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Jason T. Miller, Scott Y. Rahimi, and Mark Lee

Before advancements in infection control, only conditions that brought patients near death warranted the risk of surgical intervention. If patients survived the operation, infection was nearly inevitable and death by overwhelming sepsis was knocking at their door. In the late 19th century, with the development of germ theory by Louis Pasteur and its subsequent application to surgical sterility by Joseph Lister, surgeons were able to operate with a substantially reduced risk of infection. Consequently, surgeons became more confident and began to explore more extravagant procedures, including elective operations within the cranial vault. As scientific knowledge expanded in the 20th century, so did the advancement of infection control with the use of prophylactic antibiotic drugs, heat sterilization of instruments, and microbial barriers. Recent reports have placed the rate of complications due to infection between 0.75 and 2.32% for intracranial operations.

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David John Yeh, Richard B. Hessler, and Mark R. Lee

Primary leiomyosarcoma of the central nervous system is rare and has been described both de novo and following temporally remote radiotherapy for a different unrelated malignancy. The authors report the case of a 42-year-old man in whom 60Co radiation treatment had been performed for an unknown primary mass in the brainstem 25 years previously. He presented with progressive neurological deterioration after undergoing many years of conservative therapy. A stereotactic biopsy sampling procedure was performed, and examination of the left cerebral pedunculopontine lesion revealed a spindle cell neoplasm. Histopathological and immunohistochemical examination of the tumor obtained from definitive resection suggested leiomyosarcomatous transformation of ganglioglioma.

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Joseph R. Smith, Don W. King, Yong D. Park, Mark R. Lee, Gregory P. Lee, and Patrick D. Jenkins

Object. The purpose of this study was to determine if magnetic source (MS) imaging could provide useful information in the planning and performance of gamma knife radiosurgery (GKS) for epilepsy.

Methods. Magnetic source imaging of interictal epileptiform dipoles was studied in 53 epilepsy surgery candidates. All patients underwent volumetric magnetic resonance (MR) imaging. Subsequently, magnetoencephalography (MEG) was performed using single or dual 37—channel units. The MR images and MEG recordings were then coregistered to produce the MS imaging data. Magnetic source imaging epileptiform data were reviewed in a blinded fashion and spatial distributions were classified as focal, regional, multiple, scattered, or none. Postresection operative photographs were compared with MS image results to determine whether extensive or partial/no resection of the MS image focus had been accomplished. Magnetoencephalography dipoles were identified in 47 patients (89%), in 46 of whom the lesions were resected. This included 20 (80%) of 25 anterior temporal lobe (ATL) cases, and 26 (93%) of 28 extratemporal lobe (ETL) cases. Of the six patients who underwent extensive ATL resections, three (50%) were seizure free. Of 14 patients who underwent partial/no resection of the ATL, seven (50%) were seizure free. There was no clear relation between MS image spatial distribution and surgery-related outcome. Of the seven ATL cases with hippocampal atrophy, five patients (71%) were seizure free. Of 12 ETL cases (three lesional), 10 patients (83%) were seizure free. Of 14 patients who underwent partial/no ETL resections (three lesional), two (14%) were seizure free. Of five nonlesional ETL cases with focal MS image dipoles, four patients (80%) were seizure free. Of five nonlesional ETL cases with regional dipoles, three patients (60%) were seizure free. Of eight ETL cases with multiple MS image dipoles, two patients (25%) were seizure free. Spatial agreement of MS imaging and electrographic data had no apparent effect on outcome of either ATL or ETL cases.

Conclusions. Nonlesional ETL cases with focal (and in some cases multiple or regional) epileptiform MS image dipole distributions benefit significantly from inclusion of the MS image epileptiform focus in the resections. Nonlesional ETL cases suitable for GKS may similarly benefit from including the MS image focus in the irradiated area.

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Alan T. Villavicencio, Sigita Burneikiene, E. Lee Nelson, Ketan R. Bulsara, Mark Favors, and Jeffrey Thramann

Object. Recombinant human bone morphogenetic protein—2 (rhBMP-2) is being increasingly used for spinal fusion. There are few data regarding its clinical safety, effectiveness, and clinical outcome when applied on an absorbable collagen sponge (ACS) in conjunction with allograft for transforaminal lumbar interbody fusion (TLIF).

Methods. Seventy-four consecutive patients undergoing TLIF for degenerative disc disease were divided into five groups depending on whether the patient underwent a minimally invasive or open approach, as well as the number of spinal levels surgically treated. Surgery-related data, fusion results, complications, and clinical outcome were evaluated. The mean follow-up duration was 20.6 months (range 14–28 months). The radiographic fusion rate was 100% at 12 and 24 months after the surgery. No bone overgrowth or other complications related to BMP use were demonstrated.

Conclusions. Analysis of the results demonstrated that TLIF combined with a BMP-2—soaked ACS is a feasible, effective, and safe method to promote lumbar fusion. There were no significant intergroup differences in clinical outcome between patients who underwent open compared with minimally invasive procedures. Patient satisfaction rates, however, were higher in the minimally invasive procedure group. The efficacy of BMP-2 was not dependent on which approach was used or the number of spinal levels that were treated.

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Sydney M. Hester, John F. Fisher, Mark R. Lee, Samuel Macomson, and John R. Vender

Object

Intrathecal baclofen therapy has been used successfully for intractable spasticity in children with cerebral palsy. Infections are rare, but they are potentially life threatening if complicated by bacteremia or meningitis. Treatment without removal of the system is desirable if it can be done safely and effectively.

Methods

The authors reviewed the records of 207 patients ranging from 3 to 18 years of age with cerebral palsy who underwent placement or revision of a baclofen pump. They identified 38 patients with suspected or documented infectious complications. Initial attempts were made to eradicate infection with the devices in situ in all patients. Methods and effectiveness of pump salvage were evaluated.

Results

Of the 38 patients identified, 13 (34.2%) had documented infections; 11 had deep wound/pocket empyemas and 2 had meningitis. Eight patients with deep wound infections received intravenous antibiotics alone. All required pump explantation. The remaining 3 patients underwent a washout procedure as well; the infection was cured in 1 patient. Both patients with meningitis received intravenous and intrathecal antibiotics, and both required device explantation. In addition, 25 patients (65.8%) had excessive or increasing wound erythema. No objective criteria to document a superficial infection were present. The wounds were considered suspicious and were managed with serial examinations and oral antibiotics. The erythema resolved in 24 of the 25 patients.

Conclusions

In general, observation, wound care, and oral antibiotics are sufficient for wounds that are suspicious for superficial infection. For deep-seated infection, antibiotic therapy alone is generally insufficient and explantation is required. Washout procedures can be considered, but failures are common.

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John R. Vender, Sydney Hester, Jennifer L. Waller, Andy Rekito, and Mark R. Lee

Object

Intrathecal baclofen therapy is an effective means of treating intractable spasticity and dystonia in the pediatric and adult population. The authors present a review of complications encountered in a series of 314 pump and catheter-related procedures. The identification and management of these complications will be reviewed. The authors will also identify populations that may be at increased risk for complications.

Methods

A retrospective review was performed of all procedures undertaken during the last 5 years by two surgeons at the authors' institution. Postoperative complications were reviewed.

A total of 314 surgical procedures (226 pediatric and 88 adult) were performed in 195 pediatric and adult patients. This included 171 new pump and catheter implants (116 pediatric and 55 adult), 26 elective pump replacements due to end of battery life (15 pediatric and 11 adult), five elective pump repositionings per physiatrist request (three pediatric and two adult), 14 elective catheter repositionings (10 pediatric and four adult), and two normal pediatric catheter explorations. Surgical procedures for complication management included seven pump revisions (five pediatric and two adult), 48 catheter revisions (38 pediatric and 10 adult), and 41 wound revisions (37 pediatric and four adult). The majority of adult pumps were implanted subdermally, whereas in pediatric patients they were placed subfascially. In general, intrathecal catheters were placed under fluoroscopic guidance with the catheter tip placed at T-1 to T-2 for spastic quadriplegia, T-6 to T-10 for spastic diplegia, and midcervical for dystonia. No significant intraoperative complications were encountered. Overall, there was a statistically significantly higher percentage of procedures for overall complication management and wound complication management in pediatric patients compared with adult patients.

Conclusions

Intrathecal baclofen therapy is a highly effective treatment option for patients with medically refractory spasticity. The catheter, pump, and wound are subject to numerous complications both at the time of implantation and throughout the life of the implanted system. Careful technique, close observation, and aggressive evaluation and correction of problems can reduce the incidence and severity of the complications when they occur.

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Edward C. Nemergut and Mark E. Shaffrey

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Mark Lee, Ali R. Rezai, Rick Abbott, Daniel H. Coelho, and Fred J. Epstein

✓ Spinal cord lipomas are rare lesions, accounting for approximately 1% of all spinal cord tumors. True intramedullary spinal cord lipomas are extremely rare and are represented in the literature as scattered, single case reports. The authors present a series of six patients with intramedullary spinal cord lipomas managed at our institution from July, 1985 to July, 1993. The patients' ages ranged from 8 to 45 years. Four patients presented with newly diagnosed tumors and two had undergone previous surgery. Patients usually presented with long histories of disability followed by rapid progression of their symptoms. Most patients were in poor neurological condition on presentation. Presenting symptoms included spinal pain, dysesthetic sensory changes, gait difficulties, weakness, and incontinence. Three patients had cervical tumors, two had cervicothoracic tumors, and one patient had a thoracic tumor. Diagnostic studies, including magnetic resonance imaging, were obtained in all patients. No patient exhibited any form of spinal dysraphism or had a dural defect. All patients underwent decompressive, subtotal resections of 40% to 70% of their lesions. Follow-up times ranged from 12 to 96 months. All patients had resolution of their pain, but they generally showed no neurological improvement. As of their most recent follow-up visit, none of the patients was neurologically normal; three can function independently, although with neurological deficits. The other three patients cannot function independently and have severe neurological deficits. The authors conclude that patients with intramedullary spinal cord lipoma who present with significant neurological compromise have a very poor prognosis with regard to neurological function and generally show no improvement with surgical resection.

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Scott Y. Rahimi, E. Andrew Stevens, David John Yeh, Ann Marie Flannery, Haroon Fiaz Choudhri, and Mark R. Lee

The atlantoaxial region has been extensively described as a spinal segment especially prone to injury in children. In this clinical review, the authors evaluate and summarize the management of 23 pediatric cases of atlantoaxial instability treated between March 1990 and October 2002. Four broad categories of atlantoaxial problems were observed—atlantoaxial rotatory subluxation in six patients, anterior–posterior atlantoaxial instability caused by ligamentous injury or congenital ligamentous laxity (10 patients), atlantoaxial fracture with or without dislocation (five patients), and atlantooccipital dislocation (two patients). Most cases (60.9%) were treated without surgical intervention, resulting in excellent outcomes; however, 21.7% of cases were treated with a cervical halo (mean patient age 72.6 months) alone for 3 months. Various techniques of surgical stabilization including transarticular screws with sublaminar wiring, trans-oral decompression with posterior plating, and laminectomy with Steinmann pin occipital–cervical fusion were used with good results. Both patients with atlantooccipital dislocation underwent immediate Locksley occipital–cervical fusion, with marked neurological improvement. Individualized case management must be based on clinical presentation, with internal fixation being the last resort.

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Richard S. Polin, Murad Bavbek, Mark E. Shaffrey, Kevin Billups, Christopher A. Bogaev, Neal F. Kassell, and Kevin S. Lee

Object. The goal of this study was to explore whether the levels of soluble adhesion molecules were elevated in cerebrospinal fluid (CSF) after subarachnoid hemorrhage (SAH). This association was suggested by the known inflammatory response in vasospasm and the role of vascular adhesion molecules in regulating leukocytic adhesion to, and migration across, vascular endothelium.

Methods. A prospective analysis was performed on CSF samples obtained in 17 patients who had suffered a recent aneurysmal SAH and in 16 control patients by using quantitative enzyme-linked immunosorbent assays for E-selectin, intercellular adhesion molecule—1 (ICAM—1), vascular adhesion molecule—1 (VCAM-1), and L-selectin.

Levels of soluble forms of E-selectin (p = 0.0013), ICAM-1 (p = 0.0001), and VCAM-1 (p = 0.048) were found to be elevated in the CSF of patients after SAH compared with levels in the CSF of normal controls, patients with unruptured aneurysms, and patients tested months after SAH occurred. In addition, individual patients tested at the time of their initial ictus demonstrated a fall in adhesion molecule levels over time. Levels of E-selectin (p = 0.044) were highest in patients who later developed moderate or severe vasospasm.

Conclusions. Adhesion molecules are known to be involved in white cell adherence to the endothelium and subsequent diapedesis and migration in which a role in initiation of tissue damage is postulated. The authors have demonstrated the elevation of three adhesion molecules, with severely elevated levels of E-selectin seen in patients who later develop vasospasm. A correlation with a role of vascular adhesion molecules in the pathogenesis of cerebral vasospasm is suggested.