Efficacy of intravascular ultrasound in femoropopliteal stenting for peripheral artery disease with TASC II class A to C lesions

Intravascular Ultrasound Use is Associated with Improved Patency in Lower Extremity Peripheral Arterial Interventions

BACKGROUND

Intravascular ultrasound (IVUS) facilitates detailed visualization of endoluminal anatomy not adequately appreciated on conventional angiography. However, it is unclear if IVUS use improves clinical outcomes of peripheral vascular interventions (PVIs) for peripheral arterial disease. This study aimed to evaluate the impact of IVUS on 1-year outcomes of PVI in the vascular quality initiative (VQI).

METHODS

The VQI-PVI modules were reviewed (2016-2020). All patients with available 1-year follow-up after lower extremity PVI were included and grouped as IVUS-PVI or non-IVUS PVI based on use of IVUS. Propensity matching (1:1) was performed using demographics and comorbidities. One-year major amputation and patency rates were compared. A generalized estimating equation model was used to identify predictors of 1-year outcomes. Subgroup analysis based on Trans-Atlantic Intersociety Consensus (TASC) classification, treatment length and treatment modalities were performed using same modeling approaches.

RESULTS

There were 56,633 procedures (non-IVUS PVI = 55,302 vs. IVUS-PVI = 1,331) in 44,042 patients. Propensity matching yielded a total cohort of 1,854 patients matched (1:1), with no baseline differences. Lower extremity revascularization for claudication was performed in 60.4%, while one-third (33.9%) had chronic limb threatening ischemia (CLTI). IVUS was more commonly used for lesions >15 cm in length (46.6% vs. 43.3%) and for aortoiliac disease (31.8% vs. 27.2%). Rates of atherectomy and stenting were significantly higher with IVUS-PVI (21.1% vs. 16.8%), while balloon angioplasty was less common (13.5% vs. 24.4%). One-year patency was better with IVUS-PVI (97.7% vs. 95.2%, P = 0.004). On subgroup analysis, IVUS (odds ratio [OR] 2.20, 95% confidence interval [CI] 1.29-3.75) was associated with improved patency in CLTI patients, TASC C or D lesions, and treatment length >15 cm. Adjunctive IVUS use during PVI did not significantly impact 1-year amputation (OR 1.7, 95% CI 0.78-3.91). On multivariable regression, adjunctive use of IVUS (OR 2.46 95% CI 1.43-4.25) and aortoiliac interventions (OR 2.91, 95% CI 1.09-7.75) were independent predictors of patency. Treatment modalities such as atherectomy, stenting or balloon angioplasty did not significantly impact patency at 1-year.

CONCLUSIONS

IVUS during lower extremity PVI is associated with improved 1-year patency, when compared to angiography alone. Certain subgroups, such as CLTI patients, lesions>15 cm, and TASC C or D lesions might benefit from adjunctive use of IVUS.

Intravascular ultrasound-guided drug-coated balloon angioplasty for femoropopliteal artery disease: a clinical trial

BACKGROUND AND AIMS

Drug-coated balloons (DCBs) have demonstrated favourable outcomes following endovascular therapy for femoropopliteal artery (FPA) disease. However, uncertainty remains whether the use of intravascular ultrasound (IVUS) can improve the outcomes of DCBs.

METHODS

This prospective, multicentre, randomized trial, conducted at seven centres in South Korea, compared the outcomes of IVUS-guided vs. angiography-guided angioplasty for treating FPA disease with DCBs. Patients were assigned to receive IVUS-guided (n = 119) or angiography-guided (n = 118) angioplasty using DCBs. The primary endpoint was 12-month primary patency.

RESULTS

Between May 2016 and August 2022, 237 patients were enrolled and 204 (86.0%) completed the trial (median follow-up; 363 days). The IVUS guidance group showed significantly higher primary patency [83.8% vs. 70.1%; cumulative difference 19.6% (95% confidence interval 6.8 to 32.3); P = .01] and increased freedom from clinically driven target lesion revascularization [92.4% vs. 83.0%; difference 11.6% (95% confidence interval 3.1 to 20.1); P = .02], sustained clinical improvement (89.1% vs. 76.3%, P = .01), and haemodynamic improvement (82.4% vs. 66.9%, P = .01) at 12 months compared with the angiography guidance group. The IVUS group utilized larger balloon diameters and pressures for pre-dilation, more frequent post-dilation, and higher pressures for post-dilation, resulting in a greater post-procedural minimum lumen diameter (3.90 ± 0.59 vs. 3.71 ± 0.73 mm, P = .03).

CONCLUSIONS

Intravascular ultrasound guidance significantly improved the outcomes of DCBs for FPA disease in terms of primary patency, freedom from clinically driven target lesion revascularization, and sustained clinical and haemodynamic improvement at 12 months. These benefits may be attributed to IVUS-guided optimization of the lesion before and after DCB treatment.

Impact of intravascular ultrasound-guided endovascular therapy on periprocedural outcomes in patients with lower-extremity artery disease

BACKGROUND

Although technological improvements in intravascular ultrasound (IVUS) may reduce technical failures in endovascular therapy (EVT), perioperative complications (POCs) associated with IVUS use may increase.

AIMS

This study investigated the impact of IVUS on periprocedural outcomes in symptomatic lower-extremity artery disease (LEAD) patients undergoing EVT.

METHODS

This study evaluated 28,088 symptomatic LEAD patients who underwent EVT between January 2021 and December 2021 using a prospective nationwide registry in Japan. Outcome measures included periprocedural outcomes, including technical failure and POCs. To compare outcomes with and without IVUS use, propensity score matching analysis was performed for overall and for each arterial region (aortoiliac [AI], femoropopliteal [FP], and infrapopliteal [IP] arteries) using a binary logistic regression model.

RESULTS

IVUS was used in 75%, 72%, and 37% of AI, FP, and IP lesions, respectively. After propensity matching extraction, the IVUS group had a tendency of lower technical failure rate than the non-IVUS group, although not statistically different (3.9% vs. 5.4%, p = 0.054), without an increase in the POC rate (1.8% vs. 1.6%, p = 0.54). Regarding the per-regional analysis, the technical failure rate of FP-EVT was significantly lower in the IVUS group (3.1% vs. 4.2%, p = 0.006), whereas those of AI-EVT (2.2% vs. 3.1%, p = 0.12) and IP-EVT (6.8% vs. 6.1%, p = 0.37) were not significantly different between the two groups. Furthermore, IVUS did not increase the POC rate for any region (AI-EVT: 1.3% vs. 1.3%, p = 1.00; FP-EVT: 1.8% vs. 1.7%, p = 0.75; and IP-EVT: 2.0% vs. 1.7%, p = 0.56).

CONCLUSION

The current study revealed that IVUS did not increase the POCs and technical failure for overall lesions but reduced the incidence of FP-EVT technical failure.

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.

Liquid Drug Delivery Approaches for the Treatment of Occlusive Arterial Disease: A Systematic Review

OBJECTIVE

Local Liquid drug (LLD) delivery devices have recently emerged as a novel approach to treat peripheral arterial disease. This systemic review aims to identify and evaluate the clinical utility of the most commonly used delivery devices.

METHODS

A systemic review was performed using the Medical Subjects Heading terms of "drug delivery," "liquid," "local," and "cardiovascular disease" in PubMed, Google Scholar, and Scopus.

RESULTS

Four commonly used delivery devices were identified, including (1) the Bullfrog Micro-Infusion Device, (2) the ClearWay RX Catheter, (3) the Occlusion Perfusion Catheter, and (4) the Targeted Adjustable Pharmaceutical Administration. All have shown to successfully deliver liquid therapeutic into the target lesion and have exhibited favorable safety and efficacy profiles in preclinical and clinical trials. The LLD devices have the ability to treat very long or multiple lesions with a single device, providing a more economical option. The safety profile in LLD clinical studies is also favorable in view of recent concerns regarding adverse events with crystalline-paclitaxel-coated devices.

CONCLUSION

There is clear clinical evidence to support the concept of local liquid delivery to treat occlusive arterial disease.

CLINICAL IMPACT

The 'leave nothing behind' strategy has been at the forefront of the most recent innovations in the field of interventional cardiology and vascular interventions. Although drug coated balloons have overcome limitations associated with plain old balloon angioplasty and peripheral stents, recent safety concerns and cost considerations have impacted their usage. In this review, various liquid drug delivery devices are presented, showcasing their capabilities and success in both preclinical and clinical settings. These innovative liquid delivery devices, capable of targeted delivery and their ability to be re-used for multiple treatment sites, may provide solutions for current unmet clinical needs.

Cost-effectiveness analysis of intravascular ultrasound-guided peripheral vascular interventions in patients with femoropopliteal peripheral artery disease

Background: Intravascular ultrasound (IVUS)-guided percutaneous transluminal angioplasty (PTA) might offer clinical benefits compared to angiography-guided PTA in patients with peripheral artery disease (PAD). A cost-effectiveness model was developed to examine the benefits and costs of IVUS-guided PTA versus angiography-guided PTA in PAD patients with femoropopliteal (FP) occlusive disease. Methods: A two-step model (a one-year decision tree followed by a lifetime semi-Markov model) was developed from a German healthcare payer perspective to estimate the costs and outcomes over a one-year and lifetime horizon. Clinical events included target lesion revascularization (TLR), amputation, and death. Transition probabilities and utility values were derived from published literature. Healthcare costs were based on German Diagnosis Related Groups (DRG) codes. Costs and outcomes were discounted at a rate of 3% per year. The incremental cost-effectiveness ratio (ICER) was calculated, and sensitivity analyses were performed to assess the robustness of the results. Results: In the one-year horizon, IVUS-guided PTA resulted in incremental quality-adjusted life-years (QALY) and costs of 0.02 and €919 per patient respectively, with a corresponding ICER of €45,195/QALY gained versus angiography-guided PTA. In the lifetime horizon, IVUS-guided PTA outperforms angiography-guided PTA; it was associated with a cost saving of €46 per patient and incremental QALY of 0.22. Utility value for post-TLR, as well as probabilities of death and TLR had the greatest impact on the one-year ICER, while cost of TLR and probabilities of TLR and amputation influenced the lifetime ICER most. The probability of IVUS-guided PTA being cost-effective at a willingness-to-pay (WTP) threshold of €50,000/QALY was 50.4% in the one-year horizon and increased to 85.9% in the lifetime horizon. Conclusions: In this analysis IVUS-guided PTA among patients with symptomatic FP atherosclerosis was cost-saving in a lifetime horizon from the German healthcare payer perspective.

The mid-term effect of intravascular ultrasound on endovascular interventions for lower extremity peripheral arterial disease: A systematic review and meta-analysis

OBJECTIVE

Intravascular ultrasound (IVUS) is an important adjunctive tool for patients with lower extremity peripheral arterial disease (PAD) undergoing endovascular therapy (EVT). The evidence regarding the advantages of IVUS use is evolving, and recent studies have reported conflicting results. We aimed to perform a meta-analysis to evaluate the efficacy of IVUS during angiography-guided EVT for patients with PAD.

METHODS

MEDLINE and EMBASE were searched through April 2023 to identify studies that investigated the outcomes of IVUS with angiography-guided EVT vs angiography-alone-guided EVT. The primary outcome was restenosis/occlusion rate; secondary outcomes were target lesion revascularization, major amputation, and mortality.

RESULTS

One randomized controlled trial and 14 observational studies, largely of moderate quality, were included, yielding a total of 708,808 patients with 709,189 lesions that were treated with IVUS-guided EVT (n = 101,405) vs angiography-alone (n = 607,784). Compared with angiography alone, IVUS-guided EVT was associated with a non-significant trend towards decreased restenosis/occlusion (relative risk [RR], 0.74; 95% confidence interval [CI], 0.54-1.00; I2 = 60%). Although the risk of target lesion revascularization and mortality were comparable (RR, 0.85; 95% CI, 0.65-1.10; I2 = 70%; RR, 1.01; 95% CI, 0.79-1.28; I2 = 43%, respectively), the use of IVUS was also associated with significantly lower risk of major amputation (RR, 0.74; 95% CI, 0.67-0.82; I2 = 47%). Subgroup analysis focusing on femoropopliteal disease demonstrated significantly higher patency (RR, 0.72; 95% CI, 0.52-0.98; I2 = 73%). However, superiority with major amputation was not observed.

CONCLUSIONS

IVUS-guided EVT for PAD may possibly be associated with a lower major amputation rate compared with angiography alone-guided EVT, although the difference in patency remained an insignificant trend in favor of IVUS-guided EVT. Adjunctive use of IVUS during EVT may be beneficial, and further prospective studies are warranted to delineate this relationship and the applicability of this technology in routine practice.

Below-the-Knee Endovascular Revascularization: A Position Statement

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

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.

Efficacy and utilization of intravascular ultrasound in office-based lower extremity endovascular interventions for peripheral arterial disease

OBJECTIVES

Intravascular ultrasound (IVUS) is a uniquely objective but underutilized imaging modality in the interventional treatment of peripheral arterial disease treatment. IVUS has been shown to improve device size selection and diagnose occult pathology difficult to see with routine angiography. We hypothesize that the use of IVUS in lower extremity endovascular intervention improves accuracy in stent and balloon size selection and minimizes contrast use.

METHODS

This is a retrospective case series performed at a single-institution outpatient center by two vascular surgeons from July 2016 through July 2017. We identified 94 total IVUS-assisted procedures. We collected data regarding demographics, balloon and stent size, IVUS-determined vessel diameter, pre-procedure and post-procedure ABI values, and contrast used during the procedure. An independent core laboratory was further utilized to characterize all IVUS and angiographic size vessel measurements.

RESULTS

For the 94 lower extremity IVUS-assisted interventions, the average patient age was 70±9 years old, with an average contrast use of 37.1 mL of Omnipaque 300. There was substantial improvement in pre- and post-procedure ABI (0.7±0.23 to 0.94±0.21). On analysis of average intraluminal IVUS vessel diameter to balloon angioplasty used, we had a correlation in size of 0.96±0.16 in our series. Additionally, in eight instances IVUS allowed for identification of a flow-limiting dissection with subsequent stenting.

CONCLUSIONS

Routine use of IVUS offers a powerful diagnostic paradigm that has the potential to significantly decrease contrast use and to improve objectivity in choosing appropriate vascular tools to maximize intra-procedural efficacy. The discovery of adverse findings not initially noticed on angiography further reinforces the value of IVUS utilization.

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.

Reproducibility of Femoropopliteal Artery Intravascular Ultrasound Imaging in Patients With Peripheral Artery Disease

Despite increased use of intravascular ultrasound (IVUS) during peripheral artery interventions, evidence for reproducibility of IVUS measurements and its relation to angiography is lacking. Forty cross-sectional IVUS images of the femoropopliteal artery from 20 randomly selected patients enrolled in the XLPAD (Excellence in Peripheral Artery Disease) registry who underwent peripheral artery interventions and met criteria based on IVUS consensus guidelines were independently assessed by 2 blinded readers. IVUS images from 6 patients (40 images) were selected for angiographic correlation and met criteria for identifiable landmarks (e.g., stent edge and bifurcation). Lumen cross-sectional area (CSA), external elastic membrane (EEM) CSA, luminal diameter, and reference vessel diameter were repeatedly measured. The Lumen CSA and EEM CSA intra-observer agreement by Spearman rank-order correlation (ρ) was >0.993, intraclass correlation coefficient was >0.997, and repeatability coefficient was <1.34. For the interobserver measurement of luminal CSA and EEM CSA, the ρ = 0.742 and 0.764; intraclass correlation coefficient = 0.888 and 0.885; and repeatability coefficient = 7.24 and 11.34, respectively. A Bland-Altman plot for lumen and EEM CSA showed good reproducibility. For angiographic comparison, the ρ for luminal diameter, luminal area, and vessel area were 0.419, 0.414, and 0.649, respectively. Femoropopliteal IVUS measurements showed strong intra-observer and interobserver agreement; IVUS and angiographic measurements did not demonstrate a similar strong agreement.

Intravascular Ultrasound Guidance During Peripheral Vascular Interventions: Long-term Clinical Outcomes and Costs From the Japanese Perspective

PURPOSE

The value of intravascular ultrasound (IVUS) guidance during peripheral vascular revascularization procedures is incompletely understood. Moreover, data on long-term clinical outcomes and costs are limited. The objective of this study was to compare outcomes and costs between IVUS and contrast angiography alone in patients undergoing peripheral revascularization procedures in Japan.

MATERIALS AND METHODS

This retrospective comparative analysis was performed using the Japanese Medical Data Vision insurance claims database. All patients undergoing revascularization for peripheral artery disease (PAD) between April 2009 and July 2019 were included. Patients were followed until July 2020, death, or a subsequent revascularization procedure for PAD. Two patient groups were compared: one undergoing IVUS imaging or the other contrast angiography alone. The primary end point was major adverse cardiac and limb events, including all-cause-mortality, endovascular thrombolysis, subsequent revascularization procedures for PAD, stroke, acute myocardial infarction, and major amputations. Total health care costs were documented over the follow-up and compared between groups, using a bootstrap method.

RESULTS

The study included 3956 patients in the IVUS group and 5889 in the angiography alone group. Intravascular ultrasound was significantly associated with reduced risk of a subsequent revascularization procedure (adjusted hazard ratio: 0.25 [0.22-0.28]) and major adverse cardiac and limb events (0.69 [0.65-0.73]). The total costs were significantly lower in the IVUS group, with a mean cost saving over follow-up of $18 173 [$7 695-$28 595] per patient.

CONCLUSION

The use of IVUS during peripheral revascularization provides superior long-term clinical outcomes at lower costs compared with contrast angiography alone, warranting wider adoption and fewer barriers to IVUS reimbursement for patients with PAD undergoing routine revascularization.

CLINICAL IMPACT

Intravascular ultrasound (IVUS) guidance during peripheral vascular revascularization has been introduced to improve the precision of the procedure. However, questions over the benefit of IVUS in terms of long-term clinical outcome and over cost have limited its use in everyday clinical practice. This study, performed in a Japanese health insurance claims database, demonstrates that use of IVUS provides a superior clinical outcome over the long term at a lower cost compared to angiography alone. These findings should encourage clinicians to use IVUS in routine peripheral vascular revascularization procedures and encourage providers to reduce barriers to use.

Amputation After Endovascular Therapy With and Without Intravascular Ultrasound Guidance: A Nationwide Propensity Score-Matched Study

BACKGROUND

Intravascular ultrasound (IVUS) provides precise intravascular information during endovascular therapy (EVT). However, the clinical efficacy of IVUS in patients who undergo EVT remains unknown. The present study aimed to determine whether the use of IVUS-guided EVT is associated with better clinical outcomes in a real-world setting.

METHODS

Using the Japanese Diagnosis Procedure Combination administrative inpatient database from April 2014 to March 2019, we identified patients diagnosed with atherosclerosis of arteries of extremities and underwent EVT (percutaneous endovascular transluminal angioplasty and thrombectomy for extremities or percutaneous endovascular removal). Propensity score matching analysis was performed to compare outcomes between the patients who underwent IVUS on the same day as the first EVT intervention (IVUS group) and the others (non-IVUS group). The primary outcome was major and minor amputation for extremities within 12 months of the first EVT procedure. Secondary outcomes were bypass surgery, stent grafting, reintervention, all-cause death, readmission, and total hospitalization costs within 12 months of the first EVT procedure.

RESULTS

Among 85 649 eligible patients, 50 925 (59.5%) were IVUS group. After propensity score matching, the IVUS group had significantly lower incidence of 12-month amputation compared with the non-IVUS group (6.9% in the IVUS group versus 9.3% in the non-IVUS group; hazard ratio, 0.80 [95% CI, 0.72-0.89]). Compared with the non-IVUS group, the IVUS group showed a lower risk of bypass surgery and stent grafting and decreased total hospitalization costs, while a higher risk of reintervention and readmission. No significant differences in all-cause death were found between the 2 groups.

CONCLUSIONS

In this retrospective study, IVUS-guided EVT was associated with a lower amputation risk than non-IVUS-guided EVT. Our findings should be interpreted carefully because of the limitations of an observational study using administrative data. Further studies are warranted to confirm whether IVUS-guided EVT leads to decreased amputations.

Temporal Trends, Practice Variation, and Associated Outcomes With IVUS Use During Peripheral Arterial Intervention

BACKGROUND

Intravascular ultrasound (IVUS) has been shown in limited prospective studies to improve procedural outcomes for patients undergoing lower extremity peripheral arterial intervention (PVI).

OBJECTIVES

The authors aimed to study temporal trends, practice variation, and associated outcomes with the use of IVUS during PVI among Medicare beneficiaries.

METHODS

All PVIs performed from 2016 to 2019 among Medicare beneficiaries aged >65 years were included. Temporal trends in IVUS use were stratified by procedural location (inpatient, outpatient, or ambulatory surgery center [ASC]/office-based laboratory [OBL]) and physician specialty. The primary outcome was major adverse limb events (MALE). Inverse probability weighting was used to account for differences in baseline characteristics. Cox regression with competing risks was used to estimate weighted hazard ratios.

RESULTS

During the study period, 543,488 PVIs were included, of which 63,372 (11.7%) used IVUS. A substantial growth in IVUS use was observed, which was driven by procedures performed in ASCs/OBLs (23.6% increase from quarter 1 of 2016 through quarter 4 of 2019). Among operators who used IVUS, there was also notable variation in use (median operator use 5.4% of cases; IQR: 2.2%-15.0%; range, <1%-100%). In weighted analysis, IVUS use during PVI was associated with a lower risk of MALE through a median of 514 days (adjusted hazard ratio: 0.73; 95% CI: 0.70-0.75; P < 0.0001).

CONCLUSIONS

In contemporary nationwide data, IVUS use during PVI has increased since 2016, driven by growth in the ASC/OBL setting. However, there remains substantial variation in operator practice. When used during PVI, IVUS was associated with a lower risk of short- and long-term MALE.

Intravascular ultrasound-based decision tree model for the optimal endovascular treatment strategy selection of femoropopliteal artery disease-results from the ONION Study

BACKGROUND

The role of catheter-based imaging in peripheral interventions for lower extremity artery disease (LEAD) has increased with percutaneous interventions. To clarify the relation between intravascular ultrasound (IVUS) information and procedure selection strategy for endovascular treatment therapy (EVT) of the femoropopliteal artery in the real-world clinical settings wherein new endovascular technologies (NETs), including drug-coated balloon (DCB), drug-eluting stent (DES), and covered stent-graft (CS). Our retrospective multicenter analysis examined symptomatic 970 patients treated by EVT for de novo femoropopliteal lesions with IVUS guidance. The decision tree analysis was performed retrospectively to determine the association of IVUS and angiography parameters with the strategy selection of endovascular procedures. We divided the study population according to the developed tree, and identified the most popular strategy selection in each subgroup. We finally examined whether the restenosis risk would be different among respective subgroups of the tree.

RESULTS

During the study periods, plain old balloon angioplasty, DCB, and bare nitinol stent were most frequently selected (25.3%, 23.9%, and 23.8%, respectively). The drug-eluting stent (DES), covered stent (CS), and spot stent strategies were used in 7.3%, 11.5%, and 8.1%. NETs had the lowest restenosis risk in the overall population. The decision tree had a depth of six branches and divided the patients into 11 subgroups by IVUS and angiography parameters. The restenosis rate was similarly low among these 11 subgroups when the most popular NET in each subgroup was selected (P = 0.94).

CONCLUSIONS

The use of IVUS data along with angiography data would standardize the selection of endovascular procedures and can improve patency outcomes if NETs are used properly.

What should we expect from intravascular ultrasound use for complex femoropopliteal lesions?

In this review article, we summarize the clinical benefit of intravascular ultrasounds (IVUS) in the endovascular therapy (EVT) of complex femoropopliteal (FP) lesions. Due to the development of novel FP-dedicated devices, outcomes of FP-EVT have been improved. As a result, revascularization methods for the FP lesions have shifted to EVT. However, the long-term durability in complex FP lesions has not yet reached that of bypass surgery using autogenous vein. Strategies for EVT of complex FP lesions are still inconsistent and have room for improvement. Long-term results generally depend on the patient and lesion backgrounds but are also affected by the quality of the procedure. Previous reports have shown IVUS evaluation can better assess vessel size compared to conventional angiographic evaluation. In contrast to angio-guided EVT, which evaluates vessel size by inner diameter, IVUS can be evaluated it with an external elastic membrane, which leads to the selection of a more appropriate (basically, larger) size device. Conversely, angiographic evaluation underestimates the vessel size, suggesting that it may lead to insufficient result. Furthermore, IVUS can also assess the adequate guidewire route, presence of severe dissection etc. As the evidence so far shows, the use of IVUS may improve the quality of EVT procedure, resulting in improved long-term outcomes. In conclusion, despite the widespread use of IVUS in FP-EVT practice, it still conditionally applied. The purpose of IVUS in the EVT of complex FP lesions should be clarified. More evidence regarding the IVUS in complex FP lesions is needed.

Intravascular US: Applications in Interventional Radiology

Interventional radiology applications of intravascular US (IVUS) continue to expand, complementing intraprocedural angiography and providing a unique vantage from which to guide endovascular interventions. Vascular pathologic conditions become sonographically visualized rather than inferred from the planar appearance of the opacified vascular lumen. Perivascular targets become sonographically visualized rather than approximated on the basis of fluoroscopic landmarks. The authors introduce broad categories of IVUS catheters, namely radial and side-firing varieties, as well as prevailing options for each and their technical specifications. Common applications within interventional radiology are covered in a systems approach, including deep venous thrombosis, May-Thurner syndrome, nutcracker syndrome, transjugular intrahepatic portosystemic shunts, aortic interventions, peripheral arterial disease, and endovascular or perivascular biopsy. Discussions are accompanied by technical pearls from the authors, and summarized evidence where IVUS has been shown to reduce procedural time, intravascular contrast agent dose, radiation exposure, and morbidity in each space is presented. Finally, emerging applications and future directions are discussed. ^©RSNA, 2022.

Intravascular ultrasound guidance for lower extremity arterial and venous interventions

This review details the utility of intravascular ultrasound (IVUS) for the management of peripheral artery and venous disease. The purpose of this document is to provide an update in the use of IVUS in peripheral arterial and venous pathology and demonstrate the use of IVUS as a practical diagnostic imaging procedure to evaluate and treat peripheral vascular disorders. IVUS, a diagnostic tool that relies on sound waves to produce precise images of the vessel being evaluated, was originally introduced to the medical community for the purposes of peripheral artery imaging, though it was quickly adapted for coronary interventions with positive outcomes. The utility of IVUS includes vessel measurement, pre- and post-procedural planning, treatment optimisation, and detection of thrombus, dissection or calcium severity. While angiography remains the standard imaging approach during peripheral intervention, multiple observational studies and small prospective trials have shown that in comparison, IVUS provides more accurate imaging detail, which may improve procedural outcomes. IVUS can also address limitations of angiography, including the need to administer contrast medium and eliminate the ambiguity associated with other forms of imaging. This review provides contemporary examples of where IVUS is being used during peripheral intervention as well as representative imaging to serve as a resource for the practising clinician.

State-of-the-Art Endovascular Therapies for the Femoropopliteal Segment: Are We There Yet?

Peripheral arterial disease is an increasingly prevalent condition with significant associated morbidity, mortality, and health care expenditure. Endovascular interventions are appropriate for most patients with either ongoing symptoms of intermittent claudication despite lifestyle and medical optimization or chronic limb-threatening ischemia. The femoropopliteal segment is the most common arterial culprit responsible for claudication and the most commonly revascularized segment. Endovascular approaches to revascularization of the femoropopliteal segment are advancing with an evolving landscape of techniques for arterial access, device-based therapies, vessel preparation, and intraprocedural imaging. These advances have been marked by debate and controversy, notably related to the safety of paclitaxel-based devices and necessity of atherectomy. In this review, we provide a critical overview of the current evidence, practice patterns, emerging evidence, and technological advances for endovascular intervention of the femoropopliteal arterial segment.

Intravascular ultrasound in peripheral venous and arterial interventions: A contemporary systematic review and grading of the quality of evidence

Although angiography has been the primary imaging modality used in peripheral vascular intervention, this technique has major limitations due to the evaluation of three-dimensional vessels in two dimensions. Intravascular ultrasound (IVUS) is an important adjunctive tool that can address some of these limitations. This systematic review assesses the appropriateness of IVUS as an imaging modality for guiding peripheral intervention through evidence collection and clinical appraisal of studies. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a cohort of 48 studies (29 arterial; 19 venous) detailing IVUS use in peripheral vascular intervention were extracted. Qualitative assessment of the studies evaluated pre- and postprocedure efficacy of IVUS and revealed that IVUS-guided peripheral intervention in arterial and venous diagnosis and treatment was superior to other imaging techniques alone. Each study in the cohort was further assessed for reliability and validity using the Oxford Centre for Evidence Based Medicine (CEBM) level of evidence scale. The majority of both arterial (79.3%) and venous (73.7%) studies received a 2b rating, the second highest level of evidence rating. The evidence to date indicates that IVUS results in better clinical outcomes overall and should be more widely adopted as an adjunctive imaging modality during peripheral intervention. (PROSPERO Registration No.: CRD42021232353).

How Much Debulking with Atherectomy is Enough When Treating Infrainguinal Arterial Interventions? The Balance Between Residual Stenosis and Adventitial Injury

Atherectomy is an effective vessel prepping device but not all atherectomy devices are equal. The depth of vessel injury and residual narrowing vary considerably among atherectomy devices with significant implications on outcome. Precision imaging is critical to optimize outcome using atherectomy as a vessel prepping technique. Prospective trials need to test the hypothesis that precision imaging has a significant impact on how operators approach the treatment of infrainguinal arterial disease.

The Impact of Intravascular Ultrasound on Femoropopliteal Artery Endovascular Interventions: A Randomized Controlled Trial

OBJECTIVES

The aim of this study was to investigate whether the addition of intravascular ultrasound (IVUS) guidance during femoropopliteal artery interventions reduced the rate of binary restenosis within 12 months compared with angiographic guidance alone.

BACKGROUND

IVUS is more accurate than angiography for assessment of vessel size and disease severity. Low-level studies suggest that the use of IVUS in femoropopliteal endovascular interventions improves outcomes, but currently, no level 1 evidence exists.

METHODS

This was a prospective single-center trial of 150 patients undergoing femoropopliteal endovascular intervention, randomized (1:1) to guidance by angiography or angiography and IVUS. The primary outcome measure was freedom from binary restenosis, on duplex ultrasound, within 12 months. Secondary outcomes included clinically driven target lesion revascularization, disagreements in imaging findings between modalities, and changes in treatment caused by IVUS.

RESULTS

Freedom from binary restenosis at 12 months was significantly higher in the IVUS group (72.4% vs 55.4%; P = 0.008). There was no significant difference between groups for clinically directed target lesion revascularization (84.2% and 82.4%; P = 0.776). Mean vessel diameter was significantly larger with IVUS (5.60 mm vs 5.10 mm; P < 0.001). A change in treatment occurred caused by IVUS in 79% of cases. Binary restenosis was lower in the IVUS group for cases treated with drug-coated balloons (9.1% vs 37.5%; P = 0.001).

CONCLUSIONS

The use of IVUS resulted in a significant reduction in the rate of restenosis after endovascular intervention. This is the first randomized controlled trial to demonstrate that IVUS improves outcomes in femoropopliteal interventions. This benefit may primarily relate to cases treated with drug-coated balloons. (Does the use of intravascular ultrasound improve outcomes of endovascular interventional procedures for peripheral vascular disease of the superficial femoral artery or popliteal artery?; ACTRN12614000006640).

Use of Intravascular Ultrasound During First-Time Femoropopliteal Peripheral Vascular Interventions Among Medicare Beneficiaries

BACKGROUND

Intravascular ultrasound (IVUS) may be a useful adjunct to lower extremity peripheral vascular interventions (PVI) in certain clinical scenarios. We aimed to identify patient- and physician-level characteristics associated with the use of IVUS during first-time femoropopliteal PVI.

METHODS

We included all Medicare beneficiaries undergoing elective femoropopliteal PVI for claudication or chronic limb-threatening ischemia between 01/01/2019 and 12/31/2019. We excluded patients with prior open or endovascular femoropopliteal intervention and all physicians performing ≤10 PVI during the study period. We calculated the proportion of patients who had IVUS performed as part of their index PVI for each physician. Hierarchical logistic regression was used to evaluate patient- and physician-level factors associated with use of IVUS.

RESULTS

We identified 58,552 patients who underwent index femoropopliteal PVI, of whom 11,394 (19%) received IVUS. A total of 1,628 physicians performed >10 procedures during the study period, with IVUS utilization ranging from 0-100%. After hierarchical regression, claudication (versus chronic limb-threatening ischemia: OR 1.23, 95% CI 1.11-1.36), stenting (versus angioplasty alone: OR 1.57, 1.33-1.86) and atherectomy (versus angioplasty alone: OR 2.09, 1.83-2.39) were associated with higher odds of IVUS utilization. Higher-volume providers (tertile 3 vs. tertile 1: OR 3.78, 2.43-5.90) and those with high rates of service provided in an office-based laboratory (tertile 3 vs. tertile 1: OR 10.72, 6.78-19.93) were more likely to utilize IVUS. Radiologists (OR 11.23, 5.96-21.17) and cardiologists (OR 1.97, 1.32-2.93) used IVUS more frequently than vascular surgeons.

CONCLUSIONS

Wide variability exists in the use of IVUS for first-time femoropopliteal PVI. The association of IVUS with claudication, atherectomy, and office-based laboratories raises concern about its potential overuse by some physicians.

The safety and efficacy of different endovascular treatments for in-stent restenosis of the femoropopliteal artery: A network meta-analysis

Purpose: Femoropopliteal artery in-stent restenosis (ISR) remains a challenging treatment. We performed a network meta-analysis (NWM) for femoropopliteal artery ISR to explore the safety and efficacy of endovascular therapeutic strategies. Methods: The MEDLINE, Embase, Web of Science, and Cochrane databases were used as data sources. The network meta-analysis (NWM) approach used random-effects models based on the frequentist framework. We compared technical success rate, primary patency, target lesion revascularization (TLR), and major amputation at the 12-month follow-up for femoropopliteal artery ISR. Results: In total, 14 eligible studies (10 prospective and four retrospective; 1348 patients; and eight treatment modalities - standard balloon angioplasty (SBA), drug-coated balloon (DCB), peripheral cutting balloon angioplasty (PCBA), Viabahn endoprosthesis (VBE), directional atherectomy (DA), excimer laser atherectomy (ELA), and combinations - were included. The primary patency rates (at 6 months) were significantly higher for DCB and ELA+DCB than for SBA and ELA+SBA. ELA+DCB had higher primary patency rates (at 12 months) than ELA+SBA and SBA. The technical success rates were significantly lower for DCB and SBA than for VBE. The major amputation rates were significantly lower for ELA+DCB than for DCB. Based on the surface values under the cumulative ranking curve (SUCRA), ELA+DCB was considered the best treatment in terms of primary patency at 6 months (SUCRA = 91.1), primary patency at 12 months (SUCRA = 82.3), and TLR (SUCRA = 83.4). Conclusion: ELA+DCB showed positive encouraging results in primary patency (6, 12 months), TLR, and major amputation in femoropopliteal ISR. The efficacy and safety of ELA+DCB are worthy of further investigation. (PROSPERO Registration No.: CRD42021246674).

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.

Comparison of angiographic and intravascular ultrasound vessel measurements in infra-popliteal endovascular interventions: The below-the-knee calibration study

BACKGROUND

Endovascular revascularization (ER) via percutaneous transluminal angioplasty (PTA) and stenting are viable options for revascularization in below-the-knee (BTK) peripheral arterial disease. Two-dimensional angiography has been the standard of practice for estimating vessel size and selecting treatment devices during ER. However, in other vascular territories, intravascular ultrasound (IVUS) offers better visualization of the lumen dimensions.

PURPOSE

To compare angiographic and intravascular ultrasound reference vessel (lumen) measurements in below-the-knee peripheral artery interventions.

METHODS

20 consecutive patients were enrolled in the BTK Calibration study from 2 sites in the United States and Australia. Patients with at least one diseased segment in a native infra-popliteal artery (below-the-knee) and a clinical indication for endovascular therapy (EVT) were included with no limitations with regards to vessel diameter or lesion length. Digital subtraction angiography and intravascular ultrasound imaging were collected pre-and post-percutaneous transluminal angioplasty and images were sent to an independent Core lab for standardized quantitative analysis of the normal-looking reference vessel dimensions when available. The results were presented as least square means with 95% confidence intervals and a p-value of <0.05 was considered as significant.

RESULTS

The overall (N = 19) mean reference vessel diameter for QVA was 2.98 ± 1.24 vs. 3.47 ± 0.72 for IVUS (mean difference was -0.50, (95% CI: -0.80, -0.20; p = 0.14). As expected in the proximal segments (N = 12), the mean reference vessel diameters were larger: for QVA was 3.17 ± 1.34 vs. 3.55 ± 0.76 in IVUS, (mean difference was -0.38, (95% CI:-0.79,0.03; p = 0.40); while in the distal segments (N = 7), mean reference vessel diameters were smaller: for QVA was 2.64 ± 1.06 vs. 3.33 ± 0.67 in IVUS, (mean difference was -0.69, (95% CI:-1.04,-0.34; p = 0.17). We observed a greater degree of acute gain in cases where the treatment balloon size correlated with the IVUS measured reference size.

CONCLUSION

Angiography underestimates infrapopliteal reference vessel lumen size even when quantitatively assessed. Adjunctive IVUS imaging use in guiding BTK procedures could help ensure adequate sizing and possibly impact immediate post-procedure indices.

Mobile Health-Based Thermometer for Monitoring Wound Healing After Endovascular Therapy in Patients With Chronic Foot Ulcer: Prospective Cohort Study

BACKGROUND

Foot temperature may increase after endovascular therapy, but the relationship between foot temperature and wound healing is unclear.

OBJECTIVE

This study was performed to evaluate the feasibility of a mobile health (mHealth)-based thermometer for foot temperature monitoring in patients with chronic foot ulcer before and after endovascular therapy and to determine the association between temperature change and wound healing time.

METHODS

This was a prospective cohort study. Patients who had a chronic foot ulcer (>3 months) and underwent endovascular therapy between June 2019 and December 2019 were included. The participants received standard medical care and endovascular therapy for revascularization. The mHealth-based thermometer, composed of 4 temperature-sensing chips, was put on the foot before and after endovascular therapy. Data from the chips were transferred to an associated mobile phone app via Bluetooth. Wound healing time was estimated using the Kaplan-Meier method, and the associations between baseline characteristics and clinical outcomes were evaluated using a Cox proportional hazard model.

RESULTS

A total of 163 patients with chronic foot ulcer who underwent endovascular therapy were enrolled and followed up until wound healing was complete or for 180 days. The mean foot temperature before endovascular therapy was 30.6 (SD 2.8 °C). Foot temperature increased significantly (mean 32.1 °C, SD 2.8 °C; P=.01) after the procedure. Wound healing time was significantly different in the Kaplan-Meier curves of the patient group with temperature changes ≥2 °C and the group with temperature changes ≤2 °C (log-rank P<.001). A foot temperature increase ≥2 °C after endovascular therapy was associated with increased wound healing in univariate analysis (hazard ratio [HR] 1.78, 95% CI 1.24-2.76, P=.02), and the association remained significant in multivariate analysis (HR 1.69, 95% CI 1.21-2.67, P=.03).

CONCLUSIONS

The mHealth-based thermometer was feasible and useful for foot temperature monitoring, which may provide health care professionals with a new endpoint for endovascular therapy. Foot temperature increases ≥2 °C after endovascular therapy were associated with faster wound healing in patients with chronic foot ulcer. Further studies are needed, however, to confirm these findings.

Clinical impact of intravascular ultrasound-guided balloon angioplasty in patients with chronic limb threatening ischemia for isolated infrapopliteal lesion

BACKGROUND

To estimate the impact of intravascular ultrasound (IVUS) in patients with chronic limb-threatening ischemia (CLTI) who underwent balloon angioplasty for isolated infrapopliteal lesion.

METHODS

The study was performed as a single-center, prospective maintained database, retrospective analysis. Between January 2013 and December 2018, consecutive 155 CLTI patients (155 limbs) who primarily underwent balloon angioplasty for de novo isolated infrapopliteal atherosclerotic lesions with Rutherford category class 4 or 5 were identified (IVUS-guided: 92 patients, angio-guided: 63 patients) and included in the analysis. We compared clinical outcomes in IVUS-guided group with that in angio-guided group. The primary endpoint was limb salvage without any reintervention. The main secondary endpoints were wound healing rate and time to wound healing in the tissue loss group.

RESULT

Patient and limb characteristics were similar between the two groups. The IVUS-guided group was treated with a larger balloon size for all types of below-the-knee vessel (p < .001), although lesion characteristics, including the QVA-measured vessel diameter, were similar between the two groups. The IVUS-guided group had a higher rate of limb salvage without any reintervention than the angio-guided group (p = 0028). Whereas limb salvage and overall survival was not significantly different. Wound healing was significantly earlier and the time to wound healing was significantly shorter (84 ± 55 days vs. 135 ± 118 days, p = .007) in the IVUS-guided group.

CONCLUSION

Limb salvage rate without any reintervention in IIVUS-guided balloon angioplasty group was significantly higher than that in angio-guided balloon angioplasty group in patients with CLTI due to isolated infrapopliteal disease.

Intravascular Ultrasound in the Endovascular Treatment of Patients With Peripheral Arterial Disease: Current Role and Future Perspectives

Over the last decade, intravascular ultrasound (IVUS) has emerged as a useful adjunctive tool to angiography in an increasing number of catheter-based procedures for peripheral arterial disease (PAD). IVUS catheters offer accurate cross-sectional imaging of arterial vessels with high dimensional accuracy and provide accurate information about lesion morphology. IVUS enables assessment of the plaque morphology, vessel diameter, and the presence of arterial dissections. Furthermore, IVUS is able to properly guide the best choice of appropriate percutaneous transluminal angioplasty (PTA) technique, guide the delivery of different devices, and assess the immediate result of any endovascular intervention. In the present review, the role of IVUS for PAD will be discussed, specifically the applications of IVUS technology during interventional procedures including PTA, stent sizing, crossing total occlusion, assessing residual narrowing and stent apposition and expansion, and atherectomy. Future perspectives of IVUS-guided treatments and cost-effectiveness of the systematic use of IVUS during endovascular interventions will be also discussed.

Prediction Model for Freedom from TLR from a Multi-study Analysis of Long-Term Results with the Zilver PTX Drug-Eluting Peripheral Stent

Purpose

Develop a prediction model to determine the impact of patient and lesion factors on freedom from target lesion revascularization (ffTLR) for patients who are candidates for Zilver PTX drug-eluting stent (DES) treatment for femoropopliteal lesions.

Methods

Patient factors, lesion characteristics, and TLR results from five global studies were utilized for model development. Factors potentially associated with TLR (sex, age, diabetes, hypertension, hypercholesterolemia, renal disease, smoking status, Rutherford classification, lesion length, reference vessel diameter (RVD), popliteal involvement, total occlusion, calcification severity, prior interventions, and number of runoff vessels) were analyzed in a Cox proportional hazards model. Probability of ffTLR was generated for three example patient profiles via combinations of patient and lesion factors. TLR was defined as reintervention performed for ≥ 50% diameter stenosis after recurrent clinical symptoms.

Results

The model used records from 2227 patients. The median follow-up time was 23.9 months (range: 0.03–60.8). The Kaplan–Meier estimates for ffTLR were 90.5% through 1 year and 75.2% through 5 years. In a multivariate analysis, sex, age, Rutherford classification, lesion length, RVD, total occlusion, and prior interventions were significant factors. The example patient profiles have predicted 1-year ffTLRs of 97.4, 92.3, and 86.0% and 5-year predicted ffTLRs of 92.8, 79.5, and 64.8%. The prediction model is available as an interactive web-based tool (https://cooksfa.z13.web.core.windows.net).

Conclusions

This is the first prediction model that uses an extensive dataset to determine the impact of patient and lesion factors on ffTLR through 5 years and provides an interactive web-based tool for expected patient outcomes with the Zilver PTX DES.

Clinical Trial Registrations

Zilver PTX RCT unique identifier: NCT00120406; Zilver PTX single-arm study unique identifier: NCT01094678; Zilver PTX China study unique identifier: NCT02171962; Zilver PTX US post-approval study unique identifier: NCT01901289; Zilver PTX Japan post-market surveillance study unique identifier: NCT02254837.

Levels of Evidence

Zilver PTX RCT: Level 2, randomized controlled trial; Single-arm study: Level 4, large case series; China study: Level 4, case series; US post-approval study: Level 4, case series Japan PMS study: Level 4, large case series.

Electronic supplementary material

The online version of this article (10.1007/s00270-020-02648-6) contains supplementary material, which is available to authorized users.

Intravascular Ultrasound Imaging During Aortoiliac Stenting: No Impact on Outcomes at 1 Year

PURPOSE

To investigate the effect of intravascular ultrasound (IVUS) imaging use on clinical outcomes after aortoiliac stenting in patients with peripheral artery disease (PAD).

MATERIALS AND METHODS

Subjects for this retrospective analysis were derived from the OMOTENASHI registry database, which contained 803 symptomatic PAD patients (Rutherford categories 2-4) who were treated with self-expanding stent implantation for aortoiliac atherosclerotic lesions at 61 centers in Japan between January 2014 and April 2016. Of the 803 patients, 545 (67.9%) patients (mean age 73±9 years; 453 men) underwent IVUS-supported stent implantation and were compared with the 258 patients (mean age 73±8 years; 217 men) treated without IVUS. A propensity score analysis of 138 matched pairs was conducted to compare treatment strategies and clinical outcomes between patients having IVUS-supported endovascular therapy and those treated without IVUS.

RESULTS

Endovascular strategies and postoperative medications were not significantly different between the IVUS and no-IVUS groups. A procedure time under 1 hour was less frequent in the IVUS group, which had a longer fluoroscopy time. The 12-month restenosis rate was not significantly different between the 2 groups [10.2% (95% CI 6.9 to 14.9%) vs 10.3% (95% CI 5.4 to 18.6%), p=0.99]. There was no interaction between baseline characteristics and the association of IVUS use with restenosis risk.

CONCLUSION

Propensity score matching analysis revealed that duration and fluoroscopy time during IVUS-supported procedures were significantly longer than in cases without IVUS use, whereas the 12-month restenosis rate was not significantly different between the groups. IVUS use in aortoiliac lesions may be unnecessary.

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

BACKGROUND

The risk of restenosis after intervention is higher in femoropopliteal than in aortoiliac lesions. However, the appropriate endovascular therapy (EVT) for preventing restenosis after intervention for femoropopliteal lesions remains unknown. This study aimed to elucidate the relationship between lesion characteristics and patency after EVT using intravascular ultrasound (IVUS) measurement and to determine the predictors of restenosis on IVUS.Methods and Results:This prospective observational study was performed at 18 Japanese centers. We evaluated the lesion characteristics before and after EVT for femoropopliteal lesion using IVUS. Angiographic or duplex ultrasound follow-up was performed at 1 year after EVT. A total of 263 lesions underwent EVT between December 2016 and December 2017. In total, 20 lesions (8 cases of isolated common femoral artery lesion and 12 cases of restenosis lesion) were excluded, and 243 lesions were enrolled in this study. A total of 181 lesions were treated with stent placement, and 62 lesions were treated only with balloon angioplasty. In the case of stent use, a larger distal plaque burden was associated with restenosis, while a lower calcification angle was associated with higher patency in the case of balloon angioplasty alone.

CONCLUSIONS

The factors related to patency differed depending on the treating modality. The findings suggest that IVUS is a useful tool for predicting patency because it can provide a more accurate evaluation after EVT for femoropopliteal lesions.

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

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

Combination therapy of heparin-bonded covered stent and bare-nitinol stent assessed by intravascular ultrasound

To examine clinical outcomes for combination therapy of heparin-bonded covered stent [VIABAHN™ stent (VIA)] and bare-nitinol stent (BNS), and to determine independent predictors of restenosis after VIA implantation assessed by intravascular ultrasound (IVUS). A retrospective analysis was conducted on VIA use in the femoropopliteal artery of 71 patients (81 lesions) treated between June 2012 and November 2018. We divided the treated lesions into two groups; that is, whether BNS was added at the proximal site of the VIA or not (combination of VIA and BNS group [COM; n = 21] vs. VIA group [n = 60]). The median follow-up duration was 21.6 months (interquartile range, 13.2-28.8 months). Restenosis at 2 years was observed in 5 lesions (33%) in COM group and 17 lesions (38%) in VIA group (log-rank, P = 0.74). In VIA group, 14 lesions developed restenosis within 12 months. Multivariate logistic regression analysis of VIA group revealed that the proximal plaque burden was an independent predictor of restenosis within 12 months after VIA implantation (odds ratio 1.15, 95% confidence interval 1.01-1.30, P = 0.01), with the optimal cutoff value of 43% (area under the receiver operator characteristic curve 0.79, sensitivity 91%, specificity 69%). A remaining plaque of > 43% at the proximal reference segment was an independent predictor of restenosis after VIA implantation. When residual stenosis is observed at the proximal site of SFA after VIA implantation, combination therapy of VIA and BNS would be an optimal management.

Utility of Intravascular Ultrasound in Peripheral Vascular Interventions: Systematic Review and Meta-Analysis

Objectives:

We sought to compare outcomes between intravascular ultrasound– (IVUS) versus angiography (AO)-guided peripheral vascular interventions (PVIs). Introduction: Intravascular ultrasound facilitates plaque visualization and angioplasty during PVIs for peripheral arterial disease. It is unclear whether IVUS may improve the durability of PVIs and lead to improved clinical outcomes.

Methods:

This is a study-level meta-analysis of observational studies. The primary end points of this study were rates of primary patency and reintervention. Secondary end points included rates of vascular complications, periprocedural adverse events, amputations, technical success, all-cause mortality, and myocardial infarction.

Results:

Eight observational studies were included in this analysis with 93 551 patients. Mean follow-up was 24.2 ± 15 months. Intravascular ultrasound–guided PVIs had similar patency rates when compared with AO-guided PVIs (relative risk [RR]: 1.30, 95% confidence interval [CI]: 0.99-1.71, P = .062). There was no difference in rates of reintervention in IVUS-guided PVIs when compared to non-IVUS-guided PVIs (RR: 0.41, 95% CI: 0.15-1.13, P = .085). There is a lower risk of periprocedural adverse events (RR: 0.81, 95% CI: 0.70-0.94, P = .006) and vascular complications (RR: 0.81, 95% CI: 0.68-0.96, P = .013) in the IVUS group. All-cause mortality (RR: 0.76, 95% CI: 0.56-1.04, P = .084), amputation rates (RR 0.83, 95% CI: 0.32-2.15, P = .705), myocardial infarctions (RR: 1.19, 95% CI: 0.58-2.41, P = .637), and technical success (RR: 1.01, 95% CI: 0.86-1.19, P = .886) were similar between the groups. Conclusions: Intravascular ultrasound–guided PVIs had similar primary patency and reintervention when compared with AO-guided PVIs with significantly lower rates of periprocedural adverse events and vascular complications in the IVUS-guided group.

IVUS Assessment of the Crossing Pathway of an Intraluminal Reentry Device Used in the Primary Treatment of Infrainguinal Chronic Total Occlusions

Purpose: To examine with intravascular ultrasound (IVUS) the crossing pathways of the TruePath reentry device during primary antegrade recanalization of infrainguinal chronic total occlusions (CTOs). Methods: Between July 2017 and September 2018, a prospective multicenter study enrolled 143 consecutive patients (mean age 75±9 years; 101 men) with 146 CTOs treated in an antegrade approach using the TruePath reentry device with IVUS assessment of the crossing pathway in successful cases. Outcome measures were complete success (reentry device reached the distal true lumen), assisted success (reentry device use followed by a conventional guidewire to reach the distal true lumen), reentry device crossing route by IVUS assessment, and procedure- and device-related complications. Regression analyses were employed to identify any relevant associations between baseline patient variables and the outcome measures; results are presented as the odds ratio (ORs) and 95% confidence interval (CI). Results: Complete success was achieved in 82 (56.2%) lesions; any success (complete plus assisted) was documented in 117 (80.1%) lesions. Four (3%) perioperative device-related complications were observed. The crossing route was intraplaque for most of the total crossing distance in both complete success cases (95.3%±13.2%) and any success cases (94.8%±14.4%), with relatively short subintimal (3.6%±10.2% and 4.2%±11.2%, respectively) or intramedial (1.2%±5.8% and 1.0%±5.4%, respectively) crossing. CTO length was a significant risk factor for not achieving complete success (OR 1.74, 95% CI 1.13 to 2.68, p=0.012), and a history of failed revascularization was associated with not achieving any success (OR 6.40, 95% CI 1.28 to 28.9, p=0.038). Conclusion: The intraplaque route was the primary pathway taken by the TruePath reentry device as it crossed infrainguinal CTOs. Crossing rates were acceptable, with few device-related complications. However, a longer CTO length and a failed revascularization history negatively affected the success rate.

The role of precise imaging with intravascular ultrasound in coronary and peripheral interventions

Angiography remains a widely utilized imaging modality during vascular procedures. Angiography, however, has its limitations by underestimating the true vessel size, plaque morphology, presence of calcium and thrombus, plaque vulnerability, true lesion length, stent expansion and apposition, residual narrowing post intervention and the presence or absence of dissections. Intravascular ultrasound (IVUS) has emerged as an important adjunctive modality to angiography. IVUS offers precise imaging of the vessel size, plaque morphology and the presence of dissections and guides interventional procedures including stent sizing, assessing residual narrowing and stent apposition and expansion. IVUS-guided treatment has shown to yield superior outcomes when compared to angiography-only guided therapy. The cost-effectiveness of the routine use of IVUS during vascular procedures needs to be further studied.

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.

Lumen Gain After Endovascular Therapy in Calcified Superficial Femoral Artery Occlusive Disease Assessed by Intravascular Ultrasound (CODE Study)

Purpose: To assess calcium patterns in superficial femoral artery (SFA) disease before and after balloon angioplasty ± stent implantation using fluoroscopy, angiography, and intravascular ultrasound (IVUS) imaging and then correlate calcification severity and midterm clinical outcomes. Materials and Methods: A multicenter investigation was carried out to retrospectively review 130 symptomatic patients (mean age 73.2±8.4 years; 86 men) with de novo SFA lesions who had successfully undergone endovascular therapy (EVT) at 7 centers between January and October 2015. The primary outcome was lumen gain measured as minimum lumen area (MLA) in post-EVT IVUS images according to calcification severity. The secondary outcomes included rates of stent malapposition, restenosis, and clinically-driven target lesion revascularization (TLR). Results: A total of 102 (78.5%) cases had calcification in the lesions over a mean length of 64.3±72.8 mm. Of these, 70 cases were classified as having bilateral calcification according to fluoroscopy and angiography; 50 (49%) lesions had ≥180° calcification according to IVUS. The lumen gain in calcified lesions was significantly smaller than in the 28 noncalcified lesions (14.1±4.4 vs 17.8±5.2 mm2, p<0.001). IVUS-evaluated circumferential distribution of calcium (<180° or ≥180°) was independently associated with lumen gain after EVT (p<0.001). Among the calcification characteristics, a calcification angle ≥180° showed the strongest correlation to postprocedure MLA. Moreover, the restenosis rate was significantly higher in the severe (≥180°) calcification group (p<0.018). The severity of calcification was also associated with the risk of stent malapposition (p=0.022 for trend) but not TLR (p=0.57). Conclusion: IVUS evaluation of calcification in SFA lesions predicted lumen gain after EVT. Severe calcification in a ≥180° arc prevented successful dilation of the lesion with either plain balloon angioplasty or a nitinol stent. Accurate assessment of calcification patterns by IVUS is useful in maximizing the efficacy of endovascular therapy.

Accuracy of pre-interventional computed tomography angiography post-processing software and extravascularly calibrated devices to determine vessel diameters: comparison with an intravascularly located calibrated catheter

Background Accurate vessel sizing might affect treatment outcome of endovascular therapy. Purpose To compare accuracy of peripheral vessel diameter measurements using pre-interventional computed tomography angiography post processing software (CTA-PPS) and extravascularly located calibrated devices used during digital subtraction angiography (DSA) with an intravascular scaled catheter (SC). Material and Methods In 33 patients (28 men, mean age = 72 ± 11 years) a SC was used during DSA of the femoro-popliteal territory. Simultaneously, one scaled radiopaque tape (SRT) was affixed to the lateral thigh, one scaled radiopaque ruler (SRR) was positioned on the angiography table. For each patient, diameters of five anatomic landmarks were measured on DSA images after calibration using different scaled devices and CTA-PPS. Diameters were compared to SC (reference) and between groups of non-obese (NOB) and obese (OB) patients. Results In total, 660 measurements were performed. Compared to the reference, SRT overestimated the diameter by 1.2% (range = -10-12, standard deviation [SD] = 4.1%, intraclass correlation coefficient [ICC] = 0.992, 95% confidence interval [CI] = 0.989-0.992, P = 0.01), the SRR and CTA-PPS underestimated it by 21.3% (range = 1-47, SD = 9.4%, ICC = 0.864, 95% CI = 0.11-0.963, P = 0.08) and 3.2% (range = 17-38, SD = 9.7%, ICC = 0.976, 95% CI = 0.964-0.983, P = 0.01), respectively. Underestimation using the SRR was greatest in the proximal superficial-femoral artery (31%) and lowest at the P2 level of the popliteal artery (15%). In the NOB group, diameter overestimation of the SRT was 0.8% (range = 4-7, SD = 4.2%, B = 0.071, 95% CI = 0.293-0.435, P = 0.08) compared to the OB group of 1.6% (range = -7-4, SD = 2.9%, B = 0.010, 95% CI = 0.474-0.454, P = 0.96). Diameter underestimation of the SRR was 17.3% (range = 13-21, SD = 3.1%, B = 0.946, 95% CI = 0.486-1.405, P = 0.002) in the NOB group, 23.3% (range = 11-36, SD = 6.6%, B = 0.870, 95% CI = 0.268-1.472, P = 0.007) in the OB group. Conclusion For calibrated measurements SRT and CTA-PPS prove accurate compared to the reference, while SRR does not. Obesity has a significant impact on underestimation of diameter if SRR is used.

LumenRECON Guidewire: Pilot Study of a Novel, Nonimaging Technology for Accurate Vessel Sizing and Delivery of Therapy in Femoropopliteal Disease

BACKGROUND

Proper vessel sizing during endovascular interventions is crucial to avoid adverse procedural and clinical outcomes. LumenRECON (LR) is a novel, nonimaging, 0.035-inch wire-based technology that uses the physics-based principle of Ohm's law to provide a simple, real-time luminal size while also providing a platform for therapy delivery. This study evaluated the accuracy, reliability, and safety of the LR system in patients presenting for a femoropopliteal artery intervention.

METHODS AND RESULTS

This multicenter, prospective pilot study of 24 patients presenting for peripheral intervention compared LR measurements of femoropopliteal artery size to angiographic visual estimation, duplex ultrasound, quantitative angiography, and intravascular ultrasound. The primary effectiveness and safety end point was comparison against core laboratory adjudicated intravascular ultrasound values and major adverse events, respectively. Additional preclinical studies were also performed in vitro and in vivo in swine to determine the accuracy of the LR guidewire system. No intra- or postprocedure device-related adverse events occurred. A balloon or stent was successfully delivered in 12 patients (50%) over the LR wire. Differences in repeatability between successive LR measurements was 2.5±0.40% (R²=0.96) with no significant bias. Differences in measurements of LR to other modalities were 0.5±1.7%, 5.0±1.8%, -1.5±2.0%, and 6.8±3.4% for intravascular ultrasound core laboratory, quantitative angiography, angiographic, and duplex ultrasound, respectively.

CONCLUSIONS

This study demonstrates that through a physics-based principle, LR provides a real-time, safe, reproducible, and accurate vessel size of the femoropopliteal artery during intervention and can additionally serve as a conduit for therapy delivery over its wire-based platform.