Lymphatic System Response to Severe Lower Limb Trauma

BACKGROUND: Patients with severe compound lower limb trauma who undergo complex soft tissue reconstruction are at risk of lymphoedema. Oedema, a sign of lymphatic failure, is a significant contributory factor towards the morbidity of patients with lower limb reconstructions.

OBJECTIVE: To investigate lymphatic response to soft tissue reconstruction for Gustilo IIIB compound lower limb trauma.

DESIGN: Patients were recruited from a lower limb trauma database from the department of Plastic and Reconstructive Surgery at the Royal Adelaide Hospital in South Australia. All patients who suffered Gustilo IIIB compound lower limb trauma between 2007 and 2013 and underwent reconstruction with either free of locoregional flaps were considered for recruitment. Consenting participants were measured for presence of local and whole limb oedema, local epifascial fluid changes & tissue induration. Patient rated outcomes and quality of life were determined on the basis of response to Short Quality of Life questionnaire and Lower Extremity Functioning score. Clinical imaging of the lymphatic system was performed using Indocyanine Green (ICG) with Near Infrared imaging camera. Two intradermal ICG injections (0.1-0.2 mL) on the dorsal side of each foot were sufficient for superficial lymphatic mapping. All measurements were repeated on their non-affected leg which acts as a control.

RESULTS: To date we have enrolled 3 females and 11 males whose reconstructive surgery was performed between 2009-2013. Their age range was 25-72 with a median BMI of 30.9. A significant difference was found in the presence of local tissue fluid between the reconstructed area and a similar area on the control leg. Bio Impedance Spectroscopy, which measures the fluids specifically, showed a trend in fluid distribution of the affected leg versus the control leg. QOL and patient rated outcomes demonstrate impairment in daily function with presence of pain, swelling in or distal of the reconstructed site and a reduced capability of participating in sports and running activities.

In most cases we have observed no lymphatic flow from the distal extremity into the flap, and this is associated with dermal backflow patterns around the flap area. Slower uptake of ICG in the affected leg and altered anatomical pathways suggest adaption of the lymphatic system by creating anastomosis. The patterns observed are similar to those previously published by the Japanese group

(Yamamoto et al 2011).

CONCLUSION: We have demonstrated that severe compound lower limb trauma as well as the subsequent reconstructive methods constitute potential obstructions for normal lymphatic flow. The findings of this study improves our understanding of lymphatic repair after severe soft tissue trauma and improves awareness of the high risk of lymphoedema in this population. It is hoped that with further study, early detection and understanding of the nature of lymphatic damage will help implement preventive measures and early, targeted treatment to this patient group.