Percutaneous Therapies for Peripheral Artery Disease

Short-term therapeutic efficacy analysis of drug-coated balloon combined with chocolate balloon for the treatment of femoropopliteal artery lesions

Background

To report our experience of short-term results of drug-coated balloon (DCB) combined with chocolate balloon in the treatment of femoropopliteal artery lesions.

Methods

From June 2021 to December 2022, patients with femoropopliteal artery lesions (Rutherford classification 2-6) who underwent DCB combined with Chocolate PTA balloon catheter treatment were included. Clinical data of the patients were collected, and follow-up was conducted at 3, 6, and 12 months. The primary patency rate and the freedom from clinically-driven target lesion revascularization (f-TLR) rate were calculated by Kaplan-Meier survival curves.

Results

This study included a total of 43 patients (mean age 72.84 ± 10.19 years, male proportion 67.4%) with 47 lesions. Among them, 17 lesions (36.2%) presented severe stenosis with an average lesion length of 110.41 ± 47.67 mm. Thirty lesions (63.8%) were identified as chronic total occlusions (CTO), with an average occlusion length of 104.13 ± 61.12 mm. The Kaplan-Meier survival curve estimated a primary patency rate of 87.2% at 6 months and 78.7% at 12 months. The f-TLR rate at 12 months was 85.1%, estimated by Kaplan-Meier survival curve. The mean ankle-brachial index (ABI) increased from 0.53 ± 0.12 before the surgery to 0.87 ± 0.12 at 12 months postoperatively, and this difference was statistically significant (p < 0.001). A total of 91.5% of patients (43/47) showed a decrease in Rutherford classification at 12 months postoperatively. The proportion of patients with Rutherford class 4-6 decreased from 70.2% (33/47) preoperatively to 4.3% (2/47) at 12 months postoperatively, and this difference was statistically significant (p < 0.001). Among the limbs, 34 (72.3%) experienced dissection during the surgery, with 29 cases classified as type B or lower dissection and 5 cases classified as type C or higher (severe dissection) (10.6%). Two limbs (4.3%) required the use of salvage stents. There were no procedure- or device-related deaths within the 12-month period. Twelve limbs (25.5%) underwent minor amputations (toe amputations).

Conclusion

The combination of DCB and chocolate balloon angioplasty has achieved satisfactory patency rates and f-TLR results in 1-year follow-up for the treatment of femoropopliteal artery lesions. However, further confirmation of these findings is needed through multicenter data and long-term follow-up results.

Intravascular Ultrasound-Guided vs Angiography-Guided Drug-Coated Balloon Angioplasty in Patients With Complex Femoropopliteal Artery Disease

BACKGROUND

Intravascular ultrasound (IVUS) guidance has been shown to yield favorable outcomes for endovascular treatment of femoropopliteal artery (FPA) disease with drug-coated balloon (DCB) angioplasty. However, the specific benefits of IVUS for treatment of complex FPA lesions remain uncertain.

OBJECTIVES

In this study, the authors compared the clinical impact of IVUS-guided vs angiography-guided DCB angioplasty in patients with complex or noncomplex FPA lesions.

METHODS

This study was a prespecified, primary subgroup analysis of the randomized IVUS-DCB trial. Patients with FPA undergoing DCB angioplasty were randomized to receive the procedure under IVUS or angiography guidance. The primary endpoint was 12-month primary patency; secondary endpoints included clinically driven target lesion revascularization (CD-TLR), sustained clinical improvement, and hemodynamic improvement.

RESULTS

Among the 237 patients enrolled, 158 had complex FPA (Trans-Atlantic Inter-Society Consensus II [TASC II] type C/D), and 79 had noncomplex FPA (TASC II type A/B). In complex FPA, IVUS guidance was associated with significantly higher rates of primary patency (82.1% vs 60.3%; HR for loss of primary patency: 0.34; 95% CI: 0.16-0.70; P = 0.002), freedom from CD-TLR (90.0% vs 76.9%; HR: 0.31; 95% CI: 0.13-0.75; P = 0.01), and sustained clinical and hemodynamic improvement relative to angiography guidance. There was no significant difference in primary patency (87.5% vs 88.2%; HR: 1.84; 95% CI: 0.39-8.60; P = 0.44) or occurrence secondary endpoints between the IVUS-guidance and angiography-guidance groups for patients with noncomplex FPA.

CONCLUSIONS

In endovascular treatment of FPA using DCB, IVUS guidance was significantly associated with improved 12-month clinical outcomes, particularly in patients with complex FPA lesions. (Intravascular Ultrasound-Guided Drug-Coated Balloon Angioplasty for Femoropopliteal Artery Disease [IVUS-DCB] trial; NCT03517904).

Delivery of N-Cadherin Targeting Peptides to Vascular Tissues by Surface-Modified Polyurethane Nanoparticles via a Drug-Coated Balloon

Restenosis remains a long-standing limitation to effectively maintain functional blood flow after percutaneous transluminal angioplasty (PTA). While the use of drug-coated balloons (DCBs) containing antiproliferative drugs has improved patient outcomes, limited tissue transfer and poor therapeutic targeting capabilities contribute to off-target cytotoxicity, precluding adequate endothelial repair. In this work, a DCB system was designed and tested to achieve defined arterial delivery of an antirestenosis therapeutic candidate, cadherin-2 (N-cadherin) mimetic peptides (NCad), shown to selectively inhibit smooth muscle cell migration in vitro and limit intimal thickening in early animal PTA models. To enable successful tissue transfer in the current work, a nanoparticle excipient system previously demonstrated to be an effective carrier of NCad in vitro was integrated with customized DCB coating methodologies designed to prevent therapeutic loss during delivery. DCB design took into consideration four components: (1) the angioplasty balloon; (2) a poly(ethylene oxide) (PEO) monolayer acting as a hydrophilic spacer between the balloon surface and the nanoparticles to assist with improved nanoparticle release; (3) surface-modified degradable polar hydrophobic ionic polyurethane (D-PHI) nanoparticles loaded with NCad to facilitate the transport of the therapeutic peptide into vascular tissue; and (4) a PEO sacrificial coating applied over the nanoparticle excipient layer to prevent premature losses during transit to the artery. The nanoparticle-DCB platform successfully delivered NCad to rat carotid tissue, with superior efficacy and increased permeation within the vessel wall compared with soluble NCad infusion alone. Nanoscale technologies in conjunction with enhanced DCB design properties hold promise in advancing the localized delivery of preventive restenosis therapies in vascular disease.

Platelet Membrane-Encapsulated Poly(lactic-co-glycolic acid) Nanoparticles Loaded with Sildenafil for Targeted Therapy of Vein Graft Intimal Hyperplasia

Autologous vein grafts have attracted widespread attention for their high transplantation success rate and low risk of immune rejection. However, this technique is limited by the postoperative neointimal hyperplasia, recurrent stenosis and vein graft occlusion. Hence, we propose the platelet membrane-coated Poly(lactic-co-glycolic acid) (PLGA) containing sildenafil (PPS). Platelet membrane (PM) is characterised by actively targeting damaged blood vessels. The PPS can effectively target the vein grafts and then slowly release sildenafil to treat intimal hyperplasia in the vein grafts, thereby preventing the progression of vein graft restenosis. PPS effectively inhibits the proliferation and migration of vascular smooth muscle cell (VSMCs) and promotes the migration and vascularisation of human umbilical vein endothelial cells (HUVECs). In a New Zealand rabbit model of intimal hyperplasia in vein grafts, the PPS significantly suppressed vascular stenosis and intimal hyperplasia at 14 and 28 days after surgery. Thus, PPS represents a nanomedicine with therapeutic potential for treating intimal hyperplasia of vein grafts.

A Retrospective Comparative Study of Mid-Term Outcomes of Atherectomy, Drug-Coating Balloon Angioplasty, and Plain Old Balloon Angioplasty for Isolated Atherosclerotic Popliteal Artery Lesions

We retrospectively reviewed the clinical data of 217 consecutive Chinese patients with isolated atherosclerotic popliteal artery lesions treated with atherectomy technique, DCB, and plain old balloon angioplasty from August 2017 to August 2022. There was no difference in the 48-month patency rate between the atherectomy, DCB, and POBA groups (65%, 56%, and 51%, respectively; p = 0.3), as well as in adjusted Cox regression. Similarly, no difference was observed in the 48-month clinically driven target lesion revascularization-free (CDTLR-free) rate among the groups (77%, 74%, and 65%; p = 0.34), confirmed by adjusted Cox regression. In the 48 months, a significant difference was observed in amputation-free rates between the atherectomy, DCB, and POBA groups (97%, 91%, and 83%, respectively; p < 0.05). Adjusted Cox regression indicated POBA had worse outcomes than DCB and atherectomy. In the stenosis and occlusion subgroup, the 48-month primary patency rates were 65%, 70%, and 54% (p > 0.9) and 65% versus 49% versus 49% (p = 0.3), showing no differences among the three groups. In the short lesion subgroup (<10 cm), the 48-month primary patency rates were 65%, 66%, and 61% for atherectomy, DCB, and POBA, respectively (p = 0.7). In the long lesion subgroup (≥10 cm), the 48-month patency rates were higher in the atherectomy and DCB groups compared to POBA (64%, 44%, and 34%), with no significant difference among the groups (p = 0.13). DCB and atherectomy demonstrate improved short- and mid-term clinical outcomes compared to POBA in Chinese patients with popliteal artery disease.

Symptom Descriptors in Individuals Living With Undiagnosed Lower Extremity Peripheral Artery Disease

OBJECTIVE

Most individuals with lower extremity peripheral artery disease (PAD) experience symptoms other than claudication and live with undiagnosed PAD yet no tools exist to detect atypical PAD symptoms. The purpose of this study was to identify discriminating PAD symptom descriptors from a community-based sample of patients with no current diagnosis of PAD.

METHODS

Symptoms descriptors were obtained in a sample of 22 participants with persistent lower extremity symptoms pre/post exercise. An ankle brachial index with exercise was used to classify participants as "PAD" or "No PAD."

RESULTS

Thirteen (59%) participants had a positive ankle brachial index (<0.9, ≥20% drop postexercise, or 30 mmHg drop postexercise). Symptoms do not disappear while walking, trouble keeping up with friends/family, positive response to pain or discomfort while sitting, and pain outside of the calves and thighs were associated with a positive ankle brachial index.

CONCLUSION

Atypical symptoms were common among study participants. Symptoms while sitting and symptoms outside of the calf and thigh were negatively associated with a positive ankle brachial index. More precise descriptions of symptom characteristics are needed to improve PAD symptom recognition.

Manufacturing, Processing, and Characterization of Self-Expanding Metallic Stents: A Comprehensive Review

This paper aims to review the State of the Art in metal self-expanding stents made from nitinol (NiTi), showing shape memory and superelastic behaviors, to identify the challenges and the opportunities for improving patient outcomes. A significant contribution of this paper is its extensive coverage of multidisciplinary aspects, including design, simulation, materials development, manufacturing, bio/hemocompatibility, biomechanics, biomimicry, patency, and testing methodologies. Additionally, the paper offers in-depth insights into the latest practices and emerging trends, with a special emphasis on the transformative potential of additive manufacturing techniques in the development of metal stents. By consolidating existing knowledge and highlighting areas for future innovation, this review provides a valuable roadmap for advancing nitinol stents.

The causal relationship between human blood metabolites and risk of peripheral artery disease: a Mendelian randomization study

Background

Peripheral Artery Disease (PAD) is a common vascular disorder typically caused by atherosclerosis, leading to impaired blood supply to the lower extremities, resulting in pain, necrosis, and even amputation. Despite extensive research into the pathogenesis of PAD, many mysteries remain, particularly regarding its association with human blood metabolites.

Methods

To explore the causal relationship between 1,400 serum metabolites and PAD, a two-sample Mendelian randomization (MR) analysis was conducted. The Inverse Variance-Weighted (IVW) method was the primary technique used to estimate the causal impact of the metabolites on PAD. To enhance the analysis, several additional methods were employed: MR-Egger regression, weighted median, simple mode, and weighted mode. These methods provided a comprehensive evaluation beyond the primary IVW estimation. To ensure the validity of the MR findings, sensitivity analysis was performed. Furthermore, a bidirectional MR approach was applied to explore the possibility of a reverse causal effect between PAD and potential candidate metabolites.

Results

After rigorous selection, significant associations were found between 1-(1-enyl-stearoyl)-2-arachidonoyl-GPE (p-18:0/20:4) and X-17653 levels with PAD. 1-(1-enyl-stearoyl)-2-arachidonoyl-GPE (p-18:0/20:4) was positively associated with increased PAD risk (IVW OR = 1.13, 95% CI, 1.06-1.21; P < 0.001). X-17653 levels were associated with decreased PAD risk (IVW OR = 0.88, 95% CI, 0.83-0.94; P < 0.001). In the reverse direction, PAD was positively associated with increased 1-(1-enyl-stearoyl)-2-arachidonoyl-GPE (p-18:0/20:4) levels (IVW OR = 1.16, 95% CI, 1.01-1.34; P = 0.036). PAD was not associated with X-17653.

Conclusion

Among 1,400 blood metabolites, 1-(1-enyl-stearoyl)-2-arachidonoyl-GPE (p-18:0/20:4) and X-17653 are significantly associated with PAD risk. Importantly, in the reverse direction, PAD was found to be positively associated with increased levels of 1-(1-enyl-stearoyl)-2-arachidonoyl-GPE (p-18:0/20:4). This highlights the bidirectional nature of the association and suggests a potential feedback mechanism between PAD and this specific lipid species. 1-(1-enyl-stearoyl)-2-arachidonoyl-GPE (p-18:0/20:4) may serve as potential biomarkers for PAD, aiding early diagnosis and providing novel avenues for personalized treatment and management. However, further validation and research are warranted despite the promising results.

Intravascular ultrasound-guided drug-coated balloon angioplasty for femoropopliteal artery disease: a clinical trial

BACKGROUND AND AIMS

Drug-coated balloons (DCBs) have demonstrated favourable outcomes following endovascular therapy for femoropopliteal artery (FPA) disease. However, uncertainty remains whether the use of intravascular ultrasound (IVUS) can improve the outcomes of DCBs.

METHODS

This prospective, multicentre, randomized trial, conducted at seven centres in South Korea, compared the outcomes of IVUS-guided vs. angiography-guided angioplasty for treating FPA disease with DCBs. Patients were assigned to receive IVUS-guided (n = 119) or angiography-guided (n = 118) angioplasty using DCBs. The primary endpoint was 12-month primary patency.

RESULTS

Between May 2016 and August 2022, 237 patients were enrolled and 204 (86.0%) completed the trial (median follow-up; 363 days). The IVUS guidance group showed significantly higher primary patency [83.8% vs. 70.1%; cumulative difference 19.6% (95% confidence interval 6.8 to 32.3); P = .01] and increased freedom from clinically driven target lesion revascularization [92.4% vs. 83.0%; difference 11.6% (95% confidence interval 3.1 to 20.1); P = .02], sustained clinical improvement (89.1% vs. 76.3%, P = .01), and haemodynamic improvement (82.4% vs. 66.9%, P = .01) at 12 months compared with the angiography guidance group. The IVUS group utilized larger balloon diameters and pressures for pre-dilation, more frequent post-dilation, and higher pressures for post-dilation, resulting in a greater post-procedural minimum lumen diameter (3.90 ± 0.59 vs. 3.71 ± 0.73 mm, P = .03).

CONCLUSIONS

Intravascular ultrasound guidance significantly improved the outcomes of DCBs for FPA disease in terms of primary patency, freedom from clinically driven target lesion revascularization, and sustained clinical and haemodynamic improvement at 12 months. These benefits may be attributed to IVUS-guided optimization of the lesion before and after DCB treatment.

Safety and effectiveness of the Phoenix atherectomy device for endovascular treatment of common femoral and popliteal arteries: Results of the EN-MOBILE trial

Background: This study aimed to assess the peri- and postprocedural outcomes of atherectomy-assisted endovascular treatment of the common femoral (CFA) and popliteal arteries. Methods: Phoenix atherectomy was used for the treatment of 73 and 53 de novo CFA and popliteal artery lesions, respectively, in 122 consecutive patients. Safety endpoints encompassed perforation and peripheral embolization. Postprocedural endpoints included freedom from clinically driven target lesion revascularization (CD-TLR) and clinical success (an improvement of ⩾ 2 Rutherford category [RC]). In addition, 531 patients treated for popliteal artery stenosis or occlusion without atherectomy were used as a comparator group. Results: Procedural success (residual stenosis < 30% after treatment) was 99.2%. The need for bail-out stenting was 2 (2.7%) and 3 (5.7%) in CFA and popliteal artery lesions, respectively. Only one (1.4%) embolization occurred in the CFA, which was treated by catheter aspiration. No perforations occurred. After 1.50 (IQR = 1.17-2.20) years, CD-TLR occurred in seven (9.2%) and six (14.6%) patients with CFA and popliteal artery lesions, respectively, whereas clinical success was achieved in 62 (91.2%) and 31 (75.6%), respectively. Patients treated with atherectomy and DCB in the popliteal artery after matching for baseline RC, lesion calcification, length, and the presence of chronic total occlusion, exhibited higher freedom from CD-TLR compared to the nondebulking group (HR = 3.1; 95% CI = 1.1-8.5, p = 0.03). Conclusion: Atherectomy can be used safely and is associated with low rates of bail-out stenting in CFA and popliteal arteries. CD-TLR and clinical success rates are clinically acceptable. In addition, for the popliteal artery, atherectomy combined with DCB demonstrates lower CD-TLR rates compared to a DCB alone strategy. (German Clinical Trials Register: DRKS00016708).

Impact of Chronic Kidney Disease on In-Hospital Outcomes of Hospitalizations With Acute Limb Ischemia Undergoing Endovascular Therapy

PURPOSE

Studies on outcomes related to endovascular treatment (EVT) in advanced stages of chronic kidney disease (CKD) and end-stage renal disease (ESRD) among hospitalizations with acute limb ischemia (ALI) are limited.

METHODS

The Nationwide Inpatient Sample was quarried from October 2015 to December 2017 to identify the hospitalizations with ALI and undergoing EVT. The study population was subdivided into 3 groups based on their CKD stages: group 1 (No CKD, stage I, stage II), group 2 (CKD stage III, stage IV), and group 3 (CKD stage V and ESRD). The primary outcome was all-cause in-hospital mortality.

RESULTS

A total of 51 995 hospitalizations with ALI undergoing EVT were identified. The in-hospital mortality was significantly higher in group 2 (OR = 1.17; 95% CI 1.04 - 1.32, p=0.009) and group 3 (OR = 3.18; 95% CI 2.74-3.69, p<0.0001) compared with group 1. Odds of minor amputation, vascular complication, atherectomy, and blood transfusion were higher among groups 2 and 3 compared with group 1. Group 2 had higher odds of access site hemorrhage compared with groups 1 and 3, whereas group 3 had higher odds of major amputation, postprocedural infection, and postoperative hemorrhage compared with groups 1 and 2. Besides, groups 2 and 3 had lower odds of discharge to home compared with group 1. Finally, the length of hospital stay and cost of care was significantly higher with the advancing CKD stages.

CONCLUSION

Advanced CKD stages and ESRD are associated with higher mortality, worse in-hospital outcomes and higher resource utilization among ALI hospitalizations undergoing EVT.

CLINICAL IMPACT

Current guidelines are not clear for the optimum first line treatment of acute limb ischemia, especially in patients with advanced kidney disease as compared to normal/mild kidney disease patients. We found that advanced kidney disease is a significant risk factor for worse in-hospital morbidity and mortality. Furthermore, patients with acute limb ischemia and advanced kidney disease is associated with significantly higher resource utilization as compared to patients with normal/mild kidney disease. This study suggests shared decision making between treating physician and patients when considering endovascular therapy for the treatment of acute limb ischemia in patients with advanced kidney disease.

Editor's Choice - Endovascular Versus Surgical Treatment for All Comer Patients With Prosthetic Bypass Graft Occlusion: The Multicentre ENSUPRO Study

OBJECTIVE

Bypass surgery plays a key role in complex lower limb lesions. However, there is a lack of evidence regarding the management of symptomatic prosthetic bypass graft (PBG) occlusion. This study aimed to report outcomes following open, hybrid, or endovascular management of patients presenting with symptomatic PBG occlusion.

METHODS

A multicentre, retrospective cohort study was conducted, including patients presenting with PBG occlusion between January 2014 and December 2021 from 18 centres. It assessed the comparative value of treatment strategies, including (1) recanalisation of native vessels, (2) endovascular treatment of the failed PBG, (3) hybrid treatment, and (4) open surgery. The primary outcome measure was amputation free survival (AFS, time to major amputation and or death), whereas all cause mortality, major amputation, PBG re-occlusion, target lesion revascularisation (TLR), and Rutherford category (RC) improvement during follow up were considered as secondary endpoints.

RESULTS

Of 260 patients with occluded PBGs, 108 (41.5%) were treated endovascularly (24 [22.2%] by recanalisation of native vessels and 84 [77.7%] by PBG re-opening), 57 (21.9%) underwent hybrid revascularisation, and 58 (22.3%) had surgery. In addition, 27 (10.4%) were treated conservatively and 10 (3.8%) received systemic thrombolysis. With a median follow up of 1.4 (0.6 - 3.0) years, AFS was 95.5%, 76.4%, 45.5%, and 37.1%, respectively in Groups 1 - 4 (p = .007). Older age and non-endovascular treatment (HR 1.05 and 1.70; p < .01 for both) were independent predictors of poor AFS. Endovascular treatment was associated with lower rates of major amputation (p = .04), PBG re-occlusion (p < .001), and TLR (p = .037), and higher RC improvements (p < .001), whereas all cause mortality was comparable between treatment groups (p = .21).

CONCLUSION

Endovascular treatment is associated with higher rates of AFS and RC improvement and lower rates of PBG re-occlusion and TLR in patients with PBG occlusion.

Investigator attitudes on equipoise and practice patterns in the BEST-CLI trial

OBJECTIVES

There has been significant variability in practice patterns and equipoise regarding treatment approach for chronic limb-threatening ischemia (CLTI). We aimed to assess treatment preferences of Best Endovascular vs Best Surgical Therapy in Patients with CLTI (BEST-CLI) investigators prior to and following the trial.

METHODS

An electronic 60-question survey was sent to 1180 BEST-CLI investigators in 2022, after trial conclusion and before announcement of results. Investigators' preferences were assessed across clinical scenarios for both open (OPEN) and endovascular (ENDO) revascularization strategies. Vascular surgeon (VS) surgical and ENDO preferences were compared with a 2010 survey administered to prospective investigators before trial funding.

RESULTS

For the 2022 survey, the response rate was 20.2% and was comprised of VSs (76.3%), interventional cardiologists (11.4%) and interventional radiologists (11.6%). The majority (72.6%) were in academic practice and 39.1% were in practice for >20 years. During initial CLTI work-up, 65.8%, 42.6%, and 55.9% of respondents always or usually ordered an arterial duplex, computed tomography angiography, and vein mapping, respectively. The most common practice distribution between ENDO and OPEN procedures was 70/30. Postoperatively, a majority reported performing routine duplex surveillance of vein bypass (99%), prosthetic bypass (81.9%), and ENDO interventions (86%). A minority reported always or usually using the wound, ischemia, and foot infection (WIfI) criteria (25.8%), GLASS (8.3%), and a risk calculator (14.8%). More than one-half (52.9%) agreed that the statement "no bridges are burned with an ENDO-first approach" was false. Intervention choice was influenced by availability of the operating room or ENDO suite, personal schedule, and personal skill set in 30.1%, 18.0%, and 45.9% of respondents, respectively. Most respondents reported routinely using paclitaxel-coated balloons (88.1%) and stents (67.5%); however, 73.3% altered practice when safety concerns were raised. Among surgeons, 17.8%, 2.9%, and 10.3% reported performing >10 annual alternative autogenous vein bypasses, composite vein composite vein bypasses, and bypasses to pedal targets, respectively. Among all interventionalists, 8%, 24%, and 8% reported performing >10 annual radial access procedures, pedal or tibial access procedures, and pedal loop revascularizations. The majority (89.1%) of respondents felt that CLTI teams improved care; however, only 23.2% had a defined team. The effectiveness of the teamwork at institutions was characterized as highly effective in 42.5%. When comparing responses by VSs to the 2010 survey, there were no changes in preferred treatment based on Inter-Society Consensus for the Management of Peripheral Arterial Disease (TASC) II classification or conduit preference. In 2022, OPEN surgery was preferred more for a popliteal occlusion. For clinical scenarios, there were no differences except a decreased proportion of respondents who felt there was equipoise for major tissue loss for major tissue loss (43.8% vs 31.2%) and increased ENDO choice for minor tissue loss (17.6% vs 30.8%) (P < .05).

CONCLUSIONS

There is a wide range of practice patterns among vascular specialists treating CLTI. The majority of investigators in BEST-CLI had experience in both advanced OPEN and ENDO techniques and represent a real-world sample of technical expertise. Over the course of the decade of the BEST-CLI trial, there was overall similar equipoise among VSs.

Application of a rehabilitation management strategy based on symptom management theory in postoperative functional exercises in patients with lower extremity arteriosclerosis obliterans

BACKGROUND

Lower extremity arteriosclerosis obliterans (ASO) is the most common occlusive disease of the peripheral blood vessels.

OBJECTIVE

To explore the application effect of symptom management-based rehabilitation strategy in postoperative functional exercises in patients with lower extremity ASO.

METHODS

The researchers selected 136 patients that underwent lower extremity ASO surgery for the first time in their department from January to September 2020. Patients were divided into a control group (n= 68) and an experimental group (n= 68). The control group implemented routine discharge rehabilitation education and continuous nursing. On this basis, the experimental group applied the symptom management theory to the rehabilitation management strategy to compare the degree of pain, the ankle-brachial index, self-care ability and quality of life between the two groups before and after the intervention.

RESULTS

Three months (P= 0.045) and six months (P=0.013) after discharge, the experimental group's degree of pain was significantly lower than that of the control group. At one month (P= 0.019), three months (P= 0.003) and six months (P= 0.000) after discharge, the experimental group recovered significantly better than the control group. At six months after discharge, the self-care ability, mood status and physical pain of the experimental group were significantly higher than in the control group (P< 0.05).

CONCLUSION

The rehabilitation management strategy, which is based on symptom management theory, can effectively improve the symptoms, quality of life and self-efficacy of ASO patients in continuous care. This nursing strategy is worthy of clinical promotion.

Outcomes of atherectomy in patients undergoing lower extremity revascularisation

BACKGROUND

There is a paucity of real-world data on the in-hospital (IH) and post-discharge outcomes in patients undergoing lower extremity peripheral vascular intervention (PVI) with adjunctive atherectomy.

AIMS

In this retrospective, registry-based study, we evaluated IH and post-discharge outcomes among patients undergoing PVI, treated with or without atherectomy, in the National Cardiovascular Data Registry PVI Registry.

METHODS

The IH composite endpoint included procedural complications, bleeding or thrombosis. The primary out-of-hospital endpoint was major amputation at 1 year. Secondary endpoints included repeat endovascular or surgical revascularisation and death. Multivariable regression was used to identify predictors of atherectomy use and its association with clinical endpoints.

RESULTS

A total of 30,847 patients underwent PVI from 2014 to 2019, including 10,971 (35.6%) treated with atherectomy. The unadjusted rate of the IH endpoint occurred in 524 (4.8%) of the procedures involving atherectomy and 1,041 (5.3%) of non-atherectomy procedures (p=0.07). After adjustment, the use of atherectomy was not associated with an increased risk of the combined IH endpoint (p=0.68). In the 6,889 (22.4%) patients with out-of-hospital data, atherectomy was associated with a reduced risk of amputation (adjusted hazard ratio [aHR] 0.67, 95% confidence interval [CI]: 0.51-0.85; p<0.01) and surgical revascularisation (aHR 0.63, 95% CI: 0.44-0.89; p=0.017), no difference in death rates (p=0.10), but an increased risk of endovascular revascularisation (aHR 1.21, 95% CI: 1.06-1.39; p<0.01) at 1 year.

CONCLUSIONS

The use of atherectomy during PVI is common and is not associated with an increase in IH adverse events. Longitudinally, patients treated with atherectomy undergo repeat endovascular reintervention more frequently but experience a reduced risk of amputation and surgical revascularisation.

How I do it: Pedal access and pedal loop revascularization for patients with chronic limb-threatening ischemia

An increasing proportion of patients with chronic limb-threatening ischemia are older and have multiple comorbidities, including diabetes and renal failure. For those who are not candidates for a surgical bypass, this set of patients presents a challenge to vascular surgeons and interventionalists owing to the complex below-the-knee and increasingly below-the-ankle disease pattern that can fail traditional approaches for endovascular intervention. Two techniques, the retrograde pedal access and the pedal-plantar loop technique, can be useful in these settings and in skilled hands can be used safely, with a high technical success rate. In patients with chronic limb-threatening ischemia who are not candidates for a single-segment saphenous vein bypass, the retrograde pedal access technique can be used not only in the setting of failed antegrade treatment, but also primarily when faced with a difficult groin or as an adjunct during a planned antegrade-retrograde intervention. The pedal plantar loop technique allows for retrograde access to tibial vessels without retrograde vessel puncture and additionally offers the ability to treat the pedal-plantar arch, which may have added benefit in wound healing. We describe the tips and tricks for these two techniques used in our limb salvage practice.

Drug-eluting, balloon-expandable, bioresorbable vascular scaffolds reduce neointimal thickness and stenosis in an animal model of percutaneous peripheral intervention

Objective

Recanalization with balloon angioplasty and/or self-expanding stents (SES) has become the endovascular treatment of choice for symptomatic femoropopliteal occlusive disease. These strategies generate suboptimal clinical results, however, because they fail to expand the artery fully and ineffectively prevent recoil, neointimal hyperplasia, and restenosis. Balloon-expandable stents, given their greater radial force and rigid structure, represent a more effective treatment strategy, but only short lengths can be implanted safely in arteries that deform and bend with skeletal motion. The purpose of this preclinical experiment was to test the hypothesis that simultaneous implantation of a series of short, resorbable, balloon-expandable, paclitaxel-eluting scaffolds would prevent neointimal hyperplasia and stenosis compared with SES in an animal model of percutaneous femoropopliteal intervention.

Methods

We extruded 6 × 60 mm Efemoral Vascular Scaffold Systems (EVSS) from copolymers of poly-L-lactic acid, coated with paclitaxel 3 μg/mm2, crimped onto a single delivery balloon, and implanted percutaneously into the iliofemoral arteries of eight Yucatan mini-swine. We implanted 7- to 8-mm × 60 mm SES into the contralateral experimental arteries. The animals were serially imaged with contrast angiography and optical coherence tomography after 30, 90, 180, 365, and 730 days. The primary end point of this study was neointimal morphometry over time. Secondary end points included acute deformation and angiographic and optical coherence tomography-derived measurements of chronic vascular response.

Results

Over the 2-year study period, one SES was found to be completely occluded at 90 days; all EVSS were widely patent at all time points. Arteries treated with SES exhibited profound neointimal hyperplasia with in-stent stenosis. In contrast, arteries treated with EVSS exhibited only modest vascular responses and minimal stenosis. After 2 years, the mean neointimal thickness (0.45 ± 0.12 vs 1.31 ± 0.91 mm; P < .05) and area (8.41 ± 3.35 vs 21.86 ± 7.37 mm2; P < .05) were significantly decreased after EVSS implantation. By 2 years, all scaffolds in all EVSS-treated arteries had resorbed fully.

Conclusions

In this preclinical animal model of peripheral endovascular intervention, the EVSS decreased neointimal hyperplasia and stenosis significantly compared with SES, then dissolved completely between the first and second years after implantation.

Analysis of Fatigue Strength and Reliability of Lower Limb Arterial Stent at Different Vascular Stenosis Rates and Stent-to-Artery Ratios

In order to study the influence of different vascular stenosis rates and stent-to-artery ratios on the fatigue strength and reliability of lower limb arterial stents, numerical simulation was conducted for the fatigue strength of complete SE stents under pulsating loads using a finite element method. Then, fracture mechanics and conditional probability theory were adopted for mathematical modeling, whereby analyzing the crack growth rate and reliability with stents of different thickness (0.12, 0.15, and 0.18 mm) at different vascular stenosis rates (30, 50, and 70%) and stent-to-artery ratios (80, 85, and 90%). The study found: all three stents of different thickness failed to meet 10-year service life at three vascular stenosis rates; all three stents of different thickness met 10-year service life at three stent-to-artery ratios. With increased vascular stenosis rate, the elastic strain of stents was increased, while the fatigue strength was decreased; with increased stent-to-artery ratio, the elastic strain of the stent was increased, while the reliability of the stent was reduced. After the stent with an initial crack was implanted into the vessel, the crack length underwent non-linear growth with increased pulsating cyclic loads. When the pulsating load reached 3 × 10⁸, the growth rate of the crack on the stent surface increased exponentially, leading to a rapid decrease in reliability. Vascular stenosis rate, stent release ratio, and support thickness have significant effects on crack length propagation rate and reliability. Determining the influence of vascular stenosis rate and stent-to-artery ratio on the fatigue strength and reliability of stents provides a valuable reference for evaluating the fracture failure rate and safety of stents.

One single drug-coated balloon for all shapes/diameters? Neointimal proliferation inhibition in porcine peripheral arteries

BACKGROUND

Long diseased vessel segments of peripheral arteries may display irregular shapes with different diameters. The aim of this study was to investigate inhibition of neointimal proliferation in porcine peripheral vessels with different diameters covered by one single hyper-compliant drug-coated balloon (HCDCB), compared to conventional drug-coated balloons (DCB), each selected according to the respective vessel diameter.

METHODS AND RESULTS

Neointimal proliferation was stimulated in proximal and distal segments of the peripheral arteries by balloon overstretch and stent implantation. Inhibition of neointimal proliferation by one single HCDCB was compared to two vessel diameter-adjusted DCB per artery and to one single uncoated hyper-compliant balloon (HCB). Sixteen HCB, 16 HCDCB, and 32 DCB were used in 16 arteries each. Quantitative angiography (QA), optical coherence tomography (OCT) and histology showed a similar anti-restenotic effect for one HCDCB compared to two vessel diameter-adjusted DCB in narrow distal and wider proximal segments (QA diameter stenosis: 18.7±12.3% vs. 22.8±15.5%, p = 0.535; OCT area stenosis: 21.4±11.6% vs. 23.6±12.3%, p = 0.850; histomorphometry diameter stenosis: 27.5±7.1% vs. 26.9±8.0%, p = 0.952) and indicated significant inhibition of neointimal proliferation by HCDCB vs. uncoated HCB (QA diameter stenosis: 18.7±12.3% vs. 30.3±16.7%, p = 0.008; OCT area stenosis: 21.4±11.6% vs. 34.7±16.0%, p = 0.004; histomorphometry diameter stenosis: 27.5±7.1% vs. 32.5±8.5%, p = 0.038).

CONCLUSIONS

HCDCB were found to be similar effective as DCB in inhibiting neointimal proliferation in vessel segments with different diameters. One single long HCDCB may allow for treatment of segments with variable diameters, and thus, replace the use of several vessel diameter-adjusted DCB.

Safety and Effectiveness of Endovascular Therapy for the Treatment of Peripheral Artery Disease in Patients with and without Diabetes Mellitus

This study investigated the distribution of risk factors, lesion characteristics and endovascular revascularization (EVR) strategies in patients with peripheral arterial disease (PAD) with vs without diabetes mellitus (DM). Data were collected within the RECcording COurses of vasculaR Diseases (RECCORD) registry. Demographic data, lesion localization (iliac vs femoropopliteal vs below-the-knee (BTK)) and lesion complexity score (LCS) based on number of affected segments, and lesion length (< 10 vs 10-20 vs > 20 cm), EVR strategies and peri-procedural complications were analysed in 786 patients with and 1337 without diabetes mellitus. Patients with diabetes mellitus were older (71.6 ± 9.6 vs 69.4 ± 10.5 years, P < .001) and had higher LCS and more often BTK lesions (P < .05 for all). Lesions were treated less frequently with stents (48.7 vs 59.6%, P < .001) in patients with diabetes mellitus, whereas a non-significant trend was noticed for higher DCB treatment rates (48.3 vs 44.4%, P = .07). Post-interventional ankle-brachial index (ABI) increase was similar (from .77 ± .28 to .92 ± .25 with diabetes mellitus and from .74 ± .21 to .90 ± .20 without diabetes mellitus, P < .001 for both). Peri-/post-procedural complications were low in both groups (4.6%). Patients with diabetes mellitus, who undergo endovascular revascularization are older, have more comorbidities and higher target lesion complexity. However, treatment success rates are similar and complication rates are low.

Predictors of Amputation-free Survival after Endovascular Intervention for Chronic Limb-Threatening Ischemia in the Modern era

BACKGROUND

Chronic limb-threatening (CLTI) is associated with 25% limb loss and 25% mortality at 1-year. Its lethality increases to 45% in patients subjected to a major amputation. Percutaneous peripheral intervention (PPI) constitutes an attractive and less morbid treatment option for patients with CLTI. The purpose of this study was to assess amputation-free survival (AFS) in a contemporary cohort treated with endovascular recanalization and assess its predictors.

METHODS

Patients with CLTI undergoing endovascular revascularization at a single regional hospital between 2015-2019 were reviewed. Baseline demographic characteristics, Wound, Ischemia, and foot Infection (WIfI) stage, technical details, and clinical outcomes were tabulated. The primary endpoint was AFS; a P-value < 0.05 was used for univariate screening and inclusion in a multivariable model.

RESULTS

A total of 137 limbs in 111 patients were studied. Comorbidities were prevalent and included diabetes (65%), congestive heart failure (21%), and dialysis dependence (18%). The majority of revascularized limbs presented with advanced wounds (66% WIfI stages 3-4; 47% Rutherford category 6). Presenting WIfI stages were similar across races (P = 0.26). Peripheral interventions most commonly targeted femoropopliteal disease (69%), although 26% were multilevel. Percutaneous atherectomy, stenting, and paclitaxel-coated or eluting devices were utilized in 68%, 28%, and 15% of cases, respectively. After a median follow-up of 16 months (interquartile range IQR = 4-29 months), significant independent predictors of reduced AFS included nonWhite race (HR = 2.96 [1.42-6.17]; P = 0.004) and WIfI stage 4 wounds (HR = 2.23 [1.10-4.52]; P = 0.026). At one year following successful revascularization, only 59% ± 1% of patients were alive with their limb intact.

CONCLUSIONS

Despite considerable and consistent advances in urban health care delivery and the techniques of PPI, CLTI remains a morbid and deadly disease. Even in the endovascular era, nearly half of all patients presenting with CLTI will lose their limb and/or life within the first year. Unfortunately, late-stage presentation continues to be commonplace. Although endovascular intervention can reliably restore patency to affected arteries, this appears insufficient to restore most patients to health.

pH/Thermosensitive dual-responsive hydrogel based sequential delivery for site-specific acute limb ischemia treatment

Acute limb ischemia (ALI) is the most severe manifestation of peripheral artery disease, accompanied by pH/temperature-microenvironment changes in two different phases. In the acute phase, temperature and pH are significantly decreased, and reactive oxygen species (ROS) are excessively generated owing to the sharp reduction of blood perfusion. Afterwards, in the chronic phase, although the temperature gradually recovers, angiogenesis is delayed due to chronic vascular injury, skeletal muscle cell apoptosis and endothelial cell dysfunction. Current therapeutic strategies mainly focus on recanalization; however, their effects on scavenging ROS in the acute phase and promoting angiogenesis in the chronic phase are quite limited. Herein, an injectable pH and temperature dual-responsive poloxamer 407 (PF127)/hydroxymethyl cellulose (HPMC)/sodium alginate (SA)-derived hydrogel (FHSgel), encapsulating melatonin and diallyl trisulfide-loaded biodegradable hollow mesoporous silica nanoparticles (DATS@dHMSNs), is developed, which can intelligently respond to the different phases of ALI. In the acute phase of ischemia, the decreased pH results in the rapid release of melatonin to scavenge excessive ischemia-induced ROS. On the other hand, in the chronic repair phase, the recovered temperature triggers the sustained release of DATS@dHMSNs from the FHSgel, thus generating hydrogen sulfide (H₂S) to enhance the angiogenesis and microcirculation reconstruction of ischemic limbs.

Prevalent use of high-intensity statin therapy and LDL-C target attainment among PAD patients undergoing angioplasty

Summary: Background: The global burden of peripheral arterial disease (PAD) is substantial. Reducing the major modifiable risk factors for noncommunicable disease, including dyslipidaemia, represents a public health priority. Aim is to evaluate the prevalent adequate use of lipid-lowering therapy (LLT) and low-density lipoprotein cholesterol (LDL-C) attainment among patients with PAD of the lower extremities undergoing percutaneous transluminal angioplasty. Patients and methods: We screened PAD patients treated at the University Hospital Zurich (January 2012–December 2018). We excluded patients <18 years, without classifiable severity of PAD, or with missing LDL-C or medication data. In this cross-sectional study, we studied the prevalent LLT use and LDL-C values in target according to the most recent European guidelines. Available clinical data included demographic information, lipid profile, type and dose of LLT, characteristics of the artery obstruction and angioplasty. Results: A total of 2,148 angioplasties were performed in 956 patients: 614 (64%) were men; the mean age was 70.6 (SD 11.4) years. A total of 608 (64%) had a non-critical PAD (Fontaine stage I–IIb), whereas the remaining had a critical limb ischemia or a diabetic foot syndrome. Their median LDL-C value was 2.00 (Q1–Q3: 1.50–2.60) mmol/L. In accordance to the 2016 and 2019 European Society of Cardiology guidelines, the LDL-C target of 1.8 and 1.4 mmol/L was not reached in 63% (n=599) and in 79% (n=760) of patients, respectively. Only 41% (n=390) of patients were on high-intensity statin therapy. Conclusions: The attainment of LDL-C targets, as recommended by current European guidelines, and the use of high-intensity LLT were unsatisfactory in the majority of PAD patients.

Multiphysical Analytical Modeling and Design of A Magnetically Steerable Robotic Catheter for Treatment of Peripheral Artery Disease

This article presents a unique multiphysical analytical modeling framework and solution algorithm to provide an effective tool for design of magnetically steerable robotic catheters (MSRCs) experiencing external interaction loads. Particularly, in this study, we are interested in design and fabrication of a MSRC with flexural patterns for treatment of peripheral artery disease (PAD). Aside from the parameters involved in the magnetic actuation system and the external interaction loads acting on the MSRC, the considered flexural patterns have a critical role on the deformation behavior and steerability of the proposed MSRC. Therefore, to optimally design such MSRC, we utilized the proposed multiphysical modeling approach and thoroughly evaluated the influence of involved parameters on the performance of the MSRC via two simulations studies. We also conducted experimental studies in a free bending condition and in the presence of different external interaction loads on two custom-designed MSRCs to thoroughly evaluate the efficacy of the proposed multiphysical model and solution algorithm. Our analysis demonstrates the accuracy of the proposed approach and necessity of utilizing such models to optimally design a MSRC before fabrication procedure.

Directional versus orbital atherectomy of femoropopliteal artery lesions: Angiographic and intravascular ultrasound outcomes

OBJECTIVES

The aim of this study was to compare the ability of two different atherectomy modalities, the directional atherectomy system (DAS) and the orbital atherectomy system (OAS), to modify plaque and augment luminal gain as evaluated by angiography and intravascular ultrasound (IVUS) in patients with symptomatic femoro-popliteal peripheral arterial disease (PAD).

BACKGROUND

Atherectomy is frequently utilized in the treatment of complex PAD. To date, there are no head-to-head comparisons of existing devices and their selection is based mostly on operator preference rather than on supportive data.

METHODS

This was a single-center, prospective, randomized trial designed to assess the impact of DAS in comparison to OAS on atherosclerotic plaque. Pre- and postatherectomy lesion characterization was performed by angiography and IVUS. Drug-coated balloon (DCB) angioplasty was performed after atherectomy with similar analysis repeated.

RESULTS

Sixty patients were randomized to undergo either DAS or OAS. Pretreatment angiographic and IVUS characteristics were similar in the DAS and OAS groups. DAS led to a greater reduction in plaque volume throughout the entire lesion (5.9% vs. 1.1%, p = 0.003). This corresponded to a greater increase in total vessel and lumen volume by IVUS (161.5 mm³ vs. 50.2 mm³ , p = 0.001; 178.6 mm³ vs. 47.0 mm³ , p = 0.004, respectively), as well as a reduction in angiographic stenosis (40% vs. 70%, p < 0.001). After DCB, 10 patients required stenting for suboptimal results in the OAS group compared with two in the DAS group (p = 0.021).

CONCLUSIONS

Compared to OAS, DAS demonstrated a greater plaque volume reduction and luminal gain with significantly fewer stents needed post-DCB.

Dual-Resonance (16/32 MHz) Piezoelectric Transducer With a Single Electrical Connection for Forward-Viewing Robotic Guidewire

Peripheral artery disease (PAD) affects more than 200 million people globally. Minimally invasive endovascular procedures can provide relief and salvage limbs while reducing injury rates and recovery times. Unfortunately, when a calcified chronic total occlusion is encountered, ~25% of endovascular procedures fail due to the inability to advance a guidewire using the view provided by fluoroscopy. To enable a sub-millimeter, robotically steerable guidewire to cross these occlusions, a novel single-element, dual-band transducer is developed that provides simultaneous multifrequency, forward-viewing imaging with high penetration depth and high spatial resolution while requiring only a single electrical connection. The design, fabrication, and acoustic characterization of this device are described, and proof-of-concept imaging is demonstrated in an ex vivo porcine artery after integration with a robotically steered guidewire. Measured center frequencies of the developed transducer were 16 and 32 MHz, with -6 dB fractional bandwidths of 73% and 23%, respectively. When imaging a 0.2-mm wire target at a depth of 5 mm, measured -6 dB target widths were 0.498 ± 0.02 and 0.268 ± 0.01 mm for images formed at 16 and 32 MHz, respectively. Measured SNR values were 33.3 and 21.3 dB, respectively. The 3-D images of the ex vivo artery demonstrate high penetration for visualizing vessel morphology at 16 MHz and ability to resolve small features close to the transducer at 32 MHz. Using images acquired simultaneously at both frequencies as part of an integrated forward-viewing, guidewire-based imaging system, an interventionalist could visualize the best path for advancing the guidewire to improve outcomes for patients with PAD.

Role of Doppler Ultrasound and Percutaneous Transluminal Angioplasty in Early Diagnosis and Management of Peripheral Artery Disease

BACKGROUND: Peripheral arterial disease (PAD) denotes vascular disorder which peripheral artery’s obstruction or constriction is found. PAD with diabetic history is more susceptible to ischemic ulcer than PAD with no diabetic. The presence of Diabetes mellitus (DM) in PAD can speed up 4 times greater risk of developing Critical Limb Ischemia. In our hospital, difficulty performing extremity perfusion assessment is often found because those examinations are not available, so possibility of PAD can be missed. Therefore, optimalization use of Doppler Ultrasound (DUS) is important in our case. AIM: The purpose of our case writing is to give information about substantial parameter of DUS in determine presence of PAD and define the role of percutaneous transluminal angioplasty (PTA) in PAD. The earlier PAD discovered, faster further treatment conducted, especially PTA. CASE REPORT: A 65-year-old female patient with intermittent left calf pain for 7 months who went to internal medicine outpatient has reported. She has history of type 2 DM and significant hyperlipidemia. On physical examination, vital signs revealed normal value. Body mass index was 28 kg/m2. Resting ankle-brachial index (ABI) measurement was 1.14 and 1.12 at the right and left dorsalis pedis, respectively. DUS showed spectral narrow, reversal flow and no clear spectral window in superficial femoral artery. There are clear spectral window, spectral narrow, and reversal flow in poplitea artery. No clear spectral window, no spectral narrow, and no reversal flow in anterior tibia artery. Clear spectral window, reversal flow, and no spectral narrow are appear in posterior tibia artery. Arteriogram of left inferior extremity showed middle part partial stenosis of anterior tibia artery. Dilatation with standard balloon for 1 min was done. After that, no stenosis in same location and she wasn’t feel calf pain again. CONCLUSION: Compared with two other parameters, reversal flow in DUS is most important parameter to establish presence of stenosis. PTA is adequate to give revascularization stenosis in PAD.

Subintimal Versus Intraluminal Approach for Femoropopliteal Chronic Total Occlusions Treated With Intravascular Ultrasound Guidance

Background

The subintimal approach (SA) is widely used in endovascular therapy for femoropopliteal chronic total occlusion lesions. However, when compared with the intraluminal approach (IA), the safety and efficacy of SA in real‐world practice are not well characterized. Furthermore, there is a paucity of data on the clinical impact of subintimal and intraluminal wire passage (SWP and IWP, respectively) assessed by intravascular ultrasound.

Methods and Results

From the IVORY (Intravascular Ultrasound‐Supported Endovascular Therapy in Superficial Femoral Artery) registry, this study included 500 patients undergoing endovascular therapy for femoropopliteal chronic total occlusion lesions (SA, n=67; IA, n=433; and SWP, n=186; IWP, n=314). The primary end point was the cumulative 1‐year incidence of restenosis. The rate of perioperative complications was also assessed. Propensity score matching analysis was performed to adjust for the intergroup differences. After propensity score matching, the final study population consisted of 59 pairs (SA, n=59; IA, n=348) and 170 pairs (SWP, n=170; IWP, n=293), respectively. Cumulative 1‐year incidence of restenosis was comparable between the SA and IA groups (41.0% versus 43.4%, P=0.40). No significant difference in 1‐year restenosis rate between the SWP and IWP groups was observed (48.2% versus 40.8%, P=0.40), although the SWP group tended to be a higher rate of perioperative complications than the IWP group (8.2% versus 4.1%, P=0.07).

Conclusions

At 1 year, both SA and IA showed acceptable results for femoropopliteal chronic total occlusion lesions. Cumulative 1‐year incidence of restenosis was not significantly different between SWP and IWP, whereas perioperative complications occurred more frequently in SWP than in IWP.

Registration

URL: https://www.umin.ac.jp; Unique identifier: UMIN000020472.

United States Investigational Device Exemption study of the Revolution™ Peripheral Atherectomy System

OBJECTIVE

Atherectomy has become commonplace as an adjunct to interventional treatments for peripheral arterial disease, but the procedures have been complicated by risks including distal embolization and arterial perforation. This study aimed to examine the safety and effectiveness of a novel atherectomy system to treat femoropopliteal and below-knee peripheral arterial disease.

METHODS

The Revolution Peripheral Atherectomy System (Rex Medical LP, Conshohocken, Pa) was studied in 121 patients with 148 femoropopliteal and below-knee lesions, enrolled at 17 United States institutions. Technical success was defined when the post-atherectomy angiographic stenosis was ≤50%, as assessed by an independent core laboratory. Major adverse events were adjudicated by an independent Clinical Events Committee.

RESULTS

Among 148 site-identified target lesions in 121 patients, 21.4% were in the superficial femoral artery, 13.7% involved the popliteal artery, and 67.9% were in tibial arteries; 3.1% involved more than one segment. Technical success was 90.2%, with stenoses decreasing from 73% ± 19% at baseline to 42% ± 14% after atherectomy. Adjunctive treatment after atherectomy included angioplasty with uncoated balloons in 91%, drug-coated balloons in 11%, bare stent deployment in 8%, and drug-eluting stent placement in 3%. Procedural success (<30% residual stenosis) was achieved in 93.7% of target lesions. Complications during the procedure included one target vessel perforation and two distal embolizations; each of which were adjudicated by the Clinical Events Committee as unrelated to the device and were not visualized angiographically by the core laboratory. Freedom from major adverse events was 97.3% through 30 days. The Kaplan-Meier estimates of primary, assisted primary, and secondary patency were 81.6%, 87.7%, and 91.6% at 6 months, respectively.

CONCLUSIONS

The use of the Revolution Peripheral Atherectomy System was associated with few procedural complications and a high rate of success at the index procedure and through 6 months.

Characteristics of atherosclerosis in femoropopliteal artery and its clinical relevance

Atherosclerosis is a systemic disease with different faces. Despite identical or similar pathogenetic mechanisms, atherosclerotic lesions and their clinical manifestations vary in different parts of the vascular system. Peripheral arterial disease (PAD) represents one of the most frequent clinical manifestations of atherosclerosis with predominant location in the superficial femoral artery (SFA). Morphological characteristics of atherosclerotic plaques in peripheral arteries differ from lesions in the coronary and carotid arteries. Plaques in SFA have more fibrotic components, less lipids and inflammatory cells, which makes them more stable and less prone to rupture. Factors that determine the different structure of plaques in SFA compared to coronary arteries include hemodynamic forces, vasa vasorum and calcification. Low shear stress in SFA in the adductor canal is one of the factors which determines frequent atherosclerotic lesions in this region. Lower lipid content and fewer inflammatory cells explain higher stability of SFA plaques. The specific structure of SFA plaques may require preventive and therapeutic measures, which to some extent differ from prevention of coronary atherosclerosis and may include inhibition of fibrotic proliferation in SFA plaques and calcification. Revascularization of PAD differs from procedures used in coronary arteries and requires specific technical expertise and devices.

CIRSE Standards of Practice on Below-the-Knee Revascularisation

The CIRSE Standards of Practice Committee established a writing group that was tasked with producing up-to-date recommendations for performing below-the-knee revascularisation, taking into account data on novel techniques, devices, and long-term outcomes that have emerged over the last decade. CIRSE Standards of Practice documents are not clinical practice guidelines or systematic reviews of the literature. This document is not intended to impose a standard of clinical patient care but recommends a reasonable approach to and best practices for performing below-the-knee revascularisation.

Safety and effectiveness of Phoenix atherectomy for endovascular treatment in calcified common femoral artery lesions

Background: Traditionally endarterectomy has been considered as the gold standard technique for the treatment of common femoral artery (CFA) lesions. The aim of this study is to investigate the procedural safety and mid-term outcomes of minimal invasive Phoenix atherectomy for the treatment of CFA lesions. Patients and methods: Phoenix atherectomy was used for treatment of 61 consecutive, moderately to heavily calcified CFA lesions in 56 patients. Lesions were classified based on the CFA occlusive disease classification (Type I, II&III lesions). Primary endpoints were technical, procedural, and clinical success rate. Safety endpoints (vessel perforation, peripheral embolization) and clinically driven target lesion revascularization (TLR) were also assessed. Results: Of 61 CFA lesions, 58 (95%) exhibited at least moderate/severe calcification (PACSS3 in 38 (62%) and PACSS4 in 20 (33%) cases). Type III lesions were present in 30 (49%), type I/II lesions in 31 (51%) cases. Technical and procedural success was achieved in 30 (49%) and all 61 (100%) lesions, respectively with low complication rates (0% perforation, 2% embolization). Adjunctive treatment after atherectomy was performed using drug-coated balloon (DCB) in 35 (57%) and bail-out stenting in 6 (10%) cases. Target lesion revascularization (TLR) occurred in 4 (7%) cases during a mean follow-up duration of 11±7months. All patients exhibited clinical improvement at follow-up, showing mean Rutherford category reduction from 3.7±1.1 to 1.5±1.1 (p<0.001). Conclusions: The Phoenix device can be used for the effective endovascular treatment of CFA lesions, due to its reasonable safety profile and mid-term results.

Atherectomy Combined with Balloon Angioplasty versus Balloon Angioplasty Alone for de Novo Femoropopliteal Arterial Diseases: A Systematic Review and Meta-analysis of Randomised Controlled Trials

OBJECTIVE

The efficacy and cost effectiveness of atherectomy for femoropopliteal (FP) arterial diseases have not been determined yet. A systematic review and meta-analysis were performed to compare the efficacy and safety between atherectomy combined with balloon angioplasty (BA) and BA alone for patients with de novo FP steno-occlusive lesions.

METHODS

The Cochrane Library, Medline, and Embase were used to search for studies evaluating outcomes of atherectomy combined with BA compared with BA alone in FP arterial diseases from inception to July 2020. The methodological quality of the included studies was evaluated with the Cochrane Risk of Bias Tool. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) framework was used to assess the level of evidence for each outcome. The fixed effects model was chosen to combine the data when I² < 50%; otherwise, the random effects model was used. Subgroup and sensitivity analyses were performed to further analyse the results.

RESULTS

Four RCTs were included. The meta-analysis showed that atherectomy combined with BA was associated with improved technical success rate (risk ratio [RR] 0.22, 95% confidence interval [CI] 0.13-0.38, p < .001; I² = 0; high quality), reduced bailout stenting (RR 0.15, 95% CI 0.07-0.32, p < .001; I² = 16%; high quality), and flow limiting dissection (RR 0.24, 95% CI 0.13-0.47, p < .001; I² = 0; high quality). No statistically significant difference was found in target lesion revascularisation (TLR), primary patency, mortality, major adverse event (MAE), or ankle brachial index (ABI) after one year follow up.

CONCLUSION

Compared with BA alone, atherectomy combined with BA may not improve primary patency, TLR, mortality rate, or ABI, but may reduce the need for bailout stenting and the incidence of flow limiting dissection and increase the technical success rate in FP arterial diseases. More studies are warranted to further confirm the conclusion.

Drug-coated balloons used in peripheral artery disease: experience from a single center

OBJECTIVE

This retrospective single-center study aimed to analyze immediate and follow-up results of using drug-coated balloons (DCBs) for treating peripheral arterial disease.

METHODS

In this study, we identified a total of 75 patients who underwent DCB therapy at our institution. The ankle-brachial index (ABI) was measured before and after intervention. Intermittent claudication and whether there was healing of ulcers were determined by telephone.

RESULTS

The cohort consisted of 56 men and 19 women aged 38 to 87 years (68 ± 12 years). Twenty-three patients had Rutherford grade III, 15 had Rutherford grade IV, and 37 had Rutherford grade V. Seventeen patients had stents and 18 had the Rotarex system used. The postoperative ABI was significantly greater than the preoperative ABI (0.911 ± 0.173 vs 0.686 ± 0.249). Good results for treatment were obtained. Intermittent claudication and rest pain did not occur in subjects with Rutherford grades III and IV during follow-up. The amputation rate was 4.1% among all patients using DCB therapy during follow-up.

CONCLUSIONS

DCB therapy is safe and effective for treating peripheral arterial disease in real-world patients. Future prospective studies on this issue are recommended.

Distal retrieval of dislodged and migrated guidewires after retrograde puncture of the deep femoral and dorsal pedal artery. A case series

We report on retrograde retrieval of the soft end of dislodged guidewires during complex interventions. Interventionalists may consider this as an option for the endovascular management of this complication if an antegrade retrieval is not possible or fails.

Comparison of morphometric, structural, mechanical, and physiologic characteristics of human superficial femoral and popliteal arteries

Peripheral arterial disease differentially affects the superficial femoral (SFA) and the popliteal (PA) arteries, but their morphometric, structural, mechanical, and physiologic differences are poorly understood. SFAs and PAs from 125 human subjects (age 13-92, average 52±17 years) were compared in terms of radii, wall thickness, and opening angles. Structure and vascular disease were quantified using histology, mechanical properties were determined with planar biaxial extension, and constitutive modeling was used to calculate the physiologic stress-stretch state, elastic energy, and the circumferential physiologic stiffness. SFAs had larger radii than PAs, and both segments widened with age. Young SFAs were 5% thicker, but in old subjects the PAs were thicker. Circumferential (SFA: 96→193°, PA: 105→139°) and longitudinal (SFA: 139→306°, PA: 133→320°) opening angles increased with age in both segments. PAs were more diseased than SFAs and had 11% thicker intima. With age, intimal thickness increased 8.5-fold, but medial thickness remained unchanged (620μm) in both arteries. SFAs had 30% more elastin than the PAs, and its density decreased ~50% with age. SFAs were more compliant than PAs circumferentially, but there was no difference longitudinally. Physiologic circumferential stress and stiffness were 21% and 11% higher in the SFA than in the PA across all ages. The stored elastic energy decreased with age (SFA: 1.4→0.4kPa, PA: 2.5→0.3kPa). While the SFA and PA demonstrate appreciable differences, most of them are due to vascular disease. When pathology is the same, so are the mechanical properties, but not the physiologic characteristics that remain distinct due to geometrical differences.

Novel Receptor for Advanced Glycation End Products-Blocking Antibody to Treat Diabetic Peripheral Artery Disease

Background

Expression of receptor for advanced glycation end products (RAGE) plays an important role in diabetic peripheral artery disease. We proposed to show that treatment with an antibody blocking RAGE would improve hind limb perfusion and muscle viability in diabetic pig with femoral artery (FA) ligation.

Methods and Results

Purpose‐bred diabetic Yucatan minipigs with average fasting blood sugar of 357 mg/dL on insulin to maintain a glucose range of 300 to 500 mg/dL were treated with either a humanized monoclonal anti‐RAGE antibody (CR‐3) or nonimmune IgG. All pigs underwent intravascular occlusion of the anterior FA. Animals underwent (²⁰¹Tl) single‐photon emission computed tomography/x‐ray computed tomography imaging on days 1 and 28 after FA occlusion, angiogenesis imaging with [^99mTc]dodecane tetra‐acetic acid–polyethylene glycol–single chain vascular endothelial growth factor (scVEGF), muscle biopsies on day 7, and contrast angiogram day 28. Results showed greater increases in perfusion to the gastrocnemius from day 1 to day 28 in CR‐3 compared with IgG treated pigs (P=0.0024), greater uptake of [99mTc]dodecane tetra‐acetic acid‐polyethylene glycol‐scVEGF (scV/Tc) in the proximal gastrocnemius at day 7, confirmed by tissue staining for capillaries and vascular endothelial growth factor A, and less muscle loss and fibrosis at day 28. Contrast angiograms showed better reconstitution of the distal FA from collaterals in the CR‐3 versus IgG treated diabetic pigs (P=0.01). The gastrocnemius on nonoccluded limb at necropsy had higher ²⁰¹Tl uptake (percentage injected dose per gram) and reduced RAGE staining in arterioles in CR‐3 treated compared with IgG treated animals (P=0.04).

Conclusions

A novel RAGE‐blocking antibody improved hind limb perfusion and angiogenesis in diabetic pigs with FA occlusion. Contributing factors are increased collaterals and reduced vascular RAGE expression. CR‐3 shows promise for clinical treatment in diabetic peripheral artery disease.

"Failure-to-Cross" in Patients Undergoing Percutaneous Peripheral Intervention: The Nonreimbursed Procedure

BACKGROUND

Percutaneous peripheral intervention (PPI) is often the first mode of therapy for patients with symptomatic arterial occlusive disease. Technical success generally remains high although "failure-to-cross" still complicates 5-20% of cases. Extended efforts to cross long, occlusive lesions can utilize significant hospital and practitioner resources. The hospital is typically reimbursed for this effort as facility fees are charged by the hour and materials are charged per use. However, given the lack of a CPT® code for "failure-to-cross," practitioners are rarely appropriately compensated. The purpose of this study is to analyze the predictors, technical details, outcomes, and costs of "failure-to-cross" during PPI.

METHODS

All PPI procedures over a 2-year period at a single institution were retrospectively reviewed. Clinical characteristics, results, costs, and reimbursements obtained from hospital cost accounting were compared among successful therapeutic interventions, crossing failures, and diagnostic angiograms without attempted intervention.

RESULTS

A total of 146 consecutive PPIs were identified; the rate of "failure-to-cross" was 11.6% (17 patients). The majority of patients with "failure-to-cross" were male (82%) with single-vessel runoff (53%). Compared to successful interventions, the incidences of chronic limb-threatening ischemia (82% vs. 70%, P = 0.34) and infrapopliteal occlusive disease were similar (47% vs. 31%, P = 0.20). "Failure-to-cross" procedures were just as long as successful procedures; there were no significant differences in fluoroscopy time (27 ± 10 vs. 24 ± 14 min, P = 0.52), in-room time (106 ± 98 vs. 103 ± 44 min, P = 0.84), or contrast dye volume utilization (73 ± 37 vs. 96 ± 54 mL, P = 0.12). As expected, "failure-to-cross" procedures incurred far higher hospital charges and costs compared to noninterventional diagnostic angiograms (charges $13,311 ± 6,067 vs. $7,690 ± 1,942, P < 0.01; costs $5,289 ± 2,099 vs. $2,826 ± 1,198, P < 0.01). Despite the additional time and effort spent attempting to cross difficult lesions, the operators were reimbursed at the same low rate as a purely diagnostic procedure (average fee charge $7,360; average reimbursement $992). After 1 year, the 17 patients in whom lesions could not be crossed were treated with advanced interventional procedures with success (n = 2), surgical bypass grafting (n = 5), extremity amputation (n = 4), or no additional intervention in their salvaged limb (n = 6).

CONCLUSIONS

Patients whose lesions cannot be crossed during PPI fare worse than patients undergoing successful interventions. Hospital costs and charges appropriately reflect the high technical difficulty and resource utilization of extended attempts at endovascular therapy. For practitioners, crossing lesions during PPI is truly a "pay-for-performance" procedure in that only successful procedures are reasonably reimbursed.

A Simple and Effective Flow Cytometry-Based Method for Identification and Quantification of Tissue Infiltrated Leukocyte Subpopulations in a Mouse Model of Peripheral Arterial Disease

Arteriogenesis, the growth of a natural bypass from pre-existing arteriolar collaterals, is an endogenous mechanism to compensate for the loss of an artery. Mechanistically, this process relies on a locally and temporally restricted perivascular infiltration of leukocyte subpopulations, which mediate arteriogenesis by supplying growth factors and cytokines. Currently, the state-of-the-art method to identify and quantify these leukocyte subpopulations in mouse models is immunohistology. However, this is a time consuming procedure. Here, we aimed to develop an optimized protocol to identify and quantify leukocyte subpopulations by means of flow cytometry in adductor muscles containing growing collateral arteries. For that purpose, adductor muscles of murine hindlimbs were isolated at day one and three after induction of arteriogenesis, enzymatically digested, and infiltrated leukocyte subpopulations were identified and quantified by flow cytometry, as exemplary shown for neutrophils and macrophages (defined as CD45⁺/CD11b⁺/Ly6G⁺ and CD45⁺/CD11b⁺/F4/80⁺ cells, respectively). In summary, we show that flow cytometry is a suitable method to identify and quantify leukocyte subpopulations in muscle tissue, and provide a detailed protocol. Flow cytometry constitutes a timesaving tool compared to histology, which might be used in addition for precise localization of leukocytes in tissue samples.

VEGF receptor targeted imaging of angiogenic response to limb ischemia in diabetic vs. non-diabetic Yucatan minipigs

Background

New therapies to treat diabetic peripheral artery disease (PAD) require target-specific non-invasive imaging modalities to follow efficacy. As a translational study, we performed targeted imaging of receptors for vascular endothelial growth factor (VEGF) in response to anterior femoral artery occlusion (FAO) in Yucatan minipigs and compare the normal response to response in diabetic Yucatan minipigs.

Methods

Eleven Yucatan minipigs, 6 non-diabetic (non-D) and 5 purpose bred diabetic (D) (Sinclair, Auxvasse MO), underwent intravascular total occlusion of the anterior femoral artery (FA). At days 1 and 28, pigs underwent SPECT/CT ²⁰¹Tl hindlimb perfusion imaging and at day 7 were injected with [^99mTc]DOTA-PEG-scVEGF (scV/Tc) tracer targeting VEGF receptor, and underwent biopsies of the hindlimb muscles for gamma counting and histology, followed by imaging. One day after the final scan, pigs underwent contrast angiography of the lower extremities. Counts from scans were converted to percentage injected activity (%IA).

Results

Perfusion was lower in the occluded hindlimb compared to non-occluded on day 1 in both the D and non-D pigs. At day 7, scV/Tc count ratio of counts from ROIs drawn in proximal gastrocnemius muscle for the occluded over non-occluded limb was significantly higher in non-D vs. D pigs (1.32 ± 0.06 vs. 1.04 ± 0.13, P = 0.02) reflecting higher level of angiogenesis. Perfusion increased between days 1 and 28 in the muscles in the occluded limb for the non-diabetic pigs while the diabetic pig showed no increase (+ 0.13 ± 0.08 %IA vs. − 0.13 ± 0.11, P = 0.003). The anterior FA showed poor contrast filling beyond occluder and qualitatively fewer bridging collaterals compared to non-D pigs at 28 days.

Conclusion

VEGF receptor targeted imaging showed the effects of diabetes to suppress angiogenesis in response to occlusion of the anterior femoral artery of purpose bred diabetic Yucatan minipigs and indicates potential applicability as a marker to follow efficacy of novel therapies to improve blood flow by stimulating angiogenesis in diabetic PAD.

Device Selection in Femoral-Popliteal Arterial Interventions

Endovascular intervention devices for femoral-popliteal arterial disease have evolved in the last decade to more effectively treat patients with symptoms of claudication, improve tissue healing, and prevent amputation in patients with critical limb ischemia. Drug-eluting stents and drug-coated balloon therapies have demonstrated significant improvements in short- and mid-term patency and decreases in future target vessel interventions over uncoated balloon angioplasty. Adjunctive lesion preparation options including atherectomy devices are available to treat more complex and calcified lesions, but comparative data are still required.

Initial Experience in a Pig Model of Robotic-Assisted Intracranial Arteriovenous Malformation (AVM) Embolization

BACKGROUND

Robotic assistance for coronary and peripheral vascular pathologies is steadily gaining popularity. However, it has yet to be applied to neurovascular intervention.

OBJECTIVE

To establish the feasibility of the CorPath® GRX robotic-assisted platform (Corindus Inc, Waltham, Massachusetts) for intracranial arteriovenous malformation (AVM) embolization.

METHODS

This robotic system was used to embolize intracranial AVMs (n = 4) in 2 anesthetized pigs, under controlled conditions appropriate for clinical intervention. Initially, a catheter was manually introduced into the common carotid artery (CCA). Then, the robotic system was used to advance the catheter into the ascending pharyngeal artery (APA) towards the rete mirabilis, which was used as a model for an AVM, using 0.014 in guidewires and 2.4F/1.7F microcatheters. After doing a pre-embolization APA run, which demonstrated good visualization of the rete, dimethyl sulfoxide (DMSO) was instilled into the microcatheter. A negative roadmap was then done, and Onyx was used to embolize the rete.

RESULTS

All 4 AVMs were completely obliterated with no complications, including no contrast extravasation, dissection, thrombosis, or other vascular injury.

CONCLUSION

This study is the first to demonstrate the feasibility of a robotic-assisted platform for intracranial AVM embolization.