Z42 - Measuring the Pressure Exerted on the Body by Surgical Bras

Introduction: : A surgical bra is a medical garment worn after procedures such as mastectomy and breast reconstruction. Surgical bras entered the market in the 1970s, but their design has not been optimized for clinical outcomes. Compression, a key feature of surgical bras, is defined as a reduction in volume from the act of physical pressure pushing something into a smaller space. Pressure is the physical force per unit area that is exerted on the object. Compression after surgery provides clinically important reduction in scar hypertrophy, pain, and itching. However, the amount, distribution, and duration of pressure that a surgical bra should exert on the body to promote recovery after breast surgery is unknown.

Materials and

Methods: : Previous research has identified the optimal pressure to be exerted by a compression sleeve for managing hypertrophic burn scars on the forearm. In contrast, while many brands claim their surgical bras offer compression using pressure gradients, they do not provide pressure ranges with directions on when and how the garments should be used. The goal of this project is to develop an evidence-based protocol for measuring the pressure exerted on the body by surgical bras. Our approach is informed by methods used to optimize the compressive properties of other medical garments, the literature on pertinent non-medical garments (e.g., sports bras), and prior work investigating stakeholders’ needs for surgical bras.

Results, Conclusions, and Discussions:: Estimating the pressure that a surgical bra will exert on the body requires knowledge of the stiffness of the fabric from which the surgical bra is constructed. Our protocol uses the ASTM D5034 grab method. By pulling a fabric until it fails, we can collect force and elongation data for calculating the stress, strain, and the maximum force. The maximum force can then be used to set the breaking point for the ASTM D5034 tester, to retrieve linearity, percent elongation, tensile energy, tensile resistance and elastic recovery of the surgical bra fabric.

In addition to using modeling to estimate the pressure that will be exerted by the surgical bra on the body, our protocol includes direct mechanical testing. Small, flexible pressure sensors should be used on soft breast tissue to allow the sensor to make full contact with the surface area. Considering prior data on pressures exerted on the body by similar garments, sensors that can measure pressures in the range of 0.5-15 kPA should be used for evaluating surgical bras. Informed by need assessment studies, the sensors should be placed at key anatomical locations such as the inframammary fold and shoulder strap regions.

Surgical bras must accommodate changes in the position of the body. Our protocol specifies mechanical testing in several common postures, including sitting, standing, and supine. Similarly, surgical bras need to accommodate repeated wear over time. Hence, our protocol calls for the assessment of pressure-time curves.

Our protocol for measuring the pressure exerted on the body by surgical bras will contribute to standardized assessment of surgical bras. Our protocol will lay the groundwork for optimizing the amount, distribution, and duration of pressure that a surgical bra should exert on the body to promote recovery after breast surgery.

Acknowledgements and/or References (Optional):: ALL is currently a Fellow supported by T32 EB007507.