Differences in Intravascular Ultrasound Measurement Values Between Treatment Modalities for Restenosis in Femoropopliteal Lesions

Adjunctive Utilization of Intravascular Ultrasound in Peripheral Arterial Disease Treatment

BACKGROUND

The utility and benefit of intravascular ultrasound (IVUS) has been well established in coronary interventions, however widespread adoption for peripheral interventions has lagged. The objectives of this review article were to discuss the technical components of IVUS, describe key learning pearls for IVUS utilization, and review the literature describing the clinical outcomes of endovascular peripheral arterial interventions using IVUS.

METHODS

A scoping review of the current literature utilizing Pubmed. Terms used to search the literature included "intravascular ultrasound (IVUS)" in conjunction with "peripheral arterial disease (PAD)," "endovascular interventions," "chronic limb threatening ischemia," "balloon angioplasty" "stenting," "percutaneous coronary intervention," and "outcomes." All types of articles were reviewed including review articles, retrospective reviews, meta-analyses, and prospective observational and randomized studies.

RESULTS

Published literature regarding IVUS use in peripheral arterial interventions is heterogeneous and limited to mainly retrospective studies, registry analyses and metanalyses. Outcomes are generally favorable with the adjunct of IVUS compared to traditional angiography-driven peripheral interventions. The addition of IVUS improves stent expansion, stent patency, and reduces reintervention rates, particularly in infrainguinal arterial lesions. Long-term costs may also be lower with IVUS-guided procedures.

CONCLUSIONS

Expert consensus largely supports the implementation of IVUS in endovascular interventions for peripheral arterial disease. However, more robust high-quality data evaluating the efficacy, durability, and cost of IVUS in peripheral arterial disease are still needed.

Impact of Procedural Techniques on Midterm Patency of Fluoropolymer-Based Drug-Eluting Stent Placed in the Femoropopliteal Artery

PURPOSE

To investigate the impact of compliance with recommended procedural techniques on the midterm patency of a fluoropolymer-based drug-eluting stent (FP-DES) in the femoropopliteal artery.

MATERIALS AND METHODS

This retrospective study included 200 femoropopliteal lesions (chronic limb-threatening ischemia, 59%; chronic total occlusion, 41%) in 173 patients (male, 66%; diabetes mellitus, 62%; hemodialysis, 40%) with lower extremity arterial disease who underwent intravascular ultrasound (IVUS)-guided endovascular therapy with FP-DES between January 2016 and July 2021. The primary outcome measure was restenosis, defined as a peak systolic velocity ratio of >2.4 based on the duplex US findings. The association between procedural techniques and incidence of restenosis was investigated using Cox proportional hazards regression models.

RESULTS

The 2-year cumulative incidence of restenosis was 19.5% (SD ± 3.3). Multivariate analysis revealed that noncompliance with recommended procedural techniques, such as plaque burden at the stent edge of <50%, a minimum stent area (MSA) of >12 mm2, and stent placement within the P1 segment, was independently associated with an increased risk of restenosis (hazard ratios [HRs], 3.22, 4.71, and 4.67 and P = .004, P < .001, and P < .001, respectively). The 2-year restenosis risk for procedures performed in compliance with all 3-technical criteria was 8.4% (SD ± 3.4), whereas the risks for those in compliance with 2-technical criteria or 0- or 1-technical criteria were 25.0% (SD ± 6.2) and 48.6% (SD ± 10.4), respectively. HRs relative to 3-technical criteria compliance were 3.79 (P = .007) and 11.85 (P < .001), respectively.

CONCLUSIONS

Noncompliance with recommended procedural techniques, including plaque burden at the stent edge of <50%, MSA of >12 mm2, and stent placement within the P1 segment, was significantly associated with an increased risk of 2-year restenosis after FP-DES implantation in the femoropopliteal artery.

Comparing Predictors Influencing Restenosis Following High-Dose Drug-Coated Balloon Angioplasty and Fluoropolymer-Based Drug-Eluting Stenting in Femoropopliteal Artery Lesions

PURPOSE

Despite widespread use of anti-restenosis devices, drug-coated balloons (DCBs) and drug-eluting stents (DESs), their appropriate use for femoropopliteal (FP) lesions has not been well investigated and the risk factors for restenosis have not been compared. To investigate risk factors associated with restenosis after endovascular therapy using DCB and DES for contemporary FP lesions.

MATERIALS AND METHODS

This single-center, retrospective, observational study evaluated 378 FP lesions in 273 patients treated with DCB (278 lesions in 193 patients) or DES (120 lesions in 106 patients). The DCB used was high-dose DCB (IN.PACT, Admiral. Medtronic, Inc.) and DES was fluoropolymer-based DES (ELUVIA, Boston Scientific). Vessel preparation failure was defined as a residual stenosis of ≥50% and a dissection grade of D or greater on pre-dilatation angiography. The outcome measure was restenosis, and factors associated with restenosis in the DCB and DES groups were assessed using a Cox proportional hazards model.

RESULTS

The 2-year restenosis rate was not significantly different between the DCB and DES groups (29%±4% vs. 24%±5%, p=0.42). Interaction analysis demonstrated that popliteal lesions and plaque burden of ≥50% were restenosis-related factors for DES but not for DCB, whereas vessel preparation failure was a factor for DCB but not for DES (p<0.05). Vessel diameter of <6 mm and nodular calcification were risk factors in both groups (p<0.05).

CONCLUSION

In contemporary FP lesions, smaller vessels and nodular calcification were shared restenosis-related factors for high-dose DCB and fluoropolymer-based DES. Popliteal lesions and plaque burden of ≥50% were restenosis-related factors for fluoropolymer-based DES and vessel preparation failure for high-dose DCB.

CLINICAL IMPACT

Shared and differential restenosis-related factors after endovascular therapy using high-dose drug-coated balloons (DCBs) and fluoropolymer-based drug-eluting stents (DESs) in contemporary femoropopliteal (FP) lesions are unclear. This single-center retrospective study included 378 FP lesions in 273 patients with lower-extremity arterial disease (high-dose DCB, 278 lesions in 193 patients; fluoropolymer-based DES, 120 lesions in 106 patients). Smaller vessels and calcified nodules were shared restenosis-related factors for both high-dose DCB and fluoropolymer-based DES, whereas popliteal lesions and plaque burden of ≥50% were restenosis-related factors for fluoropolymer-based DES and vessel preparation failure for high-dose DCB.

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.

Accuracy and Reliability of Peripheral Artery Calcium Scoring Systems Using an Intravascular Ultrasound Reference Standard

BACKGROUND

Peripheral artery calcium scoring systems are commonly used in clinical trials to categorize calcium severity but there are little data on their accuracy and reliability. The purpose of this study was to investigate the accuracy and reliability of these systems.

METHODS

Angiographic, computed tomography angiography, and intravascular ultrasound (IVUS) imaging were obtained from 47 consecutive cases sourced from a prospectively collected database of patients undergoing femoropopliteal artery endovascular intervention. Two independent blinded readers graded calcium severity using the Peripheral Arterial Calcium Scoring System, Peripheral Academic Research Consortium, and Fanelli calcium scoring systems. IVUS maximum arc of calcium and calcium length were compared between severity grades for each scoring system. The diagnostic accuracy of each scoring system for identifying severe calcium was calculated using the reference standard of an IVUS maximum calcium arc ≥ 180°. Agreement testing was performed between scoring systems and between and within observers for each system.

RESULTS

IVUS identified calcium in 85% (42/47) of cases, compared to 68% (32/47) of cases with angiography. There were no differences in IVUS calcium parameters between grades of calcium for any of the scoring systems. Severe calcium was detected by IVUS in 30 cases, in 23 cases by Peripheral Arterial Calcium Scoring System (sensitivity: 73%, specificity: 33%, positive predictive value [PPV]: 83%, negative predictive value [NPV]: 22%), in 12 cases by Peripheral Academic Research Consortium (sensitivity: 42%, specificity: 83%, PPV: 92%, NPV: 25%), and in 10 cases by Fanelli (sensitivity: 39%, specificity: 100%, PPV: 100%, NPV: 27%). Agreement between scoring systems was weak to moderate (range: k = 0.55-0.74). Interobserver agreement was weak (k = 0.41-0.54) and intraobserver agreement was highly variable ranging from k = 0.41 to k = 0.92.

CONCLUSIONS

The poor diagnostic accuracy and weak-to-moderate reliability of calcium scoring systems raise doubts about the use of current calcium scoring systems for use in clinical trials.

Predictability and usefulness of intravascular ultrasound-guided angioplasty in patients with femoropopliteal lesions: a systematic review and meta-analysis

INTRODUCTION

To assess whether intravascular ultrasound (IVUS)-guided angioplasty in femoropopliteal lesions would improve clinical outcomes and predict restenosis.

EVIDENCE ACQUISITION

Studies in which IVUS-guided angioplasty was used for femoropopliteal lesions were searched from the MEDLINE, Embase, Web of Science, and Cochrane databases; articles with the full text were included. The primary endpoint of this study was primary patency at 12 months, while the secondary endpoints were primary patency at 24 months, freedom from target lesion revascularization (TLR) at 12 months, and correlation of restenosis with the distal external elastic membrane (EEM) area, post-intervention minimum lumen area, lesion length, dissection, and calcification.

EVIDENCE SYNTHESIS

Altogether, 11 observational studies involving 1521 patients (1703 lesions) were analyzed. The quality of the evidence for 7 main outcomes was assessed as "very low" by The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) classification. The mean follow-up period was 1.5 years. The pooled rates were: 78% for 12-month primary patency (95% confidence interval [CI], 0.72-0.83), 74.3% for 24-month primary patency (95% CI, 0.71-0.78), and 80% for 12-month freedom from TLR (95% CI, 0.74-0.86). The 12-month primary patency of IVUS use (relative risk [RR], 2.01; 95% CI, 1.48-2.74) was higher compared to non-IVUS use. The minimum lumen (stent) area (standard mean difference (SMD) = -0.30; 95% CI, -0.46 to -0.15) and dissection (OR 1.58; 95% CI, 1.01-2.49, P = 0.047), were associated with midterm patency in terms of restenosis.

CONCLUSIONS

In IVUS-guided angioplasty in patients with femoropopliteal lesions, the minimum lumen (stent) area and dissection were associated with restenosis. Nevertheless, there is limited and heterogeneous evidence regarding the usefulness and Predictability of IVUS in patients with peripheral arterial disease in the femoropopliteal artery, especially in long-term patency and as a predictor of declining patency. The optimal role of IVUS in such patients should be elucidated in the future.

The impact of plaque morphology in patients with peripheral artery disease on vessel dissection: an intravascular ultrasound observational study

Drug-coated balloon (DCB) is now available for endovascular treatment (EVT) of superficial femoral arteries (SFA). Although it has been reported that severe vessel dissection after balloon angioplasty was risk of restenosis, it is difficult to predict the vessel dissection patterns before balloon angioplasty. We investigated the correlation between plaque morphology and vessel dissection pattern after balloon angioplasty using the intravascular ultrasound (IVUS). A total of 73 de novo SFA lesions were enrolled in this study. IVUS examinations were measured at the minimum lumen area in the control angiogram. Plaque morphology, minimum lumen area (MLA) and vessel diameter at the same point were evaluated before and after the initial balloon angioplasty. Vessel dissection patterns after the initial balloon angioplasty were classified into 7 types (A to F). There were no severe dissection patterns which were more than type D dissection in this study. All patients were treated with DCB without any bailout stenting. No dissection was found in 35.6% (26/73). Type A, B and C dissections were seen in 17.8% (13/73), 40% (27/73) and 9.6% (7/73), respectively. Although there were no relations between plaque morphology and vessel dissection patterns (p = 0.547), the MLA with dissection was larger than that without dissection (5.78 mm² versus 4.63 mm², p = 0.032). Although the dissection patterns could not be predicted in non-severe (Non or A to C) dissection, our result might suggest that IVUS image has the potential to reduce severe dissection.