Early Recoil After Balloon Angioplasty of Tibial Artery Obstructions in Patients With Critical Limb Ischemia

Popliteal-Distal Bypass Affords Better Limb Salvage than Tibial Angioplasty for Chronic Limb-Threatening Ischemia

OBJECTIVE

Chronic limb-threatening ischemia (CLTI) due to isolated tibial occlusive disease is treated by either popliteal distal bypass or tibial angioplasty, although there is limited data directly comparing efficacy and outcomes between these two treatment modalities. This study compares 30-day mortality and major adverse limb events following infrapopliteal bypass and tibial angioplasty in patients with CLTI.

METHODS

Patients who underwent popliteal distal bypass for CLTI were extracted from American College of Surgeons National Surgical Quality Improvement Program targeted lower extremity open database, whereas patient with CLTI who underwent isolated tibial angioplasty were identified in the targeted lower extremity endovascular database. Any case with more proximal angioplasty such as femoral/pop/iliac was excluded. The time interval was 2011-2022. The two groups were comparable in demographics and pre-operative comorbidities were obtained using propensity matching. Mortality, systemic complications, and major adverse limb events were measured. Multivariable logistic regression was used for data analysis. To obtain granular data on the angiographic characteristics of patients undergoing popliteal-distal bypass or tibial angioplasty, The George Washington University institutional data from 2014 to 2019 was used as supplement to the database.

RESULTS

There were 1,947 and 3,423 cases identified in the bypass and endovascular groups, respectively. After propensity matching for all preoperative variables, 1,747 cases remained in each group. Although bypass was associated with higher major adverse cardiovascular events, pulmonary, renal, and wound complications, bypass had significantly better 30-day limb salvage when compared to tibial angioplasty (major amputation rate 3.32% vs. 6.12%; p<0.01). Institutional data identified 69 patients with CLTI due to isolated tibial occlusive disease; 25 (36.2%) underwent popliteal-distal bypass and 44 (63.8%) underwent tibial angioplasty. Reviewing of angiographic details revealed patients who underwent popliteal-distal bypass had better pedal targets (inframalleolar/pedal score of P0 [24.0% vs 15.9%] or P1 [68.0% vs 61.3%]) than tibial angioplasty patients (inframalleolar/pedal score of P2 [22.7% vs 8.0%]).

CONCLUSION

Popliteal-distal bypass was associated with higher morbidity but better limb salvage than endovascular interventions. However, this could be explained by the association with better pedal targets in patients who underwent popliteal-tibial bypass. Prospective studies should be done comparing popliteal distal bypasses and tibial angioplasty in cases with similar pedal targets.

Perioperative intravenous Iloprost therapy in addition to percutaneous transluminal angioplasty improves patency for peripheral arterial occlusive disease

Introduction: In this study, we aimed to evaluate and compare whether perioperative additional intravenous (IV) Iloprost therapy to percutaneous balloon angioplasty for peripheral arterial occlusive disease improves patency and reintervention.Methods: Between January 2018 and August 2020, 183 patients underwent Percutaneous transluminal angioplasty (PTA) with Drug-Eluting Balloons (DEB) for femoropopliteal lesions (TASC 2 A-C) due to claudication, and 161 patients (133 male, 28 female, mean age 63.65 ± 11.16 years, range 30-86 years) were included in this study. The patients were divided into two groups as DEB+ Intravenous Iloprost administration and DEB alone. Primary patency, reintervention, bailout stenting, and survival rates were analyzed in this retrospective study.Results: Primary patency rate at 12 months (79 vs 57 patients, 89.7 vs 78%, p = 0.041) and assisted primary patency rate (81 vs 59 patients, 92 vs 80.8%, p = 0.035) were found to be higher and Bailout stent deployment was lower in DEB + Iloprost group (3 vs 9 patients, 3.4 vs 12.3% p = 0.031). The reinterventions rate at 12 months was also lower among the DEB + Iloprost group (9 vs 16 patients, 10.2 vs 21.9%, p = 0.041).Conclusion: The present study demonstrated that primary patency at 12 months and assisted primary patency rates, freedom from reintervention was significantly higher and bailout stenting was found to be significantly lower. We believe that perioperative Intravenous Iloprost therapy is beneficial for PTA and improves outcomes.

Outcomes of Noncompliant Balloons in the Treatment of Lower Extremity Chronic Limb Threatening Ischemia: A Prospective Study

PURPOSE

This is a prospective study to investigate the clinical outcomes of using noncompliant balloons in lower limb angioplasty for chronic limb threatening ischemia (CLTI).

MATERIALS AND METHODS

This is a prospective single-center cohort study performed at a local tertiary hospital in Singapore. Consecutive patients who underwent lower limb angioplasty for CLTI using a noncompliant balloon catheter were enrolled if they were aged 40 years and above, presented with CLTI Rutherford grade 4 to 6, and had TASC C or D lesions in the lower limb vessels that were at least 100mm in length. Patient demographics, Rutherford grading, lesion characteristics, complications, and follow-up data were collected and analyzed. The primary outcomes were 30-day freedom from major adverse events, amputation-free survival (AFS) at 12 months, and freedom from clinically driven target lesion revascularization (cdTLR) at 12 months. Secondary outcomes included clinical success and target lesion primary patency (TLPP) at 12 months. Amputation-free survival, freedom from cdTLR, and TLPP were calculated by Kaplan-Meier analysis.

RESULTS

From May 2020 to December 2021, 50 patients (50 limbs) were enrolled. 43 (86%) patients had diabetes mellitus, while 12 patients (24%) had end-stage renal failure. 85 lesions were treated, including 59 (69.4%) below-the-knee (BTK) lesions. All the lesions were TASC C (n=45, 52.9%) or TASC D (n=40, 47.1%) lesions. Mean lesion length was 231.4±116.2mm. Technical success rate was 96.5%. No patients were lost to follow-up. Median follow-up duration was 282 days (IQR: 31-390 days). One patient died on day 26 due to an acute myocardial infarction. Two patients had groin hematomas postprocedure, both of which were treated conservatively. AFS, freedom from cdTLR, and TLPP at 12 months postprocedure was 70.0% (95% confidence interval [CI]: 58.4%-83.9%), 90.1% (95% CI: 83.4%-97.4%), and 61.1% (95% CI: 50.7%-73.6%), respectively.

CONCLUSION

Early results have shown that the use of a high-pressure, noncompliant balloon is effective in lower limb angioplasty for CLTI in a highly challenging group of patients with a high prevalence of long BTK disease. Good vessel patency and limb salvage rates can be achieved, with a low complication rate. We await more long-term outcomes on vessel patency.

CLINICAL IMPACT

There are many devices in the market for use in lower limb angioplasty. However, many of them come with an increased financial cost, procedural time and procedural difficulty. We report our prospective results with the exclusive use of a high pressure, non-compliant balloon, in a challening group of patients with a high prevalence of diabetes and end stage renal failure, achieving amputation free surival at 6 and 12 months post-procedure of 84.0% and 70.0% respectively. The use of non-compliant balloon is technically easy and does not add additional steps compared to a standard POBA procedure, thus limiting costs. We believe this article can be a push factor for clinicians to consider the use of these high pressure, non-compliant balloons in their patient care.

The Utility of Sirolimus Eluting Balloons in the Setting of Chronic Limb Threatening Ischaemia in Asian Patients from Singapore - 12 Months Results of the PRISTINE Registry

PURPOSE

The aim of PRISTINE was to evaluate the 6 and 12 months safety and efficacy of the Selution Sustained Limus Release (SLR)™ sirolimus-coated balloon for treatment of complex lower limb occlusive lesions (TASC II C & D) in patients with chronic limb threatening ischemia (CLTI) from Singapore.

METHODS

PRISTINE was a prospective, non-randomized, single arm, observational, multi-investigator, single-center clinical study. Complication-free survival at 30 days was the safety clinical endpoint. Immediate technical success (ability to cross and dilate the lesion and achieve residual angiographic stenosis < 30%), 6-month primary vessel patency, limb salvage, clinically driven target lesion revascularization (TLR) and amputation free survival (AFS) were the efficacy endpoints of interest.

RESULTS

Seventy five patients were included. There were 50 (68.0%) males; mean age, 69.0 ± 10.7 years. CLTI severity was based on the Rutherford Scale (R5 = 51; R6 = 17). Significant co-morbidities included diabetes mellitus (n = 68; 91.0%) and end-stage renal failure (n = 28; 37.0%). 112 atherosclerotic lesions were treated (TASC II D = 58 (52%); 76 (67%) de novo). There was 100% technical success. Mean lesion length treated was 22.4 ± 13.9 cm. Primary vessel patencies at 6 and 12 months were 64/86 (74%) and 43/74 (58%) and freedom from clinically driven TLR were 72/86 (84%) and 55/74 (74%) respectively. AFS was 61/73 (84.0%; five deaths and seven major lower extremity amputation) at 6-months. Mean Rutherford score improved from 5.1 ± 0.55 at baseline to 1.1 ± 2.05 (p < 0.05) at one year and there was a wound healing rate of 38/48 (79%) at the same timepoint.

CONCLUSIONS

The Selution SLR™ drug eluting balloon is safe and efficacious in treating highly complex infra-inguinal atherosclerotic lesions in an otherwise challenging frail population of CLTI patients with a high incidence of diabetes and end-stage renal failure. It is associated with highly satisfactory acute technical and clinical success, 12-month target lesion patency and AFS.

LEVEL OF EVIDENCE

Level 2b, Individual Cohort Study.

Comparison of Different Endovascular Treatments of Femoropopliteal Artery In-Stent Restenosis: A Systematic Review and Bayesian Network Meta-Analysis

BACKGROUND

This Bayesian network meta-analysis (NMA) sought to evaluate the efficacy of different endovascular treatments for femoropopliteal artery in-stent restenosis (FP-ISR).

METHODS

PubMed, Embase, Cochrane Central Register of Controlled Trials, and Web of science for clinical trials from database inception to March 31, 2023, with no language restrictions to retrieve randomized controlled trials or cohort studies evaluating the impact of any kind of endovascular treatments for FP-ISR. Pair-wise meta-analysis and Bayesian NMA were performed to pool the outcome estimates different endovascular treatments. The primary end points under consideration were primary patency rates at both 6-month and 12-month follow-up.

RESULTS

A total of 15 studies with 1,424 patients were ultimately enrolled to be analyzed, 7 types of endovascular treatment were identified for comparison. In terms of primary patency and freedom from target lesion revascularization (TLR) at 6-month and12-month follow-up, the direct meta-analysis findings showed that drug-coated balloons (DCB) and covered stent (CS) are considerably superior to plain old balloon angioplasty (POBA), Excimer laser atherectomy (ELA) + DCB is significantly better than DCB. According to the meta-analysis based on Bayesian theory, during the 6-month and 12-months follow-up, we could not find significant difference between the different treatments in terms of the primary patency and the freedom from TLR, based on the surface values under the cumulative ranking curve (SUCRA), CS was considered the best treatment in terms of primary patency (6 months SUCRA = 85.2; 12 months SUCRA = 78.9) and freedom from TLR (6 months SUCRA = 84.9; 12 months SUCRA = 70.9); directional atherectomy + POBA may lead to higher survival rate at 12 months (SUCRA = 89.1) than others treatments; in addition, both ELA + POBA and ELA + DCB have higher limb salvage than POBA.

CONCLUSIONS

The findings of this NMA suggest that CS showed positive encouraging results in primary patency and TLR in FP-ISR at 6 and 12 months. However, due to the potential influence of certain confounding factors, the long-term results necessitate validation through numerous randomized controlled trials.

Below-the-Knee Endovascular Revascularization: A Position Statement

Patients with chronic limb-threatening ischemia, the terminal stage of peripheral artery disease, are frequently afflicted by below-the-knee disease. Although all patients should receive guideline-directed medical therapy, restoration of inline flow is oftentimes necessary to avoid limb loss. Proper patient selection and proficiency in endovascular techniques for below-the-knee revascularization are intended to prevent major amputation and promote wound healing. This review, a consensus among an international panel of experienced operators, provides guidance on these challenges from an endovascular perspective and offers techniques to navigate this complex disease process.

Serration Angioplasty Is Associated With Less Recoil in Infrapopliteal Arteries Compared With Plain Balloon Angioplasty

PURPOSE

Recoil following balloon angioplasty of tibial arteries is a known mechanism of lumen loss and widely considered to be a contributing factor in early failure or later restenosis. The Serranator balloon has been designed to provide a controlled lumen gain while minimizing vessel injury. The objective of this study was to assess the ability to define and measure postangioplasty recoil in infrapopliteal arteries and to compare recoil after serration angioplasty and plain balloon angioplasty (POBA).

METHODS

This multi-center, sequential comparative study included patients with de novo or restenotic lesions of infrapopliteal arteries up to 22 cm in length. Patients were enrolled sequentially and underwent alternating POBA or serration angioplasty with Serranator. The study captured angiographic imaging at pre, immediately post, and 15-minute after angioplasty. Vessel recoil, final diameter stenosis, and dissection were compared using core laboratory analysis.

RESULTS

This study enrolled 36 patients who underwent treatment of 39 infrapopliteal lesions. There was no significant difference between Serranator (n=20) and POBA (n=19) with respect to baseline demographics and lesion characteristics. Arterial recoil (>10%) occurred in 25% of Serranator-treated lesions versus 64% in POBA-treated lesions (p=0.02. Clinically relevant recoil (>30%) was present after serration angioplasty in 10% of patients and after POBA in 53% (p=0.01). There was no significant difference in technical success (100% for both), dissection rate between Serranator (5%) and POBA (5.2%).

CONCLUSIONS

Arterial recoil occurs after infrapopliteal angioplasty. Serration angioplasty produces substantially less arterial recoil compared with POBA. Additional studies are needed to assess whether reduced arterial recoil translates into superior long-term clinical outcomes.

CLINICAL IMPACT

Prior studies have demonstrated over 90% recoil in patients after balloon angioplasty (POBA) of the infrapopliteal vessels, which significantly impacts the durability and impact of endovascular interventions in this clinical space. This study compared recoil after infrapopliteal angioplasty with serration angioplasty and POBA. Serration angioplasty produces substantially less arterial recoil compared with POBA. Additional studies are needed to assess whether reduced arterial recoil translates into superior long-term clinical outcomes.

Extravascular Ultrasound (EVUS) to Assess the Results of Peripheral Endovascular Procedures

Contrast arteriography (CA) is considered the gold standard to evaluate any phase in peripheral arterial disease (PAD) interventions, from diagnostics to final results. Nevertheless, duplex ultrasonography (DUS) mostly used for the pre/postoperative phase and follow-up control, could be a potential intraoperative adjunctive imaging tool to assess the effects of endovascular revascularization in patients with iliac and femoropopliteal lesions. The PAD “duplex-assisted” protocol includes a preoperative DUS control followed by an intraoperative and a postoperative control. The most important parameters are pulsed doppler spectral analysis and waveform changes, which are impossible to detect with intravascular ultrasound (IVUS). By using a similar acronym, the intraoperative DUS has been previously described as extravascular ultrasound (EVUS). B-mode imaging, color flow, and peak systolic velocity (PSV) are considered. EVUS could be very useful to evaluate the effects of endovascular treatment, mainly in cases of unclear CAs, severe calcifications and/or dissections. In the context of the “leaving nothing behind” strategy, EVUS can drive the physician to evaluate the absence of flow-limiting dissections and decide which target lesion should be treated with antirestenotic therapy, further vessel preparation, or stenting. The EVUS protocol could be a safe and feasible option to improve the completion assessment of endovascular PAD treatment. A better ultrasound waveform is a sign of improved luminal gain and compliance, which is extremely important to finalize the results of new peripheral device technology, such as intravascular lithotripsy.

Intravascular Lithotripsy in Calcified Peripheral Lesions: Single-Center JEN-Experience

Peripheral artery disease (PAD) shows increasing need for revascularization therapy. Interventional success in calcified lesions is limited. Here, intravascular lithotripsy (IVL), modifying intimal and medial calcium, is a promising treatment approach. A single-center, prospective all-comers registry for patients undergoing peripheral IVL was established to examine treatment success in PAD with severe vessel calcification. Periprocedural safety events as well as short-term and intermediate follow-up clinical data were evaluated. Between December 2018 and January 2021 all consecutive patients receiving peripheral lithotripsy at our center were analyzed. Clinical and angiographic data were evaluated. Angiographic images were analyzed using a semiautomatic software for quantitative vessel analysis. Eighty-five lesions in 61 limbs were treated with IVL in 51 patients presenting with Rutherford classes 2 to 5. Most lesions (68%) were localized in the superficial femoral artery. Mean calcified lesion length was 102.5 mm (10-390 mm), with a median peripheral arterial calcium score of 3, indicating a highly calcified status. In 58% of the patients, IVL was used as a stand-alone therapy. IVL resulted in a mean acute luminal gain of 2.6 ± 0.9 mm, resulting in stenosis reduction by 42.1 ± 15%. Mean ankle brachial index (ABI) improved significantly from 0.6 to 0.8 ( p  < 0.0001) on day 1 after the intervention and remained stable at 6 months. This large real-world data of peripheral IVL reports compelling safety in a complex patient cohort. For the first time, clinical follow-up data demonstrated a sustained significant improvement in ABI after 6 months.

Combination therapy using scoring and sirolimus drug-coated balloons during lower limb endovascular revascularization for chronic limb threatening ischaemia: A case series

The aim of this case series was to document our early experience using combination therapy with UltraScore™ Focused Force percutaneous transluminal angioplasty balloon (BD Interventional, New Jersey, US) and Selution Sustained Limus Release (SLR)™ (M.A. MedAlliance SA, Nyon, Switzerland) sirolimus-coated balloon catheter for anti-restenotic drug elution, in the setting of multifocal high-grade stenosis for chronic limb threatening ischaemia. Our anecdotal experience was that preparing the lesion with scoring balloon and then using sirolimus drug-eluting balloon may have synergistic effect when used in tandem, especially in the setting of calcified arterial lesions, where the scoring wires may achieve deeper clefts within the atheromatous plaque to allow better drug absorption into the arterial wall. We report two cases with high-grade multifocal stenosis affecting the superficial femoral and anterior tibial arteries, respectively. Combination therapy using the scoring balloon to first prepare the lesion followed by sirolimus elution achieved technical and procedural success in both cases and a 100% 30-day primary patency. There were no complications related to flow-limiting dissections, vessel perforation or acute recoil. However, whether this combination therapy leads to better primary vessel patency with longer freedom from target lesion revascularization in the medium term remains to be determined.

Creating a Natural Vascular Scaffold by Photochemical Treatment of the Extracellular Matrix for Vascular Applications

The development of bioscaffolds for cardiovascular medical applications, such as peripheral artery disease (PAD), remains to be a challenge for tissue engineering. PAD is an increasingly common and serious cardiovascular illness characterized by progressive atherosclerotic stenosis, resulting in decreased blood perfusion to the lower extremities. Percutaneous transluminal angioplasty and stent placement are routinely performed on these patients with suboptimal outcomes. Natural Vascular Scaffolding (NVS) is a novel treatment in the development for PAD, which offers an alternative to stenting by building on the natural structural constituents in the extracellular matrix (ECM) of the blood vessel wall. During NVS treatment, blood vessels are exposed to a photoactivatable small molecule (10-8-10 Dimer) delivered locally to the vessel wall via an angioplasty balloon. When activated with 450 nm wavelength light, this therapy induces the formation of covalent protein–protein crosslinks of the ECM proteins by a photochemical mechanism, creating a natural scaffold. This therapy has the potential to reduce the need for stent placement by maintaining a larger diameter post-angioplasty and minimizing elastic recoil. Experiments were conducted to elucidate the mechanism of action of NVS, including the molecular mechanism of light activation and the impact of NVS on the ECM.

Device profile of the FLEX Vessel Prep System for the treatment of peripheral arterial disease: overview of its safety and efficacy

INTRODUCTION

The standard endovascular treatment for obstructed peripheral arterial disease (PAD) lesions and stenosed arteriovenous (AV) fistulae is percutaneous transluminal angioplasty (PTA). Despite consistent effectiveness in restoring blood flow, PTA does introduce risk of uncontrolled dissections that require stenting. The FLEX Vessel Prep™ System (FLEX VP) is a novel, dynamic, self-sizing, nonballoon device designed to modify obstructive stenoses and plaque, improve vessel compliance and facilitate delivery of drug therapies by creating longitudinal, controlled-depth, circumferential microincisions along the entire length of a lesion.

AREAS COVERED

In this profile, the mechanism of action of the FLEX VP system is described and differentiated. Acute procedural complications and long-term clinical outcomes following FLEX VP+PTA are presented. Specifically, the unmet clinical need for safe and effective vessel preparation in long, complex, mixed morphology PAD lesions is highlighted.

EXPERT OPINION

The FLEX VP system is an innovative approach to create predictable and consistent longitudinal microincisions in long lesions that improve acute luminal gain and vessel compliance by releasing circumferential tension in the lesion. This nonballoon-based device for plaque modification is safe, effective, easy-to-use, and minimizes PTA-associated dissections, therefore reducing stenting, supporting the 'leave nothing behind' incentive of physicians, and improving long-term clinical outcomes with less vessel trauma.

Technical Success and Mid-Term Outcomes of Endovascular Revascularization of Tibio-Peroneal Trunk Lesions

Tibio-peroneal trunk (TPT) lesions are usually categorized as ‘complex’ in anatomical classifications, which leads to the perception that endovascular therapy (EVT) will be challenging and the outcome most likely poor. This multicenter, retrospective cohort study investigates the efficacy of the EVT of TPT lesions in patients with chronic limb threatening ischemia (CLTI) or an infrapopliteal bypass at risk. The primary endpoint was limb-salvage. The secondary outcomes were technical success, freedom from clinically driven target lesion revascularization (CD-TLR), overall survival, and amputation-free survival. A total of 107 TPT lesions were treated in 101 patients. At 3 years, the limb-salvage rate was 76.4% (95% CI 66.0–86.8%). Technical success was achieved in 96.3% of cases. The freedom from CD-TLR, amputation-free survival, and overall survival at 3 years were 53.0% (95% CI 38.1–67.9%), 33.6% (95% CI 23.0–44.2%), and 47.7% (95% CI 36.1–59.3%), respectively. Reintervention significantly increased the hazard ratio for amputation by 7.65 (95% CI 2.50–23.44, p < 0.001). Our results show that the EVT of both isolated and complex TPT lesions is associated with high technical success and acceptable limb-salvage rates, with reintervention being a major risk factor for amputation. Moreover, mid-term mortality rate was relatively high. In future revisions of the anatomical grading scales, the classification of TPT lesions as highly complex should be reconsidered.

Intravascular Lithotripsy for Treatment of Calcified Infrapopliteal Lesions: Results from the Disrupt PAD III Observational Study

PURPOSE

To evaluate the safety and effectiveness of the Shockwave S⁴ intravascular lithotripsy (IVL) catheter in an "all-comers" cohort of patients with calcified infrapopliteal lesions.

MATERIALS AND METHODS

The Disrupt PAD III Observational Study (NCT02923193) is a prospective, nonrandomized, multicenter single-arm study designed to assess the "real-world" acute safety and effectiveness of the Shockwave Peripheral IVL System for the treatment of de novo calcified, stenotic peripheral arteries. Patients were eligible for enrollment if they had claudication or critical limb ischemia (CLI) and at least moderate calcification as assessed by angiography. This subanalysis includes consecutive patients enrolled with angiographic core lab-assessed treatment of infrapopliteal arteries using the Shockwave S⁴ IVL catheter.

RESULTS

From July 2018 to August 2020, 101 patients with 114 calcified infrapopliteal arteries treated with the S⁴ IVL catheter were enrolled at 15 sites in 3 countries. CLI was present in 69.3% of patients. The anterior tibial and tiboperoneal trunk were the most commonly treated vessels with an overall mean reference vessel diameter (RVD) of 3.1±0.8 mm, minimum lumen diameter (MLD) of 0.5±0.6 mm, and a corresponding diameter stenosis of 83.4%±15.8% by core lab assessment. Mean lesion length was 64.7±54.7 mm with moderate to severe calcification in 69.3% of lesions by the Peripheral Academic Research Consortium (PARC) criteria. Adjunctive calcium-modifying technology, defined as scoring or cutting balloon and/or atherectomy, was used in 22.7% of procedures. The average acute gain at the end of the procedure was 2.0±0.7 mm with a residual stenosis <50% achieved in 99.0% of lesions and a mean residual stenosis of 23.3±12.5%. There were no flow-limiting dissection, embolization, slow flow/no-reflow, or abrupt closure events at the end of the procedure.

CONCLUSION

This subanalysis of the PAD III Observational Study represents the largest report to-date of IVL treatment of heavily calcified below-the-knee (BTK) lesions in a "real-world" patient cohort. The use of S⁴ IVL demonstrated consistent acute safety and effectiveness outcomes consistent with prior IVL peripheral studies. These consistent outcomes were achieved with the initial use of the S⁴ IVL catheter for treatment of complex BTK lesions.

Induced endothelial cells from peripheral arterial disease patients and neonatal fibroblasts have comparable angiogenic properties

Induced endothelial cells (iECs) generated from neonatal fibroblasts via transdifferentiation have been shown to have pro-angiogenic properties and are a potential therapy for peripheral arterial disease (PAD). It is unknown if iECs can be generated from fibroblasts collected from PAD patients and whether these cells are pro-angiogenic. In this study fibroblasts were collected from four PAD patients undergoing carotid endarterectomies. These cells, and neonatal fibroblasts, were transdifferentiated into iECs using modified mRNA. Endothelial phenotype and pro-angiogenic cytokine secretion were investigated. NOD-SCID mice underwent surgery to induce hindlimb ischaemia in a murine model of PAD. Mice received intramuscular injections with either control vehicle, or 1 × 106 neonatal-derived or 1 × 106 patient-derived iECs. Recovery in perfusion to the affected limb was measured using laser Doppler scanning. Perfusion recovery was enhanced in mice treated with neonatal-derived iECs and in two of the three patient-derived iEC lines investigated in vivo. Patient-derived iECs can be successfully generated from PAD patients and for specific patients display comparable pro-angiogenic properties to neonatal-derived iECs.

Atherectomy and Drug-Coated Balloon Angioplasty for the Treatment of Long Infrapopliteal Lesions: A Randomized Controlled Trial

[Figure: see text].

Physician initiated, prospective, non-randomized Multi-center trial, Investigating the safety and Efficacy of the TReatment with the LuminorTM Drug Coated Balloon and the AngioliteTM Drug Eluting Stent of IVascular in TASC C and D Tibial Occlusive disease iN patients with critical limb ischemia: 12-month results

BACKGROUND

The aim of MERLION (NCT04073121) was to evaluate the outcomes of the mono or combination therapy of the iVascular LuminorTM drug coated balloon (DCB) and AngioliteTM drug eluting stent for treatment of TASC II C/D tibial occlusive lesions in Asian patients presenting with chronic limb threatening ischemia (CLTI) from Singapore.

METHODS

MERLION was a prospective, non-randomized, single arm, observational, multicenter clinical study. Complication-free survival at one month was the safety endpoint. Immediate technical success, 12-month primary vessel patency, limb salvage, freedom from target lesion revascularization (TLR) and amputation free survival (AFS) were the efficacy endpoints of interest.

RESULTS

50 patients were included. There were 32 males (64% males; mean age 66.4±8.9 years). Majority were Rutherford 5 severity (41/50; 82%). Co-morbidities included diabetes mellitus (47/50; 94.0%), end-stage renal failure (25/50; 50.0%), and hypertension (44/50; 88%). 66 atherosclerotic lesions were treated (47 de novo and 19 restenotic; 60.6% TASC C and 39.4% TASC D). Mean lesion length treated was 13.7±9.5cm. There was 100% technical success. There were 3/66 (4.5%) bailout stenting for severe flow limiting dissections. 12-month primary tibial patency was 34/49 (69.4%) and freedom from TLR was 40/49 (81.5%). AFS was 74.0% (37/50). At 12 months, mean Rutherford scores improved from 100% (Rutherford score>3) at baseline to 31% at 12 months (p<0.05) and wound healing rate was 65.7%.

CONCLUSIONS

The iVascular LuminorTM DCB is safe and efficacious in treating highly complex infra-popliteal atherosclerotic lesions in an otherwise challenging frail population of CLTI patients from Singapore.

World's First Experience Treating TASC II C and D Tibial Occlusive Disease Using the Selution SLR Sirolimus-Eluting Balloon: Six-Month Results From the PRESTIGE Study

Purpose:

The performance of sirolimus-coated devices has not been studied in patients with chronic limb-threatening ischemia patients. PRESTIGE aims to investigate the 6-month efficacy and safety profile of the Selution Sustained Limus Release (SLR) sirolimus-eluting balloon for treatment of TASC II C and D tibial occlusive lesions in patients with CLTI.

Materials and Methods:

PRESTIGE is a pilot prospective, nonrandomized, single-arm, multi-investigator, single-center clinical study. Endpoints were adverse event-free survival at 1 month, technical success rate, primary tibial patency at 6 months, limb salvage success, target lesion revascularization (TLR), and amputation free survival (AFS).

Results:

A total of 25 patients were included. There were 17 (68.0%) males; mean age, 63.7±9.73 years. CLTI severity was based on the Rutherford scale (R5=25/25; 100.0%). Significant comorbidities included diabetes mellitus (n=22; 88.0%) and end-stage renal failure (n=11; 44.0%). A total of 33 atherosclerotic lesions were treated (TASC II D=15 (45.5%)). Mean lesion length treated was 191±111 mm. Technical success was 100%. Primary tibial patency at 6 months was 22/27 (81.5%) and freedom from clinically driven TLR was 25/30 (83.3%). AFS was 21/25 (84.0%; 3 deaths and 1 major lower extremity amputation). Mean Rutherford score improved from 5.00 at baseline to 1.14±2.10 (p<0.05) at 6 months. There was a wound healing rate of 13/22 (59.1%) and 17/21 (81.0%) at 3 and 6 months respectively.

Conclusions:

Selution SLR drug-eluting balloon is a safe and efficacious modality in treating complex tibial arterial occlusive lesions in what is an otherwise frail cohort of CLTI patients, with a high prevalence of diabetes and end-stage renal failure. Technical and clinical success rates are high and 6-month target lesion patency and AFS are more than satisfactory.

The Association of Preoperative Characteristics with Reintervention Risk in Patients Undergoing Revascularization for Chronic Limb-Threatening Ischemia

AIM

To investigate the associations between preoperative characteristics and the risk of reintervention in patients undergoing revascularization for chronic limb-threatening ischemia (CLTI) in a contemporary real-world setting.

METHODS

We retrospectively analyzed data from a clinical database formed by the Surgical Reconstruction Versus Peripheral Intervention in Patients With Critical Limb Ischemia (SPINACH) study, which was a multicenter, prospective, observational study. The study population was composed of 520 CLTI patients with the wound, ischemia, and foot infection (WIfI) classes I-3 with resting pain or classes I-2/3 with ulcers/gangrene. Of the 520 patients, 192 had surgical reconstruction planned, whereas 328 had endovascular therapy (EVT) alone planned at the time of registration. The current analysis was conducted to explore the associations between preoperative characteristics and the risk of reintervention.

RESULTS

A total of 452 participants (87%) completed the 3-year follow-up regarding reintervention. The competing risk analysis estimated that the three-year cumulative incidence rates for reintervention and reintervention-free deaths were 44.0% and 28.7%, respectively. No preoperative characteristics had a significant interaction effect with EVT versus surgical reconstruction. The risk analysis identified the following independent risk factors for reintervention: 1) EVT instead of bypass reconstruction, 2) renal dysfunction, 3) history of revascularization after CLTI onset (i.e., requirement of redo revascularization for CLTI), and 4) bilateral CLTI. Patients with more than one of these risk factors had an increased risk of reintervention.

CONCLUSIONS

The current study identified preoperative characteristics associated with an increased risk of reintervention. No preoperative characteristics had any significant interactions with EVT or surgical reconstruction.

The Association of Preoperative Characteristics with Reintervention Risk in Patients Undergoing Revascularization for Chronic Limb-Threatening Ischemia

AIM

To investigate the associations between preoperative characteristics and the risk of reintervention in patients undergoing revascularization for chronic limb-threatening ischemia (CLTI) in a contemporary real-world setting.

METHODS

We retrospectively analyzed data from a clinical database formed by the Surgical Reconstruction Versus Peripheral Intervention in Patients With Critical Limb Ischemia (SPINACH) study, which was a multicenter, prospective, observational study. The study population was composed of 520 CLTI patients with the wound, ischemia, and foot infection (WIfI) classes I-3 with resting pain or classes I-2/3 with ulcers/gangrene. Of the 520 patients, 192 had surgical reconstruction planned, whereas 328 had endovascular therapy (EVT) alone planned at the time of registration. The current analysis was conducted to explore the associations between preoperative characteristics and the risk of reintervention.

RESULTS

A total of 452 participants (87%) completed the 3-year follow-up regarding reintervention. The competing risk analysis estimated that the three-year cumulative incidence rates for reintervention and reintervention-free deaths were 44.0% and 28.7%, respectively. No preoperative characteristics had a significant interaction effect with EVT versus surgical reconstruction. The risk analysis identified the following independent risk factors for reintervention: 1) EVT instead of bypass reconstruction, 2) renal dysfunction, 3) history of revascularization after CLTI onset (i.e., requirement of redo revascularization for CLTI), and 4) bilateral CLTI. Patients with more than one of these risk factors had an increased risk of reintervention.

CONCLUSIONS

The current study identified preoperative characteristics associated with an increased risk of reintervention. No preoperative characteristics had any significant interactions with EVT or surgical reconstruction.

Retained Functionality of Atherosclerotic Human Arteries Following Photoactivated Linking of the Extracellular Matrix by Natural Vascular Scaffolding Treatment

In this study, we investigated natural vascular scaffolding (NVS) treatment on vascular functionality using freshly isolated human popliteal arteries in vitro. Arteries were exposed to intraluminal NVS treatment consisting of a compound (4 amino-1,8-naphthalimide) photoactivated by a 450-nm light-emitting light fiber placed inside the artery. This procedure results in covalent linking between the extracellular matrix proteins to achieve a larger vessel diameter post-angioplasty and minimizing elastic recoil. Immediately following NVS treatment, rings were cut from the treated arteries and mounted in organ baths for contractility testing in response to U46619 and sodium nitroprusside. We also investigated the effect of NVS treatment on IL-6 cytokine release from vascular rings following a 4-h organoculture post-NVS treatment. Based on our results, we conclude that exposure of the vessels to NVS treatment does not adversely affect the contractile responsiveness of the vascular smooth muscle and exerts no pro-inflammatory effect. Graphical abstract.

Utility of a novel high pressure non-compliant balloon for tibial atherosclerotic lesions in Asian patients with chronic limb threatening ischaemia

Background: The aim was to evaluate the safety and efficacy of a high pressure, non-compliant balloon in the treatment of infrapopliteal occlusive disease in Asian patients with chronic limb threatening ischaemia (CLTI) from Singapore. Patients and methods: Prospective, multi-centre, single arm, non-randomized study. Immediate technical success, 6-month primary vessel patency (determined by Duplex ultrasonography), limb salvage, one-year clinically driven target lesion re-intervention (TLR) and amputation free survival (AFS) were the efficacy endpoints of interest. Results: 86 patients (63% males, mean age 68.9 ± 9.9 years) were enrolled over a 15-month period. Diabetes mellitus (DM) and end-stage renal failure (ESRF) were present in 94% and 38% of patients respectively. All had some degree of tissue loss at baseline (Rutherford scale 5 and 6 = 91% and 9% respectively). Of the 86 legs, 72% had 3 crural vessel disease and 84% had moderate/severe vessel wall calcification. 90% had > = 1 TASC D tibial lesion. Acute technical success was 89%. One month mortality was 3.5% and one-year freedom from TLR was 91%. 6-month tibial patency was 73%. 54/66 (82%) patients had at least one target treated tibial artery open at 6 months. A lower baseline toe pressure (OR 1.03, 95%CI 1.00-1.05) and elastic recoil post angioplasty (OR 0.20, 95%CI 0.05-0.79) were associated with a worse 6 month tibial patency. One-year AFS was 67%. 47/66 (71%) patients had a clinical improvement of at least one Rutherford class at 6 months and 52/59 (88%) experienced complete wound healing at 12 months. Conclusions: Use of a high pressure non-compliant balloon is safe and efficacious in treating highly complex infra-popliteal atherosclerotic lesions in an otherwise challenging population of CLTI patients with a high incidence of DM and ESRF. It is associated with highly satisfactory acute technical success, 6-month target lesion patency and one-year limb salvage.

Intravascular Ultrasound–Guided Interventions for Below-the-Knee Disease in Patients With Chronic Limb-Threatening Ischemia

Purpose: To assess the utility of intravascular ultrasound (IVUS) during below-the-knee (BTK) interventions for patients with chronic limb-threatening ischemia (CLTI). Materials and Methods: This retrospective single-center study included 216 symptomatic patients (mean age 74.2±9.5 years; 167 men) with CLTI and BTK steno-occlusive disease who underwent successful balloon angioplasty between January 2016 and August 2018. Data from 88 vessels (58 patients) treated with IVUS-guided procedures were compared with corresponding values from 242 vessels (158 patients) treated with angiography-guided procedures. The primary outcomes included procedure-related variables of balloon size, contrast dose, and complication rates, as well as changes in ankle-brachial index (ABI) and skin perfusion pressure (SPP). Secondary outcomes included IVUS determination of vessel size, wire route, and calcification severity, as well as technical success and clinically-driven target lesion revascularization (TLR), limb salvage, and wound healing rates in the Rutherford category 5/6 patients as evaluated by propensity score matching analysis. Results: The patient and lesion characteristics were similar in both groups. The mean balloon size for IVUS-guided procedures was significantly larger (2.45±0.4 mm) compared with that for angiography-guided procedures (2.23±0.4 mm; p<0.001). The technical success (p=0.56) and complication rates (p=0.16) were similar between the groups. The postprocedure dorsal and plantar SPP and change in dorsal SPP improved more in the IVUS-guided group (p<0.001, p=0.015, and p=0.02, respectively). The IVUS-guided group had a significantly better wound healing rate than the angiography-guided group (p=0.006), although the freedom from TLR and limb salvage rates were similar between the groups (p=0.16 and p>0.99, respectively). Conclusion: IVUS-guided interventions for BTK lesions were safe and effective in accurately assessing the lesions. The results suggest that IVUS guidance of endovascular procedures has the potential to influence better clinical outcomes than angiography-guided angioplasty.

Balloon Angioplasty of Infrapopliteal Arteries: A Systematic Review and Proposed Algorithm for Optimal Endovascular Therapy

Endovascular revascularization has been increasingly utilized to treat patients with chronic limb-threatening ischemia (CLTI), particularly atherosclerotic disease in the infrapopliteal arteries. Lesions of the infrapopliteal arteries are the result of 2 different etiologies: medial calcification and intimal atheromatous plaque. Although several devices are available for endovascular treatment of infrapopliteal lesions, balloon angioplasty still comprises the mainstay of therapy due to a lack of purpose-built devices. The mechanism of balloon angioplasty consists of adventitial stretching, medial necrosis, and dissection or plaque fracture. In many cases, the diffuse nature of infrapopliteal disease and plaque complexity may lead to dissection, recoil, and early restenosis. Optimal balloon angioplasty requires careful attention to assessment of vessel calcification, appropriate vessel sizing, and the use of long balloons with prolonged inflation times, as outlined in a treatment algorithm based on this systematic review. Further development of specific devices for this arterial segment are warranted, including devices for preventing recoil (eg, dedicated atherectomy devices), treating dissections (eg, tacks, stents), and preventing neointimal hyperplasia (eg, novel drug delivery techniques and drug-eluting stents). Further understanding of infrapopliteal disease, along with the development of new technologies, will help optimize the durability of endovascular interventions and ultimately improve the limb-related outcomes of patients with CLTI.

High-pressure, non compliant balloon angioplasty for long and calcified infrapopliteal and inframalleolar lesions is feasible

BACKGROUND

To evaluate the safety, feasibility and effectiveness of high-pressure, noncompliant balloon angioplasty in the management of long infrapopliteal calcified lesions.

METHODS

Consecutive patients, presenting with chronic limb-threatening ischemia (CLTI) and long (>100 mm) calcified infrapopliteal lesions who were treated with a high pressure, noncompliant balloon (JADE, OrbusNeich, Hong Kong) between January 2016 and July 2016 were retrospectively analyzed. Angioplasty was performed by inflating the balloon to a pressure of 22 to 24 atm for 90 seconds. Primary outcome was technical success. Secondary outcomes were procedure-related complications, limb salvage, amputation-free survival (AFS), wound healing, overall survival, freedom from clinically driven target lesion reintervention (CD-TLR), and resolution of CLTI at 2 and 3 years.

RESULTS

Overall, 23 lesions in 21 limbs of 20 patients were treated. All patients had tissue loss (Rutherford 5 or 6). The mean lesion length was 374.8 mm. Of all lesions, 56.5% were occlusions, 91.3% were classified as TransAtlantic Inter-Society Consensus (TASC) C and D lesions, and 78.3% had severe calcification classification. Of all lesions, 52.2% extended into the below-the-ankle arteries. Technical success was achieved in 22 lesions (95.7%). There were no procedure-related complications. No bailout stenting was required. At 2 and 3 years, limb salvage was 84.7% and 78.7%, AFS was 71.4% and 56.1%, wound healing was 81.0% and 85.7%, overall survival was 75.0% and 64.3% and freedom from CD-TLR was 77.6% and 63.5%, respectively. Resolution of CLTI without TLR was 81.0% at 2 and 3 years.

CONCLUSIONS

This study is the first to analyze safety and feasibility of a high-pressure, noncompliant balloon for long, calcified infrapopliteal and inframalleolar lesions.

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

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

Practical Applications of Tack Implants for Infrainguinal Dissection Repair: A Single-Center Experience

Purpose: To assess the practical application and acute outcomes of the Tack Endovascular System for infrainguinal dissection repair in a real-world setting. Materials and Methods: Fifty-one consecutive patients who underwent endovascular revascularization for symptomatic peripheral artery disease and experienced 63 dissections requiring treatment were included in the prospective, single-center, single-arm study between January and June 2019. Thirty-nine (76.5%) lesions were ≥10 cm in length, 33 (64.7%) were totally occluded, and 13 (25.5%) were severely calcified. Fifty-six (88.9%) dissections were classified as severe. Dissections were treated either by means of the 6-F above-the-knee (ATK) or the 4-F below-the-knee (BTK) Tack Endovascular System. Observational outcomes were conditions and scopes of application. Clinical outcomes were acute technical and procedural success as well as safety. Results: Lesions were revascularized with 2.3±0.8 attempts such as standard balloon angioplasty, drug-coated balloon angioplasty, atherectomy, and/or lithotripsy. The Endovascular System was applied in 60 (95.2%) of 63 dissections. All dissections of the femoral artery were treated with the ATK system, and all infrapopliteal dissections with the BTK system. Both systems were successfully applied in popliteal artery dissections. Dissection length predicted the number of Tack implants deployed. Technical success was achieved in 98.3% (59 of 60 dissections). No major adverse event or device-related complication occurred during the procedure. Conclusion: Acute results in effectiveness and safety of the Tack Endovascular System for infrainguinal dissection repair in a real-world setting are promising.

Drug-Coated Balloon Angioplasty of Infrapopliteal Lesions in Patients with Critical Limb Ischaemia: 1-Year Results of the APOLLO Trial

PURPOSE

This study intended to assess effectiveness and safety of the drug-coated balloon (DCB) angioplasty of infrapopliteal atherosclerotic lesions in patients with critical limb ischaemia (CLI) in a real-world setting.

METHODS

Consecutive patients with critical limb ischaemia who underwent infrapopliteal drug-coated balloon angioplasty with the ELUTAX SV DCB were enrolled into the prospective, multicentre, single-arm observational registry. Primary outcome was clinical improvement at 6 and 12 months. Secondary outcomes were change in quality of life, primary patency, freedom from repeat revascularisation, and amputation-free survival at 6 and 12 months.

RESULTS

A total of 164 patients (74.7 ± 9.2 years) with CLI were included at nine German sites between November 2015 and September 2017. The majority (79.9%) of patients had diabetes mellitus, 57.3% had renal insufficiency, and 35.3% had coronary artery disease. Mean lesion length was 71.2 ± 76.5 mm. The Rutherford category improved by 3.0 ± 2.0 (p < 0.0001) within 12 months, resulting in a clinical improvement by at least one Rutherford category in 80.2% of the patients. Walking impairment questionnaire score, European Quality of Life index, and patient-reported pain improved significantly from baseline to 6 and 12 months. Primary patency was 68.5%, freedom from target lesion revascularisation 90.6%, and amputation-free survival 83.5% at 12 months.

CONCLUSION

Infrapopliteal drug-coated balloon angioplasty with the ELUTAX SV DCB in patients with critical limb ischaemia was efficacious and safe over the medium term. The study is registered with Clinical.Trials.gov (Identifier: NCT02539940).

Antiplatelet therapy for tibial balloon angioplasty: A clinical perspective

Percutaneous transluminal tibial balloon angioplasty has an important role in the therapeutic approach of critical limb ischaemia. Despite a growing number of patients with critical limb ischaemia, there are no trials to guide the pharmacologic approach post intervention. Guidelines pertaining to the antiplatelet therapy post percutaneous transluminal tibial balloon angioplasty have not been developed. In addition, critical limb ischaemia patients have multiple comorbidities and a higher risk of bleeding. To examine the shortest duration of antiplatelet therapy post percutaneous transluminal tibial balloon angioplasty, we reviewed the preclinical data used to develop the standards for the current angioplasty technique.

The evidence to support the use of focal force balloon technology to improve outcomes in the treatment of lower extremity arterial occlusive disease

Despite recent advances in endovascular therapy of lower extremity atherosclerotic disease, mainly driven through drug eluting balloon angioplasty, treatment of complex lesions remains challenging. Drug-eluting balloons work less well in heavily calcified lesions and in particular long lesions often require bail-out stenting. Lesion preparation, as a stand-alone treatment or before delivering antiproliferative therapy or scaffolding, has gained increased recognition in recent years. Focal force or other specialty balloons are designed to prepare complex lesions to improve acute technical success and, ideally, long term patency of the vessel. There are numerous dedicated balloons on the market that use different modes of action to prepare the lesions. The current review focuses on mechanistic insights and the evidence behind those specialty balloons.

Early Recoil After Balloon Angioplasty of Erection-Related Arteries in Patients With Arteriogenic Erectile Dysfunction

Purpose: To evaluate the incidence of elastic recoil in patients presenting with erectile dysfunction (ED) undergoing endovascular revascularization of the pudendal or penile arteries. Methods: A consecutive series of 21 ED patients (mean age 58.3±9.3 years) undergoing minimally invasive revascularization of 31 arteries was analyzed. ED lesions included the pudendal arteries (n=27) and the penile artery (n=4). Mean lesion length was 20.6±13.9 mm. Minimal lumen diameter (MLD) measurements were assessed at baseline, immediately after balloon angioplasty, and 10 minutes thereafter. Early recoil was defined as an MLD reduction >10%. Elastic recoil with >10% lumen compromise was treated with drug-coated balloons, while severe elastic recoil (>30%) required drug-eluting stents (DES). The International Index of Erectile Function (IIEF-15) score was obtained prior to and 3 months after the procedure to obtain information on functional outcomes subsequent to angioplasty. Results: Mean MLD at baseline was 0.9±0.6 mm, which improved to 2.0±0.9 mm immediately after balloon dilation. At 10 minutes after dilation, the MLD was 1.7±1.0 mm. Elastic recoil was observed in all 31 lesions and resulted in a mean lumen compromise of 21.2%. Severe (>30%) recoil was observed in 14 arteries, which underwent DES therapy. The IIEF-15 score improved from 31.3±11.2 at baseline to 49.8±16.8 (p<0.001) at the 3-month follow-up. Conclusion: Endovascular revascularization constitutes a safe and feasible treatment modality to restore erectile function in patients with arteriogenic ED and ineffective conservative management. Early elastic recoil is very frequent subsequent to balloon dilation of small-caliber erection-related arteries. Thus, mechanical scaffolding with DES is required in a high subset of ED patients to provide favorable early angiographic and clinical results.

Three-Year Outcomes of Surgical Versus Endovascular Revascularization for Critical Limb Ischemia: The SPINACH Study (Surgical Reconstruction Versus Peripheral Intervention in Patients With Critical Limb Ischemia)

Supplemental Digital Content is available in the text.

Background—

The aim of this study was to compare clinical outcomes between surgical reconstruction and endovascular therapy (EVT) for critical limb ischemia (CLI) in today’s real-world settings.

Methods and Results—

This multicenter, prospective, observational study registered and followed 548 Japanese CLI patients. The registration was in advance of revascularization; 197 patients were scheduled to receive surgical reconstruction, and the remaining 351 were scheduled to receive EVT. The primary end point was 3-year amputation-free survival, compared between the 2 treatments in an intention-to-treat manner, using propensity score matching. Interaction analysis was additionally performed to explore which subgroups had better outcomes with surgical reconstruction or EVT. After propensity score matching, the 3-year amputation-free survival was not significantly different between the 2 groups (52% [95% confidence interval, 43%–60%] and 52% [95% confidence interval, 44–60%]; P=0.26). Subsequent interaction analysis identified (1) Wound, Ischemia, and foot Infection (WIfI) classification W-3, (2) fI-2/3, (3) history of ipsilateral minor amputation, (4) history of revascularization after CLI onset, and (5) bilateral CLI as the factors more favorable for surgical reconstruction, whereas (1) diabetes mellitus, (2) renal failure, (3) anemia, (4) history of nonadherence to cardiovascular risk management, and (5) contralateral major amputation were as those less favorable for surgical reconstruction.

Conclusions—

The 3-year amputation-free survival was not different between surgical reconstruction and EVT in the overall CLI population. The subsequent interaction analysis suggested that there would be a subgroup more suited for surgical reconstruction and another benefiting more from EVT.

Clinical Trial Registration—

URL: http://www.umin.ac.jp/ctr/. Unique identifier: UMIN000007050.

Safety and Feasibility of Intravascular Lithotripsy for Treatment of Below-the-Knee Arterial Stenoses

Purpose: To evaluate the safety and feasibility of treating calcified infrapopliteal stenoses using an intravascular lithotripsy (IVL) system. Methods: The Disrupt BTK study was a prospective, nonrandomized, multicenter, feasibility, and safety trial that enrolled 20 patients (mean age 79.0±9.6 years; 14 men) at 3 participating sites (ClinicalTrials.gov identifier NCT02911623). Fifteen patients had Rutherford category 5 ischemia, and all patients had moderate to severe below-the-knee arterial calcification. Patients were treated with the Shockwave Medical Peripheral IVL System and followed for 30 days. The primary safety endpoint was a composite of major adverse events through 30 days defined as death, myocardial infarction, need for emergency surgical revascularization of the target limb, or amputation of the target limb. The primary effectiveness outcome was acute reduction in the percent diameter stenosis. Results: IVL catheter delivery was successful in 19 patients. The composite of major adverse events at 30 days was 0%. The acute reduction in percent diameter stenosis of target lesions was 46.5%. All patients achieved residual diameter stenosis ≤50%. Vascular complications were minimal with only 1 type B dissection reported and 2 stents placed. None of the subjects experienced thrombus formation, abrupt closure, distal embolization, or perforation. There were no device-related complications. Conclusion: The early results of this pilot study demonstrated that calcified, stenotic infrapopliteal arteries can be safely and successfully treated with intravascular lithotripsy.

Recombinant Human Elastase Alters the Compliance of Atherosclerotic Tibial Arteries After Ex Vivo Angioplasty

Supplemental Digital Content is Available in the Text.

Purpose:

This study was designed to determine whether vonapanitase (formerly PRT-201), a recombinant human elastase, treatment can fragment the protein elastin in elastic fibers and cause dilation of atherosclerotic human peripheral arteries subjected to ex vivo balloon angioplasty.

Materials and Methods:

Seven patients undergoing lower limb amputation for peripheral artery disease or who died and donated their bodies to science donated 11 tibial arteries (5 anterior, 6 posterior) for this study. All arteries were atherosclerotic by visual inspection. The arteries underwent ex vivo balloon angioplasty and thereafter were cut into rings and studied on wire myographs where the rings were stretched and tension was recorded. After treatment with vonapanitase 2 mg/mL or vehicle control, myography was repeated and the rings were then subject to elastin content measurement using a desmosine radioimmunoassay and elastic fiber visualization by histology. The wire myography data were used to derive compliance, stress-strain, and incremental elastic modulus curves.

Results:

Vonapanitase treatment reduced elastin (desmosine) content by 60% and decreased elastic fiber histologic staining. Vonapanitase-treated rings experienced less tension at any level of stretch and as a result had shifts in the compliance and stress-strain curves relative to vehicle-treated rings. Vonapanitase treatment did not alter the incremental elastic modulus curve.

Conclusions:

Vonapanitase treatment of atherosclerotic human peripheral arteries after ex vivo balloon angioplasty fragmented elastin in elastic fibers, decreased tension in the rings at any level of stretch, and altered the compliance and stress-strain curves in a manner predicting arterial dilation in vivo. Based on this result, local treatment of balloon angioplasty sites may increase blood vessel diameter and thereby improve the success of balloon angioplasty in peripheral artery disease.

Comparative Effectiveness of Plain Balloon Angioplasty, Bare Metal Stents, Drug-Coated Balloons, and Drug-Eluting Stents for the Treatment of Infrapopliteal Artery Disease: Systematic Review and Bayesian Network Meta-analysis of Randomized Controlled Trials

PURPOSE

To report a Bayesian network meta-analysis of randomized controlled trials (RCTs) comparing bare metal stents (BMS), paclitaxel-coated balloons (PCBs), and drug-eluting stents (DES) with balloon angioplasty (BA) or with each other in the infrapopliteal arteries.

METHODS

Sixteen RCTs comprising 1805 patients with 1-year median follow-up were analyzed. Bayesian random effects binomial models were employed (WinBUGS). Relative treatment effects were expressed as odds ratios (ORs) with 95% credible intervals (CrI), and the cumulative rank probabilities were calculated to provide hierarchies of competing treatments. Quality of evidence (QoE) was assessed with the GRADE (grading of recommendations assessment, development, and evaluation) system. Sensitivity, heterogeneity, and consistency analyses were performed.

RESULTS

There was high QoE that infrapopliteal DES significantly reduced restenosis compared with BMS (OR 0.26, 95% CrI 0.12 to 0.51) and BA (OR 0.22, 95% CrI 0.11 to 0.45). Likewise, DES significantly reduced target lesion revascularization (TLR) compared with BA (OR 0.41, 95% CrI 0.22 to 0.75) and BMS (OR 0.26, 95% CrI 0.15 to 0.45). Paclitaxel-coated balloons also reduced TLR compared with BA (OR 0.55, 95% CrI 0.34 to 0.90) and BMS (OR 0.35, 95% CrI 0.18 to 0.67), but QoE was low to moderate. BA had lower TLR than BMS (OR 0.63, 95% CrI 0.40 to 0.99) with high QoE. DES was the only treatment that significantly reduced limb amputations compared with BA (OR 0.58, 95% CrI 0.35 to 0.96), PCB (OR 0.51, 95% CrI 0.26 to 0.98), or BMS (OR 0.38, 95% CrI 0.19 to 0.72) with moderate to high QoE. DES also significantly improved wound healing compared with BA (OR 2.02, 95% CrI 1.01 to 4.07) or BMS (OR 3.45, 95% CrI 1.41 to 8.73) with high QoE. Results were stable on sensitivity and meta-regression analyses without any significant publication bias or inconsistency.

CONCLUSION

Infrapopliteal DES were associated with significantly lower rates of restenosis, TLR, and amputations and improved wound healing compared to BA and BMS. DES also significantly reduced amputations compared with PCB.

Key Concepts in Critical Limb Ischemia: Selected Proceedings from the 2015 Vascular Interventional Advances Meeting

Over 500,000 patients each year are diagnosed with critical limb ischemia (CLI), the most severe form of peripheral artery disease. CLI portends a grim prognosis; half the patients die from a cardiovascular cause within 5 years, a rate that is 5 times higher than a matched population without CLI. In 2014, the Centers for Medicare and Medicaid Services paid approximately $3.6 billion for claims submitted by hospitals for inpatient and outpatient care delivered to patients with CLI. Although significant advances in diagnosis, treatment, and follow-up of patients with CLI have been made, many challenges remain. In this article, we summarize selected presentations from the 2015 Vascular Interventional Advances Conference related to the modern demographics, diagnosis, and management of patients with CLI.

Use of Tapered Balloons to Recanalize Occluded Below-the-Knee Arteries in Diabetic Patients with Critical Limb Ischemia

BACKGROUND

The aim of this study was to evaluate the outcome of tapered balloon use in recanalization of long occlusions of below-the-knee (BTK) arteries in diabetic patients with critical limb ischemia (CLI).

METHODS

Forty-nine occluded BTK arteries in 35 diabetic patients with CLI were revascularized in our Diabetic Foot Center between January and September 2014 using tapered balloons. Twelve-month outcomes were evaluated in terms of healing of the lesions, survival, limb salvage, primary patency, primary assisted patency, and secondary patency.

RESULTS

The patients were predominantly male (27/35, 77.1%) with a mean age of 70.9 years (±10.3 standard deviation [SD]). During the follow-up (mean duration 12.4 months ± 4 SD), healing of the lesions was obtained in 27 of the 35 cases (77.1%). Estimated 12-month survival and limb salvage were 85.7% and 91.1%, respectively. Estimated 12-month primary patency, primary assisted patency, and secondary patency were 78.3%, 79%, and 88.9%, respectively. Univariate analysis demonstrated that the presence of chronic renal failure affected survival (P = 0.005), and assignment to Rutherford class 6 affected limb salvage (P = 0.005), primary patency (P < 0.001), and primary assisted patency (P < 0.001). Furthermore, the presence of coronary artery disease affected primary patency (P = 0.001) and primary assisted patency (P = 0.05).

CONCLUSIONS

Tapered balloons are a safe and effective means to recanalize long occlusions of BTK arteries in diabetic patients with CLI. Outcomes are poorer in patients with major tissue loss and with a history of coronary artery disease. Further experience with larger groups is needed to validate these outcomes.

Lesion Pattern in Patients With Erectile Dysfunction of Suspected Arterial Origin

Purpose: To determine the specific lesion pattern of supplying arteries in patients with cardiovascular risk factors suffering from treatment-refractory erectile dysfunction (ED). Methods: From May 2012 to August 2013, 26 men (median age 55 years) poorly responsive to phosphodiesterase-5 inhibitor therapy were evaluated for a possible vascular cause for their ED. The men were examined with penile duplex sonography and digital subtraction angiography (DSA). Arterial lesions in the common and internal iliac arteries and the internal pudendal arteries considered amenable to endovascular therapy were treated with angioplasty ± stents. Retrospectively, 2 blinded investigators independently evaluated the DSA images and categorized the vascular patterns of the erection-related arteries as normal, macroangiopathy (occlusive lesions of the internal pudendal arteries), or microangiopathy (smaller caliber arteries distal to the internal pudendal circulation with no distal arterial reconstitution). Results: Seventeen macroangiopathic lesions were successfully treated by angioplasty in 11 patients. The treated arterial lesions were mainly located in the internal (n=10) and common iliac arteries (n=2), whereas the internal pudendal artery were involved in 5 cases. Microangiopathic lesions lacking distal reconstitution were present in 7 patients, and the remaining 8 patients had normal vessels supplying the penis. Patients with macroangiopathy undergoing angioplasty had a higher prevalence of peripheral artery disease (63.6% vs 6.7%, p=0.003). Conclusion: In this preliminary series of ED patients with cardiovascular risk factors and pathologic duplex sonographic flow parameters, roughly 40% exhibited arterial lesions amenable to endovascular revascularization. In the patients with macroangiopathy, vessels upstream of the internal pudendal artery were most commonly affected. More studies are warranted to define the role of endovascular procedures in this ED subpopulation.

Primary Self-EXPANDing Nitinol Stenting vs Balloon Angioplasty With Optional Bailout Stenting for the Treatment of Infrapopliteal Artery Disease in Patients With Severe Intermittent Claudication or Critical Limb Ischemia (EXPAND Study)

Purpose: To compare primary placement of a self-expanding nitinol stent to percutaneous transluminal angioplasty (PTA) with bailout stenting in infrapopliteal arteries of patients with severe intermittent claudication or critical limb ischemia (CLI). Methods: In the EXPAND trial ( ClinicalTrials.gov; identifier NCT00906022), 92 patients (mean age 72.9±9.5 years; 62 men) undergoing treatment for infrapopliteal stenosis in 11 European centers were randomized 1:1 to either self-expanding nitinol stenting with the Astron Pulsar/Pulsar-18 nitinol stent or PTA with bailout stenting. The primary endpoint was sustainable clinical improvement after 12 months, defined as a ≥1-category increase for Rutherford category 3 patients or a ≥2-category increase for CLI patients (Rutherford categories 4/5) compared with baseline. Furthermore, target lesion revascularization (TLR), mortality, and amputation were assessed after 12 months. Results: Sustained clinical improvement at 1 year was observed in 74.3% of the patients treated with primary stenting and in 68.6% of the patients treated with PTA and bailout stenting (p>0.05). Kaplan-Meier estimates of freedom from TLR (76.6% and 77.6%), mortality (7.4% vs 2.1%), and amputation [8.9% (major 6.7%) vs 13.2% (major 8.7%)] at 1 year were not significantly different. Conclusion: Primary self-expanding nitinol stenting did not show statistically different clinical outcomes compared to angioplasty with bailout stenting for infrapopliteal lesions.

Paclitaxel Drug-eluting Balloons to Recurrent In-stent Stenoses in Autogenous Dialysis Fistulas: A Retrospective Study

Purpose

To assess the effect of the Medtronic paclitaxel drug-eluting balloon (DEB) on re-intervention to in-stent stenoses in autogenous dialysis arteriovenous fistulas (AVFs).

Background

AVF is the optimum haemodialysis access. The commonest problem is stenosis, preventing maturation, causing inadequate dialysis or precipitating occlusion. Conventional angioplasty has a high recurrence rate. Successful drug elution in the coronary circulation led us to use DEBs in recurrent AVF stenoses since 2010.

Methods

This is a retrospective study, based on prospective audit data, using DEBs on recurrent in-stent stenotic lesions in the AVF circuit of our haemodialysis population. To analyse the effect of DEBs on re-intervention, we created two Kaplan–Meier curves. The first curve compares the last “disease-free-interval” pre-DEB intervention to the first “disease-free interval” post-DEB, giving us “re-intervention-free percentage at 12 months” pre- and post-DEB. The second curve takes into account the multiple pre- and post-DEB interventions to the index lesion, and uses a marginal proportional hazards model to estimate the hazard ratio for “DEBpresent vs. DEBabsent”.

Results

From 1 September 2010 to 1 December 2013, we treated 625 AVF stenoses with endovascular techniques. In 86 of these stenoses, DEBs were used. Of the 86 DEB interventions, 37 were included for this study, 49 were excluded. In the study group, there was a significant difference in “re-intervention-free percentage at 12 months” before and after DEB: 19% vs. 69%. The hazard ratio for “DEBpresent” vs. “DEBabsent” was 0.23 (95% CI 0.14 to 0.36, p<0.001).

Conclusions

This retrospective study suggests that DEBs significantly reduce re-intervention on recurrent in-stent AVF stenoses.

The Importance of Patency in Patients with Critical Limb Ischemia Undergoing Endovascular Revascularization for Infrapopliteal Arterial Disease

Critical limb ischemia (CLI) represents the most severe form of peripheral arterial disease (PAD) and frequently occurs in medically frail patients. CLI patients frequently exhibit multi-segmental PAD commonly including the tibial arterial segment. Endovascular therapy has been established as first-line revascularization strategy for most CLI patients. Restenosis was reported to occur in up to more than two-thirds of CLI patients undergoing angioplasty of complex tibial arterial obstructions. Nevertheless, favorable clinical outcomes were observed for infrapopliteal angioplasty when compared with bypass surgery, despite higher patency rates for the latter. Based on these observations, infrapopliteal patency was considered to be only of secondary importance upon clinical outcomes in CLI patients. In contrast to these earlier observations, however, recent findings from two randomized clinical trials indicate that infrapopliteal patency does impact on clinical outcomes in CLI patients. The purpose of the present manuscript is to provide a critical reappraisal of the present literature on the clinical importance of tibial arterial patency in CLI patients undergoing endovascular revascularization and to discuss utility and limitations of currently available anti-restenosis technologies.

Use of the Wallstent for infrapopliteal arterial disease and varying vessel diameters

There is little description of the Wallstent to treat infrapopliteal arterial disease. This may be a viable option due to its high conformability and ability to elongate in vessels of varying diameters. This case report highlights its use in this clinical situation.

Does patency matter in patients with critical limb ischemia undergoing endovascular revascularization?

Restenosis is the major drawback in patients undergoing tibial angioplasty. In contrast to earlier observations, tibial patency was shown to impact on clinical outcomes in current randomized trials and is thus attributed more importance. Accordingly, intentions to reduce tibial restenosis have been intensified. Both drug-eluting balloons (DEB) and drug-eluting stents (DES) were shown to reduce tibial restenosis when compared with its plain counterparts. However, both endovascular technologies have its limitations for tibial arterial application. While DEB technology may not address elastic recoil, a pathophysiological mechanism frequently observed in tibial arteries and a significant contributor to restenosis, currently available DES do not fully address tibial arterial lesion morphology. Purpose of the present manuscript is to outline the problem and the incidence of tibial arterial restenosis, its importance on clinical outcomes and to provide an overview on technical developments aimed at its prevention.