The study has stopped early due to enrollment challenges related largely to the current pandemic

The primary objective of this study is to evaluate the performance of the HemaTrate™ Blood Filtration system in the treatment of critical limb ischemia. The primary endpoint measure is comparing the percentage of patients between the treatment arm and control arm who have freedom from major amputation, arterial intervention below the knee, and death through 12 months.

Inclusion Criteria:

1. Critical Limb Ischemia in the study leg with ischemic rest pain and/or ulcer/minor tissue loss (Rutherford 4 or 5)
2. Previously failed an endovascular or surgical treatment of the study lower leg and is not being considered for additional intervention within the next 3 months OR is unsuitable for revascularization

Exclusion Criteria:

1. Simultaneously participating in another investigational study (e.g., drug or device)
2. Pregnant or breastfeeding, or planning to become pregnant within the next 12 months
3. Major surgery (open cardiac, vascular, or abdominal procedure) within the past 90 days
4. Endovascular intervention within the past 30 days
5. Current dialysis, or expected to need dialysis within the next 12 months
6. Previous above the ankle amputation in the study leg

Cook Research Incorporated (CRI) is fully committed to supporting the principles of responsible data sharing, including providing qualified scientific researchers access to deidentified, patient-level data from CRI clinical studies to conduct legitimate scientific research. Data underlying the results reported in this clinical study will be made available for request after publication of the results from this study and ending 5 years after initial publication. Interested researchers may review the "Cook Research Incorporated Policy on Access to Clinical Study Data" at https://www.cookresearchinc.com/extranet/data-access.html and submit a complete research proposal to request data access. Additional study documents (such as the study protocol) will be shared as needed if the data access request is granted. A data sharing agreement will be executed for access to deidentified patient-level data.

The investigator for this study is the person that will be performing the injections throughout the study and will know the participant's treatment (TNC or saline). The investigator that is aware of the participant's treatment will not be performing the follow-up visits.