Final Results of theChronic Total OcclusionCrossing With theOcelot System II (CONNECT II) Study

Midterm Results of Drug-Coated Balloon and Bare Metal Stent in the Treatment of TASCII C/D Femoropopliteal Artery Occlusive Disease: A Retrospective Multicenter Study

PURPOSE

This study aimed to compare midterm efficacy between drug-coated balloon (DCB) and bare metal stent (BMS) in the treatment of TASCII C/D femoropopliteal artery lesions.

METHODS

The clinical data of patients with TASCII C/D femoropopliteal artery disease admitted to 3 vascular surgery centers from January 2018 to January 2021 were retrospectively analyzed. Patients were divided into DCB group and BMS group. The DCB group was further subdivided into DCB alone subgroup and DCB+BMS subgroup. Study primary outcomes were freedom from clinical-driven target lesion reintervention (FCD-TLR) at 24 months postprocedure. Secondary outcomes included ankle brachial index (ABI), Rutherford classification, major amputation rate, and mortality.

RESULTS

A total of 410 consecutive patients were enrolled. At 24 months follow-up, in DCB group (114 patients) relative to BMS group (296 patients), FCD-TLR (86.00% vs 71.91%, p=0.039), and ABI (0.53±0.11 vs 0.47±0.19, p=0.007) were higher; mean Rutherford class was lower (1.57±0.68 vs 3.31±1.39, p=0.000); and major amputation rate (0.87% vs 4.05%, p>0.05) and all-cause mortality (8.92% vs 6.41%, p>0.05) were statistically similar. In DCB alone, subgroup relative to DCB+BMS subgroup, FCD-TLR (90.00% vs 85.00%, p>0.05), major amputation rate (0 vs 1.08%, p>0.05), and all-cause mortality rate (9.09% vs 8.69%, p>0.05) were statistically similar, while FCD-TLR was higher in the DCB+BMS subgroup (90.00% vs 71.91%, p=0.045).

CONCLUSION

At midterm follow-up of patients treated for TASCII C/D femoropopliteal artery disease, use of DCB or of DCB combined with rescue BMS appeared similarly efficacious, and yielded more favorable outcomes than use of BMS.

CLINICAL IMPACT

The efficacy of drug-coated balloons relative to that of bare metal stents for the treatment of complex femoropopliteal artery lesions, particularly TASCII grade D lesions, remains uncertain. There is a scarcity of multicenter comparative studies, and in this multicenter retrospective study with up to 24-month follow-up, use of drug-coated balloon alone or combined with rescue bare metal stent appeared similarly efficacious while yielding more favorable outcomes than use of bare metal stent alone in the treatment of TASCII grade C/D femoropopliteal artery lesions. Randomized studies are warranted.

First Experience With The GoBack-Catheter For Successful Crossing of Complex Chronic Total Occlusions in Lower Limb Arteries

PURPOSE

To evaluate the use of the GoBack-catheter (Upstream Peripheral Technologies) in complex revascularizations in lower limb arteries.

MATERIALS AND METHODS

In this retrospective single-center study, the results of the first 100 consecutive patients including 101 limb-revascularizations, performed between May 2018 and July 2020 with the study device, were analyzed. In all cases, guidewire-crossing failed, and all lesions were chronic total occlusions (CTO), either de novo, reocclusions, or in-stent reocclusions. Successful crossing was defined as passing the CTO using the study device. Patency at discharge and after 30 days was defined as less than 50% restenosis on duplex sonography, without target lesion revascularization.

RESULTS

Median lesion length was 24 cm and 38 patients (37.6%) had a calcium grading according to the peripheral arterial calcium scoring system (PACSS) of 4 or 5. In 20.8% of patients, an occluded stent was treated. CTOs involved the femoropopliteal segment in 91.1%, iliac arteries in 5.9%, and tibial arteries in 7.9%. The GoBack-catheter was employed for entering into or crossing through parts or the full length of a CTO or an occluded stent as well as for re-entering into the true lumen after subintimal crossing. The device was used via contralateral and ipsilateral antegrade as well as retrograde access with an overall technical success rate of 92.1%. In 3 patients minor bleeding occurred at the crossing or re-entry site, which were managed conservatively. Thirty-day adverse limb events comprised minor amputations in 4 patients (4.0%), 1 major amputation (1.0%), and reocclusions in 7 limbs (6.9%).

CONCLUSION

The new GoBack-catheter offers versatile endovascular applicability for complex CTO recanalization in a broad range of peripheral vascular interventions with a high technical success and low complication rate.

A Multinational, Single-Arm Pivotal Study Assessing the Performance of the SoundBite Crossing System for Peripheral Chronic Total Occlusions (The PROSPECTOR Study)

PURPOSE

This study aimed to demonstrate the efficacy and safety of the SoundBite Crossing System‒Peripheral (SCS-P) to facilitate crossing chronic total occlusions (CTOs) of infrainguinal arteries.

MATERIALS AND METHODS

This clinical trial was approved by the Ethics Committees of all 4 participating centers and enrolled 52 patients with symptomatic de novo infrainguinal CTOs. Technical device success, the primary efficacy endpoint, was defined as the ability to facilitate the treatment of the target lesion by crossing a portion or the whole length of the CTO. Freedom from SCS-P-related major adverse events (MAEs) at 30 days after the procedure was the primary safety endpoint.

RESULTS

The SCS-P met the primary efficacy and safety endpoints in 92.3% (48/52) and 100% (52/52) of subjects, respectively. Technical device success with postprocedural patency and freedom from SCS-P-related MAEs was achieved in 88.5% (46/52) of subjects. The mean CTO crossing time was 20.0 minutes ± 30.8, and the SCS-P was able to traverse the whole CTO and enter the distal true lumen without the need of any other device in 59.6% (31/52) of subjects. The mean Rutherford category and ankle-brachial index improvement at the 30-day follow-up was 2.4 ± 1.17 and 0.23 ± 0.22, respectively.

CONCLUSIONS

The SCS-P demonstrated a satisfactory safety and performance profile to cross peripheral CTOs and enter the distal true lumen of infrainguinal CTOs.

Optical coherence tomography in peripheral arterial disease: A systematic review

BACKGROUND

Optical coherence tomography (OCT) is a novel adjunct in the field of medicine. The objective of this systematic review was to evaluate the role of OCT in the field of contemporary endovascular surgery in terms of its utility in diagnostics and interventions in peripheral arterial disease (PAD).

METHOD

A systematic search of literature published from 1st January 2009 to 1st August 2019 was identified from PubMed, Ovid and Cochrane library database with reference to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The pre-defined selection inclusion criteria were clinical applications of OCT in vascular surgery in relation to diagnostics and interventions. Keywords used included OCT, PAD, endovascular procedures and atherectomy.

RESULTS

From an initial search of 310 articles, 27 articles were included in this systematic review: 15 articles were related to diagnostics: peripheral arterial disease was the most studied condition (n = 8), other conditions included in-stent restenosis (n = 4), fibromuscular dysplasia (n = 2) and acute limb ischaemia (n = 1); 12 articles were related to intervention: an OCT-guided crossing catheter was the most used assisting device (n = 10), with an OCT-guided atherectomy device used in four of these studies.

CONCLUSION

Although there is currently no level 1 evidence to suggest routine use of OCT in the diagnosis and treatment of PAD, current literature suggests that the use of OCT is safe and effective. The OCT real-time vessel wall structural images clearly distinguish normal anatomy from plaque pathology, and are of great advantage both in the accurate diagnosis and treatment of target lesion, especially in reducing the amount of radiation in the endovascular procedure.

Clinical considerations after endovascular therapy of peripheral artery disease

Introduction: Patients with peripheral artery disease (PAD) are at higher risk for all-cause mortality, driven by increased cardiovascular mortality rates. In this manuscript we review the literature on guideline-recommended therapies and discuss the major clinical considerations after endovascular therapy of PAD.Areas covered: Current guidelines recommend smoking cessation, aspirin, statin, and renin-angiotensin system inhibitors in order to reduce the risk of cardiovascular and limb-related adverse events. Nonetheless, studies have shown that patients with PAD are undertreated with these important medical therapies. Additionally, there is lack in evidence regarding the most optimal follow up imaging approach for early detection of disease recurrence and re-intervention among patients undergoing endovascular therapy for PAD. We also describe the benefits of supervised walking exercise for patients with PAD that undergo revascularization procedures and are fit for such interventions.Expert opinion: Adherence to guideline recommended medical therapy is crucial for improved outcomes in PAD management. Systematic assessment of risk-reduction interventions could help increase adherence to clinically beneficial interventions and improve the overall prognosis of patients with PAD undergoing revascularization procedures. Additionally, optimization of current follow up protocols is needed, with the optimal goal to develop standardized cost-effective algorithms regarding early detection of disease recurrence and re-intervention.

Safety and outcomes of combined carbon dioxide angiography and OCT-guided femoro-popliteal chronic total occlusion crossing and directional atherectomy in patients with chronic kidney disease

BACKGROUND

Carbon dioxide angiography with addition of optical coherence tomography imaging may improve procedural success and clinical outcomes in patients with peripheral artery disease and chronic kidney disease.

METHODS

Single-center, retrospective analysis of patients with chronic kidney disease who underwent carbon dioxide angiography and optical coherence tomography-guided chronic total occlusion crossing and/or optical coherence tomography-guided directional atherectomy was performed. Patient and procedure-related characteristics, along with peri- and one-year post-procedural major adverse events, were analyzed.

RESULTS

A total of 18 vessels in 11 patients, with mean age 70 years were treated. All had co-morbidities such as hypertension, hyperlipidemia, had history or were current smokers with baseline peripheral artery disease. Majority were diabetic with coronary disease (82%); 55% baseline chronic kidney disease IV, 55% Rutherford class III and 45% class IV. Contrast was used in only two patients. Mean total fluoroscopy time and radiation dose was 24.1 min and 249.2 mGY, respectively. Half of the lesions were femoro-popliteal chronic total occlusions, and Ocelot catheter was used to cross seven of nine chronic total occlusions and was successful in six. Adjunctive optical coherence tomography-guided directional atherectomy was performed in 8 of 11 patients. Only two adverse events occurred: one clinically significant event of slow-flow intra-procedurally and one target limb revascularization within one year of index procedure in a vessel different than prior treated. Optical coherence tomography imaging in both chronic total occlusion-crossing and atherectomy resulted in 10-min mean fluoroscopy reduction time and 32 mGY reduction in radiation dose.

CONCLUSION

Carbon dioxide angiography with the addition of optical coherence tomography imaging for chronic total occlusion crossing and/or optical coherence tomography-guided directional atherectomy reduced the need for contrast agents, total fluoroscopy time, and radiation exposure in patients with peripheral artery disease and baseline chronic kidney disease.

Safety and efficacy outcomes of the Pioneer Plus catheter in endovascular revascularization of lower extremity chronic total occlusions

OBJECTIVE

Our aim was to evaluate the efficacy and safety outcomes of the Pioneer Plus catheter (Philips, San Diego, Calif) and report the in-hospital and 30-day outcomes of lower extremity chronic total occlusion (CTO) interventions assisted by the Pioneer Plus catheter. In addition, we explored the factors associated with procedural success.

METHODS

We conducted a retrospective review of 135 consecutive procedures in 116 patients from July 2011 to September 2018 performed by eight operators with various levels of experience at a high-volume center where the Pioneer Plus catheter was used for lower extremity CTO. The patient demographics, preprocedural symptoms, preprocedural testing results, procedural setting, and angiography findings were abstracted. The outcomes were divided into device-related and procedure-related outcomes. Device-related efficacy outcome included procedural success. Device-related safety outcomes included device-related complications. Procedure-related outcomes included procedure-related complications, 30-day major adverse cardiovascular events, and 30-day major adverse limb events. We conducted univariate comparisons of the provider, patient, and procedural characteristics stratified by procedural success.

RESULTS

Procedural success was observed in 118 procedures overall (87.4%), and success rates ≤95.8% were observed for operators with an experience level of >25 devices deployed. No device-related complications, such as pseudoaneurysm formation, vessel perforation, or arteriovenous fistula formation, were observed. The Pioneer Plus catheter was mostly often used for CTO in the superficial femoral and popliteal arteries. Overall, the procedure-related complications included access site hematoma (5.2%), major bleeding (0.7%), pseudoaneurysm formation (0.7%), distal embolization (1.5%), and acute arterial thrombosis (1.5%). The 30-day major adverse limb events included index limb unplanned amputation (0.7%), index limb reintervention (4.4%), and index limb acute limb ischemia (0.7%) and occurred in 5.9% of the procedures. The only factor associated with procedural success was operator experience (P < .0001).

CONCLUSIONS

The results from the present study have shown that Pioneer Plus catheter use is safe and effective when used to cross lower extremity CTO. However, further investigation is needed to identify patient- and provider-level factors to optimize patient outcomes.

Optical coherence tomography and plaque morphology for revascularization of the superficial femoral artery

Background

The optical coherence tomography (OCT) catheter, Ocelot (Avinger Inc., Redwood City, CA), has been utilized to cross Trans-Atlantic Inter-Society Consensus Document (TASC) D lesions. Studies have assessed the characteristics of high-risk plaques in the carotid artery, but few, if any data exist evaluating OCT and plaque morphology in the superficial femoral artery (SFA). This study assessed SFA plaque morphology using OCT and lesion crossing success in chronic total occlusions (CTOs).

Methods

We reviewed patients who underwent attempted infrainguinal revascularization with TASC D CTOs using the Ocelot catheter between June 2014 and June 2018, and recorded demographic information, smoking status, and medical comorbidities. A matched cohort of 44 successfully crossed lesions was compared to 44 that failed; images insufficient for analysis were excluded. The morphology of the plaque was studied using OCT at the proximal cap, midpoint of the lesion, and the distal cap. Morphologic data studied included the intima-media thickness ratio, cross-sectional area of the plaque, and gray-scale median of the plaque.

Results

A total of 140 patients who underwent lower extremity procedures for TASC D lesions of the SFA with OCT imaging were reviewed with a crossing rate of 69.0%. No significant differences were found between crossed and uncrossed lesions for intima-media thickness or cross-sectional area at the proximal cap, the midpoint, or the distal cap. A lower gray-scale median at the proximal cap was associated with the ability to cross the chronic SFA occlusion (P=0.05). Subgroup analysis stratified by smoking and calcium content also demonstrated that a lower gray-scale median at the proximal cap was associated with the ability to cross the chronic SFA occlusion (P=0.01 and P=0.04, respectively).

Conclusions

Lower gray-scale median at the proximal cap of a chronic SFA occlusion calculated using OCT images was associated with the ability to successfully cross the lesion. Higher plaque gray-scale median is correlated with increased calcium, greater fibrous tissue, and signal-rich plaques. Gray-scale median in the proximal cap is useful marker to determine plaque composition and subsequent technical success for crossing chronic SFA occlusions. Further studies are needed to fully determine the utility of OCT images to predict successful endovascular revascularization of chronic SFA occlusions.

Endovascular Intervention for the Treatment of Trans-Atlantic Inter-Society Consensus (TASC) D Femoropopliteal Lesions: A Systematic Review and Meta-Analysis

PURPOSE

Advancements in the endovascular treatment of femoropopliteal atherosclerotic lesions have led to treatment of more complex lesions, particularly long lesions. The aim of this study was to determine the meta-analytic primary patency and need for re-intervention among patients treated for very long lesions (>200 mm) at the femoropopliteal segment and to identify potential risk factors for loss of patency.

METHODS

This study was performed according to the PRISMA guidelines. A random effects model meta-analysis was conducted, and the I-square was used to assess heterogeneity.

RESULTS

Fifty-one studies comprised of 3029 patients were included. The mean lesion length was 269 mm. The primary patency rate at 30 days, 6 m, 1-, 2- and 5-years of follow-up was 98%, 76%, 62%, 55%, and 39% respectively. The incidence of TLR was 16% at one year and 32% at two years. The secondary patency rate at 1, 2, 3 and 5 years was 85%, 71%, 64%, and 64% respectively. Heparin bonded ePTFE covered stents (69%) and paclitaxel eluting stents (73%) demonstrated higher 1-year primary patency rates than self-expanding nitinol stents (55%) or uncoated percutaneous transluminal angioplasty (PTA) with provisional stenting (54%). Lesions treated with a heparin bonded ePTFE covered stent had statistically significant higher odds of remaining patent at 1-year of follow-up (OR: 2.74; 95%CI: 1.63-4.61; p < 0.001) than lesions treated with BMS or PTA. Patients with long femoropopliteal lesions causing critical limb ischemia (CLI) developed restenosis or occlusion more often than patients treated for claudication (HR: 1.63; 95%CI: 1.06-2.49; p = 0.026) during an average follow-up of 26 months.

CONCLUSION

Primary stenting of femoropopliteal TASC D lesions using drug eluting stents or covered stents results in sustained patency over time. PTA or uncoated nitinol stents demonstrated lower patency rates. However, additional comparative studies are needed to determine the efficacy of newer technologies for the treatment of complex femoropopliteal lesions and provide evidence for the most optimal treatment approach.

A post-market, multi-vessel evaluation of the imaging of peripheral arteries for diagnostic purposeS comparing optical Coherence tomogrApy and iNtravascular ultrasound imaging (SCAN)

Background

Intravascular imaging plays an important part in diagnosis of vascular conditions and providing insight for treatment strategy. Two main imaging modalities are intravascular ultrasound (IVUS) and optical coherence tomography (OCT). The objective of this study was to prove non-inferiority of OCT imaging to IVUS images in matched segments of peripheral vessels in patients with suspected peripheral vascular disease.

Methods

The SCAN study was a prospective, non-inferiority clinical study of matched IVUS and OCT images collected along defined segments of peripheral vessels from twelve subjects (mean age 68 ± 10.3 years; 10 men) displaying symptoms of vascular disease. Luminal diameters were measured by both imaging systems at the distal, middle, and proximal points of the defined segments. Three blinded interventional radiologists evaluated the quality of both imaging modalities in identifying layered structures (3-point grading), plaque (5-point grading), calcification (5-point grading), stent structure (3-point grading), and artifacts (3-point grading) from 240 randomly ordered images. Mean grading scores and luminal diameters were calculated and analyzed with Student’s t-Test and Mann-Whitney-Wilcoxon testing. Intrareader reproducibility was calculated by intraclass correlation (ICC) analysis.

Results

The mean scoring of plaque, calcification, and vascular stent struts by the three readers was significant better in terms of image quality for OCT than IVUS (p < 0.001, p = 0.001, p = 0.004, respectively). The mean scores of vessel wall component visibility and artifacts generated by the two imaging systems were not significantly different (p = 0.19, p = 0.07, respectively). Mean vessel luminal diameter and area at three specific locations within the vessels were not significantly different between the two imaging modalities. No patient injury, adverse effect or device malfunction were noted during the study.

Conclusions

Imaging by OCT provides the physician with better visualization of some vessel and plaque chacteristics, but both IVUS and OCT imaging are safe and effective methods of examining peripheral vessels in order to perform diagnostic assessment of peripheral vessels and provide information necessary for the treatment strategy of peripheral artery disease.

Trial registration

NCT03480685 registered on 29 March 2018.

Five-year outcomes after revascularization of superficial femoral artery occlusion using Ocelot catheter

Introduction

The population of patients with lower limb atherosclerosis includes a considerable proportion of individuals with long superficial femoral artery (SFA) lesions. Chronic total occlusions (CTOs) represent the "last frontier" of percutaneous interventions. While open strategies are considered earlier as standard management for these lesions, the results of a number of trials indicate that endovascular management might become an effective alternative to surgery.

Material and methods

This paper presents 5-year outcomes of a first-in-man (FIM) study (before CE mark) and the registry of OCT Guided Ocelot Catheter (Avinger) for chronic total occlusions of the superficial femoral artery. The study group comprised 10 patients with Rutherford 3 lower limb ischemia including nine men and one woman.

Results

The efficacy of the primary intervention was 90%. Angiography performed at 6 months of the procedure, according to the study protocol, revealed 3 and 1 cases of restenosis and reocclusion, respectively, repaired using PTA and open common and deep femoral artery patch plasty. Doppler ultrasound performed at 1, 2 and 5 years after the primary intervention did not reveal significant target vessel restenosis. The primary and primary-assisted patency was 89%. During a 5-year follow-up, four peripheral percutaneous interventions and one femoropopliteal bypass surgery were performed in non-target limbs. There were no cardiovascular deaths, myocardial infarction or stroke and no amputation was required.

Conclusions

This is a first-in-man study reporting long-term follow-up after SFA CTO revascularization using the Ocelot catheter. The catheter proved to have a satisfactory safety profile and a high proportion of CTO crossings. A 5-year follow-up revealed high primary and primary-assisted patency rates.

Primary Use of the TruePath Crossing Device for Infrainguinal Chronic Total Occlusions With Intravascular Ultrasound Evaluation

PURPOSE

To evaluate the use of the TruePath crossing device as the primary recanalization tool for infrainguinal chronic total occlusions (CTO).

METHODS

A retrospective analysis was conducted of 50 patients (mean age 75 years; 26 men) with 55 infrainguinal CTOs treated with the TruePath between March 2017 and September 2017 at a single center. The mean occlusion length was 138±55 mm, and femoropopliteal lesions accounted for 65% of the 55 lesions. The primary outcome measure was CTO crossing using the TruePath alone; secondary outcomes were assisted success (>50% lumen gain using the TruePath), device-related complications, and intraluminal crossing evaluated by intravascular ultrasound (IVUS).

RESULTS

Complete success was achieved in 33 (60%) of 55 lesions having a mean occlusion length of 145±72 mm. Among these, the true lumen crossing rate was 97% according to IVUS evaluation. Assisted success was achieved in 15 (68%) of the 22 failures. Complete/assisted success, in which the TruePath was thought to have contributed to CTO crossing, was attained in 48 (87%) of the 55 lesions. Three (5.5%) complications were observed: a perforation, an access-site hematoma, and acute occlusion; only the perforation was device related (1.8%). Multivariate analysis showed PACCS grade 4 (odds ratio 4.5, 95% confidence interval 1.33 to 15.5, p=0.02) was an independent predictor of TruePath failure.

CONCLUSION

Primary use of the TruePath crossing device for infrainguinal CTOs demonstrated a satisfactory complete success rate and a high rate of IVUS-documented intraluminal crossing with few device-related complications. Severe calcification is an independent predictor of TruePath failure.

Use of the Ocelot catheter in iliac chronic total occlusion intervention

PURPOSE

The optical-coherence tomography guided Ocelot catheter has previously been shown to be a safe and effective tool for crossing peripheral chronic total occlusions. However, the existing literature focuses mostly on the superficial femoral artery, without prior evidence of use within the suprainguinal vasculature.

CASE SERIES

We present the first known cases of the Ocelot catheter for revascularization of chronic total occlusions in the iliac vasculature. In the first case a retrograde approach is used for intervention of the right common iliac artery, while in the second case an antegrade approach is used for revascularization of the left external iliac artery.

CONCLUSIONS

In this case report we first demonstrate as proof of feasibility the use of the Ocelot catheter in suprainguinal artery chronic total occlusions.

Preoperative assessment of computerized tomography angiography to predict success for crossing long Trans-Atlantic Inter-Society Consensus D lesions using the optical coherence tomography catheter

Objectives Optical coherence tomography chronic total occlusion catheter, the Ocelot (Avinger Inc., Redwood City, CA), has been utilized to cross Trans-Atlantic Inter-Society Consensus D lesions. This study evaluated the preoperative computerized tomography angiography of chronic total occlusions in the superficial femoral artery to predict clinical success. Methods We reviewed all patients who underwent lower extremity procedures with the Ocelot catheter from June 2014 to August 2016. Patients who had a preoperative computerized tomography angiography were evaluated. Final outcomes, plaque morphology, lesion length, calcium surface area, lesion location, and patient characteristics were analyzed. Results A total of 107 patients underwent lower extremity interventions with the Ocelot catheter. Seventy patients had a preoperative computerized tomography angiography scan prior to lower extremity intervention and 77% (54) had Trans-Atlantic Inter-Society Consensus D lesions that were crossed. Mean age was 62.8 years and 68.6% were male. Mean chronic total occlusion length was 182.7 mm (170.8 mm crossed vs. 222.6 mm uncrossed, p = 0.03). Calcium distribution differed significantly ( p<.01): circumferential (14.8 vs. 12.5%); eccentric (85 vs. 62.5%); and complete calcium occlusion (0 vs. 25%) for lesions that were crossed and uncrossed, respectively. Significant differences ( p<.0001) were found when calcium occlusion was less than 50% (87 vs. 31%), 51-75% (9.3 vs. 31.2%), and 76-100% (3.7 vs. 37.5%). Total calcium length in crossed lesion was 51.6 mm, and 92.8 mm in uncrossed lesions ( p = 0.10). No significant differences were noted for patient gender, occlusion location (proximal, middle, and distal superficial femoral artery), and kidney function. Conclusion The Ocelot catheter is an effective method to cross long Trans-Atlantic Inter-Society Consensus D lesions. Superficial femoral artery lesions longer than 17 cm and focal plaque morphology, specifically a total cross-sectional area of calcium and a calcium surface area greater than 50% were most predictive of failure to cross Trans-Atlantic Inter-Society Consensus D superficial femoral artery lesions. Computerized tomography angiography is an effective tool to predict success for crossing chronic total occlusions using optical coherence tomography technology and a critical consideration for patient selection.

Outcome After Crossing Femoropopliteal Chronic Total Occlusions Based on Optical Coherence Tomography Guidance

AIMS

The crossing of chronic total occlusions (CTOs) is the key step for an endovascular treatment. The Ocelot system is a novel device that combines a steerable drilling tip with optical coherence tomography (OCT) technology. It provides intraluminal imaging to help the crossing of CTOs in the femoropopliteal segment. Aim of the study was to determine early and midterm results after recanalization with this device.

METHODS AND RESULTS

During a period of 16 months, 84 CTOs were treated using the Ocelot system and prospectively registered. The primary end points were technical success and the primary and secondary patency of the lesion. Risk factors associated with early and midterm results were also analyzed. In all, 58 (69.0%) lesions were treated for intermittent claudication, 26 (31.0%) for critical limb ischemia, 34 (40.5%) were classified as Trans-Atlantic Inter-Society Consensus II D lesions, and 22 (26.2%) showed severe calcifications. The technical success rate was 72.6%. During 36 months of follow-up (mean 25.9), there were 10 reinterventions. The primary and secondary patency at 36 months were 54.2% and 68.1%, respectively.

CONCLUSIONS

In our experience, the Ocelot system would appear to be a safe and effective tool for increasing the applicability of endovascular techniques. However, the midterm results did not show drastic improvement.

Endovascular Devices and Revascularization Techniques for Limb-Threatening Ischemia in Individuals With Diabetes

Diabetes mellitus (DM) is a rapidly worsening global epidemic over the last thirty-five years. The increased prevalence of DM has changed the phenotypic expression of atherosclerotic limb threatening ischemia (LTI), resulting in an increase in lesions in the tibial vessels. These patients are also afflicted with peripheral neuropathy, foot deformities, and medial calcification of the vasculature. In response to the evolving phenotype of atherosclerosis, newer minimally invasive tools and techniques have been developed to improve the blood supply in LTI. Arterial access, traditionally obtained from the contralateral common femoral artery (CFA) in a retrograde fashion, is now also frequently being obtained in the ipsilateral limb in an antegrade fashion. Retrograde access of the tibial, pedal, tarsal, or calf collateral vessels is also being utilized to provide a route through which wires, catheters, balloons and stents may be placed. Wires have evolved to have a variety of diameters, materials and coatings providing interventionalists with a wide variety of choices when attempting to traverse blockages in the arteries. When catheters and wires fail to traverse the lesion, newer chronic total occlusion (CTO) devices have been developed to aid in the placement of a wire across the offending lesions. Due to medial calcification associated with DM, atherectomy devices have been developed to debulk the atherosclerotic plaque within the vessel. High pressure balloon angioplasty with or without stents remain the mainstay of intervention, with drug-coated balloons (DCBs) and drug-eluting stents (DESs) now being frequently used to prevent reocclusions of atherosclerotic lesions.

Percutaneous Therapies for Peripheral Artery Disease

Percutaneous therapies for peripheral artery disease continue to evolve with new techniques and devices. Although guidelines-recommended therapies have impacted cardiovascular morbidity and mortality, endovascular interventions have been shown to reduce limb pain, improve quality of life, and prolong walking distance for those with claudication and to reduce amputation rates among those with critical limb ischemia. Novel devices such as drug-eluting stents and drug-coated balloons have improved patency for moderate-length lesions, whereas others allow treatment of heavily calcified and tortuous segments. New adjunctive devices to cross lesions and reduce or modify associated plaque have also been developed, although level 1 data regarding their efficacy are sparse. There has also been a better mechanistic understanding of lower extremity endovascular treatment using tools such as intravascular ultrasound. This information has highlighted the need for better stent size selection for the femoropopliteal arterial segments and larger balloon diameters for the tibial arteries. Moreover, a wound perfusion approach with direct in-line flow, the so-called angiosome approach, and reconstruction of the pedal loop have been advocated for improved wound healing. Technical advances such as the tibiopedal access and reentry methods have allowed crossing of lesions that were considered no option for the endovascular approach in the past. Collectively, there has been increased awareness, interest, and commitment by various specialty societies and organizations to advance the treatment of peripheral artery disease and critical limb ischemia. This is also evident by the recent coalition of 7 professional societies and organizations that represented >150 000 allied health professionals and millions of patients with peripheral artery disease at the 2015 Centers for Medicaid and Medicare Services Medicare Evidence Development and Coverage Analysis Committee meeting. The percutaneous therapies for peripheral artery disease continue to evolve with longer follow-up with randomized data and larger prospective registries. In the future, it is hopeful that we will treat the lower extremity arteries according to segments, taking into account plaque morphology, luminal versus subintimal crossing, location, and stenotic versus occlusive disease. Until then, we must identify the most cost-effective, efficacious, and safe treatment for each patient. The goal of this article is to aid the practicing vascular specialist consider the optimal choices for the management of patients with vascular disease.

Endoscopic optical coherence tomography: technologies and clinical applications [Invited]

In this paper, we review the current state of technology development and clinical applications of endoscopic optical coherence tomography (OCT). Key design and engineering considerations are discussed for most OCT endoscopes, including side-viewing and forward-viewing probes, along with different scanning mechanisms (proximal-scanning versus distal-scanning). Multi-modal endoscopes that integrate OCT with other imaging modalities are also discussed. The review of clinical applications of endoscopic OCT focuses heavily on diagnosis of diseases and guidance of interventions. Representative applications in several organ systems are presented, such as in the cardiovascular, digestive, respiratory, and reproductive systems. A brief outlook of the field of endoscopic OCT is also discussed.

Recanalization of peripheral chronic total occlusions: 'no fancy devices, just a crossing catheter'

BACKGROUND

Chronic total occlusions (CTOs) are challenging to treat endovascularly. Classic subintimal approach is offering only moderate success rates mainly due of the lack of dedicated crossing catheters. Purpose of this study is to assess the acute procedural success of the use of a novel hydrophilic crossing catheter in the recanalization of peripheral CTOs.

MATERIALS AND METHODS

This is a retrospective, single-centre study of patients with femoropopliteal CTOs. Revascularization was performed with the use of the NaviCross®- crossing catheter (Terumo Europe). Technical, procedural success and complications were assessed.

RESULTS

Thirty-two patients were included in the study. Mean age was 65.9 (46-85) years; Critical limb ischemia was the indication for the procedure in 26 (81%). Target vessels included 12 superficial femoral arteries, 9 popliteal, and 11 femoropopliteal segment lesions. Mean length was 85 (50-350) mm; 21(65.6%) lesions were heavily calcified. In all cases a sub-intimal approach was used; in 21 cases the procedure was performed as a day case. Technical success was achieved in 31 (96.8%) cases. Recanalization was achieved with a guidewire in 22 (71%) lesions and with the catheter alone in 9 (29%) cases. Procedural success was achieved in all lesions. No major adverse events occurred.

CONCLUSION

The use of the NaviCross®- crossing catheter showed high rate of technical and procedural success in challenging femoropopliteal CTOs without significant complications. The use of this catheter needs to be considered as the first approach for CTOs prior to the use of any other more complex re-entry device.

Novel CenterCross and MultiCross devices for the treatment of infrainguinal chronic total occlusions: initial single-centre experience

AIMS

Our aim was to evaluate the effectiveness and safety of CenterCross/MultiCross devices to facilitate the crossing of chronic total occlusions in peripheral arteries.

METHODS AND RESULTS

This was a single-centre study in which 53 consecutive patients who were not amenable to initial attempts at crossing using standard guidewires underwent an attempt to recanalise chronically occluded infrainguinal peripheral arteries with MultiCross/CenterCross devices. The primary endpoint of interest was the ability to advance the guidewire beyond the chronic total occlusion (CTO) lesions with the use of these devices. Safety endpoints were freedom from bleeding, distal embolisation and vessel perforation, dissection or need for emergent surgical intervention. Popliteal artery and below lesions were the most commonly treated, comprising 89% of the total. The CTO lesions were crossed successfully in 92.4% of the cases within a relatively short time (5.5±3.5 minutes). There was no bleeding, dissection or need for emergent surgery and 98.1% and 96.2% of the patients were free from distal embolisation and perforations, respectively.

CONCLUSIONS

Our study demonstrated that MultiCross and CenterCross were effective and safe for recanalisation of peripheral CTO lesions which were not amenable to conventional guidewires. Further study is required to define the role of these novel devices in the treatment of complex lesions, particularly CTOs in patients with peripheral arterial disease.

Treatment of Chronic Total Occlusions Using the Avinger Ocelot Crossing Catheter

Peripheral arterial disease is becoming more prevalent as the population ages. In addition, the severity of the disease seems to be progressing from simple narrowing of vessels to chronic total occlusions (CTOs). Treatment of CTOs of the infrainguinal peripheral arteries remains a challenge even for experienced endovascular specialists. Many crossing techniques have been described ranging from standard guidewire and catheter-based techniques including subintimal recanalization to specialized CTO crossing devices. One of the newest technologies, the Avinger Ocelot catheter (Avinger, Inc., Redwood City, CA), employs optical coherence tomography imaging on the tip of a rotating crossing catheter to allow visual confirmation of luminal passage. This article will review this new technology for crossing CTOs, review the results of the multicenter CONNECT II trial, and discuss the potential benefits of direct visualization while crossing occlusions.

Diagnostic imaging capabilities of the Ocelot -Optical Coherence Tomography System, ex-vivo evaluation and clinical relevance

BACKGROUND

Optical coherence tomography (OCT) is a high-resolution sub-surface imaging modality using near-infrared light to provide accurate and high contrast intra-vascular images. This enables accurate assessment of diseased arteries before and after intravascular intervention. This study was designed to corroborate diagnostic imaging equivalence between the Ocelot and the Dragonfly OCT systems with regards to the intravascular features that are most important in clinical management of patients with atherosclerotic vascular disease. These intravascular features were then corroborated in vivo during treatment of peripheral arterial disease (PAD) pathology using the Ocelot catheter.

METHODS

In order to compare the diagnostic information obtained by Ocelot (Avinger Inc., Redwood City, CA) and Dragonfly (St. Jude Medical, Minneapolis, MN) OCT systems, we utilized ex-vivo preparations of arterial segments. Ocelot and Dragonfly catheters were inserted into identical cadaveric femoral peripheral arteries for image acquisition and interpretation. Three independent physician interpreters assessed the images to establish accuracy and sensitivity of the diagnostic information. Histologic evaluation of the corresponding arterial segments provided the gold standard for image interpretation. In vivo clinical images were obtained during therapeutic interventions that included crossing of peripheral chronic total occlusions (CTOs) using the Ocelot catheter.

RESULTS

Strong concordance was demonstrated when matching image characteristics between both OCT systems and histology. The Dragonfly and Ocelot system's vessel features were interpreted with high sensitivity (91.1-100%) and specificity (86.7-100%). Inter-observer concordance was documented with excellent correlation across all vessel features. The clinical benefit that the Ocelot OCT system provided was demonstrated by comparable procedural images acquired at the point of therapy.

CONCLUSIONS

The study demonstrates equivalence of image acquisition and consistent physician interpretation of images acquired by the Ocelot and the Dragonfly OCT systems in-spite of distinct image processing algorithms and catheter configurations. This represents a dramatic shift away from both fluoroscopic imaging and diagnostic-only OCT imaging during peripheral arterial intervention towards therapeutic devices that incorporate real time diagnostic OCT imaging. In the clinical practice, these diagnostic capabilities have translated to best-in-class safety and efficacy for CTO crossing using the Ocelot catheter.

Comparative Assessment of Guidewire and Microcatheter vs a Crossing Device-Based Strategy to Traverse Infrainguinal Peripheral Artery Chronic Total Occlusions

PURPOSE

To compare success rates of a guidewire and microcatheter strategy vs the use of specialized crossing devices to traverse infrainguinal peripheral artery chronic total occlusions (CTOs).

METHODS

For this analysis, data on 438 consecutive infrainguinal CTO interventions in 438 patients (mean age 63.2 years; 402 men) performed between August 2006 and May 2014 were extracted from the multicenter Excellence in Peripheral Artery Disease (XLPAD) database (ClinicalTrials.gov; identifier NCT01904851). Primary technical success constituted placement of a guidewire in the true lumen, past the distal CTO cap, with the initial crossing strategy.

RESULTS

A wire-catheter strategy was used in 295 (67.4%) and a specialized CTO crossing device in 143 (32.6%) patients (p<0.001). Primary crossing technical success was higher with CTO devices (72.1% vs 51.9%, p<0.001). The primary wire-catheter arm used significantly more secondary CTO devices (28.1% vs 17.5%) and/or provisional re-entry devices (26.7% vs 4.9%) compared with the primary CTO device arm (both p<0.001). Secondary crossing technical success (defined as crossing with an alternate strategy: 67.5% vs 71.4%, p=1.000), provisional crossing technical success (defined as use of a re-entry device: 84.2% vs 87.5%, p=0.768), and procedure success (93.6% vs 90.9%, p=0.332) were similar between the wire-catheter and CTO device strategies, respectively. No differences were observed in periprocedural complications or 30-day adverse events; however, at 12 months, there was a significantly higher surgical revascularization rate in the primary wire-catheter arm (8.8% vs 2.8%, p=0.025).

CONCLUSION

Infrainguinal peripheral artery CTO crossing is frequently attempted with a wire-catheter technique; however, an initial CTO crossing device approach is associated with higher primary technical success. Overall procedure success is similar with both strategies.

Distal macro- and microembolization during subintimal recanalization of femoropopliteal chronic total occlusions

PURPOSE

To investigate the phenomenon of distal embolization during subintimal angioplasty with or without stenting of femoropopliteal chronic total occlusions (CTOs).

METHODS

This prospective study included 40 consecutive patients (35 men; mean age 65.4±9.3 years) who underwent subintimal angioplasty alone (n=14) or with stenting (n=26) of CTOs in the femoropopliteal segment. A Spider protection filter was used to capture any possible macro- or microemboli generated during balloon inflation/stenting. Arterial outflow was angiographically checked during each consecutive procedural step. All filters were examined on site for macroscopic material, while the first 20 filters underwent further histopathological qualitative and semiquantitative analysis using a 0+ to 3+ score.

RESULTS

There was no angiographically or clinically evident distal embolization. Macroscopic particulate debris was not detected in any filter. Histopathology confirmed the absence of macroemboli but revealed microembolic material (diameter <100 μm) in all filters (20/20). The mean number of particles detected was 9.4±4.5 (range 5-17). Histopathological findings included fibrin conglomerates (20/20), trapped erythrocytes (19/20), inflammatory cells (16/20), calcification minerals (6/20), extracellular matrix (6/20), cholesterol clefts (6/20), and endothelial cells (6/20). Captured material was classified as fresh and old thrombus in 7/20 and 4/20 cases, respectively. Semiquantitative analysis demonstrated that the collected microparticles consisted primarily of fibrin conglomerates (median score 2+), trapped erythrocytes (median score 1+), and inflammatory cells (median score 1+).

CONCLUSION

Macroscopically evident emboli were not detected following subintimal angioplasty or stenting of femoropopliteal CTOs. Microscopic debris was present in all filters. The clinical significance of the phenomenon remains to be determined.