The goal of this single-arm clinical trial is to learn whether overnight limb elevation using the UZit® device can improve symptoms and signs of chronic venous disease (CVD) in adults. The main questions it aims to answer are:

Does one week of overnight UZit® use improve quality of life in patients with CVD? Does UZit® use reduce ankle circumference and are there any adverse events associated with its use? Because there is no comparison group, all participants will use the UZit® device to determine whether these effects occur.

Participants will:

Use the UZit® device every night for one consecutive week. Follow their vascular surgeon's existing recommendations (e.g., compression stockings, venotonic medications).

Complete the CIVIQ-14 questionnaire at baseline and after one week of using the device to assess quality of life.

Measure ankle circumference twice daily (upon waking and before bedtime) using a digital tape measure, following marked anatomical points.

Report any symptoms-including low back pain-and rate their satisfaction with the device on a 0-5 scale.

This single-arm clinical trial evaluates the effect of limb elevation with UZit®. Participants were invited to use UZit® overnight for one consecutive week to improve symptoms and signs of CVD of the lower limbs. UZit® (PPP-118717; technical Data Sheet in Supplementary Data 1) is an inflatable wedge-shaped device made of thermoplastic polyurethane (Figure 1), placed under a traditional mattress. When inflated, it creates an inclined plane of approximately 5%, optimizing venous circulation during rest. By evenly inclining the entire body, it avoids lumbar spine movement regardless of sleeping position. In addition to leg elevation, patients were advised to follow all other recommendations from their vascular surgeon (e.g., use of compression stockings, venotonic medications, etc.). The primary outcome was quality of life in CVD patients, assessed with the Portuguese translation of the CIVIQ-14 questionnaire, a validated and sensitive tool for detecting CVD-related changes. Patients completed the questionnaire at baseline and after one week of overnight UZit® use. Secondary outcomes included ankle circumference and adverse events. Ankle circumference was measured twice daily-immediately after waking and before bedtime-just above the malleolus, using a "Smart Tape Measure Body" digital device (resolution 0.1 cm, accuracy ±2%). Measurement points were marked on the skin with an "Edding 3000" marker, which patients refreshed daily. Participants were specifically asked about low back pain during limb elevation and any other symptoms during the intervention and the level of satisfaction using a scale from 0 to 5.

Inclusion Criteria:

• Patients recruited from the outpatient setting of Casa de Saúde da Boavista, where they were evaluated due to worsening of their CVD symptoms

Exclusion Criteria:

• Peripheral artery disease
• Congestive heart failure
• Gastroesophageal reflux
• Inability to provide informed consent.