Recent advances in lipid nanovesicles for targeted treatment of spinal cord injury.

The effective regeneration and functional restoration of damaged spinal cord tissue have been a long-standing concern in regenerative medicine. Treatment of spinal cord injury (SCI) is challenging due to the obstruction of the blood-spinal cord barrier (BSCB), the lack of targeting of drugs, and the complex pathophysiology of injury sites. Lipid nanovesicles, including cell-derived nanovesicles and synthetic lipid nanovesicles, are highly biocompatible and can penetrate BSCB, and are therefore effective delivery systems for targeted treatment of SCI. We summarize the progress of lipid nanovesicles for the targeted treatment of SCI, discuss their advantages and challenges, and provide a perspective on the application of lipid nanovesicles for SCI treatment. Although most of the lipid nanovesicle-based therapy of SCI is still in preclinical studies, this low immunogenicity, low toxicity, and highly engineerable nanovesicles will hold great promise for future spinal cord injury treatments.

3D Bioprinting for Spinal Cord Injury Repair.

Spinal cord injury (SCI) is considered to be one of the most challenging central nervous system injuries. The poor regeneration of nerve cells and the formation of scar tissue after injury make it difficult to recover the function of the nervous system. With the development of tissue engineering, three-dimensional (3D) bioprinting has attracted extensive attention because it can accurately print complex structures. At the same time, the technology of blending and printing cells and related cytokines has gradually been matured. Using this technology, complex biological scaffolds with accurate cell localization can be manufactured. Therefore, this technology has a certain potential in the repair of the nervous system, especially the spinal cord. So far, this review focuses on the progress of tissue engineering of the spinal cord, landmark 3D bioprinting methods, and landmark 3D bioprinting applications of the spinal cord in recent years.

Transforaminal endoscopic excision of bi-segmental non-communicating spinal extradural arachnoid cysts: A case report and literature review.

BACKGROUND: Spinal extradural arachnoid cysts (SEACs) are a rare cause of spinal cord compression. Typically, these cysts communicate with the intradural subarachnoid space through a small defect in the dural sac. For symptomatic SEACs, the standard treatment is to remove the cyst in total with a (hemi)laminectomy or laminoplasty. We present a rare case of bi-segmental non-communicating SEACs and describe our experience of using an endoscopic minimal access technique to remove bi-segmental non-communicating SEACs. CASE SUMMARY: A 79-year-old female presented with pain related to bi-segmental SEACs at the T11-L1 segments. She underwent sequential transforaminal percutaneous endoscopic thoracic cystectomy of the SEACs. Following her first procedure, spinal magnetic resonance imaging demonstrated complete excision of the cyst at the T12-L1 segment. However, the cyst at the T11-T12 segment was still present. Thus, a second procedure was performed to remove this lesion. The patient's right-sided lumbar and abdominal pain improved significantly postoperatively. Her Japanese Orthopaedic Association score increased from 11 to 25, her visual analogue scale score was reduced from 8 to 1. The physical and mental component summary of the 36-item short-form health survey (SF-36) were 15.5 and 34.375 preoperatively, and had increased to 79.75 and 77.275 at the last follow-up visit, respectively. CONCLUSION: Bi-segmental non-communicating SEACs are extremely rare. Endoscopic surgery is a safe, effective, and reliable method for treating these cysts. In the event of bi-segmental SEACs, it is important to identify whether both cysts are communicating before surgery, and if not, to remove both cysts separately during the index surgery to avoid re-operation.

Zina percutaneous screw fixation combined with endoscopic lumbar intervertebral fusion under intraoperative neuromonitoring: A case report.

INTRODUCTION: Traditional open discectomy and intervertebral fusion surgery is the common strategy for lumbar disc herniation (LDH). However, it has the disadvantages of long recovery time and severe paravertebral soft tissue injury. Zina percutaneous screw fixation combined with endoscopic lumbar intervertebral fusion (ZELIF), as a novel minimally invasive surgical technique for LDH, has the advantages in quicker recovery, less soft tissue destruction, shorter hospital stays and less pain. We report a novel technique of ZELIF under intraoperative neuromonitoring (INM) for the treatment of LDH. PATIENT CONCERNS: A 51-year-old male presented to our hospital with left lower extremity pain and numbness for 1 year. DIAGNOSIS: Lumbar disc herniation (LDH). INTERVENTIONS: This patient was treated with Zina percutaneous screw fixation combined with endoscopic neural decompression, endplate preparation, and intervertebral fusion through Kambin's triangle. Each step of the operation was performed under INM. OUTCOMES: The follow-up period lasted 12 months; the hospitalization lasted 4 nights; the blood loss volume was 65 ml, and the time of operation was 266 min. INM showed no neurological damage during the surgery. No surgical complications, including neurological deterioration, cage migration, non-union, instrumentation failure or revision operation, were observed during the follow-up period. Visual Analogue Scale (VAS) score reduced from 7 to 1; the Oswestry Disability Index (ODI) decreased from 43 to 14; the EQ-5D score was 10 preoperatively and 15 at the final follow-up visit; the Physical Component Summary of the 36-Item Short Form Health Survey (SF-36) was 48 preoperatively and 49 at the last follow up visit; the SF-36 Mental Component Summary was 47 before surgery and decreased to 41 postoperatively. CONCLUSION: ZELIF under INM may represent a feasible, safe and effective alternative to endoscopic intervertebral fusion and percutaneous screw fixation, for decompressing the lumbar's exiting nerve root directly with minimal invasion in selected patients.

Neurological deterioration as a result of improper neck position detected by intraoperative neurophysiological monitoring in a cervical stenosis patient: A case report.

RATIONALE: Intraoperative neurophysiological monitoring (IONM) is widely used in spinal surgeries to prevent iatrogenic spinal cord injury (SCI). Most surgeons focus on avoiding neurological compromise intraoperatively, while ignoring the possibility of nerve damage preoperatively, such as neck positioning. Thus, this study aims to report a case with transient neurological deterioration due to improper neck position detected by IONM during cervical surgery. PATIENT CONCERNS: A 63-year-old male patient had been suffering from hypoesthesia of the upper and lower extremities for three years. DIAGNOSES: Severe cervical stenosis (C5-C7) and cervical ossification of a posterior longitudinal ligament. INTERVENTIONS: The cervical stenosis patient underwent an anterior cervical corpectomy decompression and fusion (ACDF) surgery with the assistance of IONM. When the lesion segment was exposed, the SSEP and MEP suddenly elicited difficulty indicating that the patient may have developed SCI. All the technical causes of IONM events were eliminated, and the surgeon suspended operation immediately and suspected that the IONM alerts were caused by cervical SCI due to the improper position of the neck. Subsequently, the surgeon repositioned the neck of the patient by using a thinner shoulders pad. OUTCOMES: At the end of the operation, the MEP and SSEP signals gradually returned to 75% and 80% of the baseline, respectively. Postoperatively, the muscle strength of bilateral biceps decreased from grade IV to grade III. Besides, the sensory disturbance of both upper extremities aggravated. However, the muscle power and hypoesthesia were significantly improved after three months of neurotrophic therapy and rehabilitation training, and no complications of nerve injury were found at the last follow-up visit. LESSONS: IONM, consisting of SSEP and MEP, should be applied throughout ACDF surgery from the neck positioning to suture incisions. Besides, in the ward 1to 2 days before operation, it is necessary for conscious patients with severe cervical stenosis to simulate the intraoperative neck position. If the conscious patients present signs of nerve damage, they can adjust the neck position immediately until the neurological symptoms relieve. Therefore, intraoperatively, the unconscious patient can be placed in a neck position that was confirmed preoperatively to prevent SCI.

Comparative evaluation of posterior percutaneous endoscopy cervical discectomy using a 3.7 mm endoscope and a 6.9 mm endoscope for cervical disc herniation: a retrospective comparative cohort study.

BACKGROUND: Posterior percutaneous endoscopy cervical discectomy (p-PECD) is an effective strategy for the treatment of cervical diseases, with a working cannula ranging from 3.7 mm to 6.9 mm in diameter. However, to date, no studies have been performed to compare the clinical outcomes of the use of endoscopes with different diameters in cervical disc herniation (CDH) patients. The purpose of this study was to compare the clinical outcomes of patients with unilateral CDH treated with p-PECD using a 3.7 mm endoscope and a 6.9 mm endoscope. METHODS: From January 2016 to June 2018, a total of 28 consecutive patients with single-level CDH who received p-PECD using either the 3.7 mm or the 6.9 mm endoscope were enrolled. The clinical results, including the surgical duration, hospitalization, visual analog scale (VAS) score and modified MacNab criteria, were evaluated. Cervical fluoroscopy, CT, and MRI were also performed during follow-up. RESULTS: Tthere was a significant difference in regard to the average identification time of the "V" point (18.608 ± 3.7607 min vs. 11.256 ± 2.7161 min, p < 0.001) and the mean removal time of the overlying tissue (16.650 ± 4.1730 min vs. 12.712 ± 3.3079 min, p < 0.05) for the use of the 3.7 mm endoscope and the 6.9 mm endoscope, respectively. The postoperative VAS and MacNab scores of the two endoscopes were significantly improved compared with those the preoperative scores (p < 0.05). CONCLUSION: The application of both the 3.7 mm endoscope and 6.9 mm endoscope represent an effective method for the treatment of CDH in selected patients, and no significant difference can be observed in the clinical outcomes of the endoscopes. The 6.9 mm endoscope shows superiority to the 3.7 mm endoscope in terms of the efficiency of "V" point identification, the removal of overlying soft tissue and the prevention of spinal cord injury. However, the 6.9 mm endoscope may be inferior to the 3.7 mm endoscope in regards to anterior foraminal decompression due to its large diameter; this result needs to be further evaluated with the support of a large number of randomized controlled trials.

Selective nerve root block combined with posterior percutaneous cervical endoscopic discectomy for cervical spondylotic radiculopathy with double nerve root variation: A case report.

RATIONALE: The aim of this report is to present the technique of selective nerve root blockage combined with posterior percutaneous cervical endoscopic discectomy (PPECD) for cervical spondylotic radiculopathy (CSR). PATIENT CONCERNS: A 49-year-old female has pain in the skin area of the left scapular, pain in left elbow and limitation of left upper limb movement for 1.5 years. DIAGNOSIS: She was diagnosed with CSR and C6-7 double nerve root variation. INTERVENTIONS: We used selective nerve root block to determine the lesion segment and applied PPECD to relieve pressure on the patient's nerve roots. OUTCOMES: The pain symptoms disappeared after the patient was treated with C6-7 nerve root block. Endoscopic displayed C6-7 double nerve root variation on the left side of the spinal cord intraoperative. The neurological function was intact postoperatively and no recurrence of cervical disc herniation during the 5 months' follow-up period. The hospitalization time was 5 days, the operation time was 68.2 minutes and the bleeding volume was 52.6 ml. There was no change in cervical curvature and cervical disc height postoperatively. Japanese Orthopaedic Association score, SF-36 score and Visual Analogue Scale score improved significantly postoperatively. LESSONS: The application of selective nerve root blockage combined with PPECD for CSR could achieve satisfactory effect of position and decompression of the injured nerve root. Besides, we recommend that surgery be performed under general anesthesia to minimize patients' emotional stress and discomfort.