Lower extremity varicose veins (LEVV) are common among elderly patients and can cause leg heaviness, pain, and swelling. In some older adults, venous congestion may contribute to knee or peri-knee pain, which is often misattributed to degenerative joint disease alone. Evidence on whether varicose vein treatment can relieve knee pain in very elderly patients (aged 80 years or older) is limited.

This prospective cohort study aims to evaluate the effectiveness and safety of endovenous ablation (EVA) for improving knee pain in elderly patients with symptomatic varicose veins. The study will include participants aged 80 years or older who present with both lower extremity varicose veins and knee joint pain. Eligible patients will undergo endovenous thermal ablation (radiofrequency or endovenous laser ablation) as the primary intervention.

Participants will be assessed at baseline, 1 month, 3 months, 6 months, and 12 months after treatment. The primary outcome is the change in knee pain intensity measured by the Visual Analog Scale (VAS) from baseline to 6 months. Secondary outcomes include changes in knee joint function (assessed by the Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC] or Knee Injury and Osteoarthritis Outcome Score [KOOS]), venous clinical severity score (VCSS), limb heaviness, quality of life (assessed by EQ-5D), and procedure-related complications.

Safety will be evaluated by recording peri-procedural adverse events, including deep vein thrombosis, skin burns, nerve injury, and postoperative infection. The study will also analyze whether preexisting osteoarthritis, venous reflux severity, or body mass index (BMI) affect the magnitude of pain improvement.

The hypothesis is that endovenous ablation improves knee pain in elderly patients by reducing venous congestion around the knee and improving venous return. This study will help clarify whether treating varicose veins can provide additional benefits for knee pain and mobility in patients aged 80 years and older.

Inclusion Criteria:

Adults aged ≥80 years. Clinical diagnosis of lower limb varicose veins with documented venous reflux on duplex ultrasound (CEAP C2-C4).

Presence of knee pain lasting ≥4 weeks prior to enrollment, confirmed by patient-reported VAS/NRS ≥3 at baseline.

Planned to undergo standard endovenous treatment (radiofrequency ablation, endovenous laser ablation, or equivalent).

Ability to provide informed consent and complete study questionnaires.

Exclusion Criteria:

Prior surgery or endovenous ablation for varicose veins in the same limb. History of inflammatory arthritis (e.g., rheumatoid arthritis, gout) or other systemic rheumatologic disease.

Recent acute knee injury (ligament, meniscus, fracture) within 6 months. Prior knee replacement or major knee surgery. Recent intra-articular injection or arthroscopy (<3 months). Known deep vein thrombosis or history of pulmonary embolism within the past 6 months.

Severe peripheral arterial disease (ABI <0.8). Pregnancy or breastfeeding. Inability to comply with follow-up schedule or complete questionnaires.

This study will enroll elderly patients aged 80 years or older who are diagnosed with primary lower extremity varicose veins and who also experience knee or peri-knee pain. Participants will be recruited from the outpatient vascular surgery clinics and inpatient wards of the participating hospital. All participants must be ambulatory and able to complete pain and function questionnaires. The study population represents older adults who are candidates for endovenous ablation under tumescent local anesthesia and who may benefit from venous reflux correction.