KEIO RESEARCHERS INFORMATION SYSTEM

Licenses and Qualifications 【 Display / hide 】

Licenses and Qualifications 【 Display / hide 】

• 日本外科学会専門医, 2015.01

• USMLE Step 3, 2018.09

• 心臓血管外科学会専門医, 2020.01

• 日本循環器学会　循環器専門医, 2026.04

Papers 【 Display / hide 】

Papers 【 Display / hide 】

• Visceral segment interrupted constraining suture in physician-modified endografts for dissecting thoracoabdominal aortic aneurysms

  Hashizume K., Mori M., Yamazaki M., Yagami T., Haida H., Shimizu H.

  Journal of Vascular Surgery Cases Innovations and Techniques 12 ( 3 )  2026.06

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  Severe true lumen narrowing in chronic dissecting thoracoabdominal aortic aneurysms (dTAAAs) can compromise accurate fenestration alignment and hinder reliable bridging of the renovisceral branches. We evaluated the safety and feasibility of fenestrated endovascular aortic repair using a physician-modified endograft incorporating a visceral segment interrupted constraining suture. This permanent diameter-constraining modification is intended to stabilize the endograft within a narrowed true lumen and improve target vessel access. Sixteen patients with chronic dTAAA underwent elective repair using a low-profile Zenith Alpha Thoracic device. All 60 renovisceral branches were successfully bridged, resulting in 100% intraoperative technical success, defined as completion of the planned procedure with aneurysm sac sealing, with no 30-day mortality. Three patients required early reintervention for endoleak (1 type IC; 2 type IIIC). Follow-up imaging through 12 months demonstrated durable aneurysm exclusion and sustained branch patency. In this early experience, a visceral segment interrupted constraining suture provided reproducible diameter control and facilitated target vessel access in complex dTAAA treated by physician-modified endograft-based fenestrated endovascular aortic repair.

  • Access to Document (DOI)

• Right Atrial Thrombus After Cardiac Surgery With Tissue Expander in a Child With Right Pulmonary Agenesis

  Haida H., Yoshimura Y., Shimotakahara A.

  Annals of Thoracic Surgery Short Reports 4 ( 2 ) 674 - 677 2026.06

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  We report the case of a child with right pulmonary agenesis, congenital tracheal stenosis, and atrial septal defect (ASD). At age 2 years, an intrathoracic tissue expander was placed to reduce tracheal compression from mediastinal shift and to enable subsequent atrial septal defect closure. At age 5 years, a right atrial mass was incidentally detected along with right atrial compression caused by the expander. Emergency mass resection was performed, and the mass was diagnosed as a thrombus. The tissue expander was subsequently deflated and removed to prevent further compression. The patient had no recurrence of thrombus or respiratory symptoms during 8-year follow-up.

  • Access to Document (DOI)

• Standardization for Minimally Invasive Combined Aortic and Mitral Valve Surgery via a Right Minithoracotomy

  Yamazaki M., Takahashi T., Matsumoto Y., Haida H., Kimura N., Hashizume K., Ito T., Shimizu H.

  Annals of Thoracic Surgery Short Reports 4 ( 1 ) 123 - 126 2026.03

  　View Summary

  Surgeons have been reluctant to adopt minimally invasive combined aortic and mitral valve surgery through a minithoracotomy because of its complexity and prolonged cardiopulmonary bypass and aortic cross-clamping times. Our technique was designed to provide a close and frontal surgical visual field without the need for long-shafted specialized surgical instruments, thereby allowing a standardized and well-visualized surgical visual field in many cases. Here we describe the implementation of our minimally invasive combined aortic and mitral valve surgical procedure through a right minithoracotomy facilitated by the superior septal approach for mitral valve access.

  • Access to Document (DOI)

• Aorticopulmonary paraganglioma resected via a transaortic approach: A case report

  Sugino K., Suzuki S., Suzuki T., Okubo Y., Haida H., Masai K., Kaseda K., Hashizume K., Shimizu H., Asakura K.

  Jtcvs Techniques  2026

  • Access to Document (DOI)

• Branched stented anastomosis frozen elephant trunk repair reduces operative time and transfusion requirements in acute type A aortic dissection

  Hashizume K., Mori M., Matsuoka T., Koizumi K., Yamazaki M., Kimura N., Iida Y., Matsumoto Y., Haida H., Kasai M., Kaneyama H., Harada D., Shimizu H., Oki N., Aoyagi Y., Shimizu H.

  Jtcvs Open  2026

  　View Summary

  Background In acute type A aortic dissection (AADA) patients, total arch replacement (TAR) using the frozen elephant trunk (FET) technique has been adopted in emergencies to promote distal false lumen (FL) thrombosis. However, TAR is technically demanding and is associated with prolonged operative time and increased intraoperative blood transfusion. We previously reported the branched stented anastomosis frozen elephant trunk repair (B-SAFER) technique. Comparative data versus conventional TAR (cTAR) adjusted for disease severity remain limited. Here we compared the early surgical outcomes of TAR using B-SAFER versus cTAR in AADA. Methods This retrospective, multicenter, nonrandomized study included patients with AADA and a patent FL who underwent emergency TAR using B-SAFER (n = 63) and cTAR (n = 75). Propensity score matching based on EuroSCORE and JapanSCORE identified 48 matched pairs. After matching, 16 patients (33%) in the comparator group underwent conventional TAR without an FET device because of institutional practice patterns or device-related constraints. Results The 30-day mortality was 7.3% overall (7/96), with no significant difference between the groups (6.2% for B-SAFER vs 8.3% for cTAR; P > .999). Spinal cord ischemia occurred in 0% versus 4.2% ( P = .153). All operative time metrics were significantly shorter with B-SAFER (all P ≤ .024). Transfusion requirements for red blood cells, fresh frozen plasma, and platelets were all significantly lower (all P < .001). Conclusions In propensity score–matched patients with AADA, TAR using B-SAFER was safe and reproducible, with reduced operative times and transfusion requirements compared to cTAR.

  • Access to Document (DOI)

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Courses Taught 【 Display / hide 】

Courses Taught 【 Display / hide 】

• Introduction to Medicine Seminar

  2026, Undergraduate (liberal arts)

• CLINICAL CLERKSHIP IN CARDIOVASCULAR SURGERY

  2026

• CLINICAL CLERKSHIP IN CARDIOVASCULAR SURGERY

  2025, Full academic year, Undergraduate (specialized)