Lower extremity lymphedema is a chronic and progressive condition associated with significant functional impairment and reduced quality of life. The current gold-standard treatment is Complex Decongestive Therapy (CDT); however, a substantial proportion of patients continue to experience persistent symptoms during the maintenance phase. This prospective, randomized, double-blind, placebo-controlled clinical trial aims to evaluate the effectiveness of Extracorporeal Shock Wave Therapy (ESWT) as an adjunct to standard CDT maintenance therapy in patients with lower extremity lymphedema. Participants will be randomly allocated to either an active ESWT group or a sham ESWT group, with both groups continuing standard CDT maintenance throughout the study. ESWT will be administered twice weekly for five sessions. Changes in limb volume, skin thickness and subcutaneous tissue thickness assessed by ultrasonography, pain, functional status, and quality of life will be evaluated at baseline, after treatment, and at one-month follow-up.

Lower extremity lymphedema results from impairment of the lymphatic system and is characterized by progressive tissue fibrosis, chronic limb swelling, recurrent infections, and reduced quality of life. Complex Decongestive Therapy (CDT), recommended by the International Society of Lymphology, remains the gold-standard treatment. Despite adherence to CDT, many patients continue to experience persistent symptoms and functional decline, underscoring the need for effective adjunctive interventions.

Extracorporeal Shock Wave Therapy (ESWT) is a non-invasive modality that has shown potential benefits in reducing fibrosis and improving lymphatic function. While its efficacy has been reported in upper extremity lymphedema, evidence in lower extremity lymphedema remains limited.

This single-center, prospective, randomized, double-blind, placebo-controlled trial will be conducted at the Department of Physical Medicine and Rehabilitation, Gazi University Faculty of Medicine. Patients currently in CDT Phase 2 (maintenance phase) will be randomly assigned in a 1:1 ratio to receive either active ESWT or sham ESWT, using stratified randomization by lymphedema stage. All participants will continue standard maintenance therapy - compression garments, skin care, and exercise - throughout the study. ESWT will be applied to fibrotic tissue regions and periinguinal and peripopliteal lymph node areas using the EMS Swiss DolorClast® device, with 3,000 impulses per session at 20 Hz and 2 bar. The primary outcome is change in lower extremity circumferential measurements and limb volume. Secondary outcomes include skin and subcutaneous tissue thickness assessed by ultrasonography, pain intensity measured by the Visual Analogue Scale (VAS), lymphedema-specific quality of life evaluated by the LYMQOL-Leg, and functional status assessed by the Lower Extremity Functional Scale (LEFS). All outcomes will be assessed at baseline, immediately after treatment, and at one-month follow-up.

Inclusion Criteria:

• Adults aged 18 to 80 years
• Clinical diagnosis of lower extremity lymphedema established at least 6 months prior to enrollment
• Completion of at least one cycle of CDT Phase 1 (intensive decongestive phase) within the preceding six months
• Currently in CDT Phase 2 (maintenance phase) with active use of compression garments
• Ability and willingness to provide written informed consent

Exclusion Criteria:

• Active chemotherapy or radiotherapy
• Active infection
• Lower extremity vascular diseases including deep vein thrombosis or arterial insufficiency
• Presence of a cardiac pacemaker
• Pregnancy
• Bleeding disorders

Participants will be blinded to group allocation as sham ESWT is applied using identical positioning and device application as active ESWT, with only non-energized impulses delivered. Outcome assessments will be performed by an assessor who is blinded to group allocation.