Intravascular Ultrasound during Endovascular Intervention for Peripheral Artery Disease, by Severity, Location, Device, and Procedure

There is limited evidence for the role of intravascular ultrasound (IVUS) in patients who underwent peripheral vascular intervention (PVI). We conducted retrospective cohort study utilizing the Healthcare Cost and Utilization Project-Agency for Healthcare Research and Quality National Readmission database to delineate outcomes in IVUS-guided PVI versus non-IVUS-guided PVI. The present study utilized National Readmission database between January 1, 2016, and December 31, 2019. We identified patients who underwent endovascular intervention for peripheral artery disease using relevant International Classification of Diseases, Tenth Revision, Procedural Coding System. The cohort was divided based on the use of IVUS during the procedure. The primary outcome was major amputation at 6 months after index hospitalization. Measured confounders were matched using propensity score inverse probability of treatment weighing method. We further performed a subgroup analysis based on disease severity, location of intervention, device, and procedure. A total of 434,901 hospitalizations were included in the present analysis. PVI with IVUS compared with no IVUS had similar risk of amputation at 6 months (195 of 8,939 [2.17%] vs 10,404 of 384,003 [2.71%]), hazard ratio 0.98, CI 0.77 to 1.25. Further, there was no difference in the rates of secondary outcomes. On subgroup analysis, amputation rates were significantly lower in patients with rest pain, in iliac intervention, or patients who underwent drug-eluting stent implantation with the use of IVUS compared with no IVUS. This nationwide observational study showed that there was no difference in major amputation rates with the use of IVUS in patients who underwent PVI. However, in subgroup of patients with rest pain, iliac intervention or drug-eluting stent implantation IVUS use was associated with significantly lower major amputation rates.

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.

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.

Delayed rupture of peroneal artery pseudoaneurysm following endovascular treatment in a patient with chronic limb-threatening ischemia: A case report

Below-the-knee (BTK) pseudoaneurysms that occur after endovascular therapy (EVT) and result in delayed rupture have rarely been reported. In this report, we present a rare case of an 86-year-old man with chronic limb-threatening ischemia who developed delayed rupture of an idiopathic pseudoaneurysm of the peroneal artery (PA) following EVT. The PA chronic total occlusion (CTO) was successfully crossed using a guidewire via an antegrade approach, however, subintimal crossing was confirmed by intravascular ultrasound. Balloon angioplasty was then performed using an appropriately sized balloon, resulting in successful recanalization of the PA CTO with minor dissection and no complications. Postoperatively, the patient's condition was stable until he suddenly complained of right calf pain 10 days after EVT. Computed tomography revealed a rupture of the PA pseudoaneurysm. Urgent angiography revealed two pseudoaneurysms, one saccular and the other spindle-shaped. The ruptured saccular aneurysm was successfully excluded through coil embolization and stent graft placement. To the best of our knowledge, this is the first reported case of delayed rupture of a BTK pseudoaneurysm following EVT. Balloon angioplasty in the subintimal space can lead to the formation of a pseudoaneurysm and its delayed rupture.

Clinical feasibility of endovascular recanalization with intravascular ultrasound-guided wiring for chronic total occlusion of below-the-knee arteries

BACKGROUND

Revascularization with endovascular therapy (EVT) for complex below-the-knee (BTK) chronic total occlusion (CTO) remains a challenging problem. The Japanese-BTK (J-BTK) CTO score is reported as an indicator of the difficulty of BTK CTO, with the guidewire (GW) passage success rate decreasing as the grade increases. We previously reported an effective GW crossing method for the intravascular ultrasound (IVUS)-guided parallel wiring of complex BTK CTO. In this study, we investigated the feasibility of EVT using IVUS-guided wiring for BTK CTO.

MATERIALS AND METHODS

This single center, retrospective study analyzed 65 consecutive BTK CTO vessels in which IVUS-guided wiring was attempted after the failure of a conventional antegrade wiring approach from November 2020 to November 2022. The primary endpoint was the clinical success of the target CTO vessel. The secondary endpoints were the GW success rate per grade based on the J-BTK CTO score, number of GW used for CTO crossing, fluoroscopy time, and complications.

RESULTS

Target vessels were the anterior tibial artery (66.2% of cases), peroneal artery (9.2%), and posterior tibial artery (24.6%). Blunt type CTO entry was performed in 55.4% of cases, calcification of entry was observed in 24.6% of cases, the mean occlusion length was 228.2 ± 93.7 mm, mean reference vessel diameter was 2.1 ± 0.71 mm, and outflow was absent in 38.5% of cases. J-BTK CTO scores of 0/1 (grade A), 2/3 (grade B), 4/5 (grade C), and 6 (grade D) were seen in 18.5%, 43.1%, 36.3%, and 1.5% of cases, respectively. The clinical success rate was 95.4%. The GW success rate by J-BTK CTO grade was as follows: grade A (100%), B (100%), C (91.7%), and D (0%). The mean number of GW used was 3.4 ± 1.4, the mean fluoroscopy time was 72.3 ± 32.5 min, and complications occurred in 7.7% of cases.

CONCLUSION

This study showed a very high clinical success rate despite the difficulty of BTK CTO. IVUS-guided EVT might be a feasible strategy for complex BTK CTO.

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.

Successful Endovascular Therapy Using the Transtibial Approach in a Patient With a History of Iliofemoral and Femorofemoral Surgical Bypass

Multiple stenotic lesions may restrict the access sites for endovascular therapy in the lower extremity arteries. Because guide sheaths used for endovascular therapy have recently become easier to insert, they are directly inserted into the posterior tibial or dorsalis pedis artery to perform the transtibial approach. We herein describe an 81-year-old man who was admitted to our hospital because of claudication of the left lower extremity. He had a history of left iliofemoral and femorofemoral bypass surgery. The patient's symptom was due to a stenotic lesion extending from the left common femoral artery to the distal part of the left superficial femoral artery. In an angiographic procedure using the antegrade approach via the right radial artery, a multipurpose catheter became stuck in the middle of the left iliofemoral bypass. The antegrade ipsilateral approach was too close to the stenotic lesion for the insertion of the guide sheath. Therefore, a retrograde approach using a 5-French guide sheath inserted via the dorsalis pedis artery was successfully performed.

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.

Results of Excimer Laser Ablation Combined with Drug-Coated Balloon for Atherosclerotic Obliterans of Lower Extremity and Risk Factors for Loss of Primary Patency

BACKGROUND

The results of excimer laser ablation (ELA) combining with drug-coated balloon (DCB) in the treatment for atherosclerotic obliterans (ASO) remains unclear.

METHODS

Retrospectively enrolled patients who underwent ELA combined with DCB in 2 centers. The primary endpoint was primary patency, and secondary endpoints included technical success, procedure-related complications, major amputation, clinically driven target lesions reintervention (CD-TLR), measurements of ankle-brachial index (ABI), and quality of life (QoL).

RESULTS

102 patients were enrolled. The primary patency was 86.7% (95% confidence interval [CI]: 72.9%-89.0%) at 12 months and 82.6% (95% CI: 78.2%-92.1%) at 24 months. The freedom from reintervention was 87.8% (95% CI: 79.5%-92.9%) at 12 months and 86.6% (95% CI: 78.1%-92.0%) at 24 months. The ABI measurement and QoL were significantly improved at each follow-up point. Sixteen (15.7%) patients lost the primary patency. Patients losing the primary patency demonstrated higher Rutherford class (P = 0.004), worse runoff (P < 0.001), higher Peripheral Arterial Calcium Scoring System (PACSS) (P < 0.001), and smaller ratio of tube diameter to reference vessel diameter (TD/RVD) (P < 0.001) compared with patients without losing it. The run-off ≥7 (adjusted odds ratio [aOR]: 34.3; 95% CI: 2.9-398.3; P = 0.005) and TD/RVD <4.9 (aOR: 24.7; 95% CI: 1.7-359.5; P = 0.019) were independent risk factors for loss of primary patency.

CONCLUSIONS

ELA combined with DCB seemed an effective and safe treatment for ASO of lower extremity, and it could not only reduce the implantation of stent but significantly improve QoL. The run-off ≥7 and TD/RVD <4.9 were independent risk factors for loss of primary patency.

Two-year results of endovascular therapy for femoropopliteal artery disease in Japan during the introduction of drug-eluting devices

Although various devices and strategies were introduced into endovascular therapy, factors associated with chronic outcomes remain unclear. Therefore, this study aimed to build preliminary data of Japanese femoropopliteal lesions in a period of transition from non-drug to drug technology. This research was a multicenter, prospective, and observational study. A total of 1003 consecutive patients with a mean age of 73.6 ± 8.3 years from 67 institutes were registered from February 2017 to June 2018 in Japan. In addition to the baseline data, angiographic findings affecting primary patency were studied. Lesion length was 16.4 ± 9.6 cm, and chronic total occlusion was found in 42%. Calcified lesions were found in 75% of patients. The 1-year and 2-year freedom from target lesion revascularization were 81% and 75%, respectively, and maximum walking distance showed improvement over the two years (pre; 234 m ± 211 m, 1-year; 402 m ± 241 m, 2-year; 428 m ± 231 m). The independent predictors for primary patency were pre-procedure ankle-brachial index, history of minor amputation, ostium lesion, and drug-coated balloon use. Angiographic analysis revealed that only lesion length and full cover stent were related to primary patency. Two-year freedom from target vessel revascularization was 75% in the Japanese transitional period of drug-eluting devices. Maximum walking distance was improved and well maintained for up to 2-year.

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.

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 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).

An AnteOwl WR intravascular ultrasound-guided parallel wiring technique for chronic total occlusion of below-the-knee arteries

Background

Although endovascular therapy is used to treat chronic limb-threatening ischemia, long chronic total occlusion (CTO) is still challenging to treat. Especially in patients with poor run-off below-the-knee (BTK) arteries, it is difficult to perform a retrograde approach, and even guidewire passage may be difficult.

Case presentation

We treated two cases of chronic limb-threatening ischemia using our novel extreme antegrade guidewire crossing technique by AnteOwl WR intravascular ultrasound (IVUS)-guided parallel wiring to a BTK artery (EXCAVATOR technique). Case 1 was a 70-year-old man with ulceration of the right toe. The AnteOwl WR IVUS was intentionally advanced into the subintimal space of the posterior tibial artery, and the totally intraplaque route was advanced by IVUS-guided parallel wiring that was successfully passed from the lateral plantar aspect to the true lumen of the digital artery. Case 2 was a 76-year-old woman with rest pain and cyanosis of the right lower limb. Angiography showed total occlusion from the superficial femoral artery to BTK arteries. AnteOwl WR IVUS-guided parallel wiring was repeatedly performed until the distal true lumen of the peroneal artery was reached, and revascularization was successfully achieved via the antegrade approach alone.

Conclusions

With its excellent crossable performance, good image quality, and high navigational ability within the CTO, the AnteOwl WR can be used to pass parallel wiring into the distal true lumen for BTK CTO.

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.

Advances in Revascularization for Peripheral Artery Disease: Revascularization in PAD

Effective revascularization of the patient with peripheral artery disease is about more than the procedure. The approach to the patient with symptom-limiting intermittent claudication or limb-threatening ischemia begins with understanding the population at risk and variation in clinical presentation. The urgency of revascularization varies significantly by presentation; from patients with intermittent claudication who should undergo structured exercise rehabilitation before revascularization (if needed) to those with acute limb ischemia, a medical emergency, who require revascularization within hours. Recent years have seen the rapid development of new tools including wires, catheters, drug-eluting technology, specialized balloons, and biomimetic stents. Open surgical bypass remains an important option for those with advanced disease. The strategy and techniques employed vary by clinical presentation, lesion location, and lesion severity. There is limited level 1 evidence to guide practice, but factors that determine technical success and anatomic durability are largely understood and incorporated into decision-making. Following revascularization, medical therapy to reduce adverse limb outcomes and a surveillance plan should be put in place. There are many hurdles to overcome to improve the efficacy of lower extremity revascularization, such as restenosis, calcification, microvascular disease, silent embolization, and tools for perfusion assessment. This review highlights the current state of revascularization in peripheral artery disease with an eye toward technologies at the cusp, which may significantly impact current practice.

Prediction of successful guidewire crossing of below-the-knee chronic total occlusions using a Japanese scoring system

OBJECTIVE

To develop a scoring system that can adequately predict a successful guidewire crossing (S-GC) of below-the-knee (BTK) chronic total occlusions (CTOs) in angiographic evaluation.

METHODS

A retrospective, multicenter, nonrandomized study examined 448 consecutive BTK CTOs in 299 patients treated with endovascular therapy in seven Japanese medical centers from April 2012 to April 2020. The cohort was classified into two groups: an S-GC group and a failed guidewire crossing group.

RESULTS

The final logistic regression model created by a backward stepwise multivariate logistic regression model included five variables: "No outflow of the target vessel," "CTO length ≥200 mm," "Reference vessel diameter <2.0 mm," "Calcification at the proximal entry point," and "Blunt type at entry point." Optimisms were adjusted using 1000 bootstrap samples with replacement and candidate's risk score models developed according to optimism-adjusted correlation coefficients of risk factors. Choosing the best model as the Japanese-BTK (J-BTK) CTO score by comparing the optimism-adjusted area under receiver-operating characteristic curves it was decided to assign one point to "Blunt type at the proximal entry point," one point to "Calcification at the proximal entry point," one point to "Reference vessel diameter <2.0 mm," one point to "CTO length ≥200 mm," and two points to "No outflow of the target vessel." This rule was then used to categorize BTK CTOs into four grades with varying probabilities of S-GC: grade A (J-BTK CTO score of 0 and 1), grade B (score of 2 and 3), grade C (score of 4 and 5), and grade D (score of 6). Rates of S-GC in each grade (grades A, B, C, and D) were 97.3%, 76.8%, 19.3%, and 0%, respectively. Lesions categorized as grade C or D have a lower chance of S-GC. Internal validation was performed using the Hosmer-Lemeshow test (P = .99).

CONCLUSIONS

The J-BTK CTO score predicts the probability of an S-GC of BTK CTOs and stratifies the difficulty of endovascular therapy for BTK CTOs in angiographic evaluation.