The role of Osteocel Plus as a fusion substrate in minimally invasive instrumented transforaminal lumbar interbody fusion.

BACKGROUND: Instrumented lumbar fusion has become an accepted and effective surgical technique used to address a wide variety of conditions of the lumbar spine. Iliac crest autograft remains the gold standard with regards to bony fusion substrate. Unfortunately there are significant potential disadvantages associated with autograft harvest, including pain, infection, iatrogenic fracture and bleeding. Osteocel Plus (OC+) is an allograft cellular bone matrix containing mesenchymal stem cells (MSCs) and osteoprogenitor cells combined with DBM and cancellous bone. OC+ is designed to mimic the osteobiologic profile of human autograft bone, thereby eliminating the risks of autograft harvest. METHODS: A retrospective chart review was conducted to identify all patients who had undergone a MITLIF with OC+ for degenerative lumbar conditions. Patient demographics including age, sex, history of risk factors for nonunion including: osteoporosis documented on DEXA scanning, diabetes mellitus, smoking or steroid use were examined and recorded. Successful arthrodesis was judged based on post-operative X-ray imaging. RESULTS: 23 patients at 26 spinal levels underwent a MITLIF with OC+. Twenty-one patients (91.3%) and 24 levels (92.3%) went on to achieve radiographic evidence of solid bony arthrodesis by 12 months post-op. Six patients (26%) demonstrated clear evidence of early interbody bone growth within 6 months of surgery. CONCLUSION: OC+ results in robust and reproducible lumbar interbody fusion, in both young and older patients.

Wrong-sided surgery.

OBJECT: Perhaps the single greatest error that a surgeon hopes to avoid is operating at the wrong site. In this report, the authors describe the incidence and possible determinants of incorrect-site surgery (ICSS) among neurosurgeons. METHODS: The authors asked neurosurgeons to complete an anonymous survey. These surgeons were asked to report the number of craniotomies and lumbar and cervical discectomies performed during the previous year, as well as whether ICSS had occurred. They were also asked detailed questions regarding the potential determinants of ICSS. RESULTS: There was a 75% response rate and a 68% survey completion rate. Participating neurosurgeons performed 4695 lumbar and 2649 cervical discectomies, as well as 10,203 craniotomies. Based on this self-reporting, the incidence of wrong-level lumbar surgery was estimated to be 4.5 occurrences per 10,000 operations. The ICSSs per 10,000 cervical discectomies and craniotomies were 6.8 and 2.2, respectively. Neurosurgeons recognized fatigue, unusual time pressure, and emergent operations as factors contributing to ICSS. For spine surgery, in particular, unusual patient anatomy and a failure to verify the operative site by radiography were also commonly reported contributors. CONCLUSIONS: Neurosurgical ICSSs do occur, but are rare events. Although there are significant limitations to the survey-based methodology, the data suggest that the prevention of such errors will require neurosurgeons to recognize risk factors and increase the use of intraoperative imaging.

A prospective evaluation of the role for intraoperative x-ray in lumbar discectomy. Predictors of incorrect level exposure.

BACKGROUND: Lumbar discectomy is among the most frequently performed procedures by spine surgeons. Among the potential difficulties encountered during this procedure, incorrect spinal level surgery remains a significant concern for surgeons and patients. Multiple groups have advocated the use of intraoperative x-ray to reduce the incidence of incorrect level surgery; however, this technique has not been prospectively evaluated. METHODS: In an effort to determine the incidence of incorrect level exposure during lumbar discectomy and to define patient characteristics predictive of wrong level exposure, we examined 100 consecutive patients who underwent lumbar discectomy by a single surgeon. After exposure, the surgeon was asked to identify the level exposed, which was confirmed by intraoperative x-ray. Several patient characteristics were then examined by logistical regression to identify features predictive of a mismatch between level of exposure and level of pathology. RESULTS: The study population was composed of 48 men and 52 women who were aged 18 to 83 years. Patient weights ranged from 105 to 410 lb. There were 51 patients who had pathology at the L5-S1 level; 44 patients, L4-L5; 3 patients, L3-L4; and 1 patient, L2-L3. Four patients had transitional vertebrae. The intended level was initially exposed in 85% of cases. Age and level of pathology (P < .05) were identified as factors predictive of a mismatch between intraoperative level of exposure and preoperative level of pathology. CONCLUSIONS: Pathology above L5-S1 and patient age have been shown to reliably predict incorrect level exposure. Based upon the findings of this study, the routine use of intraoperative x-ray to confirm the level of exposure should be considered in all cases of lumbar discectomy.

Functional outcomes and survival in patients with high-grade gliomas in dominant and nondominant hemispheres.

OBJECT: The goal of this study was to investigate survival and functional outcomes in patients with high-grade intracranial astrocytomas as a function of the location of the lesion in the dominant or nondominant hemisphere (DH and NDH, respectively), and to suggest management strategies for such patients based on these data. METHODS: Data were collected from the Glioma Outcomes Project database, a longitudinal database of demographic, clinical, and outcome data for patients with high-grade intracranial gliomas. From the entire database of 788 patients, a subset of all 280 right-handed patients with newly diagnosed, unilateral gliomas involving potentially eloquent cortex was selected as the sample population. Two cohorts were defined based on the location of the tumor in the right or left cerebral hemisphere. All other relevant demographic and clinical data were nearly identical between the cohorts. A Kaplan-Meier analysis was conducted to assess survival, and Karnofsky Performance Scale scores assigned at 6 and 12 months postoperatively were compared as a measure of functional outcome. The analysis demonstrated no difference in survival between patients with lesions in the DH and those with tumors in the NDH. Additionally, no statistically significant difference in functional outcomes was observed between the two groups. CONCLUSIONS: Laterality of high-grade gliomas is not an independent prognostic factor for predicting survival or functional outcome. The findings in this study demonstrate that fears of increased postoperative morbidity or mortality in otherwise resectable tumors of the DH are unfounded, and the authors therefore advocate that the surgeon's decision to operate be guided by validated outcome predictors and not biased by tumor lateralization.

Role of estrogen receptor-related antigen in initiating the growth of human glioma cells.

OBJECT: The expression of estrogen receptor-related antigen (ER-D5) has been demonstrated in many tumors, including those of the brain, but the actual role of ER-D5 in cell growth is unknown. The authors evaluated the role of ER-D5 in the growth of gliomas in vitro. METHODS: Human glioblastoma multiforme (GBM) cell lines A172, T98G, U87MG, and U118MG; rat C6 glioma and 9L gliosarcoma; AS human astrocytoma; GBM in primary culture and tumor tissues; and normal brain tissues were examined for ER-D5 by using immunohistochemical, Western immunoblot, flow cytometry, and enzyme-linked immunosorbent assays. The ER-D5 was detected in all tumor cell types of human origin, but not in rat cell lines and normal brain; the expression of ER-D5 was not related to cell cycle phase. Kinetic analysis of ER-D5 expression in cultured cell lines revealed that an enhanced and sharp accumulation of ER-D5 occurred during the first 24 hours of culture, followed by a sharp fall in the next 24 hours. Gradual decreases of ER-D5 during the subsequent days were demonstrated in all human cell lines, and in primary cultures of GBM. This accumulation pattern of ER-D5 was confirmed on Western blot analysis. The ER-D5 was also detected in cells cultured in serum-free medium. Culture cells were treated with D5 antibody against ER-D5 for 48 hours and the effects were evaluated using a monotetrazolium colorimetric assay; the result revealed that growth of cultured cells was inhibited in a dose-dependent manner, and that addition of a single median inhibitory concentration dose resulted in complete growth inhibition and arrest of cell growth at the G0/G1 phase at 96 hours posttreatment. CONCLUSIONS: These findings indicated that synthesis and accumulation of ER-D5 is an essential event in the very early phase of in vitro growth of human gliomas.