1.Efficacy and Safety of a Novel Tapered-Tip Sheath System for Biliary-Lesion Tissue Sampling: A Randomized Controlled Trial
Hirokazu OKADA ; Norimitsu UZA ; Tomoaki MATSUMORI ; Hajime YAMAZAKI ; Muneji YASUDA ; Takeshi KUWADA ; Yoshihiro NISHIKAWA ; Takahisa MARUNO ; Masahiro SHIOKAWA ; Atsushi TAKAI ; Ken TAKAHASHI ; Akihisa FUKUDA ; Etsuro HATANO ; Sachiko MINAMIGUCHI ; Hiroshi SENO
Gut and Liver 2025;19(1):136-144
Background/Aims:
Pathological evaluation is crucial for diagnosing biliary lesions and determining appropriate treatment strategies. However, tissue sampling via the transpapillary route can be difficult. In this study, we aimed to assess the efficacy and safety of a novel tapered-tip sheath system for tissue sampling from biliary strictures.
Methods:
This single-center, randomized, parallel-group clinical trial included patients aged 20 to 85 years admitted to Kyoto University Hospital for biliary strictures. The patients were randomly assigned (1:1) to a new or conventional method group. The primary outcome was technical success of biopsy at the target bile duct using the assigned method, as determined in accordance with the intention-to-treat principle. Adverse events were assessed in all eligible patients.
Results:
Fifty-six patients were assessed for eligibility between September 2020 and March 2023; 50 patients were enrolled. The patients were randomly divided into the new (n=25) method group and the conventional (n=25) method group. Technical success was achieved in 96.0% (24/25) and 48.0% (12/25) of patients in the new and conventional method groups, respectively (risk ratio, 2.00; 95% confidence interval [CI], 1.32 to 3.03; risk difference, 48.0%; 95% CI, 27.0% to 69.0%; p<0.001). Adverse events occurred in 4.0% (1/25) and 36.0% (9/25) of patients in the new and conventional method groups, respectively (risk ratio, 0.11; 95% CI, 0.02 to 0.81; risk difference, –32.0%; 95% CI, –52.3% to –11.7%; p=0.005).
Conclusions
The novel tapered-tip sheath system is a promising option for precisely and safely delivering biopsy forceps to target sites, thereby facilitating the diagnosis of biliary strictures.
2.Efficacy and Safety of a Novel Tapered-Tip Sheath System for Biliary-Lesion Tissue Sampling: A Randomized Controlled Trial
Hirokazu OKADA ; Norimitsu UZA ; Tomoaki MATSUMORI ; Hajime YAMAZAKI ; Muneji YASUDA ; Takeshi KUWADA ; Yoshihiro NISHIKAWA ; Takahisa MARUNO ; Masahiro SHIOKAWA ; Atsushi TAKAI ; Ken TAKAHASHI ; Akihisa FUKUDA ; Etsuro HATANO ; Sachiko MINAMIGUCHI ; Hiroshi SENO
Gut and Liver 2025;19(1):136-144
Background/Aims:
Pathological evaluation is crucial for diagnosing biliary lesions and determining appropriate treatment strategies. However, tissue sampling via the transpapillary route can be difficult. In this study, we aimed to assess the efficacy and safety of a novel tapered-tip sheath system for tissue sampling from biliary strictures.
Methods:
This single-center, randomized, parallel-group clinical trial included patients aged 20 to 85 years admitted to Kyoto University Hospital for biliary strictures. The patients were randomly assigned (1:1) to a new or conventional method group. The primary outcome was technical success of biopsy at the target bile duct using the assigned method, as determined in accordance with the intention-to-treat principle. Adverse events were assessed in all eligible patients.
Results:
Fifty-six patients were assessed for eligibility between September 2020 and March 2023; 50 patients were enrolled. The patients were randomly divided into the new (n=25) method group and the conventional (n=25) method group. Technical success was achieved in 96.0% (24/25) and 48.0% (12/25) of patients in the new and conventional method groups, respectively (risk ratio, 2.00; 95% confidence interval [CI], 1.32 to 3.03; risk difference, 48.0%; 95% CI, 27.0% to 69.0%; p<0.001). Adverse events occurred in 4.0% (1/25) and 36.0% (9/25) of patients in the new and conventional method groups, respectively (risk ratio, 0.11; 95% CI, 0.02 to 0.81; risk difference, –32.0%; 95% CI, –52.3% to –11.7%; p=0.005).
Conclusions
The novel tapered-tip sheath system is a promising option for precisely and safely delivering biopsy forceps to target sites, thereby facilitating the diagnosis of biliary strictures.
3.Efficacy and Safety of a Novel Tapered-Tip Sheath System for Biliary-Lesion Tissue Sampling: A Randomized Controlled Trial
Hirokazu OKADA ; Norimitsu UZA ; Tomoaki MATSUMORI ; Hajime YAMAZAKI ; Muneji YASUDA ; Takeshi KUWADA ; Yoshihiro NISHIKAWA ; Takahisa MARUNO ; Masahiro SHIOKAWA ; Atsushi TAKAI ; Ken TAKAHASHI ; Akihisa FUKUDA ; Etsuro HATANO ; Sachiko MINAMIGUCHI ; Hiroshi SENO
Gut and Liver 2025;19(1):136-144
Background/Aims:
Pathological evaluation is crucial for diagnosing biliary lesions and determining appropriate treatment strategies. However, tissue sampling via the transpapillary route can be difficult. In this study, we aimed to assess the efficacy and safety of a novel tapered-tip sheath system for tissue sampling from biliary strictures.
Methods:
This single-center, randomized, parallel-group clinical trial included patients aged 20 to 85 years admitted to Kyoto University Hospital for biliary strictures. The patients were randomly assigned (1:1) to a new or conventional method group. The primary outcome was technical success of biopsy at the target bile duct using the assigned method, as determined in accordance with the intention-to-treat principle. Adverse events were assessed in all eligible patients.
Results:
Fifty-six patients were assessed for eligibility between September 2020 and March 2023; 50 patients were enrolled. The patients were randomly divided into the new (n=25) method group and the conventional (n=25) method group. Technical success was achieved in 96.0% (24/25) and 48.0% (12/25) of patients in the new and conventional method groups, respectively (risk ratio, 2.00; 95% confidence interval [CI], 1.32 to 3.03; risk difference, 48.0%; 95% CI, 27.0% to 69.0%; p<0.001). Adverse events occurred in 4.0% (1/25) and 36.0% (9/25) of patients in the new and conventional method groups, respectively (risk ratio, 0.11; 95% CI, 0.02 to 0.81; risk difference, –32.0%; 95% CI, –52.3% to –11.7%; p=0.005).
Conclusions
The novel tapered-tip sheath system is a promising option for precisely and safely delivering biopsy forceps to target sites, thereby facilitating the diagnosis of biliary strictures.
4.Efficacy and Safety of a Novel Tapered-Tip Sheath System for Biliary-Lesion Tissue Sampling: A Randomized Controlled Trial
Hirokazu OKADA ; Norimitsu UZA ; Tomoaki MATSUMORI ; Hajime YAMAZAKI ; Muneji YASUDA ; Takeshi KUWADA ; Yoshihiro NISHIKAWA ; Takahisa MARUNO ; Masahiro SHIOKAWA ; Atsushi TAKAI ; Ken TAKAHASHI ; Akihisa FUKUDA ; Etsuro HATANO ; Sachiko MINAMIGUCHI ; Hiroshi SENO
Gut and Liver 2025;19(1):136-144
Background/Aims:
Pathological evaluation is crucial for diagnosing biliary lesions and determining appropriate treatment strategies. However, tissue sampling via the transpapillary route can be difficult. In this study, we aimed to assess the efficacy and safety of a novel tapered-tip sheath system for tissue sampling from biliary strictures.
Methods:
This single-center, randomized, parallel-group clinical trial included patients aged 20 to 85 years admitted to Kyoto University Hospital for biliary strictures. The patients were randomly assigned (1:1) to a new or conventional method group. The primary outcome was technical success of biopsy at the target bile duct using the assigned method, as determined in accordance with the intention-to-treat principle. Adverse events were assessed in all eligible patients.
Results:
Fifty-six patients were assessed for eligibility between September 2020 and March 2023; 50 patients were enrolled. The patients were randomly divided into the new (n=25) method group and the conventional (n=25) method group. Technical success was achieved in 96.0% (24/25) and 48.0% (12/25) of patients in the new and conventional method groups, respectively (risk ratio, 2.00; 95% confidence interval [CI], 1.32 to 3.03; risk difference, 48.0%; 95% CI, 27.0% to 69.0%; p<0.001). Adverse events occurred in 4.0% (1/25) and 36.0% (9/25) of patients in the new and conventional method groups, respectively (risk ratio, 0.11; 95% CI, 0.02 to 0.81; risk difference, –32.0%; 95% CI, –52.3% to –11.7%; p=0.005).
Conclusions
The novel tapered-tip sheath system is a promising option for precisely and safely delivering biopsy forceps to target sites, thereby facilitating the diagnosis of biliary strictures.
5.Dynamic Cervical Spinal Canal Stenosis: Identifying Imaging Risk Factors in Extended Positions
Shogo MATSUMOTO ; Ryoma AOYAMA ; Junichi YAMANE ; Ken NINOMIYA ; Yuichiro TAKAHASHI ; Kazuya KITAMURA ; Satoshi NORI ; Satoshi SUZUKI ; Ukei ANAZAWA ; Tateru SHIRAISHI
Asian Spine Journal 2024;18(2):227-235
Methods:
This study analyzed 143 patients who underwent decompression surgery between 2012 and 2014, who had symptomatic cervical disorders and MRI evidence of spinal cord or nerve compression but had no history of cervical spine surgery. Patient demographics, disease type, Japanese Orthopedic Association score, and follow-up periods were recorded. Spinal surgeons conducted radiological evaluations to determine stenosis levels using computed tomography myelography or MRI in neutral and extended positions. Measurements such as dural tube and spinal cord diameters, cervical alignment, range of motion, and various angles and distances were also analyzed. The residual space available for the spinal cord (SAC) was also calculated.
Results:
During extension, new stenosis frequently appeared caudal to the stenosis site in a neutral position, particularly at C5/C6 and C6/C7. A low SAC was identified as a significant risk factor for the development of new stenosis in both the upper and lower adjacent disc levels. Each 1-mm decrease in SAC resulted in an 8.9- and 2.7-fold increased risk of new stenosis development in the upper and lower adjacent disc levels, respectively. A practical SAC cutoff of 1.0 mm was established as the threshold for new stenosis development.
Conclusions
The study identified SAC narrowing as the primary risk factor for new stenosis, with a clinically relevant cutoff of 1 mm. This study highlights the importance of local factors in stenosis development, advocating for further research to improve outcomes in patient with cervical spine disorders.
6.Disc Height Narrowing Could Not Stabilize the Mobility at the Level of Cervical Spondylolisthesis: A Retrospective Study of 83 Patients with Cervical Single-Level Spondylolisthesis
Ryoma AOYAMA ; Junichi YAMANE ; Ken NINOMIYA ; Yuichiro TAKAHASHI ; Kazuya KITAMURA ; Satoshi NORI ; Satoshi SUZUKI ; Tateru SHIRAISHI
Asian Spine Journal 2023;17(1):138-148
Methods:
The images of 83 patients with cervical single-level spondylolisthesis were studied. We looked at 52 slipped levels for anterior slippage and 31 for posterior slippage. The imaging parameters included slippage in the neutral, flexed, and extended positions, axial facet joint orientation, sagittal facet slope, global cervical alignment, C2–C7 angle, C2–C7 sagittal vertical axis, range of motion (ROM), and slipped disc angle ROM.
Results:
With the narrowing of the intervertebral disc height, slippage in the flexed position of both anterior and posterior spondylolisthesis increased. However, in both anterior and posterior spondylolisthesis, disc height narrowing did not show stability. The narrowing of the intervertebral disc height was found to be a risk factor for a translation of slippage of 1.8 mm or more in flexionextension motion in anterior spondylolisthesis in multivariate regression analysis.
Conclusions
Narrowing the intervertebral disc height did not stabilize the translation of slippage in flexion-extension motion in cervical spondylolisthesis. Instead, narrowing of the disc height was associated with a translation of slippage of 1.8 mm or more in flexion-extension motion in cases of anterior slippage. Therefore, we discovered that degenerative cascade stabilization for cervical spondylolisthesis was difficult to achieve.
7.Cervical Spinous Process and Its Attached Muscles Maintain Lower Disk Lordosis: A Retrospective Study of 155 Patients Who Underwent Muscle-Preserving Double Laminectomies
Ryoma AOYAMA ; Junichi YAMANE ; Ken NINOMIYA ; Yuichiro TAKAHASHI ; Kazuya KITAMURA ; Satoshi NORI ; Satoshi SUZUKI ; Tateru SHIRAISHI
Asian Spine Journal 2022;16(5):666-676
Methods:
In total, 155 consecutive patients who underwent muscle-preserving consecutive double laminectomies for cervical spondylotic myelopathy from 2005 to 2013 were included in this study. The imaging parameters included the C2–C7 angle, range of motion, C2–C7 sagittal vertical axis (SVA), C7 slope, C2–C5 angle, C5-C7 angle, local disk angle caudal to the decompression level, and the disk height between C2/C3 and C7/Th1.
Results:
The caudal disk angle of the decompression level decreased after consecutive double laminectomies, thus suggesting that the extension unit maintained the local lordosis at the lower disk of the decompression level. Postoperatively, in the C3–4 decompression cases, the C2–C7 angle decreased by 7.3°, and the C2–C7 SVA increased by 8.6 mm, thus indicating the appearance of an alignment disorder. Multivariate logistic regression analysis showed that cephalad laminectomy was a risk factor for C2–C7 angle decreases >10°. However, the postoperative recovery rate of Japanese Orthopedic Association scores after consecutive double laminectomies was reasonable, and the overall cervical alignment was well maintained in all decompression levels except C3–C4.
Conclusions
The cervical extension unit maintained lordosis at the disk caudal to it. The extension unit was found to contribute more to the maintenance of lordosis of the entire cervical spine at the cephalad side.
8.Endoscopic Findings and Treatment of Gastric Neoplasms in Familial Adenomatous Polyposis
Chihiro SATO ; Kazuya TAKAHASHI ; Hiroki SATO ; Takumi NARUSE ; Nao NAKAJIMA ; Masafumi TAKATSUNA ; Ken-ichi MIZUNO ; Satoru HASHIMOTO ; Manabu TAKEUCHI ; Junji YOKOYAMA ; Masaaki KOBAYASHI ; Shuji TERAI
Journal of Gastric Cancer 2022;22(4):381-394
Purpose:
Gastric neoplasia is a common manifestation of familial adenomatous polyposis (FAP). This study aimed to elucidate the clinical characteristics, endoscopic features including fundic gland polyposis (FGPsis), and treatment outcomes of gastric neoplasms (GNs) in patients with FAP.
Materials and Methods:
A total of 35 patients diagnosed with FAP, including nine patients from four pedigrees who underwent esophagogastroduodenoscopy (EGD), were investigated regarding patient characteristics, GN morphology, and treatment outcomes.
Results:
Twenty-one patients (60.0%) had 38 GNs; 33 (86.8%) and 5 (13.2%) were histologically diagnosed with adenocarcinoma and adenoma, respectively. There were no specific patient characteristics related to GNs.Nodule-type GNs were more prevalent in patients with FGP than without (52.2% vs. 0.0%, P=0.002) in the upper body of the stomach. Conversely, depressed-type GNs were fewer in patients with FGPsis than in those without (13.0% vs. 73.3%, P<0.001). Slightly elevated-type GNs were observed in both groups (34.8% vs. 20.0%, P=0.538). Even within pedigrees, the background gastric mucosa and types of GNs varied. In total, 24 GNs were treated with endoscopic submucosal dissection (ESD) and eight with endoscopic mucosal resection (EMR). EMR was selected for GNs with FGPsis because of the technical difficulty of ESD, resulting in a lower en bloc resection rate (62.5% vs. 100%, P=0.014).
Conclusions
Our study indicates the necessity of routine EGD surveillance in patients diagnosed with FAP. Notably, the morphology and location of GNs differed between patients with and without FGPsis. Endoscopic treatment and outcomes require more attention in cases of FGPsis.
9.Contraindication of Minimally Invasive Lateral Interbody Fusion for Percutaneous Reduction of Degenerative Spondylolisthesis: A New Radiographic Indicator of Bony Lateral Recess Stenosis Using I Line
Ken ISHII ; Norihiro ISOGAI ; Yuta SHIONO ; Kodai YOSHIDA ; Yoshiyuki TAKAHASHI ; Kenichiro TAKESHIMA ; Masanori NAKAYAMA ; Haruki FUNAO
Asian Spine Journal 2021;15(4):455-463
Retrospective cohort study. This study aimed to evaluate aggravated lateral recess stenosis and clarify the indirect decompression threshold by combined lateral interbody fusion and percutaneous pedicle screw fixation (LIF/PPS). No previous reports have described an effective radiographic indicator for determining the surgical indication for LIF/PPS. A retrospective review of 185 consecutive patients, who underwent 1- or 2-level lumbar fusion surgery for degenerative spondylolisthesis (DS). According to their symptomatic improvement, they were placed into either the “recovery” or “no-recovery” group. Preoperative computed tomography (CT) images were evaluated for the position of the superior articular processes at the slipping level, followed by a graded classification (grades 0–3) using the impingement line (I line), a new radiographic indicator. All 432 superior articular facets in 216 slipped levels were classified, and both groups’ characteristics were compared. There were 171 patients (92.4%) in the recovery group and 14 patients in the no-recovery group (7.6%). All patients in the no-recovery group were diagnosed with symptoms associated with deteriorated bony lateral recess stenosis. All superior articular processes of the lower vertebral body in affected levels reached and exceeded the I line (I line-; grade 2 and 3) on preoperative sagittal CT images. In the recovery group, most superior articular processes did not reach the I line (I line+; grade 0 and 1; In DS cases that are classified as grade 2 or greater, the risk of aggravated bony lateral recess stenosis due to corrective surgery is high; therefore, indirect decompression by LIF/PPS is, in principle, contraindicated.
10.Basic Verification of β-D Glucan in Leukocyte-Rich Plasma for the Diagnosis of Deep Mycosis
Ken SHIMOYAMA ; Shigenori KAN ; Gaku TAKAHASHI ; Gota MORINO ; Yasuhiko YAMADA ; Yoshihiro I INOUE ; Katsuya INADA ; Shigeatsu ENDO
Infection and Chemotherapy 2021;53(1):75-83
Background:
Currently, supplementary serological testing for β-D glucan (BDG) is often selected to diagnose deep mycosis in care covered by the health insurance in Japan. The Wako method used by our center has low sensitivity, and different studies have used different cut-off values due to factors that cause false positives and false negatives. One possible cause of false negatives is the use of platelet-rich plasma (PRP) as the sample material. Because phagocytic white blood cells (WBC) are precipitated by centrifugation and only plasma is measured, it seems unlikely that the actual amount of BDG is being measured when using PRP. Further, a frequent cause of false positives is contamination from blood products and gauze containing BDG. To resolve these issues, the blood cell separator, hydroxyethyl starch, is used to precipitate only the red blood cells to obtain leukocyte-rich plasma (LRP).We hypothesized that it might be possible to improve the diagnostic rate of deep mycosis by measuring the BDG content of plasma containing WBC and fungal components and by comparing the BDG content of PRP and LRP measured simultaneously.
Materials and Methods:
Healthy human blood, albumin-added blood, wrung-out gauze fluid-added blood, and fungal solution-added blood were prepared, and PRP and LRP were prepared using hydroxyethyl starch. The BDG content of each sample was measured using the Wako method and compared. In addition, PRP and LRP of fungal-added blood were Gramstained and examined under a microscope, and the number of WBCs and phagocytosed fungi was counted visually and compared.
Results:
Measuring the BDG content of LRP confirmed that there were no false positives with LRP, and in vitro experiments comparing albumin-added false-positive blood to fungal-added blood showed significant differences between PRP and LRP only in the fungal-added blood.
Conclusion
Calculating the BDG-ratio (LRP/PRP) by measuring both LRP and PRP may eliminate false positives and false negatives of true deep mycosis and improve the diagnostic rate.

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