A Pilot Cross-Over Preference Study of Two Pneumatic Compression Devices for Patients with Lower Limb Lymphedema

Introduction, Objectives, and/or Purpose: Lymphedema (LE) is tissue swelling due to lymphatic system dysfunction and excessive retention of interstitial fluid. Patients diagnosed with LE suffer from chronic swelling, pain, and are at high risk for cellulitis and wounds. The LE standard of care treatment is complete decongestive therapy (CDT), consisting of two stages. Stage one combines therapist and self-guided manual lymphatic drainage (MLD), exercise, skin care, compression bandaging and garments, and occasionally a pneumatic compression device (PCD). Stage two is mainly patient self-managed and PCDs are more routinely used. The vast majority of LE care is self-care.

PCDs surround the limb with a garment containing air-filled chambers. Newer generation PCDs have been designed to specifically impact the lymphatic system, utilizing lower pressure profiles and treatment sequences intended to simulate MLD techniques. Several studies have shown the benefit of these newer generation PCDs as an adjunctive therapy relating to reducing limb volume, improved quality of life, and reduced healthcare expenditure. However, a major drawback of current PCDs is their usability: they are large, bulky and difficult to use. While never being formally evaluated, anecdotal evidence suggests that these issues can often lead to a lack of engagement, poor usage, and/or termination of therapy.
Given the enormous burden LE patients face, and costs associated with poor management, it is desirable to better understand features that lead to greater acceptability of and adherence to self-care therapies such as PCDs. The primary objective of this pilot study was to compare subjective preference measurements of the compact Aria Health Aria Free™ and the Tactile Medical® Entre™, a traditional PCD.

Methods: This is an open label, unblinded, randomized controlled, cross-over preference pilot study to assess user preference of the Aria Free™ Pneumatic Compression System (“Aria Free”, “Aria™”) vs. the Entre for the treatment of primary and secondary LE. The study was approved by the Advarra IRB (Pro00063658). To date, 15 subjects of a planned sample size of 20, all age ≥18 years with diagnosed lower extremity LE, have been evaluated.

Subjects completed one in-clinic visit, consisting of two 30-minute therapy interventions with each device and a 30-minute washout period between the two interventions. Data collected included initial subjective device preference prior to any therapy as measured by the “Inspection Preference Questionnaire”, subjective device satisfaction as measured by the “Post-Intervention Satisfaction Questionnaire”, overall device preference as measured by the “Post-Study Preference Questionnaire”, and the clinician’s assessment of skin and tissue health.

Results: The study site was activated and began enrolling subjects June 11th, 2022. To date, 15 subjects have completed the study, no subjects have withdrawn, and no adverse events have been reported. A descriptive interim analysis on 75% of the expected sample size was conducted on the present data. Baseline Demographic and Clinical Characteristics including PCD history can be found in Table 1. All subjects were required to have a physician’s prescription for use of a PCD, per Inclusion Criteria; however, all but one subject were active users of a PCD. The one non-user had been prescribed a device just two days prior to study participation, thus a PCD was not yet acquired for use. Seventy-three percent of subjects were prescribed a PCD within the last two years and three subjects have been using a PCD for at least 15 years. Of the subjects who actively use a PCD, all completed a minimum of 30 minutes of daily therapy, and 80% completed at least 60 minutes of daily therapy sessions.

Each subject was randomized as to the order in which they use each device. For subjects with bilateral LE, the lower limb used in the study was selected by the Principal Investigator (PI). Seventy-three percent of subjects who participated, did so with their left lower limb as the “study lower limb”. All subjects were asked to complete a series of subjective questionnaires throughout their study visit.

Subjective Device Preference Before Therapy
Subjects completed the “Inspection Preference Questionnaire” while comparing the Aria and the Entre devices displayed side-by-side, prior to usage, and touching and handling the PCDs. This initial questionnaire asks the subjects to choose which PCD they would instantly prefer with regard to system size, weight, design, look, usage, and mobility; and garment fabric and breathability. To date, 10 of 15 subjects had a greater preference, upon initial inspection, for the Aria Free. While two subjects had no preference for either device.

Subjective Device Preference After Therapy
After each intervention, subjects were asked to complete eight 11-point Likert scale questions regarding their experience with the device used during that particular session. Each question is rated on a scale from 0 (unfavorable) to 10 (favorable). The Aria scored more favorable Likert scale scores of statistical significance when compared to the Entre regarding “comfort of therapy” (p=0.008), “how easy it would be to stand and walk around” (p=0.02), “comfort during therapy” (p=0.02), and “freedom to move around while on therapy” (p=0.03). No other differences between the scores were of statistical significance.

Overall Device Preference
Subjects completed the “Post-Study Preference Questionnaire”, where they were asked to report their preference of either “Aria Free”, “Entre”, or “No difference/Neither”, regarding subjective observations of limb size and softness, garment & therapy comfort, overall preference to use, ease of use, and mobility. Aria was preferred for its comfort during therapy and for garment comfort; as well as its ease to: pause, disconnect, walk and reconnect; and to walk in more easily. Ten of 15 subjects also declared preferring to use the Aria more frequently and, in general, over the Entre. Subjects did not notice a subjective difference in limb softness or size after sessions with either of the PCDs.

Clinical Assessment of Skin and Tissue Health
The PI completed a Skin & Tissue Health Assessment and evaluated the subject’s skin and tissue after each intervention and completed 20 questions with either “Yes” or “No” answers if any of the observations were present or not, respectively, during the exam. There were no significant differences between these results following the two interventions. Notably, 14 out of the 15 participants were assessed to have soft skin after both devices.

Conclusion(s): Lymphedema is an incurable, progressive condition that requires a lifetime of self-management that can be time-consuming and burdensome. People living with lymphedema are required to complete daily self-care to slow its progression and minimize complications. It has been suggested that if a person perceives their self-care treatment is helping, then they may also experience improved physical and emotional health. As discussed since the 1950s, self-care is a human regulatory function accomplished by intentional result-seeking action. The action taken is completed by the individual, without the assistance of others, to meet the individual’s own need to manage symptoms and gain control of a medical condition. Thus, lymphedema self-care omits professionally administered treatments, such as surgery or therapist-provided MLD. To these points, it is imperative that people living with lymphedema have access to self-care treatments that they can utilize daily and perceive as helpful. Aria Free (Figure 1) is a compact PCD that has recently been shown to be the smallest and lightest PCD for the lower limb on the market, as well as being effective, comfortable and easy to use. This study aims to investigate user-preference of the Aria Free as compared to a traditional PCD to better understand the patient’s reaction to the treatment delivered and overall acceptability of both devices. Ultimately, the intention is to provide this patient population with a device that would be more likely utilized, hence improving adherence, persistence, and health outcomes.

The preliminary descriptive results of this pilot study show that patients prefer the compact Aria Free over a traditional PCD. Subjects expressed preference prior to using the Aria as well as after, demonstrating their initial and continued liking of the device. Current data interpretation is performed considering limiting factors, including the small sample size, within-subjects study design, and that subjects did not operate either of the devices on their own. However, these descriptive findings are consistent with the hypothesis that subjects would prefer the Aria Free and show promise that final analyses will statistically significantly support the preference of the Aria over a traditional pneumatic compression device regarding subjective and objective measures.