Axillary reverse mapping (ARM): a new concept to identify and enhance lymphatic preservation

Variations in arm lymphatic drainage put the arm lymphatics at risk for disruption during axillary lymph node surgery. Mapping the drainage of the arm with blue dye (axillary reverse mapping, ARM) decreases the likelihood of disruption of lymphatics and subsequent lymphedema.

This institutional review board (IRB)-approved study from May to October 2006 involved patients undergoing SLNB and/or ALND. Technetium sulfur colloid (4 mL) was injected in the subareolar plexus and 2-5 mL of blue dye intradermally was injected in the ipsilateral upper extremity (ARM). Data were collected on variations in lymphatic drainage that impacted SLNB or ALND, successful identification and protection of the arm lymphatics, any crossover between a hot breast node and a blue arm node, and occurrence of lymphedema.

Of the 40 patients undergoing surgery for breast cancer, 18 required an ALND, with a median age of 49.7 years old. Fourteen patients had a SLNB + ALND, and four patients had ALND alone. In 100% of patients, all breast SLNs were hot but not blue, and the false negative rate was 0. In 11 of 18 ALNDs (61%) blue lymphatics or blue nodes were identified in the axilla. In the initial seven cases with positive lymph nodes in the axilla, the blue node draining from the arm was biopsied and all were negative.

ARM identified significant lymphatic variations draining the upper extremities and facilitated preservation in all but one case. ARM added to present-day ALND and SLNB further defines the axilla and may be useful to prevent lymphedema.