Lymph node content of supraclavicular and thoracodorsal-based axillary flaps for vascularized lymph node transfer.

Objective: Microvascular transfer of lymph node flaps has recently gained popularity as a treatment for secondary lymphedema often occurring after axillary, groin, or pelvic lymph node dissections. This study aimed to delineate the lymph node contents and pedicle characteristics of the supraclavicular (SC) and thoracodorsal (TD)-based axillary flaps as well as to compare lymph node quantification of surgeon vs pathologist.

Methods: SC and TD flaps were dissected from fresh female cadavers. The surgeon assessed pedicle characteristics, lymph node content, and anatomy. A pathologist assessed all flaps for gross and microscopic lymph node contents. The κ statistic was used to compare surgeon and pathologist.

Results: Ten SC flaps and 10 TD flaps were harvested and quantified. In comparing the SC and TD flaps, there were no statistical differences between artery diameter (3.1 vs 3.2 mm; P = .75) and vein diameter (2.8 vs 3.5 mm; P = .24). The TD flap did have a significantly longer pedicle than the SC flap (4.2 vs 3.2 cm; P = .03). The TD flap was found to be significantly heavier than the SC flap (17.0 ± 4.8 vs 12.9 ± 3.3 g; P = .04). Gross lymph node quantity was similar in the SC and TD flaps (2.5 ± 1.7 vs 1.8 ± 1.2; P = .33). There was good agreement between the surgeon and pathologist in detecting gross lymph nodes in the flaps (SC κ = 0.87, TD κ = 0.61).

Conclusions: The SC and TD flaps have similar lymph node quantity, but the SC flap has higher lymphatic density. A surgeon's estimation of lymph node quantity is reliable and has been verified in this study by comparison to a pathologist's examination.