Quality of life in patients with no-option critical limb ischemia underlines the need for new effective treatment

A subpopulation of tissue remodeling monocytes stimulates revascularization of the ischemic limb

Despite decades of effort aimed at developing clinically effective cell therapies, including mixed population mononuclear cells, to revascularize the ischemic limb, there remains a paucity of patient-based studies that inform the function and fate of candidate cell types. In this study, we showed that circulating proangiogenic/arteriogenic monocytes (PAMs) expressing the FcγIIIA receptor CD16 were elevated in patients with chronic limb-threatening ischemia (CLTI), and these amounts decreased after revascularization. Unlike CD16-negative monocytes, PAMs showed large vessel remodeling properties in vitro when cultured with endothelial cells and smooth muscle cells and promoted salvage of the ischemic limb in vivo in a mouse model of hindlimb ischemia. PAMs showed a propensity to migrate toward and bind to ischemic muscle and to secrete angiogenic/arteriogenic factors, vascular endothelial growth factor A (VEGF-A) and heparin-binding epidermal growth factor. We instigated a first-in-human single-arm cohort study in which autologous PAMs were injected into the ischemic limbs of five patients with CLTI. Greater than 25% of injected cells were retained in the leg for at least 72 hours, of which greater than 80% were viable, with evidence of enhanced large vessel remodeling in the injected muscle area. In summary, we identified up-regulation of a circulatory PAM subpopulation as an endogenous response to limb ischemia in CLTI and tested a potentially clinically relevant therapeutic strategy.

Quality of Life in Patients With Chronic Limb-Threatening Ischemia Treated With Revascularization

BACKGROUND

In the BEST-CLI trial (Best Endovascular Versus Best Surgical Therapy for Patients With Chronic Limb-Threatening Ischemia), a prespecified secondary objective was to assess the effects of revascularization strategy on health-related quality of life (HRQoL).

METHODS

Patients with chronic limb-threatening ischemia were randomized to surgical bypass (Bypass) or endovascular intervention (Endo) in 2 parallel trials. Cohort 1 included patients with single-segment great saphenous vein; cohort 2 included those lacking suitable single-segment great saphenous vein. HRQoL was assessed over the trial duration using Vascular Quality-of-Life (VascuQoL), European Quality-of-Life-5D (EQ-5D), the Short Form-12 (SF-12) Physical Component Summary (SF-12 PCS), SF-12 Mental Component Summary (SF-12 MCS), Utility Index Score (SF-6D R2), and numeric rating scales of pain. HRQoL was summarized by cohort and compared within and between groups using mixed-model linear regression.

RESULTS

A total of 1193 and 335 patients in cohorts 1 and 2 with a mean follow-up of 2.9 and 2.0 years, respectively, were analyzed. In cohort 1, HRQoL significantly improved from baseline to follow-up for both groups across all measures. For example, mean (SD) VascuQoL scores were 3.0 (1.3) and 3.0 (1.2) for Bypass and Endo at baseline and 4.7 (1.4) and 4.8 (1.5) over follow-up. There were significant group differences favoring Endo when assessed with VascuQoL (difference, -0.14 [95% CI, -0.25 to -0.02]; P=0.02), SF-12 MCS (difference, -1.03 [95% CI, -1.89 to -0.18]; P=0.02), SF-6D R2 (difference, -0.01 [95% CI, -0.02 to -0.001]; P=0.03), numeric rating scale pain at present (difference, 0.26 [95% CI, 0.03 to 0.49]; P=0.03), usual level during previous week (difference, 0.26 [95% CI, 0.04 to 0.48]; P=0.02), and worst level during previous week (difference, 0.29 [95% CI, 0.02 to 0.56]; P=0.04). There was no difference between treatment arms on the basis of EQ-5D (difference, -0.01 [95% CI, -0.03 to 0.004]; P=0.12) or SF-12 PCS (difference, -0.41 [95% CI, -1.2 to 0.37]; P=0.31). In cohort 2, HRQoL also significantly improved from baseline to the end of follow-up for both groups based on all measures, but there were no differences between Bypass and Endo on any measure.

CONCLUSIONS

Among patients with chronic limb-threatening ischemia deemed eligible for either Bypass or Endo, revascularization resulted in significant and clinically meaningful improvements in HRQoL. In patients with an available single-segment great saphenous vein for bypass, but not among those without one, Endo was statistically superior on some HRQoL measures; however, these differences were below the threshold of clinically meaningful difference.

Superficial venous arterialization with the great saphenous vein in situ: a single-center experience

Background

Arterialization of the dorsal venous arch of the foot is a technique indicated in cases of critical lower limb ischemia that do not have a distal bed that is adequate to enable conventional treatment such as revascularization, angioplasty, or clinical treatment.

Objectives

The purpose of this study is to present the result of arterialization of the venous arch of the foot in 16 patients who underwent treatment with this technique.

Methods

This is a cross-sectional retrospective descriptive analytical study based on a review of the medical records of 16 patients who underwent arterialization of the dorsal venous arch of the foot for limb salvage from January 2016 to January 2021.

Results

Four (25%) of the 16 patients who underwent arterialization of the venous arch of the foot underwent a major amputation during the same hospital stay and one patient (6.25%) had a major amputation within 6 months. The other 11 patients (68.75%) had their limbs preserved, with 10 undergoing minor amputations (toes and forefoot) and one patient having no additional procedures.

Conclusions

We conclude that the technique of arterialization of the dorsal venous arch of the foot should be considered in selected cases. It is a valid alternative for limb salvage when conventional treatment is impossible.

Comparison of Transcatheter Arterialization of Deep Veins to Standard of Care in Patients with No-Option Chronic Limb Threatening Ischemia

BACKGROUND

Patients with no-option chronic limb-threatening ischemia (no-option CLTI) have limited therapeutic options. The PROMISE II study evaluated, transcatheter arterialization of deep veins (TADV) as a treatment option for no-option CLTI. In the current study patients from PROMISE II were compared to patients from a registry of untreated no-option CLTI patients (CLariTI: Natural Progression of High-Risk Chronic Limb-Threatening Ischemia).

METHODS

We used propensity matching to compare patients from the PROMISE II prospective study of the TADV intervention with simultaneously enrolled CLTI patients that were note candidates for PROMISE II but were enrolled in to CLariTI natural history registry. Untreated no-option CLTI (CLariTI) patients could either be no-option or patients who did not meet PROMISE II entry criteria. Risk difference between groups was calculated using common risk difference and P values were provided by propensity-score stratified Mantel-Haenszel test. The primary endpoint was amputation-free survival (AFS).

RESULTS

Diabetes was present in over 75% of patients. All patients had tissue loss and 35-46% had extensive tissue loss (Rutherford 6). The unadjusted AFS at 6 months, was 66.1% by Kaplan-Meier estimate for PROMISE II patients (n = 105) compared to 39.1% in the no-option cohort of CLariTI (n = 121) and 44.0% in the full cohort (no-option and patients not meeting entry criteria combine, n = 180). The treatment group who underwent TADV for no-option CLTI had an absolute difference of 29% improved (P < 0.0001) propensity-adjusted risk difference in AFS and a relative event rate reduction of 45% compared to the no-option control patients.

CONCLUSIONS

Transcatheter arterialization of deep veins (TADV) resulted in improved 6 month AFS in no-option CLTI patients and appears to be a promising therapy in patients with no-option CLTI.

Primary results of the SAVAL randomized trial of a paclitaxel-eluting nitinol stent versus percutaneous transluminal angioplasty in infrapopliteal arteries

BACKGROUND

Effective and durable options for infrapopliteal artery revascularization for patients with chronic limb-threatening ischemia (CLTI) are limited.

METHODS

The SAVAL trial is a prospective, multicenter, randomized trial of patients with CLTI and infrapopliteal artery lesions with total lesion length ⩽ 140 mm, stenosis ⩾ 70%, and Rutherford category 4-5 assigned 2:1 to treatment with the SAVAL self-expandable paclitaxel drug-eluting stent (DES) or percutaneous transluminal angioplasty (PTA) with an uncoated balloon. The primary effectiveness endpoint was primary vessel patency (i.e., core lab-adjudicated duplex ultrasound-based flow at 12 months in the absence of clinically driven target lesion revascularization or surgical bypass of the target lesion). The primary safety endpoint was the 12-month major adverse event (MAE)-free rate; MAEs were defined as a composite of above-ankle index limb amputation, major reintervention, and 30-day mortality. The endpoints were prespecified for superiority (effectiveness) and noninferiority (safety) at a one-sided significance level of 2.5%.

RESULTS

A total of 201 patients were enrolled and randomly assigned to treatment (N = 130 DES, N = 71 PTA). Target lesion length was 68.1 ± 35.2 mm for the DES group and 68.7 ± 49.2 mm for the PTA group, and 31.0% and 27.6% of patients, respectively, had occlusions. The 12-month primary patency rates were 68.0% for the DES group and 76.0% for the PTA group (Psuperiority = 0.8552). The MAE-free rates were 91.6% and 95.3%, respectively (Pnoninferiority = 0.0433).

CONCLUSION

The SAVAL trial did not show benefit related to effectiveness and safety with the nitinol DES compared with PTA in infrapopliteal artery lesions up to 140 mm in length. Continued innovation to provide optimal treatments for CLTI is needed. (ClinicalTrials.gov Identifier: NCT03551496).

Peripheral Artery Disease: Underappreciated Impact and Residual Cardiovascular Risk Despite Revascularization

This Commentary highlights the under-recognized prevalence and heavy burden of peripheral artery disease (PAD) and its important role as a harbinger of complications of atherosclerotic cardiovascular disease. Although increasing in prevalence globally, PAD is being further accelerated with diabetes, and patients with advanced PAD are at high risk for chronic limb-threatening ischemia. The need for (repeated) revascularization and amputation places a heavy social burden on patients and family, and a heavy financial burden on the health care system, exceeding the cost of coronary artery and cerebrovascular diseases. Clinical trial research in PAD will be enhanced by widely agreed-upon definitions of major adverse cardiovascular events and major adverse limb events. Antithrombotic and lipid-lowering therapies are recommended but underutilized, while the optimal peri-interventional antithrombotic regimen is still under debate. Additional antiinflammatory treatment is currently an unaddressed strategy in the management of patients with PAD, and there is a strong case for the evaluation of widely available antiinflammatory agents such as colchicine.

Disease Specific Health Related Quality of Life in Patients With Chronic Limb Threatening Ischaemia Undergoing Revascularisation of Femoropopliteal Lesions

OBJECTIVE

Patients with chronic limb threatening ischaemia (CLTI) suffer from pain and non-healing ulcers, which impact negatively on both their physical and mental health. While maintaining and improving quality of life is a principal aim with all treatments, little is known about the health related quality of life (HRQoL) of CLTI patients and how revascularisation procedures impact on HRQoL endpoints. The aim of this study was to investigate disease specific HRQoL before and after revascularisation in patients with CLTI undergoing femoropopliteal revascularisation.

METHODS

HRQoL was prospectively analysed in 190 CLTI patients with main atherosclerotic target lesions in the femoropopliteal segment, who were planned for endovascular or open revascularisation. The choice of revascularisation method was made by the vascular team, represented by both open and endovascular expertise. The Vascular Quality of Life (VascuQoL) questionnaire was used to assess disease specific HRQoL before revascularisation and one month, one year, and two years after the procedure. Main endpoints were mean VascuQoL score changes, effect sizes of observed changes and the proportion reaching a minimally important difference (half a standard deviation change from baseline) during two years after revascularisation.

RESULTS

Patient reported VascuQoL scores were low at baseline (mean 2.68, 95% CI 1.18 - 4.17). After revascularisation, the mean VascuQoL score improved statistically significantly over time, with the largest improvement observed after one year (difference from baseline 2.02, 95% CI 1.75 - 2.29; p < .001). No differences in HRQoL change over time were observed between patients treated with endovascular approaches compared with bypass surgery. Approximately half the patients reached the minimally important threshold at one year (53%), which was largely maintained also at two years (41%).

CONCLUSION

While CLTI profoundly affected HRQoL, a large and clinically meaningful HRQoL increase was observed after revascularisation. This confirms the value of CLTI revascularisation on HRQoL and underlines the importance of including patient reported outcomes when evaluating revascularisation procedures in CLTI patients.

Relationship between WIfI stage and quality of life at revascularization in the BEST-CLI trial

OBJECTIVE

The WIfI (Wound, Ischemia, foot Infection) stage measures the extent of wounds, ischemia, and foot infection in patients with chronic limb threatening ischemia (CLTI) and has been associated with the risk of major amputation. Patients with CLTI have impaired health-related quality of life (HRQoL), which can be multifactorial. We hypothesized that the severity of the limb threat (WIfI stage) would be associated with poor HRQoL among patients with CLTI presenting for revascularization.

METHODS

The dataset of the BEST-CLI (best endovascular versus best surgical therapy in patients with CLTI) trial, a prospective, randomized trial comparing open and endovascular revascularization strategies, was queried for HRQoL assessments at patient enrollment. The HRQoL assessments included (1) Vascular Quality of Life; (2) 12-item short form survey (SF-12), containing the utility index score (short-form six-dimension R2 utility index, incorporating physical, emotional, and mental well-being) and mental and physical components; and (3) the EQ-5D. Multivariable regression analysis was used to identify the independent associations with the baseline HRQoL assessments.

RESULTS

A total of 1568 patients with complete WIfI data were analyzed, of whom 71.5% were men. The WIfI distribution was 35.5% with stage 4, 29.6% with stage 3, 28.6% with stage 2, and 6.3% with stage 1. Patients presenting with WIfI stage 4, compared with stage 1 to 3, were more often men (74.9% vs 69.6%) and current smokers (25.4% vs. 17.6%), had had end-stage renal disease (13.3% vs 8.5%) and diabetes (83.6% vs 60.2%), were not independently ambulatory (56.8% vs 38.5%), and had had higher median morbidity scores (4 vs 3; P < .05 for all). On multivariable analysis, WIfI stage 4, compared with stage 1 to 3, was associated with lower SF-12 mental component scale scores (estimate, -2.43; 95% confidence interval, -3.73 to -1.13; P < .001) and short-form six-dimension R2 utility index scores (estimate, -0.02; 95% confidence interval, -0.03 to 0.001; P = .04). The WIfI stage was not independently associated with the baseline Vascular Quality of Life, SF-12 physical component scale, or EQ-5D assessments.

CONCLUSIONS

WIfI stage was independently associated with poorer quality of life because of mental, rather than physical, health for patients with CLTI. Clinicians should be aware of the burden of mental stress borne by those with the greatest limb impairment.

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

Background

Percutaneous transluminal angioplasty (PTA) is widely used as a first-line revascularisation option in patients with chronic limb threatening ischemia (CLTI). This study aimed to evaluate the short-term endovascular revascularisation treatment outcomes of a cohort of Rutherford 6 (R6) CLTI patients, from a multi-ethnic Asian population in Singapore.

Patients with R6 CLTI who underwent endovascular revascularisation from June 2019 to February 2020 at Singapore General Hospital, a tertiary vascular centre in Singapore, were included and followed up for one year. Primary outcome measures included number and type of reinterventions required, 3-, 6- and 12-month mortality, 6- and 12-month amputation free survival (AFS), wound healing success and changes in Rutherford staging after 3, 6 and 12 months.

Results

Two hundred fifty-five procedures were performed on 86 patients, of whom 78 (90.7%) were diabetics, 54 (62.8%) had coronary artery disease (CAD) and 54 (62.8%) had chronic kidney disease (CKD). 42 patients (48.8%) required reintervention within 6 months. Multivariate analysis revealed that the presence of CAD was a significant independent predictor for reintervention. Mortality was 15.1%, 20.9% and 33.7% at 3, 6 and 12 months respectively. AFS was 64.0% and 49.4% at 6 and 12 months. Inability to ambulate, congestive heart failure (CHF), dysrhythmia and CKD were significant independent predictors of lower 12-month AFS.

Conclusions

PTA for R6 CLTI patients was associated with relatively high mortality and reintervention rates at one year. CAD was an independent predictor of reintervention. More research is required to help risk stratify which CLTI patients would benefit from an endovascular-first approach versus conservative treatment or an immediate major lower extremity amputation policy.

Factors Associated with Lower Preoperative Quality of Life in Patients with Chronic Limb Threatening Ischemia in the BEST-CLI Trial

OBJECTIVES

There is limited contemporary data regarding health-related quality of life (HRQOL) measures in patients with chronic limb-threatening ischemia (CLI).

METHODS

The Best Endovascular versus Best Surgical Therapy in Patients with CLI (BEST-CLI) trial is an ongoing, NIH-sponsored, multicenter, randomized controlled trial comparing revascularization strategies in patients with CLI. BEST-CLI baseline HRQOL measures were evaluated for patient-specific variables that were associated with poor HRQOL and then compared with published outcomes. The HRQOL measures VascQOL (Vascular Quality of Life Questionnaire), EQ-5D (EuroHRQOL 5D), and SF-12 Index, physical component (PCS) and mental component (MCS) scores were aggregated from preoperative questionnaires completed by trial subjects at baseline visits. Multivariable linear regression models were fit to determine which baseline characteristics were associated with poor HRQOL.

RESULTS

1830 subjects were randomized into BEST-CLI. The majority (94.9%, 95.8%, and 95.8%) completed the VascQOL, EQ5D, and SF-12 instruments at baseline. In VascQOL, female sex, smoking history, opioid use, and non-independent ambulation predicted lower HRQOL scores. Overall, VascuQOL scores were similar to those of participants in the Bypass versus Angioplasty in Severe Ischemia of the Leg (BASIL) [(3.07(1.2)) vs 2.9(1.1)), P=.07]. In EQ5D, non-independent ambulation predicted lower HRQOL scores. In SF-12, female sex, opioid use, non-independent ambulation and history of smoking predicted lower HRQOL scores. The mean (standard deviation) SF-12 PCS for all patients in the study was 33.0(8.5) and for MCS was 46.4(12.0), significantly lower than the national SF-12 scores for US population over 60 years of age which is PCS of 46.5(11.4) and MCS of 52.9 (8.7).

CONCLUSIONS

Patients with CLI entering the BEST-CLI trial have very low HRQOL scores comparable to patients suffering from other chronic conditions characterized by physical limitation and chronic pain. A history of smoking, impaired ambulation, opioid use, and female sex predicted lower HRQOL in CLI patients, using multiple HRQOL measurement tools.

Early Experience with Venous Arterialization for Limb Salvage in No-Option Patients with Chronic Limb-Threatening Ischemia

OBJECTIVES

Chronic limb-threatening ischemia (CLTI) is associated with adverse limb outcomes and increased mortality. In a small subset of the CLTI population, there are no feasible conventional means of revascularization. In such cases, venous arterialization (VA) provides an alternative for limb salvage. The objective of this study was to review the outcomes of venous arterialization (VA) at our institution.

METHODS

This is a single institution review of 41 patients followed prospectively who underwent either superficial or deep VA. Data collected included: patient demographics, co-morbidities, VA technique (endovascular vs. hybrid) and WIfI (wound ischemia foot infection) limb staging. Data were collected at 1 month, 6 months and 1-year intervals and included the following outcomes: patency, wound healing, major adverse limb event (MALE), major amputation and death. Descriptive statistics were used for analysis.

RESULTS

The study group includes 41 patients who underwent successful open hybrid superficial or deep endovascular VA; 21 (51.2%) underwent a purely endovascular procedure and 20 (48.8%) had hybrid VA. The WIfI clinical stages were as follows: 33 (80.5%) stage 4, 6 (14.6%) stage 3, and 1 (2.4%) stage 2. Twenty-four (58.5%) patients completed follow-up at 6 months and 16 (39%) at 1 year. VA primary patency at 12 months was 28.6% (95% CI 0.15-0.43), primary assisted patency at 12 months was 44.3% (95% CI 0.27-0.60) and secondary patency at 12 months was 67% (95% CI 0.49-0.80). Complete wound healing rates were 2.7% (1) at 1 month; 62.5% (15) at 6 months; and 18.8% (3) at 1 year. Overall wound healing at 1 year was 46.3% (19). MALE rate at 1 year was 36.5% (15) comprised of 19.5% (8) re-interventions and 17% (7) major amputations. There were 0 (0%) deaths at 1 month and 4 (19%) deaths at 6 months; 2 (9.5%) deaths were attributed to COVID-19. There were no further deaths within 1 year. The limb salvage survival probability at 1 year was 81%.

CONCLUSIONS

These findings suggest that for a select subset of CLTI patients presenting with high WIfI clinical limb stage CLTI and no viable options for conventional open or endovascular arterial revascularization, superficial and deep venous arterialization are feasible options to achieve limb salvage.

Effects of Lower Limb Revascularization on the Microcirculation of the Foot: A Retrospective Cohort Study

Background: Current assessment standards in chronic limb-threatening ischemia (CLTI) focus on macrovascular function while neglecting the microcirculation. Multispectral near-infrared spectroscopy (NIRS) provides hemodynamic characteristics of the microcirculation (i.e., capillaries) and may be a powerful tool for monitoring CLTI and preventing extremity loss. The aims of this study were to (1) investigate the effects of lower limb revascularization on the microcirculation and (2) determine if macrovascular and microvascular assessments correlate. Methods: An observational, retrospective cohort study of 38 endovascular interventions in 30 CLTI subjects was analyzed pre- and post-intervention for arterial Doppler acceleration times (AcT; macrovascular) and NIRS metrics (microvascular). Pre-intervention ankle-brachial index (ABI) was also analyzed. Results: AcT significantly decreased (p = 0.009) while oxyhemoglobin (HbO) significantly increased (p < 0.04) after endovascular intervention, indicating treatment efficacy. However, macrovascular measurements (ABI, AcT) and NIRS metrics of oxygenation and perfusion did not correlate (p > 0.06, r2 < 0.15, n = 23) indicating that macro- and microvascular assessment are not congruent. Conclusion: These findings suggest that macrovascular and microvascular assessments can determine interventional efficacy in their corresponding vasculature. Their lack of correlation, however, suggests the need for simultaneous assessment as independent use may cause diagnostic information to be missed.

Eligibility of Patients with Chronic Limb Threatening Ischemia for Deep Venous Arterialization

OBJECTIVES

Percutaneous deep venous arterialization (pDVA) has emerged as a new modality for limb salvage in patients with chronic limb threatening ischemia (CLTI) and no standard option for revascularization. The proportion of patients facing major amputation that are eligible for this technology remains unknown. This study aims to provide a real-life estimate of patient eligibility for pDVA to reduce major amputations.

METHODS

Electronic medical records of 100 consecutive patients with peripheral arterial disease (PAD) who underwent major amputation of 106 limbs were reviewed. Angiograms performed ≤6 months before amputation were assessed by two vascular surgeons. Disease severity was categorized using the Global Limb Anatomic Staging System and patients were classified as ideal, possible, or not candidates for pDVA. Ideal candidates had ≥1 patent tibial artery, no target in the foot, and no proximal disease. Possible candidates had ≥1 patent tibial artery with PAD, no target in the foot, and proximal disease amenable to endovascular therapy. Patients were not eligible if there was no patent tibial artery, extensive PAD, or an arterial target in the foot for bypass.

RESULTS

Of 106 limbs reviewed, 35 (33%) did not undergo angiography ≤6 months before amputation because of infection (n=14), advanced tissue loss (n=10), failed revascularizations (n=8), advanced limb ischemia (n=2), and refusing revascularization (n=1). Thus, 69 lower extremity angiograms (2 incomplete excluded) in 68 patients were analyzed. 15 patients with 16 limbs (23.2%) were identified as candidates for pDVA (ideal=7, possible=9). There were no differences in demographics between the two groups, but candidates for pDVA were less likely to have hyperlipidemia and congestive heart failure than those who were not candidates. pDVA candidates underwent significantly fewer interventions prior to major amputation compared to patients who were not candidates (1.50 ± 0.73 vs 2.61 ± 2.57, p=0.007). Angiographically, patients who were pDVA candidates had significantly higher Inframalleolar GLASS grades (1.81 ± 0.40 vs 0.86 ± 0.41, p<0.0001) but lower Femoropopliteal Glass grades (0.73 ± 1.10 vs 2.43 ± 1.71, p<0.0001) than patients who were not candidates. There was no significant difference in GLASS stage between these two groups (p=0.368). After mean follow-up of 48 months, there was no difference in mortality between both groups (40% vs 32.1%, p=0.567).

CONCLUSION

Among patients considered for revascularization, 23.2% had favorable angiography and 14.7% could have benefited for pDVA as a new therapeutic modality for limb salvage. 33% of major amputations were performed for clinically-deemed unsalvageable CLTI.

A systematic review of patient-reported outcome measures patients with chronic limb-threatening ischemia

Chronic limb-threatening ischemia (CLTI) causes significant morbidity with profound negative effects on health-related quality of life. As the prevalence of peripheral artery disease and diabetes continue to rise in our aging population, the public health impact of CLTI has escalated. Patient-reported outcome measures (PROMs) have become common and important measures for clinical evaluation in both clinical care and research. PROMs are important for the measurement of clinical effectiveness and cost effectiveness and for shared decision-making on treatment options. However, the PROMs used to describe the experience of patients with CLTI are heterogeneous, incomplete, and lack specific applicability to the underlying disease processes and diverse populations. For example, certain PROMs exist for patients with extremity wounds, and other PROMs exist for patients with pain, and still others exist for patients with vascular disease. Despite this multiplicity of tools, no single PROM encompasses all of the components necessary to describe the experiences of patients with CLTI. This significant unmet need is evident from both published reports and contemporary large-scale clinical trials in the field. In this systematic review, we review the current use of PROMs for patients with CLTI in clinical practice and in research trials and highlight the gaps that need to be addressed to develop a unifying PROM instrument for CLTI.

Therapeutic Alternatives in Diabetic Foot Patients without an Option for Revascularization: A Narrative Review

Background: The healing of foot wounds in patients with diabetes mellitus is frequently complicated by critical limb threatening ischemia (neuro-ischemic diabetic foot syndrome, DFS). In this situation, imminent arterial revascularization is imperative in order to avoid amputation. However, in many patients this is no longer possible (“too late”, “too sick”, “no technical option”). Besides conservative treatment or major amputation, many alternative methods supposed to decrease pain, promote wound healing, and avoid amputations are employed. We performed a narrative review in order to stress their efficiency and evidence. Methods: The literature research for the 2014 revision of the German evidenced-based S3-PAD-guidelines was extended to 2020. Results: If revascularization is impossible, there is not enough evidence for gene- and stem-cell therapy, hyperbaric oxygen, sympathectomy, spinal cord stimulation, prostanoids etc. to be able to recommend them. Risk factor management is recommended for all CLTI patients. With appropriate wound care and strict offloading, conservative treatment may be an effective alternative. Timely amputation can accelerate mobilization and improve the quality of life. Conclusions: Alternative treatments said to decrease the amputation rate by improving arterial perfusion and wound healing in case revascularization is impossible and lack both efficiency and evidence. Conservative therapy can yield acceptable results, but early amputation may be a beneficial alternative. Patients unfit for revascularization or major amputation should receive palliative wound care and pain therapy. New treatment strategies for no-option CLTI are urgently needed.

Health Related Quality of Life Over Time After Revascularisation in Patients With Chronic Limb Threatening Ischaemia

OBJECTIVE

Chronic limb threatening ischaemia (CLTI) decreases life expectancy and impairs health related quality of life (HR-QOL). Revascularisation is needed to relieve ischaemia and salvage limbs. Although a major goal of CLTI treatment is maintaining QOL, little information is available about changes of HR-QOL over time after revascularisation. HR-QOL with survival after revascularisation for CLTI was assessed.

METHODS

The clinical database of the Surgical reconstruction versus Peripheral INtervention in pAtients with critical limb isCHemia (SPINACH), a prospective multicentre observational study, was analysed. Outcome measures were disease specific QOL per the Vascular Quality of Life (VascuQOL) questionnaire and the Short Form (SF) 36 evaluated generic QOL, which were assessed at baseline and three, 12, 24, and 36 months. The outcome measure was change of QOL from baseline. The minimally important difference (half a standard deviation from baseline) was used as the cut off point for improved, worsened, and unchanged QOL.

RESULTS

Overall QOL was improved in 61% of patients for the VascuQOL and approximately 40% for the SF-36 component summaries at three months. However, these proportion gradually decreased to 21% - 31% at three years. In contrast, the proportion of deceased patients gradually increased over the three year follow up. Multivariable analysis revealed that pre-operative non-ambulatory status was inversely associated with improved QOL for the three month VascuQOL and SF-36 mental component summary, and surgical reconstruction was positively associated with these measurements. Advanced age and renal failure were inversely associated with improved QOL for the SF-36 mental component summary and VascuQOL at one to three years.

CONCLUSION

Revascularisation improved QOL. However, patients with non-ambulatory status exhibited a negative association with improved QOL at three months, and advanced age and renal failure limited benefits one to three years after revascularisation. Accumulating QOL data will be essential for post-revascularisation QOL estimation. Pre-operative assessment, including estimated QOL, is important in shared decision making for patient oriented outcomes in the treatment of CLTI patients.

Quality of life, physical functioning, and psychosocial function among patients with achondroplasia: a targeted literature review

PURPOSE

Achondroplasia (ACH) is the most common form of skeletal dysplasia, resulting in disproportionate short stature and medical complications. We review the literature on physical functioning, psychosocial function, and quality of life (QoL) in ACH individuals compared to average stature individuals or other short stature conditions. Studies that assess the association between these outcomes and height, limb length/lengthening surgery in ACH patients are also summarized.

MATERIALS AND METHODS

PubMed/MEDLINE and Embase were searched through April 2021. Study inclusion criteria were: (1) quantitative design; (2) study population consisting solely/mainly of ACH patients; (3) reports of physical functioning, psychosocial functioning, and/or QoL. Included studies were summarized separately for pediatric and adult populations.

RESULTS

Of 1664 records identified, 23 primary studies (sample size 8-437 participants) were included. Multiple tools were used across studies, including the generic PedsQL and SF-36 and height-specific QoLISSY.

CONCLUSIONS

The literature demonstrates that ACH patients experience limitations in physical functioning and poorer QoL outcomes compared to average stature people across the life span. This appeared to be at least in part due to disproportionate short stature. Future research to better characterize QoL in ACH patients will assist clinicians to better evaluate the effectiveness of management programs including novel interventions.IMPLICATIONS FOR REHABILITATIONPatients with achondroplasia experience limitations in physical functioning and poorer quality of life throughout their life course when compared to average statured individuals.Psychosocial issues are also heightened in adults with achondroplasia compared to average statured peers but are observed less frequently in children and adolescents with achondroplasia.The overall impact that limb lengthening has on physical functioning and QoL remains unclear, although there is some evidence that greater height or upper limb length may lead to an improvement in these parameters.Rehabilitation professionals should regularly assess physical functioning, psychosocial wellbeing, and quality of life in individuals with achondroplasia using condition-specific tools.

Gene therapy for critical limb ischemia: Per aspera ad astra

Peripheral artery diseases remain a serious public health problem. Although there are many traditional methods for their treatment using conservative therapeutic techniques and surgery, gene therapy is an alternative and potentially more effective treatment option especially for "no option" patients. This review treats the results of many years of research and application of gene therapy as an example of treatment of patients with critical limb ischemia. Data on successful and unsuccessful attempts to use this technology for treating this disease are presented. Trends in changing the paradigm of approaches to therapeutic angiogenesis are noted: from viral vectors to non-viral vectors, from gene transfer to the whole organism to targeted transfer to cells and tissues, from single gene use to combination of genes; from DNA therapy to RNA therapy, from in vivo therapy to ex vivo therapy.

National Trends for Peripheral Artery Disease and End Stage Renal Disease From the National Inpatient Sample Database

Peripheral artery disease (PAD), and subsequent chronic limb-threatening ischemia (CLTI), are frequently encountered among patients with end-stage renal disease (ESRD). Their coexistence is less favorable in comparison to patients with ESRD alone. We sought to investigate trends, comorbidities, determinants for cost, and prognostic outcomes in patients with concomitant ESRD and PAD. A retrospective analysis was performed using data from the National Inpatient Sample database from the years 2005-2014. ICD-9 codes were used to identify patients with diagnoses of PAD, CLTI, and ESRD. Pearson’s Chi-square, T-test, ANOVA, and multivariate binary logistic regression were used in this analysis. 7,214,843 patients with ESRD were identified. Of these, 123,499 patients were diagnosed with PAD and 102,447 with CLTI. Compared to ESRD alone, mortality rates increased with PAD and CLTI (5.7% vs. 13.9% vs. 15.9%, P < 0.001). Length of stay in days (7.3 vs. 10.2 vs. 11.1, P < 0.001) and in-hospital costs (59,872 vs. 85,866 vs. 89,016, P < 0.001) were higher with PAD and CLTI, respectively. CLTI demonstrated the highest independent predictor of mortality [OR = 6.93 (6.43-7.46), P < 0.001]. A decreasing trend in the rate of PAD (2005: 1.9% vs. 2014: 1.4%, P < 0.001) and CLTI (2005: 1.6% vs. 2014: 1.1%, P < 0.001) was noted. The presence of coexisting PAD, and furthermore CLTI, in patients with ESRD significantly raised in-hospital mortality, cost, and length of stay. A negative trend in rates of PAD and CLTI were observed. Proactive identification of this high-risk population may lead to accurate diagnosis and tailored therapeutic strategies.

[Diabetic foot syndrome-Part 2 : Revascularization, treatment alternatives, care structures, recurrency prophylaxis]

Diabetic foot syndrome (DFS) is the most frequent reason for major amputations in Germany. The majority of foot lesions are triggered by repetitive pressure in diabetic polyneuropathy. Peripheral arterial occlusive disease (PAOD) impairs wound healing and is the main risk factor for amputations. The treatment of wounds and infections as well as timely revascularization are decisive. The use of endovascular and vascular surgical methods depends on the distribution pattern and length of the occlusion processes. Both procedures are complementary. Bypass surgery is of great importance for neuroischemic DFS. Multidisciplinary centers that provide revascularization in DFS can achieve an improvement of arterial blood flow in 90% of the cases and reduce the amputation rate by up to 80%. Due to the high recurrence rate of diabetic foot lesions, measures for secondary prophylaxis are of exceptional importance (podological and orthopedic technical care, foot surgery).

Stakeholder Values and Preferences in Lower Limb Amputation for No-Option Chronic Limb Threatening Ischemia

PURPOSE

This study focusses on identifying values and preferences of patients, caregivers and healthcare professionals who have dealt with lower limb amputation for no-option chronic limb threatening ischemia. No-option chronic limb threatening ischemia is defined as limb ischemia for which no treatment options exist and where lower limb amputation is necessary in the short term. The values and preferences identified in this study can help improve decision-making processes.

PATIENTS AND METHODS

This was a qualitative study, using semi-structured interviews to gather data from patients, caregivers and healthcare professionals. Participants were selected from the patient and employee population of an academic medical center in The Netherlands. Nine patients and seven caregivers who dealt with lower limb amputation for no-option chronic limb threatening ischemia six to twelve months prior to the interview and were not cognitively impaired were selected. Nine healthcare professionals dealing with patients with no-option chronic limb threatening ischemia and lower limb amputation were selected.

RESULTS

Lower limb amputation was explicitly discussed late in the disease process, sometimes during an emergency setting. Patients stated goals were never discussed, healthcare professionals stated they were. The most important goal for patients was to live independently after lower limb amputation. Patients and caregivers feel healthcare professionals should be upfront about the possible necessity of lower limb amputation. Reasons to undergo lower limb amputation were absence of treatment options, pain and wanting to enjoy life again. Participants indicated accelerating lower limb amputation was not a viable option.

CONCLUSION

All stakeholders reported overlapping values and preferences regarding main reasons for lower limb amputation, the primary goals after lower limb amputation, and the absence of a desire to accelerate lower limb amputation. The main difference in values and preferences is the preferred timing of discussing lower limb amputation.

Collateral artery bypass in the infrapopliteal segment

A 74-year-old man with diabetes and end-stage renal failure on regular dialysis required revascularization for gangrene of multiple toes and a heel ulcer on the right foot with chronic limb-threatening ischemia. However, the anterior tibial artery, posterior tibial artery, and peroneal artery, which are the usual targets below the knee, showed obstruction or calcification and were considered inappropriate bypass targets. Instead, a collateral artery developed along the area of the posterior tibial artery, and bypass surgery was performed with this artery. This is a case report showing successful collateral artery bypass grafting in the distal infrapopliteal segment.

Randomized, Double-Blind, Placebo-Controlled Trial to Evaluate Safety and Therapeutic Efficacy of Angiogenesis Induced by Intraarterial Autologous Bone Marrow-Derived Stem Cells in Patients with Severe Peripheral Arterial Disease

PURPOSE

To evaluate safety and efficacy of angiogenesis induced by intraarterial autologous bone marrow-derived stem cell (BMSC) injection in patients with severe peripheral arterial disease (PAD).

MATERIALS AND METHODS

Eighty-one patients with severe PAD (77 men), including 56 with critical limb ischemia (CLI) and 25 with severe claudication, were randomized to receive sham injection (group A) or intraarterial BMSC injection at the site of occlusion (group B). Primary endpoints included improvement in ankle-brachial index (ABI) of > 0.1 and transcutaneous pressure of oxygen (TcPO₂) of > 15% at mid- and lower foot at 6 mo. Secondary endpoints included relief from rest pain, > 30% reduction in ulcer size, and reduction in major amputation in patients with CLI and > 50% improvement in pain-free walking distance in patients with severe claudication.

RESULTS

Technical success was achieved in all patients, without complications. At 6 mo, group B showed more improvements in ABI of > 0.1 (35 of 41 [85.37%] vs 13 of 40 [32.50%]; P < .0001) and TcPO₂ of > 15% at the midfoot (35 of 41 [85.37%] vs 17 of 40 [42.50%]; P = .0001] and lower foot (37 of 41 [90.24%] vs 19 of 40 [47.50%]; P < .0001). No patients with CLI underwent major amputation in group B, compared with 4 in group A (P = .0390). No significant difference was observed in relief from rest pain or > 30% reduction in ulcer size among patients with CLI or in > 50% improvement in pain-free walking distance among patients with severe claudication.

CONCLUSIONS

Intraarterial delivery of autologous BMSCs is safe and effective in the management of severe PAD.

A Comparison of Quality of Life in Elderly Patients with Intermittent Claudication and Chronic Limb-Threatening Ischemia

BACKGROUND

Intermittent claudication (IC) and chronic limb-threatening ischemia (CLTI) are both associated with a decreased health status and possibly quality of life (QOL). A better understanding of the differences in QOL between patients with IC and CLTI could be of additional value in shared decision-making. The aim of this study was to compare the QOL at baseline between patients with IC and patients with CLTI.

METHODS

The study population was based on 2 study cohorts, 1 cohort consisted of patients with IC (ELECT registry) and the other cohort of patients with CLTI (KOP-study). Patients with an age of ≥70 years were included. QOL at baseline was measured by the WHOQOL-BREF questionnaire. Nonresponders were excluded from data analyses. Student's t-tests and analysis of covariance (ANCOVA) analyses were used to compare QOL between the 2 groups. Outcomes of the ANCOVA analyses were expressed as estimated marginal means.

RESULTS

In total, 308 patients were included, 115 patients with IC and 193 patients with CLTI. Patients with CLTI were older (median age 80 years vs. 75 years, P < 0.001) and had more comorbidities. Patients with IC had a statistically significant higher QOL regarding physical health (mean 13.7 [standard deviation (SD) 2.3] vs. 10.8 [SD 2.8], P < 0.001), psychological health (mean 15.3 [SD 2.1] vs. 14.1 [SD 2.4], P < 0.001), environment (mean 16.3 [SD 2.4] vs. 15.5 [SD 2.0], P < 0.002), and the overall domain (mean 3.5 [SD 0.7] vs. 3.1 [SD 0.9], P < 0.001). After correcting for the confounding effect of age and sex, patients with IC still had a statistically significant higher QOL in the physical, psychological, environment, and overall domain.

CONCLUSIONS

Patients with IC had a significantly higher QOL in the physical, psychological, environment, and overall domains of the WHOQOL-BREF questionnaire compared with patients with CLTI. This underlines the importance of strategies that reduce disease progression as disease progression is associated with a decrease in QOL.

New Innovations and Devices in the Management of Chronic Limb-Threatening Ischemia

As the number of patients afflicted by chronic limb-threatening ischemia (CLTI) continues to grow, new solutions are necessary to provide effective, durable treatment options that will lead to improved outcomes. The diagnosis of CLTI remains mostly clinical, and endovascular revascularization remains mostly balloon-based. Multiple innovative techniques and technologies are in development or in early usage that may provide new solutions. This review categorizes areas of advancement, highlights recent developments in the management of CLTI and looks forward to novel devices that are currently under investigation.

Arterial Reconstruction for Patients with Chronic Limb Ischemia Improves Ambulatory Function and Health-related Quality of Life

BACKGROUND

Arterial reconstruction (AR) for limb ischemia may improve ambulatory function (AF) and health-related quality of life (HR-QoL). However, the efficacy of AR in terms of HR-QoL varies in studies, probably because of cohort differences in disease severity, hemodynamic outcomes, and observation duration. We assessed HR-QoL for patients with various severities of ischemia in a 3-year observational study.

METHODS

We conducted a single-center 3-year observational study using Short Form 36 in patients with chronic limb ischemia. Between 2001 and 2009, 515 consecutive patients had AR, and 330 who underwent elective AR consented to the study. Of the 330 patients (claudicants 49%, critical limb ischemia [CLI] 51%), 307 underwent bypass and 23 endovascular therapy. Postal questionnaires were sent after AR, and 8 domains, the physical and mental component summary (PCS and MCS) scores, and the patient-reported AF were compared, and negative predictors were identified.

RESULTS

Overall, the MCS was minimally affected, but AF and the PCS were impaired. After AR, these measures were significantly improved, and maximum recovery was attained at 6 months. In subgroup analysis, significant predictors of a negative impact on postoperative PCS included age ≥80, CLI, physical aftereffects of stroke (PAS), and previous major amputation (PMA). Of these, PMA was associated with the lowest PCS score, followed by PAS; for these patients, AR contributed minimally to HR-QoL recovery. PCS scores of claudicants attained a maximum value at 6 months; however, PCS scores of CLI patients were significantly lower than intermittent claudication patients (P < 0.0001), and patients with major tissue loss required 2 years to attain maximum PCS recovery.

CONCLUSIONS

This 3-year observational study verified the efficacy of AR in improving AF and HR-QoL. Age ≥80, CLI, PAS, and PMA were definitive predictors, and for patients with the latter 2, AR contributed minimally to improving HR-QoL.

PROMISE international; a clinical post marketing trial investigating the percutaneous deep vein arterialization (LimFlow) in the treatment of no-option chronic limb ischemia patient

BACKGROUND

Critical limb ischemia (CLI) is the clinical end stage of peripheral artery disease and is associated with high amputation, mortality rates and poor quality of life. For CLI patients with no revascularization options, venous arterialization could be an alternative technique for limb salvage. A systematic review and meta-analysis published in 2017 concluded that venous arterialization may be considered a viable alternative. A recent development, is the Percutaneous Deep Vein Arterialization (pDVA), that is CE-marked and currently under investigation of the FDA. This procedure, called LimFlow, is a novel, minimally invasive, endovascular approach to perform a venous arterialization procedure. The limited evidence for its use necessitates a scientific judgement of the pDVA. Therefore, we initiated a prospective clinical post market trial to investigate the outcome of the pDVA in no-option critical limb ischemia.

METHODS/DESIGN

The objective of this prospective study is to collect "real-life" clinical data among a population of patients treated with the pDVA in order to evaluate the clinical effectiveness and safety of the LimFlow System in patients with no-option critical limb ischemia. This study is a single-arm, open-label, prospective, post-market follow-up study to be conducted on up to fifty (50) eligible patients with a twelve-month follow-up period. The Primary endpoint is measured by amputation free survival. Secondary endpoints are complete wound healing, primary and secondary patency, limb salvage, renal function and technical and procedural success. Patients will be assessed at regular intervals during one year after the initial percutaneous deep vein arterialization procedure through clinical evaluation and self-completed questionnaires.

DISCUSSION

The last decade several studies have been published with promising results and the number of treated patients has considerably grown. Venous arterialization could be a valuable treatment option in patients with often no other options than amputation of the affected limb. The first results in men are promising although more research and long term follow up is needed to establish the efficacy of this new treatment modality. With this prospective study, we evaluate the clinical effectiveness and safety in patients with no-option CLI treated with the pDVA (LimFlow System).

TRIAL REGISTRATION

NCT03321552 .

[The effect of spinal card stimulation on quality of life in patients with critical lower limb ischemia]

Today, there are insufficient data on the dynamics of quality of life (QoL) in patients with critical lower limb ischemia after spinal cord stimulation.

OBJECTIVE

To study the dynamics of QoL in patients with critical lower limb ischemia one year after spinal cord stimulation.

MATERIAL AND METHODS

QoL analysis was performed in 43 patients with critical lower limb ischemia using the SF-36 questionnaire before and one year after spinal cord stimulation.

RESULTS

At baseline, we detected reduced QoL parameters corresponding to the physical function (≤30 points). The parameters of mental health corresponded to the moderate level (the score ranged between 42 and 59 points). The total score of physical well-being was reduced: 22.8 (20.2-29.3); the mean score of mental well-being was 41 (32.8-49.2) (p<0.001). One year after spinal cord stimulation, the level of all QoL parameters was increased but the total score of physical well-being remained low 33.2 (24-44.1). The mean score of mental well-being corresponded to the moderate level of QoL 56.5 (49-60.4) (p<0.001). Multivariate regression analysis showed that the physical parameters of QoL after spinal cord stimulation are adversely affected by such factors as age, the history of stroke, the ankle-brachial index (ABI), the presence of type 2 diabetes mellitus (DM), and ischemic heart disease (IHD) in combination with stenosis of brachiocephalic arteries (BCA). The mental health is affected by age and the presence of stenosis of brachiocephalic arteries.

CONCLUSION

When selecting patients with critical lower limb ischemia for spinal cord stimulation, such factors as the baseline clinical status (comorbidities), age, history of stroke, and the severity of peripheral artery ischemia need to be taken into account to improve treatment effectiveness and QoL.

Peripheral artery disease: the new frontiers of imaging techniques to evaluate the evolution of regenerative medicine

Introduction: Stem cells (ESC, iPSC, MSC) are known to have intrinsic regenerative properties. In the last decades numerous findings have favored the development of innovative therapeutic protocols based on the use of stem cells (Regenerative Medicine/Cell Therapy) for the treatment of numerous diseases including PAD, with promising results in preclinical studies. So far, several clinical studies have shown a general improvement of the patient's clinical outcome, however they possess many critical issues caused by the non-randomized design of the limited number of patients examined, the type cells to be used, their dosage, the short duration of treatment and also their delivery strategy. Areas covered: In this context, the use of the most advanced molecular imaging techniques will allow the visualization of very important physio-pathological processes otherwise invisible with conventional techniques, such as angiogenesis, also providing important structural and functional data. Expert opinion: The new frontier of cell therapy applied to PAD, potentially able to stop or even the process that causes the disease, with particular emphasis on the clinical aspects that different types of cells involve and on the use of more innovative molecular imaging techniques now available.

The burden of critical limb ischemia: a review of recent literature

Peripheral arterial disease is a chronic vascular disease characterized by impaired circulation to the lower extremities. Its most severe stage, known as critical limb ischemia (CLI), puts patients at an increased risk of cardiovascular events, amputation, and death. The objective of this literature review is to describe the burden of disease across a comprehensive set of domains—epidemiologic, clinical, humanistic, and economic—focusing on key studies published in the last decade. CLI prevalence in the United States is estimated to be approximately 2 million and is likely to rise in the coming years given trends in important risk factors such as age, diabetes, and smoking. Hospitalization for CLI patients is common and up to 60% are readmitted within 6 months. Amputation rates are unacceptably high with a disproportionate risk for certain demographic and socioeconomic groups. In addition to limb loss, CLI patients also have reduced life expectancy with mortality typically exceeding 50% by 5 years. Given the poor clinical prognosis, it is unsurprising that the quality of life burden associated with CLI is significant. Studies assessing quality of life in CLI patients have used a variety of generic and disease-specific measures and all document a substantial impact of the disease on the patient’s physical, social, and emotional health status compared to population norms. Finally, the poor clinical outcomes and increased medical resource use lead to a considerable economic burden for national health care systems. However, published cost studies are not comprehensive and, therefore, likely underestimate the true economic impact of CLI. Our summary documents a sobering assessment of CLI burden—a poor clinical prognosis translating into diminished quality of life and high costs for millions of patients. Continued prevention efforts and improved treatment strategies are the key to ameliorating the substantial morbidity and mortality associated with this disease.

Applications of Ultrasound to Stimulate Therapeutic Revascularization

Many pathological conditions are characterized or caused by the presence of an insufficient or aberrant local vasculature. Thus, therapeutic approaches aimed at modulating the caliber and/or density of the vasculature by controlling angiogenesis and arteriogenesis have been under development for many years. As our understanding of the underlying cellular and molecular mechanisms of these vascular growth processes continues to grow, so too do the available targets for therapeutic intervention. Nonetheless, the tools needed to implement such therapies have often had inherent weaknesses (i.e., invasiveness, expense, poor targeting, and control) that preclude successful outcomes. Approximately 20 years ago, the potential for using ultrasound as a new tool for therapeutically manipulating angiogenesis and arteriogenesis began to emerge. Indeed, the ability of ultrasound, especially when used in combination with contrast agent microbubbles, to mechanically manipulate the microvasculature has opened several doors for exploration. In turn, multiple studies on the influence of ultrasound-mediated bioeffects on vascular growth and the use of ultrasound for the targeted stimulation of blood vessel growth via drug and gene delivery have been performed and published over the years. In this review article, we first discuss the basic principles of therapeutic ultrasound for stimulating angiogenesis and arteriogenesis. We then follow this with a comprehensive cataloging of studies that have used ultrasound for stimulating revascularization to date. Finally, we offer a brief perspective on the future of such approaches, in the context of both further research development and possible clinical translation.

Review of the Current Basic Science Strategies to Treat Critical Limb Ischemia

Critical limb ischemia (CLI) is a highly morbid disease with many patients considered poor surgical candidates. The lack of treatment options for CLI has driven interest in developing molecular therapies within recent years. Through these translational medicine studies in CLI, much has been learned about the pathophysiology of the disease. Here, we present an overview of the macrovascular and microvascular changes that lead to the development of CLI, including impairment of angiogenesis, vasculogenesis, and arteriogenesis. We summarize the randomized clinical controlled trials that have used molecular therapies in CLI, and discuss the novel imaging modalities being developed to assess the efficacy of these therapies.

Six-Month Freedom From Amputation Rates and Quality of Life Following Tibial and Pedal Endovascular Revascularization for Critical Limb Ischemia

Objective:

Patients with critical limb ischemia (CLI) and gangrene have a 10% to 38% rate of major amputation at 6 months. The purpose of this study is to report short- and mid-term major and minor amputation rates for patients who underwent tibial and pedal revascularization in addition to quality-of-life (QoL) scores.

Methods:

All patients who presented to a single institution with CLI (defined as rest pain or nonhealing wounds) and underwent antegrade or retrograde tibial access, atherectomy and angioplasty of the tibial circulation, and angioplasty of pedal circulation (antegrade or retrograde) from June 2016 to September 2017 were included. The Stark QoL questionnaire was used at each visit. Patients were scored at 1, 3, and 6 months postprocedure. Amputation rates were recorded.

Results:

Forty-two patients with CLI and gangrene underwent 57 peripheral interventions for limb salvage between June 2016 and September 2017. Thirty-two limbs had dry gangrene along the dorsalis pedis angiosome, 14 limbs had dry gangrene along the posterior tibial angiogram, and 11 limbs had a combined disease pattern. Twelve limbs underwent angioplasty of the superficial femoral artery (SFA), 18 limbs underwent angioplasty and stenting of the SFA, and 14 limbs underwent atherectomy, angioplasty, and stenting of the SFA. All patients had 1 or 2 tibial vessel runoff and high-grade stenosis of the pedal circulation. Immediate technical success defined as 3-vessel outflow to the foot occurred in 49 limbs (86%) with zero 30-day complications (30-day readmission, major amputation, or sepsis). Major amputation rate at 1, 3, and 6 months was 0%, 2%, and 4%, respectively. Patient satisfaction in terms of QoL increased over the 6-month follow-up period.

Conclusion:

Aggressive tibial and pedal revascularization may improve freedom from minor and major amputation at 6 months and may be associated with a short- and mid-term higher QoL.

Systematic review of pharmacological therapies for the management of ischaemic pain in patients with non-reconstructable critical limb ischaemia

BACKGROUND

Critical limb ischaemia (CLI) is a severe manifestation of peripheral arterial disease, characterised by chronic ischaemic rest pain, ulcers or gangrene. Management of ischaemic pain is challenging in patients with no options for revascularisation and optimal pharmacological therapies have not been established.

OBJECTIVES

To identify and evaluate the effectiveness of pharmacological therapies to treat ischaemic pain secondary to non-reconstructable CLI.

METHODS

This systematic review was reported in accordance with PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guideline. Comprehensive searches of three electronic databases, a PubMed-related articles link search, grey literature search and hand-searches of the bibliographies of relevant papers and textbooks were performed. Studies recruiting adult patients with CLI of any aetiology were eligible for inclusion. Surgical and revascularisation procedures, and all invasive interventions were excluded.

RESULTS

Of 792 studies, six met full inclusion criteria. These studies researched the use of intravenous lidocaine, intravenous ketamine, oral gabapentin and the combination of transdermal buprenorphine and epidural morphine/ropivacaine infusion. All studies showed an improvement in severity of ischaemic pain in CLI but with varying side effect profiles and quality. The extracted studies showed substantial heterogeneity and therefore a meta-analysis was not performed.

CONCLUSION

The pharmacological management of pain secondary to non-reconstructable CLI is a challenging review topic. No recommendations of pharmacological agents can be made following this review but a number of novel approaches to manage pain in this cohort have shown positive results and require further investigation.

Autologous Stem Cell Therapy in Critical Limb Ischemia: A Meta-Analysis of Randomized Controlled Trials

Objective

Critical limb ischemia (CLI) is the most dangerous stage of peripheral artery disease (PAD). Many basic researches and clinical treatment had been focused on stem cell transplantation for CLI. This systematic review was performed to review evidence for safety and efficacy of autologous stem cell therapy in CLI.

Methods

A systematic literature search was performed in the SinoMed, PubMed, Embase, ClinicalTrials.gov, and Cochrane Controlled Trials Register databases from building database to January 2018.

Results

Meta-analysis showed that cell therapy significantly increased the probability of ulcer healing (RR = 1.73, 95% CI = 1.45–2.06), angiogenesis (RR = 5.91, 95% CI = 2.49–14.02), and reduced the amputation rates (RR = 0.59, 95% CI = 0.46–0.76). Ankle-brachial index (ABI) (MD = 0.13, 95% CI = 0.11–0.15), TcO₂ (MD = 12.22, 95% CI = 5.03–19.41), and pain-free walking distance (MD = 144.84, 95% CI = 53.03–236.66) were significantly better in the cell therapy group than in the control group (P < 0.01).

Conclusions

The results of this meta-analysis indicate that autologous stem cell therapy is safe and effective in CLI. However, higher quality and larger RCTs are required for further investigation to support clinical application of stem cell transplantation.

Prostanoids for critical limb ischaemia

BACKGROUND

Peripheral arterial occlusive disease (PAOD) is a common cause of morbidity and mortality due to cardiovascular disease in the general population. Although numerous treatments have been adopted for patients at different disease stages, no option other than amputation is available for patients presenting with critical limb ischaemia (CLI) unsuitable for rescue or reconstructive intervention. In this regard, prostanoids have been proposed as a therapeutic alternative, with the aim of increasing blood supply to the limb with occluded arteries through their vasodilatory, antithrombotic, and anti-inflammatory effects. This is an update of a review first published in 2010.

OBJECTIVES

To determine the effectiveness and safety of prostanoids in patients with CLI unsuitable for rescue or reconstructive intervention.

SEARCH METHODS

For this update, the Cochrane Vascular Information Specialist searched the Specialised Register (January 2017) and the Cochrane Central Register of Controlled Trials (CENTRAL; 2017, Issue 1). In addition, we searched trials registries (January 2017) and contacted pharmaceutical manufacturers, in our efforts to identify unpublished data and ongoing trials.

SELECTION CRITERIA

Randomised controlled trials describing the efficacy and safety of prostanoids compared with placebo or other pharmacological control treatments for patients presenting with CLI without chance of rescue or reconstructive intervention.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials, assessed trials for eligibility and methodological quality, and extracted data. We resolved disagreements by consensus or by consultation with a third review author.

MAIN RESULTS

For this update, 15 additional studies fulfilled selection criteria. We included in this review 33 randomised controlled trials with 4477 participants; 21 compared different prostanoids versus placebo, seven compared prostanoids versus other agents, and five conducted head-to-head comparisons using two different prostanoids.We found low-quality evidence that suggests no clear difference in the incidence of cardiovascular mortality between patients receiving prostanoids and those given placebo (risk ratio (RR) 0.81, 95% confidence interval (CI) 0.41 to 1.58). We found high-quality evidence showing that prostanoids have no effect on the incidence of total amputations when compared with placebo (RR 0.97, 95% CI 0.86 to 1.09). Adverse events were more frequent with prostanoids than with placebo (RR 2.11, 95% CI 1.79 to 2.50; moderate-quality evidence). The most commonly reported adverse events were headache, nausea, vomiting, diarrhoea, flushing, and hypotension. We found moderate-quality evidence showing that prostanoids reduced rest-pain (RR 1.30, 95% CI 1.06 to 1.59) and promoted ulcer healing (RR 1.24, 95% CI 1.04 to 1.48) when compared with placebo, although these small beneficial effects were diluted when we performed a sensitivity analysis that excluded studies at high risk of bias. Additionally, we found evidence of low to very low quality suggesting the effects of prostanoids versus other active agents or versus other prostanoids because studies conducting these comparisons were few and we judged them to be at high risk of bias. None of the included studies assessed quality of life.

AUTHORS' CONCLUSIONS

We found high-quality evidence showing that prostanoids have no effect on the incidence of total amputations when compared against placebo. Moderate-quality evidence showed small beneficial effects of prostanoids for rest-pain relief and ulcer healing when compared with placebo. Additionally, moderate-quality evidence showed a greater incidence of adverse effects with the use of prostanoids, and low-quality evidence suggests that prostanoids have no effect on cardiovascular mortality when compared with placebo. None of the included studies reported quality of life measurements. The balance between benefits and harms associated with use of prostanoids in patients with critical limb ischaemia with no chance of reconstructive intervention is uncertain; therefore careful assessment of therapeutic alternatives should be considered. Main reasons for downgrading the quality of evidence were high risk of attrition bias and imprecision of effect estimates.

Rationale and design of the SAIL trial for intramuscular injection of allogeneic mesenchymal stromal cells in no-option critical limb ischemia

BACKGROUND

Critical limb ischemia (CLI) represents the most severe form of peripheral artery disease and has an immense impact on quality of life, morbidity, and mortality. A considerable proportion of CLI patients are ineligible for revascularization, leaving amputation as the only option. Mesenchymal stromal cells (MSCs), because of their vasculoregenerative and immunomodulatory characteristics, have emerged as a potential new treatment.

METHODS

The primary objective of this trial is to investigate whether intramuscular administration of allogeneic bone marrow (BM)-derived MSCs is safe and potentially effective. The SAIL (allogeneic mesenchymal Stromal cells for Angiogenesis and neovascularization in no-option Ischemic Limbs) trial is a double-blind, placebo-controlled randomized clinical trial to investigate the effect of allogeneic BM-MSCs in patients with CLI who are not eligible for conventional revascularization. A total of 66 patients will be included and randomized (1:1) to undergo 30 intramuscular injections with either BM-MSCs (5 × 10⁶ MSCs per injection) or placebo in the ischemic lower extremity. Primary outcome, that is, therapy success, a composite outcome consisting of mortality, limb status, clinical status, and changes in pain score, will be assessed at 6 months. All study-related procedures will take place in the University Medical Center Utrecht in The Netherlands.

CONCLUSIONS

If our results indicate that intramuscular allogeneic BM-MSC therapy for CLI is safe and potentially effective, this will have important consequences for treatment of patients with CLI. A large multicenter clinical trial with longer follow-up focusing on hard end points should then be initiated to confirm these findings.

Rationale and design of the MarrowStim PAD Kit for the Treatment of Critical Limb Ischemia in Subjects with Severe Peripheral Arterial Disease (MOBILE) trial investigating autologous bone marrow cell therapy for critical limb ischemia

OBJECTIVE

Critical limb ischemia (CLI) continues to place a significant encumbrance on patients and the health care system as it progresses to limb loss and long-term disability. Traditional methods of revascularization offer a significant benefit; however, for one-third of CLI patients, these surgical options are not technically possible or patency is severely limited by disease burden (deemed "poor-option" for revascularization). In a previous phase I trial, we demonstrated intramuscular injection of concentrated bone marrow aspirate (cBMA) via MarrowStim (Zimmer Biomet, Warsaw, Ind) harvest is safe and may decrease major amputation in patients with CLI unfit for surgical revascularization. Therefore, we describe and rationalize the MarrowStim PAD Kit for the Treatment of Critical Limb Ischemia in Subjects with Severe Peripheral Arterial Disease (MOBILE) trial, a study geared to provide the pivotal proof of efficacy of cBMA in CLI.

METHODS

MOBILE is a multicenter, randomized, double-blind, placebo-controlled trial designed to assess the efficacy of intramuscular injections of cBMA in promoting amputation-free survival in patients with poor-option CLI. Patients (aged >21 years) with rest pain or tissue loss resulting from advanced peripheral arterial disease, as characterized by ankle-brachial index (<0.6), toe-brachial index (<0.4), or transcutaneous pressure of oxygen (<50 mm Hg), were eligible for inclusion if surgical revascularization was not possible secondary to advanced disease.

RESULTS

Treatment and 1-year follow-up of 152 patients enrolled in MOBILE are completed. Long-term follow-up is ongoing. Currently, we are in the process of unblinding the initial results for preliminary data analysis.

CONCLUSIONS

If successful, MOBILE could add definitive, high-quality evidence in support of cBMA for the treatment of poor-option CLI patients and provide an additional modality for patients who face amputation secondary to advanced limb ischemia.

Venous Arterialisation for Salvage of Critically Ischaemic Limbs: A Systematic Review and Meta-Analysis

BACKGROUND

Critical limb ischaemia (CLI) is the end stage of peripheral artery disease (PAD) and is associated with high amputation and mortality rates and poor quality of life. For CLI patients with no revascularisation options, venous arterialisation could be a last resort for limb salvage.

OBJECTIVE

To review the literature on the clinical effectiveness of venous arterialisation for lower limb salvage in CLI patients with no revascularisation options.

METHOD

Different databases were searched for papers published between January 1966 and January 2016. The criteria for eligible articles were studies describing outcomes of venous arterialisation, published in English, human studies, and with the full text available. Additionally, studies were excluded if they did not report limb salvage, wound healing or amputation as outcome measures. The primary outcome measure was post-operative limb salvage at 12 months. Secondary outcome measures were 30 day or in-hospital mortality, survival, patency, technical success, and wound healing.

RESULTS

Fifteen articles met the inclusion criteria. The included studies described 768 patients. According to the MINORS score, methodological quality was moderate to poor. The estimated pooled limb salvage rate at one year was 75% (0.75, 95% CI 0.70-0.81). Thirty day or in-hospital mortality was reported in 12 studies and ranged from 0 to 10%. Overall survival was reported in 10 studies and ranged from 54% to 100% with a mean follow-up ranging from 5 to 60 months. Six studies reported on patency of the venous arterialisations performed, with a range of 59-71% at 12 months.

CONCLUSION

In this systematic review on venous arterialisation in patients with non-reconstructable critical limb ischaemia, the pooled proportion of limb salvage at 12 months was 75%. Venous arterialisation could be a valuable treatment option in patients facing amputation of the affected limb; however, the current evidence is of low quality.

Quality-of-life assessment as an outcomes measure in critical limb ischemia

Critical limb ischemia (CLI) is a diagnosis plagued by significant comorbidity and high mortality rates. Overall survival remains poor in this population regardless of the procedure-related success as demonstrated by freedom from amputation, intervention, and patency. The literature has traditionally focused on physician-centered and lesion-centered outcomes with regards to limb salvage procedures, but there remains a relative paucity of studies of CLI patients describing patient-centered outcomes such as quality of life (QoL), independent living, and ambulation status. Review of the available literature indicates patients do not always experience significant gains in their QoL after limb salvage interventions, despite reasonable graft patency, amputation-free survival, and limb salvage rates. Further research is required using QoL tools in a measurable and clinically relevant fashion to guide optimal quality care that maximizes patient-centered outcomes.

Peripheral artery disease: epidemiology and global perspectives

Global populations are undergoing a major epidemiological transition in which the burden of atherosclerotic cardiovascular diseases is shifting rapidly from high-income to low-income and middle-income countries (LMICs). Peripheral artery disease (PAD) is no exception, so that greater focus is now required on the prevention and management of this disease in less-advantaged countries. In this Review, we examine the epidemiology of PAD and, where feasible, take a global perspective. However, the dearth of publications in LMICs means an unavoidable over-reliance on studies in high-income countries. Research to date suggests that PAD might affect a greater proportion of women than men in LMICs. Although factors such as poverty, industrialization, and infection might conceivably influence the development of PAD in such settings, the ageing of the population and increase in traditional cardiovascular risk factors, such as smoking, diabetes mellitus, and hypertension, are likely to be the main driving forces.

Improved quality of life in patients with no-option critical limb ischemia undergoing gene therapy with DVC1-0101

Critical limb ischemia (CLI) has a poor prognosis and adversely affects patients' quality of life (QOL). Therapeutic angiogenesis may improve mobility, mortality, and QOL in CLI patients. However, the effectiveness of gene therapy on such patients' QOL is unknown. DVC1-0101, a non-transmissible recombinant Sendai virus vector expressing human fibroblast growth factor-2 gene, demonstrated safety and efficacy in a phase I/II study of CLI patients. We investigated the effects of DVC1-0101 on QOL in this cohort. QOL was assessed using the Short Form-36 health survey version 2 (SF-36) in 12 patients at pre-administration, 28 days, and 3, 6, and 12 months post-treatment. We examined differences between pre and post-administration QOL scores and correlations between QOL scores and vascular parameters. Patients demonstrated low baselines scores on every SF-36 dimension. Post-treatment scores showed significant improvements in physical functioning at 3 and 6 months (P < 0.05), role-physical at 3, 6, and 12 months (P < 0.05), bodily pain at 1, 3, 6, and 12 months (P < 0.05), vitality at 1, 6, and 12 months (P < 0.05), and physical component summary at 6 and 12 months (P < 0.05). DVC1-0101-based gene therapy may improve QOL in CLI patients over a 6-month period.

Autologous bone marrow mononuclear cell therapy for critical limb ischemia is effective and durable

OBJECTIVE

We have previously shown that autologous bone marrow mononuclear cell (ABMNC) therapy improves measures of limb perfusion, rest pain, wound healing, and amputation-free survival (AFS) at 1 year in patients with critical limb ischemia (CLI). Long-term durability of ABMNC therapy for CLI remains unknown. The objective of the current study was to evaluate long-term clinical outcomes 5 years after treatment.

METHODS

Data were retrospectively gathered from a database and via a patient survey and review of medical records of patients previously enrolled in this phase I/II trial. AFS, freedom from major amputation, and freedom from major adverse limb events (MALE) were calculated using the product-limit estimate. The incidence of cardiac, malignant, and other medical events relevant to the safety of cell therapy were tabulated during the time from treatment to follow-up.

RESULTS

Twenty-one of the 24 patients (88%) who completed the initial 1-year phase I/II trial were available for the 5-year analysis; AFS was 74% (95% confidence interval [CI], 0.53-0.87), freedom from major amputation was 78% (95% CI, 0.58-0.90), and freedom from MALE was 65% (95% CI, 0.45-0.80). Three patients (14%) had major cardiac events. There were no incidences of malignancies or diagnoses of clinically significant proliferative retinopathy. Fifteen patients (71%) report continued improvement in pain-free walking. Nineteen (90%) patients believed that the study was of significant medical value and would participate again.

CONCLUSIONS

ABMNC therapy provides long-term freedom from AFS, major amputation, and MALE that are comparable with other reports of patients who underwent surgical and endovascular interventions for CLI. Furthermore, no patients developed tumorigenesis or clinically significant retinopathy. Because of the limited number of patients studied, our findings will need to be followed up in a larger phase III trial.