Endovenous Laser Ablation

Transcription

1 Endovenous Laser Ablation 132 nm Wavelength with Clear Tip Technology vs. 147 nm Wavelength

2 Similarities and Differences 132nm and 147nm Both wavelengths are mid-infrared Water is the primary chromophore for both 147 nm has a very high water absorption coefficient compared to 132 nm This results in an extremely shallow depth of penetration (~3um) for 147 nm

3 Endothermal Heat Induced Thrombosis (EHIT) Mozes, Extension of Saphenous thrombus into the femoral vein: A potential complication of new endovenous techniques. Jour Vasc Surg Jan 25 Kabnick, Thrombus Extension at the SFJ after Endovenous Thermal Ablation: Should We Worry? Veith Symposium Kabnick, Thrombus Extensions after Thermal Ablation. IVC 21

4 So why does this matter? High water absorption and shallow penetration heats blood in the immediate vicinity of the fiber tip and produces large amounts of thrombus that can extend into the Saphenofemoral Junction. Endothermal Heat Induced Thrombosis (EHIT) 147 nm Wavelength 132 nm Clear Tip Technology

5 Why is Thrombosis Undesirable? Soft Thrombus that sticks to the fiber can be heated further to become char This results in vein wall perforations and can cause unnecessary pain and bruising EHIT extensions can lead to Pulmonary Embolisms (PE) and Deep Vein Thrombosis (DVT)

6 FDA MAUDE Data Base Between 21 and 29 two companies reported 119 EHIT extensions post Radio Frequency (RF) or EndoVenous Laser Ablation (EVLA) 73 cases of Pulmonary Embolism or Deep Vein Thrombosis with Hospitalization 4 deaths

7 147 nm Mimics 81 nm Average Coagulum Mass (g) 81 nm is known to cause more pain and bruising than 132 nm 147 nm produces equivalent soft thrombus to 81nm CW 132 (5Hz, 3µsec) Wavelength of Laser (nm) 147 CW

8 In Vitro Experiments Demonstrated vein wall perforations with 147 nm Methods Human vein suspended within cylinder of physiologic saline (prior to inserton of laser fber and subsequent laser treatment) Vein has been flled with porcine blood & laser fber has been inserted. Fiber is connected to automatc pull-back device. The light shows where the laser tp is within vein.

9 In Vitro Experiments Fibers appeared to stick to vein wall Coagulum formation on the tip Results (Macroscopic)

10 Histology Results 147 nm Perforations

11 CoolTouch with Clear Tip Technology

12 CoolTouch Clear Tip No Perforations Control 132 nm

13 Table of Results - Histology Total # crosssections evaluated Thermal damage* Perforation or full thickness necrosis of a portion of the vein wall** (# sectons where fnding is observed/ total # cross-sectons evaluated) 132nm pulsed PT, FT, AD 2/13 (15%) (%) 147nm diode 6 14 PT, FT, AD 4/6 (67%) (%) 11 8 PT, FT, AD (the later focally near perforatons) 5/11 (45%) (%) 81nm diode non-protected tip *Thermal damage (amorphous amphophilic material; coagulation necrosis) - affecting the partial thickness of media with intervening muscle cell nuclei still visible ("PT"), affecting the full thickness of media with intervening muscle cell nuclei still visible ("FT"), affecting the advential dermis ("AD") - (# sections where finding is observed/ total # cross-sections evaluated) **Perforation (channel or absence of tissue in a portion of the vein wall) or full thickness necrosis of a portion of the vein wall (muscle cell nuclei are not visible and are replaced by coagulation necrosis and amorphous basophilic material) (# sections where finding is observed/ total # cross-sections evaluated)

14 Sakakibara N, Edogawa Japan Power Freq LEED W Hz J/cm Ulcer Perforation Specimens (27%) 11 (73%) (67%) 1 (33%) 3 3) (5%) 2 (5%) 4 4) ) ) ) Device 1) 2) 6) 98 CW 147 CW 132 PW Numbers

15 Downsides of 147 nm Special radial fibers must be used to deliver energy to vein wall when using 147 nm Single use and expensive Larger access needed - 1mm Increased pain and bruising due to vein wall perforations Possible increased risk of DVTs Difficult to successfully close larger veins Lower closure rates than 132 nm

16 The 132 nm Reality A success rate of 99%+ with over 5 year follow up Minimal pain and bruising, lowest complication rate Closes large veins >2mm Best at closing side branches Lowest cost per fiber use of any licensed EV ablation system Exclusive automatic pull back device Why even consider anything else?

17 CoolTouch CTEV Exclusive JouleTracker with dosimetry readout. Speeds of up to 2mm/sec Exclusive hand controller Exclusive dual footswitch Exclusive Clear Tip technology Exclusive SaphFire rounded tip fiber for tortuous veins Reusable fibers US patents 7,921,854 and 7,524,316