Application and Advantages of the Trans-Unco-Discal (TUD) Approach for Cervical Spondylotic Myelopathy and Radiculopathy: Classification and Modification of Surgical Technique Based on the Location of Spinal Cord and/or Nerve Root Compression

Purpose: We assess the application and advantages of modifying the trans-unco-discal (TUD) approach which we underwent for cervical myelo-radiculopathy. We present the surgical techniques of the modified TUD approach. Materials and Methods: The material was 180 cases where anterior cervical decompression (ACD) was performed by the modified TUD approach. We classified the material into four groups based on the location of the nerve root and/or spinal cord compression: I, compression of the root at intervertebral foramen (IVF); II, compression of the posterior margin of the vertebral body; III, compression of the IVF and posterior margin of the vertebral body; IV, compression of the bilateral IVF and posterior margin of the vertebral body. We applied the modified TUD approach to these four types. We present the surgical procedures and techniques for the modified TUD approach. The Japanese orthopedic association (JOA) score and neuroradiological alignment were examined. Results: The improvement rate of the JOA score was 78.4% at 6 months post-surgery and 77.5% in the most recent examinations. By the modified TUD approach, compressive lesions of the spinal cord and/or nerve roots were removed, and good alignment was acquired and sustained. Conclusions: ACD by the modified TUD approach safely achieved appropriate decompression for the spinal cord and/or nerve roots, and the patients had a high improvement rate and good alignment. Complications were less common than with other surgical procedures. If the TUD approach and endoscopic approaches can be combined, their application to new area is anticipated.

Parent Artery Occlusion for a Dissecting Posterior Cerebral Artery Aneurysm in the P4 Segment Presenting with Ischemic Stroke and Rapid Growth: A Case Report

A dissecting aneurysm in the P4 segment of the posterior cerebral artery (PCA) is extremely rare, and its treatment is sometimes challenging. Endovascular parent artery occlusion (PAO) was performed for an unruptured P4 segment dissecting PCA aneurysm presenting with ischemic stroke and rapid growth. A 70-year-old man was rushed to our emergency department due to a right-sided headache and a visual field defect. Head magnetic resonance imaging showed a right occipital lobe ischemic stroke, with right PCA occlusion and aneurysm formation in the P4 segment. The diagnosis was PCA dissection in the calcarine artery, and oral aspirin was started. Within a week, the dissecting aneurysm had enlarged progressively to 6.2 mm in diameter. Thus, PAO with coils was performed as a preventive measure against aneurysm rupture, assuming that complication risks were low because the tributary area of the dissecting PCA had already infarcted. A 6-Fr guiding sheath was introduced from the right brachial artery to the right vertebral artery, and a microcatheter/microguidewire was placed into the true lumen of the calcarine artery distal to the aneurysm. PAO with coils was performed, and the blood flow to the aneurysm was completely obliterated. After the treatment, the known infarction in the right occipital lobe was enlarged, but no new neurological symptoms developed. The patient was discharged independently on postoperative day 3. Treatment for a distal PCA dissecting aneurysm is challenging. PAO with coils is one of the reasonable choices, especially when a visual field defect has already developed.

The Symptomatic Calcification and Ossification of the Ligamentum Flavum in the Spine: Our Experience and Review of the Literature

INTRODUCTION

We report our experience regarding the clinical features and pathological findings of the calcification of the ligamentum flavum (CLF) and ossification of the ligamentum flavum (OLF) in the spine. In addition, we reviewed the previous studies on CLF and OLF to enhance the understanding of these conditions.

MATERIALS AND METHODS

We compared the clinical, radiological, and histopathological features of CLF and OLF.

RESULTS

In CLF, a computed tomography (CT) scan showed egg-shaped or speck-like calcification in the ligamentum flavum. Magnetic resonance (MR) imaging demonstrated spinal cord compression due to a thickened ligamentum flavum, which appeared as a low-intensity mass. Pathological findings demonstrated fused islands of calcification resembling sand-like calcification. In OLF, CT showed beak-like ossification extending into the intervertebral foramen. MR imaging demonstrated spinal cord compression by a low-intensity mass. Pathological findings revealed laminar ossification of LF with chondrocytes near the calcification and laminar hyaline cartilage.

CONCLUSIONS

CLF and OLF appear to be distinct entities based on their clinical, neuroradiological, histopathological, and pathogenetic features. We suggest that the causes of CLF include both metabolic and dystrophic factors, while the pathogenesis of OLF is characterized by enchondral ossification induced by a genetic cascade triggered by shearing/tension stress.

Surgical Management of Chiari Malformation Type I and Instability of the Craniocervical Junction Based on Its Pathogenesis and Classification

We investigated the mechanism underlying Chiari malformation type I (CM-I) and classified it according to the morphometric analyses of posterior cranial fossa (PCF) and craniocervical junction (CCJ). Three independent subtypes of CM-I were confirmed (CM-I types A, B, and C) for 484 cases and 150 normal volunteers by multiple analyses. CM-I type A had normal volume of PCF (VPCF) and occipital bone size. Type B had normal VPCF and small volume of the area surrounding the foramen magnum (VAFM) and occipital bone size. Type C had small VPCF, VAFM, and occipital bone size. Morphometric analyses during craniocervical traction test demonstrated instability of CCJ. Foramen magnum decompression (FMD) was performed in 302 cases. Expansive suboccipital cranioplasty (ESCP) was performed in 102 cases. Craniocervical posterolateral fixation (CCF) was performed for CCJ instability in 70 cases. Both ESCP and FMD showed a high improvement rate of neurological symptoms and signs (84.4%) and a high recovery rate of the Japanese Orthopaedic Association (JOA) score (58.5%). CCF also showed a high recovery rate of the JOA score (69.7%), with successful joint stabilization (84.3%). CM-I type A was associated with other mechanisms that caused ptosis of the brainstem and cerebellum (CCJ instability and traction and pressure dissociation between the intracranial cavity and spinal canal cavity), whereas CM-I types B and C demonstrated underdevelopment of the occipital bone. For CM-I types B and C, PCF decompression should be performed, whereas for small VPCF, ESCP should be performed. CCF for CCJ instability (including CM-I type A) was safe and effective.

Discrimination of cellulose fabrics using infrared spectroscopy and newly developed discriminant analysis

Identifying cellulose fibers in fabric products is necessary for quality control and appropriate distribution but can be difficult because of their similarities. A novel technique to identify cellulose fabrics has been developed that uses infrared spectroscopy with the attenuated total reflection (ATR) method, evaluated with an improved Fisher's discriminant analysis including regularization coefficients and orthogonal decompositions. Sequential discrimination of six different types of cellulose fibers -cotton, ramie, and linen, which are natural fibers, and rayon, cupra, and lyocell, which are regenerated fibers- was achieved using the new technique.

60Fe and 244Pu deposited on Earth constrain the r-process yields of recent nearby supernovae

Half of the chemical elements heavier than iron are produced by the rapid neutron capture process (r-process). The sites and yields of this process are disputed, with candidates including some types of supernovae (SNe) and mergers of neutron stars. We search for two isotopic signatures in a sample of Pacific Ocean crust-iron-60 (⁶⁰Fe) (half-life, 2.6 million years), which is predominantly produced in massive stars and ejected in supernova explosions, and plutonium-244 (²⁴⁴Pu) (half-life, 80.6 million years), which is produced solely in r-process events. We detect two distinct influxes of ⁶⁰Fe to Earth in the last 10 million years and accompanying lower quantities of ²⁴⁴Pu. The ²⁴⁴Pu/⁶⁰Fe influx ratios are similar for both events. The ²⁴⁴Pu influx is lower than expected if SNe dominate r-process nucleosynthesis, which implies some contribution from other sources.

Quantitative Analysis of Near-Infrared Indocyanine Green Videoangiography for Predicting Functional Outcomes After Spinal Intramedullary Ependymoma Resection

BACKGROUND

One of the most critical steps in surgery for spinal intramedullary ependymomas is the resection of small feeding arteries from the anterior spinal artery with anatomical preservation of the normal circulation of the ventral spinal cord.

OBJECTIVE

To quantitatively analyze the microcirculation of the ventral spinal cord by near-infrared indocyanine green videoangiography (ICG-VA) after the spinal intramedullary ependymoma resection.

METHODS

This retrospective study included 12 patients (7 male and 5 female; average age 55.2 years, range 36-79 years). Patients' neurological conditions were assessed based on the modified McCormick functional schema of grade 1 (neurologically normal) to 5 (severe deficit). Postoperative functional assessment was conducted at least 3 months after surgery. Quantitative analysis of vascular flow dynamics was carried out following spinal intramedullary ependymoma resection. Fluorescence intensities were measured and the indocyanine green (ICG) intensity-time curves were analyzed and compared with the functional outcomes after surgery.

RESULTS

Microscopically total or subtotal resection of the intramedullary ependymoma was achieved in all cases. Average peak time on ICG-VA was significantly shorter in the postoperative functional grade 1 to 2 group than in the postoperative functional grade 3 to 5 group, but there was no significant difference in average peak intensity between the 2 groups. Postoperative functional grade and the peak time of ICG, but not peak intensity, appeared correlated.

CONCLUSION

To the best of our knowledge, this is the first report showing that quantitative analysis of ICG-VA may predict functional outcomes after spinal intramedullary ependymoma resection.

Effect of 4-phenylbutyrate and valproate on dominant mutations of WFS1 gene in Wolfram syndrome

PURPOSE

Wolfram syndrome (WS) is a rare disorder caused by mutations in WFS1 that is characterized by diabetes mellitus, optic atrophy, sensorineural deafness, diabetes insipidus, and neurodegeneration. This disease is usually inherited as an autosomal recessive trait, but an autosomal dominant form has been reported. WFS1 encodes a transmembrane protein, which is a maintenance component of endoplasmic homeostasis. These dominant mutations were thought to increase endoplasmic reticulum (ER) stress. Recent studies suggest that 4-phenylbutyrate (PBA) and valproate (VPA) reduce ER stress. The objective of this study was to analyze the effect of PBA and VPA on dominant WFS1 mutants in vitro.

METHODS

We determined whether dominant WFS1 mutants (p.His313Tyr, p.Trp314Arg, p.Asp325_Ile328del, p.Glu809Lys, and p.Glu864Lys) have the dominant negative effect using a luciferase assay of ER stress response element marker as ER stress. Moreover, the rescue of cell apoptosis induced by dominant WFS1 mutants following treatment with PBA or VPA was determined by quantitative real-time PCR of C/EBP homologous protein (CHOP) mRNA expression.

RESULTS

These mutants showed the dominant negative effect on the wild-type WFS1. In addition, the levels of ER stress and CHOP mRNA were significantly elevated by all dominant WFS1 mutants. After treatment with PBA or VPA, ER stress and cell apoptosis were reduced in each mutant.

CONCLUSIONS

PBA and VPA could reduce the ER stress and cell apoptosis caused by dominant WFS1 mutants.

Low recurrence after Simpson grade II resection of spinal benign meningiomas in a single-institute 10-year retrospective study

The objective of this study was to more fully understand the optimal neurosurgical strategy for spinal benign meningiomas from a medium to long-term perspective. This retrospective study included a cohort of 35 patients with a diagnosis of spinal meningioma who were first operated at our institute over the past 10 years and followed-up for at least 2 years after surgery. The inclusion criterion for the study was the pathological diagnosis finally verified as benign meningioma of World Health Organization (WHO) grade 1. The average follow-up duration after surgery was 61.0 months. The location of the spinal meningioma was classified into ventral or dorsal type based on the operative video record and the preoperative MR images. The extent of resection of the spinal meningioma was carefully determined based on the Simpson grade. The average neurological condition was significantly improved at the final follow-up. Simpson grade I or II resection was achieved in 31 of 35 cases (88.6%). No Simpson grade I or II cases showed local recurrence during follow-up. Tumor recurrence was noted in 2 of 4 cases of Simpson grade IV resection. One case has been followed-up without any re-operation because of no neurological deterioration, and the other case underwent stereotactic radiosurgery. This study suggested that meticulous Simpson grade II resection of spinal benign meningiomas of WHO grade 1 may be good enough from a medium to long-term follow-up perspective, though longer follow-up is absolutely necessary.

Health-Related Quality of Life After Microscopic Total Removal of Spinal Intramedullary Ependymomas in a Single-Institute 3-Year Prospective Study

OBJECTIVE

Health-related quality of life (HRQOL) after surgery for spinal intramedullary benign encapsulated tumors remains unclear. A single-institute, 3-year, prospective study was conducted to examine HRQOL after microscopic total removal of spinal intramedullary ependymomas using a safe and precise strategy.

METHODS

A cohort of 20 patients with a possible diagnosis of spinal intramedullary benign ependymomas was recruited. Patients who underwent microscopic total removal of the tumor and for whom the pathologic diagnosis was verified as World Health Organization grade II benign ependymoma were included. Sixteen patients (average age, 48.7 years) were eligible for study analysis. Careful assessment was performed for all patients before and 6-12 months after surgery. The 36-Item Short Form Health Survey was used to assess HRQOL, with the surveyor recording answers as reported by the individual patient.

RESULTS

Average total HRQOL score was 431.1 before surgery and was maintained at 434.2 at 6-12 months postoperatively. Patients with mild functional symptoms tended to demonstrate a higher total HRQOL score preoperatively compared with patients with moderate to severe functional symptoms. A strong correlation was noted between postoperative functional conditions and preservation of HRQOL.

CONCLUSIONS

This is the first study focusing on HRQOL after microscopic total removal of spinal intramedullary ependymomas. This study suggested that radical surgery using a safe and precise strategy appears justifiable and that preservation of neurologic function after surgery may lead to maintenance of postoperative HRQOL.

Safety and Efficacy of Syringoperitoneal Shunting with a Programmable Shunt Valve for Syringomyelia Associated with Extensive Spinal Adhesive Arachnoiditis: Technical Note

OBJECTIVE

Although syringomyelia associated with extensive spinal adhesive arachnoiditis (SAA) can be a progressive disease that has potentially devastating clinical consequences, its surgical resolution has remained poorly defined. The aim of the present study was to verify the safety and efficacy of syringoperitoneal shunting for syringomyelia associated with extensive SAA.

METHODS

The present retrospective study included 15 patients who had undergone syringoperitoneal shunting with a programmable shunt valve for the diagnosis of syringomyelia associated with extensive SAA from October 2012 to June 2018. The shunt pressure was appropriately adjusted according to the postoperative sequential clinical condition and change in syringomyelia evaluated using magnetic resonance imaging. The average postoperative follow-up duration was 32.7 months.

RESULTS

No surgery-related complications such as shunt dysfunction or infection occurred during the follow-up period, except for 2 patients with minor issues with the shunt tube. The average shunt pressure at the last follow-up examination was 4.5 cm H₂O. The findings from the clinical assessment suggested that the average grade on the sensory pain scale was 2.9 before surgery and had improved significantly to 2.5 at the most recent follow-up examination. Radiological analysis suggested that improvement of syringomyelia was noted in 14 of the 15 patients (93.3%), with no cases of radiological aggravation. No recurrence of syringomyelia developed during the follow-up period in the present study.

CONCLUSION

Syringoperitoneal shunting with a programmable shunt valve was safe and effective for clinical control of syringomyelia associated with extensive SAA. Long-term follow-up is mandatory to monitor for shunt dysfunction and mechanical trouble.

High Cervical Lateral Approach to Safely Remove the Cystic Retro-odontoid Pseudotumor: Technical Note

Surgery for neoplastic or vascular lesions at the craniovertebral junction remains one of the major challenges for neurosurgeons, because of issues such as the complex functional anatomy and vascular structures. We present three cases in which the high cervical lateral approach was used to safely remove the cystic retro-odontoid pseudotumor, not associated with rheumatoid arthritis, severely compressing the spinal cord. The mean age of patients was 74.7 years (range, 73–77 years). Neurological condition was assessed based on the neurosurgical cervical spine scale. A high cervical lateral approach was applied to remove the pseudotumor safely. Mean duration of follow-up after surgery was 21.3 months (range, 18–24 months). Mean recovery rate was 77.8%. All patients showed acceptable or satisfactory functional recovery, although one patient (Case 2) developed mild paralysis of the facial and spinal accessory nerve on the surgical approach side, but that completely recovered within about 1 month after surgery. Postoperative assessment at the recent follow-up suggested no significant aggravation of neck movement. This technical note suggests that the high cervical lateral approach can be considered as a surgical option for cystic retro-odontoid pseudotumor, not associated with rheumatoid arthritis, severely compressing the spinal cord. Safe management of the vertebral artery is one of the key considerations.

Anterior and Posterior Segmental Decompression and Fusion for Severely Localized Ossification of the Posterior Longitudinal Ligament of the Cervical Spine: Technical Note

The surgical strategy for severely localized ossification of the posterior longitudinal ligament (OPLL) of the cervical spine is still not straightforward. We describe the surgical technique of extended anterior cervical discectomy and fusion (ACDF) with partial resection of OPLL followed by posterior cervical segmental decompression and fusion (PCDF). This study investigated five patients with severely localized OPLL with an occupying ratio more than 60%. Extended ACDF comprising a modified technique with a trans-unco-discal approach and partial oblique corpectomy was first attempted to achieve neural decompression of the spinal cord and nerve roots at the most prominent level of the OPLL. The OPLL was partially resected to reduce the axial occupying ratio or ensure that the OPLL did not exceed the imaginary line between the midpoint between C2 and C7 on sagittal images. PCDF was then performed to achieve satisfactory decompression of neural elements and cervical stability. One patient underwent one-stage surgery and the remaining four patients underwent two-stage surgery. No patients received spinal cerebrospinal fluid (CSF) drainage and demonstrated CSF leakage after surgery. All patients showed acceptable or satisfactory functional recovery. No instrumentation-related complications were encountered. Radiological analysis demonstrated that all except one patient (OPLL associated with ankylosing spinal hyperostosis) revealed improvements in local angle, C2–7 angle and cervical tilt angle. This anterior and posterior segmental decompression and fusion for severely localized OPLL of the cervical spine remains technically demanding in some parts, but can offer satisfactory decompression of neural elements and stabilization of the cervical spine when applied appropriately.

Posterior instrumented fusion surgery for adult spinal deformity: Correction rate and total balance

Background:

The primary radiological goal of surgery for adult spinal deformity (ASD) is the restoration of lumbar lordosis (LL). Radiological parameters were analyzed to determine the surgical indications for ASD using posterior side-loading spinal instrumentation system.

Materials and Methods:

This retrospective study included 31 patients of ASD who underwent posterior instrumented fusion surgery. Imaging parameters included spinal tilt angle (STA), LL, and thoracic kyphosis (TK). The ideal LL was estimated based on the normal value.

Results:

Of 16 patients with sagittal imbalance, 10 patients demonstrated sagittal balance postoperatively. All six patients with frontal imbalance showed frontal balance postoperatively. STA improvement well correlated with change of LL. On univariate analysis, preoperative TK was significantly associated with preoperative sagittal imbalance and postoperative lack of LL with postoperative sagittal imbalance.

Conclusions:

The surgical concept of ASD focusing on correction of LL was demonstrated. Although the surgery of ASD is still challenging, posterior instrumented fusion surgery using posterior side-loading system may be well applied for mild or moderate ASD without hyper-TK. The posterior side-loading system is practical and can be one of the surgical choices.

Estimate of Fukushima-derived radiocaesium in the North Pacific Ocean in summer 2012

Distributions of radiocaesium (134Cs and 137Cs) derived from the Tokyo Electric Power Company (TEPCO) Fukushima Dai-ichi Nuclear Power Plant (FNPP1) accident in the North Pacific Ocean in the summer of 2012 were investigated. We have estimated the radiocaesium inventory in the surface layer using the optimal interpolation analysis and the subducted amount into the central mode water (CMW) by using vertical profiles of FNPP1-134Cs and mass balance analysis as the first approach. The inventory of the 134Cs in the surface layer in the North Pacific Ocean in August-December 2012 was estimated at 5.1 ± 0.9 PBq on 1 October 2012, which corresponds to 8.6 ± 1.5 PBq when it was decay corrected to the date of the FNPP1 accident, 11 March 2011. It was revealed that 56 ± 10% of the released 134Cs into the North Pacific Ocean, which was estimated at 15.3 ± 2.6 PBq, transported eastward in the surface layer in 2012. The amount of 134Cs subducted in the CMW was estimated to be 2.5 ± 0.9 PBq based on the mass balance among the three domains of the surface layer, subtropical mode water, and CMW.

Safety and accuracy of spinal instrumentation surgery in a hybrid operating room with an intraoperative cone-beam computed tomography

Although spinal instrumentation technique has undergone revolutionary progress over the past few decades, it may still carry significant surgery-related risks. The purpose of the present study was to assess the radiological accuracy of spinal screw instrumentation using a hybrid operating room (OR) and quantify the related radiation exposure. This retrospective study included 33 cases of complex spine fusion surgeries that were conducted using a hybrid OR with a flat panel detector (FPD) angiography system. Twelve cases (36.4%) were cervical, and 21 (63.6%) were thoracolumbar. The average number of spine fusion levels was 3 and 4.8, respectively, at the cervical and thoracolumbar spine levels. A FPD angiography system was used for intraoperative cone-beam computed tomography (CBCT) to obtain multi-slice spine images. All operations were conducted under optimized radiation shielding. Entrance surface doses (ESDs) and exposure times were recorded in all cases. A total of 313 screws were placed. Satisfactory screw insertion could be achieved in all cases with safe screw placement in 97.4% and acceptable placement in 2.6%. None of the cases showed any significant anatomical violation by the screws. The radiation exposure to the patients was absolutely consistent with the desired ESD value, and that to the surgeons, under the annual dose limit. These results suggest that the hybrid OR with a FPD angiography system is helpful to achieve safe and precise spinal fusion surgery, especially in complex cases.

Novel biallelic SZT2 mutations in 3 cases of early-onset epileptic encephalopathy

The seizure threshold 2 (SZT2) gene encodes a large, highly conserved protein that is associated with epileptogenesis. In mice, Szt2 is abundantly expressed in the central nervous system. Recently, biallelic SZT2 mutations were found in 7 patients (from 5 families) presenting with epileptic encephalopathy with dysmorphic features and/or non-syndromic intellectual disabilities. In this study, we identified by whole-exome sequencing compound heterozygous SZT2 mutations in 3 patients with early-onset epileptic encephalopathies. Six novel SZT2 mutations were found, including 3 truncating, 1 splice site and 2 missense mutations. The splice-site mutation resulted in skipping of exon 20 and was associated with a premature stop codon. All individuals presented with seizures, severe developmental delay and intellectual disabilities with high variability. Brain MRIs revealed a characteristic thick and short corpus callosum or a persistent cavum septum pellucidum in each of the 2 cases. Interestingly, in the third case, born to consanguineous parents, had unexpected compound heterozygous missense mutations. She showed microcephaly despite the other case and previous ones presenting with macrocephaly, suggesting that SZT2 mutations might affect head size.

Surgical Outcomes of Posterolateral Sulcus Approach for Spinal Intramedullary Tumors: Tumor Resection and Functional Preservation

BACKGROUND

Selection of the access myelotomy is a key issue in surgery for spinal intramedullary tumors. This study focused on surgical outcomes with the posterolateral sulcus (PLS) approach, equivalent to dorsal root entry zone myelotomy.

METHODS

This retrospective study of the 10-year period from 2007 to 2016 included 90 cases of spinal intramedullary lesions (99 operations). A PLS approach was indicated for intramedullary lesions situated laterally in the spinal cord showing no contact with the spinal cord surface. Neurological conditions before and after surgery were carefully assessed objectively.

RESULTS

A PLS approach was applied in 34 of the 99 operations (34.3%). Among 70 cases involving astrocytic tumor, ependymal tumor, cavernous malformation or hemangioblastoma, 23 cases (32.9%) were operated on using a PLS approach. Microscopically gross total or subtotal removal of the tumor was achieved in 18 of 23 cases (78.3%). These 18 cases demonstrated mild deterioration of motor function on the approach side early after surgery, but usually resolving within several months postoperatively. Average grade of the modified McCormick functional schema before surgery was maintained 6 months postoperatively. Average grade of the sensory pain scale before surgery was significantly improved by 6 months postoperatively. Segmental dysesthesia on the approach side unexpectedly remained in 2 of 18 cases (11.1%) even late after surgery.

CONCLUSIONS

These findings suggest that the PLS approach can provide direct access to tumors with minimal tissue damage, when applied appropriately after careful case selection.

Benefits and Limitations of Indocyanine Green Fluorescent Image-Guided Surgery for Spinal Intramedullary Tumors

BACKGROUND

Intraoperative image guidance using near-infrared indocyanine green videoangiography (ICG-VA) has been used to provide real-time angiographic images during vascular or brain tumor surgery, and it is also being used for spine surgery.

OBJECTIVE

To further investigate the benefits and limitations of ICG-VA image-guided surgery for spinal intramedullary tumors through retrospective study.

METHODS

ICG-VA was used in 48 cases that were treated surgically over the past 5 yr. The pathological diagnoses of the tumors included astrocytic tumor, ependymal tumor, cavernous malformation, and hemangioblastoma.

RESULTS

Localization of normal spinal arteries and veins on the dorsal surface of the spinal cord helped the surgeons determine the length or point of myelotomy. Well-demarcated tumor stain was recognized in limited cases of anaplastic or highly vascularized tumors, whereas the location of cavernous malformation was recognized as an avascular area on the dorsal surface of the spinal cord. Feeding arteries and tumor stain were well differentiated from draining veins in dorsal hemangioblastomas, but not in intramedullary deep-seated or ventral tumors. The preservation of small perforating branches of the anterior spinal artery after successful resection of the tumor could be well visualized.

CONCLUSION

ICG-VA can provide real-time information about vascular flow dynamics during the surgery of spinal intramedullary tumors, and it may help surgeons localize the normal circulation of the spinal cord, as well as the feeding arteries and draining veins, especially in highly vascular tumors. However, the benefits of intraoperative ICG-VA might be limited for intramedullary deep-seated or ventral tumors.

Influence of prevertebral soft tissue swelling on dysphagia after anterior cervical discectomy and fusion using a rectangular titanium stand-alone cage

Background:

Postoperative oropharyngeal complications such as dysphagia after anterior cervical spine surgery are some of the least discussed surgery-related complications. The purpose of this retrospective study is to investigate the incidence and possible risk factors for 30-day postoperative dysphagia after anterior cervical discectomy and fusion (ACDF).

Materials and Methods:

This study included 152 consecutive patients who underwent 1- or 2-level ACDF using a rectangular titanium stand-alone cage in our institutes. Surgery-related dysphagia early after surgery was analyzed based on hospital charts. Radiological evaluation of prevertebral soft tissue swelling (PSTS) was performed by comparing plain lateral radiographs of the cervical spine before surgery with those after surgery. The percentage of PSTS (%PSTS) was defined by retropharyngeal soft tissue diameter divided by vertebral diameter. Positive %PSTS was determined when %PSTS exceeded its mean + 2 standard deviations.

Results:

Twelve patients (7.9%) demonstrated prolonged symptoms of dysphagia within 30-day postoperatively. All patients eventually demonstrated satisfactory or acceptable recovery late after surgery, except one case of hypoglossal nerve palsy. %PSTS was significantly highest early after surgery and returned to presurgical levels within 30 days after surgery. Statistical analysis suggested that the positive %PSTS at C3 or C4 level early after surgery was significantly associated with the occurrence of postoperative dysphagia.

Conclusions:

Although the possible reasons for postoperative dysphagia may not only be multifactorial but also be highly surgeon-dependent, such a complication is still underestimated and needs to be carefully resolved. %PSTS appeared to be easy and reliable index to judge the possible risk of postoperative dysphagia.

A minimum 2-year comparative study of autologous cancellous bone grafting versus beta-tricalcium phosphate in anterior cervical discectomy and fusion using a rectangular titanium stand-alone cage

Although titanium stand-alone cages are commonly used in anterior cervical discectomy and fusion (ACDF), there are several concerns such as cage subsidence after surgery. The efficacy of β-tricalcium phosphate (β-TCP) granules as a packing material in 1- or 2-level ACDF using a rectangular titanium stand-alone cage is not fully understood. The purpose of this study is to investigate the validity of rectangular titanium stand-alone cages in 1- and 2-level ACDF with β-TCP. This retrospective study included 55 consecutive patients who underwent ACDF with autologous iliac cancellous bone grafting and 45 consecutive patients with β-TCP grafting. All patients completed at least 2-year postoperative follow-up. Univariate and multivariate analyses were performed to examine the associations between study variables and nonunion after surgery. Significant neurological recovery after surgery was obtained in both groups. Cage subsidence was noted in 14 of 72 cages (19.4 %) in the autograft group and 12 of 64 cages (18.8 %) in the β-TCP group. A total of 66 cages (91.7 %) in the autograft group showed osseous or partial union, and 58 cages (90.6 %) in the β-TCP group showed osseous or partial union by 2 years after surgery. There were no significant differences in cage subsidence and the bony fusion rate between the two groups. Multivariate analysis using a logistic regression model showed that fusion level at C6/7, 2-level fusion, and cage subsidence of grades 2-3 were significantly associated with nonunion at 2 years after surgery. Although an acceptable surgical outcome with negligible complication appears to justify the use of rectangular titanium stand-alone cages in 1- and 2-level ACDF with β-TCP, cage subsidence after surgery needs to be avoided to achieve acceptable bony fusion at the fused segments. Fusion level at C6/7 or 2-level fusion may be another risk factor of nonunion.

Posterolateral approach for spinal intradural meningioma with ventral attachment

Background:

Spinal meningioma with ventral attachment is a challenging pathology. Several technical modifications have been proposed to secure safe and precise resection of these tumors.

Materials and Methods:

This retrospective study focused on the precise and safe surgery of spinal meningiomas with strictly ventral attachment of cervical or thoracic spine. The surgical technique included a lateral oblique position for the patient, laminectomy with unilateral medial facetectomy on the tumor side, and spinal cord rotation with the dentate ligament. The neurological status of patients was assessed using the modified McCormick functional schema (mMFS) and sensory pain scale (SPS) before and at least 3 months after surgery. Patients were followed-up for a mean of 23.7 months. Tumor removal was graded using the Simpson grade for removal of meningiomas, and the extent of excision was confirmed using early postoperative magnetic resonance imaging.

Results:

Simpson grade 1 or 2 resections were achieved in all cases. No major surgery-related complications were encountered, postoperatively. The mean mMFS score before surgery was 3.1, improving significantly to 1.7 after surgery (P < 0.05). The mean SPS score before surgery was 2.4, improving significantly to 1.6 after surgery (P < 0.05).

Conclusions:

This surgical technique offers a posterolateral surgical corridor to the ventral canal of both cervical and thoracic spine. The present preliminary analysis suggests that functional outcomes were satisfactory with minimal surgery-related complications, although considerable surgical experience is needed to achieve a high level of surgical confidence.

Prediction of the efficacy of surgical intervention in patients with cervical myelopathy by using diffusion tensor 3T-magnetic resonance imaging parameters

Background:

The clinical significance of diffusion tensor (DT) magnetic resonance imaging (MRI) parameters was analyzed to predict postoperative functional recovery in patients with cervical myelopathy.

Materials and Methods:

Sixteen patients with cervical myelopathy caused by cervical spondylosis, disk herniation or ossification of the posterior longitudinal ligament who underwent surgical intervention in our institute were enrolled in this retrospective study. There were 7 men and 9 women, with a mean age of 62.8 years. Clinical assessment was done before surgery and at least 3 months after surgery. All patients underwent whole-body 3.0-Tesla MRI before surgery. DT images (DTIs) were obtained using a single-shot fast spin-echo-based sequence. Mean values of mean diffusivity (MD) and fractional anisotropy (FA) at 6 disk levels of the cervical spine were measured using manual setting of regions of interest. The MD and FA values at the most compressed part were analyzed. Absolute MD and FA values at the most compressed spinal level in patients were transformed into the normalized values with a z-score analysis.

Results:

MD-z may decrease with the severity of cervical myelopathy. Receiver operating characteristic analysis of MD-z and FA-z suggested that both MD-z and FA-z have clinical validity for predicting the efficacy of surgical intervention, but MD-z was considered to be the most appropriate value to predict the efficacy of surgery.

Conclusions:

DTIs may be a promising modality to predict functional recovery after surgery. MD changes may reflect spinal cord condition and its reversibility.

Qualitative analysis of spinal intramedullary lesions using PET/CT

OBJECT Although the usefulness of PET for brain lesions has been established, few reports have examined the use of PET for spinal intramedullary lesions. This study investigated the diagnostic utility of PET/CT for spinal intramedullary lesions. METHODS l-[methyl-¹¹C]-methionine (MET)- or [¹⁸F]-fluorodeoxyglucose (FDG)-PET/CT was performed in 26 patients with spinal intramedullary lesions. The region of interest (ROI) within the spinal cord parenchyma was placed manually in the axial plane. Maximum pixel counts in the ROIs were normalized to the maximum standardized uptake value (SUV_max) using subject body weight. For FDG-PET the SUV_max was corrected for lean body mass (SUL_max) to exclude any influence of the patient's body shape. Each SUV was analyzed based on histopathological results after surgery. The diagnostic validity of the SUV was further compared with the tumor proliferation index using the MIB-1 monoclonal antibody (MIB-1 index). RESULTS A total of 16 patients underwent both FDG-PET and MET-PET, and the remaining 10 patients underwent either FDG-PET or MET-PET. Pathological diagnoses included high-grade malignancy such as glioblastoma multiforme, anaplastic astrocytoma, or anaplastic ependymoma in 5 patients; low-grade malignancy such as hemangioblastoma, diffuse astrocytoma, or ependymoma in 12 patients; and nonneoplastic lesion including cavernous malformation in 9 patients. Both FDG and MET accumulated significantly in high-grade malignancy, and the SUL_max and SUV_max correlated with the tumor proliferation index. Therapeutic response after chemotherapy or radiation in high-grade malignancy was well monitored. However, a significant difference in SUL_max and SUV_max for FDG-PET and MET-PET was not evident between low-grade malignancy and nonneoplastic lesions. CONCLUSIONS Spinal PET/CT using FDG or MET for spinal intramedullary lesions appears useful and practical, particularly for tumors with high-grade malignancy. Differentiation of tumors with low-grade malignancy from nonneoplastic lesions may still prove difficult. Further technological refinement, including the selection of radiotracer or analysis evaluation methods, is needed.

Surgical management of spinal intramedullary tumors: radical and safe strategy for benign tumors

Surgery for spinal intramedullary tumors remains one of the major challenges for neurosurgeons, due to their relative infrequency, unknown natural history, and surgical difficulty. We are sure that safe and precise resection of spinal intramedullary tumors, particularly encapsulated benign tumors, can result in acceptable or satisfactory postoperative outcomes. General surgical concepts and strategies, technical consideration, and functional outcomes after surgery are discussed with illustrative cases of spinal intramedullary benign tumors such as ependymoma, cavernous malformation, and hemangioblastoma. Selection of a posterior median sulcus, posterolateral sulcus, or direct transpial approach was determined based on the preoperative imaging diagnosis and careful inspection of the spinal cord surface. Tumor-cord interface was meticulously delineated in cases of benign encapsulated tumors. Our retrospective functional analysis of 24 consecutive cases of spinal intramedullary ependymoma followed for at least 6 months postoperatively demonstrated a mean grade on the modified McCormick functional schema of 1.8 before surgery, deteriorating significantly to 2.6 early after surgery (< 1 month after surgery), and finally returning to 1.7 in the late postoperative period (> 6 months after surgery). The risk of functional deterioration after surgery should be taken into serious consideration. Functional deterioration after surgery, including neuropathic pain even long after surgery, significantly affects patient quality of life. Better balance between tumor control and functional preservation can be achieved not only by the surgical technique or expertise, but also by intraoperative neurophysiological monitoring, vascular image guidance, and postoperative supportive care. Quality of life after surgery should inarguably be given top priority.

Surgical management of solitary nerve sheath tumors of the cervical spine: a retrospective case analysis based on tumor location and extension

Complete resection of spinal nerve sheath tumors (NSTs) does not always result in significant neurological deficit. The purpose of this retrospective case analysis was to discuss the optimal surgical strategy for spinal NST of the cervical spine. Twenty-four patients who underwent surgery for solitary cervical NST over the past decade were included in this retrospective study. Patients with neurofibromatosis or schwannomatosis were excluded. Seventeen of the 24 cases (70.8%) showed extradural dumbbell extension, most frequently at the C1 or C2 vertebral level. Neurological condition was assessed using the modified McCormick functional schema and sensory pain scale. Total removal of the tumor was achieved in 20 of 24 cases (83.3%). Staged surgery using combined anterior and posterior approaches was applied for 2 of 17 cases with extradural dumbbell extension. Tumor involvement with nerve root fibers critical for upper extremity function (C5–C8) was recognized in 6 of 24 cases (25.0%), with complete resection in all 6 cases. Final assessment of neurological function revealed satisfactory or acceptable recovery in all 6 patients. Spinal NSTs with extradural dumbbell extension are a common condition in the cervical spine. Complete removal of spinal NST of the cervical spine may carry a risk of permanent neurological deficit, but such sequelae appeared to be the exception in the present case analysis. A radical and safe surgical strategy, including staged surgery combining anterior and posterior approaches, should be tailored to the individual case.

Surgical management of spinal meningiomas: A retrospective case analysis based on preoperative surgical grade

Background:

Although spinal meningiomas respond favorably to surgical excision, their surgical management is impacted by several factors. This study utilized a surgery-based grading system to discuss the optimal surgical strategy.

Methods:

Twenty-three consecutive patients who underwent surgery for spinal meningiomas were included in this retrospective study. The patients’ neurological condition was assessed using the modified McCormick functional schema (mMFS) and sensory pain scale (SPS), and tumor removal was assessed using Simpson grade. Major factors contributing to surgical difficulty included; tumor size, extent/severity of cord compression, location of tumor attachment, spinal level, and anatomical relationships plus tumor extending in a dumbbell shape and local postoperative recurrence.

Results:

Fifteen cases were classified as ventral attachment (65.2%). There were two dumbbell-shaped tumors and three local recurrences at the primary site. Simpson grade 1 or 2 resections were performed in 18 of 20 cases (90%) with preoperative surgical grades 0 to 3. Simpson grade 4 resections were achieved in all three cases with preoperative surgical grades 4 to 5. Overall neurological assessment after surgery revealed the satisfactory or acceptable recovery on mMFS and SPS analysis.

Conclusions:

Lower preoperative grade yielded better results, while the higher the preoperative grade, the more likely tumor was insufficiently removed. A preoperative surgical grading system appeared to be helpful when considering the surgical strategy. Ventral meningiomas could be safely resected via the posterolateral or lateral approach using technical modifications. Recurrent tumors, especially with ventral attachment, were hard to resolve, and primary surgery appears to be important.

A prospective, randomized, double-blind, controlled trial on the efficacy of carbon dioxide insufflation in gastric endoscopic submucosal dissection

BACKGROUND AND STUDY AIMS

Carbon dioxide (CO2) insufflation is expected to be safe and effective in endoscopic submucosal dissection (ESD) as well as in other endoscopic procedures. The present study aimed to clarify the usefulness and safety of CO2 insufflation in gastric ESD.

PATIENTS AND METHODS

A total of 102 consecutive patients were randomly assigned to CO2 insufflation (CO2 group, n = 54) or air insufflation (Air group, n = 48). Abdominal pain and distension were chronologically recorded on a 100-mm visual analog scale (VAS). The volume of residual gas in the digestive tract was measured by computed tomography performed immediately after ESD.

RESULTS

Abdominal pain on a 100-mm VAS in the CO2 vs. Air group was 4 vs. 3 immediately after ESD, 4 vs. 4 one hour after the procedure, 3 vs. 3 three hours after the procedure, and 1 vs. 4 the next morning, showing no difference between the groups. In addition, there was no difference in abdominal distension on the 100-mm VAS over the time course of the study. The volume of residual gas in the digestive tract in the CO2 group was significantly smaller than that in the Air group (643 mL vs. 1037 mL, P < 0.001). The dose of sedative drugs did not differ between the groups. Neither the incidences of complications nor clinical courses differed between the groups.

CONCLUSIONS

Compared with air insufflation, CO2 insufflation during gastric ESD significantly reduced the volume of residual gas in the digestive tract but not the VAS score of abdominal pain and distension.

Posterolateral sulcus approach for spinal intramedullary tumor of lateral location: technical note

Posterolateral sulcus (PLS) approach of the spinal cord, being equivalent to the dorsal root entry zone myelotomy, may offer the satisfactory exposure of the spinal intramedullary tumor if applied appropriately. Eight consecutive patients with spinal intramedullary tumors of lateral location underwent the surgery of PLS approach in our institute. There were 6 male and 2 female patients, ranging in age from 34 to 72 years (mean, 57 years). PLS approach was indicated for the intramedullary tumor situated laterally in the spinal cord and that do not contact the posterior or lateral surfaces on magnetic resonance (MR) images before surgery. Total removal of the tumor was achieved in 6 cases except of 2 cases of anaplastic astrocytoma. All 6 patients with total removal of the tumor demonstrated the modest or mild deterioration of motor function on the approach side early after surgery, which resolved within 1 month after surgery. Average grade of the modified McCormick functional schema was 3.5 before surgery and improved to 3.0 at 3 months after surgery. These 6 patients demonstrated satisfactory pain relief early after surgery. Average grade of the sensory pain scale was 2.7 before surgery and improved to 1.7 at 3 months after surgery. PLS approach can be one of the surgical choices to the spinal intramedullary tumors, if applied appropriately. Better indication for PLS approach may be the tumors of the uneven location within the spinal cord associated with moderate or severe local pain.

C2 nerve root resection to achieve safe and wide exposure of lateral atlantoaxial joints in posterior C1-2 instrumented fixation: technical note

Posterior atlantoaxial (C1-2) fixation with individual screw placement in C1 and C2 has been one of the technical options to treat C1-2 subluxation or instability. In the present study, we demonstrate the surgical technique of C2 nerve root resection to avoid the troublesome bleeding from the perivertebral venous plexus and achieve full exposure of the lateral C1-2 joints. The present study includes a series of 16 consecutive patients who underwent posterior C1-2 instrumented fixation with individual screw placement in C1 and C2. All patients underwent unilateral or bilateral C2 nerve root resection at the sensory ganglion. Screw malposition resulting in vascular or neural injury was not encountered. Sensory pain scale analysis indicated that the mean score before surgery was 2.4, which significantly improved to 1.4 after surgery. No patients reported allodynia or C2 distribution neuropathic pain during the follow-up. C2 nerve root resection resulted in early postoperative dysesthesia in all 16 patients; however, neurological examination during the follow-up revealed that only 12.5% of all analyzed patients did not demonstrate satisfactory recovery of C2 sensory disturbance. Postoperative radiologic analysis revealed solid osseous or partial fusion at the lateral C1-2 joints in all cases during the follow-up. No case demonstrated non-union with pseudoarthrosis. Although C2 nerve root resection is still under debate and not fully justified, the present study suggests that C2 nerve root resection does not always result in significant morbidity and can be an option for surgical resolution to achieve safe and wide exposure of lateral C1-2 joints.

Intraoperative assessment of spinal vascular flow in the surgery of spinal intramedullary tumors using indocyanine green videoangiography

Background:

The authors demonstrate the utility of indocyanine green videoangiography (ICG-VA) for intraoperative vascular flow assessment in the surgery of a variety of spinal intramedullary tumors to achieve an additional level of safety as well as precision with the surgical procedure.

Methods:

Fourteen patients with spinal intramedullary tumors (nine cervical and five thoracic) operated on between August 2011 and April 2013 were included in the present study. A fluorescence surgical microscope was used to perform ICG-VA after standard exposure of the lesion to assess the dynamic flow of the spinal microvasculature.

Results:

Twenty-seven ICG-VA injections were performed in 14 cases. Pathological diagnosis of the tumors included ependymoa, astrocytoma, cavernous malformation, or hemagioblastoma. There were no complications or side-effects related to ICG-VA. Intraoperative ICG-VA provided dynamic flow images of the spinal microvasculature in accordance with the progress of surgical procedures. Angiographic images could be divided into arterial, capillary, and venous phases. All angiographic images were well integrated into the microscopic view. The utility of ICG-VA could be summarized into three categories: (1) Localization of normal spinal arteries and veins, (2) assessment of posterior spinal venous circulation, and (3) differentiation of feeding arteries, tumor, and draining veins.

Conclusions:

Intraoperative vascular flow assessment using ICG-VA was easy, repeatable, and practical without any significant procedure-related risks. ICG-VA can be used for careful analysis of spinal microvascular flow or anatomical orientation, which is necessary to ensure safe and precise resection of spinal intramedullary tumors.

Intermittent breath holding during moderate bicycle exercise provokes consistent changes in muscle oxygenation and greater blood lactate response

AIM

This study examined the effect of intermittent breath holding (IBH) on physiological response, including oxygenation in working muscle, to moderate-intensity exercise.

METHODS

Thirteen men performed bicycle exercise for 5 min at 65% of peak oxygen uptake with normal breathing (NB) and with IBH. Muscle oxygenation, concentration changes of oxyhemoglobin (ΔOxy-Hb), deoxyhemoglobin (ΔDeoxy-Hb) and total hemoglobin (ΔTotal-Hb), in the right vastus lateralis were continuously monitored using near-infrared spectroscopy (NIRS). Finger capillary blood samples were taken after exercise for analyzing blood lactate concentration (BLa).

RESULTS

NIRS parameters showed acute changes to each BH episode in the IBH condition (Total-Hb and ΔOxy-Hb decreased, ΔDeoxy-Hb increased). Accordingly, in the IBH condition, ΔOxy-Hb was lower (P<0.05) and ΔDeoxy-Hb was higher (P<0.05) compared to that in the NB condition, whereas there was no difference in ΔTotal-Hb in the both conditions. BLa levels were greater (P<0.05) in the IBH condition compare to the NB condition.

CONCLUSION

These results suggest that IBH during moderate-intensity exercise provokes consistent changes in muscle oxygenation, leading to lower tissue oxygenation. Our data also indicate that exercise with IBH induces higher BLa.

Primary intramedullary Langerhans cell histiocytosis of the thoracic spinal cord

A 28-year-old male presented with a rare case of primary intramedullary spinal Langerhans cell histiocytosis (LCH) manifesting as the chief complaint of a 6-month history of gait disturbance and back pain, and difficulty with sphincter control. Serial T2-weighted magnetic resonance imaging of the thoracic spine revealed enlargement and intramedullary hyperintensity of the spinal cord at T2 to T4. Biopsy of the lesion was performed. Histological examination of the biopsy specimens verified vascular proliferation and remarkable infiltration of histiocytes that were positive for CD1a, suggesting a diagnosis compatible with LCH. The patient was treated successfully by steroid pulse therapy. LCH is a rare disease that occurs mainly in children and may cause a broad range of manifestations, from a single osseous lesion to multiple lesions involving more than one organ or system. The present case illustrates the unexpected occurrence and important differential diagnosis of primary intramedullary spinal LCH of the thoracic spine in adult patients presenting with progressive paraparesis and back pain.

Significant relationship between local angle at fused segments and C2-7 angle: Average duration of longer than 20 years after anterior cervical discectomy and fusion

Background:

The authors have focused their attention to the radiological durability of cervical sagittal alignment after anterior cervical discectomy and fusion (ACDF) using autologous bone grafting.

Materials and Methods:

Among the patients who underwent ACDF with trans-unco-discal (TUD) approach between 1976 and 1997, 22 patients (16 males and 6 females) made return visits for a clinical evaluation. Patients with trauma or previously treated by anterior cervical fusion or by posterior decompression were excluded from the present study. Clinical evaluation included adjacent segment degeneration (ASD), osseous fusion, local angle at the fused segments and C2-7 angle of cervical spine.

Results:

The duration after ACDF ranged from 13 to 34 years with an average of 21.3 ± 7.0 years. A single level fusion was done on 8 patients, 2 levels on 11 patients, 3 levels on 2 patients, and 4 levels on 1 patient. Imaging studies indicated that 12 of the 22 patients (54.5%) were graded as having symptomatic ASD. Osseous bony fusion at ACDF was recognized in all cases. None of the patients demonstrated kyphotic malalignment of the cervical spine. Average degrees of local angle at the fused segments and the C2-7 angle were 7.06 and 17.6, respectively. Statistical analysis indicated a significant relationship between the local at the fused segments and C2-7 angles.

Conclusions:

Sagittal alignment of the cervical spine was durable long after ACDF when the local angle at the fused segments was well stabilized.

Normal variation of diffusion tensor parameters of the spinal cord in healthy subjects at 3.0-Tesla

AIMS

The purposes of the present study were to clarify the normal variation and to determine the normal reference values of diffusion tensor (DT) parameters (mean diffusivity [MD] and fractional anisotropy [FA]) of the spinal cord in single-shot fast spin-echo-based sequence at 3.0-Tesla (3T).

MATERIALS AND METHODS

Thirty healthy subjects (mean age = 44.2 years, range = 20-72 years) were enrolled for this study. Mean values of MD and FA in six spinal levels (C2/3, C3/4, C4/5, C5/6, C6/7, and C7/Th1) were measured. Mean values, variances, and distributions of the MD and FA in each spinal level were analyzed. Age-dependent change of MD and FA as well as correlation between MD and FA was also analyzed.

RESULTS

At all spinal levels, the values can be considered to be Gaussian distribution in MD but not in FA. A significant statistical negative correlation was observed between aging and the values of MD (r = 0.429, P = 0.018), but insignificant between the values of FA (P = 0.234). A slight significant statistical negative correlation was observed between the values of MD and FA (r = 0.156, P = 0.037). One way repeated measures analysis of variance indicated the significant difference between the spinal levels in both MD (P = 0.003) and FA (P < 0.0001).

CONCLUSIONS

The analyzed data in the present study would be helpful for comparison when investigating the spinal condition of spinal disorders.

A dipole mode in the tropical Indian Ocean

For the tropical Pacific and Atlantic oceans, internal modes of variability that lead to climatic oscillations have been recognized, but in the Indian Ocean region a similar ocean-atmosphere interaction causing interannual climate variability has not yet been found. Here we report an analysis of observational data over the past 40 years, showing a dipole mode in the Indian Ocean: a pattern of internal variability with anomalously low sea surface temperatures off Sumatra and high sea surface temperatures in the western Indian Ocean, with accompanying wind and precipitation anomalies. The spatio-temporal links between sea surface temperatures and winds reveal a strong coupling through the precipitation field and ocean dynamics. This air-sea interaction process is unique and inherent in the Indian Ocean, and is shown to be independent of the El Niño/Southern Oscillation. The discovery of this dipole mode that accounts for about 12% of the sea surface temperature variability in the Indian Ocean--and, in its active years, also causes severe rainfall in eastern Africa and droughts in Indonesia--brightens the prospects for a long-term forecast of rainfall anomalies in the affected countries.

Separation of pygmy dipole and M1 resonances in 90Zr by a high-resolution inelastic proton scattering near 0°

A high-resolution measurement of inelastic proton scattering off (90)Zr near 0° was performed at 295 MeV with a focus on a pronounced strength previously reported in the low-energy tail of giant dipole resonance. A forest of fine structure was observed in the excitation energy region 7-12 MeV. A multipole decomposition analysis of the angular distribution for the forest was carried out using the ECIS95 distorted-wave Born approximation code with the Hartree-Fock plus random-phase approximation model of E1 and M1 transition densities and inclusion of E1 Coulomb excitation. The analysis separated pygmy dipole and M1 resonances in the forest at E(PDR)=9.15±0.18 MeV with Γ(PDR)=2.91±0.64 MeV and at E(M1)=9.53±0.06 MeV with Γ(M1)=2.70±0.17 MeV in the Lorentzian function, respectively. The B(E1)↑ value for pygmy dipole resonance over 7-11 MeV is 0.75±0.08 e(2)fm(2), which corresponds to 2.1±0.2% of the Thomas-Reiche-Kuhn sum rule.

A pilot study to assess mediastinal emphysema after esophageal endoscopic submucosal dissection with carbon dioxide insufflation

BACKGROUND AND AIMS

Mediastinal emphysema sometimes develops following esophageal endoscopic submucosal dissection (ESD) without perforation because the esophagus has no serosa. Carbon dioxide (CO2) insufflation during esophageal ESD may reduce the incidence of mediastinal emphysema. The aim of the present study was to compare the incidence and severity of post-ESD mediastinal emphysema in patients receiving CO2 insufflation vs. standard air insufflation during esophageal ESD.

PATIENTS AND METHODS

A total of 27 patients who had undergone esophageal ESD with insufflation of CO2 between July 2009 and March 2010 were enrolled in this study (CO2 group). Another 105 patients who had undergone esophageal ESD with air insufflation between March 2004 and May 2009 were included as historical controls (air group). Multi-detector row computed tomography (MDCT) was carried out immediately after ESD. A conventional chest radiograph was taken the next day. Mediastinal emphysema findings on MDCT and radiography were compared between the groups.

RESULTS

Mediastinal emphysema detected by chest radiography was 0 % in the CO2 group vs. 6.6 % in the air group (n.s.). Mediastinal emphysema on MDCT was significantly less frequent in the CO2 group compared with the air group (30 % vs. 63 %; P = 0.002). The severity of mediastinal emphysema also tended to be lower in the CO2 group.

CONCLUSIONS

Whereas mediastinal emphysema detected by radiography is not so common, MDCT immediately after ESD revealed a certain prevalence of post-ESD mediastinal emphysema. Insufflation of CO2 rather than air during esophageal ESD significantly reduced postprocedural mediastinal emphysema. CO2 can be considered as insufflating gas for esophageal ESD.