1. What is the “Best” Setting for Endovenous Laser Ablation? - A Pathological Analysis - R. Kansaku, N. Sakakibara, T. Shimabukuro, H. Endo, A. Amano, and T. Iwamura Department of Cardiovascular Surgery and Pathology, Jutendo University, Edogawa Hospital 1 7140-0233 Rev. A

2. Create a new standard technique of endovenous laser ablation (EVLA) for great saphenous veins in patients with varicose veins in their lower limbs. 2

3. What is the goal of this new technique? Regression (Cord-like Structure) Recanalization Perforation Occlusion Insufficiency EVLA Prevention OK ! 3

4. In the present study… pulsed wave laser …we reveal the mechanism of EVLA using pulsed wave laser. continuous wave laser 4

5. PowerFrequencyVelocityLEED Peak Power n WHzmm/secJ/cmWlegs Group A4.0201.04057110 Group B5.0301.05047610 Group C6.0401.06042810 Group D7.5401.07553510 PATIENTS with chronic venous disease who underwent EVLA 5

6. 1320 nm Nd:YAG Pulsed Wave Laser Automatic Pullback Device 2.5 F SaphFire Sterile Single Use Fiber 6

7. AzanHEEVG 7 EVLA using pulsed wave laser (1320 nm)

8. Alteration after EVLA without EVLA 8

9. Defect Perforation 9

10. Great Saphenous Veins in limbs with chronic venous disease (did not undergo EVLA / were not included in this study) AzanHEEVG 10

11. EVLA using continuous wave laser (980 nm) (not included in this presentation: in vitro study) AzanHEEVG 11

12. Group AGroup BGroup CGroup D 4.0W20Hz5.0W30Hz6.0W40Hz7.5W40Hz Peforation0 case (0%) 1 case (10%) Defect 1 case (10%)2 cases (20%)7 cases (70%)2 case (20%) 52.2 nm122.2 nm105.3 nm533.0 nm Alteration 5 cases (50%) 2 cases (20%)4 case (40%) 584.4 nm710.5 nm708.3 nm696.7 nm Thickness of Vein 345.2 nm357.5 nm404.2 nm417.3 nm 12

13. ? Recanalization: only 0.5% (in our hospital) There are few histological studies about EVLA available. EVLA using… Pulsed wave laser Chopped pulse wave laser Continuous wave laser 13 We highlight it this time

14. In most cases, the treated great saphenous vein was not identifiable 6 months after the EVLA using 1320 nm pulsed wave laser. Goldman MP. Dermatol Surg 2004;30:11:1380-5. Pre 3 months6 months 12 months 14

15. The actual energy delivered to the vein wall is different from the intended amount. In EVLA using contiunuous wave laser…. Beware: Narrow therapeutic window. der Kinderen, D. Dermatol Surg 2009 Theivacumar NS. Eur J Vasc Endovasc Surg 2009 perforaton recanalization 70 J/cm ≦ LEED ≦ 110 J/cm Too highToo low 15

16. 16 Tokyo Sky Tree