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Chuan-Tao Zuo, Xu-Yun Hua, Yi-Hui Guan, Wen-Dong Xu, Jian-Guang Xu and Yu-Dong Gu

Object

Peripheral nerve injury in a limb usually causes intrahemispheric functional reorganization of the contralateral motor cortex. Recently, evidence has been emerging for significant interhemispheric cortical plasticity in humans, mostly from studies of direct cortical damage. However, in this study, a long-range interhemispheric plasticity was demonstrated in adults with brachial plexus avulsion injury (BPAI) who had received a contralateral cervical nerve transfer, and this plasticity reversed the BPAI-induced intrahemispheric cortical reorganization.

Methods

In this study, 8 adult male patients with BPAI were studied using PET scanning.

Results

The results indicated that the right somatomotor cortices, which may contribute to the control of the injured limb before brachial plexus deafferentation, still played an important role when patients with BPAI tried to move their affected limbs, despite the fact that the contralateral C-7 nerve transfer had been performed and the peripheral output had changed dramatically. Such findings are consistent with the results of the authors' previous animal study.

Conclusions

The brain may try to restore the control of an injured limb to its original cortex area, and a complicated change of peripheral pathway also can induce long-range interhemispheric cortical reorganization in human motor cortex.

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Jun Pan, Songtao Qi, Yi Liu, Yuntao Lu, Junxiang Peng, XiAn Zhang, YiKai Xu, Guang-long Huang and Jun Fan

OBJECT

Craniopharyngiomas (CPs) are rare epithelial tumors that are often associated with an enigmatic and unpredictable growth pattern. Understanding the growth patterns of these tumors has a direct impact on surgical planning and may enhance the safety of radical tumor removal. The aim of this study was to analyze the growth patterns and surgical treatment of CPs with a focus on the involvement of the hypothalamopituitary axis and the relationship of the tumor to the arachnoid membrane and surrounding structures.

METHODS

Clinical data from 226 consecutive patients with primary CP were retrospectively reviewed. Tumor location and the relationship of the tumor to the third ventricle floor and the pituitary stalk were evaluated using preoperative MRI and intraoperative findings. A topographic classification scheme was proposed based on the site of tumor origin and tumor development. The clinical relevance of this classification on patient presentation and outcomes was also analyzed.

RESULTS

The growth of CPs can be broadly divided into 3 groups based on the site of tumor origin and on tumor-meningeal relationships: Group I, infrasellar/infradiaphragmatic CPs (Id-CPs), which mainly occurred in children; Group II, suprasellar subarachnoid extraventricular CPs (Sa-CPs), which were mainly observed in adults and rarely occurred in children; and Group III, suprasellar subpial ventricular CPs (Sp-CPs), which commonly occurred in both adults and children. Tumors in each group may develop complex growth patterns during vertical expansion along the pituitary stalk. Tumor growth patterns were closely related to both clinical presentation and outcomes. Patients with Sp-CPs had more prevalent weight gain than patients with Id-CPs or Sa-CPs; the rates of significant weight gain were 41.7% for children and 16.7% for adults with Sp-CPs, 2.2% and 7.1% for those with Id-CPs, and 12.5% and 2.6% for those with Sa-CPs (p < 0.001). Moreover, patients with Sp-CPs had increased hypothalamic dysfunction after radical removal; 39% of patients with Sp-CPs, 14.5% with Id-CPs, and 17.4% with Sa-CPs had high-grade hypothalamic dysfunction in the first 2 postoperative years (p < 0.001).

CONCLUSIONS

The classification of CPs based on growth pattern may elucidate the best course of treatment for this formidable tumor. More tailored, individualized surgical strategies based on tumor growth patterns are mandatory to provide long-term tumor control and to minimize damage to hypothalamic structures. Differences in the distribution of growth patterns between children and adults imply that hierarchical comparison is necessary when investigating outcomes and survival across treatment paradigms in patients with CP.

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Yi Ping Zhang, Christopher Iannotti, Lisa B. E. Shields, Yingchun Han, Darlene A. Burke, Xiao-Ming Xu and Christopher B. Shields

Object. Laceration-induced spinal cord injury (SCI) results in the invasion of a connective tissue scar, progressive damage to the spinal cord due to complex secondary injury mechanisms, and axonal dieback of descending motor pathways. The authors propose that preparation of the spinal cord for repair strategies should include hematoma removal and dural closure, resulting in apposition of the severed ends of the spinal cord. Such procedures may reduce the size of the postinjury spinal cord cyst as well as limit scar formation.

Methods. Using a novel device, the Vibraknife, the authors created a dorsal hemisection of the spinal cord at C-6 in the adult rat. In Group 1 (eight rats), the dura mater was repaired with apposition of the two stumps of the spinal cord to reduce the lesion gap. In Group 2 (10 rats), the dura was not closed and the two cord stumps were not approximated. All rats were killed at 4 weeks postinjury, and the spinal cords from each group were removed and examined using histological, stereological, and immunohistochemical methods.

In Group 1 rats a significant reduction of the total lesion volume and connective tissue scar was observed compared with those in Group 2 (Student t-test, p < 0.05). Approximation of the stumps did not promote the regeneration of corticospinal tract fibers or sensory axons through the lesion site.

Conclusions. Apposition of the severed ends of the spinal cord by dural closure reduces the lesion gap, cystic cavitation, and connective tissue scar formation. These outcomes may collectively reduce secondary tissue damage at the injury site and shorten the length of the lesion gap, which will facilitate transplantation-mediated axonal regeneration after laceration-induced SCI.

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Fengping Zhu, Yi Qian, Bin Xu, Yuxiang Gu, Kaavya Karunanithi, Wei Zhu, Liang Chen, Ying Mao and Michael K. Morgan

OBJECTIVE

Although intracranial vessel remodeling has been observed in moyamoya disease, concerns remain regarding the effect of bypass surgery on hemodynamic changes within the internal carotid artery (ICA). The authors aimed to quantify the surgical effect of bypass surgery on bilateral ICAs in moyamoya disease and to estimate pressure drop (PD) along the length of the ICA to predict surgical outcomes.

METHODS

Records of patients who underwent bypass surgery for treatment of moyamoya disease and in whom flow rates were obtained pre- and postsurgery by quantitative MR angiography were retrospectively reviewed. Quantitative MR angiography and computational fluid dynamics were applied to measure morphological and hemodynamic changes during pre- and postbypass procedures. The results for vessel diameter, volumetric flow, PD, and mean wall shear stress along the length of the ICA were analyzed. Subgroup analysis was performed for the circle of Willis (CoW) configurations.

RESULTS

Twenty-three patients were included. The PD in ICAs on the surgical side (surgical ICAs) decreased by 21.18% (SD ± 30.1%) and increased by 11.75% (SD ± 28.6%) in ICAs on the nonsurgical side (contralateral ICAs) (p = 0.001). When the PD in contralateral ICAs was compared between patients with a complete or incomplete CoW, the authors found that the PDI in the former group decreased by 2.45% and increased by 20.88% in the latter (p = 0.05). Regression tests revealed that a greater postoperative decrease in PD corresponded to shrinking of ICAs (R2 = 0.22, p = 0.02).

CONCLUSIONS

PD may be used as a reliable biomechanical indicator for the assessment of surgical treatment outcomes. The vessel remodeling characteristics of contralateral ICA were related to CoW configurations.

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Ya-Bin Ji, Yong-Ming Wu, Zhong Ji, Wei Song, Sui-Yi Xu, Yao Wang and Su-Yue Pan

Object

Intracarotid artery cold saline infusion (ICSI) is an effective method for protecting brain tissue, but its use is limited because of undesirable secondary effects, such as severe decreases in hematocrit levels, as well as its relatively brief duration. In this study, the authors describe and investigate the effects of a novel ICSI pattern (interrupted ICSI) relative to the traditional method (uninterrupted ICSI).

Methods

Ischemic strokes were induced in 85 male Sprague-Dawley rats by occluding the middle cerebral artery for 3 hours using an intraluminal filament. Uninterrupted infusion groups received an infusion at 15 ml/hour for 30 minutes continuously. The same infusion speed was used in the interrupted infusion groups, but the whole duration was divided into trisections, and there was a 20-minute interval without infusion between sections. Forty-eight hours after reperfusion, H & E and silver nitrate staining were utilized for morphological assessment. Infarct sizes and brain water contents were determined using H & E staining and the dry-wet weight method, respectively. Levels of neuron-specific enolase (NSE), S100β protein, and matrix metalloproteinase 9 (MMP-9) in the serum were determined using enzyme-linked immunosorbent assay. Neurological deficits were also evaluated.

Results

Histology showed that interrupted ICSI did not affect neurons or fibers in rat brains, which suggests that this method is safe for brain tissues with ischemia. The duration of hypothermia induced by interrupted ICSI was longer than that induced via the traditional method, and the decrease in hematocrit levels was less pronounced. There were no differences in infarct size or brain water content between uninterrupted and interrupted ICSI groups, but neuron-specific enolase and matrix metalloproteinase 9 serum levels were more reduced after interrupted ICSI than after the traditional method.

Conclusions

Interrupted ICSI is a safe method. Compared with traditional ICSI, the interrupted method has a longer duration of hypothermia and less effect on hematocrit and offers more potentially improved neuroprotection, thereby making it more attractive as an infusion technique in the clinic.

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Sheng-Tzung Tsai, Hsin-Chi Tsai, Chung-Chih Kuo, Hsiang-Yi Hung, Chien-Hui Lee and Shin-Yuan Chen

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Qiao Zuo, Pengfei Yang, Nan Lv, Qinghai Huang, Yu Zhou, Xiaoxi Zhang, Guoli Duan, Yina Wu, Yi Xu, Bo Hong, Rui Zhao, Qiang Li, Yibin Fang, Kaijun Zhao, Dongwei Dai and Jianmin Liu

OBJECTIVE

The authors compared the contemporary perioperative procedure-related complications between coiling with stent placement and coiling without stent placement for acutely ruptured aneurysms treated in a single center after improvement of interventional skills and strategy.

METHODS

In an institutional review board–approved protocol, 133 patients who underwent coiling with stent placement and 289 patients who underwent coiling without stent placement from January 2012 to December 2014 were consecutively reviewed retrospectively. Baseline characteristics, procedure-related complications and mortality rate, angiographic follow-up results, and clinical outcomes were compared between the two groups. Univariate analysis and logistic regression analysis were performed to determine the association of procedure-related complications of coiling with stent placement with potential risk factors.

RESULTS

The coiling/stent group and coiling/no-stent group were statistically comparable with respect to all baseline characteristics except for aneurysm location (p < 0.001) and parent artery configuration (p = 0.024). The immediate embolization results and clinical outcomes between the two groups showed no significant differences (p = 0.807 and p = 0.611, respectively). The angiographic follow-up results of the coiling in stent group showed a significant higher occlusion rate and lower recurrence rate compared with the coiling/no-stent group (82.5% vs 66.7%, 3.5% vs 14.5%, p = 0.007). Procedure-related intraoperative rupture and thrombosis, postoperative early rebleeding and thrombosis, and external ventricular drainage–related hemorrhagic event occurred in 3.0% (4 of 133), 2.3% (3 of 133), 1.5% (2 of 133), 0.7% (1 of 133), and 0.8% (1 of 133) of the coiling/stent group compared with 1.0% (3 of 289), 1.4% (4 of 289), 1.4% (4 of 289), and 0.7% (2 of 289) of the coiling/no-stent group, respectively (p = 0.288, p = 0.810, p = 1.000, p = 0.315, and p = 1.000, respectively). One patient presented with coil protrusion in the group of coiling without stent. The procedure-related mortality was 1.5% (2 of 133) in the coiling/stent group and 0.7% in the coiling/no-stent group (p = 0.796). Multivariable analysis showed no significant predictors for the total perioperative procedure-related complications, hemorrhagic complications, or ischemic complications.

CONCLUSIONS

The perioperative procedure-related complications and mortality rate did not differ significantly between the coiling/stent group and the coiling/no-stent group for patients with acutely ruptured aneurysms. Considering the better angiographic follow-up results, coiling with stent placement might be a feasible, safe, and promising option for treatment in the acute phase of selected wide-necked ruptured intracranial aneurysms.

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Nasser Mohammed, Dale Ding, Yi-Chieh Hung, Zhiyuan Xu, Cheng-Chia Lee, Hideyuki Kano, Roberto Martínez-Álvarez, Nuria Martínez-Moreno, David Mathieu, Mikulas Kosak, Christopher P. Cifarelli, Gennadiy A. Katsevman, L. Dade Lunsford, Mary Lee Vance and Jason P. Sheehan

OBJECTIVE

The role of primary stereotactic radiosurgery (SRS) in patients with medically refractory acromegaly who are not operative candidates or who refuse resection is poorly understood. The aim of this multicenter, matched cohort study was to compare the outcomes of primary versus postoperative SRS for acromegaly.

METHODS

The authors reviewed an International Radiosurgery Research Foundation database of 398 patients with acromegaly who underwent SRS and categorized them into primary or postoperative cohorts. Patients in the primary SRS cohort were matched, in a 1:2 ratio, to those in the postoperative SRS cohort, and the outcomes of the 2 matched cohorts were compared.

RESULTS

The study cohort comprised 78 patients (median follow-up 66.4 months), including 26 and 52 in the matched primary and postoperative SRS cohorts, respectively. In the primary SRS cohort, the actuarial endocrine remission rates at 2 and 5 years were 20% and 42%, respectively. The Cox proportional hazards model showed that a lower pre-SRS insulin-like growth factor–1 level was predictive of initial endocrine remission (p = 0.03), whereas a lower SRS margin dose was predictive of biochemical recurrence after initial remission (p = 0.01). There were no differences in the rates of radiological tumor control (p = 0.34), initial endocrine remission (p = 0.23), biochemical recurrence after initial remission (p = 0.33), recurrence-free survival (p = 0.32), or hypopituitarism (p = 0.67) between the 2 matched cohorts.

CONCLUSIONS

Primary SRS has a reasonable benefit-to-risk profile for patients with acromegaly in whom resection is not possible, and it has similar outcomes to endocrinologically comparable patients who undergo postoperative SRS. SRS with medical therapy in the latent period can be used as an alternative to surgery in selected patients who cannot or do not wish to undergo resection.

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Yi-Chieh Hung, Cheng-Chia Lee, Huai-che Yang, Nasser Mohammed, Kathryn N. Kearns, Ahmed M. Nabeel, Khaled Abdel Karim, Reem M. Emad Eldin, Amr M. N. El-Shehaby, Wael A. Reda, Sameh R. Tawadros, Roman Liscak, Jana Jezkova, L. Dade Lunsford, Hideyuki Kano, Nathaniel D. Sisterson, Roberto Martínez Álvarez, Nuria E. Martínez Moreno, Douglas Kondziolka, John G. Golfinos, Inga Grills, Andrew Thompson, Hamid Borghei-Razavi, Tanmoy Kumar Maiti, Gene H. Barnett, James McInerney, Brad E. Zacharia, Zhiyuan Xu and Jason P. Sheehan

OBJECTIVE

The most common functioning pituitary adenoma is prolactinoma. Patients with medically refractory or residual/recurrent tumors that are not amenable to resection can be treated with stereotactic radiosurgery (SRS). The aim of this multicenter study was to evaluate the role of SRS for treating prolactinomas.

METHODS

This retrospective study included prolactinomas treated with SRS between 1997 and 2016 at ten institutions. Patients’ clinical and treatment parameters were investigated. Patients were considered to be in endocrine remission when they had a normal level of prolactin (PRL) without requiring dopamine agonist medications. Endocrine control was defined as endocrine remission or a controlled PRL level ≤ 30 ng/ml with dopamine agonist therapy. Other outcomes were evaluated including new-onset hormone deficiency, tumor recurrence, and new neurological complications.

RESULTS

The study cohort comprised 289 patients. The endocrine remission rates were 28%, 41%, and 54% at 3, 5, and 8 years after SRS, respectively. Following SRS, 25% of patients (72/289) had new hormone deficiency. Sixty-three percent of the patients (127/201) with available data attained endocrine control. Three percent of patients (9/269) had a new visual complication after SRS. Five percent of the patients (13/285) were recorded as having tumor progression. A pretreatment PRL level ≤ 270 ng/ml was a predictor of endocrine remission (p = 0.005, adjusted HR 0.487). An increasing margin dose resulted in better endocrine control after SRS (p = 0.033, adjusted OR 1.087).

CONCLUSIONS

In patients with medically refractory prolactinomas or a residual/recurrent prolactinoma, SRS affords remarkable therapeutic effects in endocrine remission, endocrine control, and tumor control. New-onset hypopituitarism is the most common adverse event.