamic Stabilization as a Salvage Procedure for Lumbar Facet Degeneration Following Total Disc Arthroplasty

Following an L5–S1 SB Charité disc III implantation, a 37-year-old female patient developed intractable radicular pain in the left L5 distribution. The patient underwent a minimally invasive foraminotomy, and her symptoms improved significantly. However, following recurrence of radicular pain, she showed signs of an L5–S1 facet degeneration and recurrent nerve root compression from hypertrophied synovium. A partial facetectomy was then performed to completely decompress the L5 root with supplemental posterior dynamic stabilization using a pedicle-based flexible titanium rod system. To date, the patient remains free of symptoms. Although posterolateral fusion would have been a viable option, the application of a posterior dynamic system permitted segmental motion preservation

Use of hinged rods for controlled osteoclastic correction of a fixed cervical kyphotic deformity in ankylosing spondylitis

Cervical kyphosis in patients with ankylosing spondylitis (AS) can be severely disabling. Surgical treatment of this disorder is technically demanding, however, with a considerable risk of neurological and vascular injuries. The extension osteotomy is a well-described posterior treatment for this condition, but this approach presents the risk of acute subluxation and spinal column translation during the reduction. In this paper, the authors report the novel use of a hinged posterior cervical rod for controlled correction of cervical kyphosis. After sustaining a traumatic spinal fracture, a 57-year-old man with AS developed a delayed cervical flexion deformity. The patient was neurologically intact, but suffered from disabling impairment in horizontal gaze and activities of daily living, and from neck pain. The patient subsequently underwent surgical correction via a posterior cervical extension osteotomy at C7-T1 with manual extension of the neck for osteoclastic reduction of the cervical kyphosis. Controlled correction was performed by using a hinged rod affixed to posterior cervical and thoracic screws, allowing for free sagittal correction while restricting translational forces. Once the desired angle of correction was achieved, the hinge connector was locked, transforming the rod into a rigid device for permanent internal fixation. The use of hinged rods in cervical kyphosis correction provides a controlled method for reduction at the osteotomy site, decreasing the risk of neurological injury

Delayed posttraumatic thoracolumbar spinal deformities: Diagnosis and management

APPROXIMATELY 50,000 TRAUMATIC injuries resulting in fractures of the bony spinal column occur annually in the United States. Although some of these lesions are clearly unstable and mandate urgent surgical treatment for stabilization, less severe injuries may be managed initially with bracing and serial imaging to evaluate bony healing and alignment. A proportion of these injuries will require delayed surgical intervention to correct a posttraumatic deformity. In addition, inadequate or ineffective acute spinal stabilization can also result in the progression of delayed spinal deformities. The management of these lesions is frequently complicated by scarring in the body cavities from the inciting trauma or any subsequent surgical interventions, epidural scar formation and spinal cord tethering, solid fusion into the deformed state, medical comorbidities associated with paralysis, and compromised spinal cord function. With these factors in mind, surgical management of these frequently kyphotic deformities can be performed via a posterior approach with osteotomies or a combined anterior approach and posterior procedures

Multilevel anterior cervical fusion using a collagen-hydroxyapatite matrix with iliac crest bone marrow aspirate: An 18-month follow-up study

OBJECTIVE: The pseudarthrosis rate after multisegment anterior cervical fusion is directly related to the number of levels surgically fused. The advent of osteobiological adjuvants offers an opportunity to reduce both the likelihood of failed arthrodesis and the need for posterior instrumentation. Collagen-hydroxyapatite matrix is osteoconductive and has been used with autogenous bone marrow aspirate (BMA) to promote fusion. We report our results of using collagen-hydroxyapatite matrix with BMA for multilevel anterior cervical discectomy and fusion and anterior cervical corpectomy and fusion (ACCF). METHODS: Sixty-six consecutively treated patients underwent a multilevel anterior cervical discectomy and fusion and/orACCF during a period of 16 months. In all cases, a Smith-Robinson decompression was performed followed by allograft fibula strut grafting filled with collagen-hydroxyapatite matrix and BMA, and anterior semiconstrained cervical plating. A vacuum chamber was used to draw the BMA slowly through the collagen-hydroxyapatite sponges. No patient underwent simultaneous posterior instrumentation. Clinical outcome was determined by an independent observer who evaluated patients on the basis of symptom and neurological examination results. Radiographic fusion was determined by dynamic x-rays and computed tomogmphic scanning during an 1 8-month follow-up period. RESULTS: With the inclusion of discectomies performed in ACCF procedures, patients were fused between two and five disc levels (mean, 3.1 levels). Seventeen patients underwent one to four-level corpectomies (mean, two levels). Clinical improvement was observed in 49 patients. Conditions in nine patients remained unchanged, and two patients had radicular palsies. In all, 60 patients were followed and analyzed for radiographic fusion. All but two patients demonstrated successful radiographic fusion. CONCLUSION: Collagen-hydroxyapatite matrix with BMA can be a safe, effective adjuvant for promoting fusion in multilevel anterior cervical discectomy and fusion and ACCF. Although randomized, controlled studies are necessary to determine whether or not the fusion rates are superior to those obtained from using allograft alone, these I results compare favorably to historical data in. the literature

Dynamic intraspinous spacer technology for posterior stabilization: case-control study on the safety, sagittal angulation, and pain outcome at 1-year follow-up evaluation

Object To assess the safety and efficacy of the DIAM implant, the authors compared the mean 12-month outcomes in patients who underwent lumbar surgery with DIAM placement and in those who underwent lumbar surgery only. Methods Of 62 patients who underwent simple lumbar surgery (laminectomy and/or microdiscectomy) in a 24-month period, 31 underwent concomitant surgical placement of a DIAM interspinous process spacer (33 devices total). Radiographic imaging, pain scores, and clinical assessments were obtained postoperatively to a mean of 12 months (range 8–25 months). Patients who did not undergo implantation of an interspinous process spacer (Group C) were compared with and stratified against patients who underwent placement of a DIAM implant (Group D). In Group D, no statistically significant differences were noted in anterior or posterior disc height when comparing patients pre- and postoperatively. Compared with Group C, a relative kyphosis of less than 2° was noted on postoperative images obtained in Group D. No statistically significant differences in visual analog scale (VAS) pain scores or MacNab outcomes were noted between Groups C and D at a mean of 12 months of follow up. Complications in Group D included three intraoperative spinous process fractures and one infection. Conclusions After simple lumbar surgery, the placement of a DIAM interspinous process spacer did not alter disc height or sagittal alignment at the mean 12-month follow-up interval. No adverse local or systemic reaction to the DIAM was noted. No difference in VAS or MacNab outcome scores was noted between the groups treated with or without the DIAM implants, particularly when the DIAM was used to alleviate low-back pain

Prospective assessment of axial back pain symptoms before and after bariatric weight reduction surgery

The prevalence of obesity in developed countries has reached alarming levels, doubling in the United States since 1980. Although obese patients with chronic low back pain are frequently advised to lose weight, the association between these medical conditions remains unproven. This study prospectively assessed clinically reported changes in chronic axial low back pain symptoms after weight reduction from bariatric surgery for morbid obesity. Prospective longitudinal study. Fifty-eight consecutive patients with morbid obesity and chronic axial low back pain undergoing bariatric surgery over a period of 6 months. Patients were considered morbidly obese if they were 50% to 100% above their ideal body weight or having a body mass index (BMI) greater than 40. Visual Analog Scale (VAS) for axial low back pain, Short Form-36 (SF-36) Health Survey, and Oswestry Disability Index (ODI) Patients undergoing weight reduction surgery were assessed preoperatively and postoperatively at 12 months with validated clinical measures for axial back pain and disability (VAS, SF-36, and ODI). Bariatric surgery parameters included demographic data, weight, and BMI. Statistical analysis included paired t tests and multiple regression techniques. Of the initial 58 patients, 38 (65%) completed both preoperative (Pre-Op) and postoperative (Post-Op) questionnaires at 12 months. These 38 subjects included 30 women and 8 men, with an age range of 20 to 68 years (mean 48.4±10.1). Overall, these patients showed a decrease in mean weight from 144.52±41.21 kg Pre-Op to 105.59±29.24 Post-Op (p<.0001) and BMI from 52.25±12.61 kg/m 2 Pre-Op to 38.32±9.66 Post-Op (p<.0001). Patients demonstrated a statistically significant mean 44% decrease in axial back pain on the VAS scale (p=.006; 5.2±3.35 Pre-Op, to 2.9±3.1 Post-Op). Analysis of the SF-36 major components revealed that patients experienced significant increases in mean physical health by 58% (p<.0001; 44.5±20.09 to 70.24±26.84) and in median mental health by 6% (p=.03; 70±7.14 to 73.39±11.78). Patients also showed statistically significant 24% decrease in Post-Op ODI score for physical disability (p=.05) from 26.75±16.56 Pre-Op to 20.35±18.71 Post-Op (p=.05). This study suggests that the substantial weight reduction after bariatric surgery may be associated with moderate reductions in preexisting back pain at early-follow-up. This effect did not appear to be the result only of an overall improvement in well-being associated with weight loss. However, larger randomized controlled clinical studies with longer-term follow-up are needed to definitively determine a causal relationship

Down-regulation of caveolin-1 in glioma vasculature: modulation by radiotherapy

International audiencePrimary brain tumors, particularly glioblastomas (GB), remain a challenge for oncology. An element of the malignant brain tumors' aggressive behavior is the fact that GB are among the most densely vascularized tumors. To determine some of the molecular regulations occuring at the brain tumor endothelium level during tumoral progression would be an asset in understanding brain tumor biology. Caveolin-1 is an essential structural constituent of caveolae that has been implicated in mitogenic signaling, oncogenesis, and angiogenesis. In this work we investigated regulation of caveolin-1 expression in brain endothelial cells (ECs) under angiogenic conditions. In vitro, brain EC caveolin-1 is down-regulated by angiogenic factors treament and by hypoxia. Coculture of brain ECs with tumoral cells induced a similar downregulation. In addition, activation of the p42/44 MAP kinase is demonstrated. By using an in vivo brain tumor model, we purified ECs from gliomas as well as from normal brain to investigate possible regulation of caveolin-1 expression in tumoral brain vasculature. We show that caveolin-1 expression is strikingly down-regulated in glioma ECs, whereas an increase of phosphorylated caveolin-1 is observed. Whole-brain radiation treatment, a classical way in which GB is currently being treated, resulted in increased caveolin-1 expression in tumor isolated ECs. The level of tumor cells spreading around newly formed blood vessels was also elevated. The regulation of caveolin-1 expression in tumoral ECs may reflect the tumoral vasculature state and correlates with angiogenesis kinetics