Endovascular Treatment Of Critical Limb Ischemia Research Articles

Ultrasound-Guided Popliteal Sciatic Nerve Block: A Minimally Invasive Method for Pain Control During Endovascular Treatment of Critical Limb Ischemia

PurposeTo evaluate the safety and effectiveness of ultrasound-guided popliteal sciatic nerve block (PSNB) for pain control in endovascular treatment of critical limb ischemia (CLI). Materials and MethodsThis retrospective study included 252 patients who underwent endovascular treatment for CLI between January 2020 and August 2022. Of these, 69 patients underwent PSNB, whereas moderate procedural sedation and analgesia was delivered in 183 patients. Pain scores were assessed using the visual analog scale (VAS) before and during the intervention. Technical and clinical success of PSNB, duration of the procedure, time to onset of nerve block, time for block resolution, and adverse events were recorded. Patient and operator satisfaction were assessed using the Likert scale. ResultsAll PSNB procedures were technically and clinically successful, and the mean procedural duration of PSNB was 5.0 minutes ± 0.8 (range, 4–7 minutes). Prolonged effect of PSNB was observed in 3 patients, which resolved within 24 hours. No adverse events were encountered. Median VAS score was significantly lower in the PSNB group than in the moderate procedural sedation and analgesia group during endovascular treatment (0 [range, 0–2] vs 3 [range, 0–7]; P < .001). Patient satisfaction was comparable (“very satisfied” in 66 [95.7%] vs 161 [88.0%]; P = .069). However, operator satisfaction was significantly higher in the PSNB group (“very satisfied” in 69 [100%] vs 161 [88.0%]; P = .003). ConclusionsPSNB is safe and effective for pain control during endovascular treatment of CLI. Low adverse event rates with high patient and operator satisfaction make PSNB a reasonable alternative for high-risk patients.

Retrograde Pedal Access via Occluded Arteries in Endovascular Treatment of Critical Limb Ischemia

PurposeTo evaluate the feasibility and technical outcomes of retrograde access via occluded pedal arteries in endovascular treatment of critical limb ischemia (CLI) when the conventional antegrade approach fails. Materials and MethodsOne hundred fifty-one patients with CLI (age 69 y ± 10.5; 116 men) who were not surgical candidates and were treated via retrograde pedal access between January 2016 and January 2018 were evaluated retrospectively. Seventy patients in whom retrograde access was performed through occluded arteries constituted the occluded group, and 81 patients who were treated via retrograde access from patent arteries constituted the nonoccluded group. Pedal access success, lesion crossing success, angiographic success, overall technical success, and procedure-related complications were evaluated and compared between groups. ResultsPedal access success (74 of 78 vs 83 of 87 attempts; P = .873) and lesion crossing success (64 of 78 vs 77 of 87 lesions; P = .340) were comparable between subgroups. Angiographic success (54 of 78 vs 77 of 87 lesions; P = .012) and overall technical success (48 of 70 vs 72 of 81 patients; P = .004) rates were lower in the occluded group. Procedure-related complications were similar between groups (P = .096). ConclusionsRetrograde pedal access from occluded pedal arteries is a feasible option when an antegrade approach fails in endovascular treatment of CLI. Although it has lower technical success, its use enables angiosome-directed therapy and has the potential to improve the outcomes of the procedure.

2D perfusion DSA with an open-source, semi-automated, color-coded software for the quantification of foot perfusion following infrapopliteal angioplasty: a feasibility study

BackgroundFoot perfusion has been recently implemented as a new tool for optimizing outcomes of peripheral endovascular procedures. A custom-made, two-dimensional perfusion digital subtraction angiography (PDSA) algorithm has been implemented to quantify outcomes of endovascular treatment of critical limb ischemia (CLI), assist intra-procedural decision-making, and enhance clinical outcomes.MethodsThe study was approved by the Hospital’s Ethics Committee. This prospective, single-center study included seven consecutive patients scheduled to undergo infrapopliteal endovascular treatment of CLI. Perfusion blood volume (PBV), mean transit time (MTT), and perfusion blood flow (PBF) maps were extracted by analyzing time-intensity curves and signal intensity on the perfused vessel mask. Mean values calculated from user-specified regions of interest (ROIs) on perfusion maps were employed to evaluate pre- and post-endovascular treatment condition. Measurements were performed immediately after final PDSA.ResultsIn total, five patients (aged 54 ± 16 years, mean ± standard deviation) were analyzed, as two patients were excluded due to significant motion artifacts. Post-procedural MTT presented a mean decrease of 19.1% for all patients and increased only in 1 of 5 patients, demonstrating in 4/5 patients an increase in tissue perfusion after revascularization. Overall mean PBF and PBV values were also analogously increased following revascularization (446% and 69.5% mean, respectively) and in the majority of selected ROIs (13/15 and 12/15 ROIs, respectively).ConclusionsQuantification of infrapopliteal angioplasty outcomes using this newly proposed, custom-made, intra-procedural PDSA algorithm was performed using PBV, MTT, and PBF maps. Further studies are required to determine its role in peripheral endovascular procedures (ClinicalTrials.gov Identifier: NCT04356092).

Ultrasound Surveillance after Endovascular Therapy in Critical Limb Ischemia has Better Results Than Clinical and Haemodynamic Assesment Alone

Introduction - Endovascular treatment (EVT) has replaced open repair as first option in critical limb ischemia (CLI) during last years in the majority of centres. However, evidence in its surveillance is sparse, and has not yet been established. The aim of this study was to evaluate duplex ultrasound (DUS) surveillance after EVT for CLI, and compare it with clinical and haemodynamic assessment (CHA) alone.

A Review of Antithrombotic Treatment in Critical Limb Ischemia After Endovascular Intervention.

Endovascular intervention is often used to treat critical limb ischemia (CLI). Post-intervention treatment with antiplatelet and/or anticoagulant therapy has reduced morbidity and mortality due to cardiovascular complications. The purpose of this review is to shed light on the various pharmacologic treatment protocols for treating CLI following endovascular procedures. We reviewed the literature comparing outcomes after antithrombotic treatment for patients with CLI. We characterized antithrombotic therapies into three categories: (1) mono-antiplatelet therapy (MAPT) vs. dual antiplatelet therapy (DAPT), (2) MAPT vs. antiplatelet (AP) + anticoagulant (AC) therapy, and (3) AC vs. AP + AC therapy. Relevant results and statistics were extracted to determine differences in the rates of the following outcomes: (1) re-stenosis, (2) occlusion, (3) target limb revascularization (TLR), (4) major amputation, (5) major adverse cardiac events, (6) all-cause death, and (7) bleeding. Studies suggest that DAPT reduces post-surgical restenosis, TLR, and amputation for diabetic patients, without increasing major bleeding incidences, compared to MAPT. Also, AP + AC therapy provides overall superior efficacy, with no difference in bleeding incidences, compared to antiplatelet alone. Additionally, the effects were significant for restenosis, limb salvage, survival rates, and cumulative rate of above ankle amputation or death. These results suggest that treatment with DAPT and AP + AC might provide better outcomes than MAPT following the endovascular intervention for CLI, and that the ideal treatment may be related to the condition of the individual patient. However, the studies were few and heterogenous with small patient populations. Therefore, further large controlled studies are warranted to confirm these outcomes.

Elevated serum phosphate levels are associated with decreased amputation-free survival after interventions for critical limb ischemia

ObjectiveElevated serum phosphate levels have been associated with increased risks of cardiovascular events and death in several patient populations. The effects of serum phosphate on outcomes in patients with critical limb ischemia (CLI) have not been evaluated. In this study, we assessed the effect of abnormal phosphate levels on mortality and major limb events after surgical intervention for CLI. MethodsA retrospective review was undertaken to identify all patients at a single institution who underwent a first-time open or endovascular intervention for CLI between 2005 and 2014. Patients without recorded postoperative phosphate levels were excluded. Postoperative phosphate levels ≤30 days of the initial operation were recorded, and the mean was calculated. Patients were stratified according to mean phosphate levels (low: <2.5 mg/dL, normal: 2.5-4.5 mg/dL, and high: >4.5 mg/dL). Patient demographics, comorbidities, and operative details were compared in univariate analysis. Multivariable regression and Cox proportional hazard modeling were used to account for patient demographics and comorbid conditions. ResultsWe identified 941 patients, including 42 (5%) with low phosphate, 768 (82%) with normal phosphate, and 131 (14%) with high phosphate. Patients with elevated phosphate were younger and had higher rates of congestive heart failure, diabetes, and dialysis dependence. Bypass was more common among patients with normal phosphate compared with high or low phosphate levels. There was no difference in the Wound, ischemia, and Foot infection (WiFi) classification or TransAtlantic Inter-Society Consensus classification among the cohorts. There were significant differences in 1-year mortality (low: 19%, normal: 17%, high: 33%; P < .01) and 3-year mortality (low: 38%, normal: 34%, high: 56%; P < .01) between phosphate cohorts. Major amputation (low: 12%, normal: 12%, high: 15%) and restenosis (low: 21%, normal: 24%, high: 28%) tended toward worse outcomes among patients with elevated phosphate levels but did not reach statistical significance. After adjustment for baseline characteristics, mortality was higher (hazard ratio [HR], 1.7; 95% confidence interval [CI], 1.3-2.2) and amputation-free survival was lower (HR, 1.5; 95% CI, 1.2-1.9) among patients with elevated compared with normal phosphate levels. A subgroup analysis was then performed to assess dialysis and nondialysis patients separately. Patients with elevated serum phosphate levels maintained a significantly higher risk of mortality in each group (dialysis: HR, 1.8; 95% CI, 1.2-2.6; nondialysis: HR, 1.5; 95% CI, 1.04-2.10). ConclusionsElevated phosphate levels are associated with increased mortality and decreased amputation-free survival after interventions for CLI. Future studies evaluating the effects of phosphate reduction in patients with CLI are warranted.

Time to Wound Healing and Major Adverse Limb Events in Patients with Critical Limb Ischemia Treated with Endovascular Revascularization

There are few studies that quantify the impact of time to wound healing on outcomes after endovascular revascularization of critical limb ischemia (CLI). In this retrospective study, 179 patients with CLI and tissue loss were assessed for adverse events after endovascular therapy. Associations between time to wound healing and outcomes were determined via Cox proportional hazards analysis. The long-term probability of events was assessed with Kaplan-Meier analysis. The primary end point was major adverse limb events (MALE-major amputation, surgical endarterectomy, or bypass). Secondary end points were major amputation, need for repeat endovascular therapy, and mortality. After multivariable adjustment for time-dependent wound healing, age, renal function, diabetes, and Rutherford class, independent predictors of MALE included the presence of an unhealed wound (hazard ratio [HR], 5.2; 95% confidence interval (CI), 2.3-11.8; P<0.0001) and creatinine≥2.0 (HR, 2.4; 95% CI, 1.4-4.3; P=0.003). On Kaplan-Meier analysis, the probability of MALE was greater in patients with unhealed wounds compared with healed wounds (log-rank P<0.0001). Patients whose wounds healed within 4months had a lower probability of MALE than patients who did not heal by 4months (log-rank, P=0.04). Unhealed wounds were also independently associated with major amputation (HR, 9.0; 95% CI, 2.6-31.1; P=0.0004), and patients whose wounds healed by 3months had less major amputation (log-rank, P=0.04). Unhealed wounds were independently associated with increased risk of mortality (HR, 42.7; 95% CI, 5.7-319.0; P=0.002) but not repeat revascularization. Unhealed wounds are an independent risk factor for MALE, major amputation, and mortality after endovascular treatment of CLI. Wound healing within 3months is associated with less risk of major amputation, and within 4months less risk of MALE. A focus should be on achieving wound healing as fast as possible in this population.

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

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 1year 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 5years after treatment. 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. 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. 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.

Endovascular Treatment of Infrapopliteal Peripheral Artery Disease.

Endovascular treatment of infrapopliteal disease is focused on the treatment of patients with rest pain or critical limb ischemia (CLI) due to severe atherosclerotic disease. While the evidence base surrounding the comparative effectiveness of endovascular intervention vs. surgery is lacking, many operators have adopted an "endovascular first" approach to the treatment of infrapopliteal atherosclerotic disease due to the lower morbidity of these procedures. This manuscript reviews current data on the endovascular treatment of CLI, including a comparison of endovascular and surgical approaches, current indications for and outcomes with balloon angioplasty of infrapopliteal PAD, angiosome-guided revascularization, and emerging technologies to improve long-term vessel patency after endovascular intervention.

Indications and results of endovascular therapy of critical limb ischemia

Critical limb ischemia (CLI) is the most severe form of peripheral artery occlusive disease and is characterized by high amputation, morbidity and mortality rates. Therefore, revascularization is the essential step in therapy for retention of the affected limb. Although for a long time bypass surgery represented the gold standard in the treatment of CLI, in recent years there has been a disproportionate increase of endovascular treatment despite the lack of level-data. In this review the indications and results of endovascular therapy of CLI are presented on the basis of published data. A literature search was carried out to identify publications that compared the results of endovascular and surgical therapy as well as observational studies about different endovascular techniques. The BASIL study provided the highest quality data comparing endovascular and surgical treatment of CLI. The long-term data of the BASIL trial showed that apart from patients with a suitable vein and a life expectancy of more than 2 years, first line endovascular therapy is equivalent to surgical treatment. The equivalence could also be demonstrated in a meta-analysis comparing operative and endovascular treatment of CLI. The CLI is a disease with high mortality and morbidity risks. Due to the comparable amputation-free survival times with lower complication rates in the published data, in most patients an endovascular first strategy in experienced centers can be justified.

Clinical outcomes of endovascular treatments for critical limb ischemia with chronic total occlusive lesions limited to below-the-knee arteries

Diabetes mellitus tends to have the greatest impact on the smaller vessels and contributes significantly to occlusive disease from the popliteal artery distally. To evaluate the clinical outcomes after a balloon angioplasty with or without stent placement in diabetic patients with critical limb ischemia (CLI) by chronic total occlusion (CTO) limited to below-the-knee (BTK) arteries. From August 2005, patients who presented CLI and CTO limited to the BTK arteries, and who underwent endovascular treatment, were included in this study. The primary endpoints evaluated were technical success, limb salvage, and primary patency. The secondary endpoints evaluated were 30-day access site, intervention site, and systemic complications. Patency and limb salvage were evaluated using the Kaplan-Meier method and compared using Fisher's exact test. The BTK endovascular treatment (EVT) was performed on 64 limbs. Technical success rate was 93.8% and limb salvage rate was 90.6%. Three of four limbs with technical failure and three of 60 limbs with technical success underwent BTK amputation and the comparison of these rates were significantly different (75% vs. 5%, P = 0.002). Primary patency rates for the limbs were 75% and 59.1% at 6-month and 12-month follow-up, respectively. Minor complications disappeared through the follow-up periods and there was no 30-day complication or systemic adverse events for the treated vessel. Even though EVT for CLI in patients with diabetes and CTO in isolated BTK arteries does not have comparable primary patency, it can lead to a very high rate of limb salvage. This result can accentuate the importance of more blood flow to the foot by means of successful revascularization using EVT rather than long-term patency in CTO of isolated BTK arteries.

Autologous Bone Marrow Mononuclear Cell Therapy Produces Durable Benefits in Limb Salvage at Five Years Post-Treatment

Objectives: We have previously demonstrated that autologous bone marrow mononuclear cell (ABMNC) therapy improves measures of limb perfusion, rest pain, wound healing, and amputation free survival (AFS) at one year in patients with critical limb ischemia (CLI). Long term durability of ABMNC therapy for critical limb ischemia (CLI) remains unknown. The objective of this current study is to evaluate long term clinical outcomes five years after treatment. Methods: Data were retrospectively gathered from a database and via a survey sent to patients with CLI who had previously underwent intra-muscular transplantation of ABMNCs in the most symptomatic limb. 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 during the time from treatment to follow-up were tabulated. Results: Twenty-one of the 24 (87.5%) patients who completed the initial one year Phase I trial responded to a detailed questionnaire Interval from initial treatment was 188.2 ±12.3 weeks, range:129- 278).At five years AFS was 74% (95% CI, 0.53-0.86; P < .05) (Fig 1), freedom from major amputation was 78% (95% CI, 0.57-0.89; P < .05) (Fig 2) and freedom from MALE was 65 % (95% CI, 0.45- 0.79; P < .05) (Fig 3).Three patients (14.2%) had major cardiac events. There were no incidences of malignancies or diagnoses of proliferative retinopathy. Fifteen patients (71.4%) report continued improvement in pain-free walking. Nineteen (90.4%) patients felt that the study was of significant medical value and would participate again.Fig 2View Large Image Figure ViewerDownload Hi-res image Download (PPT)Fig 3View Large Image Figure ViewerDownload Hi-res image Download (PPT) Conclusions: ABMNC therapy provides long term freedom from AFS, major amputation, and MALE that are comparable to surgical and endovascular interventions for CLI. Furthermore this study eliminates the concerns for tumor genesis and proliferative retinopathy associated with angiogenic therapies.