Adaptation of Axillary Reverse Mapping Using Methylene Blue Dye for the Prevention of Post-Mastectomy Lymphedema: A Low-Cost Alternative to Radiotracers.

INTRODUCTION

Post-mastectomy lymphedema is a common complication of axillary lymph node dissection (ALND). Axillary reverse mapping (ARM) aims to preserve arm lymphatics and reduce lymphedema. Radiotracer-based ARM is costly and limited in availability, whereas methylene blue dye offers a potentially low-cost alternative. The objective of this study was to evaluate the feasibility, safety, and short-term association of methylene blue-based ARM with post-mastectomy lymphedema.

MATERIALS AND

METHODS

This prospective observational study included 60 female patients undergoing mastectomy with ALND at Ziauddin Hospital over 6 months. ARM lymphatics were identified and preserved using methylene blue dye when oncologically safe. Patients were followed for 6 months; lymphedema was assessed by clinical examination and measurements of arm circumference at standardized landmarks. Statistical analyses included the Chi-square test, the independent t-test, and exploratory multivariate logistic regression adjusting for age, BMI, tumor stage, and number of lymph nodes removed.

RESULTS

ARM lymphatics were identified in 51 (85.0%) patients and preserved in 46 (90.2%). Lymphedema occurred in 2 (4.3%) patients in the ARM-preserved group versus 4 (28.6%) in the sacrificed/not-identified group (χ² = 6.37, p = 0.012). Mean arm circumference increase at 6 months was 0.7 ± 0.5 cm versus 1.6 ± 0.7 cm (t = 4.81, p < 0.001). In exploratory multivariate analysis, ARM preservation was associated with lower odds of lymphedema (adjusted OR = 0.21, 95% CI: 0.05-0.88, p = 0.032). No major adverse events were observed; however, given the limited sample size and non-systematic adverse-event monitoring, rare reactions cannot be excluded.

CONCLUSION

Methylene blue-based ARM is feasible and associated with lower lymphedema incidence and reduced arm swelling in this cohort. Findings should be interpreted cautiously due to the observational design, small sample size, short follow-up, and limited safety monitoring. These results indicate an association rather than established causal effectiveness and suggest that methylene blue may be a practical alternative to radiotracers in resource-limited settings.