Autologous Mesenchymal Stromal Cells Combined with Gelatin Sponge for Repair Intervertebral Disc Defect after Discectomy: A Preclinical Study in a Goat Model.

BACKGROUND: The defect of intervertebral disc (IVD) after discectomy may impair tissue healing and predispose patients to subsequent IVD degeneration, which is thought to be an important cause of recurrence. Cell-based approaches for the treatment of IVD degeneration have shown promise in preclinical studies. However, most of these therapies have not been approved for clinical use due to the risks of abnormal differentiation and microorganism contamination of the culture-expanded cells. Selective cell retention (SCR) technology is non-cultivation technique, which can avoid those preambles in cell expansion. In this study, we used a commercially available BONE GROWTH PROMOTER device (BGP, FUWOSI, Chongqing, China) to concentrate mesenchymal stromal cells (MSCs) from bone marrow aspirate (BMA) through SCR technology. METHODS: A small incision was made on the L2/3, L3/4 and L4/5 discs of goats and part of nucleus pulposus (NP) was removed to construct IVD defect model. The L2/3 disc was subjected to discectomy only (DO group), the L3/4 disc was implanted with enriched BMA-matrix (CE group), and the L4/5 disc was implanted cultured autologous bone marrow MSCs matrix (CC group). And the intact L1/2 disc served as a non-injured control (NC group). The animals were followed up for 24 weeks after operation. Spine imaging was analysis performed at 4 and 24 weeks. Histology, immunohistochemistry, gene expression and biomechanical analysis were performed to investigate the IVD morphology, content and mechanical properties at 24 weeks. RESULTS: The CE and CC groups showed a significantly smaller reduction in the disc height and T2-weighted signal intensity, and a better spinal segmental stability than DO group. Histological analysis demonstrated that CE and CC groups maintained a relatively well-preserved structure compared to the DO group. Furthermore, real-time PCR and immunohistochemistry demonstrated that aggrecan and type II collagen were up-regulated in CE and CC groups compared to DO group. CONCLUSIONS: The strategy of MSCs enrichment combined with gelatin sponge by SCR technology provides a rapid, simple, and effective method for cell concentration and cell-carrier combination. This reparative strategy can be used in clinical treatment of IVD defect after discectomy. CLINICAL TRIAL REGISTRATION: NCT03002207.

Selective Retention of Bone Marrow Stromal Cells with Gelatin Sponge for Repair of Intervertebral Disc Defects after Microendoscopic Discectomy: A Prospective Controlled Study and 2-Year Follow-Up.

OBJECTIVE: Discectomy remains the classic procedure for treating lumbar intervertebral disc (IVD) herniation, but the occurrence of defects after discectomy is thought to be an important cause generating recurrent and accelerated IVD degeneration. Previous studies attempted suture of the annulus fissure, but the validity of this technique on restraining the degenerative process is controversial. On the other hand, cell therapies have been shown in multiple clinical and basic studies. Our purpose was to investigate the effectiveness of selective retention of autologous Bone Marrow Stromal Cells (BMSCs) with gelatin sponge in combination with annulus fibrosus suture (AFS) for the repair of IVD defects following mobile microendoscopic discectomy (MMED). METHODS: This prospective, two-armed, and controlled clinical study was conducted from December 2016 to December 2018. Written informed consent was obtained from each patient. Forty-five patients with typical symptoms, positive signs of radiculopathy, and obvious lumbar disc herniation observed by MRI were enrolled. Patients were divided into 3 groups with different treating methods: MMED (n = 15), MMED+AFS (n = 15), and MMED+AFS+BMSCs (n = 15). A postoperative 2-year follow-up was performed to evaluate the patient-reported outcomes of VAS, ODI, and SF-36. The improvement rate of VAS and ODI was calculated as [(latest-preoperative)/preoperative] to evaluate the therapeutic effect of the three groups. Assessment parameters included Pfirrmann grade, intervertebral disc height (IDH), and disc protrusion size (DPS), as measured by MRI to evaluate the morphological changes. RESULTS: All patients enrolled had a postoperative follow-up at 3, 6, 12, and 24 months. VAS and ODI scores were significantly improved compared to the preoperative status in all three groups with a mean DPS reduction rate over 50%. At the final follow-up, the improvement rate of the VAS score in the MMED+AFS+BMSCs group was significantly higher than the MMED+AFS and MMED groups (80.1% ± 7.6% vs. 71.3% ± 7.0% vs. 70.1% ± 7.8%), while ODI improvement showed a significant change (65.6% ± 8.8% vs. 59.9% ± 5.5% vs. 57.8% ± 8.1%). All participants showed significant improvement in SF-36 PCS and MCS; the differences between each group were not significant. The mean IDH loss rate of the MMED+AFS+BMSCs group was also significantly lower than other groups (-17.2% ± 1.3% vs. -27.6% ± 0.7% vs. -29.3% ± 2.2%). The Pfirrmann grade was aggravated in the MMED and MMED+AFS groups while maintained at the preoperative grade in the MMED+AFS+BMSCs group. No adverse events of cell transplantation or recurrence were found in all patients during the postoperative follow-up period. CONCLUSIONS: It is feasible and effective to repair lumbar IVD defects using SCR-enriched BMSCs with gelatin sponges, which warrants further study and development as a cell-based therapy for IVD repair.

Efficacy and safety of tranexamic acid in reducing blood loss in scoliosis surgery: a systematic review and meta-analysis.

OBJECTIVE: The purpose of this systematic review and meta-analysis of randomized controlled trials (RCTs) and non-RCTs was to gather data to evaluate the efficacy and safety of tranexamic acid (TXA) versus placebo after a scoliosis surgery. METHODS: The electronic databases including Embase, PubMed, CENTRAL (Cochrane Controlled Trials Register), Web of Science, and Google database were searched to identify relevant studies published from the time of the establishment of these databases up to May 2016. This systematic review and meta-analysis was performed according to the PRISMA statement criteria. The primary outcomes were total blood loss, intraoperative blood loss, and hemoglobin after surgery. The second outcome is need for transfusion. Stata 12.0 software was used for the meta-analysis. After testing for publication bias and heterogeneity across studies, data were aggregated for random-effects modeling when necessary. RESULTS: A total of 685 patients (347 patients in the TXA group and 338 in the control group) were finally included for this meta-analysis. The pooled results revealed that administration of TXA can decrease the total blood loss after scoliosis surgery [mean difference (MD) = 682.30, 95% confidence interval (CI) -930.60 to -434.00; P = 0.000] and intraoperative blood loss [(MD) = -535.28; 95% CI -683.74 to -368.82; P = 0.000]. For the hemoglobin (Hb) value after scoliosis surgery, TXA can decrease the Hb value for 0.51 dL [(MD) = 0.51; 95% CI 0.25-0.78; P = 0.000]. There is no statistically significant difference between the TXA versus placebo in terms of the need for transfusion (relative risk = 0.55, 95% CI 0.25-1.20, P = 0.132). CONCLUSION: Based on the current meta-analysis, TXA can decrease the total blood loss and intraoperative blood loss during scoliosis surgery. It is recommended that it be routinely used in scoliosis surgery. High-dose TXA (>20 mg/kg) is more effective than low-dose TXA (<20 mg/kg) in controlling blood loss. However, for the need for transfusion, more high-quality RCTs need to be identified.

Thoracic Endoscopic-Assisted Mini-Open Surgery for Thoracic and Thoracolumbar Spinal Cord Compression.

Intervertebral disc herniation is a common cause of spinal cord compression, especially for the thoracic and thoracolumbar spinal cord, which has limited buffer space in the spinal canal. Spinal cord compression usually causes decreased sensation and paralysis of limbs below the level of compression, urinary and fecal incontinence, and/or urinary retention, which brings great suffering to the patients and usually requires surgical intervention. Thoracotomy or abdominothoracic surgery is usually performed for the thoracolumbar cord compression caused by hard intervertebral disc herniation. However, there is high risk of trauma and complications with this surgery. To reduce the surgical trauma and obtain good visibility, we designed athoracic endoscopic-assisted mini-open surgery for thoracic and thoracolumbar disc herniation, and performed this procedure on 10 patients who suffered from hard thoracic or thoracolumbar spinal cord compression. During the procedure, the thoracic endoscopy provided clear vision of the surgical field with a good light source. The compression could be fully exposed and completely removed, and no nerve root injury or spinal cord damage occurred. All patients achieved obvious recovery of neurological function after this procedure. This technique possesses the merits of minimal trauma, increased safety, and good clinical results. The aim of this study is to introduce this thoracic endoscopic-assisted mini-open surgery technique, and we believe that this technique will be a good choice for the thoracic and thoracolumbar cord compression caused by hard intervertebral disc herniation.