Retrospective analysis on diameters of drug-coated balloons and predilatation balloons in infra-inguinal endovascular treatment (RABBIT study)

This multicenter retrospective study assessed the clinical outcomes of endovascular therapy (EVT) using a drug-coated balloon (DCB) that was larger than the predilatation balloons for femoropopliteal artery lesions. We analyzed 1140 cases with symptomatic peripheral artery disease that underwent EVT with DCB for femoropopliteal lesions between 2017 and 2021. The primary endpoint was procedural failure, defined as a composite of deteriorated dissection and bailout stenting. The secondary endpoints included deteriorated dissection, bailout stenting, restenosis, and target lesion revascularization. We performed propensity score matching to compare the clinical outcomes between EVT with a DCB which was larger than the predilatation balloon (larger DCB) and EVT with a DCB which was not (nonlarger DCB). We assigned 276 cases to the larger DCB group and 864 cases to the nonlarger DCB group. Procedural failure was observed in 75 cases, whereas restenosis occurred in 282 cases during a mean follow-up period of 12.7 ± 9.7 months. Propensity score matching extracted 273 pairs with no intergroup difference in baseline characteristics, except the predilatation balloon size. Procedural failure (9.2% versus 6.1%, P = 0.11), deteriorated dissection and bailout stenting proportion (both P > 0.05), and 1-year rates of freedom from restenosis (82.4% versus 84.1%, P = 0.59) and target lesion revascularization (89.7% versus 90.4%, P = 0.83) showed no significant difference between the larger and nonlarger DCB groups. Irrespective of whether the DCB size was larger than the predilatation balloon, no difference was observed in either procedural or clinical outcomes.

Validation of the Usefulness of the Diameter Reduction, Spiral Shape, Flow Impairment, or Adverse Morphology Classification System in Real-World Clinical Practice

AIM

The accuracy of the DISFORM (diameter reduction, spiral shape, flow impairment, or adverse morphology) classification system has not been validated.

METHODS

This retrospective multicenter observational study enrolled 288 consecutive patients with lower extremity artery disease who underwent endovascular therapy with drug-coated balloons for femoropopliteal lesions between January 2018 and December 2021. Patients were classified into DISFORM I-IV groups. Primary patency (PP) and freedom from clinically driven target lesion revascularization (CD-TLR) at 12 months, and recurrence predictors at 12 months were investigated.

RESULTS

In total, 183, 66, 11, and 28 patients were classified into DISFORM I, II, III, and IV groups, respectively. In the DISFORM I, II, III, and IV groups, the PP rates were 75.3%, 91.1%, 87.5%, and 50.0%, respectively, and freedom from CD-TLR rates were 86.0%, 91.6%, 88.9%, and 76.7%, respectively, at 12 months. In the DISFORM I-III and IV groups, the PP rates were 79.4% and 50.0%, respectively, and freedom from CD-TLR rates were 87.5% and 76.7%, respectively, at 12 months. Multivariate analysis showed that chronic limb-threatening ischemia, DISFORM IV, and Lutonix™ use were independent predictors of PP loss at 12 months.

CONCLUSION

DISFORM IV had a lower PP rate than DISFORM I-III in midterm phase.

Impact of a Less Than 50% Residual Stenosis Following Vessel Preparation in Femoropopliteal Drug-Coated Balloon Angioplasty

PURPOSE

Drug-coated balloon (DCB) has been established as first-line therapy in femoropopliteal (FP) intervention, and successful vessel preparation (VP) is considered a key element. However, the clinical impact of successful VP remains unknown. This retrospective study examined the clinical impact of successful VP in DCB FP intervention.

METHODS

In total, 268 patients (308 limbs) who underwent successful FP intervention using DCB without atherectomy devices for symptomatic lower extremity artery disease between March 2018 and December 2019 were included in this study (high-dose DCB: 69.8%; low-dose DCB: 30.2%). Successful VP was defined as <50% residual stenosis and

RESULTS

The median follow-up period was 2.1 (interquartile range=1.1-2.7) years. Successful VP was achieved in 163 patients (60.8%). Primary patency and freedom from clinically-driven target lesion revascularization (CD-TLR) were significantly higher in the successful VP group than in the nonsuccessful VP group (54.2% vs 33.0%, p<0.001; 69.9% vs 57.7%, p=0.047). In the successful VP group, high-dose DCB and low-dose DCB were comparable in primary patency and freedom from CD-TLR (53.2% vs 53.6%, p=0.48; 68.7% vs 70.9%, p=0.69). In nonsuccessful VP group, high-dose DCB demonstrated numerically higher primary patency but not statistically significant than low-dose DCB (44.5% vs 16.0%, p=0.06), whereas no significant difference in freedom from CD-TLR was observed (56.0% vs 58.9%, p=0.29). On multivariate analysis, successful VP and preballoon size to reference vessel diameter ratio were significantly associated with primary patency.

CONCLUSIONS

Achieving successful VP before DCB was independently associated with primary patency in DCB FP intervention.

CLINICAL IMPACT

This study revealed that the successful vessel preparation (VP) before DCB and preballoonsize to reference vessel diameter ratio were independently associated with primary patency in DCB femoropopliteal intervention. When successful VP was achieved only before DCB treatment, the clinical outcomes were comparable between high-dose DCB and low-dose DCB at midterm follow-up.To maximized DCB efficacy, successful VP is very important in daily clinical practice.

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Key Words

• drug-coated balloon
• peripheral artery disease
• vessel preparation

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Affiliation(s)

Yusuke Tomoi Department of Cardiology, Kokura Memorial Hospital, Kitakyushu, Japan
Yoshimitsu Soga Department of Cardiology, Kokura Memorial Hospital, Kitakyushu, Japan
Kazuaki Imada Department of Cardiology, Kokura Memorial Hospital, Kitakyushu, Japan
Nobuaki Sakai Department of Cardiology, Kokura Memorial Hospital, Kitakyushu, Japan
Tomonori Katsuki Department of Cardiology, Kokura Memorial Hospital, Kitakyushu, Japan
Kenji Ando Department of Cardiology, Kokura Memorial Hospital, Kitakyushu, Japan

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Two-year clinical outcomes of drug-coated balloon angioplasty and angiographic predictors of restenosis among patients with de novo femoropopliteal lesions

OBJECTIVES

We analyzed the 2-year clinical outcomes of patients with de novo femoropopliteal (FP) lesions who underwent drug-coated balloon (DCB) angioplasty and the angiographic predictors of restenosis.

METHODS

This single-center, retrospective, and observational study evaluated 129 de novo FP lesions treated with DCB angioplasty without bailout stenting. Clinical outcomes and risk factors for loss of primary patency were analyzed using univariate and multivariate Cox proportional hazards regression models.

RESULTS

The participants were aged 48-93 (mean: 73.6 ± 9.8) years, and 31% were women. Approximately 33% of the patients were receiving regular dialysis, and 35% of the affected limbs had critical ischemia. The mean lesion length was 132 ± 96 mm, and the mean reference vessel diameter (RVD) was 4.7 ± 0.8 mm. Forty-three (33%) limbs had chronic total occlusion of the target artery segment. Fifty-seven (44%) and 72 (56%) lesions were treated with DCB angioplasty using IN.PACT Admiral and Lutonix, respectively. The primary patency and amputation-free survival at 2 years were 59.3% and 89.5%, respectively. RVD was found to be an independent predictor of loss of primary patency. Based on the receiver operating characteristic analysis, an RVD of 4.2 mm was the best predictor of loss of primary patency at 2 years.

CONCLUSIONS

The short-term clinical outcome of DCB angioplasty for de novo FP lesions was acceptable. Moreover, an RVD of <4.2 mm was an independent predictor of restenosis after DCB angioplasty.

Intravascular Ultrasound-Guided Versus Angiography-Guided Endovascular Therapy for Femoropopliteal Artery Disease: A Scoping Review

OBJECTIVE

The objective of this study was to summarize whether the application of additional intravascular ultrasound (IVUS) can change the outcomes of endovascular treatment in femoropopliteal atherosclerotic lesions compared with conventional angiography alone based on the existing study and evidence.

METHODS

Studies published until September 2022 were searched from PubMed, Embase, and Cochrane databases using the methods of combination of Medical Subject Headings and free text words. The outcomes included in these studies were primary patency rate or restenosis rate and freedom from clinically driven target lesion revascularization (cdTLR) rate, and most studies were concerned about the 12-month results. Two independent authors conducted the process of study selection. And the pooled analysis was attempted.

RESULTS

Finally, the inclusion criteria were met by 4 studies (1 randomized controlled trial and 3 retrospective studies) involving 1160 patients. IVUS played its role in measuring lesions and/or guiding wiring passage. Most of the included studies showed that IVUS could achieve a higher 12-month primary patency rate (from 70% to 90%) and higher 12-month freedom from cdTLR rate (from 83.9% to 94.7%) than angiography. The tentative pooled analysis also showed that IVUS significantly improved the 12-month primary patency rate (OR: 2.21, 95%CI: [1.38-3.55], p=0.001) and the 12-month freedom from cdTLR rate (OR: 1.70, 95%CI [1.04-2.78], p=0.03) compared with angiography alone.

CONCLUSIONS

Intravascular ultrasound-guided endovascular treatment of femoropopliteal artery lesions may have its own advantages such as higher primary patency rate and freedom from cdTLR rate at 12 months. As a novel technology, IVUS is expected to become another beneficial option to guide clinicians performing endovascular therapy in addition to angiography and may achieve better clinical outcomes. More prospective and high-quality studies are needed in the future to investigate the role of IVUS in the process of femoropopliteal artery lesions endovascular treatment.

CLINICAL IMPACT

This review summarized a few available studies to promote understanding of IVUS and reveal its potential. This novel technology shows the possibility of achieving better clinical outcomes than angiography in femoropopliteal artery lesions endovascular therapy such as higher 12-month primary patency rate shown in some studies. Currently, it is important to consider suitable technologies applied to individualized treatment. IVUS seems to provide clinicians additional option in clinical practice and benefit patients well in the future. And it needs us to conduct more high-quality studies to explore its roles and advantages in endovascular treatment.

Impact of plaque and luminal morphology in balloon angioplasty of the femoropopliteal artery: an intravascular ultrasound analysis

Objective

To assess the effect of plaque and luminal morphologies in balloon angioplasty of femoropopliteal lesions using intravascular ultrasound (IVUS).

Methods

This retrospective, observational study analyzed 836 cross-sectional images using IVUS, from 35 femoropopliteal arteries of patients who underwent endovascular treatment between September 2020 and February 2022. Pre- and post-balloon angioplasty images were matched per 5 mm. Post-balloon angioplasty images were grouped into successful (n = 345) and unsuccessful (n = 491) groups. Plaque and luminal morphologies (such as severity of calcification, vascular remodeling, and plaque eccentricity) were extracted before the balloon angioplasty procedure to identify the predictors of unsuccessful balloon angioplasty. Additionally, 103 images with severe dissection were analyzed using IVUS and angiography.

Results

In univariate analyses, the predictive factors for unsuccessful balloon angioplasty were vascular remodeling (p < .001), plaque burden (p < .001), lumen eccentricity (p < .001), and balloon/vessel ratio (p = .01). Predictive factors for severe dissections were the guidewire route (p < .001) and balloon/vessel ratio (p = .04). In multivariate analysis, the predictive factors for unsuccessful balloon angioplasty included lumen eccentricity (odds ratio [OR]: 3.99, 95% confidence interval [CI]: 1.28-12.68, p = .02) and plaque burden (OR: 1.03, 95% CI: 1.02-1.04; p < .001). For severe dissections, the independent risk factor was an eccentric guidewire route (OR: 2.10, 95% CI: 1.22-3.65, p = .01).

Conclusion

High plaque burden and luminal eccentricity were risk factors for failed femoropopliteal artery balloon angioplasty. Additionally, eccentric guidewire routes predicted severe dissection.

Simulation and Experimental Investigation of Balloon Folding and Inserting Performance for Angioplasty: A Comparison of Two Materials, Polyamide-12 and Pebax

BACKGROUND

A balloon dilatation catheter is a vital tool in percutaneous transluminal angioplasty. Various factors, including the material used, influence the ability of different types of balloons to navigate through lesions during delivery.

OBJECTIVE

Thus far, numerical simulation studies comparing the impacts of different materials on the trackability of balloon catheters has been limited. This project seeks to unveil the underlying patterns more effectively by utilizing a highly realistic balloon-folding simulation method to compare the trackability of balloons made from different materials.

METHODS

Two materials, nylon-12 and Pebax, were examined for their insertion forces via a bench test and a numerical simulation. The simulation built a model identical to the bench test's groove and simulated the balloon's folding process prior to insertion to better replicate the experimental conditions.

RESULTS

In the bench test, nylon-12 demonstrated the highest insertion force, peaking at 0.866 N, significantly outstripping the 0.156 N force exhibited by the Pebax balloon. In the simulation, nylon-12 experienced a higher level of stress after folding, while Pebax had demonstrated a higher effective strain and surface energy density. In terms of insertion force, nylon-12 was higher than Pebax in specific areas.

CONCLUSION

nylon-12 exerts greater pressure on the vessel wall in curved pathways when compared to Pebax. The simulated insertion forces of nylon-12 align with the experimental results. However, when using the same friction coefficient, the difference in insertion forces between the two materials is minimal. The numerical simulation method used in this study can be used for relevant research. This method can assess the performance of balloons made from diverse materials navigating curved paths and can yield more precise and detailed data feedback compared to benchtop experiments.

Propensity score-matched analysis of six-month outcomes of paclitaxel-coated balloons combined with UltraScore balloons versus conventional scoring balloons for femoropopliteal lesions

PURPOSE

Combination angioplasty with paclitaxel-coated balloons (PCBs) and conventional scoring balloons for femoropopliteal lesions has demonstrated satisfactory results, even for complex lesions. The UltraScore balloon (Becton Dickinson, New Jersey, USA), which has a maximum length of 300 mm, has two longitudinal 0.010-inch stainless steel wires and is a new treatment option for complex femoropopliteal lesions. However, no studies have evaluated the effect of the UltraScore balloon on femoropopliteal lesions. This study aimed to compare the clinical efficacy of angioplasty over a six-month period using UltraScore balloons versus conventional scoring balloons for the treatment of atherosclerotic femoropopliteal lesions with PCBs.

METHODS

A retrospective single-center observational study enrolled 272 patients who underwent PCB angioplasty combined with an UltraScore balloon (n = 58) or conventional scoring balloon (n = 214) without bailout stenting. Propensity score matching was used to minimize intergroup differences in baseline characteristics, and six-month outcomes were compared between the two groups. The primary endpoint was a technical success (i.e., residual angiographic stenosis of <30% with non-severe dissection). The secondary endpoints were the incidences of periprocedural complications, restenosis, and target lesion revascularization (TLR).

RESULTS

After propensity score matching, 50 matched pairs of patients were selected for analysis. The UltraScore group had a significantly longer vessel length (192.8 ± 94.9 versus 36.6 ± 7.9 mm, P < 0.001), a lower frequency of non-compliant balloon (26.0% versus 56.0%, P = 0.002), and a smaller PCB diameter (5.32 ± 0.65 versus 5.66 ± 0.52 mm, P = 0.002) compared with the scoring group. The primary endpoint of technical success was significantly higher in the UltraScore group than in the scoring group (76.0% versus 56.0%, P = 0.035). There were no significant differences in periprocedural complications (4.0% versus 2.0%, P = 0.562), six-month restenosis (4.0% versus 8.0%, P = 0.339), and TLR (2.0% versus 4.0%, P = 0.500) between both groups. The multivariate logistic regression analysis showed that UltraScore use was independently associated with an increase in technical success (odds ratio: 2.58; 95% confidence interval: 1.05-6.36, P = 0.040).

CONCLUSION

The use of an UltraScore balloon during PCB angioplasty for femoropopliteal lesions significantly improved technical success compared with conventional scoring balloons. UltraScore use was an independent predictor of technical success, indicating its potential advantages in peripheral intervention procedures.

Comparing the impact of the loss of patency between treatment with drug-coated balloon angioplasty and drug-eluting stent placement

OBJECTIVE

To compare the results of endovascular treatment with drug-eluting stents (DES) and drug-coated balloons (DCB) in atherosclerotic lesions in the femoropopliteal artery, as well as to assess restenotic patterns.

METHODS

Clinical data from 617 cases treated with DES or DCB for femoropopliteal diseases were analyzed in this multicenter, retrospective cohort study. From these, 290 DES and 145 DCB cases were extracted by propensity score matching. Outcomes investigated were 1- and 2-year primary patency, reintervention, and restenotic pattern and its impact on symptoms in each group.

RESULTS

The primary patency rates at 1 and 2 years in the DES group were superior to those in the DCB group (84.8% and 71.1% vs 81.3% and 66.6%, P = .043), whereas there was no significant difference in freedom from target lesion revascularization (91.6% and 82.6% vs 88.3% and 78.8%, P = .13). Compared with what was measured before the index procedures, exacerbated symptoms, rate of occlusion, and an increase in the occluded length at loss of patency were more frequent in the DES group than in the DCB group. The odds ratios were 3.53 (95% confidence interval, 1.31-9.49; P = .012), 3.61 (1.09-11.9; P = .036), and 3.82 (1.15-12.7; P = .029), respectively. On the other hand, the frequency of an increase in lesion length and requirement of target lesion revascularization were similar between the two groups.

CONCLUSIONS

Primary patency was significantly higher at 1 and 2 years in the DES than in the DCB group. However, DES were associated with exacerbated clinical symptoms and complicated lesion characteristics at the point of loss of patency.

Impact of Chocolate percutaneous transluminal angioplasty balloon on vessel preparation in drug-coated balloon angioplasty for femoropopliteal lesion

Purpose

To compare the impact of Chocolate and conventional balloons on vessel preparation in percutaneous transluminal angioplasty.

Materials and methods

This single-center retrospective study included 111 endovascular therapy consecutive cases of femoropopliteal lesions using drug-coated balloon strategy with a 1:1 pre-dilation balloon diameter between February 2020 and August 2021, divided into the Chocolate percutaneous transluminal angioplasty (n = 48) and conventional (n = 63) groups. Before the availability of Chocolate balloons in Japan (December 2020), a standard semi-compliant or non-compliant balloon was used for vessel preparation. The primary endpoint was rate of severe dissection after pre-dilatation. Secondary endpoints were angiographic percent diameter stenosis, bailout stent rate, primary patency rate, and freedom from target-lesion-revascularization rate at six months.

Results

There was no significant difference in patient and lesion characteristics. The procedural characteristics comprised balloon length 90 ± 37 and 149 ± 95 mm (P = 0.004) and inflation pressure 11 ± 3 and 16 ± 7 atm (P < 0.001) in the Chocolate and conventional groups, respectively. Regarding primary endpoint, rates of severe dissection were 4.2% and 25% (P = 0.003); regarding secondary endpoints, percent diameter stenosis was 18 ± 15% and 20 ± 17% (P = 0.409), and the rate of bailout stenting was 2.1% and 15.9% (P = 0.016) in the Chocolate and conventional groups, respectively. The primary patency rates at six months were 89.1% and 85.2% (P = 0.670), and freedom from target-lesion-revascularization rate at six months was 100% and 92.8% (P = 0.691) in the Chocolate and conventional groups, respectively.

Conclusion

Chocolate percutaneous transluminal angioplasty balloons reduce the rate of severe dissection while maintaining a sufficient dilatation effect during drug-coated balloon vessel preparation.

Retrograde Guidewire-Assisted Remodeling Technique: A Novel Technique for Endovascular Recanalization of Occluded Arterial Origins in Critical Limb Ischemia

PURPOSE

The main objective of this study is to describe the retrograde guidewire-assisted remodeling technique (REGART), a novel technique, and assess its feasibility, safety, and effectiveness in the recanalization of ostial arterial occlusions without a visible stump in the critical limb ischemia (CLI).

MATERIALS AND METHODS

A retrospective review of 387 patients who underwent endovascular treatment (EVT) for peripheral artery disease between January 2020 and June 2021 was performed. Among these, 23 patients (14 males [60.8%]) with a mean age of 64.2 (range: 55-72) years who underwent REGART were included. Patient demographics, procedural details, and outcomes were noted.

RESULTS

The technical success rate was 95.6% (22/23). The angiographic success rate was 86.3% (19/22). The procedure-related complication rate was 21.7% (5/23), with 4 (17.4%) major complications and 1 (4.3%) minor complication.

CONCLUSION

In the CLI, results of this trial suggest that REGART is feasible, effective, and with acceptable safety in the catheterization of occluded artery origins without a visible stump when conventional anterograde and retrograde techniques fail. Thus, the target occluded artery can be recanalized while preserving other arterial origins by minimizing dissection risk through subintimal balloon angioplasty at the bi-trifurcation level.

Antegrade dissection of external iliac artery after failed attempt of common femoral artery chronic total occlusion angioplasty

Introduction. Endovascular treatment of chronic total occlusion (CTO) represents a true challenge even for experienced interventional radiologists. We are presenting a case of hidden antegrade dissection of the external iliac artery (EIA) after a failed attempt to recanalize CTO of the common femoral artery (CFA). Case outline. A 52-year-old male patient was admitted for multidetector computed tomography (CT) angiography. Left common iliac artery (CIA) stenting was performed, followed by ?crossover? attempt of recanalization of right CFA CTO that failed. The next day, left femoral superficial artery angioplasty was performed and after one month, angioplasty of the left popliteal and the bellow-knee arteries. A month later, the patient was readmitted for surgical reconstruction of the CFA. After desobstruction, excellent inflow was obtained and a Dacron graft was inserted. A few hours postoperatively, Fogarty catheter thrombectomy was performed. The next morning, pulsations were weakened again and CT angiography showed antegrade dissection of the EIA. Stenting of the EIA was performed with two stents and a favorable outcome was achieved. After a detailed analysis of the CT, hidden thrombosed antegrade dissection of the EIA was noted in the lateral view, which was not seen in the posterior/anterior view and was presented as fibrous plaque with mural thrombosis. Dissection occurred after failed attempt of CFA recanalization and was clinically silent until flow was established triggering opening of the false lumen and the release of thrombotic masses. Conclusion. In patients with failed angioplasty of CTO of the CFA and CT characteristics of fibrous plaque proximal to the site of attempted angioplasty, thrombosed antegrade dissection should be considered.

Comparison of Angiographic Dissection Classification Systems in the Femoropopliteal Arteries Using IVUS Validation and Reliability Testing

PURPOSE

Objective assessment of dissection severity is difficult. Recognition of this has led to the creation of classification systems. This study investigated the performance of the National Heart Lung and Blood Institute (NHLBI) and Kobayashi systems at differentiating severity of femoropopliteal dissection using intravascular ultrasound (IVUS) as the reference standard. Comparison between the 2 systems and the inter- and intra-observer reliability were also investigated.

MATERIALS AND METHODS

Angiographic and IVUS imaging was assessed in 51 cases sourced from a RCT investigating the use of IVUS in femoropopliteal disease. A total of 2 readers independently scored the angiography images according to NHLBI and Kobayashi dissection classification systems and a consensus score was obtained for each system in each case. The NHLBI classification was condensed into 3 grades of dissection to allow comparison between systems. Dissection length, dissection arc, minimum lumen area, and lumen area stenosis were obtained from the IVUS imaging. IVUS parameters were compared between grades of severity for both systems. Agreement in grading between the systems was assessed and IVUS parameters for each level of dissection severity were compared between systems. Inter and intra-observer agreement tested for each system.

RESULTS

Dissection was present on IVUS in 92.2% (47/51) of cases and angiography identified 78.7% (37/47) of these. No difference was present in any IVUS parameters between mild and severe dissections with either classification system. No difference in IVUS findings was present for the same grades of dissection between systems. The 2 systems agreed on severity grade in 47 of 51 cases. The inter-observer agreement was for NHLBI was k=0.549 and k=0.627 for Kobayashi. Intra-observer agreement for NHLBI was k=0.633 and k=0.633 and for Kobayashi was k=0.657 and k=0.297.

CONCLUSION

The lack of difference in IVUS parameters between mild and severe dissection for the NHLBI and Kobayashi systems raises doubts about their ability to effectively differentiate dissection severity. Weak to moderate reliability suggests that variability in interpreting dissection may be higher than acceptable. IVUS imaging is more sensitive for detecting dissection than angiography and research is required to establish the value of adding IVUS to dissection classification systems.

Outcomes of Dissection Angles as Predictor of Restenosis after Drug-Coated Balloon Treatment

AIM

The predictors of restenosis after endovascular therapy (EVT) with paclitaxel drug-coated balloons (DCBs) have not been clearly established. The present study aimed to investigate the association of post-procedural dissection, as evaluated using intravascular ultrasound (IVUS), with the risk of restenosis following femoropopliteal EVT with paclitaxel DCBs.

METHODS

In the present single-center retrospective study, 60 de novo femoropopliteal lesions (44 patients) that underwent EVT with DCBs, without bail-out stenting, were enrolled. The primary outcome was 1-year primary patency. Risk factors for restenosis were evaluated using a Cox proportional hazards regression model and random survival forest analysis.

RESULTS

The 1-year primary patency rate was 57.2% [95% confidence interval, 45%-72%]. IVUS-evaluated post-procedural dissection was significantly associated with the risk of restenosis (P=0.002), with the best cutoff point of 64º [range, 39º-83º]. The random survival forest analysis showed that the variable importance measure of IVUS-evaluated dissection was significantly lower than that of the reference vessel diameter (P＜0.001), not different from that of the lesion length (P=0.41), and significantly higher than that of any other clinical feature (all P＜0.05).

CONCLUSION

IVUS-evaluated post-procedural dissection was associated with 1-year restenosis following femoropopliteal EVT with DCB.

Clinical outcome of drug-coated balloon versus scaffold device in patients with superficial femoral artery chronic total occlusion

The demand for endovascular therapy is increasing in an aging society, but the problem of restenosis in the chronic phase has not been resolved in femoropopliteal occlusive disease. Few studies have compared drug-coated balloon (DCB) and scaffold devices in chronic total occlusion (CTO) of the superficial femoral artery (SFA). This study aimed to compare DCBs with scaffold in patients with CTO of the SFA. This was a single-center, retrospective study. From June 2018 to December 2019, we compared 31 patients and 33 limbs treated with DCBs and 44 patients and 45 limbs treated with a stent or stent-graft (scaffold) for SFA CTO. The primary endpoint was 12-month primary patency. The secondary endpoints were 12-month freedom from clinically driven target lesion revascularization (CD-TLR) and 12-month freedom from re-occlusion. The DCBs were performed using an intravascular ultrasound (IVUS)-guided approach or a non-loop wire technique. Baseline characteristics were similar between the groups. An intraluminal approach was performed to use all DCBs. The bailout stent rate was 0% in the DCB group. Kaplan-Meier analysis showed that rates of 12-month primary patency tended to be higher in the DCB than in the scaffold group (92.7 vs. 76.6%, p = 0.073) and that freedom from CD-TLR also did not differ significantly between the two groups (96.8 vs. 86.3%, p = 0.17). Kaplan-Meier analysis also showed that the 12-month freedom from re-occlusion rate was significantly less in the Scaffold than in the DCB group (96.8 vs. 79.3%, p = 0.045). Therefore, we concluded that in treatment for CTO of the SFA, a DCB with intraluminal angioplasty without bailout stenting was less re-occlusion compared with scaffold.

Predictor analysis of 1-year restenosis after percutaneous transluminal angioplasty for femoropopliteal stenotic lesions using intravascular ultrasound

This retrospective, single-center study evaluated the patency rate and predictors of restenosis after percutaneous transluminal angioplasty (PTA) for femoropopliteal stenotic lesions using intravascular ultrasound. We assessed 78 de novo femoropopliteal stenotic lesions (64 patients; mean age, 73.6 ± 9.4 years; average lesion length, 59.8 mm) that underwent PTA under intravascular ultrasound guidance. The primary endpoint was 1-year primary patency. The 1-year primary patency rate was 63%. The frequency of insulin use was significantly greater (44% vs. 12%, p = 0.005), and lesions were significantly longer (77.8 mm vs. 49.2 mm, p = 0.047) in the restenosis group than in the non-restenosis group. The pre-intervention reference lumen area and minimum lumen area (MLA) were significantly smaller in the restenosis group (reference lumen area: 19.7 ± 6.7 mm² vs. 23.7 ± 7.4 mm², p = 0.017; MLA 3.9 ± 2.8 mm² vs. 5.7 ± 3.9 mm², p = 0.026; respectively). The MLA was significantly smaller and the maximum angle of dissection was significantly larger in the restenosis group (MLA 9.3 mm² vs. 12.3 mm², p = 0.013; maximum angle of dissection: 104.1° vs. 69.6°, p = 0.003; respectively) among post-intervention parameters. Multivariate analysis revealed that the independent predictors of 1-year restenosis were the large post-intervention maximum angle of dissection and insulin use. Per receiver operating curve analysis, the best cut-off value of the post-intervention maximum angle of dissection that predicted 1-year restenosis was 70.2° (sensitivity 72.4%, specificity 63.3%, area under the curve 0.70, p = 0.004). In conclusion, the 1-year primary patency rate after PTA for relatively short stenotic femoropopliteal lesions was 63%. The large post-intervention maximum angle of dissection, measured using intravascular ultrasound, and insulin use were independent predictors of restenosis after PTA.

Impact of Guidewire Route on Severe Dissection After Balloon Angioplasty for Femoropopliteal Chronic Total Occlusion Lesions: An Intravascular Ultrasound Analysis

OBJECTIVE

To determine the impact of the guidewire route on severe dissection after balloon angioplasty for femoropopliteal chronic total occlusion (CTO) lesions using a new intravascular ultrasound (IVUS) assessed classification scheme corresponding to a conventional angiographic classification scheme.

METHODS

Images for 21 femoropopliteal CTO lesions treated endovascularly between May 2018 and December 2019 were used for analysis. IVUS images after guidewire passage and those after balloon angioplasty were evaluated at 1 cm intervals. Cross sectional images were obtained (n = 219) and divided into two groups by the guidewire route: those in which the guidewire passed through the inner half of the luminal radius (central wiring group, 139 cross sectional images) and those in which the guidewire passed through the outer half of the luminal radius (eccentric wiring group, 80 cross sectional images). Angiographically severe dissection was defined as Type C or greater according to the National Heart, Lung, and Blood Institute classification, to which six dissection morphology patterns were applied based on IVUS images (Types A - E2).

RESULTS

Central wiring was achieved in an average of 69.6 ± 28.0% of the CTO length from per limb analysis. Among the IVUS assessed dissection morphology patterns, Types D - E2 were more frequently correlated with angiographically severe dissection than were Types A - C (57.5% vs. 13.7%, p < .001). Multivariable analysis showed that soft plaque was a predictive factor for (odds ratio [OR] 2.14; 95% confidence interval [CI] 1.007 - 4.72; p = .048) and central wiring was a protective factor (OR 0.27; 95% CI 0.14 - 0.49; p < .001) against Type D - E2 dissection patterns assessed by IVUS after balloon angioplasty.

CONCLUSION

Lesions with Type D - E2 dissection patterns assessed by IVUS were correlated with angiographically severe dissection. Central wiring may be useful for preventing severe dissection after balloon angioplasty for femoropopliteal CTO lesions.

Efficacy of Super Slow Inflation as Lesion Preparation for Drug-Coated Balloons in Femoropopliteal Lesions

Background: Drug-coated balloon strategies in endovascular therapy often result in severe dissection, so lesion preparation must be improved. We evaluated the efficacy of a gradual inflation method, termed "super slow inflation" (SSI), in preparing lesions to avoid severe dissections. Methods and Results: The association between balloon pressure and the dilatation of a model constricted vessel, as well as the load applied to the balloon surface, were determined using a burst leak detector for a quick inflation (QI; 1 atm/s) protocol and SSI (1 atm/20 s). A retrospective, single-center, non-randomized study evaluated differences in vessel dissection patterns after balloon angioplasty depending on inflation method in 81 consecutive patients (mean [±SD] age 74.6±9.2 years; 54 males) who underwent balloon angioplasty for de novo femoropopliteal lesions between January 2017 and March 2019. In the constricted vessel model, vessel dilatation increased gradually using SSI, with the maximum dilatation load being approximately 100 g lower for the SSI than QI protocol. In patients, the rate of severe vessel dissection was significantly lower in the SSI than non-SSI group (17.6% vs. 55.2%, respectively; P<0.001). Multivariate regression analysis revealed that SSI was an independent factor preventing severe dissection (odds ratio 0.18; 95% confidence interval 0.06-0.53; P=0.002). Conclusions: SSI is a gentle and effective method for the preparation of femoropopliteal lesions to reduce the incidence of severe angiographic dissection when using drug-coated balloons.

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.

Impact of Scoring Balloons on Percutaneous Transluminal Angioplasty Outcomes in Femoropopliteal Lesions

Purpose: To investigate the efficacy of scoring balloons for immediate success of percutaneous transluminal angioplasty (PTA) in femoropopliteal lesions. Materials and Methods: Between 2013 and 2019, 398 consecutive patients with de novo femoropopliteal lesions were treated using PTA in our hospital. The procedure success rate was compared among patients undergoing PTA with vs without scoring balloons after 1:1 propensity score matching on hemodialysis, TransAtlantic Inter-Society Consensus II classification, Peripheral Arterial Calcium Scoring System (PACSS) grade, lesion length, and use of intravascular ultrasound. Propensity matching produced 84 patients (mean age 73.4±8.3; 65 men) treated with scoring balloons and 84 patients (mean age 75.6±8.7; 56 men) treated with plain balloons. Kaplan-Meier analysis investigated patency after the procedure in both groups; estimates are given with the 95% confidence interval (CI). Results: Residual stenosis <30% was achieved more often (77.4% vs 57.1%, p=0.005) and severe arterial dissection occurred less frequently (16.7% vs 29.8%, p=0.043) in the scoring balloon group vs the plain balloon group, respectively. The rate of provisional stenting was significantly lower after scoring balloon use (13.3% vs 29.8%, p=0.008). Multivariable analysis revealed that use of scoring balloons (p<0.001) and prolonged inflation time (p<0.001) were independent predictors of successful angioplasty, whereas chronic total occlusion (p=0.005) and longer lesion length (p=0.005) were predictors of an unsuccessful procedure. Among 108 patients with PACSS 0–3 lesions in the matched population, Kaplan-Meier analysis showed better primary patency at 18 months in the scoring balloon group in the intention to treat analysis [68.6% (95% CI 53.5% to 80.6%) vs 43.0% (95% CI 28.7% to 58.5%), p=0.044]. Conclusion: Scoring balloons may be effective in restoring acute lumen gain and preventing severe arterial dissection in femoropopliteal lesions. Moreover, scoring balloons might be associated with better primary patency at 18 months in PACSS 0–3 lesions.

Usefulness of the “Non-Slip Element” Percutaneous Transluminal Angioplasty Balloon in the Treatment of Femoropopliteal Arterial Lesions

Purpose: To evaluate a new scoring balloon, the non-slip element (NSE) percutaneous transluminal angioplasty (PTA) balloon, in the treatment of femoropopliteal lesions by comparing angiographic dissection patterns to those of a conventional balloon. Methods: This retrospective, single-center study included 71 symptomatic patients (mean age 77.4±8.8 years; 33 men) with de novo femoropopliteal lesions <20 cm long treated with balloon angioplasty between January 2017 and May 2018. Thirty-four patients were treated with 3 inflations of an NSE balloon and 37 patients were treated with a conventional balloon. Results: Severe dissections were fewer (8.8% vs 29.7%, p=0.027) and the total dissection length was shorter (11.5±12.8 vs 35.7±24.1 mm, p=0.027) in the NSE group. The bailout stenting rate was also lower in the NSE group (17.6% vs 40.5%, p=0.035). There were no significant differences between the groups regarding lesion length (70.3±50.4 vs 77.8±56.6 mm, p=0.28), inflation time (294±162 vs 353±179 seconds, p=0.08), or inflation pressure (10.6±5.0 vs 11.3±5.3 atm, p=0.31). Conclusion: Three NSE balloon inflations may reduce severe dissections induced by balloon angioplasty in femoropopliteal lesions.

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.

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.

Impact of Prolonged Inflation Times During Plain Balloon Angioplasty on Angiographic Dissection in Femoropopliteal Lesions

Purpose: To investigate if balloon angioplasty with a prolonged inflation time (>3 minutes) can prevent postdilation dissection in femoropopliteal lesions. Methods: A retrospective single-center analysis examined 294 consecutive patients (mean age 74.1±8.7 years; 215 men) with de novo femoropopliteal lesions treated with balloon angioplasty between 2013 and 2018. The patients were classified into 2 groups to compare angiographic dissection patterns: 175 patients treated with balloon angioplasty for 3 minutes (3-minute group) and 119 treated for >3 minutes (>3-minute group). Results: Mean balloon inflation time was 7.8±2.7 minutes in the >3-minute group. Severe dissections (type C or higher) were observed less frequently after balloon dilation in the >3-minute group (22.7% vs 50.9%, p<0.001); therefore, significantly more patients in the >3-minute group had successful endovascular treatment after initial balloon angioplasty (57.1% vs 38.3%, p=0.001). Additional balloon dilation was attempted more frequently in the 3-minute group (30.9% vs 14.3%, p=0.001); as a result, there were more patients in whom additional balloon dilation repaired severe dissection that occurred after the initial dilation (25.1% vs 10.9%, p=0.001). Multivariate analysis revealed that chronic total occlusion (p<0.001) and longer lesion (p<0.001) were independent predictors of severe dissection, and prolonged dilation time was independently related to preventing severe dissection (p<0.001). Among 171 patients undergoing successful balloon angioplasty without stent implantation, the Kaplan-Meier estimates of primary patency within 1 year did not differ significantly according to inflation time. Conclusion: Balloon dilation with prolonged inflation time (>3 minutes) may be effective as an initial strategy to prevent severe dissection in femoropopliteal lesions compared to inflation for 3 minutes.