Takahashi, Ryohei



School of Medicine, Department of Urology (Shinanomachi)



Profile 【 Display / hide

  • 泌尿器分野の研究を行っております

Career 【 Display / hide

  • 2011.04

    さいたま市立病院, 初期臨床研修医

  • 2013.04

    慶應義塾大学医学部, 泌尿器科学教室, 助教

  • 2014.04

    国家公務員共済組合連合会 立川病院, 泌尿器科, 医員

  • 2015.04

    東京都立小児総合医療センター, 泌尿器科, 医員

  • 2016.04

    東京歯科大学市川総合病院, 泌尿器科, 助教

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Academic Background 【 Display / hide

  • 2005.04

    Keio University, 医学部, 医学科

    日本, University, Graduated

Licenses and Qualifications 【 Display / hide

  • 緩和ケア研修, 2012.07

  • 日本泌尿器科学会専門医, 2017.10


Research Areas 【 Display / hide

  • Urology

  • Immunology


Papers 【 Display / hide

  • Successful Treatment of End-stage Renal Disease in a Patient With Chronic Myeloid Leukemia by Kidney Transplantation and Tyrosine Kinase Inhibitors: A Case Report

    Shinoda K., Morita S., Tamaki S., Takahashi R., Kitaoka S., Asanuma H., Yoshida T., Okayama M., Kasahara H., Okamoto S., Oya M.

    Transplantation Proceedings (Transplantation Proceedings)   2020

    ISSN  00411345

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    © 2020 Elsevier Inc. Consensus regarding kidney transplantation feasibility in patients with chronic myeloid leukemia (CML) well controlled by tyrosine kinase inhibitors has not yet been achieved. Here, we report a patient with CML well controlled by tyrosine kinase inhibitors who developed end-stage renal disease during treatment and underwent kidney transplantation. CML activity has been carefully and successfully controlled for 4 years post-transplant. Very cautious dose adjustment and temporary cessation of nilotinib were required because kidney function fluctuated in reference to the doses of nilotinib.

  • Small intestinal perforation due to a huge gastrointestinal stromal tumor in a kidney transplant recipient: A case report and literature review

    Takahashi R., Shinoda K., Ishida T., Hamamoto Y., Morita S., Akita H., Kitaoka S., Tamaki S., Asanuma H., Yoshida T., Jinzaki M., Kameyama K., Oya M.

    BMC Nephrology (BMC Nephrology)  20 ( 1 )  2019.04

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    © 2019 The Author(s). Background: Gastrointestinal stromal tumors (GISTs) in transplant recipients are very rare and only a handful of cases have been reported to date. Here we present the first known case of a huge GIST in a kidney transplant recipient with perforation of small intestine. Case presentation: A 64-year-old male presented at our hospital with right colic pain; he had received an ABO incompatible kidney transplant 6 years earlier and was treated with cyclosporine, mycophenolate mofetil, and methylprednisolone. Radiological evaluation revealed a huge (11 cm in diameter) solitary tumor at the small intestine without distant metastasis. The small intestinal wall at the tumor location was perforated one week after diagnosis and the patient underwent emergency surgery. The pathological findings were compatible with GIST and the tumor consisted of spindle cells with positive staining for KIT, CD34, and DOG1 and negative or weak staining for desmin and S-100 protein. A mutation in exon 11 of the c-kit gene was also detected. Cyclosporine was withdrawn and imatinib mesylate (400 mg daily) was introduced. However, thereafter, we needed to decrease the dose at 300 mg daily due to severe hyponatremia. Reduced imatinib treatment was well tolerated and recurrence was not observed for 18 months after surgery. Conclusions: The occurrence of GISTs in transplant patients is rare, and huge GISTs should be resected immediately after diagnosis because gastrointestinal tract at the tumor site could be perforated. Imatinib treatment is feasible in transplant recipients under immunosuppression, although immunosuppressive drugs metabolized by CYP3A4 should be used at a reduced dosage or withdrawn.

  • Pre-donation BMI and preserved kidney volume can predict the cohort with unfavorable renal functional compensation at 1-year after kidney donation

    Shinoda K., Morita S., Akita H., Tamaki S., Takahashi R., Kono H., Asanuma H., Kikuchi E., Jinzaki M., Nakagawa K., Oya M.

    BMC Nephrology (BMC Nephrology)  20 ( 1 )  2019.02

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    © 2019 The Author(s). Background: The magnitude of renal function recovery after kidney donation differs in donors with a heterogeneous background. Preoperative assessment of candidates with potentially unfavorable renal functional compensation is critical when baseline kidney function is marginal. We explored the significance of preserved kidney volume (PKV) and known preoperative risk factors for the prediction of unfavorable renal function compensation. Methods: We enrolled 101 living donors for whom a 1-mm sliced enhanced computed tomography scan was performed preoperatively and clinical data could be collected up to 1 year after donation. The donors whose estimated glomerular filtration rate (eGFR) at 1 year after donation was 70% or higher of baseline eGFR were assigned to the "favorable renal compensation" group and the others to the "unfavorable renal compensation" group. Results: Age, sex, and preoperative serum uric acid level were not significant predictors for "unfavorable renal compensation." Multivariable logistic regression analysis revealed that body mass index (BMI) and body surface area (BSA)-adjusted PKV were independent preoperative risk factors for "unfavorable renal compensation" (adjusted odds ratio, 1.342 and 0.929, respectively). Hypertension and preoperative eGFR were not independent predictors when adjusted with BMI and BSA-adjusted PKV. Receiver operative characteristic analysis revealed that the predictive equation with the two independent predictors yielded a good accuracy to detect donor candidates with unfavorable renal functional compensation (area under the curve = 0.803), and the optimal cut-off values were identified as 23.4 kg/m 2 for BMI and 107.3 cm 3 /m 2 for BSA-adjusted PKV. Conclusions: BMI and BSA-adjusted PKV may be useful to select candidates with potentially unfavorable renal function compensation before kidney donation.

  • Preserved Kidney Volume, Body Mass Index, and Age Are Significant Preoperative Factors for Predicting Estimated Glomerular Filtration Rate in Living Kidney Donors at 1 Year After Donation

    Shinoda K., Morita S., Akita H., Washizuka F., Tamaki S., Takahashi R., Oguchi H., Sakurabayashi K., Mizutani T., Takahashi Y., Hyodo Y., Itabashi Y., Muramatsu M., Kawamura T., Asanuma H., Kikuchi E., Jinzaki M., Shiraga N., Nakagawa K., Oya M., Shishido S., Sakai K.

    Transplantation Proceedings (Transplantation Proceedings)  51 ( 5 ) 1306 - 1310 2019

    ISSN  00411345

     View Summary

    © 2019 Elsevier Inc. Background: Securing postdonation renal function in the lifetime of donors is a consequential subject for physicians, and precise prediction of postdonation renal function would be considerably beneficial when judging the feasibility of kidney donation. The aim of this study was to investigate the optimum model for predicting eGFR at 1 year after kidney donation. Methods: We enrolled 101 living-related kidney donors for the development cohort and 44 for the external validation cohort. All patients in each cohort underwent thin-sliced (1 mm) enhanced computed tomography (CT) scans. We excluded individuals with diabetes, glucose intolerance, or albuminuria from this study. We evaluated preoperative factors including age, sex, hypertension, body mass index (BMI), serum uric acid, baseline eGFR, and body surface area (BSA)-adjusted preserved kidney volume (PKV) by using 3-dimensional reconstruction of thin-sliced enhanced CT images. To detect independent predictors, we performed multivariable regression analysis. Results: The multivariable regression analysis revealed that age, BMI, predonation eGFR, and BSA-adjusted PKV were independent predictors of eGFR at 1 year after kidney donation (correlation coefficient: −0.15, −0.476, 0.521, 0.127, respectively). A strong correlation between predicted eGFR and observed eGFR was obtained in the development cohort (r = 0.839, P < .0001). The significance of this predictive model was also confirmed with the external validation cohort (r = 0.797, P < .0001). Conclusions: Age, BMI, predonation eGFR, and BSA-adjusted PKV may be useful for precisely predicting eGFR at 1 year after living kidney donation and be helpful to determine the feasibility of kidney donation from marginal donors.

Presentations 【 Display / hide

  • 経皮的リンパ管造影が治療に有効であった腎移植後リンパ嚢腫の一例

    腎移植血管外科学会, 2018, Oral Presentation(general)

  • 生体腎移植5年後に小腸GISTを発症し消化管穿孔を来した一例

    臨床腎移植学会, 2018, Oral Presentation(general)

  • 単孔式腹腔鏡下副腎摘出術における術選択基準としてのBody Mass Indexカットオフ値

    (札幌) , 2018, Poster (general), 内分泌外科学会

  • 保存的加療を行った特発性腎動脈解離の一例

    Takahashi Ryohei

    腎移植血管外科 (小田原) , 2017, Oral Presentation(general)

  • エベロリムス併用プロトコールにおける脂質代謝についての検討

    Takahashi Ryohei

    臨床腎移植学会 (神戸) , 2017, Poster (general)

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