ObjectiveTo review the definition and possible etiologies for C5 palsy. MethodsThe literature on C5 palsy at home and abroad in recent years was extensively reviewed, and the possible etiologies were analyzed based on clinical practice experience. ResultsThere are two main theories (nerve root tether and spinal cord injury) accounting for the occurrence of C5 palsy, but both have certain limitations. The former can not explain the occurrence of C5 palsy after anterior cervical spine surgery, and the latter can not explain that the clinical symptoms of C5 palsy is often the motor dysfunction of the upper limb muscles. Based on the previous reports, combining our clinical experience and research, we propose that the occurrence of C5 palsy is mainly due to the instrumental injury of anterior horn of cervical spinal cord during anterior cervical decompression. In addition, the C5 palsy following surgery via posterior approach may be related to the nerve root tether caused by the spinal cord drift after decompression. ConclusionIn view of the main cause of C5 palsy after cervical decompression, it is recommended to reduce the compression of the spinal cord by surgical instruments to reduce the risk of this complication.
Objective To manufacture fish swim bladder membrane material by crosslinking techniques, and to explore its physical and chemical properties and cytotoxicity. Methods After decellularization, the swim bladders were randomly divided into two groups. The swim bladders were treated with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC)/N-hydroxysuccinimide (NHS) crosslinking method, surface hole making, and freeze-drying in crosslinking group, and only surface hole making and freeze-drying in non-crosslinking group. The physical and chemical properties of the materials were observed, including microstructure by scanning electron microscopy (SEM), mechanical properties (tensile strength and breaking elongation) by universal tensile machine, hydrophilicity by contact angle measuring instrument, porosity by ethanol infiltration method, degradation performance in vitro and thermal stability test, and the components of materials by infrared spectrum analysis. Mouse fibroblasts (L929) were cultured with the extracts of two groups of materials in order to determine the cytotoxicity of materials by using cell counting kit 8 (CCK-8) method. Results The porous structure and rough surface of materials were observed by SEM. Compared with the non-crosslinking group, the tensile stress of the crosslinking group was higher, the breaking elongation was lower, and the porosity increased, showing significant differences (P<0.05). There was no significant difference in contact angle between the two groups (P>0.05). The degradation was faster within the first 7 days and then tended to be smooth in the two groups. But the degradation rates of crosslinking group were significantly lower than those of non-crosslinking group (P<0.05). Differential scanning calorimeter showed that the denaturation temperature of the crosslinking group was (75.2±1.3)℃, which was significantly higher than that of the non-crosslinking group [(68.5±0.4)℃] (t=4.586, P=0.002). Compared with the non-crosslinking group, the crosslinking group produced new C=O bond and N-H bond, and no other new groups were introduced into the cross-linking group. CCK-8 method showed that the absorbance values of the crosslinking group and the non-crosslinking group were not significant when compared with the positive control group (P>0.05). Conclusion The fish swim bladder membrane obtained by crosslinking treatment with EDC/NHS method has good physical and chemical properties, no cytotoxicity, and is expected to be used as a dura mater repair material.
Objective A prospective randomized controlled trial was conducted to study the effectiveness and safety of intravenous different doses tranexamic acid (TXA) in single-level unilateral minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF). Methods The patients treated with single-level unilateral MIS-TLIF between September 2019 and October 2020 were enrolled and randomly classified into low-dose TXA (LD) group (n=39), high-dose TXA (HD) group (n=39), and placebo-controlled (PC) group (n=38). The LD, HD, and PC groups received intravenous TXA 20 mg/kg, TXA 50 mg/kg, the same volume of normal saline at 30 minute before skin incision after general anesthesia, respectively. There was no significant difference on baseline characteristics and preoperative laboratory results among 3 groups (P>0.05), including age, gender, body mass index, surgical segments, hematocrit (HCT), hemoglobin (HGB), prothrombin time (PT), international normalized ratio (INR), D-dimer, fibrin degradation products (FDP), activated partial prothromboplastin time (APTT), alanine aminotransferase (ALT), aspartate aminotransferase (AST), creatinine (Cr), urea. The intraoperative blood loss (IBL), postoperative drainage volume, operation time, total blood loss (TBL), hidden blood loss (HBL), blood transfusion, hematological examination indexes on the first day after operation, and the incidence of complications within 1 month were compared among the 3 groups. Results There were 3, 2, and 4 patients in the LD, HD, and PC groups who underwent autologous blood transfusion, respectively, and there was no allogeneic blood transfusion patients in the 3 groups. There was no significant difference in IBL, postoperative drainage volume, and operation time between groups (P>0.05). The TBL, HBL, and the decreased value of HGB in LD and HD groups were significantly lower than those in PC group (P<0.05), and TBL and HBL in HD group were significantly lower than those in LD group (P<0.05); the decreased value of HGB between LD group and HD group showed no significant difference (P>0.05). On the first day after operation, D-dimer in LD and HD groups were significantly lower than that in PC group (P<0.05); there was no significant difference between LD and HD groups (P>0.05). There was no significant difference in other hematological indexes between groups (P>0.05). All patients were followed up 1 month, and there was no TXA-related complication such as deep venous thrombosis of lower extremity, pulmonary embolism, and epilepsy in the 3 groups. ConclusionIntravenous administration of TXA in single-level unilateral MIS-TLIF is effective and safe in reducing postoperative TBL and HBL within 1 day in a dose-dependent manner. Also, TXA can reduce postoperative fibrinolysis markers and do not increase the risk of thrombotic events, including deep venous thrombosis and pulmonary embolism.
