The Application of Biomaterials in Spinal Cord Injury.

The spinal cord and the brain form the central nervous system (CNS), which is the most important part of the body. However, spinal cord injury (SCI) caused by external forces is one of the most difficult types of neurological injury to treat, resulting in reduced or even absent motor, sensory and autonomic functions. It leads to the reduction or even disappearance of motor, sensory and self-organizing nerve functions. Currently, its incidence is increasing each year worldwide. Therefore, the development of treatments for SCI is urgently needed in the clinic. To date, surgery, drug therapy, stem cell transplantation, regenerative medicine, and rehabilitation therapy have been developed for the treatment of SCI. Among them, regenerative biomaterials that use tissue engineering and bioscaffolds to transport cells or drugs to the injured site are considered the most promising option. In this review, we briefly introduce SCI and its molecular mechanism and summarize the application of biomaterials in the repair and regeneration of tissue in various models of SCI. However, there is still limited evidence about the treatment of SCI with biomaterials in the clinic. Finally, this review will provide inspiration and direction for the future study and application of biomaterials in the treatment of SCI.

Estrogen-Mediated MicroRNA-101-3p Expression Represses Hyaluronan Synthase 2 in Synovial Fibroblasts From Idiopathic Condylar Resorption Patients.

PURPOSE: Idiopathic condylar resorption (ICR) is an aggressive form of osteoarthritis that is frequently observed in adolescent female patients. We hypothesized that an estrogen-mediated pathway may contribute to ICR development. MATERIALS AND METHODS: An enzyme-linked immunosorbent assay was used to detect the levels of estradiol (E2) and hyaluronan in synovial fluid. Immunohistochemistry, real-time polymerase chain reaction, and Western blotting were used to detect the expression of microRNAs (miRNAs) and related genes after transfection of miRNA-101-3p mimics, inhibitor, or short interfering RNA into synovial fibroblasts. Dual-luciferase activity was determined to identify the direct effect of miRNA-101-3p on hyaluronan synthase 2 (HAS2). Linear regression analysis, the nonparametric Mann-Whitney U test, the Student t test, and 1-way analysis of variance were carried out to analyze the results of each group. RESULTS: The relationship between hyaluronan and E2 was negatively correlated in synovial fluid (Pearson r = -0.3179, P = .0230). Among the screened miRNAs, miRNA-101-3p was the most overexpressed in ICR. E2 mostly upregulated the expression of miRNA-101-3p at a dose of 10 nmol/L 12 hours after transfection in synovial fibroblasts of patients with ICR. However, E2 induction of miRNA-101-3p expression was significantly repressed by estrogen receptor α interference (P = 0.0286). The dual-luciferase assay showed that miRNA-101-3p regulated the expression of HAS2 by directly targeting its 3' untranslated region. CONCLUSIONS: We speculate that E2 regulates HAS2 expression by targeting miRNA-101-3p in synovial fibroblasts of patients with ICR. Thus, the E2-miRNA-101-3p-HAS2 pathway might play an important role in the pathogenesis of ICR.

Preoperative embolization of hypervascular pediatric brain tumors: evaluation of technical safety and outcome.

BACKGROUND: Surgical management of pediatric hypervascular brain tumors is challenging because of the risk of bleeding. We sought to evaluate the technical factors associated with safety and outcome of preoperative embolization of pediatric hypervascular brain tumors. MATERIALS AND METHODS: Eight pediatric brain tumor patients received preoperative endovascular embolization during the past 8 years. The cases included four choroid plexus papillomas, one yolk sac tumor, one intraventricular meningioma, one astrocytoma, and one hemangioblastoma. Embolization was done by superselection of the feeding arteries with microcatheters followed by slow injection of either n-butyl 2-cyanoacrylate (NBCA) or tris-acryl gelatin microspheres (Embosphere). Surgery for tumor removal was done in the same session right after embolization in all but one patient. Blood loss during surgery and clinical outcome were recorded. RESULTS: Preoperative embolization was successfully done in all patients. Technical complication was noted in two patients. One patient developed bleeding while embolizing the tumor with Embospheres but was immediately embolized with NBCA without sequel. The other patient experienced tumor bleeding 4 h after embolization with Embospheres, and suffered left hemiparesis despite an emergency surgery. Surgical intervention was successfully done in all patients without procedure-related complication. Surgical blood loss ranged from 50 to 1,600 ml. CONCLUSION: Though associated with the risk of procedure-related bleeding, preoperative embolization of pediatric hypervascular brain tumors has high technical success rates and can enhance the surgical management. We suggest to perform the embolization and surgery in a single session and to use NBCA as the embolic agent to minimize the procedure-related risk.

Traumatic indirect carotid cavernous fistulas: angioarchitectures and results of transarterial embolization by liquid adhesives in 11 patients.

BACKGROUND: The angioarchitectures of traumatic indirect CCFs and the effectiveness and safety of transarterial liquid adhesive embolization for these fistulas remain to be evaluated. METHODS: A total of 276 consecutive patients with traumatic craniofacial arteriovenous fistula were referred for embolization in the past 15 years. Eleven had traumatic indirect CCFs and were managed with transarterial liquid adhesive embolization. This group was composed of 8 men and 3 women ranging from 15 to 46 years of age. The most frequently observed symptoms were neuro-ophthalmic, followed by bruit and headache. All lesions were single fistula and fed exclusively by meningeal artery. The accessory meningeal artery was involved most often (n = 7), followed by the middle meningeal artery (n = 4). Venous drains were the ophthalmic vein (n = 11) and/or inferior petrous sinus (n = 8). No cortical vein drainage was observed. Liquid adhesives (60%) were used to obliterate all fistulas; 2 patients were also treated with detachable coils. RESULTS: All fistulas were totally occluded with resolutive fistula-related symptoms. Asymptomatic migration of liquid adhesives into the nearby arterial branch was observed in 1 patient. One patient had partial ocular choroidal infarction. No recurrent or residual fistula was found upon clinical follow-up. CONCLUSIONS: Angioarchitecture and treatment of traumatic indirect CCFs differed from the spontaneous type of fistulas. By transarterial liquid adhesive embolization, treatment of all fistulas was safe, with effective occlusion and associated low peri-procedural risk. This procedure may be considered as the primary treatment for these traumatic fistulas.

Role of CT and endovascular embolization in managing pseudoaneurysms of the internal maxillary artery.

BACKGROUND: The purpose of this study was to evaluate the role of computed tomography (CT) and endovascular embolization in managing 10 patients with 11 internal maxillary arterial pseudoaneurysms (IMPAs) with acute oronasal hemorrhage. METHODS: A series of 10 patients with 11 IMPAs presenting with profuse oronasal hemorrhage, all treated with endovascular embolization, were reviewed. There were 9 males and 1 female ranging in age from 10 to 56 years (mean, 38 years). The predisposing factors of IMPA were trauma (n = 6) or head and neck carcinomas (HNCs) after surgical treatment and/ or postradiation therapy (n = 5). Before embolization, all patients had CT of maxillofacial regions to evaluate the extension of trauma or to evaluate the treatment outcome for HNCs. Endovascular embolization was employed-to occlude the IMPAs by delivering the embolic agents of liquid adhesives (n = 9) or microcoils (n = 2) to the IMPAs. RESULTS: On the lesion side, CT revealed maxillofacial fractures in all 5 trauma patients and recurrent or residual tumors in 3 patients with HNCs. In the other 2 patients with HNCs, CT showed no significant finding and contributed little to the catheter angiography in detecting the IMPAs. Endovascular treatment was technically successful in all 11 IMPAs, ceasing hemorrhage immediately after embolization. No recurrence of bleeding was observed. No patient developed neurologic deficit, skin, or mucosal necrosis at the maxillofacial region. Clinical follow-up was 2-36 months (mean, 14 months). Two patients with advanced carcinoma died during follow-up because of disease progression. CONCLUSION: CT is a useful tool for guiding catheter angiography to localize the majority of IMPAs. Endovascular embolization can succeed in managing IMPAs, and should be performed as soon as the IMPA is depicted.

Kyphosis correction and height restoration effects of percutaneous vertebroplasty.

BACKGROUND AND PURPOSE: Percutaneous vertebroplasty is known for its pain-relieving effect. Our purpose was to evaluate its effect on the kyphosis angle, wedge angle, and height of the fractured vertebral body. METHODS: We reviewed digital radiographs of 73 vertebral bodies in 53 patients before and after vertebroplasty. We measured the spinal kyphosis angle and the wedge angle of the fractured vertebral body. Ratios of the height of the anterior border, center, and posterior borders of the collapsed vertebra to the height at the posterior border of an adjacent normal vertebral body were measured. Gain from vertebroplasty and the restoration percentage (gain divided by loss) were calculated for each parameter. RESULTS: The kyphosis angle, wedge angle, anterior height, center height, and posterior height significantly improved after vertebroplasty. The mean reduction in the kyphosis angle was 4.3 degrees, and the wedge-angle reduction was 7.4 degrees. The mean wedge-angle reduction in fractured vertebral bodies containing gas was 10.2 degrees. Restoration percentages for the kyphosis angle and wedge angle were 19% and 44%, respectively. Gain in the height of the fractured vertebral bodies was 16.7% for the anterior border, 14% for the center, and 7% for the posterior border. Restoration percentages for the height of the vertebral body were 29% for the anterior border and 27% for the center. CONCLUSION: Vertebroplasty increases the height of the fractured vertebra and reduces the wedge and kyphosis angles. These effects are most remarkable in fractured vertebra containing gas.

[Investigation of accuracy of premolar length measured by cone beam CT in vivo].

OBJECTIVE: To investigate the feasibility and accuracy of length measurement of in vivo teeth by using cone beam CT (CBCT). METHODS: Before orthodontic extraction, 109 vital premolars from 40 participants were scanned by using CBCT and reconstructed by using InVivoDental software. Buccal-lingual sectional images along the long axis of teeth were then acquired, and the crown, root, and tooth length were measured separately. After careful extraction and fixation, the corresponding length of the same tooth was measured by using a digital caliper. CBCT measurement accuracy was then verified by using physical measurements as reference. RESULTS: CBCT and the physical method did not obtain significantly different measurements of the root, crown, and tooth length of experimental teeth (P=0.790, P=0.621, P=0.657, respectively), and the measurements were found to be consistent. The 95% limits of agreement of root, crown, and tooth length were -1.10 mm to 1.13 mm, -1.00 mm to 0.96 mm, and -1.00 mm to 1.05 mm, respectively. CONCLUSION: The difference between CBCT and the physical method was not significant, and good consistency was shown. CBCT could be applied in noninvasive measurement of in vivo teeth.

Transarterial Onyx embolization of intracranial dural arteriovenous fistulas: a single center experience.

BACKGROUND: Transarterial embolization of intracranial dural arteriovenous fistulas (DAVFs) is usually associated with inadequate embolization. The purpose of this study was to report our experience of transarterial Onyx embolization of intracranial DAVFs with an emphasis on treatment outcome with this new embolic agent in different types of DAVFs. METHODS: In the past 3 years, a total of 14 intracranial DAVFs have been treated by transarterial Onyx embolization. Among these, there were nine males and five females, aged from 30 years to 82 years (mean = 62 years). We retrospectively analyzed the injection volume and time of Onyx embolization as well as outcomes in different types of DAVFs. RESULTS: The locations of the DAVFs were sigmoid sinus (n = 6), tentorium (n = 3), sinus confluence (n = 2), transverse-sigmoid sinus (n = 1), sigmoid sinus-jugular bulb (n = 1) and the superior petrous sinus (n = 1). The mean volume and time of Onyx injection were 3.4 mL and 28 minutes, respectively (Cognard type I: 4.9 mL, 40 minutes; type II: 4.5 mL, 34 minutes; type III: 2.2 mL, 21 minutes; type IV: 2 mL, 22 minutes). Total fistula occlusion was achieved in six out of seven patients of type III and type IV DAVFs, and in four out of seven patients of type I and type II DAVFs. Nine patients had total resolution of their symptoms, whereas partial regression occurred in five patients. No significant periprocedural complication was found. Mean clinical follow-up period was 16 months. CONCLUSION: Transarterial Onyx embolization of intracranial DAVFs is safe and effective. This technique is particularly useful in type III and type IV DAVFs with a high cure rate, and lower volume of Onyx as well as a short injection time.

Unusual giant intraspinal teratoma in an infant.

There are few cases of giant pediatric intraspinal teratoma. We report a case of a 4-month-old female baby with giant intraspinal teratoma. Magnetic resonance imaging (MRI) of the spine revealed a large intradural tumor from the C7 to S2 level, with solid, cystic, and fatty components. Partial surgical removal of the tumor showed pathology of a mature cystic teratoma. The imaging diagnosis of intraspinal teratoma included the location, solid and cystic component, and fatty content. The MR techniques adopted included gradient echo sequences as used to detect teeth or calcification. The difficulties in surgical resection of this case are also presented.

Risk of post-vertebroplasty fracture in adjacent vertebral bodies appears correlated with the morphologic extent of bone cement.

BACKGROUND: New fractures in adjacent vertebral bodies were found after percutaneous vertebroplasty. We evaluated the correlation between extent of polymethylmethacrylate cement and occurrence of post-vertebroplasty fractures in patients with osteoporosis. METHODS: Totally 162 adjacent vertebral bodies with no fracture at the time of vertebroplasty and the distribution of cement in corresponding treated vertebral bodies of 98 patients were included for the evaluation. Length of follow-up after vertebroplasty was 734 ± 314 days (range, 366-1838 days). Based on proximity of bone cement to the adjacent vertebral body, cement extent was classified as disc level (the closest), endplate level, or trabecula level (the farthest). RESULTS: Forty-one adjacent vertebrae had post-vertebroplasty fracture occurring 2-1038 days after vertebroplasty. The percentages of adjacent vertebral bodies having post-vertebroplasty fracture about cement extent were: disc level, 44; endplate level, 29; and trabecula level, 7. CONCLUSION: Our study revealed that the risk of subsequent fracture in the adjacent vertebral bodies was correlated with the extent of bone cement after vertebroplasty. Preventive measures can be taken from this observation to reduce the percentage of post-vertebroplasty fracture in adjacent vertebral bodies.

[Clinical application of decalcified dentinal matrix of human to repair alveolar cleft].

OBJECTIVE: To study a new method of alveolar cleft bone graft repair. METHODS: From April 2005 to August 2006, 26 cases (30 sides) of alveolar cleft were treated with trabecular substance of self-ilium combined with the decalcified dentinal matrix of human (DDM). There were 16 males and 10 females, aged 6-12 years. Unilateral alveolar cleft was involved in 22 cases, bilateral alveolar cleft in 4 cases. All cases were accompanied by nasal wing collapse, 5 by deciduous tooth retention, 3 by malposed teeth and 1 by tooth deformity. Anterior occlusal radiographs and panoramic oral radiographs were taken to observe union and bone absorption before and after operation. RESULTS: Twenty-three patients achieved healing by first intention, oronasal fistulas were closed successfully. Infection occurred in one bilateral alveolar cleft case and bone tissue exposure in 2 cases. Wound healed by rinse or dressing change and inunction with MEBO. The X-ray films after operation showed bone bridge formation in the alveolar cleft. The stability and continuity of body of maxilla were resumed. Four cases (6-9 years old) were observed 6.5 months, 22 cases (9-12 years old) were observed 8.6 months. According to Bergland for evaluation, the X-ray films after 3 months of operation showed 16 cases (16 sides) in class I (53.3%), 7 cases (8 sides) in class II (26.7%), 2 cases (4 sides) in class III (13.3%), and 1 case (2 sides) in class IV (6.7%). The overall survival ratio of alveolar bone grafting was 93.3%, and the clinical success ratio was 80%. CONCLUSION: The DDM is good in alveolar cleft bone graft repair. It is better than using self-ilium only clinically.

Patients with head and neck cancers and associated postirradiated carotid blowout syndrome: endovascular therapeutic methods and outcomes.

PURPOSE: This study retrospectively evaluated the technical and hemostatic outcomes of reconstructive and deconstructive endovascular management in patients with head and neck cancers associated with carotid blowout syndrome (CBS). METHODS: Twenty-four patients with head and neck cancers with CBS involving the main trunk of carotid artery underwent endovascular therapy. This included reconstructive management with self-expandable stent grafts to preserve the diseased carotid artery in 11 patients and deconstructive management with balloons, coils, or acrylic adhesives to occlude the diseased carotid artery in 13 patients. Based on clinical severity and therapeutic priority, we classified CBS in our patients into two groups: acute or impending and threatened. The angiographic severity was graded from 0 to 3. Evaluation of technical outcome included technical success, initial and delayed complications, and patency of stent graft in the reconstructive group. The hemostatic outcome was evaluated by immediate hemostatic result, rebleeding, and duration of hemostasis. Sex, age, clinical and angiographic severities, local wound complications, and location of the pathologic lesion were examined as predictors of the technical and hemostatic outcomes of endovascular management by using Cox regression method. RESULTS: Technical success and immediate hemostasis were achieved in all patients of both groups. Initial complications during the procedures were encountered in four patients (36.4%) who underwent reconstructive management and in one patient (7.7%) who underwent deconstructive management (P = .142). Delayed complications during the follow-up were seen in one patient (9.1%) with reconstructive management and one patient (7.7%) with deconstructive management (P > .99). Rebleeding occurred in five patients (45.5%) in the reconstructive management group and in three patients (23.1%) in the deconstructive management group (P = .659). The mean duration of hemostasis after initial reconstructive and deconstructive management was 4.0 +/- 8.1 and 8.5 +/- 10.1 months, respectively (P = .249). Rebleeding was noted in 7 of 11 patients (63.6%) with acute CBS and in 1 of 13 patients (7.7%) with impending and threatened CBS (P = .008). CONCLUSION: There is no significant difference in technical and hemostatic outcomes between the reconstructive and deconstructive endovascular management methods. Hemostatic results were influenced by clinical severity. The rebleeding rate is higher in patients with advanced and acute clinical severity.

New ligand coupling procedure for formation of an immunoadsorption wall.

To prevent the occurrence of dialysis-related amyloidosis, an immunoadsorption wall based on polyacrylamide has been manufactured by a recently developed, partially incomplete, two-stage polymerization method. During the preparation process, efficient utilization of coupling antibodies is the key to large-scale production of such a toxin removal modality. In this study, we attempted to carry out the ligand coupling procedure after formation of a cyanogen bromide (CNBr)-activated stationary phase, using anti-beta2-microglobulin (beta-2M) antibodies. In vitro immunoadsorption tests show that the levels of beta-2M decrease rapidly within the first 2 hours for all the immunoadsorption tests. After that, nearly blank values were reached for tests of initial levels of c. 30 microg/mL and c. 82 microg/mL, whereas a relatively constant level of c. 10 microg/mL was maintained for the test of initial levels of c. 185 microg/mL. The maximum surface binding capacity of the prepared immunoadsorption walls is estimated by fitting experimental data, using a mathematical model of saturation kinetics. The present comparative investigation also suggests the manufacturing process for an immunoadsorption wall could be improved and facilitated by this new ligand coupling procedure without compromising the resulting binding capacity. Furthermore, the experimental protocols as well as the present methodology could be helpful for development of a clinically applicable immunoadsorption wall.

Transarterial embolization of acute external carotid blowout syndrome with profuse oronasal bleeding by N-butyl-cyanoacrylate.

OBJECTIVES: Assess duration, efficacy, and safety of emergent transarterial embolization of acute external carotid blowout syndrome (ECBS) with N-butyl-cyanoacrylate. METHODS: Medical records were reviewed for 16 patients (15 men, 1 woman; age range, 28-85 years) who had 17 acute ECBS events that presented with profuse transoronasal bleeding. Predisposing factors were carcinoma associated with surgery and/or radiotherapy (n = 14) or trauma (n = 3). Affected arteries were the internal maxillary artery (n = 5), superior thyroid artery (n = 4), lingual artery (n = 4), facial artery (n = 2), or ascending pharyngeal artery (n = 2). RESULTS: Endovascular treatment successfully obliterated all acute ECBSs with cessation of profuse hemorrhage. Mean duration of procedure was 54 minutes. Three patients had recurrent carotid blowout syndrome events, with 1 resulting death. Clinical follow-up range was 2 to 23 months. CONCLUSIONS: Transarterial N-butyl-cyanoacrylate embolization can successfully manage acute ECBS with profuse hemorrhage. The technique is both efficient and safe, and the procedure can be rapidly completed.

Endovascular embolization of recurrent traumatic carotid-cavernous fistulas managed previously with detachable balloons.

BACKGROUND: This study investigated the causes of recurrent traumatic carotid-cavernous fistulas (RTCCFs) after detachable balloon embolization and evaluated the selection of embolic materials for endovascular treatment of the RTCCFs. METHODS: Over a 10-year period, 116 patients underwent transarterial balloon embolization with occlusion of the fistulas and preservation of the parent arteries. In 15 patients, 18 RTCCFs developed. The causes of RTCCFs included premature balloon deflation and migration (n = 13) or bony fragment puncture of balloons (n = 5). A second or third embolization involved balloons (n = 6), balloons with coils (n = 2), and N-butyl-2-cyanoacrylate with coils (n = 7), or balloon, coils, and N-butyl-2-cyanoacrylate (n = 3). RESULTS: In this study, 17 RTCCFs were successfully occluded after repeat embolization with preservation of parent arteries. One case resulted in recurrent epistaxis. The recurrent fistula and parent artery were occluded with balloons. No significant complications or recurrent fistulas occurred after the last embolization (mean follow-up period, 16 months). CONCLUSIONS: Balloon puncture or premature deflation and migration occasionally cause RTCCFs. Sacrifice of the parent artery rarely is needed. Transarterial embolization remains the best approach, with balloons used first, then coils, N-butyl-2-cyanoacrylate, or both.