Does Obesity Affect Outcomes After Decompressive Surgery for Lumbar Spinal Stenosis? A Multicenter, Observational, Registry-Based Study.

OBJECTIVE: To evaluate the association between obesity and outcomes 1 year after laminectomy or microdecompression for lumbar spinal stenosis (LSS). METHODS: The primary outcome measure was the Oswestry Disability Index (ODI). Obesity was defined as body mass index (BMI) ≥ 30. Prospective data were retrieved from the Norwegian Registry for Spine Surgery. RESULTS: For all patients (n = 1473) the mean improvement in ODI at 1 year was 16.7 points (95% CI 15.7-17.7, P < 0.001). The improvement in ODI was 17.5 points in nonobese and 14.3 points in obese patients (P = 0 .007). Obese patients were less likely to achieve a minimal clinically important difference in ODI (defined as ≥ 8 points improvement) than nonobese patients (62.2 vs. 70.3%, P = 0.013). Obesity was identified as a negative predictor for ODI improvement in a multiple regression analysis (P < 0.001). Nonobese patients experienced more improvement in both back pain (0.7 points, P = 0.002) and leg pain (0.8 points, P = 0.001) measured by numeric rating scales. Duration of surgery was shorter for nonobese patients for both single- (79 vs. 89 minutes, P = 0.001) and 2-level (102 vs. 114 minutes, P = 0.004) surgery. There was no difference in complication rates (10.4% vs. 10.8%, P = 0.84). There was no difference in length of hospital stays for single- (2.7 vs. 3.0 days, P = 0.229) or 2-level (3.5 vs. 3.6 days, P = 0.704) surgery. CONCLUSIONS: Both nonobese and obese patients report considerable clinical improvement 1 year after surgery for LSS, but improvement was less in obese patients. Obese patients were less likely to achieve a minimal clinically important difference.

Does daily tobacco smoking affect outcomes after microdecompression for degenerative central lumbar spinal stenosis? - A multicenter observational registry-based study.

BACKGROUND: There are limited scientific data on the impact of smoking on patient-reported outcomes following minimally invasive spine surgery. The aim of this multicenter observational study was to examine the relationship between daily smoking and patient-reported outcome at 1 year using the Oswestry Disability Index (ODI) after microdecompression for single- and two-level central lumbar spinal stenosis (LSS). Secondary outcomes were the length of hospital stays, perioperative and postoperative complications. METHOD: Data were collected through the Norwegian Registry for Spine Surgery (NORspine). RESULTS: A total of 825 patients were included (619 nonsmokers and 206 smokers). For the whole patient population there was a significant difference between preoperative ODI and ODI at 1 year (17.3 points, 95% CI 15.93-18.67, p < 0.001). There was a significant difference in ODI change at 1 year between nonsmokers and smokers (4.2 points, 95% CI 0.98-7.34, p = 0.010). At 1 year 69.6% of nonsmokers had achieved a minimal clinically important difference (≥10 points ODI improvement) compared to 60.8% of smokers (p = 0.008). There was no difference between nonsmokers and smokers in the overall complication rate (11.6% vs. 9.2%, p = 0.34). There was no difference between nonsmokers and smokers in length of hospital stays for either single-level (2.3 vs. 2.2 days, p = 0.99) or two-level (3.1 vs. 2.3 days, p = 0.175) microdecompression. Smoking was identified as a negative predictor for ODI change in a multiple regression analysis (p = 0.001) CONCLUSIONS: Nonsmokers experienced a significantly larger improvement at 1 year following microdecompression for LSS compared to smokers. Smokers were less likely to achieve a minimal clinically important difference. However, it should be emphasized that considerable improvement also was found among smokers.

Metabolic profiles of brain metastases.

Metastasis to the brain is a feared complication of systemic cancer, associated with significant morbidity and poor prognosis. A better understanding of the tumor metabolism might help us meet the challenges in controlling brain metastases. The study aims to characterize the metabolic profile of brain metastases of different origin using high resolution magic angle spinning (HR-MAS) magnetic resonance spectroscopy (MRS) to correlate the metabolic profiles to clinical and pathological information. Biopsy samples of human brain metastases (n = 49) were investigated. A significant correlation between lipid signals and necrosis in brain metastases was observed (p < 0.01), irrespective of their primary origin. The principal component analysis (PCA) showed that brain metastases from malignant melanomas cluster together, while lung carcinomas were metabolically heterogeneous and overlap with other subtypes. Metastatic melanomas have higher amounts of glycerophosphocholine than other brain metastases. A significant correlation between microscopically visible lipid droplets estimated by Nile Red staining and MR visible lipid signals was observed in metastatic lung carcinomas (p = 0.01), indicating that the proton MR visible lipid signals arise from cytoplasmic lipid droplets. MRS-based metabolomic profiling is a useful tool for exploring the metabolic profiles of metastatic brain tumors.

Differentiating diffuse World Health Organization grade II and IV astrocytomas with ex vivo magnetic resonance spectroscopy.

BACKGROUND: The prognosis and treatment of astrocytomas, which are primary brain tumors, vary depending on the grade of the tumor, necessitating a precise preoperative classification. Magnetic resonance spectroscopy (MRS) provides information about metabolites in tissues and is an emerging noninvasive tool to improve diagnostic accuracy in patients with intracranial neoplasia. OBJECTIVE: To investigate whether ex vivo MRS could differentiate World Health Organization grade II (A-II) and IV astrocytomas (glioblastomas; GBM) and to correlate MR spectral profiles with clinical parameters. METHODS: Patients with A-II and GBM (n = 58) scheduled for surgical resection were enrolled. Tumor specimens were collected during surgery and stored in liquid nitrogen before being analyzed with high-resolution magic angle spinning MRS. The tumors were histopathologically classified according to World Health Organization criteria as GBM (n = 48) and A-II (n = 10). RESULTS: Multivariate analysis of ex vivo proton high-resolution magic angle spinning spectra MRS showed differences in the metabolic profiles of different grades of astrocytomas. A-II had higher levels of glycerophosphocholine and myo-inositol than GBM. The latter had more phosphocholine, glycine, and lipids. We observed a significant metabolic difference between recurrent and nonrecurrent GBM (P < .001). Primary GBM had more phosphocholine than recurrent GBM. A significant correlation (P < .001) between lipid and lactate signals and histologically estimated percentage of necrosis was observed in GBM. Spectral profiles were not correlated with age, survival, or magnetic resonance imaging-defined tumor volume. CONCLUSION: Ex vivo MRS can differentiate astrocytomas based on their metabolic profiles.

The influence of surgery on quality of life in patients with intracranial meningiomas: a prospective study.

Meningiomas may influence both survival and neurological functions. Studies assessing the impact of surgery on health-related quality of life (HRQL) remain absent. In this prospective study we aimed to describe HRQL dynamics before and after surgery in patients with meningiomas. HRQL assessments were performed using EuroQol-5D (EQ-5D), a generic HRQL instrument. All adult patients with suspected intracranial meningioma from 2007 through 2011 were eligible for inclusion, and 54 patients were included after informed consent. All patients received a histopathological diagnosis of meningioma. The average preoperative EQ-5D index value (±SD) was 0.69 ± 0.26. The mean improvement 6 weeks after surgery was 0.06 (95 % CI, -0.03 to 0.16; p = 0.161) and the mean long term improvement was 0.09 (95 % CI, 0.00-0.17; p = 0.040). Surgery reduced pain/discomfort and anxiety/depression and improved the capability of performing usual activities. Clinically significant improvement at long-term assessment was noted in 25 patients (49 %) while a significant deterioration was reported in 10 patients (20 %). Patients who reported postoperative worsening of HRQL were also reporting better preoperative scores, suggesting a possible ceiling effect of EQ-5D in some of these patients. In our patients a modest average improvement in HRQL was seen after surgery for meningioma. About half of the patients reported a clinical important improvement at the late follow-up assessment. This improvement was mainly observed in the domains usual activities, pain/discomfort and anxiety/depression. However, one in five patients fared worse on late follow-up assessment, a figure of particular importance when treating asymptomatic meningiomas.

Overexpression of c-erbB2 is a negative prognostic factor in anaplastic astrocytomas.

The epidermal growth factor receptor (EGFR) family, consisting of four tyrosine kinase receptors, c-erbB1-4, seems to be influential in gliomagenesis. The aim of this study was to investigate EGFR gene amplification and expression of c-erbB1-4 receptor proteins in human anaplastic astrocytomas. Formalin-fixed and paraffin-embedded sections from 31 cases were investigated by standard immunohistochemical procedures for expression of c-erbB1-4 receptor proteins using commercial antibodies. EGFR gene amplification was studied by fluorescence in situ hybridization using paraffin-embedded tissues. Two monoclonal antibodies, NCL-EGFR-384 and NCL-EGFR, were used for EGFR detection and they displayed positive immunoreactivity in 97% and 71%, respectively. For c-erbB2 detection three monoclonal antibodies, CB11, 3B5, and 5A2, were applied and they displayed positive immunoreactivity in 45%, 100%, and 52%, respectively. Positive immunostaining for c-erbB3 and c-erbB4 was encountered in 97% and 74%, respectively. The EGFR gene was amplified in 9 out of 31 tumors (29%). After adjusting for age, Karnofsky performance status, and extent of surgical resection, Cox multiple regression analysis with overall survival as the dependent variable revealed that c-erbB2 overexpression detected by the monoclonal antibody clone CB11 was a statistically significant poor prognostic factor (P = 0.004). This study shows the convenience and feasibility of immunohistochemistry when determining the expression of receptor proteins in tissue sections of human astrocytomas. The synchronous overexpression of c-erbB1-4 proteins in anaplastic astrocytomas supports their role in the pathogenesis of these tumors. Further, c-erbB2 overexpression seems to predict aggressive behaviour.