Biomedical subjects

Meic H Schmidt

Publications and source records attributed to Meic H Schmidt.

At least 19 recordsLinked to original sources

PubMed2006

Malignant transformation of conus medullaris ganglioglioma: case report.

Intramedullary gangliogliomas are indolent tumors of the spine with rare cases of malignant transformation. Conus medullaris gangliogliomas are extremely rare but are usually associated with good clinical outcome after gross total resection. We describe the first reported case of a ganglioglioma of the conus medullaris that progressed to glioblastoma multiforme 1 year after subtotal resection and radiotherapy. The paraplegic patient lacked neurological function below the level of the lesion and thus was treated with cordectomy caudal to the root entry zones of the T10 sensory roots.

Adult↗

PubMed2006

Perineural spread of malignant mesothelioma resulting in an intradural spinal cord mass: case report.

Spinal cord involvement by perineural spread of malignant mesothelioma is rare. We report a case of malignant mesothelioma that spread locally to invade the bony spine with both extradural and intradural perineural spread into the spinal canal that resulted in spinal cord compression. A 61-year-old man with a history of malignant mesothelioma presented with progressive leg weakness and right-sided arm weakness. Magnetic resonance imaging showed an enhancing lesion in the apex of the right lung with extension through the C7-T1 foramina with right hemicord enhancement. The patient underwent a C7-T1 laminectomy and right-sided C7-T1 and T1-T2 foraminotomies for neural decompression and biopsy of the lesion. Intraoperatively, tumor extended epidurally, and intradural perineural tumor spread along the C8 and T1 nerve roots into the spinal cord. Because it adhered to the spinal cord, no dissectible plane could be identified that would allow for safe total removal of the tumor. The epidural portion of the tumor, the adjacent involved bone, and the T1 nerve root were resected. Pathologic examination revealed malignant mesothelioma with bony invasion and perineural spread along the T1 nerve root. After decompression of the spinal cord, the patient had moderate improvement of his hand and leg function. Perineural spread of malignant mesothelioma resulting in spinal cord compression is an unusual clinical presentation. Intimate involvement of the spinal cord may prohibit aggressive tumor resection.

Humans↗

PubMed2006

Cervical spine deformity associated with resection of spinal cord tumors.

Postoperative sagittal-plane cervical spine deformities are a concern when laminectomy is performed for tumor resection in the spinal cord. These deformities appear to occur more commonly after resection of intramedullary spinal cord lesions, compared with laminectomy for stenosis caused by degenerative spinal conditions. Postlaminectomy deformities are most common in pediatric patients with an immature skeletal system, but are also more common in young adults (< 25 years of age) in comparison with older adults. The extent of laminectomy and facetectomy, number of laminae removed, location of laminectomy, preoperative loss of lordosis, and postoperative radiation therapy in the spine have all been reported to influence the risk of postlaminectomy spinal deformities. When these occur, patients should be monitored closely with serial imaging studies, because a significant percentage will have progressive deformities. These can range from focal kyphosis to more complicated swan-neck deformities. General indications for surgical intervention include progressive deformity, axial pain in the area, and neurological symptoms attributable to the deformity. Surgical options include anterior, posterior, and combined anterior-posterior procedures. The authors have reviewed the literature on postlaminectomy kyphosis as it relates to resection of cervical spinal cord tumors, and they summarize some general factors to consider when treating these patients.

Cervical Vertebrae↗

PubMed2005

Thoracoscopic spine surgery for decompression and stabilization of the anterolateral thoracolumbar spine.

The anterior thoracolumbar spine can be exposed via a variety of approaches. Historically, open anterolateral or posterolateral approaches have been used to gain access to the anterior thoracolumbar spinal column. Although the exposure is excellent, open approaches are associated with significant pain and respiratory problems, substantial blood loss, poor cosmesis, and prolonged hospitalization. With the increasing use of the endoscope in surgical procedures and recent advances in video-assisted thoracoscopic surgery, minimally invasive thoracoscopic spine surgery has been developed to decrease the morbidity associated with open thoracotomy. The purpose of this article is to illustrate the surgical technique of a minimally invasive thoracoscopic approach to the anterolateral thoracolumbar spine and to discuss its potential indications and contraindications in patients with diseases involving the anterior thoracic and lumbar regions.

Aged↗

PubMed2005

Frameless stereotactic image-guided C1-C2 transarticular screw fixation for atlantoaxial instability: review of 20 patients.

OBJECTIVE: We retrospectively studied 20 adults who underwent C1-C2 transarticular screw (TAS) fixation utilizing frameless stereotaxy. METHODS: The study group comprised 13 men and 7 women, with a mean age of 63 years (range 12-87 years). All patients demonstrated clinical and radiographic evidence of C1-C2 instability. The cause of the instability was trauma in 11 patients, rheumatoid arthritis in 6 patients, failed prior surgery in 2 patients, and congenital malformation in 1 patient. All patients underwent stabilization with C1-C2 TASs using image-guided frameless stereotaxy. RESULTS: There were no new or worsening neurologic symptoms reported at 18-month follow-up. Motor weakness improved in seven of nine patients, myelopathy in seven of seven, and gait in three of six patients in whom these deficits were present preoperatively. Postoperative complications included one surgical site abscess, one cutaneous pressure ulcer, and one iliac crest donor site infection. Of 36 screws placed, 33 (92%) were well positioned. Normal C1-C2 alignment was achieved in 17 of 20 (85%) patients. In 4 of 20 cases, screw implant, which was thought to be anatomically difficult, if not impossible, on the basis of routine magnetic resonance or computed tomography imaging, was actually accomplished successfully using surgical navigation. CONCLUSIONS: C1-C2 TAS placement is a safe and accurate surgical technique that may improve neurologic function. Use of intraoperative navigation can facilitate achieving difficult surgical trajectories that match the patient's anatomy, thus allowing TAS implant in patients who otherwise would not be candidates for this type of internal fixation.

Adolescent↗

PubMed2005

A meta-analysis of surgery versus conventional radiotherapy for the treatment of metastatic spinal epidural disease.

Radiotherapy has been the primary therapy for managing metastatic spinal disease; however, surgery that decompresses the spinal cord circumferentially, followed by reconstruction and immediate stabilization, has also proven effective. We provide a quantitative comparison between the "new" surgery and radiotherapy, based on articles that report on ambulatory status before and after treatment, age, sex, primary neoplasm pathology, and spinal disease distribution. Ambulation was categorized as "success" or "rescue" (proportion of patients ambulatory after treatment and proportion regaining ambulatory function, respectively). Secondary outcomes were also analyzed. We calculated cumulative success and rescue rates for our ambulatory measurements and quantified heterogeneity using a mixed-effects model. We investigated the source of the heterogeneity in both a univariate and multivariate manner with a meta-regression model. Our analysis included data from 24 surgical articles (999 patients) and 4 radiation articles (543 patients), mostly uncontrolled cohort studies (Class III). Surgical patients were 1.3 times more likely to be ambulatory after treatment and twice as likely to regain ambulatory function. Overall ambulatory success rates for surgery and radiation were 85% and 64%, respectively. Primary pathology was the principal factor determining survival. We present the first known formal meta-analysis using data from nonrandomized clinical studies. Although we attempted to control for imbalances between the surgical and radiation groups, significant heterogeneity undoubtedly still exists. Nonetheless, we believe the differences in the outcomes indicate a true difference resulting from treatment. We conclude that surgery should usually be the primary treatment with radiation given as adjuvant therapy. Neurologic status, overall health, extent of disease (spinal and extraspinal), and primary pathology all impact proper treatment selection.

Aged↗

PubMed2005

Titanium cage-assisted polymethylmethacrylate reconstruction for cervical spinal metastasis: technical note.

OBJECTIVE: Reconstruction and stabilization of the cervical spine after vertebrectomy is an important goal in the surgical management of spinal metastasis. The authors describe their reconstruction technique using a titanium cage-Silastic tube construct injected with polymethylmethacrylate (PMMA) augmented by an anterior cervical plate. The surgical results using this technique are reviewed. METHODS: Six patients ranging from 43 to 70 years of age underwent resection of metastatic tumor in the cervical spine followed by cage-assisted PMMA reconstruction of the anterior spinal column. The following reconstruction technique was performed. A Silastic tube is incised longitudinally and placed circumferentially around a titanium cage with the opening facing anteriorly. The cage-Silastic tube construct is carefully tapped into the corpectomy defect and filled with PMMA. The final construct is then augmented with anterior cervical plate fixation. RESULTS: Two patients required additional posterior stabilization with lateral mass screws and rods. All patients achieved immediate stabilization, restoration of vertebral body height and normal lordosis, and preservation of the ability to walk independently. Five patients experienced significant palliation of biomechanical neck pain. There were no complications of neurological worsening, postoperative hematoma, wound infection, subsidence, graft dislodgement, or construct failure during a follow-up period of 1 to 19 months (mean, 6.8 mo). CONCLUSION: Titanium cage-assisted PMMA reconstruction augmented with an anterior cervical plate is an effective means of reconstruction after tumor resection in patients with cervical spinal metastasis. The Silastic tube holds the PMMA within the cage and protects the spinal cord from potential thermal injury.

Adult↗

PubMed2005

Surgical technique and results of endoscopic anterior spinal canal decompression.

OBJECT: Decompression of the spinal canal in the management of thoracolumbar trauma is controversial, but many authors have advocated decompression in patients with severe canal compromise and neurological deficits. Anterior decompression, corpectomy, and fusion have been shown to be more reliable for spinal canal reconstruction than posterior procedures; however, traditional anterior-access procedures, thoracotomy, and thoracoabdominal approaches are associated with significant complications. Endoscopy-guided spinal access avoids causing these morbidities, but it has not been shown to yield equivalent results in spinal canal clearance. This study was conducted to demonstrate the effectiveness of endoscopic spinal canal decompression and reconstruction quantitatively by using pre- and postoperative computerized tomography (CT) scanning. METHODS: Thirty patients with thoracolumbar canal compromise underwent endoscopic anterior spinal canal decompression, interbody reconstruction, and stabilization for fractures (27 cases), and tumor, infection, and severe degenerative disc disease (one case each). The mean follow-up period was 42 months (range 24 months-6 years). Neurological examinations, Frankel grades, radiological studies, and intraoperative findings were prospectively collected. Spinal canal clearance quantified on pre- and postoperative CT scans improved from 55 to 110%. A total of 25% of patients with complete paraplegia and 65% of those with incomplete neurological deficit improved neurologically. The complication rate was 16.7% and included one reintubation, two pleural effusions, one intercostal neuralgia, and one persistent lesion of the sympathetic chain. CONCLUSIONS: The authors describe the endoscopic technique of anterior spinal canal decompression in the thoracolumbar spine. The morbidities associated with an open procedure were avoided, and excellent spinal canal clearance was accomplished as was associated neurological improvement.

Adult↗

PubMed2005

Atlantoaxial transarticular screw fixation: a review of surgical indications, fusion rate, complications, and lessons learned in 191 adult patients.

OBJECT: In this, the first of two articles regarding C1-2 transarticular screw fixation, the authors assessed the rate of fusion, surgery-related complications, and lessons learned after C1-2 transarticular screw fixation in an adult patient series. METHODS: The authors retrospectively reviewed 191 consecutive patients (107 women and 84 men; mean age 49.7 years, range 17-90 years) in whom at least one C1-2 transarticular screw was placed. Overall 353 transarticular screws were placed for trauma (85 patients), rheumatoid arthritis (63 patients), congenital anomaly (26 patients), os odontoideum (four patients), neoplasm (eight patients), and chronic cervical instability (five patients). Among these, 67 transarticular screws were placed in 36 patients as part of an occipitocervical construct. Seventeen patients had undergone 24 posterior C1-2 fusion attempts prior to referral. The mean follow-up period was 15.2 months (range 0.1-106.3 months). Fusion was achieved in 98% of cases followed to commencement of fusion or for at least 24 months. The mean duration until fusion was 9.5 months (range 3-48 months). Complications occurred in 32 patients. Most were minor; however, five patients suffered vertebral artery (VA) injury. One bilateral VA injury resulted in patient death. The others did not result in any permanent neurological sequelae. CONCLUSIONS: Based on this series, the authors have learned important lessons that can improve outcomes and safety. These include techniques to improve screw-related patient positioning, development of optimal instrumentation, improved screw materials and design, and defining the role for stereotactic navigation. Atlantoaxial transarticular screw fixation is highly effective in achieving fusion, and the complication rate is low when performed by properly trained surgeons.

Adolescent↗

PubMed2005

Metastatic spinal cord compression.

Approximately 70% of cancer patients have metastatic disease at death. The spine is involved in up to 40% of those patients. Spinal cord compression may develop in 5% to 10% of cancer patients and up to 40% of patients with preexisting nonspinal bone metastasis (>25,000 cases/y). Given the increasing survival times of patients with cancer, greater numbers of patients are likely to develop this complication. The role of surgery in the management of metastatic spinal cord compression is expanding. The management of metastatic spine disease can consist of a combination of surgery, radiation treatment, and chemotherapy. Treatment modalities are not mutually exclusive and must be individualized for patients evaluated in a multidisciplinary setting.

Combined Modality Therapy↗

PubMed2004

Cavernous hemangioma of the skull presenting with subdural hematoma. Case report.

Cavernous hemangioma of the calvaria is a very rare disease, and patients usually present with headaches or a visible skull deformity. Few reports of patients presenting with intradiploic or epidural hemorrhages are found in the literature. No case of an intradural hemorrhage from a cavernous hemangioma of the skull has been reported to date. The authors present the case of a 50-year-old man in whom a symptomatic subdural hematoma (SDH) resulting from a cavernous hemangioma of the calvaria had hemorrhaged and eroded through the inner table of the skull and dura mater. The patient underwent surgery for evacuation of the SDH and resection of the calvarial lesion. Postoperatively, the patient experienced immediate relief of his symptoms and had no clinical or radiological recurrence. Calvarial cavernous hemangiomas should be considered in the differential diagnosis of nontraumatic SDHs. Additionally, skull lesions that present with intracranial hemorrhages must be identified and resected at the time of hematoma evacuation to prevent recurrences.

Bone Neoplasms↗

PubMed2004

The role of thoracoscopic spinal surgery in the management of pyogenic vertebral osteomyelitis.

STUDY DESIGN: Case report, operative technique. OBJECTIVES: Vertebral osteomyelitis is frequently associated with elderly and debilitated patients who have significant medical comorbidities. If surgical debridement is contemplated, an open anterior approach like a thoracotomy can be associated with significant complications in this patient population. Thus, patients with vertebral osteomyelitis who need surgery may benefit from minimal invasive techniques that avoid the complications of more extensive open approaches. We performed thoracoscopic spinal surgery in patients with pyogenic vertebral osteomyelitis, attempting to reduce the morbidity attributable to standard open thoracotomy surgery. METHODS: The technique and results of minimally invasive thoracoscopic spinal surgery for pyogenic vertebral osteomyelitis in three patients, including radical debridement and anterior spinal reconstruction, are presented. RESULTS: Radical debridement and anterior spinal reconstruction are feasible via endoscopic approach. Standard thoracotomy or thoracoabdominal approaches associated with high morbidity can be avoided, even for fusion across multiple levels. Conversion to open technique was not necessary in this study. There was no recurrence of infection or loss of reduction during the follow-up period. Operative time and blood loss of endoscopic technique were comparable to open technique. CONCLUSIONS: The cases clearly demonstrate the feasibility and efficacy of thoracoscopic spinal surgery in the management of pyogenic vertebral osteomyelitis. Debridement, decompression of the spinal canal, interbody fusion, and anterior spinal fixation can be performed via endoscopic approach.

Adult↗

PubMed2004

Syndrome of inappropriate secretion of antidiuretic hormone and hyponatremia after spinal surgery.

Hyponatremia caused by an inappropriately high level of antidiuretic hormone secretion after spinal surgery is an uncommon and self-limiting phenomenon that resolves within 2 or 3 weeks. During the early postoperative period, the patient's urine output and serum level of sodium should be monitored closely to prevent possible serious complications of the syndrome of inappropriate secretion of antidiuretic hormone. Symptoms vary depending on the severity of the hyponatremia and can range from mild headache, muscle cramps, nausea, and vomiting to convulsions, coma, and death. Treatment options include fluid restriction, oral intake of salt, and hypertonic saline. It is important that spine surgeons recognize this phenomenon early and treat it appropriately and conservatively to prevent possible serious complications.

Adult↗

PubMed2004

Spinal epidural lipomatosis: a review of its causes and recommendations for treatment.

Spinal epidural lipomatosis is most commonly observed in patients receiving long-term exogenous steroid therapy, but can also be seen in patients with endogenous steroid overproduction, obesity, or idiopathic disease. With this condition, there is hypertrophy of the epidural adipose tissue, causing a narrowing of the spinal canal and compression of neural structures. A majority of patients will present with progressive myelopathy, but radicular symptoms are also common. Conservative treatment--weaning from steroids or weight loss--can reverse the hypertrophy of the adipose tissue and relieve the neural compression. If conservative management fails, surgery with decompressive laminectomy is also very successful at improving the patient's neurological symptoms.

Disease Progression↗

PubMed2004

Embolization of metastatic spinal tumors.

Embolization is a safe and valuable primary and adjunctive treatment option for metastatic spinal tumors. Close consultation between the neurosurgeon, the oncologist, the radiation oncologist, and the interventionalist should lead to more applications of embolization techniques,thereby enhancing the treatment of metastatic spinal lesions. The development of newer embolic agents with chemotherapeutic properties should add to the efficacy of embolization for metastatic spinal disease.

Blood Loss, Surgical↗

PubMed2004

Surgical management of cervical spinal metastasis: anterior reconstruction and stabilization techniques.

Anterior cervical corpectomy followed by reconstruction and stabilization is an effective strategy in the management of spinal metastasis in some patients. Various techniques are available in the armamentarium of the spine tumor surgeon. In patients with a limited life expectancy,reconstruction with PMMA achieves immediate stability and thus obviates the need for an external orthosis and allows for early mobilization. The addition of anterior cervical plate fixation provides extra support to prevent distraction failure. In some cases, posterior stabilization may be necessary to achieve adequate stability.

Bone Cements↗

PubMed2004

The lateral extracavitary approach to the thoracic and lumbar spine.

The LECA is a technically challenging procedure with a steep learning curve. It is one of the most versatile approaches to the spine, however,with a logical sequence of maneuvers that can be combined to adapt the LECA for many different spinal procedures that need to be performed for decompression of the spinal cord and reconstruction of the spinal column in cancer patients.

Decompression, Surgical↗

PubMed2004

Minimally invasive treatments for metastatic tumors of the spine.

Minimally invasive approaches are finding their way into all aspects of metastatic spinal disease from diagnosis to treatment of patients who are diagnosed early in their course as well as patients with multifocal metastases. For patients who are found to have asymptomatic spinal metastases, diagnosis is important to guide management and treatment so as to prevent future morbidity. These patients also now have the option of less invasive techniques for resection,reconstruction, and stabilization, including endoscopy and less invasive surgical approaches. Patients who are treated later in their course, with multifocal metastatic disease also have more options for palliation of pain and for stability,including vertebroplasty/kyphoplasty and radio-frequency tumor ablation as well as some of the percutaneous methods of stabilization described previously. As techniques evolve and im-prove, patients will continue to have more access to less invasive options for treatment of spinal metastases.

Electrocoagulation↗