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Fangyou Gao, Qu Wang, Chuangxi Liu, Bing Xiong and Tao Luo

OBJECTIVE

This study was undertaken to evaluate the feasibility and efficacy of individualized 3D printed model–assisted posterior internal fixation in treating craniovertebral junction (CVJ) abnormalities.

METHODS

Forty-four patients (19 males and 25 females; mean age 36.5 ± 9.2 years, range 11–62 years; symptom duration 1 month–15 years) with a CVJ abnormality who were admitted to the authors’ institution between April 2010 and April 2015 were retrospectively studied. The individualized 3D printed model of the CVJ was produced based on the individual CT data by use of 3D printing technology. The posterior internal fixation was simulated on the model to obtain data for individual patients, which were then used for intraoperative assistance. One-stage posterior decompression combined with internal fixation was performed. The results were evaluated using the Japanese Orthopaedic Association (JOA) scale, atlanto-dens interval (ADI), and cervicomedullary angle (CMA). The patients underwent follow-up and outcomes were evaluated using CT, MRI, and the JOA scale score. The comparison between preoperative and postoperative JOA scale scores was done using a paired t-test.

RESULTS

Thirty-eight individualized 3D printed models were successfully built. The 38 patients underwent successful posterior internal fixation performed with the assistance of 3D printed models. In the 6 patients without an individualized printed model (i.e., the patients who underwent surgery before 3D printed modeling was available at the authors’ institution), the pedicle screw was inserted incorrectly into the transverse foramen in 2 patients and inserted incorrectly into the vertebral canal in 1 patient. All patients were observed for a mean of 26 months (range 3–52 months). The postoperative JOA scale scores for all patients significantly improved from the preoperative scores. Among the 41 patients treated with atlantoaxial distraction reduction, postoperative MRI and CT showed complete reduction in 31 patients and incomplete reduction in 10 patients (reduction rate > 50%). The postoperative ADI significantly decreased, and the CMA significantly increased.

CONCLUSIONS

Individualized 3D printed model–assisted posterior internal fixation seems feasible and effective in optimizing the treatment of CVJ abnormalities. In addition, it offers many advantages, including preoperative simulation, intraoperatve guidance, and intraoperative error minimization.

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Song-tao Qi, Yi Liu, Jun Pan, Silky Chotai and Lu-xiong Fang

Object

The completeness of meningioma resection depends on the resection of dura mater invaded by the tumor. The pathological changes of the dura around the tumor can be interpreted by evaluating the dural tail sign (DTS) on MRI studies. The goal of this study was to clarify the pathological characteristics of the DTSs, propose a classification based on the histopathological and radiological correlation, and identify the invasive range of tumor cells in different types of DTS.

Methods

The authors retrospectively reviewed 179 patients with convexity meningiomas who underwent Simpson Grade I resection. All patients underwent an enhanced MRI examination preoperatively. The convexity meningiomas were dichotomized into various subtypes in accordance with the 2007 WHO classification of tumors of the CNS, and the DTS was identified based on the Goldsher criteria. The range of resection of the involved dura was 3 cm from the base of the tumor, which corresponded with the length of DTS on MRI studies. Histopathological examination of dura at 0.5, 1.0, 1.5, 2.0, 2.5, and 3.0 cm from the base of the tumor was conducted, and the findings were correlated with the preoperative MRI appearance of the DTS.

Results

A total of 154 (86%) of 179 convexity meningiomas were classified into WHO Grade I subtype, including transitional (44 [28.6%] of 154), meningothelial (36 [23.4%] of 154), fibrous (23 [14.9%] of 154), psammomatous (22 [14.3%] of 154), secretory (10 [6.5%] of 154), and angiomatous (19 [12.3%] of 154). The other 25 (14%) were non–Grade I (WHO) tumors, including atypical (12 [48%] of 25), anaplastic (5 [20%] of 25), and papillary (8 [32%] of 25). The DTS was classified into 5 types: smooth (16 [8.9%] of 179), nodular (36 [20.1%] of 179), mixed (57 [31.8%] of 179), symmetrical multipolar (15 [8.4%] of 179), and asymmetrical multipolar (55 [30.7%] of 179). There was a significant difference in distribution of DTS type between Grade I and non–Grade I tumors (p = 0.004), whereas the difference was not significant among Grade I tumors (0.841) or among non–Grade I tumors (p = 0.818). All smooth-type DTSs were encountered in Grade I tumors, and the mixed DTS (52 [33.8%] of 154) was the most common type in these tumors. Nodular-type DTS was more commonly seen in non–Grade I tumors (12 [48%] of 25). Tumor invasion was found in 88.3% (158 of 179) of convexity meningiomas, of which the range of invasion in 82.3% (130 of 158) was within 2 cm and that in 94.9% (150 of 158) was within 2.5 cm. The incidence of invasion and the range invaded by tumor cells varied in different types of DTS, and differences were statistically significant (p < 0.001).

Conclusions

Nodular-type DTS on MRI studies might be associated with non–Grade I tumors. The range of dural resection for convexity meningiomas should be 2.5 cm from the tumor base, and if this extent of resection is not feasible, the type of DTS should be considered. However, for skull base meningiomas, in which mostly Simpson Grade II resection is achieved, the use of this classification should be further validated. The classification of DTS enables the surgeon to predict preoperatively and then to achieve the optimal range of dural resection that might significantly reduce the recurrence rate of meningiomas.

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Feng Wang, Tao Sun, Xing-Gang Li and Na-Jia Liu

Object

The aim of this study was to use diffusion tensor tractography (DTT) to define the 3D relationships of the uncinate fasciculus, anterior commissure, inferior occipitofrontal fasciculus, inferior thalamic peduncle, and optic radiation and to determine the positioning landmarks of these white matter tracts.

Methods

The anatomy was studied in 10 adult human brain specimens. Brain DTT was performed in 10 healthy volunteers. Diffusion tensor tractography images of the white matter tracts in the temporal stem were obtained using the simple single region of interest (ROI) and multi-ROIs based on the anatomical knowledge.

Results

The posteroinferior insular point is the anterior extremity of intersection of the Heschl gyrus and the inferior limiting sulcus. On the inferior limiting sulcus, this point is the posterior limit of the optic radiation, and the temporal stem begins at the limen insulae and ends at the posteroinferior insular point. The distance from the limen insulae to the tip of the temporal horn is just one third the length of the temporal stem. The uncinate fasciculus comprises the core of the anterior temporal stem, behind which the anterior commissure and the inferior thalamic peduncle are located, and they occupy the anterior third of the temporal stem. The inferior occipitofrontal fasciculus passes through the entire temporal stem. The most anterior extent of the Meyer loop is located between the anterior tip of the temporal horn and the limen insulae. Most of the optic radiation crosses the postmedian two thirds of the temporal stem.

Conclusions

On the inferior limiting sulcus, the posteroinferior insular point is a reliable landmark of the posterior limit of the optic radiations. The limen insulae, anterior tip of the temporal horn, and posteroinferior insular point may be used to localize the white matter fibers of the temporal stem in analyzing magnetic resonance imaging or during surgery.

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Lei Liu, Tao Sui, Xin Hong, Xiaotao Wu and Xiaojian Cao

Object

The authors conducted a study to evaluate the effects and the safety of locally applied mitomycin C (MMC) on epidural fibrosis after microendoscopic discectomy (MED).

Methods

Seventy-five patients undergoing single-level unilateral MED for lumbar disc herniation were randomly assigned to receive cotton wool impregnated with either 0.5 mg/ml MMC or saline applied at the site of discectomy for 5 minutes. Outcome measures included degrees of pain severity, functional disability, physical symptoms, and quantitative evaluation of postoperative epidural fibrosis shown on follow-up lumbar contrast-enhanced MRI.

Results

Sixty-two patients completed the follow-up. Neither serious drug adverse effects nor clinically significant laboratory adverse effects were observed. Patients in both groups showed similar clinical recoveries postoperatively. A statistically significant difference (p < 0.05) between the 2 treatments was shown in a quantitative evaluation of postoperative MRI-documented epidural fibrosis in the MMC group and the saline group using a modified grading system. The mean cross-sectional areas of epidural fibrosis were 7.32–70.06 mm2 in the MMC group and 22.94–90.48 mm2 in the saline group. The epidural fibrosis index ranged from 0.0296 to 0.3267 in the MMC group and from 0.1191 to 0.3483 in the saline group. A significant difference was also observed using the Ross grading system to evaluate postoperative MR images.

Conclusions

Although no benefit was observed clinically, the authors observed a notable reduction of epidural fibrosis after MED radiologically, with 0.5 mg/ml MMC locally applied and no clinical side effects. Clinical trial registration no.: ChiCTR-TRC-10001079 (http://www.chictr.org/cn/proj/show.aspx?proj=326).

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Wen-Chao Liu, Liang Wen, Tao Xie, Hao Wang, Jiang-Biao Gong and Xiao-Feng Yang

OBJECTIVE

Erythropoietin (EPO) exerts a neuroprotective effect in animal models of traumatic brain injury (TBI). However, its effectiveness in human patients with TBI is unclear. In this study, the authors conducted the first meta-analysis to assess the effectiveness and safety of EPO in patients with TBI.

METHODS

In December 2015, a systematic search was performed of PubMed, Web of Science, MEDLINE, Embase, the Cochrane Library databases, and Google Scholar. Only English-language publications of randomized controlled trials (RCTs) using EPO in patients with TBI were selected for analysis. The assessed outcomes included mortality, favorable neurological outcome, hospital stay, and associated adverse effects. Continuous variables were presented as mean difference (MD) with a 95% confidence interval (CI). Dichotomous variables were presented as risk ratio (RR) or risk difference (RD) with a 95% CI. Statistical heterogeneity was examined using both I2 and chi-square tests.

RESULTS

Of the 346 studies identified in the search, 5 RCTs involving 915 patients met the inclusion criteria. The overall results demonstrated that EPO significantly reduced mortality (RR 0.69, 95% CI 0.49–0.96, p = 0.03) and shortened the hospitalization time (MD −7.59, 95% CI −9.71 to −5.46, p < 0.0001) for patients with TBI. Pooled results of favorable outcome (RR 1.00, 95% CI 0.88–1.15, p = 0.97) and deep vein thrombosis (DVT; RD 0.00, 95% CI −0.05 to 0.05, p = 1.00) did not show a significant difference.

CONCLUSIONS

The authors suggested that EPO is beneficial for patients with TBI in terms of reducing mortality and shortening hospitalization time without increasing the risk of DVT. However, its effect on improving favorable neurological outcomes did not reach statistical significance. Therefore, more well-designed RCTs are necessary to ascertain the optimum dosage and time window of EPO treatment for patients with TBI.

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Xiaolei Hao, Ruie Feng, Yalan Bi, Yuhan Liu, Chunde Li, Tao Lu and Yongji Tian

Erdheim-Chester disease (ECD) is a rare non–Langerhans cell form of histiocytosis that can affect the central nervous system. ECD predominantly affects adults, and only a few pediatric cases have been reported. The co-occurrence of ECD and Langerhans cell histiocytosis (LCH) is exceedingly rare. An 11-year-old boy, who was diagnosed with LCH 7 years previously, presented with multiple giant intracranial lesions. At the time of his initial diagnosis, only one intracranial lesion was observed, and it began to enlarge. Currently, up to 7 intracranial lesions can be observed in this patient. However, the diagnosis of ECD was not confirmed until this most recent open resection. The BRAF V600E mutation was detected in both LCH and ECD lesions. Dabrafenib therapy exhibited dramatic efficacy in this pediatric patient. This case represents the first successful application of dabrafenib in a pediatric patient with intracranial ECD lesions as well as mixed ECD and LCH. In this article, the authors describe the intricate diagnosis and treatment processes in this patient. Recent studies regarding treatment with BRAF inhibitors for neurological involvement in mixed ECD and LCH are also reviewed.

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Chao-hu Wang, Song-Tao Qi, Jun Fan, Jun Pan, Jun-Xiang Peng, Jing Nie, Yun Bao, Ya-Wei Liu, Xi’an Zhang and Yi Liu

OBJECTIVE

Nuclear β-catenin, a hallmark of active canonical Wnt signaling, can be histologically detected in a subset of cells and cell clusters in up to 94% of adamantinomatous craniopharyngioma (ACP) samples. However, it is unclear whether nuclear β-catenin–containing cells within human ACPs possess the characteristics of tumor stem cells, and it is unknown what role these cells have in ACP.

METHODS

Primary ACP cells were cultured from 12 human ACP samples. Adamantinomatous CP stem cell–like cells (CSLCs) showing CD44 positivity were isolated from the cultured primary ACP cells by performing magnetic-activated cell sorting. The tumor sphere formation, cell cycle distribution, stemness marker expression, and multidifferentiation potential of the CD44− cells and the CSLCs were analyzed.

RESULTS

Compared with the CD44− cells, the cultured human CSLCs formed tumor spheres and expressed CD44 and CD133; moreover, these cells demonstrated nuclear translocation of β-catenin. In addition, the CSLCs demonstrated osteogenic and adipogenic differentiation capacities compared with the CD44− cells. The CSLCs also displayed the capacity for tumor initiation in human–mouse xenografts.

CONCLUSIONS

These results indicate that CSLCs play an important role in ACP development, calcification, and cystic degeneration.

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Mijin Kim and Chang-Hyun Lee

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Jingming Xie, Yingsong Wang, Zhi Zhao, Ying Zhang, Yongyu Si, Tao Li, Zhendong Yang and Luping Liu

Object

The surgical treatment of severe and rigid spinal deformities poses difficulties and dangers. In this article, the authors summarize their surgical techniques and evaluate patient outcomes after performing posterior vertebral column resection (PVCR) for the correction of spinal deformities with curves greater than 100°, and investigate the crucial points to ensure neurological safety during this challenging procedure.

Methods

The authors retrospectively reviewed their experience with 28 patients with extremely severe (Cobb angles in the coronal or sagittal plane > 100°) and rigid thoracic or thoracolumbar spine deformities who underwent PVCR. The average patient age was 20.2 years and all patients underwent a minimum follow-up of 24 months (range 24–60 months). Patients were divided into groups according to their morphological classification as follows: kyphosis alone (Group A, 6 patients with a mean Cobb angle of 109.0° [range 105°–120°]); kyphoscoliosis with coronal plane curves notably greater than sagittal plane curves (Group B, 14 patients with mean scoliotic curves of 116.6° [range 102°–170°] and kyphotic curves of 77.7° [range 42°–160°]); and kyphoscoliosis with sagittal curves notably greater than coronal plane curves (Group C, 8 patients with a mean coronal curve of 85.4° [range 65°–110°] and a mean sagittal curve of 117.6° [range 102°–155°]).

Results

A total of 36 vertebrae were removed in 28 patients who had a severe rigid spinal deformity, and the mean fusion extent was 13.3 vertebrae (range 7–17 vertebrae). The mean operating time was 620 minutes (range 320–920 minutes) with an average operative blood loss of 6,680 ml (range 3,000–24,000 ml). The overall final correction rate of scoliosis was 59.0%, and average postoperative kyphotic Cobb angles ranged from 30.4° to 95.9°. In Group A the mean preoperative sagittal angle of 109.0° was corrected to a mean postoperative angle of 32.0°. In the Group B kyphoscoliotic patients, the correction rate in the coronal plane was 58.6%; the Cobb angle in the sagittal plane was corrected from a mean of 77.7° preoperatively to 25.1° postoperatively; in Group C, the correction rate in the coronal plane was 58.5%, and the mean sagittal angle was reduced from a mean of 117.6° preoperatively to 39.0°. Of the 28 patients who underwent PVCR, 46 complications were observed in 18 patients intra- and postoperatively. There were 5 neurological complications including 1 case of late-onset paralysis and 4 cases of thoracic nerve root pain, all of which resolved during the early follow-up period. Nonneurological complications occurred more often in kyphoscoliotic patients (41 complications). The mean follow-up of all patients was 33.7 months (range 24–60 months).

Conclusions

Posterior vertebral column resection was effective in correcting severe rigid spinal deformity, although the procedure was technically demanding, exhaustingly lengthy, and was associated with a variety of complications. The PVCR technique created a space for spinal correction and spinal cord tension adjustment and the correction could be performed under direct inspection and by palpation of the tension in the spinal cord through the space. Therefore, in terms of the spinal cord, the deformity correction process involved in the PVCR procedure is relatively safe.