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Yao Li, Zhonghai Shen, Xiangyang Wang, Yongli Wang, Hongming Xu, Feng Zhou, Shaoyu Zhu, and Huazi Xu

OBJECT

The authors' goal in this paper was to quantify reference data on the dimensions and relationships of the maximum posterior screw angle and the thoracic spinal canal in different pediatric age groups.

METHODS

One hundred twelve pediatric patients were divided into 4 age groups, and their thoracic vertebrae were studied on CT scans. The width, depth, and maximum posterior screw angles with different screw entrance points were measured on a Philips Brilliance 16 CT. The statistical analysis was performed using the Student t-test and Pearson's correlation analysis.

RESULTS

The width and depth of the thoracic vertebrae increased from T-5 to T-12. The width ranged from 18.5 to 37.1 mm, while the depth ranged from 16.1 to 28.2 mm. The maximum posterior screw angle decreased from T-5 to T-12 in all groups. The ranges and mean angles at the entrance points were as follows: initial entrance point, 6.9° to 12.3° with a mean angle of 9.1°; second entrance point, 20.6° to 27.0° with a mean angle of 24.2°; and third entrance point, 29.2° to 37.5° with a mean angle of 33.7°. There were no significant age-related differences noted for the maximum posterior screw angles.

CONCLUSIONS

The angle decreased from T-5 to T-12. No significant age-related differences were noted in the maximum posterior screw angles. Screws should be placed between the initial and second points and parallel to the coronal section or at a slight anterior orientation.

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Yao Li, Bang-ping Qian, Yong Qiu, Shi-zhou Zhao, Xiao-lin Zhong, and Bin Wang

OBJECTIVE

The objective of this study was to investigate the impact of the lumbar sagittal profile on pelvic orientation and pelvic motion during postural changes in patients with ankylosing spondylitis (AS) and thoracolumbar kyphosis and to evaluate the potential risk of prosthetic dislocation after total hip arthroplasty (THA) following pedicle subtraction osteotomy (PSO).

METHODS

Seventy-two patients with AS-related thoracolumbar kyphosis following spinal osteotomy were retrospectively reviewed, and 21 healthy volunteers were recruited as a control group. Pre- and postoperative 2D full-body images in standing and sitting positions were obtained to evaluate the anterior pelvic plane angle (APPA), lumbar lordosis (LL), sacral slope (SS), pelvic tilt (PT), proximal femur angle (PFA), and femoroacetabular flexion during postural changes. Patients with AS were categorized in either a lordotic or kyphotic group based on the lumbar sagittal profile.

RESULTS

Significant increases in the SS and decreases in the APPA, PT, and LL were observed postoperatively in both the standing and sitting positions (p < 0.001 for all). Significantly higher APPA, PT, LL, and ΔPT, and lower SS, ΔSS, and ΔSS+ΔPFA were observed in the kyphotic group (p < 0.05). After undergoing PSO, ΔPT and ΔSS significantly decreased while femoroacetabular flexion significantly increased in both AS groups (p < 0.05), and no significant difference was present between the two groups (p > 0.05). Bath Ankylosing Spondylitis Radiology Hip Index scores in the kyphotic group were significantly worse than those in the lordotic group pre- and postoperatively (p < 0.05). No significant difference in parameters concerning pelvic motion (ΔAPPA, ΔPT, and ΔSS) was found when PSO was performed in the thoracolumbar or lumbar spine.

CONCLUSIONS

Lumbar sagittal profiles greatly affect pelvic orientation and pelvic motion in AS. When THA is performed before PSO, AS patients with lumbar kyphosis are at higher risk of anterior prosthetic dislocation, while those with lordotic lumbar sagittal profiles are at higher risk of posterior dislocation. PSO should be performed prior to THA. After PSO, further decreased pelvic motion indicated a potential risk of posterior prosthetic dislocation after sequential THA, whereas theoretically patients with preoperative lumbar kyphosis are at higher risk of THA dislocation. The site where PSO was performed (thoracolumbar or lumbar spine) does not influence the risk of THA dislocation.

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Xin-Yi Gao, Qiao Li, Jing-Run Li, Qian Zhou, Jian-Xun Qu, and Zhen-Wei Yao

OBJECTIVE

The authors conducted a study to noninvasively and nonradioactively reveal moyamoya disease (MMD) intracerebral perfusion and perfusion territory supplied by the unilateral internal carotid artery (ICA) and external carotid artery (ECA) and bilateral vertebral arteries (VAs) before surgery and to further identify risk factors for preoperative hemorrhage in adult MMD.

METHODS

Forty-three consecutive adult patients with bilateral MMD underwent unenhanced T1-weighted MRI, territorial arterial spin labeling (t-ASL), and unenhanced 3D time-of-flight MRA (3D-TOF-MRA). Clinical factors, including age, sex, hypertension, diabetes mellitus, hyperlipidemia, current smoking status, and history of taking aspirin, were gathered and stratified. Univariate logistic regression analyses were used to examine the relationship between various risk factors and the occurrence of preoperative hemorrhage. Stepwise multivariate logistic regression analyses were used to determine independent risk factors of preoperative hemorrhage in MMD.

RESULTS

Among the 86 MMD hemispheres, t-ASL revealed 137 perfusion territory shifts in 79 hemispheres. Five distinct categories of perfusion territory shifts were observed on t-ASL maps. The subtypes of perfusion territory shift on t-ASL maps were further subdivided into 2 different categories, group A and group B, in combination with findings on 3D-TOF-MRA. A perfusion territory shift attributable solely to the secondary collaterals was a potential independent risk factor for preoperative hemorrhage (p = 0.026; 95% CI 1.201–18.615; OR 4.729). After eliminating the influence of the secondary collaterals, the primary collaterals had no significant effect on the risk of preoperative hemorrhage (p = 0.182).

CONCLUSIONS

t-ASL could reveal comprehensive MMD cerebral blood perfusion and the vivid perfusion territory shifts fed by the unilateral ICA and ECA and bilateral VAs in a noninvasive, straightforward, nonradioactive, and nonenhanced manner. 3D-TOF-MRA could subdivide t-ASL perfusion territory shifts according to their shunt arteries. A perfusion territory shift attributable to the secondary collaterals is a potential independent risk factor for preoperative hemorrhage in MMD patients. A perfusion territory shift fed by the primary collaterals may not have a strong effect on preoperative hemorrhage in MMD patients. These findings make the combined modalities of t-ASL and 3D-TOF-MRA a feasible tool for MMD disease assessment, management, and surgical strategy planning.

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Keyi Zhang, Ming Shen, Nidan Qiao, Zhengyuan Chen, Wenqiang He, Zengyi Ma, Xuefei Shou, Shiqi Li, Yao Zhao, Li Pan, Dan Liu, Min He, Zhaoyun Zhang, Yiming Li, Zhenwei Yao, Hongying Ye, and Yongfei Wang

OBJECTIVE

The primary aim of this study was to investigate the value of multidisciplinary team (MDT) management in treating patients with Cushing’s disease (CD). The secondary aim was to assess the concordance of bilateral inferior petrosal sinus sampling (BIPSS) lateralization with intraoperative observations.

METHODS

The authors recruited 124 consecutive patients (128 procedures) who had undergone endoscopic endonasal resection of adrenocorticotropic hormone–secreting pituitary adenomas from May 2014 to April 2018 and assessed their clinical characteristics, surgical outcomes, and adjuvant therapies. The criteria for surgical remission were normalized serum and urinary cortisol levels, which could be suppressed by a low-dose dexamethasone suppression test at 3-months’ follow-up without adjuvant treatment.

RESULTS

The remission rates of the 113 patients with long-term follow-up (20.3 ± 12.2 months) were 83.2% after surgery alone and 91.2% after adjuvant therapy. The surgical remission rates of macroadenomas, MRI-visible microadenomas, and MRI-negative tumors were 66.7% (12/18), 89.3% (67/75), and 75% (15/20), respectively (p = 0.039). The surgical remission rates had a trend of improvement during the study period (87.5% in 2017–2018 vs 76.5% in 2014, p = 0.517). Multivariate regression analysis showed that a history of previous pituitary surgery (OR 0.300, 95% CI 0.100–0.903; p = 0.032) and MRI-visible microadenoma (OR 3.048, 95% CI 1.030–9.019; p = 0.044) were independent factors influencing surgical remission. The recurrence rate was 3.2% after a mean of 18 months after surgery. The remission rate of postoperative MDT management in patients with persistent disease was higher than non-MDT management (66.7% vs 0%, p = 0.033). In cases with preoperative BIPSS lateralization, 84.6% (44/52) were concordant with intraoperative findings.

CONCLUSIONS

MRI-visible microadenoma and primary surgery were independent predictors of surgical remission in CD. The MDT management strategy helps to achieve a better overall outcome. BIPSS may help to lateralize the tumor in MRI-negative/equivocal microadenomas.

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Nai-Feng Tian, Ai-Min Wu, Li-Jun Wu, Xin-Lei Wu, Yao-Sen Wu, Xiao-Lei Zhang, Hua-Zi Xu, and Yong-Long Chi

Object

This study aimed to investigate the incidence rate of heterotopic ossification (HO) after implantation of Coflex interspinous devices. Possible risk factors associated with HO were evaluated.

Methods

The authors retrospectively analyzed patients who had undergone single-level (L4–5) implantation of a Coflex device for the treatment of lumbar spinal stenosis. Patient data recorded were age, sex, height, weight, body mass index, smoking habits, and surgical time. Heterotopic ossification was identified through lumbar anteroposterior and lateral view radiographs. The authors developed a simple classification for defining HO and compared HO-positive and HO-negative cases to identify possible risk factors.

Results

Among 32 patients with follow-up times of 24–57 months, HO was detectable in 26 (81.2%). Among these 26 patients, HO was in the lateral space of the spinous process but not in the interspinous space in 8, HO was in the interspinous space but did not bridge the adjacent spinous process in 16, and interspinous fusion occurred at the level of the device in 2. Occurrence of HO was not associated with patient age, sex, height, weight, body mass index, smoking habits, or surgical time.

Conclusions

A high incidence of HO has been detected after implantation of Coflex devices. Clinicians should be aware of this possible outcome, and more studies should be conducted to clarify the clinical effects of HO.

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Liang-Hua Ma, Guang Li, Hong-Wei Zhang, Zhi-Yu Wang, Jun Dang, Shuo Zhang, Lei Yao, and Xiao-Meng Zhang

Object

This study was undertaken to analyze outcomes in patients with newly diagnosed brain metastases from non–small cell lung cancer (NSCLC) who were treated with hypofractionated stereotactic radiotherapy (HSRT) with or without whole-brain radiotherapy (WBRT).

Methods

One hundred seventy-one patients comprised the study population. Fifty-four patients received HSRT alone, and 117 patients received both HSRT and WBRT. The median survival time (MST) was determined using the Kaplan-Meier method. Recursive Partitioning Analysis (RPA) and Graded Prognostic Assessment (GPA) were also used to evaluate the results. Univariate and multivariate analyses were performed to determine significant prognostic factors for overall survival. Tumor control, radiation toxicity, and cause of death in the HSRT and HSRT+WBRT groups were evaluated.

Results

The MST for all patients was 13 months. According to the Kaplan-Meier method, the probability of survival at 1, 2, and 3 years was 51.2%, 21.7%, and 10.1%. The MSTs for RPA Classes I, II, and III were 19, 12, and 5 months, respectively; and the MSTs for GPA Scores 4, 3, 2, and 1 were 24, 14, 12, and 6 months, respectively. The MSTs in the HSRT+WBRT and HSRT groups were 13 and 9 months (p = 0.044), respectively, for all patients, 13 and 8 months (p = 0.031), respectively, for patients with multiple brain metastases, and 16 and 15 months (p = 0.261), respectively, for patients with a single brain metastasis. The multivariate analysis showed that HSRT+WBRT was a significant factor only for patients with multiple brain metastases (p = 0.010). The Kaplan-Meier–estimated tumor control rates at 3, 6, 9, and 12 months were 92.2%, 82.7%, 79.5%, and 68.3% in the HSRT+WBRT group and 73.5%, 58.4%, 51.0%, and 43.3% in the HSRT group, respectively, in all 165 patients (p = 0.001). The estimated tumor control rates at 3, 6, 9, and 12 months were 94.3%, 81.9%, 79.6%, and 76.7%, respectively, in the HSRT+WBRT group and 77.8%, 61.4%, 52.6%, and 48.2%, respectively, in the HSRT group in the 80 patients harboring a single metastasis (p = 0.009). The estimated tumor control rates at 3, 6, 9, and 12 months were 90.5%, 83.5%, 79.5%, and 60.9%, respectively, in the HSRT+WBRT group and 68.2%, 54.5%, 48.5%, and 36.4%, respectively, in the HSRT group in the 85 patients with multiple metastases (p = 0.010). The toxicity incidences of Grade 3 or worse were 6.0% (7 of 117 patients) in the HSRT+WBRT group and 1.9% (1 of 54 patients) in the HSRT group (p = 0.438). The differences in neurological death rates between the HSRT+WBRT group and the HSRT group were not statistically significant (34.4% vs 44.7%, p = 0.125, in all patients; 30.0% vs 52.0%, p = 0.114, in patients with a single metastasis; and 38.0% vs 36.4%, p = 0.397, in patients with multiple metastases).

Conclusions

The overall survival results in the present study were similar to those in other studies. Hypofractionated stereotactic radiotherapy provides an alternative method to traditional stereotactic radiosurgery. We suggest that WBRT should be combined with HSRT in patients with single or multiple newly diagnosed brain metastases from NSCLC.

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Peng Xu, Wei-Ming Gong, Yao Li, Tao Zhang, Kai Zhang, De-Zhen Yin, and Tang-Hong Jia

Object

Chronic mechanical compression of the spinal cord, which is commonly caused by degeneration of the spine, impairs motor and sensory functions insidiously and progressively. Yet the exact mechanisms of chronic spinal cord compression (SCC) remain to be elucidated. To study the pathophysiology of this condition, the authors developed a simple animal experimental model that reproduced the clinical course of mechanical compression of the spinal cord.

Methods

A custom-designed compression device was implanted on the exposed spinal cord of female Wistar rats between the T-7 and T-9 vertebrae. A root canal screw attached to a plastic plate was tightened 1 complete turn (1 pitch) every 7 days for 6 weeks. The placement of the compression device and the degree of compression were validated every week using radiography. Furthermore, a motor sensory deficit index was also calculated every week. After 3, 6, 9, or 12 weeks, the compressed T7–9 spinal cords were harvested and examined histologically.

Results

Lateral projection of the thoracic spine showed a progressively increasing rate of mean spinal cord narrowing in the compression group. Motor and sensory deficiencies were observed from Week 3 onward; paralysis was observed in 2 rats at Week 12. Motor deficiency appeared earlier than sensory deficiency. Obvious pathological changes were observed starting at Week 6. The number of neurons in the gray matter of rats with chronic compression of the spinal cord decreased progressively in the 6- and 9-week compression groups. In the white matter, myelin destruction and loss of axons and glia were noted. The number of terminal deoxynucleotidyl transferase–mediated deoxyuridine triphosphate nick-end labeling (TUNEL)–positive neurons increased in the ventral-to-dorsal direction. The number of TUNEL-positive cells increased from Week 6 onward and peaked at Week 9.

Conclusions

This practical model accurately reproduces characteristic features of clinical chronic SCC, including progressive motor and sensory disturbances after a latency and insidious neuronal loss.

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Shun Yao, Farhana Akter, Ru-Yuan Zhang, and Zhouyue Li

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Bing Zhao, Yu-Kui Wei, Gui-Lin Li, Yong-Ning Li, Yong Yao, Jun Kang, Wen-Bin Ma, Yi Yang, and Ren-Zhi Wang

Object

The standard transsphenoidal approach has been successfully used to resect most pituitary adenomas. However, as a result of the limited exposure provided by this procedure, complete surgical removal of pituitary adenomas with parasellar or retrosellar extension remains problematic. By additional bone removal of the cranial base, the extended transsphenoidal approach provides better exposure to the parasellar and clival region compared with the standard approach. The authors describe their surgical experience with the extended transsphenoidal approach to remove pituitary adenomas invading the anterior cranial base, cavernous sinus (CS), and clivus.

Methods

Retrospective analysis was performed in 126 patients with pituitary adenomas that were surgically treated via the extended transsphenoidal approach between September 1999 and March 2008. There were 55 male and 71 female patients with a mean age of 43.4 years (range 12–75 years). There were 82 cases of macroadenoma and 44 cases of giant adenoma.

Results

Gross-total resection was achieved in 78 patients (61.9%), subtotal resection in 43 (34.1%), and partial resection in 5 (4%). Postoperative complications included transient cerebrospinal rhinorrhea (7 cases), incomplete cranial nerve palsy (5), panhypopituitarism (5), internal carotid artery injury (2), monocular blindness (2), permanent diabetes insipidus (1), and perforation of the nasal septum (2). No intraoperative or postoperative death was observed.

Conclusions

The extended transsphenoidal approach provides excellent exposure to pituitary adenomas invading the anterior cranial base, CS, and clivus. This approach enhances the degree of tumor resection and keeps postoperative complications relatively low. However, radical resection of tumors that are firm, highly invasive to the CS, or invading multidirectionally remains a big challenge. This procedure not only allows better visualization of the tumor and the neurovascular structures but also provides significant working space under the microscope, which facilitates intraoperative manipulation. Preoperative imaging studies and new techniques such as the neuronavigation system and the endoscope improve the efficacy and safety of tumor resection.

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Xin Zhang, Tamrakar Karuna, Zhi-Qiang Yao, Chuan-Zhi Duan, Xue-Min Wang, Shun-Ting Jiang, Xi-Feng Li, Jia-He Yin, Xu-Ying He, Shen-Quan Guo, Yun-Chang Chen, Wen-Chao Liu, Ran Li, and Hai-Yan Fan

OBJECTIVE

Among clinical and morphological criteria, hemodynamics is the main predictor of aneurysm growth and rupture. This study aimed to identify which hemodynamic parameter in the parent artery could independently predict the rupture of anterior communicating artery (ACoA) aneurysms by using multivariate logistic regression and two-piecewise linear regression models. An additional objective was to look for a more simplified and convenient alternative to the widely used computational fluid dynamics (CFD) techniques to detect wall shear stress (WSS) as a screening tool for predicting the risk of aneurysm rupture during the follow-up of patients who did not undergo embolization or surgery.

METHODS

One hundred sixty-two patients harboring ACoA aneurysms (130 ruptured and 32 unruptured) confirmed by 3D digital subtraction angiography at three centers were selected for this study. Morphological and hemodynamic parameters were evaluated for significance with respect to aneurysm rupture. Local hemodynamic parameters were obtained by MR angiography and transcranial color-coded duplex sonography to calculate WSS magnitude. Multivariate logistic regression and a two-piecewise linear regression analysis were performed to identify which hemodynamic parameter independently characterizes the rupture status of ACoA aneurysms.

RESULTS

Univariate analysis showed that WSS (p < 0.001), circumferential wall tension (p = 0.005), age (p < 0.001), the angle between the A1 and A2 segments of the anterior cerebral artery (p < 0.001), size ratio (p = 0.023), aneurysm angle (p < 0.001), irregular shape (p = 0.005), and hypertension (grade II) (p = 0.006) were significant parameters. Multivariate analyses showed significant association between WSS in the parent artery and ACoA aneurysm rupture (p = 0.0001). WSS magnitude, evaluated by a two-piecewise linear regression model, was significantly correlated with the rupture of the ACoA aneurysm when the magnitude was higher than 12.3 dyne/cm2 (HR 7.2, 95% CI 1.5–33.6, p = 0.013).

CONCLUSIONS

WSS in the parent artery may be one of the reliable hemodynamic parameters characterizing the rupture status of ACoA aneurysms when the WSS magnitude is higher than 12.3 dyne/cm2. Analysis showed that with each additional unit of WSS (even with a 1-unit increase of WSS), there was a 6.2-fold increase in the risk of rupture for ACoA aneurysms.