Preliminary experimental research for radiotherapy to prevent venous restenosis concerning blood access trouble of hemodialysis

2001 Fiscal Year Final Research Report Summary

• Project/Area Number: 12670865
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Radiation science
• Research Institution: Mie University
• Principal Investigator: NOMOTO Yoshihito Mie University, Hospital, assistant, 医学部・附属病院, 助手 (10252363)
• Co-Investigator(Kenkyū-buntansha): KATO Noriyuki Mie University, Hospital, lecturer, 医学部・附属病院, 講師 (40214390)
• Project Period (FY): 2000 – 2001
• Keywords: hiemodialysis / blood access / veous restenosis / neointimal hyperplasia / rabbit / percutaneous transluminal angioplasty / radiotherapy

Research Abstract

For patients undergoing long-term hemodialysis, stenosis of the blood access is a significant problem and needed for percutaneous transluminal angioplasty for several time in many cases. The endovascular brachytherapy has been considered effective treatment for restenosis of coronary arteries and peripheral arteries following percutaneous transluminal angioplasty and stent placement. For the arterial lesions, the biological process is considered neointimal hyperplasia caused by smooth muscle cell hyperplasia and proliferation, and migration to intima. Although the basic restenotic process is thought to be similar to venous lesion, we were going to confirm the process experimentally using animal without stent placement.
Under anesthesia, 5Fr balloon catheter was inserted femoral vein of rabbit weighing 3.5 Kg. Rt. jagular vein was expanded by balloon with 7 mm diameter. After 40 days, vessel stenosis was observed with venography. At the site of minimal diameter, the percentage stenosis was 30 %. The percentage stenosis was caluculated according to the formula %=(1-MLD/CD)X 100, where MLD is measured lumen diameter and CD is control diameter. Histological analysis was made to transverse sections of the jagular vein. Intimal hyperplasia were observed in the sections located 0〜10 mm center from injured site. Altered local hemodynamics may play major role in the process of intimal hyperplasia. With these results, in the experimental model, it is indicated that radiation length should set up with 10 mm margin at least from expanded site.