Papers by Meic H Schmidt, MD, MBA
Surgical neurology international, 2016
Malignant peripheral nerve sheath tumors (MPNSTs) of the brachial plexus have unique radiographic... more Malignant peripheral nerve sheath tumors (MPNSTs) of the brachial plexus have unique radiographic and clinical findings. Patients often present with progressive upper extremity paresthesias, weakness, and pain. On magnetic resonance (MR) imaging, lesions are isointense on T1-weighted and hyperintense on T2-weighted sequences, while also demonstrating marked enhancement on MR studies with gadolinium diethylenetriamine pentaacetic acid. On the basis of their characteristic MR imaging features and rapid clinical progression, two brachial plexus lesions proved to be organizing hematomas rather than MPNST. A 51-year-old male and a 31-year-old female were both assessed for persistent and worsened left-sided upper extremity pain, paresthesias, and weakness. In both cases, the MR imaging of the brachial plexus demonstrated an extraspinal enhancing lesion located within the left C7-T1 neuroforamina. Although the clinical and radiographic MR features for these 2 patients were consistent with ...
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Manual of Spine Surgery, 2012
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Seminars in Spine Surgery, 2011
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Spine, Oct 15, 2009
Clinically based systematic review. To define optimal clinical care for primary spinal aggressive... more Clinically based systematic review. To define optimal clinical care for primary spinal aggressive "benign" osseous neoplasms using a systematic review with expert opinion. Predefined focused questions on treatment of osteoblastomas, aneurysmal bone cysts and giant cell tumors were refined by a panel of spine oncology surgeons, medical and radiation oncologist. Keywords were searched through Medline and pertinent abstracts and articles obtained. The quality of literature was rated as high, moderate, low or very low. Based on literature review and expert opinion recommendations were composed through the GRADE system and rated as either strong or weak. The literature searches revealed very low quality evidence with no prospective or randomized studies. There are a limited number of patients with aggressive primary osseous tumors. The osteoblastoma initial search identified 211 articles of which 17 were pertinent to the spinal questions. The aneurysmal bone cysts initial search revealed 482 articles initially of which 6 were pertinent; and the search on giant cell tumors identified 178 articles of which only 8 were focused on the predefined treatment questions. Spinal aggressive benign osseous neoplasms have varying histology. Despite these differences surgical treatment should be directed at gross resection of the tumor, understanding that this may be limited by anatomic confines and the potential for morbidity.
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Spine, Sep 1, 2010
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Http Dx Doi Org 10 3171 2010 3 Spine09267, Jul 23, 2010
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Journal of Neurosurgery Spine, Jul 1, 2007
The thoracic duct along with the cisterna chyli is a major lymphatic pathway near the anterior th... more The thoracic duct along with the cisterna chyli is a major lymphatic pathway near the anterior thoracolumbar spine. Despite the fragile nature of the lymphatic system and its proximity to the spinal column, chylorrhea is rarely encountered by spine surgeons. The authors present a unique case of chylorrhea associated with a left thoracoscopic, transdiaphragmatic discectomy and fusion for a T12-L1 herniated disc. The anomalous location of the thoracic duct at the left lateral vertebral column contributes to this unusual complication.
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ABSTRACT
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Spine, Jan 2, 2015
Retrospective database review OBJECTIVE.: To compare data on various pain and functional outcomes... more Retrospective database review OBJECTIVE.: To compare data on various pain and functional outcomes for patients who underwent minimally invasive transforaminal lumbar interbody fusion (MiTLIF) and those who had open TLIF to better delineate which patients may benefit from each procedure. TLIF is a highly successful technique for the treatment of patients with degenerative instability or deformity. Minimally invasive approaches have been developed in an effort to improve outcomes by reducing tissue trauma and minimizing surgical time and blood loss. Although these approaches have been compared in the literature, there continues to be debate about which patients may benefit from each procedure, and there is a dearth of information regarding short-term outcomes such as disposition status. We used the National Neurosurgery Quality and Outcomes Database (N2QOD) to assess outcomes of patients who underwent open or MiTLIF at a single institution from 2012 to 2014. Primary outcomes included ...
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Frontiers in Surgery, 2015
Pelvic fixation with S2-alar-iliac (S2AI) screws can increase the rigidity of a lumbosacral const... more Pelvic fixation with S2-alar-iliac (S2AI) screws can increase the rigidity of a lumbosacral construct, which may promote bone healing, improve antibiotic delivery to infected tissues, and avoid L5-S1 pseudarthrosis. To describe the use of single-stage posterior fixation without debridement for the treatment of pyogenic vertebral diskitis and osteomyelitis (PVDO) at the lumbosacral junction. Technical report. We describe the management of PVDO at the lumbosacral junction in which the infection invaded the endplates, disk space, vertebrae, prevertebral soft tissues, and epidural space. Pedicle involvement precluded screw fixation at L5. Surgical management consisted of a single-stage posterior operation with rigid lumbopelvic fixation augmented with S2-alar-iliac screws and without formal debridement of the infected area, followed by long-term antibiotic treatment. At 2-year follow-up, successful fusion and eradication of the infection were achieved. PVDO at the lumbosacral junction may be treated successfully using rigid posterior-only fixation without formal debridement combined with antibiotic therapy.
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Journal of the National Comprehensive Cancer Network: JNCCN
Approximately 70% of cancer patients have metastatic disease at death. The spine is involved in u... more 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.
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Cancer control: journal of the Moffitt Cancer Center
Metastatic tumor in the spinal column is common, causing symptomatic spinal cord compression in a... more Metastatic tumor in the spinal column is common, causing symptomatic spinal cord compression in approximately 25,000 patients annually. Although surgical treatment of spinal metastases has become safer, less invasive, and more efficacious in recent years, there remains a subset of patients for whom other treatment modalities are needed. Stereotactic radiosurgery, which has long been used in the treatment of intracranial lesions, has recently been applied to the spine and enables the effective treatment of metastatic lesions. We review the evolution of stereotactic radiosurgery and its applications in the spine, including a description of two commercially available systems. Although a relatively new technique, the use of stereotactic radiosurgery in the spine has advanced rapidly in the past decade. Spinal stereotactic radiosurgery is an effective and safe modality for the treatment of spinal metastatic disease. Future challenges involve the refinement of noninvasive fiducial trackin...
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Neurosurgical Focus, 2015
Genetic alterations in the cells of intradural spinal tumors can have a significant impact on the... more Genetic alterations in the cells of intradural spinal tumors can have a significant impact on the treatment options, counseling, and prognosis for patients. Although surgery is the primary therapy for most intradural tumors, radiochemothera-peutic modalities and targeted interventions play an ever-evolving role in treating aggressive cancers and in addressing cancer recurrence in long-term survivors. Recent studies have helped delineate specific genetic and molecular differences between intradural spinal tumors and their intracranial counterparts and have also identified significant variation in therapeutic effects on these tumors. This review discusses the genetic and molecular alterations in the most common intradural spinal tumors in both adult and pediatrie patients, including nerve sheath tumors (that is, neurofibroma and schwannoma), meningioma, ependymoma, astrocytoma (that is, low-grade glioma, anaplastic astrocytoma, and glioblastoma), hemangioblastoma, and medulloblastoma. It also examines the genetics of metastatic tumors to the spinal cord, arising either from the CNS or from systemic sources. Importantly, the impact of this knowledge on therapeutic options and its application to clinical practice are discussed.
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Spine, 2015
Prospective observational studyObjective. To investigate the association of perioperative vitamin... more Prospective observational studyObjective. To investigate the association of perioperative vitamin D levels and nonunion rates and time to fusion in patients undergoing elective spine fusion. Although there is a clear link between bone mineral density and the risk of osteoporosis, it is unclear whether low vitamin D levels affect rates and timing of spinal fusion. Serum 25-OH vitamin D levels were measured perioperatively in adults undergoing elective spinal fusion between 2011 and 2012. Vitamin D levels <20 ng/mL were considered deficient. Univariate and multivariate logistic regression were performed to identify independent predictors of pseudarthrosis/nonunion within a minimum follow-up period of 12 months. Kaplan-Meier analysis was used to compare time to fusion between groups. Of the 133 patients, 31 (23%) demonstrated vitamin D deficiency. Mean patient age was 57±13 years; 44% were female and 94% were Caucasian. The cervical spine was fused in 49%, the lumbar spine in 47%, and the thoracic spine in 4%. Mean construct length was 2 levels (range 1-16). At 12-month follow-up, 112/133 (84%) patients demonstrated fusion (median time to fusion 8.4 months). Nonunion at 12 months was associated with vitamin D deficiency (20% of patients with adequate vitamin D level vs. 38% of vitamin D-deficient patients, p = 0.063). Kaplan-Meier survival analysis demonstrated time to fusion was significantly longer in the vitamin D-deficient group (12 vs. 6 months, p = 0.001). On multivariate analysis, vitamin D deficiency was an independent predictor of nonunion (OR 3.449, p = 0.045) when adjusted for age, sex, obesity, fusion length, location, graft type, smoking, and bone morphogenetic protein use. Vitamin D levels may affect nonunion rate and time to fusion. These results offer insight into the importance of the metabolic milieu for bony fusion as well as a potential avenue for therapeutic intervention.
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Journal of Neurosurgery: Spine, 2015
OBJECT The authors&am... more OBJECT The authors' objectives were to compare the rate of fusion after occipitoatlantoaxial arthrodesis using structural allograft with the fusion rate from using autograft, to evaluate correction of radiographic parameters, and to describe symptom relief with each graft technique. METHODS The authors assessed radiological fusion at 6 and 12 months after surgery and obtained radiographic measurements of C1-2 and C2-7 lordotic angles, C2-7 sagittal vertical alignments, and posterior occipitocervical angles at preoperative, postoperative, and final follow-up examinations. Demographic data, intraoperative details, adverse events, and functional outcomes were collected from hospitalization records. Radiological fusion was defined as the presence of bone trabeculation and no movement between the graft and the occiput or C-2 on routine flexion-extension cervical radiographs. Radiographic measurements were obtained from lateral standing radiographs with patients in the neutral position. RESULTS At the University of Utah, 28 adult patients underwent occipitoatlantoaxial arthrodesis between 2003 and 2010 using bicortical allograft, and 11 patients were treated using iliac crest autograft. Mean follow-up for all patients was 20 months (range 1-108 months). Of the 27 patients with a minimum of 12 months of follow-up, 18 (95%) of 19 in the allograft group and 8 (100%) of 8 in the autograft group demonstrated evidence of bony fusion shown by imaging. Patients in both groups demonstrated minimal deterioration of sagittal vertical alignment at final follow-up. Operative times were comparable, but patients undergoing occipitocervical fusion with autograft demonstrated greater blood loss (316 ml vs 195 ml). One (9%) of 11 patients suffered a significant complication related to autograft harvesting. CONCLUSIONS The use of allograft in occipitocervical fusion allows a high rate of successful arthrodesis yet avoids the potentially significant morbidity and pain associated with autograft harvesting. The safety and effectiveness profile is comparable with previously published rates for posterior C1-2 fusion using allograft.
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Journal of the National Comprehensive Cancer Network : JNCCN, 2012
Cancer-related fractures of the spine are different from osteoporotic ones, not only in pathogene... more Cancer-related fractures of the spine are different from osteoporotic ones, not only in pathogenesis but also in natural history and treatment. Higher class evidence now supports offering balloon kyphoplasty to a patient with cancer, provided that the pain is significant in intensity, has a positional character, and correlates to the area of the fractured vertebrae. Absence of clinical spinal cord compression and overt instability are paramount. Because of the frequent disruption of the posterior vertebral body cortex in these patients, the procedure should be performed by experienced operators who could also quickly perform an open decompression if cement extravasation occurs. Patients will benefit from vertebral augmentation, even in chronic malignant fractures. A biopsy should be routinely performed and a combination with radiation treatment would be beneficial in most cases.
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Neurosurgery clinics of North America, 2008
As more minimally invasive modalities for the diagnosis and treatment of primary spinal column tu... more As more minimally invasive modalities for the diagnosis and treatment of primary spinal column tumors are developed, patients increasingly have the option of procedures that reduce the risk for morbidity and mortality and shorten recovery times. This review demonstrates a wide range of innovative techniques used in the diagnosis and nonoperative and operative treatment of primary spinal tumors. Some techniques facilitate actual tumor resection, whereas others provide symptomatic relief and clinical improvements.
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Neurosurgery Clinics of North America, 2004
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International journal of oncology, 2011
Metastatic disease commonly occurs in the spine and incidence is likely to increase secondary to ... more Metastatic disease commonly occurs in the spine and incidence is likely to increase secondary to improved survival rates in many cancer patients. Despite published research on instability in patients with metastatic disease of the thoracolumbar spine, controversy exists regarding risk factors for instability and indications for surgical stabilization. The objective of this systematic review was to determine what defines instability and impending instability in patients with metastatic disease of the thoracic and lumbar spine. We systematically reviewed the medical literature in order to identify all the relevant studies concerning patients with metastatic involvement of T1-L5, in the domains of biomechanics, epidemiology, clinical issues, and radiographic parameters. Two independent observers performed study selection, methodological quality assessment, and data extraction in a blinded and objective manner for all the identified studies. We were then able to define the criteria to i...
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Case Reports in Neurological Medicine, 2012
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Papers by Meic H Schmidt, MD, MBA