Third generation of laser (>1900) for endovenous thermoablation (EVLA) of varicose veins: A systematic review and meta-analysis.

OBJECTIVES: Third generation lasers with longer wavelengths (>1900 nm) have been introduced, in recent years, for the treatment of varicose veins. The possible advantage of the new generation lasers is that they allow complete damage to the vein wall using a lower Power in Watts (W: J/sec) and a lower linear energy density (LEED: J/cm). The aim of this work is to evaluate the results present in the literature regarding efficacy and safeness of the new generation lasers for the treatment of varicose veins.

METHODS: Published articles were searched on PubMed database and on Cochrane Library, entering the keywords "1940 nm or 1920 nm laser AND varicose veins laser thermoablation (EVLA)." The primary endpoint of the study was to value rate of occlusion and adverse events at the short term follow-up. The search yielded a total of 14 studies. In the end, only six studies were judge eligibility.

RESULTS: The studies were heterogenous in their documentation, EVLA, duplex ultrasound protocol and result reporting. A total of 540 limbs of 377 patients were treated with endovenous laser ablation (EVLA) with laser 1920-1940 nm. The treated veins had a mean diameter of 0.74 ± 0.17 cm and a mean length of 27.87 ± 20.63 cm. The pooled estimates of immediate occlusion rate was of 99.8% (95% CI: 97.9% to 100.0) with high heterogeneity (I2 = 60%; 95% PI: 89.7% to 100%), while at short-term follow-up was of 98.2% (95% CI: 94.0% to 100.0%) with higher heterogeneity (I2 :79%; 95% PI: 77.1% to 100.0%). EHIT occurred in 7 cases (pooled estimate: 0.7%). The other adverse events rate reported were 1% of hyperpigmentation, 2.8% of neurological complications, 0.6% thrombophlebitis and 1.9% of bruising/hematoma. The pooled mean estimates of LEED was equal to 38.2 J/cm (95% CI: 26.3 to 50.1 J/cm) although with a very large heterogeneity (I2 = 100%).

CONCLUSIONS: The overall success rate of EVLA was high. The analysis of these studies suggests that using lower parameters (Power and linear administered energy) may have no effect on the treatment success rate. Short-term results demonstrate comparable occlusion rates respect the second-generation lasers. Instead, data suggest a low complication rates. Short-term results demonstrate comparable complications rates respect the second-generation lasers (1300-1470 nm). Randomized studies with longer follow-up are required to evaluate the EVLA 1900 nm procedure further.