Percutaneous Endoscopic Lumbar Discectomy via Transforaminal Approach Combined with Interlaminar Approach for L4/5 and L5/S1 Two-Level Disc Herniation.

OBJECTIVE: The purpose of the present study was to discuss a new surgical strategy that combines percutaneous endoscopic transforaminal discectomy (PETD) with percutaneous endoscopic interlaminar discectomy (PEID) for L4/5 and L5/S1 two-level disc herniation. METHODS: This was a retrospective study. A total of 19 patients with L4/5 and L5/S1 two-level lumbar disc herniation (LDH) who underwent percutaneous endoscopic lumbar discectomy (PELD) in our hospital from January 2015 to June 2016 were retrospectively examined. The average age of these 19 patients was 42.21 ± 14.88 years old, including 12 men and 7 women. One experienced surgeon who had carried out more than 3000 lumbar surgeries performed PELD for these patients. During the PELD surgery, the transforaminal approach was adopted for L4/5 level disc herniation and the interlaminar approach was adopted for L5/S1 level disc herniation. The demographic data, operation time (min), fluoroscopy times, hospital stay (days), and complications were recorded and analyzed. The visual analogue scale (VAS), Oswestry disability index (ODI) scores, and the modified MacNab criteria were used to evaluate the surgical outcomes. MRI was conducted to evaluate the radiographic improvement. RESULTS: All patients underwent PELD via the transforaminal approach combined with the interlaminar approach successfully and achieved satisfactory efficacy. The follow-up points were 3, 12, and 18 months. The average hospital stay (days) and the average follow up (months) were 3.32 ± 0.98 and 18.63 ± 3.84, respectively. The operation time and fluoroscopy times were 85.79 ± 12.90 min and 39.05 ± 4.59 times, respectively. The fluoroscopy times (frequency) for L4/5 and L5/S1 were 26.95 ± 6.41 and 12.11 ± 3.49 (t = 7.00, P < 0.05). Furthermore, there was no significant difference for fluoroscopy times between male and female patients (t = 0.89, P = 0.99). The preoperative back pain (VAS-Back) and the last follow-up VAS-Back were 5.58 ± 2.01 and 2.37 ± 1.01, respectively (t = 7.14, P < 0.05). The preoperative leg pain (VAS-Leg) and the last follow-up VAS-Leg were 7.00 ± 1.56 and 1.63 ± 1.01, respectively (t = 20.97, P < 0.05). There were significant differences between preoperative VAS-Back and the last follow-up VAS-Back in men (t = 4.61, P < 0.05) and women (t = 6.57, P < 0.05). In addition, there was significant differences between preoperative VAS-Leg and the last follow-up VAS-Leg in men (t = 13.48, P < 0.05) and women (t = 26.87, P < 0.05). There were significant differences between preoperative ODI scores (44.84 ± 10.82%) and the last follow-up ODI scores (11.12 ± 5.80%) (t = 10.92, P < 0.05). Preoperative ODI scores and the last follow-up ODI scores were significantly different for men (t = 8.80, P < 0.05) and women (t = 6.63, P < 0.05). All patients received significant pain relief and functional improvement after the surgery. Except for two cases of postoperative dysesthesia and one dural tear, no severe complications occurred. The dysesthesia symptoms of these two patients disappeared within 1 week with the application of dexamethasone and neurotrophic drugs and the dural tear case also recovered well as the dural laceration was small. No poor results were reported and 89.47% of patients achieved excellent or good recovery. CONCLUSION: Percutaneous endoscopic lumbar discectomy via the transforaminal approach combined with the interlaminar approach under epidural anesthesia can treat L4/5 and L5/S1 two-level disc herniation safely and effectively.

Epidural Spinal Cord Stimulation Promotes Motor Functional Recovery by Enhancing Oligodendrocyte Survival and Differentiation and by Protecting Myelin after Spinal Cord Injury in Rats.

Epidural spinal cord stimulation (ESCS) markedly improves motor and sensory function after spinal cord injury (SCI), but the underlying mechanisms are unclear. Here, we investigated whether ESCS affects oligodendrocyte differentiation and its cellular and molecular mechanisms in rats with SCI. ESCS improved hindlimb motor function at 7 days, 14 days, 21 days, and 28 days after SCI. ESCS also significantly increased the myelinated area at 28 days, and reduced the number of apoptotic cells in the spinal white matter at 7 days. SCI decreased the expression of 2',3'-cyclic-nucleotide 3'-phosphodiesterase (CNPase, an oligodendrocyte marker) at 7 days and that of myelin basic protein at 28 days. ESCS significantly upregulated these markers and increased the percentage of Sox2/CNPase/DAPI-positive cells (newly differentiated oligodendrocytes) at 7 days. Recombinant human bone morphogenetic protein 4 (rhBMP4) markedly downregulated these factors after ESCS. Furthermore, ESCS significantly decreased BMP4 and p-Smad1/5/9 expression after SCI, and rhBMP4 reduced this effect of ESCS. These findings indicate that ESCS enhances the survival and differentiation of oligodendrocytes, protects myelin, and promotes motor functional recovery by inhibiting the BMP4-Smad1/5/9 signaling pathway after SCI.

Clinical Outcome and Postoperative CT Measurements of Microendoscopic Decompression for Lumbar Spinal Stenosis.

STUDY DESIGN: This was a retrospective case series. OBJECTIVE: To retrospectively evaluate the clinical outcome of microendoscopic decompression for lumbar spinal stenosis (LSS) including an evaluation of the extent of decompression using computed tomography. SUMMARY OF BACKGROUND DATA: Microendoscopic decompression has been a widely applied procedure to treat LSS with satisfactory outcomes and comparatively fewer complications and revision. However, few reports showed computed tomography (CT) measurements of the lumbar spine to assess the postoperative decompression. METHODS: This study included 103 patients (55 males and 48 females; mean age, 69 y) who underwent microendoscopic decompression for treatment of LSS between January 2009 and January 2011. All patients underwent preoperative CT and postoperative CT at 6 months and 2 years of follow-up to measure the vertebral canal area and the sagittal diameter of the lateral recess at the outer rim. The Japanese Orthopedic Association (JOA) scale, Oswestry Disability Index, and Visual Analogue Scale were used to evaluate clinical efficacy. RESULTS: The mean vertebral canal area and sagittal diameter of the lateral recess were significantly larger at 6 months and 2 years after surgery compared with 1 day before surgery (P<0.001). The mean JOA scale scores were significantly higher at 6 and 24 months following surgery compared with before surgery (P<0.001). The mean Oswestry Disability Index scores and Visual Analogue Scale scores at 6 months and 2 years after surgery were significantly lower compared with before surgery (both P<0.001). The mean JOA recovery rates at 6 months and 2 years of follow-up were 61% and 64.3%, respectively. CONCLUSIONS: The results confirm that microendoscopic decompression for LSS is safe and effective. This study is one of the first to obtain CT measurements of the lumbar spine to assess the postoperative decompression of this procedure.

Investigation of the relationship between chromobox homolog 8 and nucleus pulposus cells degeneration in rat intervertebral disc.

Here, we aimed to investigate the expression of chromobox homolog 8 (CBX8) in nucleus pulposus (NP) cells from rat intervertebral disc (IVD) and its function in DNA damage and repair. NP cells were isolated from healthy rat IVD for immunohistochemistry staining. Small interfering RNA (siRNA) of CBX8 was applied for gene silencing, and reverse transcriptase-polymerase chain reaction (RT-PCR) was performed to determine mRNA levels of CBX8, type II collagen, and proteoglycans. Cell proliferation and cell cycle were evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, colony-forming assay, and flow cytometry. Hydrogen peroxide (H2O2) was added to simulate DNA oxidative damage, and expression of CBX8 was examined using RT-PCR and Western blot. After five passages, mRNA levels of type II collagen and proteoglycans decreased but that of CBX8 increased. When CBX8 was silenced by siRNA, the expressions of CBX8, type II collagen and proteoglycans declined, and the cell growth was inhibited. Besides, cell cycle was slowed down as most cells were arrest in G0/G1 phase. Furthermore, CBX8 expression went up responding to DNA oxidative damage caused by H2O2. The data indicated that CBX8 plays important roles in cell proliferation and DNA damage. Cell proliferation and cell cycle were stimulated by CBX8, which may be associated with INK4A-ARF pathway. Moreover, CBX8 plays a role in DNA damage which made it a potential gene therapy target for treatment of disc degeneration.

Magnetic resonance imaging analysis of surgical trans-sacral axial L5/S1 interbody fusion.

BACKGROUND: Trans-sacral axial L5/S1 interbody fusion (AxiaLIF), a novel surgical procedure, recently adopted in clinical practice, has excellent clinical outcomes. However, there is inadequate data on the feasibility of the approach in all adult patients and the optimal surgical approach is currently unclear; therefore, further studies are required. In order to enhance the surgical approach for AxiaLIF, prospective anatomical imaging optimization is necessary. The objective of this study was to investigate the ability of magnetic resonance imaging (MRI) to achieve an optimal procedural setting. METHODS: The subjects (n=40) underwent lumbosacral MRI examination. The median sagittal MRI images were analyzed and four measurement markers were defined as follows: the center of the L5/S1 disc (A), the anterior margin of the S1/2 disc space (B), the sacrococcygeal junction (C), and the coccygeal tip (D). The measurement markers were connected to each other to produce five lines (AB, AC, AD, BC, and BD), as reference lines for surgical approaches. The distance between each reference line and the anterior and posterior margins of the L5 and S1 vertebral bodies was measured to determine the safety of the respective approaches. RESULTS: In all patients, Lines AB and AC satisfied the imaging safety criteria. Line AB would result in a significant deviation from the median and was determined to be unsuitable for AxiaLIF. Line AD satisfied the imaging safety criteria in 39 patients. However, the anal proximity of the puncture point proved to be limiting. For lines BC and BD, the imaging safety criteria were satisfied in 70% and 45% of patients, respectively. CONCLUSIONS: The AxiaLIF procedure is a safe technique for insertion of fusion implants in all subjects. Line AC is a favorable reference line for surgical approach and safe for all subjects, while line BC is not suitable for all subjects.

[The clinical results of minimally invasive transforaminal lumbar interbody fusion for lumbar spinal stenosis with lumbar instability].

OBJECTIVE: To investigate the clinical results of minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) for lumbar spinal stenosis with lumbar instability. METHODS: Retrospective study was done on 42 cases of lumbar spinal stenosis with lumbar instability treated with bilateral decompression via unilateral approach and MIS-TLIF through an expandable tubular retractor from March 2010 to January 2011. There were 18 males and 24 females, and mean age was 61.7 years (rang, 48 - 79 years). The level of surgery was L(3-4) in 4 patients, L(4-5) in 26 patients, and L(5)-S(1) in 12 patients. All patients had symptoms of intermittent claudication. And 24 patients had symptoms of lower extremity pain and numbness in one side, and 18 patients had same symptoms in both legs. Operation time, intra-operative bleeding, postoperative hospital stay and complications were recorded. Visual analogue scale (VAS) scores for low back pain and leg pain were recorded before and after surgery. Oswestry disability index (ODI) scores were also recorded before and after surgery. The Bridwell criterion was used for evaluating the interbody fusion, and the MacNab criterion was used for assessment after surgery. RESULTS: The mean operative time was 150.4 minutes (range, 120 - 170 minutes), and mean blood loss was 147.1 ml (range, 50 - 400 ml). The hospitalization time after surgery was 5 - 18 d, an average of 8.8 d. All cases were followed-up for 6 - 14 months (average 11 months). VAS score of low back pain before surgery was 7.3 ± 1.0, and were 2.9 ± 0.8 and 2.0 ± 0.8 at three months after surgery and the last follow-up respectively. VAS score of leg pain before surgery was 7.9 ± 0.7, and were 2.0 ± 0.5 and 1.0 ± 0.7 at three months after surgery and the last follow-up respectively. ODI score was 75% ± 6% before surgery, were 16% ± 6% and 12% ± 5% at three months after surgery and the last follow-up respectively. VAS and ODI scores showed statistically significant improvements (t = 3.110 - 56.323, P < 0.01). There were 40 cases were grade I and II, according to the Bridwell criteria. The clinical results were excellent in 16 cases, good in 22 cases and fair in 4 cases to the MacNab criteria at the final follow-up. CONCLUSIONS: MIS-TLIF is an ideal surgical method for single segment lumbar spinal stenosis with lumbar instability, but close attention should be paid to specific patients, surgeons and hospitals.