A Review and Proposed Classification System for the No-Option Patient With Chronic Limb-Threatening Ischemia

Abstract

A growing, but poorly defined subset of patients with chronic limb-threatening ischemia (CLTI) have “no option” for revascularization. One notable subgroup includes patients with severe ischemia and advanced pedal artery occlusive disease, termed “desert foot,” who are at high risk for major amputation due to a lack of conventional revascularization options. Although new therapies are being developed for no-option patients with desert foot anatomy, this subgroup and the broader group of no-option patients are not well defined, limiting the ability to evaluate outcomes. Based on a systematic review, a classification of the no-option CLTI patient was constructed for use in clinical practice and studies. Several no-option conditions were identified, including type I—severe and pedal occlusive disease (desert foot anatomy) for which there is no accepted method of repair; type II—lack of suitable venous conduit for bypass in the setting of an acceptable target for bypass; type III—extensive tissue loss with exposure of vital structures that renders salvage impossible; type IV—advanced medical comorbidities for which available revascularization options would pose a prohibitive risk; and type V—presence of a nonfunctional limb. While type I and type II patients may have no option for revascularization, type III and type V patients have wounds, infection, comorbidities, or functional status that may leave them with few options for revascularization. As treatment strategies continue to evolve and novel methods of revascularization are developed, the ability to identify no-option patients in a standardized fashion will aid in treatment selection and assessment of outcomes.

One year clinical outcomes of Rutherford 6 chronic limb threatening ischemia patients undergoing lower limb endovascular revascularisation from Singapore

“…Defined by major tissue loss and gangrene, R6 is the most severe form of CLTI (Rutherford et al 1997 ). Arterial occlusive disease in R6 patients is often so severe that their lower extremities are termed “desert feet” (Kim et al 2021 ), which puts these patients at high risk for major amputation due to the lack of effective conventional revascularisation options and presence of microvascular disease. Mortality in R6 patients is also high (33.7% in 12 months).…”

Distal Endarterectomy Combined With Endovascular Proximal Treatment: The Hybrid DEEP Retrograde Technique for High-Complexity Infrainguinal Disease

“…Interestingly, this has allowed effective revascularization in some cases that had been managed nonoperatively, which is subject to a higher rate of amputation and mortality. 9,16,26 We believe that a team equally expert in endovascular and open techniques may provide the best-individualized treatment according to the patient characteristics and the lesion pattern.…”

Mesenchymal stem cell-based therapy for non-healing wounds due to chronic limb-threatening ischemia: A review of preclinical and clinical studies

“…Those with tissue ischemia and loss secondary to CLTI constitute a vulnerable group of patients who face significant risks of amputation and mortality, which are further compounded in the presence of concomitant medical comorbidities such as DM ( 8 – 10 ). There continues to be an unmet need for clinical therapies and treatments to improve outcomes in patients who fail standard medical and surgical interventions.…”

“…Treatment for CLTI consists mainly of risk factor mitigation with control of cholesterol and glycemic levels, smoking cessation, and endovascular or open surgical revascularization if feasible. Unfortunately, nearly 20–40% of patients may not respond to or have failed standard medical therapy or are unsuitable for revascularization ( 8 – 10 ). Given the high economic burden imposed on patients, decreased quality of life, and poor survival of those with CLTI, regenerative therapies aimed at the promotion of neovascularization to improve wound healing and limb salvage hold significant promise.…”

“…Moreover, numerous studies have previously reported the refractory nature of ischemic wounds associated with CLTI to treatment, and the most common local wound care regimens appear to have only a minimal impact upon the size of the overall ulcer ( 11 – 14 ). Patients with persistent disease despite optimal medical therapy and surgical revascularization or who have contraindications to surgical intervention and are deemed “no-option” face major rates of amputation (46%) and mortality (50%) at 1 year, even worse than some malignancies ( 8 – 10 ). Consequently, there is a critical unmet need for newer vascular regenerative therapies.…”