Introduction: Lymphedema is the accumulation of high protein interstitial fluid caused by obstruction of lymphatic flow. The lymph nodes and the lymphatic channels of the patients who have secondary lymphedema are damaged by radiation therapy or extracted by lymph node dissection. The morbidity of lymphedema can be devastating. The mainstay of treatment of lymphedema is conservative, but is often suboptimal. This includes compressive garments, message and physiotherapy, elevation, diet restriction, and sometimes pharmacotherapy. Although not definitive, procedures that attempt to enhance lymphatic drainage have much improved outcomes. These include lympho-lymphatic shunts, lympho-venous-anastomosis, and lympho-venous- lymphatic conduits. However, these procedures are extremely tedious and necessitate specialized microsurgeon. We hypothesize that auto-transplantation of a groin flap that includes lymphnodes to axilla for treatment of upper extremity lymphedema may allow regeneration of lymphatic vessels and enhance lymphatic flow. We confirmed the hypothesis by this experiment.

Methods: We obtained sixty rats to this study. The left forelimbs were circumferentially and volumetrically measured in comparison to the contralateral limb. All rats underwent the first operation, which was to create lymphedema. The skin and subcutaneous tissue of the left fore limbs were circumferentially incised at the base of the axilla. To prevent development of collateral flow, the skin edges were sutured to the underlying muscle. Thirty days after the first operation, forty rats underwent the second operations. The remaining rats remained as the control group. The second operation consisted of transplantation of a groin flap to the axilla of the left forelimb. Microsurgical techniques were used to anastomose the vascular pedicle. Groin flaps from their inguinal region ipsilateral side were transplanted to the forelimb using microsurgery technique including vessel anastomoses. The flap includes inguinal lymphnodes and measures approximately 30mmx10mm. The donor sight primarily closed at the time. The forelegs were then compared by circumference and volume every five days for a month.

Results: These studies have shown reduction in lymphedema, microscopic lymphangiogenesis, and return of lymphatic drainage. This experiment may represent a good treatment for lymphedema that involves a relatively less demanding. It may also offer great hope for patients who are struggling with lymphedema after breast cancer surgery.

Conclusion: This study proposes that free tissue transfer of a groin flap to the axilla would improve lymphatic drainage of a lymphedematous upper extremity. We are already initiating human trials for secondary lymphedema based on this hypothesis and experience.