Future Of Laser Ablation: New Wavelength or Fiber Tip?

Thomas M. Proebstle

Dept of Dermatology University Medical Center Mainz

Germany

Disclosures last 12 monthsSapheon : study compensation, stocks

Covidien : study compensation, consultant fees

Cooltouch: research support

Approval Status of described devicesall approved in USA or Europe

Evolution of Laser Ablation: Wavelength

810, 940, 980 nm diode lasers

1064, 1320 nm Nd:YAG lasers

1470 nm diode laser

not yet established:

1310 nm diode and 2100 nm Holmium Laser

Hb H2O

Evolution of Fiber Tips

bare

ceramics

metal

radial

tulip

Meaning of Laser Wavelength

for

- in-vitro experiments

- anatomical success (vein occlusion)

clinical results and side effects

Hb H2O

In Vitro

Experiments

- carbonization of bare fiber tipscarbonization translates to higher tip temperature which may cause vein perforations

- counting perforations of vein tissue

- measuring perivenous temperature

Hb H2O

in-vitro

carbonization

of bare fiber tips

Hb H2O

T. Hennings et al, Phlebology 2014;29(3):1-8. epub 2013 May 6th

1320 nm Nd:YAG 980 nm Diode

in-vitro carbonization

of bare fiber tips

cw power 7W in blood

Hb H2O

1320 nm 20 Hz

100 µs pulses

-> peak power

3500 Watt

T. Hennings et al, Phlebology 2014;29(3):1-8. epub 2013 May 6th

Vein Wall Perforation940 diode vs 1320 nm YAG

Linear Endovenous Energy Density 940 nm: 15 W, 3 mm/s : 45 J/cm

30 W, 3 mm/s : 100 J/cm1320 nm: 8 W, 1 mm/s : 80 J/cm

5 W, 0.5 mm/s: 100J/cm

1320 nm: no perforation 940 nm: perforation,

carbonization

1320 nm 8 W, 1 mm/s control 5 W, 0.5 mm/s control

8 W, 1 mm/s control 5 W, 0.5 mm/s

20 mm 13 mm 8 mm

control 15 W 30 W

940 nm

1320 nm

Proebstle TM (2004) unpublished in-vitro experiments

in-vitro perivenous

temperature profile(may relate to nerve

damage and inflammation)

Hb H2O

Perivenous temperature profiles depend

on pullback speed and laser power – but

not on wavelength (940 vs 1470 nm)

Endovenous simulated laser experiments at 940 nm and 1470 nm suggest wavelength-independent temperature profiles.van den Bos RR et al, Eur J Vasc Endovasc Surg. 2012; 44:77-81.

Influence of Laser

Wavelength on

Anatomical Results

- any heat source (also RF or Steam) can can close a vein if the delivered energy dose is high enough (LEED – EFE)

- any laser wavelength and any fiber type can do the job

- differences in Clinical Results, QoL, side effect profile? Role of Fiber Tips?

Hb H2O

With bare fiber, 1320 nm caused less bruising,

less induration and less pain and analgesics than 940 nmProebstle et al, Dermatol Surg. 2005;31:1678-83

With bare fiber 980 nm caused less bruising

compared to 810 nmKabnick LS et al. J Vasc Surg. 2006; 43:88-93

Influence of Wavelength

on short term Clinical

Result and Side effects

Hb H2O

Influence of

Wavelength and

Fiber Tips on

Clinical Results and side effects

- Mid- and longterm clinical results are depending almost exclusively on anatomical results – successful reflux abolition is key !!

- Short term clinical results up to 6 weeks after intervention maybe influenced by side effects of Laser ablation procedure itself

Hb H2O

How can Fiber Tips affect side effects

bare

ceramics

metal

radial

tulip

cylindrical surface area A = 2 p r * h

surface of the CLF coil:

A = 0.23 cm * p * 7 cm = 5.06 cm²

estim. surface of the laseremitting part of the radial fiber tip:

A = 0.12 cm * p * 0.2 cm = 0.075 cm²

surface of the laser emittingsection of the bare fiber tip A = p r²

A = (0.03 cm)² * p = 0.0028 cm²

cylindrical surface area A = 2 p r * h

surface of the CLF coil:

A = 0.23 cm * p * 7 cm = 5.06 cm²

estim. surface of the laseremitting part of the radial fiber tip:

A = 0.12 cm * p * 0.2 cm = 0.075 cm²

surface of the laser emittingsection of the bare fiber tip A = p r²

A = (0.03 cm)² * p = 0.0028 cm²

factor 25

factor 65

Irradiance (10W) I = 2.8 kW/cm²

Irradiance (10W) I = 0.75 kW/cm²

Energy Flux aprox. 70 J/cm (in 20 s) „I“ = (70J /20s)/(5.06/7)cm² = o.oo5 kW/cm²

Massaki et al, Lasers Surg Med 45:123–129 (2013)

1320 nm Nd:YAG bare fiber and 810 nm diode with covered tip,

proved to be superior to 810 nm bare, 1470 nm bare, ….

Vein wall perforations at cw 7W in-vitro

different wave lengths

and fiber tips

Massaki et al, Lasers Surg Med 45:123–129 (2013)

Hb H2OVein wall perforations at cw 7W in-vitro

different wave lengths

and fiber tips

• No difference between diode laser wavelengths 810 – 1470 nm with bare fibers

• 1320 Nd:YAG (pulsed laser) seems to be the least perforating one with bare fibers

• with covered fiber tips even 810 nm reaches the maximum

Hb H2O

in-vitro results

summary

Clinical Effects

of

Fiber Tips ?

Group 1, 980 nm, 14W, bare fiber, 100% occlusion

Group 2, 1470 nm, 10W, covered tip, 100% occlusion

Duman et al. Diagn Interv Radiol (2013) 19( 4):326-9

Influence of Wavelength

and Fiber Tip on

short term Clinical

Result and Side effects

Hb H2O

no difference

Prospective Randomized Trial, N=60 patients, n=106 limbs

Group 1, 980 nm, bare fiber

Group 2, 1470 nm, radial fiber

Less pain, less analgesics, less complications,

better VCSS during the first month in group 2

Doganci S, Demirkilic U. Eur J Vasc Endovasc Surg. 2010; 40:254-9.

Hb H2OInfluence of Wavelength

and Fiber Tip on

short term Clinical

Result and Side effects

Influence of Wavelength

and Fiber Tip on

short term Clinical

Result and Side effects

Hb H2O

Prospective Cohort Study N=312 limbs, 1470 nm Laser

Group 1, 1470 nm bare fiber, n=168 limbs

Group 2, 1470 nm, radial fiber, n=144 limbs

Less pain, less analgesics in group 2 (p<0.04)

103 +/- 15 mg diclofenac vs 82 +/- 19 mg (single dose is 50 mg)

Less bruising in group 2 (p<0.0001)

Schwarz T, et al., J Vasc Surg. 2010;51:1474-8.

Summary (1)In-Vitro:

With bare fibers 1320 nm Nd:YAG Laser

may be superior with respect to vein perforation

Sophisticated fiber tips neutralize vein wall

damage for all wavelengths:

wavelength turns unimportant

Hb H2O

Summary (2)Clinically

Less traumatic fiber tips cause less side effects

like postinterventional pain, however,

differences are moderate

In the future the price of disposables may

become more important: In Europe open

connector fibers cost less than 100.- U$

Hb H2O

Hb H2OConclusion

All wavelengths and all type of fibers work

Sophisticated fiber tips may save a few doses of

Ibuprofen

Economical aspects of devices and disposables

will turn dominant