Seil Sohn

Less invasive palliative surgery for spinal metastases.

There may be patients with spinal metastasis for whom neither vertebroplasty/kyphoplasty nor open surgery is appropriate. Percutaneous pedicle screw fixation (PPSF) may fill the gap between techniques.

The Surgical Outcome and the Surgical Strategy of Percutaneous Endoscopic Discectomy for Recurrent Disk Herniation

Study Design: A retrospective analysis. Objective: To present the surgical outcome of percutaneous endoscopic discectomy (PED) for recurrent herniated intervertebral disk disease (HIVD) and to suggest a surgical strategy. Summary of Background Data: Revision discectomy is technically demanding because of the scar tissue, unclear anatomic planes, and retraumatization to the posterior structures. Although open microdiscectomy is a standard method, endoscopic techniques have emerged as a surgical alternative with comparable results. PED was performed with either the transforaminal (PETD) or the interlaminar approach (PEID). Previous reports have shown the surgical outcomes of PETD or PEID for recurrent HIVD, but the application of each approach was not addressed clearly. Methods: Consecutive 26 patients (M:F=16:10, mean age 53.1±12.4 y), who underwent PED for recurrent HIVD, were enrolled. The previous operation was an open discectomy in 22, a PETD in 2, and a PEID in 2 patients. PETD was considered preferentially, if it was feasible (n=11), because of the scar tissue formed by the previous operation. PEID was chosen (n=15) because of a high iliac crest (8), high canal compromise (3), high-grade inferior migration (2), and narrow neural foramen (2). All patients were followed up for 19.3±11.3 months. Results: In all patients, the recurrent disk material was removed successfully, and conversion to an open surgery was not necessary. Postoperative magnetic resonance imaging revealed that the ruptured disk was removed successfully in all cases. A favorable outcome (excellent or good outcome by MacNab’s criteria) was achieved in 21 patients (81%). Re-recurrence occurred in 2 patients at 6 and 12 months postoperatively. Risk factors for an unfavorable outcome were not found in the present study (P>0.05). Conclusions: The relevant utilization of updated surgical techniques may be helpful in overcoming the difficulty of revision surgery.

Segmental kyphosis after cervical interbody fusion with stand-alone polyetheretherketone (PEEK) cages: a comparative study on 2 different PEEK cages.

Study Design: Retrospective comparative study. Objective: Two polyetheretherketone (PEEK) cages of different designs were compared in terms of the postoperative segmental kyphosis after anterior cervical discectomy and fusion. Summary of Background Data: Segmental kyphosis occasionally occurs after the use of a stand-alone cage for anterior cervical discectomy and fusion. Although PEEK material seems to have less risk of segmental kyphosis compared with other materials, the occurrence of segmental kyphosis for PEEK cages has been reported to be from 0% to 29%. There have been a few reports that addressed the issue of PEEK cage design. Method: A total of 41 consecutive patients who underwent single-level anterior discectomy and fusion with a stand-alone cage were included. Either a round tube–type (Solis; 18 patients, S-group) or a trapezoidal tube–type (MC+; 23 patients, M-group) cage was used. The contact area between the cage and the vertebral body is larger in MC+ than in Solis, and anchoring pins were present in the Solis cage. The effect of the cage type on the segmental angle (SA) (lordosis vs. kyphosis) at postoperative month 24 was analyzed. Results: Preoperatively, segmental lordosis was present in 12/18 S-group and 16/23 M-group patients (P=0.84). The SA was more lordotic than the preoperative angle in both groups just after surgery, with no difference between groups (P=0.39). At 24 months, segmental lordosis was observed in 9/18 S-group and 20/23 M-group patients (P=0.01). The patients in M-group were 7.83 times more likely than patients in S-group (P=0.04; odds ratio, 7.83; 95% confidence interval, 1.09–56.28) not to develop segmental kyphosis. Conclusions: The design of the PEEK cage used may influence the SA, and this association needs to be considered when using stand-alone PEEK cages.

A nationwide epidemiological study of newly diagnosed spine metastasis in the adult Korean population

BACKGROUND CONTEXT Metastatic spine tumor has become clinically important because of the availability of improved diagnostic tools and increases in survival periods in cancer patients. In spite of this interest, the burden of metastatic spine tumor on the general population has not been extensively reported. PURPOSE The aim of this 2009-2011 nationwide study of adult Koreans was to describe characteristics, medical use, and survival rate of patients with newly diagnosed metastatic spine tumors according to the primary tumor. DESIGN/SETTING This is a retrospective cohort study. PATIENT SAMPLE A national health insurance database was used to identify a cohort of patients with newly diagnosed metastatic spine tumors. OUTCOME MEASURES This study aimed to analyze characteristics, medical use, and survival rate of patients with newly diagnosed metastatic spine tumors according to the primary tumor. METHODS Data for patients with metastatic spine tumors were extracted from the Korean Health Insurance Review and Assessment Service database. Data included patient age, sex, health insurance type, comorbidities, medical cost, and hospital stay duration. Hospital stay duration and medical costs per person during 1 calendar year were evaluated. In addition, survival rates of patients with metastatic spine tumor according to primary tumor sites were evaluated. RESULTS The incidence rate of spine metastasis increased with age, year of diagnosis, and the number of comorbidities (p≤.0001). The 6 most prevalent primary tumor sites were lung, liver and biliary tract, breast, colon, stomach, and prostate. Of patients with the 6 most prevalent primary tumors, total average annual medical costs, including inpatient and outpatient services, ranged from 12,734USD (prostate origin) to 15,556 USD (lung origin). Of patients with the 6 most prevalent primary tumors, total average annual hospital stay duration, including inpatient and outpatient services, ranged from 70.8 days (stomach origin) to 78.7 days (colon origin). Median overall survival duration in patients with metastatic spine tumor was 191 days. In addition to age, sex, and comorbidities, primary tumor sites (lung, liver and biliary tract, breast, stomach, and prostate) significantly affected survival rate. CONCLUSIONS This nationwide study was able to depict the burden of metastatic spine tumor in Korea. The metastatic spine tumor incidence rate is highest in the group of 70- to 79-year-old men. Average annual medical costs ranged from 12,734 USD to 15,556 USD. The mean annual hospital stay duration was from 70.8 days to 78.7 days. In addition to age, sex, and comorbidities, primary tumor sites significantly affected the survival rate in patients with metastatic spine tumor.

Increased Bone Mineral Density in Patients With Ossification of the Ligamentum Flavum: A Case-Control Study

The present study investigated the bone mineral density (BMD) and the prevalence of osteoporosis in an ossification of the ligamentum flavum (OLF) patient group and a matched control group. We also investigated the correlation of BMD with the number of spine levels exhibiting OLF. From January 1999 to August 2012, 120 patients with spinal OLF underwent dual-energy X-ray absorptiometry at our institute, and 102 of those were included in our study. Control group members were age, sex, and body mass index (BMI) matched to OLF group members on a 1:1 basis. Age, sex, and BMI were similar in the OLF and control groups. BMDs of the OLF and control groups were significantly different in the lumbar spine (mean T-scores: -0.2 ± 1.5 and -0.7 ± 1.5, respectively; p = 0.03). The prevalences of osteopenia and osteoporosis tended to be lower in the OLF group (28.3% and 4.0%, respectively) than those in the control group (31.3% and 9.1%, respectively); however, the differences were not statistically significant (p = 0.41). A significant positive correlation was detected between the lumbar spine BMD and the number of spine levels exhibiting OLF (p = 0.03).

Conventional Posterior Approach without Far Lateral Approach for Ventral Foramen Magnum Meningiomas

Objective We present our experience of conventional posterior approach without fat lateral approach for ventral foramen magnum (FM) meningioma (FM meningioma) and tried to evaluate the approach is applicable to ventral FM meningioma. Methods From January 1999 to March 2011, 11 patients with a ventral FM meningioma underwent a conventional posterior approach without further extension of lateral bony window. The tumor was removed through a working space between the dura and arachnoid membrane at the cervicomedullary junction with minimal retraction of medulla, spinal cord or cerebellum. Care should be taken not to violate arachnoid membrane. Results Preoperatively, six patients were of Nurick grade 1, three were of grade 2, and two were of grade 3. Median follow-up period was 55 months (range, 20-163 months). The extent of resection was Simpson grade I in one case and Simpson grade II in remaining 10 cases. Clinical symptoms improved in eight patients and stable in three patients. There were no recurrences during the follow-up period. Postoperative morbidities included one pseudomeningocele and one transient dysphagia with dysarthria. Conclusion Ventral FM meningiomas can be removed gross totally using a posterior approach without fat lateral approach. The arachnoid membrane can then be exploited as an anatomical barrier. However, this approach should be taken with a thorough understanding of its anatomical limitation.

Long-term Sequela of Intradural Extramedullary Tuberculoma in the Thoracic Dorsal Spinal Cord: Case Report and Review of the Literature

A 45-year old man, who had tuberculosis five years ago presented with paresthesia, decreased proprioception, and gait disturbance in the lower extremity which were aggravated for a month. Magnetic resonance imaging revealed the T3-7 intradural extramedullary fibrotic mass with dark signal intensity on T2-weighted images. The yellowish material in the thick fibrous mass was confirmed as caseous necrosis. Two days after the operation, the symptoms improved. Although quite rare, intradural extramedullary tuberculoma should be considered as a chronic sequel of the previous medical history of pulmonary tuberculosis or tuberculous meningitis.

Anti-inflammatory effect of Tauroursodeoxycholic acid in RAW 264.7 macrophages, Bone marrow-derived macrophages, BV2 microglial cells, and spinal cord injury

This study aimed to investigate the anti-inflammatory effects of tauroursodeoxycholic acid (TUDCA) after spinal cord injury (SCI) in rats. We induced an inflammatory process in RAW 264.7 macrophages, BV2 microglial cells, and bone marrow-derived macrophages (BMM) using lipopolysaccharide (LPS). The anti-inflammatory effects of TUDCA on LPS-stimulated RAW 264.7 macrophages, BV2 microglial cells, and BMMs were analyzed using nitric oxide (NO) assays, quantitative real-time polymerase chain reactions (qRT-PCR), and enzyme-linked immunosorbent assays (ELISA). The pathological changes in lesions of the spinal cord tissue were evaluated by hematoxylin & eosin (H&E) staining, luxol fast blue/cresyl violet-staining and immunofluorescent staining. TUDCA decreased the LPS-stimulated inflammatory mediator, NO. It also suppressed pro-inflammatory cytokines of tumor necrosis factor-α (TNF-α), interleukin 1-β (IL-1β), cyclooxygenase-2 (COX-2), and inducible nitric oxide synthase (iNOS) in both mRNA and protein levels. In addition, TUDCA decreased prostaglandin E2 (PGE2). After SCI, TUDCA supported the recovery of the injury site and suppressed the expression of inflammatory cytokines such as iNOS, CD68 and CD86. In addition, TUDCA induced the expression of anti-inflammatory cytokine, Arg-1. In conclusion, TUDCA inhibits inflammatory responses in RAW 264.7 macrophages, BV2 microglial cells, and BMMs. TUDCA can be a potential alternative drug for SCI.

Ursodeoxycholic Acid Inhibits Inflammatory Responses and Promotes Functional Recovery After Spinal Cord Injury in Rats

The aim of this study was to investigate the anti-inflammatory effects by ursodeoxycholic acid (UDCA) in rats with a spinal cord injury (SCI). A moderate mechanical compression injury was imposed on adult Sprague-Dawley (SD) rats. The post-injury locomotor functions were assessed using the Basso, Beattie, and Bresnahan (BBB) locomotor scale and the tissue volume of the injured region was analyzed using hematoxylin and eosin staining. The pro-inflammatory factors were evaluated by immunofluorescence (IF) staining, a quantitative real-time polymerase chain reaction (qRT-PCR), and enzyme-linked immunosorbent assay (ELISA). The phosphorylation of the extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and p38 in mitogen-activated protein kinase (MAPK) signaling pathways related to inflammatory responses were measured by Western blot assays. UDCA improved the BBB scores and promoted the recovery of the spinal cord lesions. UDCA inhibited the expression of glial fibrillary acidic protein (GFAP), tumor necrosis factor-α (TNF-α), ionized calcium-binding adapter molecule 1 (iba1), and inducible nitric oxide synthase (iNOS). UDCA decreased the pro-inflammatory cytokines of TNF-α, interleukin 1-β (IL-1β), and interleukin 6 (IL-6) in the mRNA and protein levels. UDCA increased the anti-inflammatory cytokine interleukin 10 (IL-10) in the mRNA and protein levels. UDCA suppressed the phosphorylation of ERK, JNK, and the p38 signals. UDCA reduces pro-inflammatory responses and promotes functional recovery in SCI in rats. These results suggest that UDCA is a potential therapeutic drug for SCI.

Association of ischemic stroke with ankylosing spondylitis: a nationwide longitudinal cohort study

BackgroundThe purpose of this nationwide age- and sex-matched longitudinal follow-up study was to investigate the risk of developing ischemic stroke in ankylosing spondylitis (AS).MethodsThe data in this study, spanning from January 1, 2010 to December 31, 2014, was obtained from a database maintained by the Korean National Health Insurance Service. A total of 12,988 patients with a diagnosis of AS were enrolled. The control group consisted of 64,940 age-sex-stratified matching subjects without AS. The 6year ischemic stroke incidence rate for each group was calculated using the Kaplan-Meier method. Cox proportional hazards regression analysis was used to estimate the hazard ratio of ischemic stroke.ResultsDuring the follow-up period, 73 patients (0.56%) in the AS group and 250 patients (0.38%) in the control group developed ischemic stroke (p = 0.0041). The hazard ratio of ischemic stroke in the AS group was 1.46 (95% confidence interval [95% CI], 1.13–1.90) after adjusting for age and sex. The adjusted hazard ratio of ischemic stroke in the AS group was 1.35 (95% CI, 1.04–1.75) after controlling for demographics and comorbid medical disorders. According to subgroup analysis, in female and diabetes and non-hypertension and dyslipidemia subgroups, ischemic stroke incidence rates were significantly higher in AS patients than those in control group.ConclusionOur nationwide longitudinal study suggests an increased risk of ischemic stroke in AS patients.