This study seeks to demonstrate the effect of advanced pneumatic compression in treatment naïve patients with CEAP C3 and C4 chronic venous disease. The main questions it aims to answer are:

• Does lymphatic treatment improve lymphatic function following ~30 days of advanced pneumatic compression device therapy?
• Does lymphatic dysfunction correlate with CEAP score and venous reflux times? Over the course of 30-45 days, participants will undergo two sessions of near-infrared fluorescence lymphatic imaging to assess whether advanced pneumatic compression treatment improves lymphatic (dys)function. Subjects will be divided into two groups, a treated and a control group. Both groups will receive standard-of-care compression bandaging. The treated group will also be asked to complete daily sessions of pneumatic compression therapy at home. At both imaging sessions, duplex ultrasound will also be used to assess venous reflux times. Researchers will compare the changes in lymphatic and venous (dys)function between the two groups to see if lymphatic function improves with pneumatic compression treatment and if they dysfunction is correlated with CEAP clinical score and venous reflux times.

Inclusion Criteria:

1. Participant >18 years of age
2. Participant with an objective diagnosis of CEAP Class 3 or 4 superficial venous disease (superficial reflux time >0.5 sec), with venous edema (revised VCSS score of 2 or 3 for edema).
3. Participant must provide informed consent
4. Participant is willing and able to fulfill study timeline
5. Participant is a candidate for APCD treatment per the FTP indications
6. Lymphatic dysfunction is observed, using NIRF-LI, in affected limb.

Exclusion Criteria:

1. History of pelvic or lower extremity cancers
2. Systemic organ failure including heart failure
3. BMI >35
4. Previous endovascular or open vascular interventions
5. Patients with known, or family history of, primary lymphedema
6. Prior use of advanced pneumatic compression device, or complete decongestive therapy (CDT) on the lower extremities
7. Peripheral arterial disease with ABI <0.8
8. Participants with deep venous obstruction
9. Skin disease not related to CVD
10. Participants with iodine allergies including patients with shellfish allergy who may be allergic to iodine that may be in the ICG formulation
11. Females who are pregnant or breastfeeding
12. Females with the intent of becoming pregnant within 30 days after participation in final imaging session

Results will be published in a scientific journal along with description of protocol. The complete data set includes large (GBs) sequences of images that may include protected health information (tattoos). Partial, redacted data sets may be sharable upon request.