TY - JOUR
T1 - Heat conduction from the exceedingly hot fiber tip contributes to the endovenous laser ablation of varicose veins
AU - van den Bos, R.R.
AU - Kockaert, M.A.
AU - Martino Neumann, H.A.
AU - Bremmer, R.H.
AU - Nijsten, T.
AU - van Gemert, M.J.C.
PY - 2009
Y1 - 2009
N2 - Lower-extremity venous insufficiency is a common condition, associated with considerable health care costs. Endovenous laser ablation is increasingly used as therapy, but its mechanism of action is insufficiently understood. Here, direct absorption of the laser light, collapsing steam bubbles and direct fiber-wall contact have all been mentioned as contributing mechanisms. Because fiber tips have reported temperatures of 800-1,300A degrees C during endovenous laser ablation, we sought to assess whether heat conduction from the hot tip could cause irreversible thermal injury to the venous wall. We approximated the hot fiber tip as a sphere with diameter equal to the fiber diameter, having a steady state temperature of 800A degrees C or 1,000A degrees C. We computed venous wall temperatures due to heat conduction from this hot sphere, varying the pullback velocity of the fiber and the diameter of the vein. Venous wall temperatures corresponding to irreversible injury resulted for a 3 mm diameter vein and pullback velocities < 3 mm/s but not for 5 mm and a parts per thousand yen1 mm/s. The highest wall temperature corresponded to the position on the wall closest to the fiber tip, hence it moves longitudinally in parallel with the moving fiber tip. We concluded that heat conduction from the hot fiber tip is a contributing mechanism in endovenous laser ablation
AB - Lower-extremity venous insufficiency is a common condition, associated with considerable health care costs. Endovenous laser ablation is increasingly used as therapy, but its mechanism of action is insufficiently understood. Here, direct absorption of the laser light, collapsing steam bubbles and direct fiber-wall contact have all been mentioned as contributing mechanisms. Because fiber tips have reported temperatures of 800-1,300A degrees C during endovenous laser ablation, we sought to assess whether heat conduction from the hot tip could cause irreversible thermal injury to the venous wall. We approximated the hot fiber tip as a sphere with diameter equal to the fiber diameter, having a steady state temperature of 800A degrees C or 1,000A degrees C. We computed venous wall temperatures due to heat conduction from this hot sphere, varying the pullback velocity of the fiber and the diameter of the vein. Venous wall temperatures corresponding to irreversible injury resulted for a 3 mm diameter vein and pullback velocities < 3 mm/s but not for 5 mm and a parts per thousand yen1 mm/s. The highest wall temperature corresponded to the position on the wall closest to the fiber tip, hence it moves longitudinally in parallel with the moving fiber tip. We concluded that heat conduction from the hot fiber tip is a contributing mechanism in endovenous laser ablation
U2 - https://doi.org/10.1007/s10103-008-0639-y
DO - https://doi.org/10.1007/s10103-008-0639-y
M3 - Article
C2 - 19219485
SN - 0268-8921
VL - 24
SP - 247
EP - 251
JO - Lasers in Medical Science
JF - Lasers in Medical Science
IS - 2
ER -