Contemporary Systematic Review and Meta-Analysis of Early Outcomes with Percutaneous Treatment for Infrapopliteal Atherosclerotic Disease

Concomitant Pedal Interventions Improve Outcomes for Tibial Interventions in Chronic Limb-Threatening Ischemia

BACKGROUND

Tibial interventions for chronic limb-threatening ischemia (CLTI) are now commonplace, and poor pedal runoff is associated with worse outcomes. This study aimed to examine the impact of pedal interventions to improve poor pedal runoff on the outcomes following tibial interventions.

METHODS

A database of patients undergoing tibial interventions for CLTI at a single center between 2010 and 2022 was retrospectively queried. Patients with critical ischemia (Rutherford 5 and 6) were identified. Preintervention and postintervention angiograms were reviewed in all cases to assess pedal runoff (total = 10), resulting in 2 run-off score groups as follows: good versus poor, <7 and ≥ 7, respectively. The presence or absence of a pedal intervention then segmented the poor runoff group. Outcomes of wound healing at 3 months, amputation-free survival (AFS; survival without major amputation) and freedom from major adverse limb events (MALE; above ankle amputation of the index limb or major reintervention (new bypass graft and jump or interposition graft revision) were evaluated.

RESULTS

1,768 patients (63% male, age 67 ± 12 years, mean ± SD) with CLTI underwent isolated tibial intervention on a median of 2 tibial vessels. All patients had Wound, Ischemia, and foot Infection (WIfI) grade 3 and 4 disease. Preoperatively, 40% of cases had good runoff (4.4 ± 1.1, mean ± SD), 38% had poor runoff and no pedal intervention (8.6 ± 0.8; P = 0.01 compared to good runoff), and 22% had poor runoff with a concomitant pedal intervention (8.7 ± 0.6; P = 0.01 compared to good runoff). Pedal intervention was performed on a median of 2 tarsal vessels with a technical success of 91% and overall improved pedal runoff (6.5 ± 2.1; P = 0.01 vs. preoperative). Patients with a successful concomitant pedal intervention had improved 30-day MALE rate (7% vs. 12%; P = 0.001) and 30-day amputation rate (5% vs. 11%; P = 0.001) compared to the poor runoff and no pedal intervention group and were comparable to the good runoff and no pedal intervention group (7% and 5%, respectively). Ulcer healing at 3 months was improved in the poor runoff group with intervention (55%) compared to the poor runoff and no pedal intervention group (25%; P = 0.001) but remained significantly below the good runoff group (73%). At 5 years in patients with poor runoff, pedal intervention improved freedom from MALE (41 ± 8% vs. 17 ± 8% mean ± standard error of the mean (SEM); P = 0.008) and AFS (38 ± 6% vs. 11 ± 6%, mean ± SEM; P = 0.003) and these were equivalent to the good runoff group (46 ± 4% and 51 ± 5%, mean ± SEM; freedom from MALE and AFS, respectively).

CONCLUSION

Concomitant pedal intervention to improve pedal runoff in patients with poor pedal runoff during a tibial intervention for CLTI results in improved short-term and long-term outcomes and should be considered for effective limb salvage.

Retrievable Scaffold Therapy Combined with Sirolimus-coated Balloon Angioplasty for Infrapopliteal Artery Disease: Final Results from the DEEPER LIMUS Trial

PURPOSE

To evaluate the safety and efficacy of retrievable scaffold therapy combined with sirolimus-coated balloon angioplasty for treating infrapopliteal artery lesions.

METHODS

The DEEPER LIMUS study enrolled Rutherford class 3 to 5 patients with infrapopliteal artery disease. Patients underwent vessel preparation with retrievable scaffold therapy followed by sirolimus-coated balloon angioplasty. The primary safety outcome measure was a composite of all-cause mortality, major amputation, or clinically driven target lesion revascularization at 6 months. Secondary outcome measures included acute vessel recoil, perioperative death, angiographic late lumen loss between post-procedure and 6 months, as well as primary patency, major amputation, change in Rutherford class, and wound healing through 12 months.

RESULTS

The study included 26 patients (mean age 71 years, 62% male, 88% Rutherford 5) with 28 treated infrapopliteal lesions (36% occluded, 54% TASC B/C). Acute vessel recoil, measured in seven patients, was negligible (2.4 mm after treatment vs. 2.3 mm 15 minutes after deployment). A 6-month primary safety event occurred in 11.5% of patients (1 all-cause mortality, 1 major amputation, 1 clinically driven target lesion revascularization). Late lumen loss at 6 months was 0.7±0.7 mm. At 12 months, primary patency was 89.5%, improvement in Rutherford class was observed in 68.2% of patients, 90% of patients were deemed very low/low major limb amputation risk based on Wound, Ischemia, and foot Infection (WIfI) scores, and no additional major amputations or clinically driven target lesion revascularizations were reported.

CONCLUSIONS

Retrievable scaffold therapy combined with sirolimus-coated balloon angioplasty demonstrated promising safety and efficacy through 12 months in patients with infrapopliteal artery disease.

LEVEL OF EVIDENCE IV

Case Series.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Current Status of and Future Prospects for Drug-Eluting Stents and Scaffolds in Infrapopliteal Arteries

Background: Chronic limb-threatening ischaemia can be a debilitating disease and may result in limb amputation if untreated. Atherosclerotic disease of the infra-popliteal arteries is particularly challenging to treat due to the small caliber of the vessels and the heavy burden of atherosclerotic plaque. Percutaneous transluminal angioplasty is the conventional first-line approach and is advantageous due to its minimal invasiveness, repeatability, and cost-effectiveness but is limited by high rates of elastic recoil, dissection, and short- to mid-term re-stenosis. Methods: This review analyses the growing body of published and presented clinical data from multiple randomised controlled trials that have investigated the role of coronary drug-eluting stents in the treatment of infrapopliteal disease. Results: Coronary drug-eluting stents demonstrate superior primary patency compared with angioplasty and/or bare metal stenting alone but are limited to application in short-segment disease and have not been widely adopted due to the nature of the permanent implant. Conclusions: Newer devices like drug-eluting resorbable scaffolds are promising as they allow the restoration of vessel wall vasomotion without a residual foreign body and can be used to treat longer, complex lesions.

Use of Rotational Atherectomy-Assisted Balloon Angioplasty in the Treatment of Isolated Below-the-Knee Atherosclerotic Lesions in Patients with Chronic Limb-Threatening Ischemia

The aim of the study is to evaluate the safety and effectiveness of rotational atherectomy-assisted balloon angioplasty (BTK-RA) for the treatment of isolated below the knee (BTK) atherosclerotic lesions and to compare the outcomes to plain old balloon angioplasty (POBA). Between January 2020 and September 2023, 96 consecutive patients with chronic limb threatening ischemia (CTLI) and isolated BTK-lesions underwent POBA (group A) or BTK-RA (group B). The primary outcome measures were: periprocedural technical success, primary patency, postoperative increase of the ankle branchial index (ABI), target lesion revascularization (TLR), limb salvage, minor amputation and death. Both techniques had similar technical success, operative time, intraprocedural complications and bailout stent implantations, independently of the operator's experience. Group B had significantly higher primary patency rates (93.5% vs. 72.0%, respectively, p = 0.006), TLR (2.1% vs. 24%, p = 0.057), lower in-hospital stay (2.0-3.0 vs. 4.0-6.0 days, respectively, p < 0.001) and higher postoperative ABI (0.8-0.2 vs. 0.7-0.1, respectively, p = 0.008), compared to group A. Significant differences (POBA n: 20, 40%, BTK-RA n = 3, 6.5%) were found in minor amputation rates between the two groups (p < 0.001), while the respective limb salvage rates were similar in both groups (94.0% vs. 97.8%, p = 0.35). The use of BTK-RA for the treatment of BTK-lesions in patients with CTLI showed significant clinical advantages in comparison to POBA.

How I do it: optimizing angioplasty using the Tack endovascular system in the management of chronic limb threatening ischemia

Dissection occurring after percutaneous transluminal angioplasty (PTA) is associated with decreased vessel patency and an increased incidence of target lesion revascularization. Management of post-PTA dissection with the Tack Endovascular System (Philips, N.V., Amsterdam, Netherlands) has created an effective and durable treatment strategy for infrainguinal dissections. In this report, we discuss the indications and optimal methods for using Tack devices in post-PTA dissections.

Specialty Balloons for Vessel Preparation During Infrainguinal Endovascular Revascularization Procedures: A Review of Literature

Balloon angioplasty with/without utilizing drug eluting technology or stenting constitutes the treatment of choice for a significant percentage of patients with peripheral artery disease requiring an intervention. However, in cases of diffuse disease and plaque complexity, angioplasty may lead to dissection, recoil, and/or early restenosis, making vessel preparation a key component for successful and durable endovascular revascularization outcome. This review of literature aims to present contemporary data for several commercially available specialty balloons that have been designed to minimize the arterial wall stress of conventional balloon angioplasty and facilitate technical success, as well as long-term patency.

KANK4 Promotes Arteriogenesis by Potentiating VEGFR2 Signaling in a TALIN-1-Dependent Manner

BACKGROUND

Arteriogenesis plays a critical role in maintaining adequate tissue blood supply and is related to a favorable prognosis in arterial occlusive diseases. Strategies aimed at promoting arteriogenesis have thus far not been successful because the factors involved in arteriogenesis remain incompletely understood. Previous studies suggest that evolutionarily conserved KANK4 (KN motif and ankyrin repeat domain-containing proteins 4) might involve in vertebrate vessel development. However, how the KANK4 regulates vessel function remains unknown. We aim to determine the role of endothelial cell-specifically expressed KANK4 in arteriogenesis.

METHODS

The role of KANK4 in regulating arteriogenesis was evaluated using Kank4^-/- and KANK4^iECOE mice. Molecular mechanisms underlying KANK4-potentiated arteriogenesis were investigated by employing RNA transcriptomic profiling and mass spectrometry analysis.

RESULTS

By analyzing Kank4-EGFP reporter mice, we showed that KANK4 was specifically expressed in endothelial cells. In particular, KANK4 displayed a dynamic expression pattern from being ubiquitously expressed in all endothelial cells of the developing vasculature to being explicitly expressed in the endothelial cells of arterioles and arteries in matured vessels. In vitro microfluidic chip-based vascular morphology analysis and in vivo hindlimb ischemia assays using Kank4^-/- and KANK4^iECOE mice demonstrated that deletion of KANK4 impaired collateral artery growth and the recovery of blood perfusion, whereas KANK4 overexpression leads to increased vessel caliber and blood perfusion. Bulk RNA sequencing and Co-immunoprecipitation/mass spectrometry (Co-IP/MS) analysis identified that KANK4 promoted EC proliferation and collateral artery remodeling through coupling VEGFR2 (vascular endothelial growth factor receptor 2) to TALIN-1, which augmented the activation of the VEGFR2 signaling cascade.

CONCLUSIONS

This study reveals a novel role for KANK4 in arteriogenesis in response to ischemia. KANK4 links VEGFR2 to TALIN-1, resulting in enhanced VEGFR2 activation and increased EC proliferation, highlighting that KANK4 is a potential therapeutic target for promoting arteriogenesis for arterial occlusive diseases.

MagicTouch PTA Sirolimus Coated Balloon for Femoropopliteal and Below the Knee Disease: Results From XTOSI Pilot Study Up To 12 Months

INTRODUCTION

Sirolimus coated balloon (SCB) is a promising treatment option to prevent restenosis for peripheral arterial occlusive disease (PAOD). This is a pilot first-in-human study of MagicTouch percutaneous transluminal angioplasty (PTA) SCB for treatment of PAOD for both femoropopliteal and below the knee arteries (BTK).

MATERIAL AND METHODS

Xtreme Touch-Neo [MagicTouch PTA] Sirolimus Coated Balloon (XTOSI) pilot study is a prospective, single-arm, open-label, single-center trial evaluating MagicTouch PTA SCB for symptomatic PAOD. Primary endpoint was defined as primary patency at 6 months (duplex ultrasound peak systolic velocity ratio ≤2.4). Secondary endpoints included clinically driven target lesion revascularization (CD-TLR), amputation free survival (AFS), all-cause mortality, and limb salvage success.

RESULTS

Fifty patients were recruited. The mean age was 67 (n=31 [62%] males). SCB was applied to femoropopliteal in 20 patients (40%) and BTK in 30 patients (60%). Majority of treatments (94%) were performed for limb salvage indications (Rutherford scores 5 or 6). This was a high risk cohort, in which 90% had diabetes, 36% had coronary artery disease, 20% had end stage renal failure, and American Society of Anaesthesiologists (ASA) score was 3 or more in 80%. Mean lesion length treated was 227±81 mm, of which 36% were total occlusions. Technical and device success were both 100%. At 30 days, mortality was 2% and major limb amputation was also 2%. Six-month primary patency was 80% (88.2% for femoropopliteal; 74% for BTK). At 12 months, freedom from CD-TLR was 89.7% (94.1% for femoropopliteal; 86.3% for BTK), AFS was 81.6% (90.0% for femoropopliteal; 75.9% for BTK), all-cause mortality was 14.3% (10.0% for femoropopliteal; 17.2% for BTK), and limb salvage success was 92.9% (94.4% for femoropopliteal; 91.7% for BTK). There was a statistically significant increase between baseline and 6-month toe pressures for both femoropopliteal (57.3±23.3 mm Hg vs 82.5±37.8 mm Hg; p<.001) and BTK lesions (52.8±19.2 mm Hg vs 70.7±37 mm Hg; p<.037). At 12 months, wound healing rate was 33/39 (84.6%).

CONCLUSIONS

MagicTouch PTA SCB in the XTOSI study showed promising 6-month primary patency and encouraging 12-month freedom from CD-TLR, AFS, and limb salvage rates. No early safety concerns were raised. Randomized trials are needed to investigate the safety and efficacy of SCB for treatment of PAOD.

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.

Device profile of the tack endovascular system® for the treatment of peripheral arterial disease: overview of safety and efficacy

Introduction: The 6 F Tack Endovascular System® is approved by the United States Food and Drug Administration (FDA) for post-percutaneous transluminal angioplasty (PTA) dissection repair in the superficial femoral and proximal popliteal arteries, and the 4 F System for post-PTA dissection repair in the mid/distal popliteal, peroneal and tibial arteries. The latter is the first FDA approval for an infra-popliteal implantable device.Areas covered: An evaluation of the Tack Endovascular System® design and a summary of the current safety and efficacy data.Expert opinion: Endovascular intervention for the treatment of symptomatic peripheral arterial disease (PAD) in the lower extremities is complicated by long-lesion length, extensive calcification and, below the knee, narrow vessel diameter. PTA is a foundational element for the treatment of these lesions and works by causing a controlled dissection and vessel expansion of the target lesion. Occasionally, dissections can extend beyond the target lesion and/or become hemodynamically significant due to lumen impingement necessitating additional intervention. Historically these dissections were treated with the use of stents, prolonged balloon inflation time or went untreated. The Tack Endovascular System® was designed to provide operators a safe and effective device which could repair post-PTA dissections while preserving future treatment options.

Management of Complications during Below-the-Knee Endovascular Treatment: A Technical Note

We retrospectively reviewed the cases in which complications occurred during below-the-knee (BTK) endovascular treatments that were performed at our hospital from 2005 to 2014. Several interesting cases have been described herein. All the patients had diabetes and non-healing wounds on their feet and/or rest pain in their foot or leg, and therefore, endovascular treatment was performed for the BTK arteries of the affected lower extremity. The complications that occurred during the procedure were classified into six categories-vascular spasm, flow limiting dissection, perforation, broken guidewire, distal thromboembolism, and unusual puncture site bleeding. Each complication has its own solutions and management. We discuss these different classes of complications and describe how cases of each type were managed.

Six-month pivotal results of tack optimized balloon angioplasty using the Tack Endovascular System in below-the-knee arteries

OBJECTIVE

No vascular implant is commercially available in the United States to treat post-angioplasty dissections in below-the-knee (BTK) arteries. The Tack Endovascular System (Intact Vascular, Wayne, Pa) is purpose-built to repair postpercutaneous transluminal angioplasty (PTA) BTK dissections. A trial was conducted to investigate the safety and efficacy of the first-of-a-kind implantable BTK device to treat post-PTA dissections in the setting of critical limb ischemia.

METHODS

The present prospective, single-arm, multicenter study evaluated the Tack Endovascular System for treating post-PTA dissections in the mid/distal popliteal, tibial, and peroneal arteries. The primary safety endpoint was major adverse limb events (MALE) plus perioperative death (POD), assessed at 30 days after the index procedure. The primary efficacy endpoint was a composite of MALE at 6 months and POD. The unpowered secondary endpoint was primary patency at 6 months. With no available on-label comparator, the primary endpoints of the present trial were determined using objective performance goals from a systematic literature search. The secondary endpoints included Tacked segment patency and target limb salvage at 6 months. The 6-month results are reported.

RESULTS

Of the 233 patients enrolled, 117 (50.2%) had Rutherford class 5 and 78 (33.5%) had Rutherford class 4. A total of 341 post-PTA dissections were treated. Each patient received at least one Tack implant, and 100% of the dissections resolved according to the angiographic core laboratory findings. The primary safety and efficacy endpoints were both met. The rate of MALE plus POD at 30 days was 1.3% (3 of 228) and freedom from MALE at 6 months plus POD at 30 days was 95.6% (196 of 205). The 6-month Tacked segment patency was 82.1% (247 of 301) and target limb salvage was 98.5% (202 of 205). The Kaplan-Meier freedom from clinically driven target lesion revascularization and amputation-free survival at 6 months was 92.0% and 95.7%, respectively. Rutherford improvement was reported in 79.4% (158 of 199). Most (90 of 122; 73.8%) preexisting wounds had healed or were improving.

CONCLUSIONS

The Tack Endovascular System is safe and effective for treating post-PTA BTK dissections through 6 months, with favorable rates of MALE plus POD, patency, clinically driven target lesion revascularization, limb salvage, and wound healing.

Effects of external crushing forces on a novel below-the-knee vascular implant

BACKGROUND

The Tack Endovascular System^® is a novel vascular implant designed to focally treat dissections with low radial force and minimal metal burden. As there are currently no approved below-the-knee (BTK) implants in the USA, a unique, 3-stage model was developed to characterize crush deformation and fracture potential of the Tack Endovascular System in BTK arteries.

METHODS

First, 35 Tack^® implants were deployed bilaterally in the posterior tibial, anterior tibial, and peroneal arteries of 3 cadavers, and clinically relevant external forces were applied to simulate BTK crushing deformation including focal load, leg crossing, and leg bending. Intravascular ultrasound images of the implanted vessels were used to assess the magnitude of artery deformation. Outputs of the cadaver testing were input into a finite element analysis (FEA) model to determine the appropriate conditions for subsequent bench testing. Tack implants were then subjected to increasing crush forces at 30Hz for up to 650,000 cycles at 25% flat plate deformation within the worst-case FEA test condition.

RESULTS

Crush deformation across all arteries ranged from 0% to 23.1%. The posterior tibial artery and large male cadaver exhibited the most vulnerability to external crush forces, while the small female model exhibited the most resistance. No fractures were observed during cadaver or bench testing.

CONCLUSIONS

This study characterized deformation forces in tibial arteries during various loading conditions. Tack implants withstood the loading conditions without fracture within the limits of this ex-vivo human vascular model and in-vitro bench testing.

Twelve-Month Results of Tack-Optimized Balloon Angioplasty Using the Tack Endovascular System in Below-the-Knee Arteries (TOBA II BTK)

Purpose: To report the 12-month safety and efficacy outcomes of the investigational device exemption trial evaluating an implantable below-the-knee (BTK) dissection repair device. Materials and Methods: The prospective, multicenter, single-arm Tack-Optimized Balloon Angioplasty (TOBA) II BTK study (ClinicalTrials.gov identifier NCT02942966) evaluated the Tack Endovascular System in the BTK arteries vs objective performance goals derived from a systematic review of BTK angioplasty literature. Patients presenting with Rutherford category 3-5 ischemia were eligible and were enrolled during the procedure if angioplasty resulted in dissection(s) of the BTK arteries. Between February 2017 and December 2018, the study enrolled 233 patients (mean age 74.4±10.0 years; 157 men). Most lesions (93.8%) were de novo; almost half (118/248, 47.6%) were total occlusions. Mean target lesion length was 80±49 mm. Moderate to severe calcium was present in 89 (35.8%) lesions. The 30-day primary safety endpoint was a composite of major adverse limb events (MALE) and all-cause perioperative death (POD). The primary efficacy endpoint was a composite of MALE at 6 months and 30-day POD. These safety and efficacy endpoints were assessed at 12 months as observational endpoints along with amputation-free survival (AFS), freedom from clinically-driven target lesion revascularization (CD-TLR), vessel patency, and changes from baseline in clinical and quality of life measures. Results: All patients had post-PTA dissection and received at least 1 Tack implant (range 1 to 16). The angiographic core laboratory noted successful resolution of 100% of the 341 treated dissections. At 12 months, 93.4% (170/182) of patients remained free of the composite endpoint of MALE + POD. Tacked segment patency was 81.3% and limb salvage was 96.8% at 12 months; freedom from CD-TLR and AFS were 83.1% and 89.3%, respectively. Sustained Rutherford category improvement was reported in 82.4% of evaluated patients, with 62.4% improving ≥3 categories (p<0.001). Ninety of 124 index wounds (72.5%) healed or improved. Conclusion: The Tack Endovascular System is safe and effective in the treatment of post-angioplasty BTK dissections. Twelve-month outcome data from the TOBA II BTK study demonstrate high rates of patency, limb salvage, and wound healing.

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.

Diagnostic and Therapeutic Approaches in the Management of Infrapopliteal Arterial Disease

Chronic limb-threatening ischemia represents end-stage peripheral artery disease. It is underdiagnosed; it relies on clinical symptoms and traditional noninvasive tests, which significantly underestimate the severity of disease. Innovative techniques, approaches, technologies, and risk-assessment tools have significantly improved our ability to treat these patients and to better understand their complex disease process. For patients with chronic limb-threatening ischemia considered without options, the reengineering of deep venous arterialization procedures has shown promising results. Finally, the creation of interactive and multidisciplinary teams in centers of excellence is of paramount importance to significantly improve the care and outcomes of these patients.

Dissections After Infrainguinal Percutaneous Transluminal Angioplasty: A Systematic Review and Current State of Clinical Evidence

Purpose: To systematically review the literature and extract information on the definitions, prevalence, implications, and treatment of dissections after infrainguinal balloon angioplasty, with a goal of summarizing current data and identifying gaps in knowledge to help direct future research. Materials and Methods: A systematic review was performed according to the PRISMA guidelines. Medline (PubMed), Scopus, and Cochrane CENTRAL databases were reviewed for prospective and retrospective studies reporting dissection identification, characterization, incidence, severity, and/or outcomes after infrainguinal balloon angioplasty up to January 30, 2019. The electronic search resulted in 288 studies. From these, 153 full-text articles were assessed, and 51 published from 1964 to 2018 were selected as relevant to this systematic review. Because of the significant between-study differences in lesion characteristics, reporting methods, and lack of core laboratory adjudication, the findings were summarized from each study, but the results were not pooled. Results: The mechanism of percutaneous transluminal angioplasty (PTA) consists of adventitial stretching, medial necrosis, and controlled dissection or plaque fracture. PTA-induced dissections can precipitate pathological high and low shear hemodynamic defects and have been implicated as a contributing factor in procedural complications as well as restenosis at the treatment site. The development of significant dissection after PTA often leads to the use of adjunctive therapies, including stent placement. Despite the ubiquitous nature of dissection after balloon angioplasty (incidence 7.4% to 84%), limited data are available to categorize dissections in the peripheral arteries and direct subsequent treatments to improve vessel patency. With the increased utilization of drug-coated balloon angioplasty, understanding the outcomes of postangioplasty dissection has become increasingly important, as the decision to treat dissections with additional strategies has therapeutic and economic implications. Conclusion: All post-PTA dissections in the femoropopliteal arteries may benefit from a treatment approach that ensures optimal hemodynamics with long-term durability in treated lesions. Further understanding the importance of postangioplasty dissections, along with the development of new technologies, will help optimize the patency of endovascular interventions.

Novel balloon technologies to minimize dissection of peripheral angioplasty

INTRODUCTION

Percutaneous transluminal angioplasty (PTA) currently remains the endovascular treatment of choice in a large percentage of patients suffering from peripheral artery disease (PAD). However, the mechanism of angioplasty itself can cause some extent of arterial dissection leading to early vessel restenosis/reocclusion. Current endovascular imaging studies have reported a higher rate of arterial dissection than previously reported in literature and advocated the correlation of dissection with poor patency. Thus, there is the need of developing devices to minimize dissection and bailout stenting.

AREAS COVERED

The present review focuses on newly-developed balloon angioplasty technologies designed to minimize arterial wall distress and consequently the rate of dissections. Available literature regarding three new specialty balloons is being reviewed, highlighting their value and limitations. Authors' future perspective about the benefits of utilizing specialty balloons towards a metal free and dissection free future is also provided.

EXPERT OPINION

By understanding the mechanism of angioplasty and thus developing devices which cause minimal or no arterial wall distress, the rate of dissections and bailout stenting can be minimized and long-term clinical outcomes of endovascular therapy can be optimized.

Atherectomy in below-the-knee endovascular interventions: One-year outcomes from the XLPAD registry

BACKGROUND

Use of atherectomy for the treatment of peripheral arterial disease (PAD) is increasing as an adjunctive treatment to either conventional or drug-coated balloon angioplasty. There is limited data on atherectomy outcomes in below-the-knee (BTK) endovascular interventions.

METHODS

Data from the multicenter Excellence in Peripheral Artery Disease (XLPAD) registry (NCT01904851) were analyzed to examine predictors of atherectomy use and its associated 1-year patency rate. We analyzed 518 BTK procedures performed between January 2005 and December 2016.

RESULTS

Overall a total of 518 BTK procedures were treated in 430 patients, and 43% of interventions used atherectomy. African American patients were less likely (13% vs 25%; |standard residual| = 3.41) to be treated with atherectomy. Use of atherectomy was lower in chronic total occlusive (CTO) lesions (48% vs 58%; P = 0.02). There were no significant associations of baseline comorbidities, critical limb ischemia (CLI), ankle-brachial index, number of BTK vessel run-off, or vessel location with atherectomy use. Compared with patients without atherectomy, use of atherectomy was associated with lower incidence of repeat target limb intervention at 1 year after adjusting for age, CLI, in-stent restenosis, heavy calcification, presence of diffuse disease, and CTO lesion traits (Hazard Ratio 0.41, 95% confidence interval 0.23-0.72; P < 0.01).

CONCLUSIONS

Compared with no atherectomy, use of atherectomy in BTK interventions is associated with lower rates of 1-year repeat target limb revascularization. These findings require confirmation in prospective, randomized clinical studies.

Effect of hospital volume on outcomes of percutaneous peripheral atherectomy - An observational analysis from National Inpatient Sample

BACKGROUND

Although the published literature has reported an inverse association between hospital volume and outcomes of coronary interventions, sparse data are available for percutaneous peripheral atherectomy (PPA). The aim of our study was to examine the effect of hospital volume on outcomes of PPA.

METHODS

Using the Nationwide Inpatient Sample (NIS) database of the year 2012, PPA with ICD-9 code of 17.56 was identified. The primary outcomes were mortality and amputation rates; secondary outcomes were peri-procedural complications, cost, and length of hospitalization and discharge disposition of the patient. Multivariate models were generated for predictors of the outcomes.

RESULTS

We identified a total of 21,015 patients with mean age of 69.53 years, with 56% males. Higher hospital volume centers were associated with a significantly lower mortality (OR 0.42, 95% CI 0.30-0.57, p < 0.0001), amputation rates (5.34% vs. 9.32%, p < 0.0001), combined endpoint of mortality and complications (OR 0.53, 95% CI 0.49-0.58, p < 0.0001), shorter length of hospital stay (LOS) (4.86 vs. 6.79 days, p < 0.0001) and lower hospitalization cost ($23,062 vs. $30,794, p < 0.0001). Subgroup analysis for acute and chronic limb ischemia showed similar results.

CONCLUSION

Hospital procedure volume is an independent predictor of mortality, amputation rates, complications, LOS, and costs in patients undergoing PPA with an inverse relationship.

Prevention of in-stent restenosis with endothelial progenitor cell (EPC) capture stent placement combined with regional EPC transplantation: An atherosclerotic rabbit model

BACKGROUND

Even with drug-eluting stents, the risk of in-stent restenosis (ISR) remains high. The goal of this study was to investigate the use of an endothelial progenitor cell (EPC) capture stent plus regional EPC transplantation to reduce the ISR rate.

METHODS

Endothelial progenitor cell capture stents were fabricated using fibrin gel and anti-CD34 plus anti-VEGFR-2 dual antibodies. Twenty male New Zealand white rabbits established as an atherosclerotic model were randomly divided into two groups: group 1 (n = 10), in which EPC capture stents were deployed into the right iliac artery; and group 2 (n = 10), in which sirolimus-eluting stents were placed. In both groups, EPCs were transplanted into target vessels beyond the stents, with outflow blocked. Radiologic-pathologic correlation outcomes were reviewed after 2 months.

RESULTS

The technical success rate of EPC capture stent placement plus EPC transplantation was 100%. The ISR rate in group 1 was lower than in group 2 (1/10 vs. 4/10; p > 0.05). Minimal luminal diameters were larger in group 1 than in group 2 (computed tomographic angiography, 1.85 ± 0.15 mm vs. 1.50 ± 0.20 mm; duplex ultrasound, 1.90 ± 0.10 mm vs. 1.70 ± 0.30 mm; p > 0.05). Transplanted EPCs were tracked positively only in group 1. Pathologic analysis demonstrated neointimal hyperplasia thickness of 0.21 ± 0.09 mm in group 1 vs. 0.11 ± 0.07 mm in group 2 (p < 0.05).

CONCLUSION

Endothelial progenitor cell capture stent placement plus local EPC transplant decreases the ISR rate through thrombosis reduction rather than through neointimal hyperplasia inhibition.

Outcomes of reintervention for recurrent symptomatic disease after tibial endovascular intervention

OBJECTIVE

Tibial interventions for critical limb ischemia are now commonplace. Restenosis and occlusion remain barriers to durability after intervention. The aim of this study was to examine the patient-centered outcomes of open and endovascular reintervention for symptomatic recurrent disease after a primary isolated tibial endovascular intervention.

METHODS

A database of patients undergoing isolated primary lower extremity tibial endovascular interventions between 2006 and 2016 was retrospectively queried. Patients with recurrent critical ischemia (Rutherford 4 and 5) were identified. Outcomes in this cohort were analyzed, and three groups were defined: endovascular reintervention (ie, a repeated tibial or pedal endovascular intervention), bypass (bypass to a tibial or pedal vessel), and primary amputation (ie, above- or below-knee amputation) on the ipsilateral leg. Patient-oriented outcomes of clinical efficacy (absence of recurrent signs or symptoms of critical ischemia, maintenance of ambulation, and absence of major amputation), amputation-free survival (survival without major amputation), and freedom from major adverse limb events (above-ankle amputation of the index limb or major reintervention, such as new bypass graft or jump or interposition graft revision) were evaluated after the reintervention.

RESULTS

There were 1134 patients (56% male; average age, 59 years) who underwent primary tibial intervention for critical ischemia, and 54% presented with symptomatic restenosis and occlusion. Of the 513 patients with recurrent disease, 58% presented with rest pain and the remainder with ulceration. A repeated tibial endovascular intervention was performed in 64%, open bypass in 19%, and below-knee amputation in 17%. Bypass was employed in patients with a good target vessel, venous conduit, and good pedal runoff. Patient-centered outcomes were better in the bypass group compared with the reintervention group (amputation-free survival, 45% ± 9% vs 27% ± 9% [P < .01]; major adverse limb events, 50% ± 9% vs 31% ± 9% [P < .05]; clinical efficacy, 60% ± 7% vs 30% ± 9% [P < .01], mean ± standard error of the mean at 5 years).

CONCLUSIONS

Tibial interventions for critical ischemia are associated with a high rate of reintervention. In patients with good target vessel, venous conduit, and good pedal runoff, bypass appears more durable than repeated tibial endovascular intervention.

Outcomes of tibial endovascular intervention in patients with poor pedal runoff

OBJECTIVE

Tibial interventions for critical limb ischemia are now commonplace. The aim of this study was to examine the impact of pedal runoff on patient-centered outcomes after tibial endovascular intervention.

METHODS

A database of patients undergoing lower extremity endovascular interventions at a single urban academic medical center between 2006 and 2016 was retrospectively queried. Patients with critical ischemia (Rutherford 5 and 6) were identified. Preintervention angiograms were reviewed in all cases to assess pedal runoff. Each dorsalis pedis, lateral plantar, and medial plantar artery was assigned a score according to the reporting standards of the Society for Vascular Surgery (0, no stenosis >20%; 1, 21%-49% stenosis; 2, 50%-99% stenosis; 2.5, half or less of the vessel length occluded; 3, more than half the vessel length occluded). A foot score (dorsalis pedis + medial plantar + lateral plantar + 1) was calculated for each foot (1-10). Two runoff score groups were identified: good vs poor, <7 and ≥7, respectively. Patient-oriented outcomes of clinical efficacy (absence of recurrent symptoms, maintenance of ambulation, and absence of major amputation), amputation-free survival (survival without major amputation), and freedom from major adverse limb events (above-ankle amputation of the index limb or major reintervention [new bypass graft, jump/interposition graft revision]) were evaluated.

RESULTS

There were 1134 patients (56% male; average age, 59 years) who underwent tibial intervention for critical ischemia, with a mean of two vessels treated per patient and a mean pedal runoff score of 6 (47% had a runoff score ≥7). Overall major adverse cardiac events were equivalent at 30 days after the procedure in both groups. At 5 years, vessels with compromised runoff (score ≥7) had significantly lower ulcer healing (25% ± 3% vs 73% ± 4%, mean ± standard error of the mean [SEM]) and a lower 5-year limb salvage rate (45% ± 6% vs 69% ± 4%, mean ± SEM) compared with those with good runoff (score <7). Patients with poor pedal runoff (score ≥7) had significantly lower clinical efficacy (23% ± 8% vs 38% ± 4%, mean ± SEM), amputation-free survival (32% ± 6% vs 48% ± 5%, mean ± SEM), and freedom from major adverse limb events (23% ± 9% vs 41% ± 8%, mean ± SEM) at 5 years compared with patients with good runoff (score <7).

CONCLUSIONS

Pedal runoff score can identify those patients who will not achieve ulcer healing and patient-centered outcomes after tibial intervention. Defining such subgroups will allow stratification of the patients and appropriate application of interventions.

Meta-analysis of drug-eluting balloon angioplasty and drug-eluting stent placement for infrainguinal peripheral arterial disease

PURPOSE

To perform a meta-analysis of randomized controlled trials (RCTs) of drug-eluting balloon (DEB) angioplasty and drug-eluting stents (DESs) for infrainguinal peripheral arterial disease.

MATERIALS AND METHODS

Systematic searches were performed for all relevant RCTs.

RESULTS

Eight RCTs for DEB angioplasty and 12 RCTs for a DES in peripheral arterial disease were identified. Meta-analysis demonstrated statistically significant superiority of DEB over plain balloon angioplasty of femoral-popliteal disease for late lumen loss, restenosis, and target lesion revascularization, with no benefit in major amputation or mortality. Statistically significant superiority of DEB over percutaneous transluminal angioplasty (PTA) was demonstrated for infrapopliteal disease for restenosis and target lesion revascularization. Drug-eluting stents showed statistically significant superiority over bare metal stents (BMSs) of femoral-popliteal disease for late lumen loss and restenosis, with no benefit in mortality or amputation. Drug-eluting stents showed statistically significant superiority over BMSs of infrapopliteal disease restenosis and target lesion revascularization, with no benefit in amputation or mortality.

CONCLUSIONS

Drug-eluting balloon angioplasty and DESs demonstrated superior outcomes compared to PTA and BMS, with no difference in amputation or mortality.