Dissolved Oxygen Dressing to Improve Chronic Wound Healing After Revascularization for Critical Limb Ischemia

A Prospective, Randomized, controlled pilot study enrolling up to 50 subjects at a singe
investigational site in the US. Subjects with atherosclerotic peripheral arteria disease
(PAD) presenting with critical limb ischemia (CLI) and one or more non-healing lower
extremity arterial insufficiency ulcers who are suitable candidates for revascularization
procedures (endovascular or surgical) will be randomized 1:1 to:

- Wound care with the use of OxyGenesys(TM) Dissolved Oxygen Dressing, or

- Standard Wound Care procedures

An initial study phase will enroll up to 20 subjects (10 in each arm). Pending results of
the initial study phase, the study may continue to enroll until up to 50 subjects (25 in
each arm) have been enrolled.

All subjects will be followed clinically and receive wound evaluation at 1, 3, and 6 months.

Inclusion Criteria:

- Male or non-pregnant female >=21 years of age

- A clinical diagnosis of critical limb ischemia (CLI) with Rutherford classification
stage 5

- One or more chronic ulcers with a presumed etiology of arterial insufficiency and
duration >2 weeks. The target ulcer is defined as the highest-grade ulcer (Wagner's
classification) at initial evaluation. For wounds with identical grading, the largest
wound is the index wound

- The patient or legally authorized representative is willing to provide informed
consent and comply with specified follow-up evaluations

- Undergoing intervention for infrainguinal or infrapopliteal artery disease (below the
femoral artery bifurcation and above the ankle joint)

- The index procedure resulted in successful revascularization. For endovascular
procedures, successful revascularization is defined as complete revascularization of
the target ulcer culprit vessels according to the angiosome treatment strategy, with
a final percent diameter stenosis >50% and improved distal flow by angiography
following the procedure. For surgical procedures, successful revascularization is
defined as a patent graft and improved distal flow following the procedure.

Exclusion Criteria:

- Pregnant or nursing patients and those who plan pregnancy in the period up to 1 year
following index procedure. Female patients of child-bearing potential must have a
negative pregnancy test done within 7 days prior to index procedure.

- Rutherford classification stage 0,1,2,3,4, or 6

- Target wound duration <2 weeks

- Presence of frank gangrene (Wagner classification grade 4 or 5), major tissue loss
(severe/extensive necrosis), or unsalvageable limb (extensive ischemic ulceration
beyond the transmetatarsal level anticipated to require major amputation after the
index procedure)

- Previous or planned surgical or interventional procedure within 6 months before or 30
days after the index procedure, or any previous or planned target limb amputation.

- Active local or systemic infection

- Patients with ulcers judged by the examining physician to have a primary etiology
other than ischemic arterial disease (e.g., venous related, decubitus, or other
[goug, pyoderma gangrenosum, necrobiosis lipoidica, vitamin B12 deficiency])

- Renal failure or chronic kidney disease with estimated glomerular filtration rate
(eGFR <30 ml/min/1.7sm sq. within 30 days of the index procedure or treated with
dialysis)

- Severly decreased cardiac output

- Uncontrolled hyperglycemia

- Patients with a known other medical illness or known history of substance abuse that
may cause non-compliance with the protocol, confound data interpretation, or is
associated with a life expectancy of less than 1 year

- Patient is currently participating (or has participated in the last 30 days) in a
study of any other investigational treatment.

- Ulcer treatment with normothermic or hyperbaric oxygen therapy, recombinant or
autologous growth factor products, or use of enzymatic debridement

- Concomitant medications such as corticosteroids, immunosuppressive medications, or
chemotherapy

- Acute thrombus in the target limb