Faculty Bibliography

OBJECTIVE:Camptocormia is a potentially debilitating condition in the progression of Parkinson's disease (PD). It is described as an abnormal forward flexion while standing that resolves when lying supine. Although the condition is relatively common, the underlying pathophysiology and optimal treatment strategy are unclear. In this study, the authors systematically reviewed the current surgical management strategies for camptocormia. METHODS:PubMed was queried for primary studies involving surgical intervention for camptocormia in PD patients. Studies were excluded if they described nonsurgical interventions, provided only descriptive data, or were case reports. Secondarily, data from studies describing deep brain stimulation (DBS) to the subthalamic nuclei were extracted for potential meta-analysis. Variables showing correlation to improvement in sagittal plane bending angle (i.e., the vertical angle caused by excessive kyphosis) were subjected to formal meta-analysis. RESULTS:The query resulted in 9 studies detailing treatment of camptocormia: 1 study described repetitive trans-spinal magnetic stimulation (rTSMS), 7 studies described DBS, and 1 study described deformity surgery. Five studies were included for meta-analysis. The total number of patients was 66. The percentage of patients with over 50% decrease in sagittal plane imbalance with DBS was 36.4%. A duration of camptocormia of 2 years or less was predictive of better outcomes (OR 4.15). CONCLUSIONS:Surgical options include transient, external spinal stimulation; DBS targeting the subthalamic nuclei; and spinal deformity surgery. Benefit from DBS stimulation was inconsistent. Spine surgery corrected spinal imbalance but was associated with a high complication rate.

INTRODUCTION:Brachytherapy is a major adjuvant modality for neoplasms, but few have trialed its use for spinal tumors. This study examines perioperative and oncologic outcomes of patients with malignant spinal tumors who underwent resection with intraoperative phosphorous-32 (P32) brachytherapy. METHODS:Consecutive adult patients who underwent P32 brachytherapy during malignant spinal tumor resection were retrospectively identified from 2014 to 2015. Complications, tumor recurrence, and survival were reviewed. A comprehensive review of the literature was performed. RESULTS:A total of 8 patients were included. Average age was 54.3 years, and 25.0% were males. Tumor types included metastatic leiomyosarcoma, chordoma, multifocal recurrent ependymomas, breast metastasis, malignant meningioma, and myxofibrosarcoma. One-half of patients underwent en bloc tumor resection. P32 plaques were applied to 2 sites per patient for mean 13.1 minutes per site with a goal penetration of 10 Gy to 1-mm depth. Perioperative complications occurred in 3 patients (37.5%), including a persistent cerebral spinal fluid leak, deep infection requiring reoperation, and sacral insufficiency fracture. At a mean 25.6 months follow-up, local recurrence rate was 25.0%, and overall survival was 75.0%. Mean time to recurrence was 14.4 months. Survival at 6, 12, 18, and 24 months was 100.0%, 100.0%, 85.7%, and 71.4%, respectively. CONCLUSIONS:The use of P32 is safe and feasible. P32 intraoperative brachytherapy does not seem to increase the rate of complications. The sample size of this series is small with heterogeneity in tumor type, but recurrence and survival outcomes seem promising compared with previous reports. Further clinical trials are needed.

OBJECTIVE Glioblastoma (GBM) is an aggressive brain malignancy with a short overall patient survival, yet there remains significant heterogeneity in outcomes. Although access to health care has previously been linked to impact on prognosis in several malignancies, this question remains incompletely answered in GBM. METHODS This study was a retrospective analysis of 354 newly diagnosed patients with GBM who underwent first resection at the authors' institution (2007-2015). RESULTS Of the 354 patients (median age 61 years, and 37.6% were females), 32 (9.0%) had no insurance, whereas 322 (91.0%) had insurance, of whom 131 (40.7%) had Medicare, 45 (14%) had Medicaid, and 146 (45.3%) had private insurance. On average, insured patients survived almost 2-fold longer (p < 0.0001) than those who were uninsured, whereas differences between specific insurance types did not influence survival. The adjusted hazard ratio (HR) for death was higher in uninsured patients (HR 2.27 [95% CI 1.49-3.33], p = 0.0003). Age, mean household income, tumor size at diagnosis, and extent of resection did not differ between insured and uninsured patients, but there was a disparity in primary care physician (PCP) status-none of the uninsured patients had PCPs, whereas 72% of insured patients had PCPs. Postoperative adjuvant treatment rates with temozolomide (TMZ) and radiation therapy (XRT) were significantly less in uninsured (TMZ in 56.3%, XRT in 56.3%) than in insured (TMZ in 75.2%, XRT in 79.2%; p = 0.02 and p = 0.003) patients. Insured patients receiving both agents had better prognosis than uninsured patients receiving the same treatment (9.1 vs 16.34 months; p = 0.025), suggesting that the survival effect in insured patients could only partly be explained by higher treatment rates. Moreover, having a PCP increased survival among the insured cohort (10.7 vs 16.1 months, HR 1.65 [95% CI 1.27-2.15]; p = 0.0001), which could be explained by significant differences in tumor diameter at initial diagnosis between patients with and without PCPs (4.3 vs 4.8 cm, p = 0.003), and a higher rate of clinical trial enrollment, suggesting a critical role of PCPs for a timelier diagnosis of GBM and proactive cancer care management. CONCLUSIONS Access to health care is a strong determinant of prognosis in newly diagnosed patients with GBM. Any type of insurance coverage and having a PCP improved prognosis in this patient cohort. Higher rates of treatment with TMZ plus XRT, clinical trial enrollment, fewer comorbidities, and early diagnosis may explain survival disparities. Lack of health insurance or a PCP are major challenges within the health care system, which, if improved upon, could favorably impact the prognosis of patients with GBM.

OBJECTIVE Three-column osteotomies are increasingly being used in the elderly population to correct rigid spinal deformities. There is hesitation, however, in performing the technique in older patients because of the high risk for blood loss, longer operative times, and complications. This study assesses whether age alone is an independent risk factor for complications and length of stay. METHODS All patients with thoracolumbar adult spinal deformity (ASD) who underwent 3-column osteotomy (vertebral column resection or pedicle subtraction osteotomy) performed by the senior author from 2006 to 2016 were identified. Demographics, clinical baseline, and surgical details were collected. Outcomes of interest included perioperative complication, ICU stay, and hospital stay. Bivariate and multivariate analyses were used to assess the association of age with outcomes of interest. RESULTS A total of 300 patients were included, and 38.3% were male. The mean age was 63.7 years: 10.3% of patients were younger than 50 years, 36.0% were 50-64 years, 45.7% were 65-79 years, and 8.0% were 80 years or older. The overall mean EBL was 1999 ml. The overall perioperative complication rate was 24.7%: 18.0% had a medical complication and 7.0% had a surgical complication. There were no perioperative or 30-day deaths. Age was associated with overall complications (p = 0.002) and medical-specific complications (p < 0.001); there were higher rates of overall and medical complications with increased age: 9.7% and 6.5%, respectively, for patients younger than 50 years; 16.7% and 10.2%, respectively, for patients 50-64 years; 31.4% and 22.6%, respectively, for patients 65-79 years; and 41.7% and 41.7%, respectively, for patients 80 years or older. However, after adjusting for relevant covariates on multivariate analysis, age was not an independent factor for perioperative complications. Surgical complication rates were similar among the 4 age groups. Longer ICU and total hospital stays were observed in older age groups, and age was an independent factor associated with longer ICU stay (p = 0.028) and total hospital stay (p = 0.003). ICU stays among the 4 age groups were 1.6, 2.3, 2.0, and 3.2 days for patients younger than 50 years, 50-64 years, 65-79 years, and 80 years or older, respectively. The total hospital stays stratified by age were 7.3, 7.7, 8.2, and 11.0 days for patients younger than 50 years, 50-64 years, 65-79 years, and 80 years or older, respectively. CONCLUSIONS Older age was associated with higher perioperative complication rates, but age alone was not an independent risk factor for complications following the 3-column osteotomy for ASD. Comorbidities and other unknown variables that come with age are likely what put these patients at higher risk for complications. Older age, however, is independently associated with longer ICU and hospital stays.

Juvenile ossifying fibroma (JOF) is a rare benign bone tumor that occurs most frequently in the craniofacial bones of children and young adults. There are few case reports that describe its involvement outside the craniofacial skeleton, especially within the spinal column. While JOF is classified as a benign lesion, it may be locally aggressive and demonstrate a high propensity for recurrence, even after resection. Definitive surgical management may be challenging in naive cases, but it is particularly challenging in recurrent cases and when extensive spinal reconstruction is warranted. In this report, the authors describe the diagnosis and surgical management of a 29-year-old man who presented with a large recurrent sacral trabecular-subtype JOF. A review of literature regarding JOFs, management of recurrent primary spinal tumors, and sacral reconstruction are discussed.

OBJECTIVE Proximal junctional kyphosis (PJK) is a well-recognized, yet incompletely defined, complication of adult spinal deformity surgery. There is no standardized definition for PJK, but most studies describe PJK as an increase in the proximal junctional angle (PJA) of greater than 10°-20°. Ligament augmentation is a novel strategy for PJK reduction that provides strength to the upper instrumented vertebra (UIV) and adjacent segments while also reducing junctional stress at those levels. METHODS In this study, ligament augmentation was used in a consecutive series of adult spinal deformity patients at a single institution. Patient demographics, including age; sex; indication for surgery; revision surgery; surgical approach; and use of 3-column osteotomies, vertebroplasty, or hook fixation at the UIV, were collected. The PJA was measured preoperatively and at last follow-up using 36-inch radiographs. Data on change in PJA and need for revision surgery were collected. Univariate and multivariate analyses were performed to identify factors associated with change in PJA and proximal junctional failure (PJF), defined as PJK requiring surgical correction. RESULTS A total of 200 consecutive patients were included: 100 patients before implementation of ligament augmentation and 100 patients after implementation of this technique. The mean age of the ligament augmentation cohort was 66 years, and 67% of patients were women. Over half of these cases (51%) were revision surgeries, with 38% involving a combined anterior or lateral and posterior approach. The mean change in PJA was 6° in the ligament augmentation group compared with 14° in the control group (p < 0.001). Eighty-four patients had a change in PJA of less than 10°. In a multivariate linear regression model, age (p = 0.016), use of hook fixation at the UIV (p = 0.045), and use of ligament augmentation (p < 0.001) were associated with a change in PJA. In a separate model, only ligament augmentation (OR 0.193, p = 0.012) showed a significant association with PJF. CONCLUSIONS Ligament augmentation represents a novel technique for the prevention of PJK and PJF. Compared with a well-matched historical cohort, ligament augmentation is associated with a significant decrease in PJK and PJF. These data support the implementation of ligament augmentation in surgery for adult spinal deformity, particularly in patients with a high risk of developing PJK and PJF.

OBJECTIVE There is ample evidence that extent of resection (EOR) is associated with improved outcomes for glioma surgery. However, it is often difficult to accurately estimate EOR intraoperatively, and surgeon accuracy has yet to be reviewed. In this study, the authors quantitatively assessed the accuracy of intraoperative perception of EOR during awake craniotomy for tumor resection. METHODS A single-surgeon experience of performing awake craniotomies for tumor resection over a 17-year period was examined. Retrospective review of operative reports for quantitative estimation of EOR was recorded. Definitive EOR was based on postoperative MRI. Analysis of accuracy of EOR estimation was examined both as a general outcome (gross-total resection [GTR] or subtotal resection [STR]), and quantitatively (5% within EOR on postoperative MRI). Patient demographics, tumor characteristics, and surgeon experience were examined. The effects of accuracy on motor and language outcomes were assessed. RESULTS A total of 451 patients were included in the study. Overall accuracy of intraoperative perception of whether GTR or STR was achieved was 79.6%, and overall accuracy of quantitative perception of resection (within 5% of postoperative MRI) was 81.4%. There was a significant difference (p = 0.049) in accuracy for gross perception over the 17-year period, with improvement over the later years: 1997-2000 (72.6%), 2001-2004 (78.5%), 2005-2008 (80.7%), and 2009-2013 (84.4%). Similarly, there was a significant improvement (p = 0.015) in accuracy of quantitative perception of EOR over the 17-year period: 1997-2000 (72.2%), 2001-2004 (69.8%), 2005-2008 (84.8%), and 2009-2013 (93.4%). This improvement in accuracy is demonstrated by the significantly higher odds of correctly estimating quantitative EOR in the later years of the series on multivariate logistic regression. Insular tumors were associated with the highest accuracy of gross perception (89.3%; p = 0.034), but lowest accuracy of quantitative perception (61.1% correct; p < 0.001) compared with tumors in other locations. Even after adjusting for surgeon experience, this particular trend for insular tumors remained true. The absence of 1p19q co-deletion was associated with higher quantitative perception accuracy (96.9% vs 81.5%; p = 0.051). Tumor grade, recurrence, diagnosis, and isocitrate dehydrogenase-1 (IDH-1) status were not associated with accurate perception of EOR. Overall, new neurological deficits occurred in 8.4% of cases, and 42.1% of those new neurological deficits persisted after the 3-month follow-up. Correct quantitative perception was associated with lower postoperative motor deficits (2.4%) compared with incorrect perceptions (8.0%; p = 0.029). There were no detectable differences in language outcomes based on perception of EOR. CONCLUSIONS The findings from this study suggest that there is a learning curve associated with the ability to accurately assess intraoperative EOR during glioma surgery, and it may take more than a decade to be truly proficient. Understanding the factors associated with this ability to accurately assess EOR will provide safer surgeries while maximizing tumor resection.

Surgery guided by 5-aminolevulinic acid (ALA) fluorescence has become a valuable adjunct in the resection of malignant intracranial gliomas. Furthermore, the fluorescence intensity of biopsied areas of a resection cavity correlates with histological identification of tumor cells. However, in the case of lesions deep within a resection cavity, light penetration may be suboptimal, resulting in less excitation of 5-ALA metabolites, leading to decreased fluorescence emission. To address this obstacle, the authors report on the use of a 400-nm wavelength fiber-optic lighted suction instrument that can be used both during resection of a tumor and to provide direct light to deeper areas of a resection cavity. In the presented case, this wavelength-specific lighted suction instrument improved the fluorescence intensity of patches of malignant tissue within the resection cavity. This technique may further improve the utility of 5-ALA in identifying tumor-infiltrated tissue for deep-seated lesions. Additionally, this tool may have implications for scoring systems that correlate 5-ALA fluorescence intensity with histological identification of malignant cells.

OBJECTIVE Smoking is a known risk factor for aneurysm development and aneurysmal subarachnoid hemorrhage, as well as subsequent vasospasm in both untreated individuals and patients who have undergone surgical clipping of cerebrovascular aneurysms. However, there is a lack of data in the current scientific literature about the long-term effects that smoking has on the integrity of endovascular repairs of cerebral aneurysms. This study was designed to determine if any smoking history increased the risk of poorer outcomes and/or aneurysm recurrence in patients who have had endovascular repair of cerebral aneurysms. METHODS The authors retrospectively analyzed the medical records of patients admitted to the University of Michigan Health System from January 1999 to December 2011 with coiled aneurysms and angiography, CT angiography, or MR angiography follow-up. Patients were identified and organized based on many criteria including age, sex, smoking history, aneurysm recurrence, aneurysm location, and Hunt and Hess grade. Analysis was targeted to the patient population with a history of smoking. Bivariate chi-square tests were used to analyze the association between a positive smoking history and documented aneurysm recurrence and were adjusted for potential confounders by fitting multivariate logistic regression models of recurrence. RESULTS A total of 247 patients who had undergone endovascular treatment of 296 documented cerebral aneurysms were included in this study. The recurrence rate among all patients treated with endovascular repair was 24.3%, and the average time to the most recent follow-up imaging studies was 1.62 years. Smokers accounted for 232 aneurysms and were followed up for an average of 1.57 years, with a recurrence rate of 26.3%. Never smokers accounted for the remaining 64 aneurysms and were followed up for an average of 1.82 years, with a recurrence rate of 17.2%. Multivariate analysis revealed that, after controlling for potential confounders, a history of smoking-whether current or former-was associated with a significantly increased risk of aneurysm recurrence. The odds ratios for aneurysm recurrence for current and former smokers were 2.739 (95% CI 1.127-7.095, p = 0.0308) and 2.698 (95% CI 1.078-7.212, p = 0.0395), respectively, compared with never smokers. CONCLUSIONS A positive smoking history is associated with a significantly increased risk of aneurysm recurrence in patients who have undergone endovascular repair of a cerebral aneurysm, compared with the risk in patients who have never smoked.

OBJECTIVE Adult spinal deformity (ASD) develops in the setting of asymmetrical arthritic degeneration, and can also be due to iatrogenic causes, such as prior surgery. Many patients who present with ASD have undergone prior spine surgery with instrumentation. Unfortunately, contemporary studies that evaluate the effect of prior surgery or instrumentation on perioperative outcomes, readmission rates, and need for reoperation are lacking. METHODS All ASD patients who underwent a 3-column osteotomy performed by the senior author at the authors' institution for correction of thoracolumbar spinal deformity between 2006 and 2016 were identified. The authors compared surgical outcomes between primary (first-time) and revision cases. Further subgroup analysis was conducted to investigate the effect of the number of prior surgeries (0, 1, 2, 3, 4, and 5 or more) and the presence of spinal instrumentation on outcomes. Multivariate analysis was used to adjust for relevant and significant confounders. RESULTS A total of 300 patients were included; 38.3% of patients were male. The overall perioperative complication rate was 24.7%, and the mean length of hospitalization was 8.2 days. The 90-day readmission rate was 9.0%, and the overall follow-up reoperation rate was 26.7%. There were no significant differences in complication rates (26.6% vs 24.0%, p = 0.645), length of hospitalization (8.7 vs 7.9 days, p = 0.229), readmission rates (11.4% vs 8.1%, p = 0.387), or reoperation rates (26.6% vs 26.7%, p = 0.984) between primary and revision cases. There was no significant difference in wound complications (infections/dehiscence) requiring reoperation (5.1% vs 6.3%, p = 0.683). Subgroup analysis conducted to evaluate the effect of the number of prior spinal surgeries or the presence of spinal instrumentation did not reveal significant differences for the aforementioned surgical outcomes. In adjusted multivariate analysis, there were no significant associations between history of prior surgery (number of prior surgeries and prior instrumentation) and all of the surgical outcomes of interest. CONCLUSIONS The findings from this study suggest that patients who have undergone prior spine surgery with or without instrumentation are not at increased risk for perioperative complications, need for readmission, or reoperation following 3-column osteotomy of the thoracolumbar spine.