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Hua Liu, Zhongkun Liu, Yong Liu, Shifeng Kan, Jian Yang, and Hongyi Liu

OBJECTIVE

Chronic subdural hematoma (CSDH) is prevalent in the aged population and is commonly treated with bur hole drainage. This treatment, however, can lead to various surgical complications. Atorvastatin may cure CSDH via its antiinflammatory and proangiogenesis effects, but not all patients treated with this medication can avoid surgery. The authors' aim was to investigate the effect of atorvastatin and identify characteristics of patients with CSDH sensitive to atorvastatin therapy.

METHODS

A prospective, placebo-controlled observational study was conducted in 80 patients with evidence of CSDH. The patients were enrolled between February 2012 and August 2014 and were randomly assigned to either atorvastatin treatment (atorvastatin group) or placebo (control group). Patients were followed up for 12 months after initiation of treatment. Clinically relevant data were collected and compared between the 2 groups. The atorvastatin group was subdivided into patients who required surgery and those who did not, and characteristics of these subgroups were also compared. The relationship between atorvastatin treatment and need for surgery was investigated by means of multiple regression analysis using the following variables as predictors: age, sex, admission Markwalder grade, level of dependency in activities of daily living (ADL) as assessed with the modified Barthel Index, presence of hemiparesis, and hematoma volume.

RESULTS

The proportion of patients who required surgical intervention during the follow-up period was significantly lower in the atorvastatin group than in the control group (p = 0.001), and the mean time to surgery was longer in the atorvastatin group (p = 0.018). Within the atorvastatin group, there was a significant difference with respect to Markwalder grades, degree of dependency in ADL, percentage of patients with hemiparesis, and mean hematoma volume between the patients who required surgery during the follow-up period and those who did not (p = 0.002, p = 0.001, p = 0.001, and p = 0.012, respectively). The results of the logistic regression analysis showed that atorvastatin significantly reduced the probability of surgery and that female sex and favorable admission Markwalder grades and favorable dependency status with respect to ADL (independent, slightly dependent, or moderately dependent) were independent predictors of not requiring surgery.

CONCLUSIONS

Atorvastatin administration can promote the resolution of CSDH, especially for women with favorable Markwalder grades and favorable ADL dependency status at admission.

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Yang Liu, Ka-Yun Ng, and Kevin O. Lillehei

Object

There have been numerous attempts to establish an effective immunotherapy for the treatment of brain tumors. To date, reliable methods to manipulate the immune system for promoting brain tumor regression have been disappointing. Generation of active immune responses in most of these studies was only possible in the absence of viable tumor cells, suggesting that immunotherapy can only be used as preventive therapy. In few studies the investigators have demonstrated success in using immunotherapy to treat a preestablished intracranial tumor. Using the 9L intracranial glioma model, the authors sought to delineate the underlying mechanisms for these observations.

Methods

In animals vaccinated with irradiated 9L glioma cells and interferon-gamma 14 and 7 days prior to intracranial tumor cell challenge, a significant increase in survival was shown. In contrast, vaccinations applied 3 days prior to, at the time of (Day 0) or 7 days after intracranial tumor cell challenge failed to influence survival. Histological examination of brain tissue specimens obtained in animals vaccinated before or after tumor cell challenge showed no difference in the degree of peritumoral mononuclear cell infiltration. When activated spleen cells obtained obtained from these animals were assayed for cytotoxicity and proliferative capacity, only those spleen cells derived from animals vaccinated prior to intracranial tumor cell challenge showed enhanced activity.

Conclusions

These data support the presence of a strong modulatory effect of tumor on local and systemic antitu-moral immune response. This immunosuppression appears to be secondary to a direct effect on T-cell function. Reversal of this immunosuppression may be a useful adjunct to tumor vaccine therapy.

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Yang Li, Xinxin Yuan, Shifu Sha, Zhen Liu, Weiguo Zhu, Yong Qiu, Bin Wang, Yang Yu, and Zezhang Zhu

OBJECTIVE

The aim of this study was to investigate how implant density affects radiographic results and clinical outcomes in patients with dystrophic scoliosis secondary to neurofibromatosis Type 1 (NF1).

METHODS

A total of 41 patients with dystrophic scoliosis secondary to NF1 who underwent 1-stage posterior correction between June 2011 and December 2013 were included. General information about patients was recorded, as were preoperative and postoperative scores from Scoliosis Research Society (SRS)–22 questionnaires. Pearson correlation analysis was used to analyze the associations among implant density, coronal Cobb angle correction rate and correction loss at last follow-up, change of sagittal curve, and apical vertebral translation. Patients were then divided into 2 groups: those with low-density and those with high-density implants. Independent-sample t-tests were used to compare demographic data, radiographic findings, and clinical outcomes before surgery and at last follow-up between the groups.

RESULTS

Significant correlations were found between the implant density and the coronal correction rate of the main curve (r = 0.505, p < 0.01) and the coronal correction loss at final follow-up (r = −0.379, p = 0.015). There was no significant correlation between implant density and change of sagittal profile (p = 0.662) or apical vertebral translation (p = 0.062). The SRS-22 scores improved in the appearance, activity, and mental health domains within both groups, but there was no difference between the groups in any of the SRS-22 domains at final follow-up (p > 0.05 for all).

CONCLUSIONS

Although no significant differences between the high- and low-density groups were found in any of the SRS-22 domains at final follow-up, higher implant density was correlated with superior coronal correction and less postoperative correction loss in patients with dystrophic NF1-associated scoliosis.

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Benlong Shi, Dun Liu, Zezhang Zhu, Yu Wang, Yang Li, Zhen Liu, Xu Sun, and Yong Qiu

OBJECTIVE

The aim of this study was to compare the radiographic and clinical outcomes in patients with degenerative scoliosis (DS) with type C coronal imbalance who underwent either a sequential correction technique or a traditional 2-rod technique with a minimum of 2 years of follow-up.

METHODS

DS patients with type C coronal imbalance undergoing posterior correction surgery from February 2014 to January 2018 were divided into groups by technique: the sequential correction technique (SC group) and the traditional 2-rod technique (TT group). Radiographic parameters, including Cobb angle, coronal balance distance (CBD), global kyphosis (GK), thoracic kyphosis (TK), lumbar lordosis (LL), sagittal vertical axis (SVA), pelvic incidence (PI), pelvic tilt (PT), and sacral slope, were assessed pre- and postoperatively. The SF-36 questionnaire was used to assess quality of life.

RESULTS

A total of 34 patients were included. Significant postoperative improvement in the Cobb angle of the main curve, CBD, GK, TK, LL, SVA, and PT was found in both groups (p < 0.05). Postoperatively, the coronal balance was type A in 13 patients (92.9%) in the SC group and in 16 patients (80.0%) in the TT group (p = 0.298). In the TT group, 1 patient had deteriorative coronal imbalance immediately postoperatively, and coronal imbalance deteriorated from type A to type C in 2 patients during follow-up. The scores of Physical Functioning, Role-Physical, Bodily Pain, Vitality, Social Functioning, Role-Emotional, and Mental Health were statistically improved postoperatively (p < 0.05) in both groups. Type C coronal imbalance at the last follow-up was associated with a relatively worse quality of life. There were no implant failures during follow-up in the SC group, whereas rod fracture was observed in 3 patients in the TT group.

CONCLUSIONS

Compared with the traditional 2-rod technique, the sequential correction technique can simplify rod installation procedure, enhance internal instrumentation, and reduce risk of implant failures. The sequential correction technique could be routinely recommended for DS patients with type C coronal imbalance.

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Haichun Liu, Wenliang Wu, Yi Li, Jinwei Liu, Kaiyun Yang, and Yunzhen Chen

Object

During the past decades, lumbar fusion has increasingly become a standard treatment for degenerative spinal disorders. However, it has also been associated with an increased incidence of adjacent-segment degeneration (ASD). Previous studies have reported less ASD in anterior fusion surgeries; thus, the authors hypothesized that the integrity of the posterior complex plays an important role in ASD. This study was designed to investigate the effect of the posterior complex on adjacent instability after lumbar instrumentation and the development of ASD.

Methods

To evaluate different surgical interventions, 120 patients were randomly allocated into 3 groups of 40 patients each who were statistically similar with respect to demographic and clinical data. Patients in Group A were allocated for facet joint resection and L4–5 fusion, Group B for semilaminectomy and fusion, and Group C for complete laminectomy and fusion. All of the patients were followed up for 5–7 years (mean 5.9 years). The disc height, intervertebral disc angle, dynamic intervertebral angular range of motion (ROM), L3–4 slip, and the total lordosis angle were each measured before the operation and at the final follow-up. The Japanese Orthopaedic Association (JOA) score was determined before surgery and at the final follow-up to evaluate the clinical results.

Results

Among the 3 groups, no significant differences were detected in all clinical and demographic assessments before surgery. At 3 months after surgery, the JOA score of all groups improved significantly and showed no significant differences among the groups. At the final follow-up, Group C had a significantly (p < 0.05) lower JOA score than the other 2 groups. Moreover, the disc height and total lumbar lordosis in patients of Group C were significantly decreased compared with disc height and total lumbar lordosis in the other 2 groups. In contrast, disc angle, dynamic angular ROM, and listhesis were significantly higher in Group C than in the other 2 groups. Twenty-four patients showed signs of ASD after the operation (3 patients in Group A, 4 in B, and 17 in C). The number of patients in Group C showing ASD was significantly different from that in Groups A and B.

Conclusions

During follow-up for 6 years, a significantly higher number of patients with ASD were noted in the complete-laminectomy group. The number of reoperations for treating ASD was much higher in this patient group than in the patients undergoing facet joint resection and L4–5 fusion or semilaminectomy and fusion. Therefore, preserving the posterior complex as much as possible during surgery plays an important role in preventing ASD and in reducing the reoperation rate.

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Hongru Ma, Benlong Shi, Yang Li, Dun Liu, Zhen Liu, Xu Sun, Yong Qiu, and Zezhang Zhu

OBJECTIVE

The aim of this study was to compare the radiological and clinical outcomes of early-onset scoliosis (EOS) patients with or without intraspinal anomalies (IAs) managed with growing rods (GRs), and to evaluate the safety of the GR technique in EOS patients with untreated IAs.

METHODS

EOS patients undergoing GR placement between August 2008 and July 2017 were retrospectively reviewed. Patients with untreated IAs were classified into the EOS+IA group, and those without IAs into the EOS−IA group. The radiographic parameters including Cobb angle of the major curve, T1–S1 height, and apical vertebral translation were measured, and a detailed assessment of the neurological status was performed at each visit.

RESULTS

Seventy-six patients with EOS (32 boys, 44 girls) with an average age of 6.5 ± 2.3 years at initial surgery satisfied the inclusion and exclusion criteria, including 28 patients in the EOS+IA group and 48 patients in the EOS−IA group. The radiographic measurements were comparable between groups preoperatively, postoperatively, and at the latest follow-up. One patient in the EOS+IA group experienced sensory deficit in a unilateral lower extremity after initial surgery, and an intraoperative neurophysiological monitoring event was observed in a patient in the EOS−IA group. No permanent neurological deficit was observed in either group.

CONCLUSIONS

EOS patients with and those without IAs had comparable clinical and radiological outcomes of the GR technique. Repeated lengthening procedures may be safe for EOS patients with untreated IAs.

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Yang Li, Benlong Shi, Dun Liu, Zhen Liu, Xu Sun, Yong Qiu, and Zezhang Zhu

OBJECTIVE

The aim of this paper was to compare the radiographic and clinical outcomes between the sequential correction (SC) technique and the traditional 2-rod correction (TC) technique in patients with severe thoracic idiopathic scoliosis (STIS) undergoing posterior-only correction surgery.

METHODS

Records of a consecutive series of STIS patients undergoing posterior-only correction surgery between October 2013 and October 2017 with more than 2 years of follow-up were reviewed. The radiographic parameters were assessed preoperatively, postoperatively, and at the last follow-up. Radiographic parameters, operative time, blood loss, and complications were compared between the two groups.

RESULTS

A total of 33 patients were included in the SC group, and 21 patients were included in the TC group. There was no significant difference in age, sex, or deformity magnitude (93.6° ± 7.8° vs 89.8° ± 6.6°, p = 0.070) preoperatively between groups. The operation time was shorter in the SC group than in the TC group (251.5 ± 42.8 minutes vs 275.4 ± 39.8 minutes, p = 0.020), while both blood loss (1284.6 ± 483.3 vs 1398.0 ± 558.4 ml, p = 0.432) and number of fused levels (13.1 ± 2.8 vs 13.6 ± 2.4, p = 0.503) were similar between the groups. Compared with the TC group, patients in the SC group had a higher correction rate (55.8% ± 9.2% vs 45.7% ± 8.8%, p < 0.001), less coronal (1.1° ± 0.81° vs 2.9° ± 0.93°, p < 0.001) and sagittal (1.5° ± 0.96° vs 2.1° ± 0.64°, p = 0.015) correction loss at the 2-year follow-up, and a lower incidence of intraoperative pedicle screw pullout (14.3% vs 23.8%, p = 0.026).

CONCLUSIONS

The SC technique could significantly and practically reduce the difficulty of rod installation with better deformity correction outcomes than the traditional TC technique. The SC technique was an effective alternative for patients with STIS.

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Zhe Wang, Liu Yang, Petar M. Djurić, and Michael R. Egnor

OBJECTIVE

Pseudotumor cerebri is a disorder of intracranial dynamics characterized by elevated intracranial pressure (ICP) and chronic cerebral venous hypertension without structural abnormalities. A perplexing feature of pseudotumor is the absence of the ventriculomegaly found in obstructive hydrocephalus, although both diseases are associated with increased resistance to cerebrospinal fluid (CSF) resorption. Traditionally, the pathophysiology of ventricular dilation and obstructive hydrocephalus has been attributed to the backup of CSF due to impaired absorption, and it is unclear why backup of CSF with resulting ventriculomegaly would not occur in pseudotumor. In this study, the authors used an electrical circuit model to simulate the cerebral windkessel effect and explain the presence of ventriculomegaly in obstructive hydrocephalus but not in pseudotumor cerebri.

METHODS

The cerebral windkessel is a band-stop filter that dampens the arterial blood pressure pulse in the cranium. The authors used a tank circuit with parallel inductance and capacitance to model the windkessel. The authors distinguished the smooth flow of blood and CSF and the pulsatile flow of blood and CSF by using direct current (DC) and alternating current (AC) sources, respectively. The authors measured the dampening notch from ABP to ICP as the band-stop filter of the windkessel.

RESULTS

In obstructive hydrocephalus, loss of CSF pathway volume impaired the flow of AC power in the cranium and caused windkessel impairment, to which ventriculomegaly is an adaptation. In pseudotumor, venous hypertension affected DC power flow in the capillaries but did not affect AC power or the windkessel, therefore obviating the need for adaptive ventriculomegaly.

CONCLUSIONS

In pseudotumor, the CSF spaces are unaffected and the windkessel remains effective. Therefore, ventricles remain normal in size. In hydrocephalus, the windkessel, which depends on the flow of AC power in patent CSF spaces, is impaired, and the ventricles dilate as an adaptive process to restore CSF pathway volume. The windkessel model explains both ventriculomegaly in obstructive hydrocephalus and the lack of ventriculomegaly in pseudotumor. This model provides a novel understanding of the pathophysiology of disorders of CSF dynamics and has significant implications in clinical management.

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Hao-Li Liu, Hung-Wei Yang, Mu-Yi Hua, and Kuo-Chen Wei

Malignant glioma is a severe primary CNS cancer with a high recurrence and mortality rate. The current strategy of surgical debulking combined with radiation therapy or chemotherapy does not provide good prognosis, tumor progression control, or improved patient survival. The blood-brain barrier (BBB) acts as a major obstacle to chemotherapeutic treatment of brain tumors by severely restricting drug delivery into the brain. Because of their high toxicity, chemotherapeutic drugs cannot be administered at sufficient concentrations by conventional delivery methods to significantly improve long-term survival of patients with brain tumors. Temporal disruption of the BBB by microbubble-enhanced focused ultrasound (FUS) exposure can increase CNS-blood permeability, providing a promising new direction to increase the concentration of therapeutic agents in the brain tumor and improve disease control. Under the guidance and monitoring of MR imaging, a brain drug-delivery platform can be developed to control and monitor therapeutic agent distribution and kinetics. The success of FUS BBB disruption in delivering a variety of therapeutic molecules into brain tumors has recently been demonstrated in an animal model. In this paper the authors review a number of critical studies that have demonstrated successful outcomes, including enhancement of the delivery of traditional clinically used chemotherapeutic agents or application of novel nanocarrier designs for actively transporting drugs or extending drug half-lives to significantly improve treatment efficacy in preclinical animal models.

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Mengcun Chen, Shuhua Yang, Cao Yang, Weihua Xu, Shunan Ye, Jing Wang, Yong Feng, Wen Yang, and Xianzhe Liu

OBJECTIVE

The purpose of this study was to present an initial surgical experience in the management of 1- or 2-level degenerative disc disease of the cervical spine using biodegradable anterior cervical plates (bACPs) in anterior cervical discectomy and fusion (ACDF). The authors also aimed to provide insight into this critical and controversial clinical issue by clarifying outcomes for patients receiving bACPs and by comparing their outcomes with those achieved using a traditional metallic anterior cervical plate (mACP) implant.

METHODS

A retrospective review was conducted for 2 series of patients who had undergone ACDF using either bACP (31 patients, 38 segments) or mACP (47 patients, 57 segments) instrumentation. The patients were followed up for a mean 13.5 ± 0.9 months (range 12–18 months) in the bACP group and 14.8 ± 1.5 months (range 14–22 months) in the mACP group. Clinical outcomes were determined according to scores on the visual analog scale (VAS), the modified Japanese Orthopaedic Association (mJOA) scoring system, and Odom's criteria. Radiological images were used to assess fusion rates, intervertebral height, Cobb's angle, and the width of prevertebral soft tissue.

RESULTS

Both VAS and mJOA scores were significantly improved at each follow-up in both groups. Excellent or good results according to Odom's criteria were achieved in 93.5% (29/31) of patients in the bACP group and 93.6% (44/47) of patients in the mACP group. At 6 months postoperatively, the fusion rate was 94.7% (36/38) in the bACP group and 96.5% (55/57) in the mACP group, but subsidence of the intervertebral space at the surgical level was more evident in the bACP group. Angulation, as measured by Cobb's angle, demonstrated obvious healing in both groups, while better maintenance was observed in the mACP group. The local inflammatory reaction was uneventful during follow-up. Dysphonia and dysphagia were observed in both groups during the follow-up.

CONCLUSIONS

The relatively comparable early clinical and radiographic outcomes and the overall acceptable complication rates for bACP and mACP use suggest that bACPs could be used as alternative instruments in ACDF. Mild graft resorption was noted without evidence of symptoms. However, the prospective efficacy of biodegradable instrumentation can only be elucidated with longer-term observation.