Takayuki Imura

Dr. Takayuki Imura


Research Focus & Metrics

Academic Career Length

15Years (2012-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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15 September 2022 in Medicina
Verified
Journal Article
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YOYusuke OSHITA
Yusuke OSHITA
DMDaisuke Matsuyama
Daisuke Matsuyama
Daisuke SakaiDaisuke Sakai
Daisuke Sakai
Jordy ScholJordy Schol
Jordy Schol
ESEiki Shirasawa
Eiki Shirasawa
MWMasahiko Watanabe
Masahiko Watanabe
Background and Objectives: Intradiscal injection of Condoliase (chondroitin sulfate ABC endolyase), a glycosaminoglycan-degrading enzyme, is employed as a minimally invasive treatment for lumbar disc herniation (LDH) and represents a promising option between conservative treatment and surgical intervention. Since its 2018 approval in Japan, multiple single-site trails have highlighted its effectiveness, however, the effect of LDH types, and influences of patient age, sex, etc., on treatment success remains unclear. Moreover, data on teenagers and elderly patients has not been reported. In this retrospective multi-center study, we sought to classify prognostic factors for successful condoliase treatment for LDH and assess its effect on patients < 20 and ≥70 years old. Materials and Methods: We reviewed the records of 137 LDH patients treated through condoliase at four Japanese institutions and assessed its effectiveness among different age categories on alleviation of visual analog scale (VAS) of leg pain, low back pain and numbness, as well as ODI and JOA scores. Moreover, we divided them into either a “group-A” category if a ≥50% improvement in baseline leg pain VAS was observed or “group-N” if VAS leg pain improved 5° was also found to approach statical significance. In all age groups, average VAS scores showed improvement. However, 75% of adolescent patients showed deterioration in Pfirrmann classification following treatment. Conclusions: Intradiscal condoliase injection is an effective treatment for LDH, even in patients with large vertebral translation and posterior disc angles, regardless of age. However, since condoliase imposes a risk of progressing disc degeneration, its indication for younger patients remains controversial.

Verified
Journal Article
Open access
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TMTakayuki Matsunaga
Takayuki Matsunaga
MMMasayuki Miyagi
Masayuki Miyagi
TNToshiyuki Nakazawa
Toshiyuki Nakazawa
KMKosuke Murata
Kosuke Murata
AKAyumu Kawakubo
Ayumu Kawakubo
GIGen Inoue
Gen Inoue
Spinal sagittal malalignment due to vertebral fractures (VFs) induces low back pain (LBP) in patients with osteoporosis. This study aimed to elucidate spinal sagittal malalignment prevalence based on VF number and patient characteristics in individuals with osteoporosis and spinal sagittal malalignment. Spinal sagittal alignment, and VF number were measured in 259 patients with osteoporosis. Spinal sagittal malalignment was defined according to the SRS-Schwab classification of adult spinal deformity. Spinal sagittal malalignment prevalence was evaluated based on VF number. In patients without VFs, bone mineral density, bone turnover markers, LBP scores and health-related quality of life (HRQoL) scores of normal and sagittal malalignment groups were compared. In 205 of the 259 (79.2%) patients, spinal sagittal malalignment was detected. Sagittal malalignment prevalence in patients with 0, 1, or ≥2 VFs was 72.1%, 86.0%, and 86.3%, respectively. All LBP scores and some subscale of HRQoL scores in patients without VFs were significantly worse for the sagittal malalignment group than the normal alignment group (p < 0.05). The majority of patients with osteoporosis had spinal sagittal malalignment, including ≥70% of patients without VFs. Patients with spinal sagittal malalignment reported worse LBP and HRQoL. These findings suggest that spinal sagittal malalignment is a risk factor for LBP and poor HRQoL in patients with osteoporosis.

Verified
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MMMasayuki Miyagi
Masayuki Miyagi
KUKentaro Uchida
Kentaro Uchida
SISho Inoue
Sho Inoue
STShotaro Takano
Shotaro Takano
MNMitsufumi Nakawaki
Mitsufumi Nakawaki
GIGen Inoue
Gen Inoue
Animal studies suggest that pain-related-molecule upregulation in degenerated intervertebral discs (IVDs) potentially leads to low back pain (LBP). We hypothesized that IVD mechanical stress and axial loading contribute to discogenic LBP’s pathomechanism. This study aimed to elucidate the relationships among the clinical findings, radiographical findings, and pain-related-molecule expression in human degenerated IVDs. We harvested degenerated-IVD samples from 35 patients during spinal interbody fusion surgery. Pain-related molecules including tumor necrosis factor alpha (TNF-alpha), interleukin (IL)-6, calcitonin gene-related peptide (CGRP), microsomal prostaglandin E synthase-1 (mPGES1), and nerve growth factor (NGF) were determined. We also recorded preoperative clinical findings including body mass index (BMI), Oswestry Disability Index (ODI), and radiographical findings including the vacuum phenomenon (VP) and spinal instability. Furthermore, we compared pain-related-molecule expression between the VP (−) and (+) groups. BMI was significantly correlated with the ODI, CGRP, and mPGES-1 levels. In the VP (+) group, mPGES-1 levels were significantly higher than in the VP (−) group. Additionally, CGRP and mPGES-1 were significantly correlated. Axial loading and mechanical stress correlated with CGRP and mPGES-1 expression and not with inflammatory cytokine or NGF expression. Therefore, axial loading and mechanical stress upregulate CGRP and mPGES-1 in human degenerated IVDs, potentially leading to chronic discogenic LBP.

16 February 2023 in Medicina
Verified
Journal Article
Open access
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ESEiki Shirasawa
Eiki Shirasawa
WSWataru Saito
Wataru Saito
MMMasayuki Miyagi
Masayuki Miyagi
TITakayuki Imura
Takayuki Imura
TNToshiyuki Nakazawa
Toshiyuki Nakazawa
GIGen Inoue
Gen Inoue
Background and Objectives: Several predictive factors have been reportedly associated with intraoperative total blood loss (TBL) during posterior spinal fusion (PSF) for idiopathic scoliosis (IS). To reduce TBL, preoperative factors and interoperative factors are considered important. However, there are few reports that have evaluated bleeding patterns according to surgical stages. This study aimed to elucidate bleeding patterns at different surgical stages and determine the predictive factors for TBL during PSF surgery in patients with IS. Materials and Methods: Preoperative data, radiographic parameters, and intraoperative data of patients undergoing PSF for IS were retrospectively collected. We divided the patients into six stages: stage 1, exposure; stage 2, implant placement; stage 3, release; stage 4, correction; stage 5, bone grafting; and stage 6, closure; then we reviewed the blood loss and bleeding speed. Multiple-regression analysis was performed to generate a predictive formula for blood loss using preoperative and intraoperative factors, including blood loss at stage 1, as explanatory variables. Results: Forty-five patients (mean age: 17.6 years) were included. The mean operative time and TBL were 287.9 min and 756.5 mL, respectively. Blood loss was the highest at stage 3, followed by stage 4. Bleeding speed was the highest at stage 4, followed by stage 3. Bleeding speeds at stages 3 and 4 were significantly higher than those at stages 1 and 2. Preoperative Cobb angle, activated partial thromboplastin time (aPTT), number of fused vertebrae, and blood loss at stage 1 were significant contributing factors. Conclusions: Blood loss and bleeding speed during the release and correction stages were high. Specifically, bleeding speed significantly increased during and after the release procedure. The preoperative Cobb angle, aPTT, number of fixed vertebrae, and blood-loss volume during PSF were significantly associated with TBL. Our findings would be helpful for reducing TBL in patients undergoing PSF for IS.

5 June 2023 in Medicina
Verified
Journal Article
Open access
PDF file
MMMasayuki Miyagi
Masayuki Miyagi
WSWataru Saito
Wataru Saito
YMYusuke Mimura
Yusuke Mimura
TNToshiyuki Nakazawa
Toshiyuki Nakazawa
TITakayuki Imura
Takayuki Imura
GIGen Inoue
Gen Inoue
Background and objectives: Patients with neuromuscular diseases usually have progressive neuromuscular scoliosis (NMS), requiring invasive surgery. Some patients present with severe scoliosis at the time of consultation and are difficult to treat. Posterior spinal fusion (PSF) surgery combined with anterior release and pre- or intraoperative traction would be effective for severe spinal deformities but would be invasive. This study aimed to evaluate the outcomes of PSF-only surgery for patients with severe NMS with a Cobb angle > 100°. Materials and Methods: Thirty NMS patients (13 boys and 17 girls; mean age 13.8 years) who underwent PSF-only surgery for scoliosis with a Cobb angle > 100° were included. We reviewed the lower instrumented vertebra (LIV), duration of surgery, blood loss, perioperative complications, preoperative clinical findings, and radiographic findings, including Cobb angle and pelvic obliquity (PO) in the sitting position pre- and postoperatively. The correction rate and correction loss of the Cobb angle and PO were also calculated. Results: The mean duration of surgery was 338 min, intraoperative blood loss was 1440 mL, preoperative %VC was 34.1%, FEV1.0 (%) was 91.5%, and EF was 66.1%. There were eight cases of perioperative complications. The Cobb angle and PO correction rates were 48.5% and 42.0%, respectively. We divided the patients into two groups: the L5 group, in which the LIV was L5, and the pelvis group, in which the LIV was the pelvis. The duration of surgery and PO correction rate in the pelvis group were significantly higher than those in the L5 group. Conclusions: Patients with severe NMS demonstrated severe preoperative restrictive ventilatory impairments. PSF surgery without anterior release or any intra-/preoperative traction showed satisfactory outcomes, including acceptable scoliosis correction and improved clinical findings, even in patients with extremely severe NMS. Instrumentation and fusion to the pelvis for severe scoliosis in patients with NMS showed good PO correction and low correction loss of Cobb angle and PO, but a longer duration of surgery.

13 June 2012 in Journal of Medical Case Reports
Verified
Journal Article
Open access
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HFHisako Fujimaki
Hisako Fujimaki
TNToshiyuki Nakazawa
Toshiyuki Nakazawa
MUMasaki Ueno
Masaki Ueno
TITakayuki Imura
Takayuki Imura
WSWataru Saito
Wataru Saito
MTMasashi Takaso
Masashi Takaso
Introduction: Subarachnoid hemorrhages of spinal origin are extremely rare during pregnancy. We present the case of a patient with hemolytic anemia, elevated liver enzymes and low platelet count (the so-called HELLP syndrome), a potentially life-threatening complication associated with pre-eclampsia, who presented with an idiopathic spinal subarachnoid hematoma.Case presentation: At 29 gestational weeks, a 35-year-old Japanese woman was diagnosed with HELLP syndrome based on bilateral leg paralysis, diminished sensation and reflexes, and laboratory findings. The pregnancy was immediately brought to an end by Cesarean delivery. Post-operatively, an MRI scan revealed a space-occupying lesion in her thoracic spinal canal. Emergency decompression was followed by total laminectomy. A subarachnoid hematoma, partially extending as far as the ventral side, was removed. After thorough washing and drain placement, the operation was completed with the suturing of artificial dura mater. Eight months post-operatively, her lower extremity sensation had improved to a score of 8 out of 10, but improvements in her muscular strength were limited to slight gains in her toes. MRI scans taken two months post-operatively revealed edematous spinal cord changes within her medulla.Conclusions: A subarachnoid hematoma during pregnancy is extremely rare, possibly due to increased coagulability during pregnancy. However, this complication is potentially devastating should a clot compress the spinal cord or cauda equina. While several causes of hematoma have been proposed, we speculate that the factors underlying hemorrhagic diathesis in our case were the decreased platelet count characteristic of HELLP syndrome and vascular fragility due to elevated estrogen levels, in addition to increased abdominal pressure during pregnancy and pressure from the gravid uterus resulting in ruptured vessels around the spinal cord. In cases displaying a progressive lesion and severe neurological signs, prompt decompression is crucial.