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2001 Fiscal Year Final Research Report Summary

DEVELOPMENT OF THE ENDOVASCULAR THROMBOLYSIS SYSTEM WITH SHOCK WAVE

Research Project

Project/Area Number 12307028
Research Category

Grant-in-Aid for Scientific Research (A)

Allocation TypeSingle-year Grants
Section一般
Research Field Cerebral neurosurgery
Research InstitutionTOHOKU UNIVERSITY

Principal Investigator

YOSHIMOTO Takashi  GRADUATE SCHOOL OF MEDICINE, TOHOKU UNIVERSITY, PROFESSOR, 大学院・医学系研究科, 教授 (50091765)

Co-Investigator(Kenkyū-buntansha) SAITO Tutomu  INSTITUTE OF FLUID SGIENCE, TOHOKU UNIVERSITY, ASSOCIATED PROFESSOR, 流体科学研究所, 助教授 (00302224)
TAKAYAMA Kazuyoshi  INSTITUTE OF FLUID SGIENCE, TOHOKU UNIVERSITY, PROFESSOR, 流体科学研究所, 教授 (40006193)
TAKAHASHI Akira  GRADUATE SCHOOL OF MEDICINE, TOHOKU UNIVERSITY, PROFESSOR, 大学院・医学系研究科, 教授 (40301048)
Project Period (FY) 2000 – 2001
KeywordsENDOVASCULAR INFRARED MONITOR / CEREBRAL EMBOLISM / ENDOVASCULAR THERAPY / SHOCK WAVE ENGINEERING / THROMBOLYSIS / LASER-INDUCED LIQUID JET / LASER MEDICINE / VASCULAR ENDOSCOPY
Research Abstract

Background and Objective
There are several problems inherent in the treatment of cerebral embolisms, such as the narrow therapeutic time window and the severe side effects of fibrinolytic drugs. It is thusnecessary to develop a new method of removing a cerebral thrombus more rapidly using smaller amounts of fibrinolytics. In the present, we investigated a liquid jet induced by holmium (Ho) : YAG laser irradiation in water.
Materials and Methods
In this study, a pulsed Ho : YAG laser whose wavelength, pulse duration, and energy were 2.1 μm, 350 μs, and 350 mJ/pulse, respectively. Behavior of Ho : YAG laser induced bubble in a capillary tube filled with pure water was observed at various stand-off distances (L ; distance between the optical fiber end and the capillary exit). After that, a liquid-jet generator was made by insertion of an optical fiber (diameter : 0.6 mm) into a catheter (6Fr) filled with pure water. The maximum penetration depth of a liquid jet generated with this device int … More o a gelatin artificial thrombus was measured at various stand-off distances (L ; destance between the optical fiber end and catheter exit). Moreover, the phenomenon and the pressure around the catheter were observed with a shadowgraph and PVDF needle hydrophon, respectively. Based on these results, a stand-off distance of 13 mm was chosen to investigate the enhancement of urokinase (UK) efficacy by only a single operation of the liquid-jet device in artificial thrombi made of human blood.
Results
A laser-induced bubble in a capillary tube rapidly grew forward and generated a liquid jet. Maximum penetration depth with the liquid-jet generating catheter increased in proportion to L and reached a maximum value (9 mm) when L was around 13 mm. A shock wave whose overpressure at a point several mm away from the catheter exit was over 12MPa was captured with shadowgraph Fabrinolysis rates (%) after incubation with a small amount of UK for 10 min and 30 min were predominantly raised by a single use of the laser-induced liquid jet (5.4 ± 2.4 vs. 22.6 ± 6.1 and 7.3 ± 3.8 vs. 38.3 ± 5.6, respectively (mean ± SD, p<0.001)).
Conclusions
Ho : YAG laser irradiation within a capillary tube filled with water caused liquid jet formation, which promoted the effect of fibrinolytics. Moreover, this jet was accompanied with shock waves, which might enable to facilitate endovascular balloon angioplasty by cracking subintimal calcified lesions. The liquid jet generation system is so simple that will be applied to an endovascular system for cerebral fibrinolysis in the near future. Less

  • Research Products

    (16 results)

All Other

All Publications (16 results)

  • [Publications] Saito R et al.: "Combined Neuroendovascular Stenting and Coils Embolization for Cervical Carotid Artery Dissection Causing Symptomatic Mass Effect"Surgical Neurology. 53. 318-322 (2000)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] S.H.R.Hosseini et al.: "Study on laser driven underwater shock waves for medical applications"平成11年度衝撃波シンポジウム講演論文集. 613-616 (2000)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Hirano T et al.: "Enhancement of fibrinolytics with a laser-induced liquid jet"Lasers in Surgery and Medicine. 29. 360-368 (2001)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Nakagawa A et al.: "characteristics of Holmium YAG laser-induced jet and its possibility as a novel method for dissection"Lasers in Surgery and Medicine. (in press). (2002)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Hirano T et al.: "A Novel Method of Drug Delivery for Fibrinolysis with Ho : YAG Laser-Induced Li1uid jet"Lasers in Medical Science. (in press). (2002)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Hirano T et al.: "Formation of a liquid jet by interaction between a laser-induced bubble and shock wave"Interventional Neuroradiology. (in press). (2002)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] 平野孝幸 他: "Ho : YAG レーザー誘発液体ジェットによる血栓溶解の促進"第79期日本機械学会流体工学部門講演会講演論文集. (CD-ROM版). (2001)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Komatsu M et al.: "Basic research on laser-induced shock/bubble interaction and water flow for medical application"proceedings of 1st International Symposium on Advanced Fluid Information. 567-572 (2001)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Saito R et al.: "Combined Neuroendovascular Stenting and Coils Embolization for Cervical Carotid Artery Dissection Causing Symptomatic Mass Effect"Surgical Neurology. Vol. 53. 318-322 (2000)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] S.H.R. Hosseini et al.: "Study on laser driven underwater shock waves for medical applications"Proceedings of Japanese Symposium on Shock Waves. 613-616 (2000)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Hirano T, Komatsu M, Saeki T, Uenohara H, Takahashi A, Takayama K, Yoshimoto T: "Enhancement of fibrinolytics with a laser-induced liquid jet"Lasers in Surgery and Medicine. Vol. 29 (4). 360-368 (2001)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Hirano T, Komatsu M, Saeki T, Uenohara H, Takahashi A, Takayama K, Yoshimoto T: "Laser-Induced Liquid Jet Accompanied With Shock Wave Generation ; A New Drug Delivery System For The Therapy of Cerebral Embolisms"Proceedings of 23 th. International Symposium on Shock Waves. (CD-ROM)Edition. (2001)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Komatsu M, Saeki T, Hirano T, Uenohara H, Takahashi A, Yoshimoto T, Takayama K: "Basic research on laser-induced shock/bubble interaction and water flow for medical application"Proceedings of 1st International Symposium on Advanced F Information. 2001. 567-572 (2001)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Hirano T, Komatsu M, Ezura M, Uenohara H, Takahashi A, Takayama K, Yoshimoto T: "Formation of a liquid jet by interaction between a laser-induced bubble and a shock wave"Interventional Neuroradiology. (in press). (2002)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Hirano T, Komatsu M, Uenohara H, Takahashi A, Takayama K, Yoshimoto T: "A Novel Method of Drug Delivery for Fibrinolysis with Ho : YAG Laser-Induced Liquid Jet"Lasers in Medical Science. (in press). (2002)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Nakagawa A, Hirano T, Komatsu M, Uenohara H, Ohyama H, Yoshida Y, Shirane R, Takayama K, Yoshimoto T: "Characteristics of Holmium YAG laser-induced jet and its possibility as a novel method for dissection"Lasers in Surgery and Medicine. (in press). (2002)

    • Description
      「研究成果報告書概要(欧文)」より

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Published: 2003-09-17  

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