Objective Methods for Breast Sensibility Testing.

BACKGROUND

The breast and the factors that affect the sensitivity of the nipple-areola complex have been a significant subject of study in recent years. The main purpose of this study was to provide an objective assessment of the effect of volumetric differences on nipple-areola complex sensitivity.

METHODS

Data were collected examining the right breast of 34 female volunteers. The mechanosensitive Aβ-fiber and mechanoinsensitive C-fiber function of the nipple-areola complex was assessed after mechanical and chemical stimulation, respectively. Flare responses were elicited chemically by the application of histamine by means of iontophoresis and recorded by laser Doppler imaging. The correlation of the maximum flare area responses with the breast volume and nipple-areola complex and the response from the von Frey fiber test was estimated using linear regression analysis.

RESULTS

Nipple-areola complex area increased with breast volume and, similarly, the area of histamine-induced axon reflex flare response follows the larger nipple-areola complex. However, a larger nipple-areola complex correlated with higher local mechanical thresholds. Higher mechanical thresholds were linked to smaller axon reflex area, suggesting combined small- and thick-fiber neuropathy.

CONCLUSIONS

Objective small-fiber assessment using laser Doppler imaging and subjective mechanical threshold tests were used successfully to quantify function of Aβ and C fibers in the nipple-areola complex. Increased breast volume was linked to larger nipples, but also to impairment of Aβ and C fibers. Sensory testing can be incorporated into preoperative and postoperative management of patients undergoing breast operations to assess changes of neuronal function of the nipple-areola complex after surgery.