Evaluation of Stiffness in Postmastectomy Lymphedema Using Acoustic Radiation Force Impulse Imaging: A Prospective Randomized Controlled Study for Identifying the Optimal Pneumatic Compression Pressure to Reduce Stiffness.

Purpose: We aimed to assess the improvement in stiffness in patients with postmastectomy lymphedema (PMLE) after intermittent pneumatic compression (IPC) using acoustic radiation force impulse (ARFI) imaging and evaluate the effects of different IPC pressures.

Methods: We randomly assigned 45 patients with PMLE (stage II) to three groups based on the IPC pressure: 25, 35, and 45 mmHg. Patients received a single session of IPC for 30 minutes. We recorded the subcutaneous tissue thickness of the proximal upper limbs using ultrasonography and circumference of the upper limbs and stiffness using ARFI before and immediately after IPC.

Results: Arm circumference and subcutaneous tissue thickness were significantly decreased after IPC in all groups. The shear wave velocity (SWV) decreased after IPC in all groups, but significantly decreased only in the 35 mmHg group. The subcutaneous tissue thickness and SWV in the 35 mmHg group were significantly decreased compared to the other groups.

Conclusion: IPC can reduce stiffness and subcutaneous tissue thickness of the proximal upper arm in patients with PMLE. A pressure of 35 mmHg yields the largest improvement of stiffness; higher compression pressure did not yield any additional improvement.