Lymph-interpositional-flap transfer (LIFT) based on lymph-axiality concept: Simultaneous soft tissue and lymphatic reconstruction without lymph node transfer or lymphatic anastomosis.

[BACKGROUND] Lymphatic system is important to maintain homeostasis. Lymph-axiality concept has been reported, which suggests possibility of lymphatic reconstruction using flap transfer without lymph node or supermicrosurgical lymphatic anastomosis.

[METHODS] Medical charts of 122 free flap reconstruction cases, either with conventional flap transfer (control) or lymph-interpositional-flap transfer (LIFT), for extremity soft tissue defects including lymphatic pathways were reviewed. Lymph vessels' stumps in a flap were placed as close to those in a recipient site as possible under indocyanine green (ICG) lymphography navigation in LIFT group. LIFT group was subdivided into LIFT(+) and LIFT(-) groups; lymph vessels' stumps could be approximated within 2 cm in LIFT(+) group, whereas those could not be in LIFT(-) group. Lymph flow restoration (LFR) and lymphedema development (LED) rates were compared between the groups on postoperative 6 months.

[RESULTS] No flap included lymph node. LFR was observed in 50 cases and LED in 72 cases. LFR rate in LIFT group (n = 75) was significantly higher than that in control group (n = 47) (57.3% vs. 14.9%; P < 0.001). LED rate in LIFT group was significantly lower than that in control group (20.0% vs. 48.9%; P < 0.001). Sub-group analysis showed significantly higher LFR and lower LED rates in LIFT(+) group (n = 44) than those in LIFT(-) group (n = 31; 88.6% vs. 12.9%; P < 0.001, 4.5% vs. 41.9%; P < 0.001).

[CONCLUSIONS] LIFT allows simultaneous soft tissue and lymphatic reconstruction without lymph node transfer or lymphatic anastomosis, which prevents development of secondary lymphedema.