Chapter I: Definitions, epidemiology, clinical presentation and prognosis

Intravascular lithotripsy-assisted percutaneous deep vein arterialization for no-option chronic limb-threatening patients and heavily calcified tibial occlusive disease

PURPOSE

To report the first chronic limb-threatening ischemia (CLTI) patients who underwent an intravascular lithotripsy (IVL)-assisted percutaneous deep vein arterialization (pDVA).

CASE REPORT 1

An 81-year-old patient presented with CLTI and a heavily calcified lesion of the popliteal artery and tibioperoneal trunk (TPT), with a distal tibial and foot arch occlusion. The patient underwent IVL and drug-coated balloon angioplasty for the distal popliteal artery and of the TPT to improve the inflow prior to pDVA. The wound situation remained stable without secondary procedure until the patient`s deaths due to complications of urosepsis 3 months later.

CASE REPORT 2

A 64-year-old patient with rest pain of the left limb with a single-vessel tibial run-off (peroneal artery) and occluded pedal arch was treated with 3.5 mm IVL followed by a successful pDVA as mentioned above. IVL performed in the proximal posterior tibial artery to optimize the inflow to the circuit and change the compliance of the crossing point from the arterial to the vein system. The patient underwent repeat angioplasty of the plantar vein arch 5 months after the index procedure and thereafter remained asymptomatic during 2 years of follow-up.

CONCLUSION

The combined use of IVL and pDVA could improve the patency of the reconstruction with clinical benefits in no-option CTLI patients.

Effect of acidosis on adipose-derived stem cell impairment and gene expression

Based on disappointing results of stem cell-based application in clinical trials for patients with critical limb ischemia, we hypothesized that the acidic environment might be the key factor limiting cell survival and function. In the present study, we used microdialysis to determine presence of acidosis and metabolic imbalance in critical ischemia. Moreover, we explored the effect of extracellular acidosis on adipose-derived stem cells (ADSCs) at molecular and transcriptional level. Our data demonstrate that low pH negatively regulates cell proliferation and survival, also, it results in cell cycle arrest, mitochondrial dynamics disorder, DNA damage as well as the impairment of proangiogenic function in a pH-dependent manner. Further transcriptome profiling identified the pivotal signaling pathways and hub genes in response to acidosis. Collectively, these findings provide strong evidences for a critical role of acidosis in ADSCs impairment with ischemic condition and suggest treatments focus on tissue pH balance and acidosis-mediated hub genes may have therapeutic potential in stem cell-based application.

Expression level and clinical significance of LncRNA PVT1 in the serum of patients with LEASO

Objective

Our study aims to investigate the long non-coding RNA plasmacytoma variant translocation 1 (lncRNA PVT1) in lower extremity arteriosclerosis obliterans (LEASO) patient serum and its clinical significance in LEASO.

Patients and Methods

From July 2021 to April 2022, 133 LEASO patients diagnosed at the Qingdao Municipal Hospital were included. Among them, 44 complicated with coronary artery disease (CAD) were classified as the LEASO with CAD group. The remaining 89 were marked as the LEASO group, which was classified into single (n = 48) and double (n = 41) lower limb groups, with the former being subclassified into the left (n = 28) and right (n = 20) lower limb groups based on the affected sites. Fifty healthy individuals who came to our hospital for physical examination during the same period were randomly included and defined as the Healthy Control group. PVT1 expression was detected in serum samples from each group using a quantitative reverse transcriptase-polymerase chain reaction , and differences in expression levels were calculated. The ankle-brachial index (ABI) of patients in the LEASO group was measured using a sphygmomanometer, and its correlation with PVT1 was analyzed. Clinical data and laboratory test results (including blood routine, liver and renal function, and blood lipids) were collected for all patients upon admission. Logistic regression analyses were performed to determine the influence of PVT1 and laboratory test results on LEASO. The diagnosis and prediction of LEASO were obtained by combing PVT1 with laboratory test indicators.

Results

It was found that lncRNA PVT1 expression was the highest in the serum of the LEASO with CAD group, followed by the LEASO and control groups (P < 0.05). Within the LEASO group, no significant difference in PVT1 expression was seen between the left and right limbs (P > 0.05), nor between the single and double lower limb groups. Furthermore, the PVT1 expression increased with the Rutherford grades, indicating a negative correlation between PVT1 and ABI. Logistic regression analysis revealed that triglycerides (OR = 2.972, 95% CI [1.159-7.618]), cholesterol (OR = 6.655, 95% CI [1.490-29.723]), C-reactive protein (OR = 1.686, 95% CI [1.218-2.335]), and PVT1 (OR = 2.885, 95% CI [1.350-6.167]) were independent risk factors for LEASO. Finally, strong sensitivity was observed in the receiver operating characteristic curve when combining PVT1 with meaningful laboratory indicators to diagnose and predict LEASO.

Conclusion

lncRNA PVT1 promotes LEASO occurrence and progression and is related to atherosclerosis severity. The expression of PVT1 was negatively correlated with ABI. Logistic regression analysis suggested that blood lipid levels and inflammatory reactions might be related to LEASO occurrence. PVT1 was incorporated into laboratory indicators to predict LEASO. The subject's working curve area was large, and the prediction results were highly sensitive.

Editor's Choice - Quality Assessment of European Society for Vascular Surgery Clinical Practice Guidelines

OBJECTIVE

An increasing number of clinical practice guidelines (CPGs) have emerged over recent years. To have clinical utility, they need to be rigorously developed and scientifically robust. Instruments have been developed to assess the quality of clinical guideline development and reporting. The aim of this study was to evaluate CPGs from the European Society for Vascular Surgery (ESVS) using the Appraisal of Guidelines for Research and Evaluation II (AGREE II) instrument.

METHODS

CPGs published by the ESVS during the period January 2011 to January 2023 were included. Two independent reviewers assessed the guidelines after receiving training in the use and application of the AGREE II instrument. Inter-reviewer reliability was assessed with the intraclass correlation coefficient. Maximum scaled scores were 100. Statistical analysis was performed using SPSS Statistics v.26.

RESULTS

Sixteen guidelines were included in the study. Good inter-reviewer score reliability was found on statistical analysis (> 0.9). The mean ± standard deviation domain scores were 68.1 ± 20.3% for scope and purpose, 57.1 ± 21.1% for stakeholder involvement, 67.8 ± 19.5% for rigour of development, 78.1 ± 20.6% for clarity of presentation, 50.3 ± 15.4% for applicability, 77.6 ± 17.6% for editorial independence, and 69.8 ± 20.1% for overall quality. Stakeholder involvement and applicability have improved in quality over time but are still the lowest scoring domains.

CONCLUSION

Most ESVS clinical guidelines are of high quality and reporting. There is scope for improvement, specifically by addressing the domains of stakeholder involvement and clinical applicability.

Atherosclerotic-Derived Endothelial Cell Response Conducted by Titanium Oxide Nanotubes

Atherosclerosis lesions are described as the formation of an occlusive wall-vessel plaque that can exacerbate infarctions, strokes, and even death. Furthermore, atherosclerosis damages the endothelium integrity, avoiding proper regeneration after stent implantation. Therefore, we investigate the beneficial effects of TiO₂ nanotubes (NTs) in promoting the initial response of detrimental human atherosclerotic-derived endothelial cells (AThEC). We synthesized and characterized NTs on Ti6Al4V by anodization. We isolated AThEC and tested the adhesion long-lasting proliferation activity, and the modulation of focal adhesions conducted on the materials. Moreover, ultrastructural cell-surface contact at the nanoscale and membrane roughness were evaluated to explain the results. Our findings depicted improved filopodia and focal adhesions stimulated by the NTs. Similarly, the NTs harbored long-lasting proliferative metabolism after 5 days, explained by overcoming cell-contact interactions at the nanoscale. Furthermore, the senescent activity detected in the AThEC could be mitigated by the modified membrane roughness and cellular stretch orchestrated by the NTs. Importantly, the NTs stimulate the initial endothelial anchorage and metabolic recovery required to regenerate the endothelial monolayer. Despite the dysfunctional status of the AThEC, our study brings new evidence for the potential application of nano-configured biomaterials for innovation in stent technologies.

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.

Editor's Choice - Effect of Physical Activity and Tobacco Use on Mortality and Morbidity in Patients with Peripheral Arterial Disease After Revascularisation: A Korean Nationwide Population Based Cohort Study

OBJECTIVE

To investigate the effects of physical activity (PA) and tobacco use on adverse clinical outcomes after revascularisation for peripheral arterial disease (PAD) in the Western Pacific region, where PAD cases and tobacco use are among the highest in the world.

METHODS

This was a retrospective cohort study using the Korean National Health Insurance Service (NHIS) database and included patients who had received revascularisation for PAD between 2010 and 2015. They were categorised as active or inactive based on the number of days per week they engaged in PA and as current or non-tobacco users (self report). The primary outcome was all cause mortality. Secondary outcomes included major adverse outcome (a composite of all cause mortality, myocardial infarction, and stroke) and major adverse limb event (MALE, a composite of amputation and recurrent revascularisation).

RESULTS

The relatively healthy cohort comprised 8 324 patients (mean age 64.7 years; 76.9% male) following revascularisation for PAD. Among them, 32.7% were inactive and 26.4% were tobacco users. Active patients had better outcomes than inactive patients (all cause mortality adjusted hazard ratio [adjHR] 0.766; 95% CI 0.685 - 0.855, major adverse outcome adjHR 0.795; 95% CI 0.719 - 0.878, MALE adjHR 0.858; 95% CI 0.773 - 0.953). Tobacco users had poorer outcomes than non-users (all cause mortality adjHR 1.279; 95% CI 1.124 - 1.456, major adverse outcome adjHR 1.263; 95% CI 1.124 - 1.418, MALE adjHR 1.291; 95% CI 1.143 - 1.458).

CONCLUSION

Even after receiving revascularisation for PAD, a sizable proportion of patients were physically inactive and used tobacco, leading to adverse clinical outcomes such as death, cardiovascular morbidity, and amputation in Korea. These modifiable risk factors should be addressed systematically, and a comprehensive approach including supervised exercise programmes and tobacco cessation is needed in patients with PAD.

Risk of Peripheral Arterial Occlusive Disease with Periodontitis and Dental Scaling: A Nationwide Population-Based Cohort Study

Periodontitis (PD) is a common oral disease associated with various other diseases, particularly those affecting the cardiovascular system. This study explored whether peripheral artery occlusive disease (PAOD) is associated with PD and dental scaling. This study was a retrospective cohort study design from 2000 to 2018. The study population was newly diagnosed with periodontitis. The comparison group was defined as never diagnosed with periodontitis. The outcome variable was defined with the diagnosis of peripheral arterial occlusive disease (PAOD). The propensity score matching was performed by age, sex, comorbidities, and dental scaling between the two groups. Kaplan-Meier analysis was used to calculate the cumulative incidence of PAOD among the two groups. To perform the independent risk of the PAOD group, the multivariate Cox proportional hazard model was used to estimate the hazard ratios. First, 792,681 patients with PD and 458,521 patients with no history of PD were selected from Taiwan's Longitudinal Health Insurance Database, which comprises the data of two million beneficiaries. After propensity score matching between the PD and non-PD groups for age, sex, comorbidities, and dental scaling, 357,106 patients in each group were analyzed for PAOD risk. The incidence density, relative risk, and cumulative incidence of PAOD were higher in the PD group than in the non-PD group. After adjusting for all variables, the risk of PAOD for the PD group was greater than for the non-PD group (adjusted hazard ratio = 1.03; 95% CI, 1.01-1.06). Undergoing at least one dental scaling procedure reduced the risk of PAOD. Age over 65 years was also a risk factor. In conclusion, patients with PD have an increased risk of PAOD. In addition, our results can lead to increased attention to oral hygiene, as dental scaling has a trend towards a lower risk of PAOD.

Effect of Revascularization on Intramuscular Vascular Endothelial Growth Factor Levels in Peripheral Arterial Disease

Vascular endothelial growth factor (VEGF) is a potent driver of angiogenesis, which may help to relieve ischemia in peripheral arterial disease (PAD). We aimed to investigate the role of intramuscular VEGF in ischemic and non-ischemic skeletal muscle in PAD patients before and after surgical or endovascular revascularization and different stages of PAD. Biopsies of the gastrocnemius and vastus muscles from twenty PAD patients with stenosis or occlusion of the superficial femoral artery were obtained both during revascularization and 8 weeks postoperatively. The gastrocnemius muscle was considered ischemic, while vastus muscle biopsies served as intraindividual controls. The levels of vascular endothelial growth factor in muscle lysates were then determined by ELISA. Preoperative VEGF levels were significantly higher in ischemic muscles compared to the controls (98.07 ± 61.96 pg/mL vs. 55.50 ± 27.33 pg/mL, p = 0.004). Postoperative values decreased significantly (p = 0.010) to 54.83 ± 49.60 pg/mL in gastrocnemius biopsies. No significant change was observed in vastus muscle biopsies, with mean postoperative VEGF values found at 54.16 ± 40.66 pg/mL. Since all patients still had indications for revascularization, impairment of angiogenesis mechanisms can be assumed. More research about angiogenesis in PAD is needed with the ultimate goal to improve conservative treatment.

Molecular basis of the effect of atorvastatin pretreatment on stem cell therapy in chronic ischemic diseases – critical limb ischemia

Autologous stem cell therapy is the most promising alternative treatment in patients with chronic ischemic diseases, including ischemic heart disease and critical limb ischemia, which are characterized by poor prognosis related to serious impair of quality of life, high risk of cardiovascular events and mortality rates. However, one of the most serious shortcomings of stem cell transplantation are low survival after transplantation to the site of injury, as large number of stem cells are lost within 24 hours after delivery. Multiple studies suggest that combination of lipid-lowering drugs, statins, and stem cell transplantation might improve therapeutic efficacy in regenerative medicine. Statins are inhibitors of HMG-CoA reductase and belong to recommended therapy in all patients suffering from critical limb ischemia. Statins possess non-lipid effects which involve improvement of endothelial function, decrease of vascular inflammation and oxidative stress, anti-cancer and stem cell modulation capacities. These non-lipid effects are explained by inhibition of mevalonate synthesis via blocking isoprenoid intermediates synthesis, such as farnesylpyrophospate and geranylgeranylpyrophospate and result in modulation of the PI3K/Akt pathway. Moreover, statin-mediated microRNA regulation may contribute to the pleiotropic functions. MicroRNA interplay in gene regulatory network of IGF/Akt pathway may be of special significance for the treatment of critical limb ischemia. We assume further studies are needed for detailed analysis of statin interactions with microRNA at the molecular level and their link to PI3K/Akt and IGF/Akt pathway in stem cells, which are currently the most promising treatment strategy used in chronic ischemic diseases.

A Systematic Review and Critical Appraisal of Peri-Procedural Tissue Perfusion Techniques and their Clinical Value in Patients with Peripheral Arterial Disease

OBJECTIVE

Many techniques have been introduced to enable quantification of tissue perfusion in patients with peripheral arterial disease (PAD). Currently, none of these techniques is widely used to analyse real time tissue perfusion changes during endovascular or surgical revascularisation procedures. The aim of this systematic review was to provide an up to date overview of the peri-procedural applicability of currently available techniques, diagnostic accuracy of assessing tissue perfusion and the relationship with clinical outcomes.

DATA SOURCES

MEDLINE, Embase, CINAHL, and the Cochrane Central Register of Controlled Trials.

REVIEW METHODS

This systematic review was conducted in accordance with the Preferred Reporting Items for Systematic review and Meta-Analysis (PRISMA) guidelines. Four electronic databases were searched up to 31 12 2020 for eligible articles: MEDLINE, Embase, CINAHL and the Cochrane Central Register of Controlled Trials. Eligible articles describing a perfusion measurement technique, used in a peri-procedural setting before and within 24 hours after the revascularisation procedure, with the aim of determining the effect of intervention in patients with PAD, were assessed for inclusion. The QUADAS-2 tool was used to assess the risk of bias and applicability of the studies.

RESULTS

An overview of 10 techniques found in 26 eligible articles focused on study protocols, research goals, and clinical outcomes is provided. Non-invasive techniques included laser speckle contrast imaging, micro-lightguide spectrophotometry, magnetic resonance imaging perfusion, near infrared spectroscopy, skin perfusion pressure, and plantar thermography. Invasive techniques included two dimensional perfusion angiography, contrast enhanced ultrasound, computed tomography perfusion imaging, and indocyanine green angiography. The results of the 26 eligible studies, which were mostly of poor quality according to QUADAS-2, were without exception, not sufficient to substantiate implementation in daily clinical practice.

CONCLUSION

This systematic review provides an overview of 10 tissue perfusion assessment techniques for patients with PAD. It seems too early to appoint one of them as a reference standard. The scope of future research in this domain should therefore focus on clinical accuracy, reliability, and validation of the techniques.

Contemporary outcomes of concomitant suprainguinal bypass with infrainguinal revascularization procedures in patients with chronic limb-threatening ischemia

OBJECTIVE

Combined suprainguinal and infrainguinal revascularization is sometimes necessary in the treatment of patients with chronic limb-threatening ischemia (CLTI). However, data on outcomes of concomitant revascularization procedures are lacking. We studied the outcomes of patients with CLTI who underwent suprainguinal bypass (SIB) alone, SIB with concomitant infrainguinal bypass (IIB), and SIB with concomitant infrainguinal peripheral endovascular intervention (IIPVI).

METHODS

We reviewed all patients in the Vascular Quality Initiative with CLTI who underwent SIB from January 2010 to June 2020. Logistic regression, Kaplan-Meier survival estimates, log-rank tests, and Cox regression were used to analyze outcomes. Outcomes were 30-day mortality, perioperative myocardial infarction, perioperative major amputation, 1-year amputation-free survival, and 5-year survival.

RESULTS

Of 8037 patients included, 81.3% (n = 6537) underwent SIB alone, 9.7% (n = 783) underwent SIB+IIB, and 8.9% (n = 717) underwent SIB+IIPVI. The indication for surgery was rest pain in 5040 (62.5%) and tissue loss in 3031 (37.6%). There were no significant differences in 30-day mortality and perioperative myocardial infarction rates. However, there was 2.8-fold increased odds of perioperative major amputation in both SIB+IIPVI (odds ratio [OR], 2.76; 95% confidence interval [CI], 1.30-5.88; P = .008) and SIB+IIB (OR, 2.79; 95% CI, 1.38-5.54; P = .004) among patients with rest pain as compared with SIB alone. Comparing SIB+IIPVI with SIB alone, there were no significant differences in 1-year freedom from amputation and amputation-free survival. SIB+IIPVI was associated with a 27% increased risk of 5-year mortality (hazard ratio [HR], 1.27; 95% CI, 1.03-1.55; P = .035). Compared with SIB alone, SIB+IIB was associated with 97% increased risk of 1-year major amputation among patients with rest pain (HR, 1.97; 95% CI, 1.06-3.69; P = .033), but a 47% decreased risk of 1-year major amputation or death for patients with tissue loss (HR, 0.53; 95% CI, 0.37-0.78; P = .001). SIB+IIPVI, compared with SIB+IIB, was associated with a two-fold increased risk of 1-year major amputation or death (HR, 2.04; 95% CI, 1.04-2.23), P = .003) and a 52% increased risk of 5-year mortality (HR,1.52; 95% CI, 1.04-2.24; P = .032) among patients with tissue loss.

CONCLUSIONS

This study shows that SIB with concomitant infrainguinal revascularization in patients with rest pain is associated with an increased risk of amputation, whereas SIB+IIB in patients with tissue loss is associated with decreased risk of amputation or death. SIB+IIB outperformed SIB+IIPVI in patients with tissue loss. SIB with infrainguinal revascularization should be limited in patients with rest pain in line with current guidelines, but SIB+IIB may be preferred in patients with tissue loss.

[Ischemia-reperfusion syndrome]

The ischemia-reperfusion syndrome complicates the course of a number of emergency conditions in various fields of clinical medicine, determines the course, prognosis and outcome of the disease. This review examines various aspects of the etiology, pathogenesis, and clinical manifestations of this syndrome. Particular attention is paid to its prevention and treatment. It is indicated that most of the studies devoted to this problem are of an experimental nature. The use of preparations based on succinic acid in the clinic is seen as the most promising direction in solving this issue.

Availability of interventional-radiological revascularization procedures in Germany - an analysis of the DeGIR Registry Data 2018/19

PURPOSE

 Peripheral artery disease (PAD) is a common condition with high socio-economic relevance. Therefore, qualified nationwide provision of interventional treatments of PAD is important for maintaining a high quality medical service in Germany.

MATERIALS AND METHODS

 All data on revascularization procedures from the quality management system of the German interventional radiological society (DeGIR) for the years 2018 and 2019 were retrospectively analysed. Number and distribution of DeGIR certified endovascular specialists and treatment centres was mapped. Documented procedures were broken down to the level of administrative districts. Absolute number of revascularization procedures and normalized number per one million inhabitants were computed.

RESULTS

 In 2019 there were 57 732 revascularization procedures from 228 participating centres performed by DeGIR certified interventional radiologists. A median of 62 recanalization procedures were documented per centre. 36 centres were considered to be high volume centres, with more than 500 procedures each. On a regional level in the years 2018 and 2019 combined a median (range) of 2324 (323-12 518) revascularization procedures per administrative district were performed by DeGIR certified interventional radiologist.

CONCLUSION

 There is a comprehensive nationwide high quality interventional-radiology service for the provision of revascularization procedures available in Germany.

KEY POINTS

  · In Germany there is a nationwide comprehensive infratsructure for the interventional-radiological treatment of PAD. · The volume of interventional-radiological treatments for PAD is growing. · There is a sufficient number of training and treatment centres for the delivery of interventional radiology procedures.

CITATION FORMAT

· Mahnken AH, Nadjiri J, Schachtner B et al. Availability of interventional-radiological revascularization procedures in Germany - an analysis of the DeGIR Registry Data 2018/19. Fortschr Röntgenstr 2021; DOI: 10.1055/a-1535-2774.

Maggot debridement therapy in critical limb ischaemia: a case study

OBJECTIVE

In critical limb ischaemia (CLI), first-line therapy is revascularisation, but alternative treatment options are needed in certain cases. Maggot debridement therapy (MDT) is historically considered to be contraindicated in ischaemic ulcers. Wound care in patients with CLI is becoming increasingly diverse with the development of novel revascularisation strategies; therefore, CLI now needs to be reconsidered as an indication for MDT.

METHOD

We retrospectively reviewed five legs with CLI (five male, one female) treated with MDT between January 2013 and December 2017. Changes in skin perfusion pressure (SPP) around the ulcer before and after MDT were evaluated. One or two cycles of MDT were performed (eight in total). We also evaluated the proportion of necrotic tissue in the ulcer and the presence of exposed necrotic bone. The proportion of necrotic tissue in the ulcer was classified as NT 1+ (<25%), NT 2+ (25-50%), NT 3+ (50-75%) or NT 4+ (>75%).

RESULTS

When the proportion of necrotic tissue was >50%, with no exposed necrotic bone in the wound, an increase in SPP was observed after five (62.5%) of eight cycles of MDT. And with a proportion of necrotic tissue of <25% and/or exposed necrotic bone in the wound, a decrease in SPP was observed after three (37.5%) of eight cycles. Wound healing was accelerated in the presence of increased SPP.

CONCLUSION

Effective MDT with increased SPP requires an ulcerative state of necrotic tissue grade > NT 3+, with no exposed necrotic bone.

PROMISE I early feasibility study of the LimFlow System for percutaneous deep vein arterialization in no-option chronic limb-threatening ischemia 12-month results

OBJECTIVE

We report the 6 and 12-month outcomes of the PROMISE I early feasibility study (EFS) after treatment of no-option chronic limb-threatening ischemia (CLTI) with percutaneous deep vein arterialization (pDVA) using the LimFlow System.

METHODS

Thirty-two no-option CLTI patients, previously offered major amputation, were enrolled in this single-arm EFS of the LimFlow pDVA System. No-option CLTI was defined as being ineligible for surgical or endovascular arterial revascularization. Patients were assessed for clinical status, pain, wound healing, and duplex ultrasound at 30 days, 6 months, and 12 months post-treatment. Primary endpoint analysis was amputation-free survival (AFS) at 30 days and 6 and 12 months. AFS was defined as freedom from above-ankle amputation of the index limb and freedom from all-cause mortality. Secondary endpoints evaluated included technical success of the procedure, and wound healing at 6 and 12 months.

RESULTS

Of 32 enrolled patients, 31 (97%) were successfully treated with the LimFlow System at the time of the procedure, and 2 (6.3%) were lost to follow-up. The 30-day, 6-month, and 12-month AFS rates were 91%, 74%, and 70% respectively. Wound healing status of fully healed or healing was 67% at 6-months, and 75% at 12-months. Reintervention was performed in 16 patients (52%) with 14 (88%) of the maintenance reinterventions occurring within the first three months. The majority of reinterventions, 12 (75%), involved the arterial inflow tract proximal to the stented LimFlow circuit, and no in-stent stenoses were determined to have been the cause of reintervention.

CONCLUSIONS

The LimFlow pDVA System was utilized in treating no-option patients with CLTI. High technical success rate was observed, with a significant percentage of patients surviving free of major amputation at 12 months. These results suggest early safety and provide an initial assessment of the efficacy of the LimFlow pDVA System which supports the expansion of carefully executed studies to determine whether this is a viable option that can be used in this critically disadvantaged and growing patient population.

Hydrogel-based therapeutic angiogenesis: An alternative treatment strategy for critical limb ischemia

Critical limb ischemia (CLI) is the most severe clinical manifestation of peripheral arterial disease (PAD), resulting in the total or partial loss of limb function. Although the conventional treatment strategy of CLI (e.g., medical treatment and surgery) can improve blood perfusion and restore limb function, many patients are unsuitable for these strategies and they still face the threats of amputation or death. Therapeutic angiogenesis, as a potential solution for these problems, attempts to manipulate blood vessel growth in vivo for augment perfusion without the help of extra pharmaceutics and surgery. With the rise of interdisciplinary research, regenerative medicine strategies provide new possibilities for treating many clinical diseases. Hydrogel, as an excellent biocompatibility material, is an ideal candidate for delivering bioactive molecules and cells for therapeutic angiogenesis. Besides, hydrogel could precisely deliver, control release, and keep the bioactivity of cargos, making hydrogel-based therapeutic angiogenesis a new strategy for CLI therapy. In this review, we comprehensively discuss the approaches of hydrogel-based strategy for CLI treatment as well as their challenges, and future directions.

Three-Year Outcomes From the LIBERTY 360 Study of Endovascular Interventions for Peripheral Artery Disease Stratified by Rutherford Category

Purpose:

To report the 3-year results of the LIBERTY 360 study, which investigated outcomes of endovascular treatment of symptomatic peripheral artery disease (PAD).

Materials and Methods:

The LIBERTY trial ( ClinicalTrials.gov identifier NCT01855412) was a prospective, observational, core laboratory–assessed, multicenter study of endovascular interventions enrolling >1200 participants treated at 51 sites. Data from 1189 patients were stratified according to Rutherford category (RC) and analyzed [RC 2-3 (n=500), RC 4-5 (n=589), and RC 6 (n=100)]. The primary outcomes were major amputation of the target limb and all-cause death; secondary outcomes were target vessel revascularization (TVR) or target lesion revascularization (TLR); major adverse events (MAEs; death within 30 days, TVR or TLR, and major amputation); death or major amputation combined; and change in self-reported quality of life (QoL) measures (VascuQol-25). The Kaplan-Meier (KM) method was employed to estimate the outcomes; estimates are presented with the 95% confidence intervals (CI). Predictors of 3-year MAE, death, TVR, and major amputation were analyzed using Cox proportional hazard regression modeling.

Results:

The 36-month KM survival rates were 86.0% in RC 2-3, 79.8% in RC 4-5, and 62.0% in RC 6 groups. The KM estimates of freedom from major amputation at 36 months were 98.5% in RC 2-3, 94.0% in RC 4-5, and 79.9% in RC 6. The 36-month KM estimates for freedom from TVR/TLR were 71.1% in RC 2-3, 64.2% in RC 4-5 and 61.9% in RC 6 groups. Patients with claudication at baseline were at lower risk for MAEs compared with RC 4-5 and RC 6 patients during the 36-month follow-up. Vascular QoL improved from baseline and persisted up to 36 months in all patients.

Conclusion:

Endovascular therapy is a viable treatment option for patients with symptomatic PAD, with sustained improved quality of life in both claudicants and patients with chronic limb-threatening ischemia. These results provide important point estimates for midterm outcomes after modern endovascular interventions for PAD.

The Role of Circulating Biomarkers in Peripheral Arterial Disease

Peripheral arterial disease (PAD) of the lower extremities is a chronic illness predominantly of atherosclerotic aetiology, associated to traditional cardiovascular (CV) risk factors. It is one of the most prevalent CV conditions worldwide in subjects >65 years, estimated to increase greatly with the aging of the population, becoming a severe socioeconomic problem in the future. The narrowing and thrombotic occlusion of the lower limb arteries impairs the walking function as the disease progresses, increasing the risk of CV events (myocardial infarction and stroke), amputation and death. Despite its poor prognosis, PAD patients are scarcely identified until the disease is advanced, highlighting the need for reliable biomarkers for PAD patient stratification, that might also contribute to define more personalized medical treatments. In this review, we will discuss the usefulness of inflammatory molecules, matrix metalloproteinases (MMPs), and cardiac damage markers, as well as novel components of the liquid biopsy, extracellular vesicles (EVs), and non-coding RNAs for lower limb PAD identification, stratification, and outcome assessment. We will also explore the potential of machine learning methods to build prediction models to refine PAD assessment. In this line, the usefulness of multimarker approaches to evaluate this complex multifactorial disease will be also discussed.

Post-exercise pulsatility index indicates treatment effects in peripheral arterial occlusive disease (PAOD)

Background

Hypothesis: Post-exercise measurements better discriminate PAOD-patients from healthy persons and they more sensitively detect hemodynamic improvements after treatment procedures than resting measurements.

Methods

A total of 19 healthy volunteers and 23 consecutive PAOD-patients underwent measurements of peak systolic velocity (PSV), end-diastolic velocity (EDV), minimal diastolic velocity (MDV), time-averaged maximum velocities (TAMAX), resistance index (RI) and pulsatility index (PI) before and after a standard exercise test (at 1, 2, 3, 4 and 5 min) before and after treatment (incl. epidemiological data, PAOD risk factors and comorbidities).

Results

In resting values, healthy persons and PAOD-patients did not differ significantly in any of the hemodynamic parameters. PSV increased after treatment in PAOD-patients by 5 cm/s (paired t‑test, p: 0.025); however, when the amplitude of autoregulatory changes related to the resting values were calculated, PAOD-patients showed clearly less hemodynamic changes after exercise than healthy persons (p: 0.04; 0.002; <0.001 for PSV, TAMAX and PI, resp.). The time course after exercise was compared by repeated measures of ANOVA. Healthy persons differed significantly in PI, RI and PSV from PAOD patients before and after treatment (p<0.001 each). The PAOD-patients revealed a significantly improved PI after treatment (p: 0.042). The only factor contributing significantly to PI independently from grouping was direct arterial vascularization as compared to discontinuous effects by an obstructed arterial tree.

Conclusion

Healthy persons cannot be well differentiated from PAOD-patients solely by hemodynamics at rest but by characteristic changes after standard exercise. Treatment effects are reflected by higher PI-values after exercise.

Current Status of Angiogenic Cell Therapy and Related Strategies Applied in Critical Limb Ischemia

Critical limb ischemia (CLI) constitutes the most severe form of peripheral arterial disease (PAD), it is characterized by progressive blockade of arterial vessels, commonly correlated to atherosclerosis. Currently, revascularization strategies (bypass grafting, angioplasty) remain the first option for CLI patients, although less than 45% of them are eligible for surgical intervention mainly due to associated comorbidities. Moreover, patients usually require amputation in the short-term. Angiogenic cell therapy has arisen as a promising alternative for these "no-option" patients, with many studies demonstrating the potential of stem cells to enhance revascularization by promoting vessel formation and blood flow recovery in ischemic tissues. Herein, we provide an overview of studies focused on the use of angiogenic cell therapies in CLI in the last years, from approaches testing different cell types in animal/pre-clinical models of CLI, to the clinical trials currently under evaluation. Furthermore, recent alternatives related to stem cell therapies such as the use of secretomes, exosomes, or even microRNA, will be also described.

Impact of impaired ambulatory capacity on the outcomes of peripheral vascular interventions among patients with chronic limb-threating ischemia

OBJECTIVE

Despite prior literature recommending against limb salvage in patients with poor functional status such as nonambulatory patients with chronic limb-threatening ischemia (CLTI), peripheral endovascular interventions continue to be carried out in this group of patients. Clinical outcomes following these interventions are, however, not well-characterized.

METHODS

A retrospective review was conducted on all patients treated for CLTI in the Vascular Quality Initiative from September 2016 to December 2019. Logistic regression, Kaplan-Meier survival estimates, log-rank tests, and Cox regression analyses were used as appropriate to study outcomes. The primary outcomes were 30-day mortality and 1-year amputation-free survival. The secondary outcomes were in-hospital death, postoperative complications, 1-year freedom from major amputation, and 2-year survival.

RESULTS

Of the 49,807 patients studied, 28,469 (57.2%) were ambulatory, 15,148 (31.0%) were ambulatory with assistance, 5395 (10.8%) were wheelchair bound, and 525 (1.1%) were bedridden. There was a 2-fold increase in the odds of 30-day death in patients who were ambulatory with assistance (odds ratio [OR], 2.03; 95% confidence interval [CI], 1.77-2.34; P < .001) and wheelchair-bound patients (OR, 2.09; 95% CI, 1.74-2.51; P < .001), and a more than 6-fold increase in bedridden patients (OR, 6.28; 95% CI, 4.55-8.65; P < .001) compared with ambulatory patients. There was a significantly higher odds of postoperative complications in patients who were ambulatory with assistance or bedridden, but no difference with wheelchair-bound patients. Among ambulatory patients, the risks of major amputation and death within 1 year were only 10% and 12%, respectively, whereas that of bedridden patients were as high as 30% and 38%, respectively. A stepwise decrease in amputation-free survival from 81% with full ambulatory capacity to less than 50% (47.7%) in bedridden patients was observed. The risk of major amputation or death within 1 year was 35% higher for ambulatory with assistance (hazard ratio [HR], 1.35; 95% CI, 1.26-1.44; P < .001), 65% higher for wheelchair-bound (HR, 1.65; 95% CI, 1.51-1.79; P < .001) and 2.6-fold higher for bedridden (HR, 2.64; 95% CI, 2.17-3.21; P < .001) compared with ambulatory. A similar association was seen for 1-year freedom from major amputation and 2-year survival.

CONCLUSIONS

Ambulatory impairment in patients with CLTI is associated with a significant increase in 30-day mortality and significant decrease in amputation-free survival after peripheral endovascular intervention. Bedridden patients had a 6-fold increase in the 30-day death rate, whereas their amputation-free survival dropped to less than 50% at 1 year. These risks should be considered during shared decision-making regarding management options for nonambulatory patients with CLTI.

Vasoactive Biomarkers Associated With Long-Term Incidence of Symptomatic Peripheral Arterial Disease and Mortality

We evaluated if plasma biomarkers can predict incident peripheral arterial disease (PAD) and mortality in a longitudinal cohort study. Men (n = 3618) and women (n = 1542) were included in the Malmö Preventive Project and underwent analysis of: C-terminal endothelin-1 (CT-proET-1), N-Terminal prosomatostatin (NT-proSST), midregional proatrial natriuretic peptide (MR-proANP), procalcitonin (PCT), and copeptin. Participants were followed up for incident PAD and mortality until December 31, 2016. Median follow-up was 11.2 years (interquartile range 9.4-12.2). Cumulative incidence of PAD was 4.3% (221/5160), 4.5% in men (164/3618) and 3.7% in women (57/1542; P = .174). In an adjusted Cox proportional hazards regression model, higher CT-proET-1 (hazard ratio [HR] 1.8; 95% confidence interval [CI] 1.4-2.3), NT-proSST (HR 1.5; 95% CI 1.2-2.0), and MR-proANP (HR 1.7; 95% CI 1.3-2.3) were independently associated with incident PAD, and higher CT-proET-1 (HR 1.3; 95% CI 1.2-1.5), NT-proSST (HR 1.2; 95% CI 1.1-1.3), MR-proANP (HR 1.4; 95% CI 1.3-1.6), PCT (HR 1.1; 95% CI 1.0-1.2), and copeptin (HR 1.2; 95% CI 1.1-1.4) were independently associated with mortality. Increased levels of CT-proET-1, NT-proSST, and MR-proANP were independently associated with incident PAD, whereas all the vasoactive biomarkers were independently associated with mortality during follow-up.

Outcomes of open and hybrid treatments in below the knee pathology for critical limb threatening ischemia

INTRODUCTION

The optimal management of below the knee pathology remains one of the most challenging areas for revascularization in patients presenting with critical limb threatening ischemia. Patients commonly have multilevel lesions and have a high amputation rate and associated mortality. This review aimed to assess the outcomes of below the knee revascularization strategies.

EVIDENCE ACQUISITION

An online literature search of medical databases for original articles or review articles was conducted using mesh terms.

EVIDENCE SYNTHESIS

Bypass surgery remains the gold standard for revascularization with good long-term outcomes with regards to patency, limb salvage, and quality of life but is associated with a higher morbidity than the endovascular approach. Given the increasing frailty of our patients, endovascular treatments have become the preferred strategy with results that are now equal to bypass. Hybrid surgery is an increasingly popular option as it combines the benefits of both endovascular and open surgery and although the evidence base is small the outcomes are encouraging.

CONCLUSIONS

Hybrid surgery offers promising results and could be considered in the treatment of multi-level lower limb arterial disease especially in high-risk patients or those who are not suitable for either open or endovascular techniques as a sole treatment modality.

[Results of comprehensive conservative treatment of patients with no-option chronic limb-threatening ischaemia]

AIM

The study was aimed at comparing efficacy of conventional conservative therapy and comprehensive treatment including a plasmid VEGF-165-gene therapy drug in 'no-option' chronic limb-threatening ischaemia with different prevalence of trophic ulcers and infection during a 1-year follow-up period.

PATIENTS AND METHODS

A total of 101 patients (54% being men and 46% women, mean age 69 years) with 'no-option' chronic limb-threatening ischaemia underwent comprehensive conservative treatment. They were subdivided into 4 groups according to the WIFI classification: WIFI 130 (n=38), 131 (n=23), 230 (n=16), 231 (n=24). The control group patients (n=58) received standard treatment using a PGE1 analogue (Vasaprostan) and the study group patients (n=43) underwent standard conservative treatment (SCT) in combination with gene therapy. The end points of the study were as follows: major amputation rate, amputation-free survival, total mortality, and ulcer healing rate during a 1-year of follow up.

RESULTS

Major amputation rate in the control and study groups amounted to 35 and 28% (p=0.48), respectively, with amputation-free survival of 53 and 63% (p=0.35), total mortality of 21 and 12% (p=0.23), ulcer healing rate of 31 and 51% (p=0.04), respectively. The WIfI classification made it possible to single out a subgroup of patients (WIfI combination 130) yielding other statistically significant results: major amputation rate 27% and 0% (p=0.03), amputation-free survival 59 and 94% (p=0.025), ulcer healing rate 50 and 88% (p=0.016), respectively.

CONCLUSION

Using plasmid-based VEGF-165 gene therapy in the subgroup with the WIfI combination 130 decreases the major amputation rate (p=0.03), increases amputation-free survival (p=0.025) and promotes ulcer healing (p=0.016) compared with the standard therapy during 1-year follow up. No significant differences in the compared groups were revealed by all endpoints of the study for other combinations analysed. The total mortality rate in patients with limb-threatening ischaemia does not depend on either the initial severity of ulcer or the selcted methods of conservative treatment.

Two-year Outcome of Quality of Life and Health Status for the Elderly with Chronic Limb-threatening Ischemia

Purpose

In elderly patients with chronic limb-threatening ischemia (CLTI), there is little scientific understanding of the long-term changes of quality of life (QoL) and health status (HS) after treatment. The primary goal of this study was to provide long-term QoL and HS results for elderly CLTI patients after therapy. Treatments consisted of endovascular revascularization, surgical revascularization, or conservative treatment. Furthermore, the aim of this study was to identify the distinctive trajectories of QoL and HS.

Patients and Methods

CLTI patients aged ≥70 years were included in a prospective observational cohort study with a two-year follow-up. The WHOQOL-BREF was used to asses QoL. The 12-Item Short Form Health Survey was used to measure HS. The QoL and HS scores were compared to the scores in the general elderly Dutch population. Latent class trajectory analysis was used.

Results

A total of 195 patients were included in this study. After two years, in all treatment groups patients showed significantly higher physical QoL score compared to baseline and there was no significant difference with the corresponding values in the elderly Dutch population. In the latent class trajectory analysis, there were no overlapping risk factors for poorer QoL or HS.

Conclusion

This study shows that QoL levels in surviving elderly CLTI patients in the long-term do not differ from the corresponding values for elderly in the general population. There were no disparities in sociodemographic, clinical and treatment characteristics associated with poorer QoL and HS. This study was carried out to encourage further analysis of the influence of biopsychosocial characteristics on QoL and HS in elderly CLTI patients.

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.

Heterogeneity of Age and Its Associated Features in Patients with Critical Limb Ischemia

Aim: Critical limb ischemia (CLI) has a wide age distribution. We aimed here to reveal age-associated clinical features in CLI patients.

Materials and Methods: We analyzed 531 Japanese CLI patients referred to vascular centers. The three-year mortality risk by age was compared to that for the Japanese nationals, derived from Japan’s national life table data. Clinical characteristics associated with age in CLI patients were also explored.

Results: Mean age was 73±10 years. Whereas 27.9% were aged ≥80 years, 19.2% were aged <65 years. Mortality risk was increased with age, but its risk ratio relative to the same-aged nationals was higher in younger patients. Incidence of major amputation was higher in a younger population. Receiving welfare, smoking, increased body mass index, diabetes with hemoglobin A1c ≥7.0%, non-high density lipoprotein cholesterol ≥190 mg/dL, renal failure, and the Wound, Ischemia, and foot Infection classification stage 4 were associated with younger age, whereas non-ambulation and institutionalization were associated with older age.

Conclusion: Patients aged <65 years, belonging to the working-age population, reached almost one fifth of the CLI population. Younger patients had a lower mortality risk in the population, but had a higher risk ratio relative to the same-aged nationals. Socioeconomic disadvantage, poor cardiovascular risk control, and wound severity were associated with younger age.

Clinical Outcomes Following Lower Extremity Vein Bypass for Chronic Limb Threatening Ischaemia (CLTI) at the University of Colombo, Sri Lanka

OBJECTIVE

Although high quality epidemiological data are lacking, the global increase in chronic limb threatening ischaemia may be disproportionately affecting low and LMICs. All available data for outcomes from bypass for limb salvage are from high income countries, with none from LMIC settings where the challenge is greatest. This study aimed to assess the clinical outcomes following vein lower extremity bypass for chronic limb threatening ischaemia at the University of Colombo, Sri Lanka, and to compare patients and outcomes with those described in the Society for Vascular Surgery (SVS) Objective Performance Goals (OPG) and United States National Surgical Quality Improvement Program (NSQIP).

METHODS

Consecutive patients (n = 367) undergoing SVS-OPG eligible lower extremity bypass between 2015 and 2017 were studied. Thirty day major adverse cardiovascular events (MACE), major adverse limb events (MALE), deaths, and amputations are reported, along with one year overall survival, limb salvage, and amputation free survival.

RESULTS

Patients at University of Colombo had more diabetes mellitus (80% vs. SVS 57% vs. NSQIP 50%, p < .001) and tissue loss (100% vs. SVS 74% vs. NSQIP 59%, p < .001). The 30 day MALE was 7.6%, which is not a statistically significant difference from the SVS (6.1%) or NSQIP (9%). The 30 day MACE was 8.2%, statistically significantly higher than NSQIP (4.2%, p < .001) but not SVS (6.2%, p = .20). At 12 months, the overall survival (82%) was within the OPG threshold, but limb salvage (81.8%) and amputation free survival (64.5%) were just outside.

CONCLUSION

Outcomes following vein bypass for ischaemic necrosis at the University of Colombo, Sri Lanka, are acceptable and similar to those reported from high income countries despite greater limb threat severity and resource limitations. Further real world data from similar settings on outcomes following revascularisation are required. These data suggest that a vein bypass first strategy for advanced ischaemic necrosis is feasible and effective even in resource limited settings.

Efficacy of nonviral gene transfer of human hepatocyte growth factor (HGF) against ischemic-reperfusion nerve injury in rats

Ischemic neuropathy is common in subjects with critical limb ischemia, frequently causing chronic neuropathic pain. However, neuropathic pain caused by ischemia is hard to control despite the restoration of an adequate blood flow. Here, we used a rat model of ischemic-reperfusion nerve injury (IRI) to investigate possible effects of hepatocyte growth factor (HGF) against ischemic neuropathy. Hemagglutinating virus of Japan (HVJ) liposomes containing plasmids encoded with HGF was delivered into the peripheral nervous system by retrograde axonal transport following its repeated injections into the tibialis anterior muscle in the right hindlimb. First HGF gene transfer was done immediately after IRI, and repeated at 1, 2 and 3 weeks later. Rats with IRI exhibited pronounced mechanical allodynia and thermal hyperalgesia, decreased blood flow and skin temperature, and lowered thresholds of plantar stimuli in the hind paw. These were all significantly improved by HGF gene transfer, as also were sciatic nerve conduction velocity and muscle action potential amplitudes. Histologically, HGF gene transfer resulted in a significant increase of endoneurial microvessels in sciatic and tibial nerves and promoted nerve regeneration which were confirmed by morphometric analysis. Neovascularization was observed in the contralateral side of peripheral nerves as well. In addition, IRI elevated mRNA levels of P2X3 and P2Y1 receptors, and transient receptor potential vanilloid receptor subtype 1 (TRPV1) in sciatic nerves, dorsal root ganglia and spinal cord, and these elevated levels were inhibited by HGF gene transfer. In conclusion, HGF gene transfer is a potent candidate for treatment of acute ischemic neuropathy caused by reperfusion injury, because of robust angiogenesis and enhanced nerve regeneration.

Current opinion on the role of the foot perfusion in limb amputation risk assessment

The most important and consulted guidelines dealing with not healing foot ulcers suggest the measurement of the foot perfusion (FP) to exclude the critical limb ischemia (CLI), because of the high risk of limb amputation. But the recommended cut-off values of FP fail to include all the heterogeneity of patients of the real-life with a not healing ulcer. Often these patients are diabetics with a moderate PAD but with a high level of infection. To meet this goal, in 2014, the Society for Vascular Surgery has published the "Lower Extremity Threatened Limb Classification System: Risk stratification based on Wound, Infection, and foot Ischemia (WIfI)." This new classification system has changed the criteria of assessment of limb amputation risk, replacing the single cut-off value role with a combination of a spectrum of perfusion values along with graded infection and dimension levels of skin ulcers. The impact of this new classification system was remarkable so to propose the substitution of the CLI definition, with the new Critical limb-threatening ischemia (CLTI), that seems to define the limb amputation risk more realistically.

Sex-Related Differences in the Outcomes of Endovascular Interventions for Chronic Limb-Threatening Ischemia: Results from the LIBERTY 360 Study

INTRODUCTION

Previous studies have suggested that women with chroniclimb-threatening ischemia (CLTI) may have worse outcomes than men. The aim of this study was to determine whether there are sex-related differences in outcomes of patients with CLTI undergoing endovascular treatment with current endovascular technologies.

PATIENTS AND METHODS

Data were derived from the LIBERTY 360 study (NCT01855412). Hazard ratios and the respective 95% confidence intervals were synthesized to examine the association between sex and all-cause mortality, target vessel revascularization (TVR), major amputation, major adverse event (MAE) and major amputation/death up to 3 years of follow-up.

RESULTS

A total of 689 patients with CLTI (female: N=252 vs male: N=437) treated with any FDA approved or cleared device were included. The mean lesion length was 126.9±117.3mm and 127.4±113.3mm for the female and male patients, respectively. Although a slightly higher incidence of in-hospital mortality was observed in the female group (1.2% vs 0.0%, p=0.049), there was no difference in female vs male survival rates during follow-up. However, the risk of major amputation at 18 months was higher for the male group (male vs female: HR: 2.36; 95% CI: 1.09-5.12; p=0.030). No difference between the two groups was detected in terms of TVR or MAE during follow-up.

DISCUSSION

Data regarding sex-related disparity in outcomes after endovascular therapy of patients with CLTI are conflicting. Gender-related characteristics rather than biological sex characteristics might be the cause of these conflicting findings. Further studies are needed to evaluate the role of sex in revascularization outcomes among this high-risk population.

Three-Year Outcomes of Orbital Atherectomy for the Endovascular Treatment of Infrainguinal Claudication or Chronic Limb-Threatening Ischemia

Purpose: To investigate the outcomes of orbital atherectomy (OA) for the treatment of patients with peripheral artery disease (PAD) manifesting as claudication or chronic limb-threatening ischemia (CLTI). Materials and Methods: The database from the LIBERTY study (ClinicalTrials.gov identifier NCT01855412) was interrogated to identify 503 PAD patients treated with any commercially available endovascular devices and adjunctive OA for 617 femoropopliteal and/or infrapopliteal lesions. Cox regression analyses were employed to examine the association between baseline Rutherford category (RC) stratified as RC 2-3 (n=214), RC 4-5 (n=233), or RC 6 (n=56) and all-cause mortality, target vessel revascularization (TVR), major amputation, major adverse event (MAE), and major amputation/death at up to 3 years of follow-up. The mean lesion lengths were 78.7±73.7, 131.4±119.0, and 95.2±83.9 mm, respectively, for the 3 groups. Results: After OA, balloon angioplasty was used in >98% of cases, with bailout stenting necessary in 2.0%, 2.8%, and 0% of the RC groups, respectively. A small proportion (10.8%) of patients developed angiographic complications, without differences based on presentation. During the 3-year follow-up, claudicants were at lower risk for MAE, death, and major amputation/death than patients with CLTI. The 3-year Kaplan-Meier survival estimates were 84.6% for the RC 2-3 group, 76.2% for the RC 4-5 group, and 63.7% for the RC 6 group. The 3-year freedom from major amputation was estimated as 100%, 95.3%, and 88.6%, respectively. Among CLTI patients only, the RC at baseline was correlated with the combined outcome of major amputation/death, whereas RC classification did not affect TVR, MAE, major amputation, or death rates. Conclusion: Peripheral artery angioplasty with adjunctive OA in patients with CLTI or claudication is safe and associated with low major amputation rates after 3 years of follow-up. These results demonstrate the utility of OA for patients across the spectrum of PAD.

[Lower-limb peripheral arterial disease]

Peripheral arterial disease is a result of atheroma. This disease is frequent in subjects with vascular risk factors. This disease is also frequent in low income countries. The detection and the diagnosis of peripheral arterial disease is obtained by calculating the ankle brachial index. Patients with peripheral arterial disease are not always symptomatic thus explaining how this disease is under diagnosed. The symptoms can be absent, and especially in case of diabetes or in women. In case of peripheral arterial disease, atheroma often involves other arterial vascular networks especially the coronaries. An adapted treatment reduces the morbi-mortality linked to this disease. This treatment is based on the correction of the vascular risk factors and especially tobacco cessation, walking rehabilitation and drugs (antiplatelet agent, statin, renin angiotensin system blocker). In case of rest or critic ischemia, the first-line treatment is a revascularisation. In peripheral arterial disease, management of patients is often non optimal and therapeutic targets fairly often obtained.

Comparative 12-Month Outcomes of Drug-Coated Balloon Versus Non-Drug-Coated Balloon Revascularization Strategy in Chronic Limb-Threatening Ischemia: Results From the XLPAD Registry

BACKGROUND

Endovascular therapy is often the preferred first treatment option for chronic limb threatening ischemia (CLTI) patients. Drug coated balloons (DCB) reduce restenosis rates compared to percutaneous transluminal angioplasty (PTA), however DCB use has not been studied systematically in patients with CLTI. Thus, the optimal treatment option for these complex lesions remains controversial.

METHODS

We report on 327 patients with CLTI treated either with DCB (n = 105) or non-DCB (n = 222) for femoropopliteal disease. Data were retrieved from the Excellence in Peripheral Artery Disease (XLPAD) registry (NCT01904851). Two DCB types were used at the discretion of the operator: Lutonix® (BARD Peripheral Vascular, Inc., Tempe, AZ, USA) and IN.PACT AdmiralTM (Medtronic, Santa Rosa, CA, USA). Odds ratios and the respective 95% confidence interval were synthesized to examine the association between the two groups in terms of all-cause mortality, target limb repeat endovascular or surgical revascularization, target vessel revascularization (TVR), major and minor amputation at 12 months of follow up.

RESULTS

The mean lesion length was 150.0 mm (SD:123.2) and 151.2 mm (SD:108.3) for the DCB and non-DCB group respectively. No difference between the two groups was detected in terms of all-cause mortality (2.86%vs2.7%,p = .94), target limb repeat endovascular or surgical revascularization (16.19%vs12.61%,p = .25), TVR (16.19%vs.11.71%,p = .26) or minor amputation (15.24%vs10.81%,p = .25) at 12 months of follow up. Although a higher incidence of 12 months major amputation was observed in the DCB group (11%vs.4%,p = .01), after adjusting for several risk factors the odds of major amputation were not statistically different between the DCB and non-DCB groups (OR:1.54;95%CI:0.53-4.51;p = .43).

CONCLUSIONS

Both DCB and non-DCB strategies are effective modalities for revascularization of patients with CLTI. No differences were identified between the DCB and non-DCB group in terms of late outcomes during 12 months of follow up.

Current opinions about the definition of critical limb ischemia: A debate still open after three decades

Critical limb ischemia (CLI) is the most advanced stage of peripheral arterial disease. It is clinically defined as rest pain with or without skin ulcer or gangrene and carries a very poor prognosis with a high rates of limb amputation and cardiovascular mortality. Despite the first definition of CLI has been published more than 30 years ago, the debate about what it really is, is still open. Over the years the hemodynamic parameters utilised to define the critical level of limb perfusion have changed. This has raised some question about the apparent confusion about the definition of CLI. Moreover, a new term such as "limb threatening ischemia" has replaced the definition of CLI in recent guideline. Therefore, it becomes necessary to understand the evolution of the concept and the definition of CLI, to interpret the future trend.Hence, this work analysing the guideline documents on peripheral arterial disease that have defined the CLI to date, aims to clarify the path that has brought to the current conceptual changes of the definition of CLI.

Laser Doppler blood flowmeter as a useful instrument for the early detection of lower extremity peripheral arterial disease in hemodialysis patients: an observational study

BACKGROUND

A simpler method for detecting atherosclerosis obliterans is required in the clinical setting. Laser Doppler flowmetry (LDF) is easy to perform and can accurately detect deterioration in skin perfusion. We performed LDF for hemodialysis patients to determine the correlations between blood flow in the lower limbs and peripheral arterial disease (PAD).

METHODS

This retrospective study included 128 hemodialysis patients. Patients were categorized into the non-PAD group (n = 106) and PAD group (n = 22), 14 early stage PAD patients were included in the PAD group. We conducted LDF for the plantar area and dorsal area of the foot and examined skin perfusion pressure (SPP) during dialysis.

RESULTS

SPP-Dorsal Area values were 82.1 ± 22.0 mmHg in the non-PAD, and 59.1 ± 20.3 mmHg in PAD group, respectively (p < 0.05). The LDF-Plantar blood flow (Qb) values were 32.7 ± 15.5 mL/min in non-PAD group and 21.5 ± 11.3 mL/min in PAD group (p < 0.001). A total of 21 non-PAD patients underwent LDF before and during dialysis. The LDF-Plantar-Qb values were 36.5 ± 17.6 mL/min before dialysis and 29.6 ± 17.7 mL/min after dialysis (p < 0.05). We adjusted SPP and LDF for PAD using logistic regression, SPP-Dorsal-Area and LDF-P were significantly correlated with PAD (p < 0.05). The receiver-operating characteristic curve analysis indicated cut-off values of 20.0 mL/min for LDF-Plantar-Qb during dialysis.

CONCLUSION

LDF is a simple technique for sensitive detection of early-stage PAD. This assessment will help physicians identify early-stage PAD, including Fontaine stage II in clinical practice, thereby allowing prompt treatment.

Cost-Effectiveness of Drug-Eluting Stents for Infrapopliteal Lesions in Patients with Critical Limb Ischemia: The PADI Trial

PURPOSE

Drug-eluting stents (DES) improve clinical and morphological long-term results compared to percutaneous transluminal angioplasty (PTA) with bailout bare metal stenting (BMS) in patients with critical limb ischemia (CLI) and infrapopliteal lesions (PADI trial). We performed a cost-effectiveness analysis of DES compared to PTA ± BMS in cooperation with Dutch health insurance company VGZ, using data from the PADI trial.

MATERIALS AND METHODS

In the PADI trial, adults with CLI (Rutherford category ≥ 4) and infrapopliteal lesions were randomized to receive DES with paclitaxel or PTA ± BMS. Seventy-four limbs (73 patients) were treated with DES and 66 limbs (64 patients) with PTA ± BMS. The costs were calculated by using the mean costs per stent multiplied by the mean number of stents used per patient (€750 × 1.8 for DES vs €250 × 0.3 for PTA ± BMS). These costs were compared with the costs of major amputation (€16.000) and rehabilitation (first year €15.750, second year €7.375 and third year €3.600).

RESULTS

The 5-year major amputation rate was lower in the DES group (19.3% vs 34.0% for PTA ± BMS; p = 0.091). In addition, the 5-year amputation-free survival and event-free survival were significantly higher in the DES group (31.8% vs 20.4%, p=0.043; and 26.2% vs 15.3%, p=0.041, respectively). After 1 year, the cost difference per patient between DES and PTA ± BMS is €1.679 in favor of DES and €2.694 after 3 years.

CONCLUSION

In our analysis, DES are cost-effective due to the higher hospital costs of amputation and rehabilitation in the PTA ± BMS group.

LEVEL OF EVIDENCE

Level 1b, analysis based on clinically sensible costs and randomized controlled trial.

Comparison of Cryopreserved Arterial Allografts Versus Heparin-bonded Vascular Grafts in Infragenicular Bypass for Chronic Limb Threatening Ischemia

BACKGROUND

The purpose of this study was to compare cryopreserved arterial allograft (CAA) to heparin-bonded prosthesis (HBP) in infragenicular bypasses for patients with chronic limb-threatening ischemia (CLTI).

METHODS

This retrospective study took place in 2 university hospitals and included 41 consecutive patients treated for CLTI. In the absence of a suitable saphenous vein, an infragenicular bypass was performed using either CAA (24 cases) or HBP (17 cases). Kaplan-Meyer analysis compared primary and secondary patency and amputation-free survival rates. Binomial logistic regression analyzed risk factors for major amputation and thrombosis.

RESULTS

The mean followup was 18.5 months (±14.3) in the CAA group, 17.6 (±6.1) in the HBP group. In the CAA group, primary and secondary patency rates at 12 months were 52% (±10.6) and 61% (±10.3), compared to 88% (±7.8) and 94% (±5.7) in the HBP group, respectively. The difference in patency rates was not statistically different (P = 0.27 and P = 0.28, respectively). The statistically significant factors of graft thrombosis were, a stage 4 from the WIfI classification (Wound Ischemia foot Infection) with a 6 times higher risk (P = 0.04), and a distal anastomosis on a leg artery with a 9 times higher risk of thrombosis (P = 0.03). Amputation-free survival rates at 18 months were similar between the groups (CCA: 75% (±9) versus HBP: 94% (±6), P = 0.11). Patients classified as WIfI stage 4 had 13 times higher odds to undergo major amputation than patients with WIfI stage 2 or 3 (95% CI, 1.16-160.93; P = 0.04). The intervention was longer in the CCA group of 74 min (278 min ± 86) compared to the HBP group (203 min ± 69). This difference was statistically significant (95% CI, 17.86-132.98), t(35) = 2.671, P = 0.01.

CONCLUSIONS

CCA is not superior to HBP in infragenicular bypasses for CLTI, and may not be worth the extra cost and the longer operative duration.

Using the epidemiology of critical limb ischemia to estimate the number of patients amenable to endovascular therapy

Critical limb ischemia represents the advanced stage of peripheral artery disease, a health problem with increasing prevalence. Critical limb ischemia is associated with significant mortality, limb loss, pain, and diminished health-related quality of life. Public awareness and early diagnosis are necessary for an effective treatment with early risk factor modification, smoking cessation, and exercise therapy. Herein, we present an overview of the epidemiology as well as the clinical stages of the disease, and estimate that there are 6.5 million patients with critical limb ischemia in the US, Europe, and Japan based on global population-based studies. At least 75% of these patients, accounting for approximately 4.8 million patients, are amenable to endovascular therapy.

Validation of randomized controlled trial-derived models for the prediction of postintervention outcomes in chronic limb-threatening ischemia

BACKGROUND

Chronic limb-threatening ischemia (CLTI) represents the most severe form of peripheral artery disease and has a large impact on quality of life, morbidity, and mortality. Interventions are aimed at improving tissue perfusion and averting amputation and secondary cardiovascular complications with an optimal risk-benefit ratio. Several prediction models regarding postprocedural outcomes in CLTI patients have been developed on the basis of randomized controlled trials to improve clinical decision-making. We aimed to determine model performance in predicting clinical outcomes in selected CLTI cohorts.

METHODS

This study validated the Bypass versus Angioplasty in Severe Ischaemia of the Leg (BASIL), Finland National Vascular registry (FINNVASC), and Prevention of Infrainguinal Vein Graft Failure (PREVENT III) models in data sets from a peripheral artery disease registry study (Athero-Express) and two randomized controlled trials of CLTI in The Netherlands, Rejuvenating Endothelial Progenitor Cells via Transcutaneous Intra-arterial Supplementation (JUVENTAS) and Percutaneous Transluminal Angioplasty and Drug-eluting Stents for Infrapopliteal Lesions in Critical Limb Ischemia (PADI). Receiver operating characteristic (ROC) curve analysis was used to calculate their predictive capacity. The primary outcome was amputation-free survival (AFS); secondary outcomes were all-cause mortality and amputation at 12 months after intervention.

RESULTS

The BASIL and PREVENT III models showed predictive values regarding postintervention mortality in the JUVENTAS cohort with an area under the ROC curve (AUC) of 81% and 70%, respectively. Prediction of AFS was poor to fair (AUC, 0.60-0.71) for all models in each population, with the highest predictive value of 71% for the BASIL model in the JUVENTAS population. The FINNVASC model showed the highest predictive value regarding amputation risk in the PADI population with AUC of 78% at 12 months.

CONCLUSIONS

In general, all models performed poor to fair in predicting mortality and amputation. Because the BASIL model performed best in predicting AFS, we propose use of the BASIL model to aid in the clinical decision-making process in CLTI. However, improvements in performance have to be made for any of these models to be of real additional value in clinical practice.

Leg ischaemia management collaboration (LIMb): study protocol for a prospective cohort study at a single UK centre

INTRODUCTION

Severe limb ischaemia (SLI) is the end stage of peripheral arterial occlusive disease where the viability of the limb is threatened. Around 25% of patients with SLI will ultimately require a major lower limb amputation, which has a substantial adverse impact on quality of life. A newly established rapid-access vascular limb salvage clinic and modern revascularisation techniques may reduce amputation rate. The aim of this study was to investigate the 12-month amputation rate in a contemporary cohort of patients and compare this to a historical cohort. Secondary aims are to investigate the use of frailty and cognitive assessments, and cardiac MRI in risk-stratifying patients with SLI undergoing intervention and establish a biobank for future biomarker analyses.

METHODS AND ANALYSIS

This single-centre prospective cohort study will recruit patients aged 18-110 years presenting with SLI. Those undergoing intervention will be eligible to undergo additional venepuncture (for biomarker analysis) and/or cardiac MRI. Those aged ≥65 years and undergoing intervention will also be eligible to undergo additional frailty and cognitive assessments. Follow-up will be at 12 and 24 months and subsequently via data linkage with NHS Digital to 10 years postrecruitment. Those undergoing cardiac MRI and/or frailty assessments will receive additional follow-up during the first 12 months to investigate for perioperative myocardial infarction and frailty-related outcomes, respectively. A sample size of 420 patients will be required to detect a 10% reduction in amputation rate in comparison to a similar sized historical cohort, with 90% power and 5% type I error rate. Statistical analysis of this comparison will be by adjusted and unadjusted logistic regression analyses.

ETHICS AND DISSEMINATION

Ethical approval for this study has been granted by the UK National Research Ethics Service (19/LO/0132). Results will be disseminated to participants via scientific meetings, peer-reviewed medical journals and social media.

TRIAL REGISTRATION NUMBER

NCT04027244.

Critical limb ischemia: Current and novel therapeutic strategies

Critical limb ischemia (CLI) is the advanced stage of peripheral artery disease spectrum and is defined by limb pain or impending limb loss because of compromised blood flow to the affected extremity. Current conventional therapies for CLI include amputation, bypass surgery, endovascular therapy, and pharmacological approaches. Although these conventional therapeutic strategies still remain as the mainstay of treatments for CLI, novel and promising therapeutic approaches such as proangiogenic gene/protein therapies and stem cell-based therapies have emerged to overcome, at least partially, the limitations and disadvantages of current conventional therapeutic approaches. Such novel CLI treatment options may become even more effective when other complementary approaches such as utilizing proper bioscaffolds are used to increase the survival and engraftment of delivered genes and stem cells. Therefore, herein, we address the benefits and disadvantages of current therapeutic strategies for CLI treatment and summarize the novel and promising therapeutic approaches for CLI treatment. Our analyses also suggest that these novel CLI therapeutic strategies show considerable advantages to be used when current conventional methods have failed for CLI treatment.

A Pro-Inflammatory Biomarker-Profile Predicts Amputation-Free Survival in Patients with Severe Limb Ischemia

Patients with Severe Limb Ischemia (SLI) have a high risk of amputation and mortality. Here, we investigated a panel of serum biomarkers with the aim of identifying biomarkers for major events and mechanisms that contribute to disease progression in established SLI. A panel of biomarkers including GROα, HGF, SCF, SCGFβ, SDF1α, TRAIL, IL-6, IL-8, FGFβ, GCSF, GMCSF, IP10, MCP1, PDGFbb, RANTES, TNFα, VEGF, sICAM, sVCAM, TM, and E-selectin was measured in serum samples from a subset (n = 108) of the JUVENTAS cohort. The primary outcome was major events, defined as major amputation or death. The inflammatory biomarkers IL-6, IL-8, GROα and IP-10 were significantly elevated in patients who reached a major endpoint. Results were validated in a secondary cohort (n = 146). Cox regression showed that adjusted hazard ratios were 1.40 (95% CI: 1.15-1.70, p = 0.0007) and 1.48 (95% CI 1.16-1.87, p = 0.001) for IL-6 and IP-10 in a fully adjusted model containing both biomarkers. A prediction model using IL-6 and IP-10 showed predictive accuracy with an AUC of ~ 78% in both discovery and validation cohorts, which is higher than previously published models. We conclude that inflammatory biomarkers predict major events in patients with SLI and allow the creation of biomarker-based risk-prediction models.