Influence of a Novel Morphology-Driven Classification on Limb Salvage after Isolated Tibial Intervention for Chronic Limb Threatening Ischemia

BACKGROUND

Infra-popliteal interventions for chronic limb-threatening ischemia (CLTI) can be impacted by the morphology of the tibial vessels. The aim of this study was to examine the impact of a novel morphology-driven classification on the outcomes of isolated tibial intervention for CLTI.

METHODS

A database of patients undergoing isolated tibial interventions for CLTI at a single center between 2010 and 2020 was retrospectively queried. Patients with isolated infra-popliteal disease were identified, and their anatomy was scored as present or absent for lesion calcification (1 point), target vessel diameter<3.0 mm (1 point), lesion length>300 mm (1 point), and poor pedal runoff score (1 point). Patients were then divided into 3 groups: low risk (0 or 1 points), moderate risk (2 points), and high risk (3 or 4 points). Intention to treat analysis by the patient was performed. Limb-based patency (the absence of reintervention, occlusion, critical stenosis [>70%], or hemodynamic compromise with ongoing symptoms of CLTI as it related to the patency of the preoperatively determined target artery pathway) was assessed. Patient-oriented outcomes of amputation-free survival (AFS; survival without major amputation) and freedom from major adverse limb events (MALE; above ankle amputation of the index limb or major reintervention: new bypass graft, jump/interposition graft revision) were evaluated.

RESULTS

1,607 patients (55% male, average age 60 years, 3,846 vessels) underwent tibial intervention for CLTI. The majority of the patients were diabetic and of Hispanic origin. Morphologically, 27%, 31%, and 42% of the vessels were categorized as low risk, moderate risk, and high risk, respectively. There was a significant worsening of the infra-popliteal Global Limb Anatomic Staging System (GLASS) grading as the morphological risk increased. The 30-day major adverse cardiac events (MACE) were equivalent across the groups and were under the stated objective performance goal (OPG) of ≤10%. In contrast, both the 30-day MALE and the 30-day major amputations were significantly different across the groups, with the low-risk group remaining under the OPG of ≤9% and ≤4%, respectively, while the moderate risk and high risk exceeded the goal threshold. For the OPG, freedom from MALE was 60 ± 5%, 46 ± 5%, and 22 ± 9% at 5 years for low-, moderate-, and high-risk groups, respectively (mean ± standard error of the mean; P = 0.008). Overall AFS was 55 ± 5%, 37 ± 6%, and 18 ± 7% at 5 years for low-, moderate-, and high-risk groups, respectively (mean ± standard error of the mean; P = 0.003).

CONCLUSIONS

Tibial anatomic morphology impacts isolated tibial endovascular intervention with adverse morphology associated with poorer short- and long-term outcomes. Risk stratification based on anatomic predictors should be an additional consideration as one intervenes on infra-popliteal vessels for CLTI.

The Characteristics of Dialysis Membranes: Benefits of the AN69 Membrane in Hemodialysis Patients

Patients undergoing hemodialysis (HD) experience serious cardiovascular complications, through malnutrition, inflammation, and atherosclerosis. Amputation for peripheral arterial disease (PAD) is more prevalent in patients undergoing HD than in the general population. In addition, revascularization procedures in dialysis patients are often associated with subsequent amputation and high mortality rates. To improve the prognosis of dialysis patients, malnutrition and inflammation must be properly treated, which necessitates a better understanding of the characteristics of dialysis membranes. Herein, the characteristics of several dialysis membranes were studied, with a special reference to the AN69 membrane, noting several similarities to low-density lipoprotein (LDL)-apheresis, which is also applicable for the treatment of PAD. Both systems (LDL-apheresis and AN69) have anti-inflammatory and anti-thrombogenic effects because they use a negatively charged surface for extracorporeal adsorptive filtration from the blood/plasma, and contact phase activation. The concomitant use of both these therapeutic systems may have additive therapeutic benefits in HD patients. Here, we reviewed the characteristics of dialysis membranes and benefits of the AN69 membrane in dialysis patients.

Effect of Comorbidities on Outcomes of Infrapopliteal Angioplasty in Patients with Chronic Limb-Threatening Ischemia

OBJECTIVE

This subgroup analysis aimed to evaluate the effect of comorbidities on infrapopliteal angioplasty outcomes in patients with chronic limb-threatening ischemia (CLTI).

METHODS

This was an observational study evaluating eligible CLTI patients aged >18 years who underwent infrapopliteal angioplasty between April 2014 and May 2017 at a tertiary care center. Subgroup analyses were based on (1) baseline glycated hemoglobin (HbA1c ≤6.5% vs >6.5%), (2) presence/absence of chronic kidney disease (CKD), and (3) control of lipid parameters.

RESULTS

A total of 231 patients with 332 infrapopliteal vessels were treated. While diabetes was prevalent in all participants, hypertension, coronary artery disease, and CKD were reported in 76.6%, 46.3%, and 25.5% of patients at baseline, respectively. The overall technical success rate was 84.4%, and the patency rate at 6 months was 82.04%. Patency at 6 months, wound healing, in-line flow, and complete plantar arch formation were numerically higher in patients with HbA1c ≤6.5% versus >6.5%, but all comparisons were nonsignificant. According to multivariable analysis, the odds of wounds not healing was 2.38 times higher (odds ratio [OR] = 2.4, 95% confidence interval [CI]: 1.2 to 4.5) and developing plantar arch was 5.88 times higher (OR = 5.9, 95% CI: 1.3 to 25) among patients with CKD compared with patients without CKD.

CONCLUSIONS

The 6-month outcomes of infrapopliteal angioplasty may be better in patients with controlled versus uncontrolled glycemic levels. Control of lipid parameters may not have a significant influence on outcomes, especially in patients on statin therapy. The short-term outcomes may be similar in patients with and without CKD.

Autologous Granulocyte Colony-Stimulating Factor-Mobilized Peripheral Blood CD34 Positive Cell Transplantation for Hemodialysis Patients with Critical Limb Ischemia: A Prospective Phase II Clinical Trial

Critical limb ischemia (CLI) is a devastating disease in patients undergoing hemodialysis (HD). Based on the unsatisfactory results of autologous mononuclear cell transplantation for patients with CLI undergoing HD, we conducted a phase II clinical trial to evaluate the safety and efficacy of granulocyte colony‐stimulating factor (G‐CSF)‐mobilized peripheral blood‐derived autologous purified CD34 positive (CD34+) cell transplantation for CLI in patients undergoing HD. Six patients with CLI (two with Rutherford category 4 and four with Rutherford category 5) were enrolled. As for primary endpoint, there were no major adverse events related to this therapy. As for efficacy, the amputation‐free survival rate was 100% at 1 year after cell therapy. Both rest pain scale and ulcer size were significantly improved as early as 4 weeks after therapy compared with baseline (p < .01), and three out of five ulcers completely healed within 12 weeks after cell transplantation. Clinical severity, including Fontaine scale and Rutherford category, significantly improved at 24 weeks after cell transplantation (p < .05), and further improved at 52 weeks (p < .01) compared with baseline. The improvement rate from CLI stage to non‐CLI stage was 83.3% at 52 weeks. Toe skin perfusion pressure and absolute claudication distance were also significantly improved. In conclusion, G‐CSF‐mobilized peripheral blood CD34+ cell transplantation was safe, feasible, and effective for patients with CLI undergoing HD. stem cells translational medicine2018;7:774–782

Open Versus Endovascular Revascularization of Below-Knee Arteries in Patients With End-Stage Renal Disease and Critical Limb Ischemia

Background:

Evaluation of below-the-knee open revascularization (OR) versus endovascular revascularization (EVT) in patients with end-stage renal disease and critical limb ischemia (CLI) was performed.

Patients and Methods:

Seventy-seven dialysis patients with CLI and infrapopliteal involvement from 2007 to 2017 were included. Thirty-five patients received OR and 42 patients were treated with EVT. Survival, amputation-free survival (AFS) and wound-healing were evaluated. Furthermore, both groups were analyzed for differences as to anatomic (lesion length, runoff, pedal arch classification) and clinical (VSG risk score, WIfI score) characteristics.

Results:

Amputation-free survival (1-year AFS: OR 54.5% vs 47.6% in EVT, 2-year AFS OR 38.3% vs 23.9% EVT, P = .201) did not significantly differ between OR and EVT nor did the wound healing rate (29% OR vs 31% EVT, P = .532). Overall survival was noticeably poor (1-year survival: 66.7% in OR and 49% in EVT, 2-year survival OR 47.4% vs EVT 27.7%; P = .088); evaluation of peripheral runoff (Rutherford score 6.9 OR vs 7.1 EVT, P = .499) and pedal arch classification as well as WIfI or VSG risk score (9.8 OR vs 9.6 EVT, P = .673) could not detect significant differences as to both the groups. Treated median lesion length was significantly increased in OR patients (OR 26 cm vs EVT 7 cm, P < .001), whereas the incidence of major adverse cardiac events was higher in EVT patients (67% in EVT vs 40% OR, P = .023).

Conclusion:

OR and EVT showed comparable outcomes as to AFS and wound healing. Poor overall survival remains the determining factor in patients with ESRD having CLI. Both groups differ in terms of anatomic features as lesion length and severity of comorbidities; considering the comparable long-term outcomes, decision-making should be based on these premises; individually applied, each method can contribute to limb salvage, although the overall survival remains limited.

Hemodialysis patients have worse outcomes after infrageniculate revascularization procedures

BACKGROUND

Hemodialysis (HD) has been shown to be an independent predictor of poor outcomes after femoropopliteal revascularization procedures in patients with chronic limb-threatening ischemia. However, HD patients tend to have isolated infrageniculate disease, an anatomic risk factor for inferior patency. We aimed to compare outcomes for HD versus non-HD patients after infrageniculate open lower extremity bypass (LEB) and endovascular peripheral vascular interventions (PVIs).

METHODS

Data from the Society for Vascular Surgery Vascular Quality Initiative database (2008-2014) were analyzed. All patients undergoing infrageniculate LEB or PVI for rest pain or tissue loss were included. One-year primary patency (PP), secondary patency (SP), and major amputation outcomes were analyzed for HD versus non-HD patients stratified by treatment approach using both univariable and multivariable analyses.

RESULTS

A total of 1688 patients were included, including 348 patients undergoing LEB (HD = 44 versus non-HD = 304) and 1340 patients undergoing PVI (HD = 223 versus non-HD = 1117). Patients on HD more frequently underwent revascularization for tissue loss (89% versus 77%, P < 0.001) and had ≥2 comorbidities (91% versus 76%, P < 0.001). Among patients undergoing LEB, 1-y PP (66% versus 69%) and SP (71% versus 78%) were similar for HD versus non-HD (P ≥ 0.25) groups, but major amputations occurred more frequently in the HD group (27% versus 14%; P = 0.03). Among patients undergoing PVI, 1-y PP (70% versus 78%) and SP (82% versus 90%) were lower and the frequency of major amputations was higher (27% versus 10%) for HD patients (all, P ≤ 0.02). After correcting for baseline differences between the groups, outcomes were similar for HD versus non-HD patients undergoing LEB (P ≥ 0.21) but persistently worse for HD patients undergoing PVI (all, P ≤ 0.006).

CONCLUSIONS

HD is an independent predictor of poor patency and higher risk of major amputation after infrageniculate endovascular revascularization procedures for the treatment of chronic limb-threatening ischemia. The use of endovascular interventions in these higher risk patients is not associated with improved limb salvage outcomes and may be an inappropriate use of healthcare resources.

Predictive Parameters for Clinical Outcome in Patients with Critical Limb Ischemia Who Underwent Percutaneous Transluminal Angioplasty (PTA): A Systematic Review

Purpose

To identify possible risk factors in predicting clinical outcome in critical limb ischemia (CLI) patients undergoing percutaneous transluminal angioplasty (PTA).

Materials and Methods

PubMed and EMBASE were searched for studies analyzing CLI and clinical outcome after PTA from January 2006 to April 2017. Outcome measures were ulcer healing, amputation free survival (AFS)/limb salvage and overall survival. Data on predictive factors for ulcer healing, AFS/limb salvage and survival were extracted.

Results

Ten articles with a total of 2448 patients were included, all cohorts and based on prospective-designed databases. For ulcers, it seems that complete healing can be achieved in most of the patients within 1 year. No significant predictive factors were found. AFS/limb salvage: AFS rates for 1, 2 and 3 years ranged from 49.5 to 75.2%, 37 to 58% and 22 to 59%, respectively. Limb salvage rates for 1, 2 and 3 years ranged from 71 to 95%, 54 to 93.3% and 32 to 92.7%, respectively. All studies had different univariate and multivariate outcomes for predictive factors; however, age and diabetes were significant predictors in at least three studies. Survival: Survival rates for 1, 2 and 3 years ranged from 65.4 to 91.5%, 45.7 to 76% and 37.3 to 83.1%, respectively. Different predictive factors were found; however, age was found in 2 out of 5 studies reporting on predictive factors.

Conclusions

In several studies two factors, age and diabetes, were found as predictive factors for AFS/limb salvage and survival in patients with CLI undergoing PTA. Therefore, we believe that these factors should be taken into account in future research.

Level of Evidence

Level 2a.

Semiquantitative assessment of tibial artery calcification by computed tomography angiography and its ability to predict infrapopliteal angioplasty outcomes

OBJECTIVE

Tibial artery calcification (TAC) is associated with increased risk of amputation and mortality in peripheral artery disease. We sought to investigate whether the severity of TAC based on semiquantitative analysis of computed tomography angiography (CTA) can predict outcomes of endovascular therapy in patients with critical limb ischemia.

METHODS

We reviewed medical records of 124 patients who underwent lower extremity CTA before intervention. Based on CTA, TAC severity was categorized into three groups: minimal calcification (MC; n = 43), intermediate calcification (IC; n = 36), or extensive calcification (EC; n = 45). Immediate and late outcomes of infrapopliteal interventions were compared, and predictors of the outcomes were investigated.

RESULTS

The categorized severity of target TAC correlated with the log-transformed TAC score (r = 0.873; P < .001). The EC group was younger and had more diabetes and chronic kidney disease compared with the MC or IC group (all P < .001). The technical success was lower in the EC group (71.1%) than in the MC (95.3%) or IC (91.7%) group (P = .001). The survival free of unplanned amputations at 2 years was significantly lower in the EC group (58.9%) than in the MC (79.0%) or IC (95.3%) group (P < .001). Extensive TAC was an independent predictor of technical success (hazard ratio, 0.02; 95% confidence interval, 0.00-0.45; P = .014) and unplanned amputation (hazard ratio, 9.90; 95% confidence interval, 2.05-47.75; P = .004).

CONCLUSIONS

The categorized severity of TAC by semiquantitative analysis of CTA correlated with TAC score, and extensive TAC was associated with a lower technical success rate of angioplasty and an increased incidence of unplanned amputation.

Relation of Baseline Renal Dysfunction With Outcomes in Patients Undergoing Popliteal and Infrapopliteal Percutaneous Peripheral Arterial Interventions

Renal dysfunction is a major risk factor for peripheral arterial disease (PAD). Infrapopliteal PAD is associated with more co-morbid conditions and worse prognosis than suprapopliteal PAD. Long-term outcomes of patients with renal dysfunction and popliteal or infrapopliteal PAD undergoing peripheral vascular intervention (PVI) are not well described. We retrospectively evaluated long-term outcomes in 726 patients undergoing infrapopliteal PVI categorized into 3 glomerular filtration rate (GFR)-based groups: GFR (≥60 ml/min/1.73 m(2)), GFR (<60 ml/min/1.73 m(2)), and those on dialysis. At mean follow-up of 36 ± 20 months, amputation rates were 3%, 5%, and 11% with mortality rates of 23%, 36%, and 56% in normal renal function, chronic kidney disease (adjusted odds ratio [OR] for amputation 1.75, 95% CI 0.73 to 4.21; adjusted OR for mortality 1.53, 95% CI 1.05 to 2.23, p = 0.028), and dialysis (adjusted OR for amputation 2.43, 95% CI 0.84 to 7.02, p = 0.100; adjusted OR for mortality 4.51, 95% CI 2.46 to 8.26, p <0.0001) groups, respectively. Repeat revascularization was similar in all 3 groups at roughly 25%. In conclusion, chronic kidney disease and dialysis were associated with increased major amputations and mortality in patients who received PVI for popliteal and infrapopliteal PAD.

[Revascularisation of the aorta, of the renal and of the lower limb arterial systems]

Revascularisation aims to create a patent lumen in an acutely or chronically occluded or stenosed vessel. Interventional radiology has developed and used minimally invasive methods for decades concurring surgical methods and medical therapy. Innovative fields in healthcare may be handicapped since revolutionary solutions usually gain wide acceptance slowly and the results of randomized controlled trials are reported late. At present endovascular recanalization, dilatation and stent placement have achieved a well-established role in the treatment of stenosis or occlusion of the aorta, and renal and peripheral arteries.