Critical Limb Ischemia
Critical limb ischemia (CLI) is the most severe form of peripheral artery disease (PAD). PAD is associated with high rates of major lower limb amputation, myocardial infarction, and stroke. CLI’s causation is usually associated with either diabetes or long-term tobacco use, and the greatest economic healthcare burden of CLI is the management of chronic foot and leg ulcers leading to gangrene and then major limb amputation.
- Major limb amputation procedures are conducted at an annual rate of 120 to 500 per million in western countries1, and certain U.S. states have significantly higher incidence rates than others
- Major amputation occurs in 25% of patients with CLI2
- Major amputations incidence rates are higher in blacks (0.41%) than whites (0.18%) in the United States3,4
We reported Phase I/II (Feasibility) study results in January 2014. In this open label single arm study, 17 no-option CLI patients were enrolled who had exhausted all Standard of Care options and were recommended for amputation. Upon receiving the SurgWerks-CLI therapy, all patients were followed for 12 months after treatment and evaluated at three month intervals for safety and efficacy endpoints.
- SAFETY : The review board determined the primary safety objective(s) to have been met.
- Leg Survival:
- 82.4% major Amputation Free Survival after 12 months (CI = 95%)
- 70.6% minor Amputation Free Survival after 12 months (CI = 95%)
- Leg Oxygen Levels:
- TcPO2 values improved 143% to 35.75mm Hg (p=0.0032)
- ABI values improved approx. 50% (p=0.0003)
- Pain Scores:
- Claudication (walking pain) was reduced by 97% (p=0.0005)
- Rest pain was reduced to a non-detectable level at 12 months (p=0.0010)
- Six Minute Walk:
- 12 patients unable to walk on enrollment. 9 patients could walk 150 meters at 12 months (p=0.0039)
- Wound Closure:
- 13 patients had varying degrees of soft tissue pathology on enrollment, and12 patients finished the study with limited to no soft tissue ulcers or gangrene
- Each patient was assessed on enrollment using CT-angiography for both quality and quantity of limb vessels. There was a statistically significant improvement in both the size and number of vessel collaterals in the distal thigh.
- Leg Survival:
Next Development Steps
The U.S. Food and Drug Administration (FDA) has granted full approval for an Investigational Device Exemption (IDE) for the Company’s pivotal clinical trial, named the CLIRST III trial, to evaluate Cesca’s SurgWerks™-CLI and VXP System for the treatment of patients with late-stage, no-option, critical limb ischemia (CLI). Site selection is in progress and patient enrollment is expected in first half of 2016.
1 Dormandy J, Heeck L, Vig S. Major amputations: clinical patterns and predictors. Semin Vasc Surg. 1999;12(2):154–161.
2 Norgren L, Hiatt WR, Dormandy JA, Nehler MR, Harris KA, Fowkes FG;, TASC TASC II Working Group. Inter-Society Consensus for the Management of Peripheral Arterial Disease (TASC II) J Vasc Surg. 2007;45(Suppl S):S5–67.
3 Regenbogen SE, Gawande AA, Lipsitz SR, Greenberg CC, Jha AK. Do differences in hospital and surgeon quality explain racial disparities in lower-extremity vascular amputations? Ann Surg. 2009;250(3):424–431.
4 Baser O, Verpillat P, Gabriel S, Wang L; Prevalence, Incidence and Outcomes of Critical Limb Ischemia in US Medicare Population. Vascular Disease Management; Vol 10-Issue 2; Feb 2013.