Leg ulcers are areas of epidermal discontinuity in lower limbs with causes of venous, arterial, diabetic, pressure, traumatic, allergic, or inflammation. Chronic venous leg ulcers (VLUs) are defined as leg ulcers persisting for 4 weeks or more, a.k.a C6 in CEAP classification of chronic venous insufficiency (CVI) and account for up to 70% of all chronic leg ulcers exhibiting overall prevalence of up to 2% in the general population of western countries with significant morbidity and a negative socioeconomic impact. Wound care, debridement, bed rest with leg elevation, and compression are basic approaches for chronic VLUs. Meanwhile, numerous medical and surgical interventions were developed to promote wound healing and to prevent recurrence by focusing on pathophysiology of chronic VLUs. However, many strategies just have adjuvant effects or exert debatable benefits.

The lymphatic system been considered important for removal of excessive fluid from the interstitial space, absorption of fat from the intestine and the immune system, actively involved in regulation of immune cell trafficking and inflammation. Emerging lymphovenous bypass (LVB), a supermicrosurgical technique diverting lymphatic drainage into venous system in dealing with lymphedema, not only restores TH1 and TH2 imbalance, but decreases oxidative stress and increases antioxidant capacity in the serum of lymphedema patients. Clinically, LVB could be an alternative treatment option for patients with lymphorrhea.

Based on these facts, the investigators hypothesis that lymphatic hypertension and lymph impregnation contributes chronic venous leg ulcer formation and propose a novel strategy, using LVB to treat patients with refractory/recurrent chronic VLUs. The preliminary results revealed promising results and the investigators would go on clinical trials.

Inclusion Criteria:

• Age: 20~80 years
• Gender: All
• Poor wound healing after standard wound management for 4 weeks
• Deep vein thrombosis (DVT) has been ruled out by Duplex and Computer tomography or DVT has been treated
• Wound care with nursing specialty
• Recognize and agree to join this trial

Exclusion Criteria:

• Autoimmune status, such as systemic lupus erythematosus
• Heart, lung, kidney or liver failure patients
• Radiation related wound or cancer wound
• Those who cannot understand the trial
• Age less than 20 years or elder than 80 years
• Pregnancy
• Those who was Risky to receive general anesthesia or surgery
• Allergy to Patent Blue V or Gentian Violet