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vascular professional | issue 02 · 2022

One year after EVLA, a phone interview was performed Of course, it depends on the body size of patients, at
asking about any changes of their neurological symp- 40cm from the saphenofemoral junction, the posterior
toms. As a result, symptoms disappeared in 44%, relie- arch vein flows in GSV (> fig. 4).
ved in 48% and were not changed in 8% of the patients
> fig. 2. No patients reported any restrictions in their
quality of life.
40 30
50

60

fig. 4 > At the point of 40cm from the saphenofemoral
junction, saphenous nerve comes close to GSV. Below this

of saphenous nerve injury apparently arise.
fig. 2 > Change of neurological symptoms at 1 year © Junichi Utoh point, the nerve runs side by side with GSV and the risk © Junichi Utoh
after EVLA
Below this point, it is known that saphenous nerve comes
Discussion: close to GSV and runs side by side in a narrow segment
Nerve injury was observed in 3.1% of patients. The inci- of saphenous compartment. Therefore, GSV ablation for
dence of nerve injury was 4 times higher in cases of more than 40cm may cause some damage to the surroun-
ablation length of more than 40cm when compared to ding structures.
those under 40cm (5.2% vs 1.3%). A similar tendency was Indication of below-knee GSV ablation is still con-
observed in patients who underwent radiofrequency ab- troversial. In Japan, there is a dilemma. Half of vascular
lation of incompetent GSV during the same observation surgeons agree with it because of the benefit of a high
period in the Kumamoto Vascular Clinic > fig. 3. curability of EVLA. But the other half disagrees with it
because of a high risk of nerve injury. If saphenous nerve
injury becomes preventable, more patients would have
the opportunity to receive more curable EVLA in the
future.
The ablation power used in this study was 9W. Re-
viewing the clinical results, we considered that expo-
sure of below knee GSV to 9W was too large. There-
fore, some new improvements would be necessary to pre-
© Junichi Utoh vent nerve injury in below-knee GSV ablation.

fig. 3 >Incidence of nerve injury after EVLA and RFA A new protocol for below knee GSV ablation:

We have recently changed our protocol for GSV ablation.

Above Knee GSV Below Knee GSV

power 7 W 5 W
targeting LEED 50-70 J/cm 20-25 J/cm
ablation length 36.9 ± 5.4 cm 13.5 ± 5.6 cm
actual LEED 53.4 ± 9.6 J/cm 21.7 ± 3.8 J/cm

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