Tissue Tonometry Before and After Liposuction of Arm Lymphedema Following Breast Cancer

BACKGROUND: Arm lymphedema is a common complication after breast cancer treatment. Different conservative and surgical treatments have been used to reduce the arm swelling, but most have failed as chronic edema eventually transforms from a state of accumulated lymph fluid into increased deposition of subcutaneous fat, i.e. a non-pitting lymphedema. OBJECTIVE: To evaluate changes in tissue tonicity with an electronic tissue tonometer before and after liposuction. To validate the tonometer, outcome of surgery, and aspirate content. If tonometry can discriminate between "soft" and "hard" edema/swelling, it can be used to differentiate these types, as treatment differs. SUBJECTS AND METHODS: Twenty women with non-pitting unilateral postmastectomy arm lymphedema were operated on. The following measurements were performed: Tissue tonicity with a tonometer, its sensitivity on five different foam-polyethers by ten subjects, arm volumes, and adipose tissue aspirate content. RESULTS: Tissue tonicity values showed that the upper lymphedematous arm was harder than the normal one. After surgery it became softer, and at one year it was as soft as the normal arm. Polyether tonometries could clearly differentiate the various properties. A sample of three measurements was as good as ten. Horizontal vs. vertical measurements did not differ in the high-density polyethers. Complete reduction of the lymphedema was achieved. Adipose tissue content of the aspirate was 89%. CONCLUSION: The tonometer could register postoperative changes in tissue tonicity in the upper arm, but not in the forearm, which also showed significantly higher absolute values. Probably this is caused by the high adipose tissue content with little or no free fluid, thus resembling the normal arm in tonicity. Possibly also the thinner subcutaneous tissue in the forearm plays a role. Tonometry can differentiate if a lymphedematous arm that is softer or harder than the normal one. A harder swelling is dominated by adipose tissue and can be treated with liposuction, while the softer one is treated conservatively.