Hydration-induced rapid growth and regression after indirect revascularization of an anterior choroidal artery aneurysm associated with Moyamoya disease: A case report.

The prevalence of aneurysm formation in adults with Moyamoya disease (MMD) is higher than that in the general population. The treatment strategy is often individualized based on the patient's disease characteristics. A 22-year-old man was diagnosed with MMD after presenting a small thalamic intracerebral and subarachnoid hemorrhage in the quadrigeminal cistern. Cerebral angiography revealed a small aneurysm (2.42 mm) in the left anterior choroidal artery. Since the hemodynamics in the left hemisphere was compromised, an indirect bypass surgery was performed. The patient's condition deteriorated postoperatively because of poor perfusion of the internal carotid artery, and massive hydration was required. During neurocritical care, the aneurysm increased in size (5.33 mm). An observation strategy was adopted because of the distal aneurysmal location and the high risk involved. Subsequently, the patient recovered, and newly developed collateral flow appeared from the external carotid artery. Additionally, a dramatic size reduction of the aneurysm (1.51 mm) was noticed. Our case suggests that MMD-related dissecting aneurysms on a distal cerebral artery, which present a high risk of embolization, could be managed by indirectly reducing the hemodynamic burden. Massive hydration in such cases should be avoided or balanced to avoid the risk of rapid growth and aneurysm rupture.

Value of Additional Instrumented Fusion in the Treatment of Thoracic Ossification of the Ligamentum Flavum.

OBJECTIVE: The ossification of the ligamentum flavum (OLF) is one of the major causes of thoracic myelopathy. Surgical decompression with or without instrumented fusion is the mainstay of treatment. However, few studies have reported on the added effect of instrumented fusion. The objective of this study was to compare clinical and radiological outcomes between surgical decompression without instrumented fusion (D-group) and that with instrumented fusion (F-group). METHODS: A retrospective review was performed on 28 patients (D-group, n=17; F-group, n=11) with thoracic myelopathy due to OLF. The clinical parameters compared included scores of the Japanese Orthopedic Association (JOA), the Visual analogue scale of the back and leg (VAS-B and VAS-L), and the Korean version of the Oswestry disability index (K-ODI). Radiological parameters included the sagittal vertical axis (SVA), the pelvic tilt (PT), the sacral slope (SS), the thoracic kyphosis angle (TKA), the segmental kyphosis angle (SKA) at the operated level, and the lumbar lordosis angle (LLA; a negative value implying lordosis). These parameters were measured preoperatively, 1 year postoperatively, and 2 years postoperatively, and were compared with a linear mixed model. RESULTS: After surgery, all clinical parameters were significantly improved in both groups, while VAS-L was more improved in the Fgroup than in the D-group (-3.4±2.5 vs. -1.3±2.2, p=0.008). Radiological outcomes were significantly different in terms of changes in TKA, SKA, and LLA. Changes in TKA, SKA, and LLA were 2.3°±4.7°, -0.1°±1.4°, and -1.3°±5.6° in the F-group, which were significantly lower than 6.8°±6.1°, 3.0°±2.8°, and 2.2°±5.3° in the D-group, respectively (p=0.013, p<0.0001, and p=0.037). Symptomatic recurrence of OLF occurred in one patient of the D-group at postoperative 24 months. CONCLUSION: Clinical improvement was achieved after decompression surgery for OLF regardless of whether instrumented fusion was added. However, adding instrumented fusion resulted in better outcomes in terms of lessening the progression of local and regional kyphosis and improving leg pain. Decompression with instrumented fusion may be a better surgical option for thoracic OLF.

Trends in Treatment for Hemorrhoids, Fistula, and Anal Fissure: Go Along the Current Trends.

Recent trends in benign anal disease treatment are minimizing surgery to preserve normal anorectal anatomical unit and its functions. However, some surgeons still prefer and are confident with the use of conventional solid surgical methods. In this report, we will investigate the recent trends in the treatment for hemorrhoids, fistula, and anal fissure. The practice guidelines of advanced countries, including UK, Italy, France, USA, Japan, and ESCP, are referred to in this review. Opinions suggested in international meetings were also added. In the management of hemorrhoids, surgical treatments and office procedures were recommended according to a patient's status and preference. For the management of complex anal fistula, novel sphincter-preserving surgical techniques are more widely accepted than a sphincter-dividing procedure of immediate repair following fistulectomy. The treatment of anal fissures is well covered in the guidelines of the ASCRS.

Leptomeningeal Spread at the Diagnosis of Glioblastoma Multiforme: A Case Report and Literature Review.

Approximately two-thirds of glioblastoma (GBM) patients progress to leptomeningeal spread (LMS) within two years. While 90% of LMS cases are diagnosed during the progression and/or recurrence of GBM (defined as secondary LMS), LMS presentation at the time of GBM diagnosis (defined as primary LMS) is very rare. 18F-fluorodeoxy glucose positron emission tomography computed tomography (18F-FDG PET/CT) study helps to diagnose the multifocal spread of the malignant primary brain tumor. Our patient was a 31-year-old man with a tumorous lesion located in the right temporal lobe, a wide area of the leptomeninges, and spinal cord (thoracic 5/6, and lumbar 1 level) involvement as a concurrent manifestation. After the removal of the right temporal tumor, the clinical status progressed rapidly, showing signs of increased intracranial pressure and hydrocephalus caused by LMS. He underwent a ventriculoperitoneal shunt a week after craniotomy. During management, progression of cord compression, paraplegia, bone marrow suppression related to radiochemotherapy, intercurrent infections, and persistent ascites due to peritoneal metastasis of the LMS through the shunt system was observed. The patient finally succumbed to the disease nine months after the diagnosis of simultaneous GBM and LMS. The overall survival of primary LMS with GBM in our case was nine months, which is shorter than that of secondary LMS with GBM. The survival period after the diagnosis of LMS did not seem to be significantly different between primary and secondary LMS. To determine the prognostic effect and difference between primary and secondary LMS, further cooperative studies with large-volume data analysis are warranted.

Posterior Approach in C2-3 Disc Herniation: C1 Laminectomy, C2-3 Laminoplasty and Posterior Fixation in C2-3 Disc Herniation.

C2-3 disc herniation is rare and a definitive treatment of choice has not been established. The purpose of this case report is to suggest posterior approach as one of the best options. A 49-year-old man visited our clinic with a 7-year history of neck pain and occipital headache and a 2-month history of right arm pain. C2-3 intervertebral disc herniation of the central type was diagnosed on magnetic resonance imaging (MRI), and surgery was performed, including C1 laminectomy, C2-3 laminoplasty, and C2-3 posterior fixation. The posterior approach was used because the patient's neck was difficult to operate anteriorly. After 3 months postoperatively, MRI showed widened cerebrospinal fluid space at the C2-3 level. The visual analogue scale score for pain improved in the occipital area and right arm. However, the untouched protruded central disc, subjective weakness in right hand grasping, and numbness persisted. In conclusion, this case highlights posterior decompression and fixation as a good treatment of choice for decompression at the C2-3 level disc herniation, from where it is difficult to remove compressive lesions directly via the anterior corridor.

Proteome Analysis of Human Natural Killer Cell Derived Extracellular Vesicles for Identification of Anticancer Effectors.

Cancer immunotherapy is a clinically validated therapeutic modality for cancer and has been rapidly advancing in recent years. Adoptive transfer of immune cells such as T cells and natural killer (NK) cells has emerged as a viable method of controlling the immune system against cancer. Recent evidence indicates that even immune-cell-released vesicles such as NK-cell-derived exosomes also exert anticancer effect. Nevertheless, the underlying mechanisms remain elusive. In the present study, the anticancer potential of isolated extracellular vesicles (EVs) from expanded and activated NK-cell-enriched lymphocytes (NKLs) prepared by house-developed protocol was evaluated both in vitro and in vivo. Moreover, isolated EVs were characterized by using two-dimensional electrophoresis (2-DE)-based proteome and network analysis, and functional study using identified factors was performed. Our data indicated that the EVs from expanded and active NKLs had anticancer properties, and a number of molecules, such as Fas ligand, TRAIL, NKG2D, ß-actin, and fibrinogen, were identified as effector candidates based on the proteome analysis and functional study. The results of the present study suggest the possibility of NK-cell-derived EVs as a viable immunotherapeutic strategy for cancer.

Incidentally Found Intramuscular Hemangioma, Mimicking Traumatic Hematoma after Military Training: A Case Report.

This case report showed a young soldier complained of low back pain during military training. Intramuscular hematoma accompanied by the lumbar compression fracture was observed in computed tomography. However, the possibility of intramuscular tumors could not be ruled out through additional examinations, and thus surgically removed, and was diagnosed as cavernous hemangioma. This report is a rare and instructive case in which a hemangioma mimicked bleeding with the lumbar fracture.

The Long-term Reoperation Rate Following Surgery for Lumbar Stenosis: A Nationwide Sample Cohort Study With a 10-year Follow-up.

STUDY DESIGN: Retrospective cohort study of a nationwide sample database. OBJECTIVE: The objective of the present study was to compare the long-term incidence of reoperation for lumbar spinal stenosis (LSS) after anterior fusion, posterior fusion, and decompression. SUMMARY OF BACKGROUND DATA: Surgical treatment for LSS can be largely divided into 2 categories: decompression only and decompression with fusion. A previous nationwide study reported that fusion surgery was performed in 10% of patients with LSS, and the 10-year reoperation rate was approximately 17%. However, with the development of surgical techniques and changes in surgical trends, these results should be reassessed. METHODS: The National Health Insurance Service-National Sample Cohort of the Republic of Korea was utilized to establish a cohort of adult patients (N = 1400) who first underwent surgery for LSS during 2005 to 2007. Patients were followed for 8 to 10 years. Considering death before reoperation as a competing event, reoperation hazards were compared among surgical techniques using a Fine and Gray regression model after adjustment for sex, age, diabetes, osteoporosis, Charlson comorbidity index, severity of disability, type of medical coverage, and type of hospital. RESULTS: The overall cumulative incidence of reoperation was 6.2% at 2 years, 10.8% at 5 years, and 18.4% at 10 years. The cumulative incidence of reoperation was 20.6%, 12.6%, and 18.6% after anterior fusion, posterior fusion, and decompression, respectively, at 10 years postoperatively (P = 0.44). The first surgical technique did not affect the reoperation type (P = 0.27). Decompression was selected as the surgical technique for reoperation in 83.5% of patients after decompression, in 72.7% of patients after anterior fusion, and in 64.3% of patients after posterior fusion. CONCLUSION: The initial surgical technique did not affect reoperation during the 10-year follow-up period. Decompression was the most commonly used technique for reoperation. LEVEL OF EVIDENCE: 4.

Risk Factors for Symptomatic Contralateral Foraminal Stenosis After Unilateral Transforaminal Lumbar Interbody Fusion.

OBJECTIVE: The most common cause of contralateral symptoms after unilateral transforaminal lumbar interbody fusion (TLIF) is contralateral foraminal stenosis (FS). This retrospective cohort study aimed to investigate the cause of and risk factors for contralateral FS after unilateral TLIF with a single cage. METHODS: Patients with degenerative lumbar spinal disorders who underwent unilateral TLIF at L4-5 were divided into 2 groups: those without contralateral radicular symptoms after surgery (group A; n = 340) and those with contralateral radicular symptoms after surgery (group B; n = 16). We investigated the influence of various radiological and cage-related factors on postoperative contralateral FS with radicular symptoms. The cage location indicates whether the cage's anterior tip crosses the disc midline-exceeding 50%-and in such a case, how far. RESULTS: Group B showed significantly increased postoperative coronal angle and sagittal angle and decreased contralateral foraminal height and foraminal area. Statistically significant (P < 0.01) factors according to the multivariate logistic regression analysis were the preoperative sagittal range of motion (odds ratio [OR]: 1.562, P = 0.004) and cage location (OR: 2.047, P = 0.015). The cutoff values for the sagittal range of motion and the cage location were 9.0° and 50.5%, respectively. The preoperative and postoperative 6-month visual analog scale scores and Oswestry disability index values were not significantly different between the groups. CONCLUSIONS: The 2 most meaningful risk factors were the preoperative sagittal range of motion and cage location. Inserting the cage beyond the disc midline, especially in patients with a high preoperative sagittal range of motion (≥9.0°), would help reduce postoperative complications.

The Efficacy of Ultrasonic Bone Scalpel for Unilateral Cervical Open-Door Laminoplasty: A Randomized Controlled Trial.

BACKGROUND: In cervical open-door laminoplasty for cervical myelopathy, a high-speed rotatory drill and rongeurs are used to make unicortical troughs and bicortical openings in the laminae. The lamina is reflected at the trough to enlarge the spinal canal, followed by bone healing on the hinge side to stabilize laminoplasty. The ultrasonic bone scalpel (UBS) has been used due to theoretical advantages including a better hinge union rate, less soft tissue trauma, less neurological injury, and shorter operative time. OBJECTIVE: To assess the superiority of UBS for hinge union compared to the drill through randomized controlled trial. METHODS: In 190 randomly allocated cervical myelopathy patients, the trough and opening at the lamina were made using either the drill (n = 95) or UBS (n = 95) during 2015 to 2018. The primary outcome was the hinge union rate on 6-mo postoperative computed tomography. Secondary outcomes included the hinge union rate at 12 mo, the operative time, intraoperative/postoperative bleeding, neurological injury, complications, and clinical outcomes over a 24-mo follow-up. RESULTS: Hinge union in all laminae was achieved in 60.0% (drill) and 43.9% (UBS) of patients at 6 mo (intention-to-treat analysis; P = .02; odds ratio, 2.1) and in 91.9% (drill) and 86.5% (UBS) at 12 mo. Dural injury only occurred in the drill group (2.1%), and the UBS group showed significantly less intraoperative bleeding (P < .01). The other secondary outcomes did not differ between groups. CONCLUSION: The hinge union rate was inferior in the UBS group at 6 mo postoperatively, but UBS was efficacious in reducing dural injuries and bleeding.

Progression of Ossification of the Posterior Longitudinal Ligament after Cervical Total Disc Replacement.

OBJECTIVE: Total disc replacement (TDR) is frequently performed anterior approaching method for the patients diagnosed with cervical disc herniation. This study aimed to assess the degree of ossification of the posterior longitudinal ligament (OPLL) progression after cervical TDR. METHODS: Twenty-two male soldiers who underwent cervical TDR surgery from 2009 to 2016 and were followed-up for more than 12 months were enrolled. The enrolled patients were classified as; 1) patients with pre-existing OPLL and without; and 2) patient showing progression of OPLL or not. RESULTS: Twenty-two men were included in the analysis. The mean follow-up period from the surgery was 41.4 months (range, 12-114 months). The mean age of all patients was 40.7 years (range, 31-52 years). TDR-only was used in 7 cases, and the hybrid surgery (TDR+ACDF) was used in 15 cases. The incidence of progression or newly development of OPLL was significantly higher in pre-existing OPLL group (p=0.01). In 11 cases showing the progression of the OPLL, the mean size of OPLL progression was 4.16 mm (range, 0.34-18.87 mm) in the longitudinal height and 1.57 mm (range, 0.54-3.91 mm) in thickness. CONCLUSION: The progression of OPLL after cervical TDR was more frequent in patients with pre-existing OPLL than in patients without OPLL. Even though TDR is a major alternative to the treatment of cervical lesions to preserve vertebral segmental motion, careful attention should be paid to whether TDR should be used in patients with OPLL and this should be fully explained to the patient.

Positional effect of preoperative neuronavigational magnetic resonance image on accuracy of posterior fossa lesion localization.

OBJECTIVE: The aim of this study was to analyze the positional effect of MRI on the accuracy of neuronavigational localization for posterior fossa (PF) lesions when the operation is performed with the patient in the prone position. METHODS: Ten patients with PF tumors requiring surgery in the prone position were prospectively enrolled in the study. All patients underwent preoperative navigational MRI in both the supine and prone positions in a single session. Using simultaneous intraoperative registration of the supine and prone navigational MR images, the authors investigated the images' accuracy, spatial deformity, and source of errors for PF lesions. Accuracy was determined in terms of differences in the ability of the supine and prone MR images to localize 64 test points in the PF by using a neuronavigation system. Spatial deformities were analyzed and visualized by in-house-developed software with a 3D reconstruction function and spatial calculation of the MRI data. To identify the source of differences, the authors investigated the accuracy of fiducial point localization in the supine and prone MR images after taking the surface anatomy and age factors into consideration. RESULTS: Neuronavigational localization performed using prone MRI was more accurate for PF lesions than routine supine MRI prior to prone position surgery. Prone MRI more accurately localized 93.8% of the tested PF areas than supine MRI. The spatial deformities in the neuronavigation system calculated using the supine MRI tended to move in the posterior-superior direction from the actual anatomical landmarks. The average distance of the spatial differences between the prone and supine MR images was 6.3 mm. The spatial difference had a tendency to increase close to the midline. An older age (> 60 years) and fiducial markers adjacent to the cervical muscles were considered to contribute significantly to the source of differences in the positional effect of neuronavigation (p < 0.001 and p = 0.01, respectively). CONCLUSIONS: This study demonstrated the superior accuracy of neuronavigational localization with prone-position MRI during prone-position surgery for PF lesions. The authors recommend that the scan position of the neuronavigational MRI be matched with the surgical position for more precise localization.

The Long-term Reoperation Rate Following Surgery for Lumbar Herniated Intervertebral Disc Disease: A Nationwide Sample Cohort Study With a 10-year Follow-up.

STUDY DESIGN: A retrospective cohort study of a nationwide sample database. OBJECTIVE: The objective of the present study was to compare the long-term incidence of reoperation for lumbar herniated intervertebral disc disease (HIVD) after major surgical techniques (open discectomy, OD; laminectomy; percutaneous endoscopic lumbar discectomy, PELD; fusion). SUMMARY OF BACKGROUND DATA: HIVD is a major spinal affliction; if the disease is intractable, surgery is recommended. Considering both the aging of patients and the chronicity of lumbar degenerative disease, the effect of surgical treatment for the lumbar spine should be durable for as long as possible. METHODS: The National Health Insurance Service-National Sample Cohort (NHIS-NSC) of Republic of Korea was utilized to establish a cohort of adult patients (N = 1856) who underwent first surgery for lumbar HIVD during 2005 to 2007. Patients were followed for 8 to 10 years. Considering death before reoperation as a competing event, reoperation hazards were compared among surgical techniques using the Fine and Gray regression model after adjustment for age, gender, Charlson comorbidity score, osteoporosis, diabetes, the severity of disability, insurance type, and hospital type. RESULTS: The overall cumulative incidences of reoperation were 4% at 1 year, 6% at 2 years, 8% at 3 years, 11% at 5 years, and 16% at 10 years. The cumulative incidences of reoperation were 16%, 14%, 16%, and 10% after OD, laminectomy, PELD, and fusion, respectively, at 10 years postoperation, with no difference among the surgical techniques. However, the distribution of reoperation types was significantly different according to the first surgical technique (P < 0.01). OD was selected as the reoperation surgical technique in 80% of patients after OD and in 81% of patients after PELD. CONCLUSION: The probability of reoperation did not differ among OD, laminectomy, PELD, and fusion during the 10-year follow-up period. However, OD was the most commonly used technique in reoperation. LEVEL OF EVIDENCE: 4.

Increased Proportion of Fusion Surgery for Degenerative Lumbar Spondylolisthesis and Changes in Reoperation Rate: A Nationwide Cohort Study With a Minimum 5-Year Follow-up.

STUDY DESIGN: A retrospective cohort study. OBJECTIVE: The objectives of the present study were to examine the changes in the number of surgeries, surgical methods selected, and reoperation rates between the years 2003 and 2008. SUMMARY OF BACKGROUND DATA: The selection of the appropriate surgical method between decompression-only (D) and decompression plus fusion (DF) represents a challenging clinical dilemma in patients with degenerative lumbar spinal spondylolisthesis. DF is selected in greater than 90% of patients, mostly due to the associated low reoperation rate. However, the outcomes of D have been improved with minimally invasive decompression surgery techniques. METHODS: The Health Insurance Review and Assessment Service database was used to create cohorts of all Korean patients who underwent surgery for degenerative lumbar spinal spondylolisthesis in 2003 (2003 cohort, n = 5624) and 2008 (2008 cohort, n = 11,706). All patients were followed up for at least 5 years. Reoperation was defined as the occurrence of any type of second lumbar surgery during the follow-up period. The probabilities of reoperation were calculated using the Kaplan-Meier method. RESULTS: The number of surgeries increased 2.08-fold in 2008. Patients older than 60 years comprised 38.6% of the 2003 cohort and 52.4% of the 2008 cohort. The proportion of DF surgery was 31.13% in the 2003 cohort but 91.54% in the 2008 cohort. However, the high proportion of fusion surgery failed to reduce the reoperation probability in the 2008 cohort (8.1%) compared with that in the 2003 cohort (6.2%). The cost of DF was US$5264 and that of D was $2719 in 2008. DF decreased the reoperation probability by 1% at the cost of $421/patient in the 2008 cohort. CONCLUSION: The increased proportion of fusion surgery without improvement in reoperation probability in an aging society may be cautiously addressed in deciding future health policies. LEVEL OF EVIDENCE: 4.

Postoperative Longitudinal Outcomes in Patients with Residual Disc Fragments after Percutaneous Endoscopic Lumbar Discectomy.

BACKGROUND: Residual disc fragments are observed on immediate postoperative magnetic resonance imaging (MRI) in 2.8-15% of patients after percutaneous endoscopic lumbar discectomy (PELD). Considering the known postoperative longitudinal outcomes in patients with residual disc tissue, a 'watchful waiting' strategy may be preferable to immediate re-operation in patients with asymptomatic residual disc material. OBJECTIVES: The aim of the present study was to compare the longitudinal clinical outcomes between PELD patients in whom the complete removal of disc fragments was achieved (complete group) and those in whom residual disc fragments were observed on postoperative MRI (residual group). STUDY DESIGN: Retrospective nested case-control study. METHODS: A total of 225 patients were included (complete group, n=187 and residual group, n=38). Clinical assessments were performed using the visual analog pain score for the leg (VAS-L, x/10) and back (VAS-B, x/10) and the Korean version of the Oswestry Disability Index (K-ODI, x/45). A linear mixed-effects model was used to analyze changes during the first 24 postoperative months. RESULTS: One month after surgery, significant improvements in the VAS-L, VAS-B and K-ODI values were observed and were maintained during the first 24 postoperative months. No differences in these changes were noted between the groups. Early re-operation (during the first 3 postoperative months) was performed in 3 patients in the residual group (7.9%) and in 4 patients in the complete group (2.1%) (P = 0.10). LIMITATIONS: First, the study design was retrospective. Moreover, the number of patients was relatively small and therefore insufficient to achieve robust statistical power. Second, we did not explore the radiological outcomes in patients with asymptomatic residual disc material because follow-up MRI was only obtained to document symptom recurrence. CONCLUSION: When residual disc tissue is observed in asymptomatic patients, a 'watchful waiting' strategy may be preferable to immediate re-operation. However, an increased early re-operation rate is expected for patients with residual disc tissue. KEY WORDS: Discectomy, endoscopes, longitudinal studies, patient-reported outcome, percutaneous, reoperation, spine, residual disc.

Increased Volume of Surgery for Lumbar Spinal Stenosis and Changes in Surgical Methods and Outcomes: A Nationwide Cohort Study with a 5-Year Follow-Up.

OBJECTIVE: Examining spine surgery patterns over time is crucial to provide insights into variations and changes in clinical decision making. Changes in the number of surgeries, surgical methods, reoperation rates, and cost-effectiveness were analyzed for all patients who underwent surgery for lumbar spinal stenosis without spondylolisthesis in 2003 (2003 cohort) and 2008 (2008 cohort). METHODS: The national health insurance database was used to create the 2003 cohort (n = 10,990) and 2008 cohort (n = 27,942). The surgical methods were classified into decompression and fusion surgery. The cumulative reoperation probability between those surgeries was calculated using the Kaplan-Meier method in the 2003 cohort and 2008 cohort. Comparison of the incremental cost-effectiveness ratios showed the additional direct cost of a 1% change in the reoperation probability. RESULTS: The surgical volume increased 2.54-fold in the 2008 cohort. The age-adjusted number of surgeries per 1 million people increased 2.6-fold (from 154 in the 2003 cohort to 399 in the 2008 cohort) in aged patients and 1.9-fold (from 154 in the 2003 cohort to 291 in the 2008 cohort) in patients 20-59 years old in the 2008 cohort. The proportion of fusion surgeries increased from 20.3% in the 2003 cohort to 37.0% in the 2008 cohort. In total, the 5-year reoperation probabilities increased from 8.1% in the 2003 cohort to 11.2% in the 2008 cohort. Fusion decreased the reoperation probability by 1% at the cost of 1,711 U.S. dollars. CONCLUSIONS: The increased numbers of spinal surgeries, fusion surgeries, and surgeries in older patients in a recent cohort were noteworthy. However, the increased surgical volume and fusion surgeries did not reduce the reoperation rate.

Postoperative Changes in Moderate to Severe Nonspecific Low Back Pain After Cervical Myelopathy Surgery.

OBJECTIVE: Cervical myelopathy patients sometimes experience concurrent nonspecific moderate to severe low back pain (msLBP). However, postoperative changes in msLBP after cervical myelopathy surgery have rarely been reported. Awareness of postoperative changes in msLBP may be helpful in consultation. Therefore, the objective of this study was to examine postoperative changes in msLBP. METHODS: Patients with cervical myelopathy and msLBP (a visual analog pain score ≥5/10) were reviewed prospectively, and 53 patients (male:female ratio, 28:25; mean age, 63.1 years) were enrolled. Cervical myelopathy was assessed with the Japanese Orthopedic Association score. Cervical laminoplasty was performed in 49 patients, and anterior cervical discectomy and fusion were performed in 4 patients. The patients were followed up postoperatively at 1, 3, 6, and 12 months and yearly thereafter. The primary endpoint was improvement of the visual analog scale score for back pain (VAS-B) by greater than 2.6/10. Prognostic factors were analyzed postoperatively at 12 months. The mean follow-up period was 16 ± 9 months. RESULTS: MsLBP improved in 58%, 49%, 53%, 52%, and 59% of the patients at 1, 3, 6, 12, and 24 months postoperatively, respectively. The VAS-B worsened after improvement or vice versa in approximately 30% of the patients during the follow-up period. Lumbar decompression operations were performed in 5 patients at 4, 6, 7, 15, and 16 months postoperatively. The recovery rate of the JOA score was a positive prognostic factor. CONCLUSIONS: Although the exact pathophysiology was not demonstrated, cervical myelopathy surgery may directly and indirectly improve msLBP.

The Recovery of Motor Strength after Posterior Percutaneous Endoscopic Cervical Foraminotomy and Discectomy.

OBJECTIVE: Cervical radiculopathy infrequently presents with motor weakness. Motor weakness was improved in >90% of patients after anterior cervical discectomy and fusion or posterior cervical foraminotomy. Posterior percutaneous endoscopic cervical foraminotomy and discectomy (PECF) is an alternative surgical technique, but the outcome of motor weakness has not been reported. Our objective was to demonstrate the longitudinal outcomes of motor weakness after PECF. METHODS: A retrospective review of 106 consecutive patients was performed. Preoperative motor weakness was graded as mild (IV/V strength) or severe (less than III/V strength). The patients visited the outpatient clinic at 1, 3, 6, and 12 months after surgery and yearly thereafter. Improvement was defined as an improved weakness of more than 1 grade, and normalization was defined as the recovery of complete motor strength. RESULTS: Motor weakness preoperatively presented in 76 of 106 (72%) patients (49%, mild weakness; 23%, severe weakness). After PECF, the weakness improved in 72 of 76 (95%) patients and normalized in 65 of 76 (86%) patients. In the patients with mild weakness, the normalization rates were 48%, 81%, 90%, and 96% at postoperative months 1, 3, 6, and 12, respectively. In the patients with severe weakness, the improvement rates were 50%, 71%, 83%, 88%, and 92%, and the normalization rates were 8%, 38%, 58%, 58%, and 63% at postoperative months 1, 3, 6, 12, and 24, respectively. CONCLUSIONS: Preoperative motor weakness was improved in 95% of the patients after PECF, but motor weakness was not normalized in 37% of the patients with severe weakness.

The Ratio-Based N Staging System Can More Accurately Reflect the Prognosis of T4 Gastric Cancer Patients with D2 Lymphadenectomy Compared with the 7th American Joint Committee on Cancer/Union for International Cancer Control Staging System.

PURPOSE: The utility of N classification has been questioned after the 7th edition of the American Joint Committee on Cancer (AJCC)/Union for International Cancer Control (UICC) was published. We evaluated the correlation between ratio-based N (rN) classification with the overall survival of pathological T4 gastric cancer patients who underwent D2 lymphadenectomy. MATERIALS AND METHODS: We reviewed 222 cases of advanced gastric cancer patients who underwent curative gastrectomy between January 2006 and December 2015. The T4 gastric cancer patents were classified into four groups according to the lymph node ratio (the number of metastatic lymph nodes divided by the retrieved lymph nodes): rN0, 0%; rN1, ≤13.3%; rN2, ≤40.0%; and rN3, >40.0%. RESULTS: The rN stage showed a large down stage migration compared with pathological T4N3 (AJCC/UICC). There was a significant difference in overall survival between rN2 and rN3 groups in patients with pT4N3 (P=0.013). In contrast, the difference in metastatic lymph nodes was not significant in these patients (≥16 vs. <15; P=0.177). In addition, the rN staging system showed a more distinct difference in overall survival than the pN staging system for pathological T4 gastric cancer patients. CONCLUSIONS: Our results confirm that rN staging could be a good alternative for pathological T4 gastric cancer patients who undergo D2 lymphadenectomy. However, before applying this system to gastric cancer patients who undergo D2 lymphadenectomy, a larger sample size is required to further evaluate the usefulness of the rN staging system for all stages, including less advanced stages.