Biologic Drug Effect and Particulate Embolization of Drug-Eluting Stents versus Drug-Coated Balloons in Healthy Swine Femoropopliteal Arteries

Impact of Below-the-Knee Runoff in Patients With Lower Extremity Artery Disease Who Underwent Endovascular Therapy Using Drug-Coated Balloons in Femoropopliteal Lesions

BACKGROUND

The impact of below-the-knee (BK) runoff after drug-coated balloon (DCB) treatment in femoropopliteal (FP) lesions has not been well investigated.

METHODS

This retrospective multicenter observational study enrolled 291 consecutive patients with lower extremity artery disease who underwent endovascular therapy with DCBs for FP lesions between January 2018 and December 2021. Patients were classified into four groups based on the BK runoff. Outcome measures included primary patency, freedom from clinically driven target lesion revascularization (CD-TLR) and amputation, and overall survival rates at 24 months. The predictors of restenosis at 24 months were also investigated.

RESULTS

In total, 43, 98, 117, and 33 patients were classified into three, two, one, and no BK runoff groups, respectively. In three, two, one, and no BK runoff groups, the primary patency rates were 72.1%, 67.3%, 61.4%, and 44.1% (p = 0.028); freedom from CD-TLR rates were 87.1%, 78.8%, 71.7%, and 47.1% (p < 0.001); freedom from amputation rates were 95.2%, 97.9%, 92.8%, and 91.5% (p = 0.499); and overall survival rates were 89.4%, 83.2%, 76.6%, and 61.2% (p = 0.007), respectively, at 24 months. Multivariate analysis showed that chronic limb-threatening ischemia, no BK runoff, Lutonix use, and residual stenosis > 30% were independent predictors of primary patency loss at 24 months. The risk score, calculated as the number of predictors, reflected the risk of restenosis.

CONCLUSION

No BK runoff was associated with worse midterm primary patency, freedom from CD-TLR, and overall survival rates than at least one BK runoff.

Moving away from metal: Step toward the future with bioresorbable vascular scaffolds and novel antiproliferative agents

Background

Peripheral arterial disease (PAD) is a common source of morbidity and mortality globally and is expected to raise increase in prevalence. Many endovascular techniques exist to manage PAD; however, there remains room for improvement, especially as it relates to below-the-knee vessels. Recent evidence and devices are leading to a resurgence of interest in bioresorbable vascular scaffolds and the -limus family of antiproliferative drugs in the PAD treatment space.

Methods

This nonsystematic review examines emerging technology for treatment of PAD with a specific focus on below-the-knee vessels and bioresorbable vascular scaffolds. Additional emerging and early technology such as novel delivery platforms are also briefly discussed with directions of future research highlighted.

Results

Bioresorbable vascular scaffold biomechanics and history are highlighted. Foundational knowledge of antiproliferative agents and evolving agents in peripheral vascular disease are also described.

Conclusions

Bioresorbable vascular scaffolds are an additional endovascular tool for the treatment of peripheral vascular disease. The integration with an antiproliferative agent may result in improved patency and performance; however, there is a paucity of data in the literature at present.

Differences in Biologic Drug Effects and Distal Particulate Embolization in Three Paclitaxel-Coated Balloons for Femoropopliteal Lesions in a Rabbit Model

BACKGROUND

A recent meta-analysis of randomized control trials demonstrated a significantly higher risk of major amputation in patients treated with drug-coated balloons (DCBs) compared with standard treatment, especially in high-dose paclitaxel-coated DCBs. Distal particulate embolization after DCB use was considered a potential cause of the higher incidence of major amputation. The current study aimed to histologically and biologically compare biologic drug effect and distal particulate embolization in 3 DCBs (a high-dose paclitaxel-coated DCB [IN.PACT Admiral] and 2 low-dose paclitaxel-coated DCBs [Ranger and Lutonix]).

METHODS AND RESULTS

The DCBs were inflated in the healthy descending aortas of 18 rabbits, followed by euthanasia 28 days after the procedure. The treated descending aorta and distal skeletal muscles were histopathologically evaluated, and paclitaxel concentrations were measured. The paclitaxel concentration of the treated lesion was highest for Ranger, followed by IN.PACT and Lutonix (Ranger vs IN.PACT vs Lutonix: 1089 [745-2170] pmol/mg vs 638 [160-2075] pmol/mg vs 25 [10-304] pmol/mg, respectively; p<0.0001). In the histopathological evaluation, the angle of severe medial smooth muscle cell loss was largest for Ranger followed by IN.PACT and Lutonix (12.8 [8.0-20.4] degree vs 1.4 [1.2-5.2] degree vs 0.8 [0.5-2.5] degree, respectively), with significant differences for Ranger vs IN.PACT (p=0.007) and Ranger vs Lutonix (p=0.002). However, paclitaxel concentrations of distal skeletal muscles were lowest for Lutonix, followed by Ranger and IN.PACT (12 [1-58] pmol/mg vs 15 [13-21] pmol/mg vs 42 [19-108] pmol/mg, respectively, p<0.0001). The numbers of arteries with downstream DCB effects were highest for IN.PACT, followed by Ranger and Lutonix (Ranger vs IN.PACT vs Lutonix, 3 [3-4] vs 4 [3-7] vs 2 [1-2], respectively), which was consistent with the measured tissue paclitaxel concentrations.

CONCLUSION

These findings suggest that Ranger demonstrates the strongest paclitaxel effect, as well as the second-best effect regarding distal particulate embolization, making it a good treatment option for patients with peripheral artery disease among the 3 DCBs evaluated in the current study. Further clinical head-to-head comparisons with larger numbers of patients are needed to explore which DCB is the most effective and safe treatment option.Clinical Impact:The findings of the current preclinical study suggests that Ranger demonstrates the strongest paclitaxel effect, as well as the second-best effect regarding distal particulate embolization making it a good treatment for patients with intermittent claudication and chronic limb-threatening ischemia.

Degradation of a novel magnesium alloy-based bioresorbable coronary scaffold in a swine coronary artery model

The objective of the study is to investigate the safety, feasibility, and degradation profile of a novel Mg alloy-based bioresorbable coronary scaffold (JFK-PRODUCT BRS) with thin struts (110 μm). Polymer- or Mg alloy-based BRSs have not replaced nondegradable metal stents because of the higher prevalence of scaffold thrombosis and restenosis in clinical practice; these poor clinical outcomes were due to inadequate scaffold designs, including thick struts (more than 150 μm) and their inappropriate degradation processes. Fourteen healthy pigs received 17 JFK-PRODUCT BRSs in the coronary arteries and were sacrificed at 1, 6, 12, 18, and 26 months after implantation. Angiography, optical coherence tomography, microfocus X-ray computed tomography (µCT), scanning electron microscopy with energy-dispersive X-ray spectrometry (SEM-EDX), and histopathological evaluation were performed. The JFK-PRODUCT had a median percent late recoil of 11.28% at 1 month. The µCT observation confirmed that scaffold discontinuity reached 64.8% at 12 months with increased scaffold inner area thereafter, suggesting artery positive remodeling. The inflammation was mild, peaked at 18 months, and decreased thereafter. The SEM-EDX analysis demonstrated gradual degradation of the scaffold with formation of inorganic deposits, presumed to be calcium phosphates. It also revealed the disappearance of calcium phosphates at 26 months, achieving almost complete replacement of the scaffold by biocomponents. The current study demonstrated the safety and feasibility of JFK-PRODUCT with a lower acute recoil rate despite its thin struts. The scaffolds were almost completely disappeared at 26 months after implantation.

Efficacy of a novel method: VaSodilator injection via the Over-the-wire lumen during drug-coated balloon dilatation to Prevent the slow-flow phenomenon in treatment of femoropopliteal lesions

In drug-coated balloon (DCB) angioplasty for femoropopliteal lesions, there are adverse effects of drug embolization on downstream non-target organs following the slow-flow phenomenon. We devised a novel method, known as VaSodilator injection via the Over-the-wire lumen during DCB dilatation to Prevent the slow-flow phenomenon in treatment of femoropopliteal lesions (V.S.O.P.), and evaluated its efficacy and safety. This single-center, retrospective, observational study analyzed 196 femoropopliteal lesions treated with IN.PACT Admiral between April 2018 and July 2023. The IN.PACT Admiral is a DCB consisting of a 0.035-inch over-the-wire (OTW) lumen balloon coated with high-dose paclitaxel. Regarding the V.S.O.P. method, we injected vasodilators through the OTW lumen during DCB dilation of the lesions. The cohort was classified into two groups according to the use of the V.S.O.P. method (V.S.O.P. group: n = 53; non-V.S.O.P. group: n = 143). The V.S.O.P. group had lower rates of hemodialysis (21% vs. 43%, p = 0.01) and higher rates of critical limb-threatening ischemia (56% vs. 23%, p < 0.01) and severe calcification lesions (Peripheral Arterial Calcium Scoring Systems score 3/4) (53% vs. 34%, p = 0.01) than the non-V.S.O.P. group. The occurrence of the slow-flow phenomenon was significantly lower in the V.S.O.P. group than in the non-V.S.O.P. group. The V.S.O.P. method could be an effective method for preventing the slow-flow phenomenon after DCB angioplasty for femoropopliteal lesions.

Polymer-coated paclitaxel-eluting stents for the treatment of stenosed native arteriovenous fistulas: Long-term results from the ELUDIA study

BACKGROUND

Percutaneous transluminal angioplasty is the preferred treatment of stenosed failing arteriovenous fistulas (AVF) but is hampered by increasing rates of vascular restenosis because of development of myointimal hyperplasia.

METHODS

This multicenter observational study of polymer-coated low-dose paclitaxel-eluting stents (ELUvia stents by Boston Scientific) in stenosed AVF undergoing hemoDIAlysis (ELUDIA) was jointly conducted in three tertiary hospitals from Greece and Singapore. Failure of AVF was defined according to K-DOQI criteria and significant fistula stenosis (>50%DS by visual estimate) was determined with subtraction angiography. Patients were considered for ELUVIA stent insertion based on significant elastic recoil following balloon angioplasty for the treatment of a single vascular stenosis within a native AVF. The primary outcome measure was sustained long-term patency of the treated lesion/fistula circuit defined as successful stent placement with resumption of uninterrupted hemodialysis and without significant vascular restenosis (50%DS threshold) or other secondary interventions during follow-up.

RESULTS

Some 23 patients received the ELUVIA paclitaxel-eluting stent (eight radiocephalic, 12 brachiocephalic, and three transposed brachiobasilic native AVFs). Mean AVF age at the time of failure was 33.9 ± 20.4 months. Treated lesions included 12 stenoses at the juxta-anastomotic segment, nine at the outflow veins, and two cephalic arch lesions with a mean diameter stenosis of 86 ± 8%. Median stent diameter and length used were 7 mm and 40 mm, respectively. After a median follow-up period of 20 months, some 18 stents out of 23 cases remained patent (cumulative rate 78.3%) without any clinical or imaging evidence of recurrent stenosis. Estimated primary patency of the ELUVIA stents was 80.6% and of the corresponding fistula circuit 65.1% at 2 years by Kaplan-Meier methods.

CONCLUSIONS

This observational study has shown promising long-term results of polymer-coated paclitaxel-eluting stents for the treatment of failing arteriovenous fistulas. Large-scale controlled studies are necessary.

Efficacy and Safety of Dual Paclitaxel and Sirolimus Nanoparticle-Coated Balloon

We evaluated a novel dual active pharmaceutical ingredient (API) drug-coated balloon (DCB), which consists of a coating of nanoparticles encapsulating low-dose paclitaxel (PTX) in combination with sirolimus in a synergistic ratio. Compared to the PTX DCB, the dual API DCB demonstrated similar inhibition of cell proliferation in vitro but at a significantly lower total drug dose (over 13 times lower than sirolimus nanoparticles). Animal experiments demonstrated that the dual API DCB is more effective in inhibiting intimal cell proliferation with insignificant downstream embolic effects and myocardial damage compared to the PTX DCB. These findings indicate that dual API DCBs have a high potential to demonstrate improved clinical outcomes and a greater safety profile than the PTX DCBs.

Biological differences of three paclitaxel- and sirolimus-coated balloons on coronary lesions in a rabbit model

BACKGROUND

Drug-coated balloons (DCBs) are important treatment options for coronary artery disease; however, randomised controlled trials comparing various DCB technologies are sparse, and further investigations are needed.

AIMS

This preclinical study aimed to histologically and biologically compare the drug effects and safety of a low-dose paclitaxel-coated DCB (PCB; AGENT), a regular-dose PCB (SeQuent Please NEO) and a sirolimus-coated DCB (SCB; MagicTouch).

METHODS

The DCBs were inflated in the healthy iliac arteries of 18 rabbits, which were euthanised after 28 days. The treated iliac arteries and distal skeletal muscles were histopathologically evaluated, and drug concentrations were measured.

RESULTS

In the histopathological evaluation, the medial smooth muscle cell loss score regarding depth, an indicator of drug efficacy, was significantly higher with AGENT and SeQuent Please NEO than with MagicTouch (4.0 [3.6-4.0] vs 3.7 [3.7-4.0] vs 2.2 [2.0-2.4]), with significant differences in comparisons between AGENT and MagicTouch (p<0.01) and between SeQuent Please NEO and MagicTouch (p<0.01). AGENT and SeQuent Please NEO showed comparable drug concentrations in the treated artery (p=0.61). In contrast, the drug concentrations in distal skeletal muscles were the highest for MagicTouch, followed by SeQuent Please NEO and AGENT (28.07 [13.19-52.46] ng/mg vs 0.66 [0.22-3.76] ng/mg vs 0.25 [0.04-3.23] ng/mg, respectively).

CONCLUSIONS

This study demonstrated that PCBs might have higher efficacy and lower drug concentrations in distal skeletal muscles than the MagicTouch SCB. The efficacy of the AGENT low-dose PCB and the SeQuent Please NEO regular-dose PCB was comparable.

Comparative Evaluation of Two Paclitaxel-Coated Stents in an Experimental Setting

INTRODUCTION

Unlike paclitaxel-coated balloons, pre-clinical data comparing different paclitaxel-coated stents (PCSs) are weak. The study objective was to compare the features of the 2 main PCSs: Eluvia® (Boston Scientific, Marlborough, MA) versus ZilverPTX® (Cook Medical, Bloomington, IN).

METHOD

Analysis was carried out on 12 pigs divided into 2 groups: Eluvia® (n=6) and ZilverPTX® (n=6). The pigs received the PCS corresponding to their group in each external iliac artery and were paired one by one, to examine 6 different post-implantation timepoints: after 30 minutes, 6 hours, 24 hours, 3 days, 7 days, and 14 days. The paclitaxel concentration measurements and the histological analysis were carried out under blind testing on the plasma, arterial, lymph node, and muscle samples. A linear regression model and Wilcoxon Mann-Whitney test were used to study the variables.

RESULTS

The plasma paclitaxel rate decrease over 24 hours after PCS implantation was significantly different between the two groups, expressed by the correlation coefficient 0.19 (0.14-0.23; p<0.001) with an undetectable concentration at the 10th hour for Eluvia® versus 3 days for ZilverPTX®. Significantly higher paclitaxel concentrations with ZilverPTX® PCS were observed in muscle samples at each timepoint: extensor digitorum brevis 3.2 (1.17-5.23; p=0.005), biceps femoris 4.27 (2.27-6.26; p<0.001), semi-tendinosus 3.79 (1.85-5.73; p=0.001), tibialis anterior 3.0 (1.37-4.64; p=0.001), and in the femoral nodes 2.27±1.74 ng/g versus 0.14±0.13 ng/g (p<0.001). Histological analysis revealed a trend for more marked intimal inflammation in the arteries stented with ZilverPTX® (p=0.063), especially after the 7th and 14th days.

CONCLUSION

Such a difference in the concentration of paclitaxel in the plasma, muscles, and lymph nodes between the two stents was higher than expected based on differences in device design. The clinical consequences of these results remain to be elucidated, particularly regarding the concerning presence of paclitaxel in muscles and adjacent lymph nodes.

CLINICAL IMPACT

This experimental study compares 2 paclitaxel-coated stents. It demonstrates that differences in stent designs and drug features (coatings and concentrations) translate into differences in terms of concentrations of paclitaxel in the plasma, muscles, and lymph nodes. Our results favor the Eluvia® stent over the ZilverPTX® stent, although more studies are required to confirm this conclusion.

A systematic review and meta-analysis of sirolimus-eluting stents for treatment of below-the-knee arterial disease

OBJECTIVE

We performed a systematic review and meta-analysis to analyze the efficacy and safety of sirolimus-eluting stents (SESs) in the treatment of below-the-knee (BTK) arterial disease.

METHODS

An electronic literature search was conducted from inception to July 24, 2021. Retrospective, prospective, and randomized studies that had used SESs to treat BTK arterial disease and had reported the primary patency, technical success, target lesion revascularization, and/or mortality were included. Meta-analyses of the proportions were conducted to derive pooled summary statistics of the outcomes. Where Kaplan-Meier curves were provided for primary patency, a meta-analysis of the individual patient data was conducted via a graphic reconstruction tool to estimate primary patency at various follow-up points. For studies comparing SESs and bare metal stents (BMSs), a two-stage meta-analysis was performed to compare the 6-month primary patency of SESs vs BMSs.

RESULTS

Ten studies across 13 publications, including 995 patients, were retrieved for analysis. In the meta-analysis of proportions, across six studies (n = 339 patients), the pooled 6-month primary patency was 87.3% (95% confidence interval [CI], 81.6%-92.1%). Across seven studies (n = 283 patients), the pooled 6-month mortality was 5.4% (95% CI, 1.4%-11.2%). An individual patient data analysis of three studies (n = 282 patients) yielded a primary patency rate of 95.2% (95% CI, 92.7%-97.8%), 82.8% (95% CI, 78.3%-87.6%), 79.8% (95% CI, 75.0%-85.0%), and 79.8% (95% CI, 75.0%-85.0%) at 6, 12, 18, and 24 months, respectively. The 12-month target lesion revascularization rate across four studies (n = 324 patients) was 9.6% (95% CI, 6.4%-13.4%). In the two-stage meta-analysis of 6-month primary patency across three studies (n = 168 patients), the use of SESs was significantly favored over BMSs (risk ratio, 1.28; 95% CI, 1.12-1.46; P < .001).

CONCLUSIONS

The overall evidence suggests that the use of SESs appears to be safe and offers favorable outcomes for BTK arterial disease compared with BMSs.

Histological evaluation of vascular changes after excimer laser angioplasty for neointimal formation after bare-metal stent implantation in rabbit iliac arteries

BACKGROUND

Excimer laser is used to treat coronary artery disease, especially in case of lesions with thrombus and in-stent restenosis (ISR). However, there are no in vivo preclinical studies that have evaluated the pathological reactions of the vessel wall after excimer laser ablation.

METHODS

Bare-metal stents were placed in the external iliac arteries of six healthy rabbits. Twenty-eight days later, excimer laser ablation was performed with low-power (45 (fluency)/25 (rate)) in one side, and high-power (60/40) in the opposite side, followed by optical coherence tomography (OCT) evaluation. Rabbits were sacrificed 15 min after the procedure, and histological assessment was performed.

RESULTS

Morphometry analysis of OCT showed similar stent and lumen size between low-power and high-power group. Histological evaluation suggested endothelial cell loss, fibrin deposition, and tissue loss. The low-power group showed significantly less pathological changes compared with the high-power group: angle of endothelial cell loss, 32.4° vs. 191.7° (interquartile range, 8.8°-131.7° vs. 125.7°-279.5°; p < 0.01); fibrin deposition, 1.1° vs. 59.6° (0.0°-70.4° vs. 31.4°-178.4°; p = 0.03); and tissue loss 0.0° vs. 18.2° (0.0°-8.7° vs. 0.0°-42.7°; p = 0.03).

CONCLUSIONS

The pathological changes in neointima were more prominent after high-power excimer laser ablation than after low-power excimer laser. To improve safety in clinical practice, understanding the pathological changes of tissues after excimer laser in lesions with ISR is essential.

Slow-flow phenomenon after drug-coated balloon angioplasty for lower-extremity arteries is associated with lack of prescribing of calcium channel blockers

This study aimed to investigate the relationship between prescription drugs and the slow-flow phenomenon after drug-coated balloon angioplasty. Of 30 patients, five (17%) presented with the slow-flow phenomenon. Patients with the slow-flow phenomenon were significantly less commonly prescribed calcium channel blockers than those without the slow-flow phenomenon (P = 0.03). There was no intergroup difference in the prescription of angiotensin II receptor blockers and β-blockers. The clinical outcomes, including restenosis, thrombosis, target lesion revascularization, and death, did not differ between groups during the 10-month observation period.

Utility of sirolimus coated balloons in the peripheral vasculature - a review of the current literature

Sirolimus-coated balloons (SCB) have demonstrated much promise as an alternative drug eluting device to the existing paclitaxel coated balloon platforms for the treatment of peripheral arterial disease (PAD). They have been well tested pre-clinically and have demonstrated anti-restenotic effects as well as clinical safety in its use for treatment of coronary artery disease. The existing approved SCBs have thus far demonstrated good short-term patency (12-months) and did not exhibit any major adverse events or device related shortcomings in its use for treatment of PAD. There are several studies ongoing which aim to further investigate the efficacy of existing SCBs and establish a direct comparison of its outcomes compared with plain balloon angioplasty. Also, SCB utility to salvage failing arteriovenous fistulas for haemodialysis patients has also been explored. We review the current progress made in the establishment of SCB in the treatment of PAD as well as highlight ongoing studies investigating the role of SCB in various settings.

Slow-flow phenomena following lower limb paclitaxel- and sirolimus-coated balloon angioplasty in the setting of chronic limb threatening ischaemia-a case series

The Achilles heel of plain old balloon angioplasty (POBA) is neointimal hyperplasia (NIH) and restenosis, caused from the barotrauma of ballooning. Drug-coated balloons using a paclitaxel-based platform (PCB) have been shown to retard the restenotic process, using the anti-proliferative effects of paclitaxel, and give longer vessel patency. This is important in the setting of chronic limb threatening ischemia (CLTI) and for the protracted wound healing process in these frail patients. However, during PCB application, more than 50% of the drug is lost downstream, a phenomenon termed particulate embolization. This is thought to account for the slow- or no-flow phenomenon encountered after PCB use. Recent data suggest that slow-flow phenomenon was associated with a lower target lesion revascularisation rate and worse amputation free survival (AFS). The use of sirolimus coated balloons (SCB) to impede the NIH cascade has been less well studied but recent data suggested excellent short-term efficacy and found no slow flow phenomenon with their use in the tibial arteries in CLTI patients. Aim of this case series is to highlight the difference in flow phenomena using PCB and SCB elution in the setting of CLTI. We evaluated the use of parametric colour coding and time attenuation curves (TAC) as a quantitative measure of blood flow. SCB may have an advantage over PCB use in the peripheral vasculature because of a reduced incidence of slow flow phenomenon following drug elution.

Clinical outcome of the patients with femoropopliteal artery disease after endovascular therapy: focused on drug-coated-balloon-related distal embolism detected by laser doppler flowmetry

Several trials have shown that paclitaxel drug-coated balloons (DCBs) significantly reduce restenosis rates. However, some reports have shown distal embolisms occurring after DCBs. No study has analyzed the clinical outcomes of patients with DCB-induced distal embolism. This study aimed to investigate the clinical outcomes of DCB-induced distal embolism in patients with femoropopliteal artery disease. Between February 2018 and April 2019, consecutive patients (n = 32) who presented with de novo femoropopliteal artery disease and underwent endovascular therapy using DCB were retrospectively reviewed in a single-center study. Patients were divided into two groups based on whether distal embolism was detected using laser doppler flowmetry (DEL group) or not (non-DEL group). Baseline characteristics and 1-year clinical outcomes were compared between the groups. DEL was found in 44% of limbs (DEL group: n = 15, non-DEL group: n = 19). Below-the-knee arterial runoff ≤ 1 (p = 0.033), popliteal lesion (p = 0.044), ambulation difficulty (p = 0.021), and previous history of coronary artery disease (p = 0.013) were identified as predictive factors of DEL. Procedural factors, reference vessel diameter, lesion length, and total drug amount were not predictive of DEL. The overall target lesion restenosis (TLR) rate was 17.4% (n = 5). The TLR rate was not significantly different between the DEL and non-DEL groups (13.3% vs. 15.8%, p = 0.55). Severe calcification was the only significant factor for TLR (4.2% vs. 40.0%, p = 0.02). Among patients with femoropopliteal disease, there was no difference in 1-year clinical outcome between patients who underwent DEL and those who did not.

Mortality is not associated with paclitaxel-coated devices usage in peripheral arterial disease of lower extremities

A recent meta-analysis addressed increased risk of death following revascularization with paclitaxel-coated devices in femopopliteal artery. We evaluated differences in all-cause mortality and amputation free survival between peripheral arterial disease (PAD) patients who were treated with paclitaxel-coated devices and non-paclitaxel-coated devices. This was retrospective population-based cohort study from the National Health Insurance Service claims in South Korea from 2015 to 2019. Multivariate Cox regression analyses after propensity score matching were applied to identify all-cause mortality and amputation-free survival. After propensity score matching, there were 6090 patients per group. The median follow-up days was 580 days (interquartile range [IQR] 240–991 days) and 433 days (IQR 175–757 days) for the non-paclitaxel-coated device group and paclitaxel-coated device group, respectively. Multivariate analysis adjusted for age, sex, diabetes, hypertension, warfarin, and new oral anticoagulants showed that the mortality rate associated with paclitaxel-coated devices was not significantly higher than non-paclitaxel-coated devices (hazard ratio [HR] 0.992; 95% CI 0.91–1.08). The rate of amputation events was higher in patients with paclitaxel-coated devices than those with non-paclitaxel-coated devices (HR 1.614; 95% CI 1.46–1.78). In this analysis, the mortality rate in patients with PAD was not associated with the use of paclitaxel-coated devices, despite a higher amputation rate.

The Rollercoaster of Paclitaxel in the Lower Limbs and Skeletons in the Closet: An Opinion Review

There have been concerns about the long-term risk of all-cause death with the use of paclitaxel-coated devices in the lower limbs. Results from a 2018 meta-analysis were corroborated by the US Food and Drug Administration and later confirmed by an individual patient data meta-analysis. However, population-based observational studies have produced contradictory results and often claimed a survival benefit with the use of paclitaxel. The recently published Swedish drug-elution trial in peripheral arterial disease did not confirm a significant mortality risk. In this review, the authors discuss the key elements of the identified mortality signal and stress important facts and figures that remain underrecognized and elusive. They also highlight the important types of epidemiological bias that pertain to the ongoing debate on paclitaxel.

Frequency, predictors, and effect of the slow-flow phenomenon after drug-coated balloon angioplasty for femoropopliteal lesions

Drug-coated balloon (DCB) angioplasty for femoropopliteal (FP) lesions has been available in Japan since 2018. In daily practice, we encountered cases of the slow-flow phenomenon after DCB angioplasty. However, no data regarding the slow-flow phenomenon after DCB angioplasty for FP lesions are available. This study aimed to investigate the frequency, predictors, and effect of the slow-flow phenomenon following DCB angioplasty for FP lesions. This single-center, retrospective, observational study analyzed 88 FP lesions treated by DCB angioplasty between April 2018 and July 2019. Patients were divided into the slow-flow group (n = 7) and non-slow-flow group (n = 81) and were analyzed. The primary endpoint was primary patency at 6 months. The slow-flow phenomenon was observed in seven cases (8.0%). The slow-flow group had higher incidence rates of critical limb ischemia (CLI) (71% vs. 25%, p < 0.01), chronic total occlusion (CTO) lesions (86% vs. 26%, p < 0.01), and poor tibial vessel runoff (86% vs. 33%, p < 0.01) and had a longer DCB length (237 ± 56 mm vs. 159 ± 97 mm, p = 0.03) than the non-slow-flow group. The primary patency rate at 6 months was 71% in the slow-flow group and 91% in the non-slow-flow group (p = 0.09). The rate of freedom from target lesion revascularization at 6 months was 71% in the slow-flow group and 97% in the non-slow-flow group (p < 0.01). The amputation-free survival rate at 6 months was 71% and 95% (p = 0.02), whereas the survival rate at 6 months was 71% and 95% (p = 0.02). The incidence rate of the slow-flow phenomenon after DCB angioplasty for FP lesions was 8.0%. CLI, a CTO lesion, poor tibial vessel runoff, and total DCB length were associated with the slow-flow phenomenon. Our results indicate that the slow-flow phenomenon is associated with poor short-term clinical outcomes.

Paclitaxel-related balloons and stents for the treatment of peripheral artery disease: Insights from the Food and Drug Administration 2019 Circulatory System Devices Panel Meeting on late mortality

Following the December 2018 publication of a meta-analysis by Katsanos et al reporting higher rates of long-term mortality with the utilization of paclitaxel-related devices (balloons and stents) when compared to control in femoropopliteal arteries, the US Food and Drug Administration (FDA) issued a safety alert in January 2019 and further detailed the implications for future clinical use of these devices in March 2019. The FDA convened a public meeting of the Circulatory System Devices Panel of the Medical Devices Advisory Committee in June 2019. This report summarizes the proceedings of this meeting and the panel's response to the 12 questions posed by the FDA related to the potentially increased late mortality of drug-coated balloons and drug-eluting stents with paclitaxel in patients with peripheral arterial disease.

A universal drug delivery catheter for the treatment of infrapopliteal arterial disease using liquid therapy

OBJECTIVE

The objective of this study was to investigate the safety and feasibility of treating infrapopliteal lesions using a novel drug delivery catheter locally delivering liquid paclitaxel.

BACKGROUND

Balloon angioplasty is currently the Gold Standard to treat below-the-knee disease; however, restenosis continues to be a great challenge following these percutaneous revascularization procedures.

METHODS

The Occlusion Perfusion Catheter for Optimal Delivery of Paclitaxel for the Prevention of Endovascular Restenosis (COPPER-A) study-Below-the-Knee Cohort was a prospective, nonrandomized, multicenter, feasibility, and safety study that enrolled 35 patients at 11 participating sites. The safety endpoints at 1, 3, and 6 months were freedom from thrombosis, major amputation in the target limb and target limb related death. The efficacy endpoints were primary patency and freedom from clinically driven target lesion revascularization at 6 months.

RESULTS

All patients tolerated the procedure well with no reports of adverse procedural events. Thirty-five patients were treated with a mean lesion length of 112 ± 81.2 mm with the lesion length range of 20-286 mm. At 6-month follow-up, primary patency was 89.3% and freedom from clinically driven target lesion revascularization was 96.4%. No patients demonstrated thrombosis, major amputation in the target limb and target limb related death at the 1-, 3- and 6-months follow-up intervals.

CONCLUSIONS

The results of this multi-center study demonstrated that infrapopliteal arteries can be safely and effectively treated with liquid paclitaxel using the occlusion perfusion catheter.

Early Onset of Acute Lower Limb Drug-eluting Stent Infection

The present case describes acute and early infection of a superficial femoral artery drug-eluting stent (DES) in a 65-year-old patient 2 days after its implantation in outpatient clinic, with intense clinical presentation. The initial indication was Rutherford 3 peripheral artery disease. Radical treatment by means of stent explantation and femoro-femoral bypass using autogenous vein was performed. Both stent and blood cultures were positive for methicillin-sensitive Staphylococcus aureus. Informative imaging and intraoperative view are provided. Local evolution was satisfactory but endocarditis occurred secondarily. The pathophysiology of this first reported DES infection and the management of the infected vessel are discussed, in light of data derived from coronary literature and open vascular surgery.

IN.PACT™ Admiral™ drug-coated balloons in peripheral artery disease: current perspectives

Endovascular therapy has evolved as a main treatment option especially in patients with short (<25 cm) femoropopliteal lesion. The latest guideline recommends the use of drug-eluting devices (both drug-coated balloons [DCBs] and drug-eluting stents) in short femoro-popliteal lesions as class IIb recommendation. DCB usage is also recommended for in-stent restenosis lesions (class IIb). DCBs are a more attractive treatment option because the lack of metal prosthesis allows for more flexibility in future treatment options including the option of treating nonstenting zones, previously DCB-treated zones with DCBs again. The IN.PACT™ Admiral™ DCB has shown promising clinical performance in several randomized control trials and global registries, and is currently the market DCB leader for the treatment of femoropopliteal lesions with more than 200,000 patients treated thus far. Currently, more than 10 DCBs have received Conformité Européene mark for the treatment of femoropopliteal atherosclerotic disease. Three of these (including IN.PACT Admiral DCBs) have also received Food and Drug Administration approval in the USA. However, some Conformité Européene-marked DCBs have failed to show consistent results in their clinical studies suggesting all DCBs are not created equal. Each DCB is unique (ie, drug type, drug dose, crystallinity, and excipient) with different clinical outcomes. In the current review, we will focus on the preclinical and clinical results of not only IN.PACT Admiral DCB, but also the other currently available DCBs.

Comparison of Biologic Effect and Particulate Embolization after Femoral Artery Treatment with Three Drug-Coated Balloons in Healthy Swine Model

PURPOSE

To investigate morphometric characteristics and differences in particulate embolization between 3 drug-coated balloons (DCBs).

MATERIALS AND METHODS

Effects of 3 overlapping DCBs (IN.PACT, Ranger, and Stellarex) were assessed in 24 femoral arteries of 12 swine with 28-day follow-up. Histologic analysis of treated arterial wall site and downstream skeletal muscle and coronary band changes were assessed for evidence of emboli. Paclitaxel concentration for downstream skeletal muscle and coronary band and vessel diameters with downstream changes were also measured.

RESULTS

Signs of drug effect, such as medial smooth muscle cell (SMC) loss in depth and circumference, were not significantly different for all 3 DCBs (IN.PACT vs Ranger vs Stellarex: SMC loss depth, 2.8 [interquartile range [IQR]: 2.1-3.6] vs 3.2 [IQR: 2.3-3.8] vs 3.5 [IQR: 2.6-3.8], P = .7; SMC loss circumference, 1.0 [IQR: 1.0-1.0] vs 1.3 [IQR: 1.0-1.8] vs 1.0 [IQR: 1.0-1.2], P = .08). Percentage of sections with vascular changes in downstream nontarget tissues from arteries was similar in all 3 DCBs (42.9% vs 25.0% vs 28.6%, P = .2). Downstream levels of paclitaxel concentration in skeletal muscle were significantly higher for IN.PACT (216.5 ng/g vs 91.5 ng/g vs 101.9 ng/g, P = .01). Median vessel diameters with evidence of downstream changes were smallest for IN.PACT compared with Ranger and Stellarex (57 μm vs 74 μm vs 64 μm).

CONCLUSIONS

All 3 DCBs exhibited no significant difference in local target site drug effect based on histologic analysis. Downstream effects of paclitaxel and/or downstream emboli were highest for IN.PACT compared with Ranger and Stellarex, whereas vessel diameters with evidence of downstream changes were smaller for IN.PACT vs Ranger and Stellarex.