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Gregory C. Wiggins, Michael J. Rauzzino, Henry M. Bartkowski, Russ P. Nockels and Christopher I. Shaffrey

Object. The authors sought to analyze prospectively the outcome of surgery for complex spinal deformity in the pediatric and young adult populations.

Methods. The authors evaluate all pediatric and adolescent patients undergoing operative correction of complex spinal deformity from December 1997 through July 1999. No patient was lost to follow-up review (average 21.1 months). There were 27 consecutive pediatric and adolescent patients (3–20 years of age) who underwent 32 operations. Diagnoses included scoliosis (18 idiopathic, five nonidiopathic) and four severe kyphoscoliosis. Operative correction and arthrodesis were achieved via 21 posterior approaches (Cotrel-Dubousset-Horizon), seven anterior approaches (Isola or Kaneda Scoliosis System), and two combined approaches. Operative time averaged 358 minutes (range 115–620 minutes). Blood loss averaged 807 ml (range 100–2000 ml). Levels treated averaged 9.1 (range three–16 levels). There was a 54% average Cobb angle correction (range 6–82%). No case was complicated by the patient's neurological deterioration, loss of somatosensory evoked potential monitoring, cardiopulmonary disease, donor-site complication, or wound breakdown. There was one case of hook failure and one progression of deformity beyond the site of surgical instrumentation that required reoperation. There were 10 minor complications that did not significantly affect patient outcome. No patient received undirected banked blood products. There was a significant improvement in cosmesis, and no patient experienced continued pain postoperatively. All patients have been able to return to their preoperative activities.

Conclusions. Compared with other major neurosurgical operations, segmental instrumentation for pediatric and adolescent spinal deformity is a safe procedure with minimal morbidity and there is a low risk of needing to use allogeneic blood products.

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Shivanand P. Lad, Chirag G. Patil, Christopher Ho, Michael S. B. Edwards and Maxwell Boakye

Object

Previous investigations of health outcome after spinal surgery for tethered cord syndrome (TCS) have been single-institution studies. The aim of this study was to report inpatient complications and outcomes on a nationwide level.

Methods

The Nationwide Inpatient Sample (NIS) was used to identify patients who underwent spinal surgery for TCS in the US between 1993 and 2002. Patients who had a primary diagnosis of TCS (ICD-9 742.59) and also underwent spinal laminectomies were included in this study. Multivariate analysis was performed to analyze the effects of patient and hospital characteristics on variables such as mortality rate, nonfatal complications, LOS, and adverse outcomes in general (defined as death or discharge to an institution rather than home).

Results

The NIS sample included data on 9733 patients with TCS who underwent surgery. The means for mortality rate, complication rate, and LOS, respectively, were 0.0005%, 9.48%, and 5.6 days. Postoperative hemorrhages or hematomas (mean rate 2.3%) were the most common complications reported. Age and complications were the only significant predictors of adverse outcome on multivariate analysis. Patients older than 65 years had a threefold increase in risk of adverse outcome compared with patients 18 to 44 years of age. On average, one postoperative complication led to a 3-day increase in mean LOS and added more than $9000 to hospital charges.

Conclusions

This study provides a national perspective on inpatient complications and outcomes after spinal surgery for TCS in the United States. The authors have demonstrated the impact of age, complications, and medical comorbidities on the outcome of surgery for patients with this common disorder.

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Christopher B. Michael, Andrew G. Lee, James R. Patrinely, Samuel Stal and J. Bob Blacklock

✓ The authors present a case of visual loss associated with fibrous dysplasia of the anterior skull base and the surgical management of this case. Preoperative computerized tomography scanning in this patient demonstrated a patent optic foramen and a rapidly growing cystic mass within the orbit, which was responsible for the patient's visual loss. A literature review revealed that this case is typical, in that cystic mass lesions of various types are frequently responsible for visual loss associated with fibrous dysplasia. The authors did not find significant evidence in the literature to support the notion that visual loss associated with fibrous dysplasia is the result of progressive optic canal stenosis, thus raising questions about the value of prophylactic optic canal decompression. Instead, as demonstrated by this case and those uncovered in the literature review, most instances of visual loss result from the rapid growth of mass lesions of cystic fibrous dysplasia, mucoceles, or hemorrhage. Findings of the literature review and the present case of fibrous dysplasia of the anterior skull base support a role for extensive surgical resection in these cases and indicate a need for additional prospective analysis of a larger number of patients with this disease.

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Christopher B. T. Adams, Michael R. Fearnside and Sean A. O'Laoire

✓ Serial postoperative angiograms were performed in 28 patients with intracranial aneurysms, 26 of whom had presented with a subarachnoid hemorrhage. The clinical state and intracranial pressure (ICP) were also measured. Angiograms were performed in the ward using a cannula, which was passed into the proximal external carotid artery via the superficial temporal artery. Measurements of the vessel diameters were made, with the preoperative angiogram as a baseline. Patients could be placed into one of five groups depending on the presence or absence of significant arterial spasm, the clinical state of the patient, and the normality or otherwise of the ICP. No patient's condition deteriorated without an elevated ICP and/or significant arterial spasm. The study shows that this spasm is usually associated with a poor clinical state if it reaches a maximum 8 to 12 hours after the operation, although the clinical deterioration is not apparent for a further 6 to 12 hours. Knowledge of the natural history of postoperative arterial spasm may allow earlier treatment of the spasm, which may be more successful than delaying treatment until clinical deterioration has occurred. The worth of the varied drugs proposed for the treatment of spasm may be assessed using this type of protocol.

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Christopher B. Shields and Michael West

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Michael P. Kelly, Michael A. Kallen, Christopher I. Shaffrey, Justin S. Smith, Douglas C. Burton, Christopher P. Ames, Virginie Lafage, Frank J. Schwab, Han Jo Kim, Eric O. Klineberg, Shay Bess and the International Spine Study Group

OBJECTIVE

After using PROsetta Stone crosswalk tables to calculate Patient-Reported Outcomes Measurement Information System (PROMIS) Physical Function (PF) and Pain Interference (PI) scores, the authors sought to examine 1) correlations with Scoliosis Research Society–22r (SRS-22r) scores, 2) responsiveness to change, and 3) the relationship between baseline scores and 2-year follow-up scores in adult spinal deformity (ASD).

METHODS

PROsetta Stone crosswalk tables were used to converted SF-36 scores to PROMIS scores for pain and physical function in a cohort of ASD patients with 2-year follow-up. Spearman correlations were used to evaluate the relationship of PROMIS scores with SRS-22r scores. Effect size (ES) and adjusted standardized response mean (aSRM) were used to assess responsiveness to change. Linear regression was used to evaluate the association between baseline scores and 2-year follow-up scores.

RESULTS

In total, 425 (425/625, 68%) patients met inclusion criteria. Strong correlations (all |r| > 0.7, p < 0.001) were found between baseline and 2-year PROMIS values and corresponding SRS-22r domain scores. PROMIS-PI showed a large ES (1.09) and aSRM (0.88), indicating good responsiveness to change. PROMIS-PF showed a moderate ES (0.52) and moderate aSRM (0.69), indicating a moderate responsiveness to change. Patients with greater baseline pain complaints were associated with greater pain improvement at 2 years for both SRS-22r Pain (B = 0.39, p < 0.001) and PROMIS-PI (B = 0.45, p < 0.001). Higher functional scores at baseline were associated with greater average improvements in both SRS-22r Activity (B = 0.62, p < 0.001) and PROMIS-PF (B = 0.40, p < 0.001).

CONCLUSIONS

The authors found strong correlations between the SRS-22r Pain and Activity domains with corresponding PROMIS-PI and -PF scores. Pain measurements showed similar and strong ES and aSRM while the function measurements showed similar, moderate ES and aSRM at 2-year follow-up. These data support further exploration of the use of PROMIS–computer adaptive test instruments in ASD.

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Michael P. Kelly, Lawrence G. Lenke, Jakub Godzik, Ferran Pellise, Christopher I. Shaffrey, Justin S. Smith, Stephen J. Lewis, Christopher P. Ames, Leah Y. Carreon, Michael G. Fehlings, Frank Schwab and Adam L. Shimer

OBJECTIVE

The authors conducted a study to compare neurological deficit rates associated with complex adult spinal deformity (ASD) surgery when recorded in retrospective and prospective studies. Retrospective studies may underreport neurological deficits due to selection, detection, and recall biases. Prospective studies are expensive and more difficult to perform, but they likely provide more accurate estimates of new neurological deficit rates.

METHODS

New neurological deficits were recorded in a prospective study of complex ASD surgeries (pSR1) with a defined outcomes measure (decrement in American Spinal Injury Association lower-extremity motor score) for neurological deficits. Using identical inclusion criteria and a subset of participating surgeons, a retrospective study was created (rSR1) and neurological deficit rates were collected. Continuous variables were compared with the Student t-test, with correction for multiple comparisons. Neurological deficit rates were compared using the Mantel-Haenszel method for standardized risks. Statistical significance for the primary outcome measure was p < 0.05.

RESULTS

Overall, 272 patients were enrolled in pSR1 and 207 patients were enrolled in rSR1. Inclusion criteria, defining complex spinal deformities, and exclusion criteria were identical. Sagittal Cobb measurements were higher in pSR1, although sagittal alignment was similar. Preoperative neurological deficit rates were similar in the groups. Three-column osteotomies were more common in pSR1, particularly vertebral column resection. New neurological deficits were more common in pSR1 (pSR1 17.3% [95% CI 12.6–22.2] and rSR1 9.0% [95% CI 5.0–13.0]; p = 0.01). The majority of deficits in both studies were at the nerve root level, and the distribution of level of injury was similar.

CONCLUSIONS

New neurological deficit rates were nearly twice as high in the prospective study than the retrospective study with identical inclusion criteria. These findings validate concerns regarding retrospective cohort studies and confirm the need for and value of carefully designed prospective, observational cohort studies in ASD.

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Michael M. McDowell, Christopher P. Kellner, Sunjay M. Barton, Charles B. Mikell, Eric S. Sussman, Simon G. Heuts and E. Sander Connolly

In this report, the authors sought to summarize existing literature to provide an overview of the currently available techniques and to critically assess the evidence for or against their application in intracerebral hemorrhage (ICH) for management, prognostication, and research. Functional imaging in ICH represents a potential major step forward in the ability of physicians to assess patients suffering from this devastating illness due to the advantages over standing imaging modalities focused on general tissue structure alone, but its use is highly controversial due to the relative paucity of literature and the lack of consolidation of the predominantly small data sets that are currently in existence. Current data support that diffusion tensor imaging and tractography, diffusion-perfusion weighted MRI techniques, and functional MRI all possess major potential in the areas of highlighting motor deficits, motor recovery, and network reorganization. Novel clinical studies designed to objectively assess the value of each of these modalities on a wider scale in conjunction with other methods of investigation and management will allow for their rapid incorporation into standard practice.

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Michael Safaee, Andrew T. Parsa, Nicholas M. Barbaro, Dean Chou, Praveen V. Mummaneni, Philip R. Weinstein, Tarik Tihan and Christopher P. Ames

OBJECT

Intradural extramedullary spine tumors represent two-thirds of all primary spine neoplasms. Approximately half of these are peripheral nerve sheath tumors, mainly neurofibromas and schwannomas. Given the rarity of this disease and, thus, the limited analyses of clinical outcomes, the authors examined the association of tumor location, extent of resection, and neurofibromatosis (NF) status with clinical outcomes.

METHODS

Patients were identified through a search of the University of California, San Francisco, neuropathology database and a separate review of current procedural terminology codes. Data recorded included patient age, patient sex, clinical presentation, presence of NF, tumor type, tumor location, extent of resection (gross-total resection [GTR] or subtotal resection [STR]), and clinical follow-up.

RESULTS

Of 221 tumors in 199 patients (mean age 45 years), 53 were neurofibromas, 163 were schwannomas, and 5 were malignant peripheral nerve sheath tumors. The most common presenting symptom was spinal pain (76%), followed by weakness (36%) and sensory abnormalities (34%). Mean symptom duration was 16 months. In terms of spinal location, neurofibromas were more common in the cervical spine (74% vs 27%, p < 0.001), and schwannomas were more common in the thoracic and lumbosacral spine (73% vs 26%, p < 0.001). Rates of GTR were lower for neurofibromas than schwannomas (51% vs 83%, p < 0.001), regardless of location. Rates of GTR were lower for cervical (54%) than thoracic (90%) and lumbosacral (86%) lesions (p < 0.001). NF was associated with lower rates of GTR among all tumors (43% vs 86%, p < 0.001). The mean follow-up time was 32 months. Recurrence/progression was more common for neurofibromas than schwannomas (17% vs 7%, p = 0.03), although the mean time to recurrence/progression did not differ according to tumor type (45 vs 53 months, p = 0.63). As expected, GTR was associated with lower recurrence rates (4% vs 22%, p < 0.001). According to multivariate analysis, cervical location (OR 0.239, 95% CI 0.110–0.520) and presence of NF (OR 0.166, 95% CI 0.054–0.507) were associated with lower rates of GTR. In a separate model, only GTR (OR 0.141, 95% CI 0.046–0.429) was associated with tumor recurrence.

CONCLUSIONS

Resection is an effective treatment for spinal nerve sheath tumors. Neurofibromas were found more commonly in the cervical spine than in other regions of the spine and were associated with higher rates of recurrence and lower rates of GTR than other tumor types, particularly in patients with NF Types 1 or 2. According to multivariate analysis, both cervical location and presence of NF were associated with lower rates of GTR. According to a second multivariate model, the only variable associated with tumor recurrence was extent of resection. Maximal safe resection remains ideal for these lesions; however, patients with cervical tumors or NF should be counseled about their increased risk for recurrence.

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Sven Berkmann, Sven Schlaffer, Christopher Nimsky, Rudolf Fahlbusch and Michael Buchfelder

Object

The loss of anatomical landmarks, frequently invasive tumor growth, and tissue changes make transsphenoidal reoperation of nonfunctioning pituitary adenomas (NFAs) challenging. The use of intraoperative MRI (iMRI) may lead to improved results. The goal of this retrospective study was to evaluate the impact of iMRI on transsphenoidal reoperations for NFA.

Methods

Between September 2002 and July 2012, 109 patients underwent reoperations in which 111 transsphenoidal procedures were performed and are represented in this study. A 1.5-T Magnetom Sonata Maestro Class scanner (Siemens) was used for iMRI. Follow-up iMRI scans were acquired if gross-total resection (GTR) was suspected or if no further removal seemed possible.

Results

Surgery was performed for tumor persistence and regrowth in 26 (23%) and 85 (77%) patients, respectively. On the initial iMRI scans, GTR was confirmed in 19 (17%) patients. Remnants were located as follows: 65 in the cavernous sinus (71%), 35 in the suprasellar space (38%), 9 in the retrosellar space (10%). Additional resection was possible in 62 (67%) patients, resulting in a significant volume reduction and increased GTR rate (49%). The GTR rates of invasive tumors on initial iMRI and postoperative MRI (poMRI) were 7% and 25%, respectively. Additional remnant resection was possible in 64% of the patients. Noninvasive tumors were shown to be totally resected on the initial iMRI in 31% of cases. After additional resection for 69% of the procedures, the GTR rate on poMRI was 75%. Transcranial surgery to resect tumor remnants was indicated in 5 (5%), and radiotherapy was performed in 29 (27%) patients. After GTR, no recurrence was detected during a mean follow-up of 2.2 ± 2.1 years.

Conclusions

The use of iMRI in transsphenoidal reoperations for NFA leads to significantly higher GTR rates. It thus prevents additional operations and reduces the number of tumor remnants. The complication rates do not exceed the incidences reported in the literature for primary transsphenoidal surgery. If complete tumor resection is not possible, iMRI guidance can facilitate tumor volume reduction.