ObjectiveTo compare the efficacy of varicose great saphenous vein (GSV) treatment alone versus combined treatment with iliac vein compression (IVC) intervention in improving lower extremity symptoms and prognosis among the patients with varicose GSV complicated by IVC. MethodsBased on inclusion and exclusion criteria, the patients with varicose GSV complicated by IVC treated at the Day Service Center of the First Affiliated Hospital of Chongqing Medical University from May 2022 to January 2025 were retrospectively enrolled. The patients were assigned into two groups according to the treatment strategies: the varicose GSV treatment alone group (control group) and the combined treatment group for varicose GSV and IVC (observation group). The primary endpoints included the closure rate of the GSV trunk, venous clinical severity score (VCSS), and venous insufficiency epidemiological and economic study quality of life/symptom (VEINES-QOL/Sym) questionnaire score at 6 and 12 months postoperatively. The significance level was set at α=0.05. ResultsA total of 264 patients with left lower extremity varicose GSV complicated by IVC were included. The observation group comprised 32 patients, while the remaining 232 patients underwent 1∶3 propensity score-matching, resulting in 96 matched patients in the control group. The baseline characteristics, including gender, age, and comorbidities, showed no statistically significant differences between the two groups (P>0.05). At 12 months postoperatively, the GSV trunk closure rate was 100% in both groups. Within-group comparisons revealed significant improvements in the VCSS and VEINES-QOL/Sym points at 6 and 12 months as compared with preoperative (on admission) values (P<0.05). Between-group comparisons showed that the observation group had greater improvement in the VEINES-QOL/Sym score at 6 months (P=0.028), but no significant difference in the VCSS (P=0.775); At 12 months, the observation group demonstrated significantly better the VCSS (P<0.001) and VEINES-QOL/Sym points (P<0.001) as compared with the control group. ConclusionsFor patients with left lower extremity GSV varicosities complicated by IVC, both treatment strategies significantly improve symptoms. Results of short-term follow-up (6 months) demonstrate early advantages in quality of life improvement with concurrent IVC intervention, while results of 12-month follow-up indicate superior efficacy in both symptom relief and quality of life enhancement. Therefore, concurrent IVC intervention may provide greater clinical benefits for mid- to long-term prognosis for patients with left lower extremity GSV varicosities complicated by IVC.