1. Study Design: A single-blind, prospective, randomized controlled trial (RCT) conducted at Kafrelsheikh University Hospital to compare the efficacy and safety of 1940 nm vs. 1470 nm diode lasers for EVLA.
2. Participants: The trial will enroll 220 adult patients (110 per group) presenting with symptomatic varicose veins (CEAP C2-C6) and duplex-proven saphenous reflux with a vein diameter \\bm{\< 12\\text{ mm}}.
3. Randomization \& Blinding: Patients are randomized in a 1:1 ratio via computer-generated sequences in sealed envelopes; patients and outcome assessors are strictly blinded, while the operating surgeon is unblinded.
4. Anesthesia: Procedures are performed under ultrasound-guided Local Tumescent Anesthesia (0.1% lidocaine with sodium bicarbonate in saline) to provide analgesia, a thermal sink, and venous compression.
5. Surgical Technique: A 600-µm radial fiber is introduced through a 6F sheath and positioned 2 cm distal to the SFJ/SPJ, followed by ablation in the Trendelenburg position at a pullback speed of 1 mm/s.
6. Laser Metrics: Group I (1940 nm) will utilize lower power settings (4-6 W; target LEED 30-50 J/cm), while Group II (1470 nm) will follow standard practice guidelines (10-12 W; target LEED 60-80 J/cm).
7. Follow-up \& Outcomes: Longitudinal surveillance will occur at Day 1, Day 7, 1 month, and 6 months, with the primary outcome defined as anatomical success (complete vein occlusion via duplex ultrasound at 6 months).
8. Statistical Analysis: Secondary metrics-including pain (VAS), clinical improvement (VCSS), and complications (EHIT, paresthesia)-will be analyzed via IBM SPSS, establishing a significance threshold of \\bm{p \< 0.05}.