Crossing techniques and devices in femoropopliteal chronic total occlusion intervention

Evaluation of acute and midterm outcomes after complex combined antegrade/retrograde recanalization for occlusions of the femoropopliteal and infrapopliteal arteries

BACKGROUND

When antegrade recanalization of femoropopliteal and/or infrapopliteal occlusions fails, retrograde access has become an established option. To evaluate the results of combined antegrade and retrograde recanalization of femoropopliteal and infrapopliteal occlusions, patients undergoing secondary retrograde recanalization attempts were analyzed retrospectively.

METHODS

The primary end point was the success of the procedure (successful occlusion crossing using the antegrade/retrograde technique). Secondary end points include complication rate, primary patency and target lesion revascularization (TLR) rate, amputation rate, changes in ankle-brachial index, and Rutherford-Becker class. Predictors for procedure failure and TLR were analyzed.

RESULTS

We included 888 patients: 362 with femoropopliteal (group 1), 353 with infrapopliteal (group 2), and 173 with multilevel (group 3) recanalization. Critical limb-threatening ischemia was present in group 1, 2, and 3 in 36%, 62%, and 76% of patients, respectively. The intervention was successful in 92.5%, 93.8%, and 90.8% of the respective cases (P = .455). The overall peri-interventional complication rate was 7.2%. At 6, 12, and 24 months, primary patency was highest in group 1 (63.9%, 45.8%, and 33.3%), followed by group 3 (59.8%, 46.1%, and 33.3%), and group 2 (58.5%, 43.1%, and 30.4%; P = .537). The risk of undergoing repeated TLR within 24 months was 31.4% for group 1, 39.1% for group 2, and 45.7% for group 3. At 24 months, the survival rates in groups 1, 2, and 3 were 93.8%, 79.4%, and 87.5%, respectively. Over 24 months, 75 patients (8.4%) had to undergo amputation. Significant improvements in both ankle-brachial index and Rutherford-Becker class were present at discharge as well as at 6, 12, and 24 months (P < .001). Dialysis dependency was a predictor of unsuccessful antegrade/retrograde recanalization (P = .048). Lesion length (P = .0043), dialysis (P = .033), and recanalization level (P = .013) increase the risk of TLR.

CONCLUSIONS

Using a combined antegrade/retrograde access, recanalization of occluded femoropopliteal and/or infrapopliteal arteries can be achieved in a large number of cases. Owing to the high rate of repeated TLR across all lesion localizations, the indication for antegrade and retrograde recanalization may be limited to patients with critical limb-threatening ischemia.

Recanalization of superficial femoral artery chronic total occlusion through retrograde popliteal approach recanalization of superficial femoral artery chronic total occlusion

Purpose

This retrospective study aims to evaluate the safety, practicality, and efficacy of the independent retrograde popliteal approach for recanalization superficial femoral artery (SFA) occlusions when the bilateral common femoral artery approach is unavailable, such as after endovascular aneurysm repair or common iliac artery stenting.

Methods

This treatment was considered for patients with contralateral iliac artery occlusion, severe iliac tortuosity, or those who had previously undergone endovascular aneurysm repair or common iliac stenting. Patients with SFA lesions extending into the P1-P2 segment of the popliteal artery or with calcification in the P3 segment were excluded. Angioplasty and stenting were conducted via the popliteal artery approach, with hemostasis at the puncture site achieved using an EXOSEAL vascular closure device. Patients were routinely followed up at 3, 6, and 12 months, and annually thereafter.

Results

Forty-eight consecutive patients with SFA occlusion who underwent endovascular treatment via the retrograde popliteal artery approach were included in this study. Retrograde puncture of the popliteal artery was successful in all cases. Six-French sheaths were utilized in all procedures. The EXOSEAL vascular closure device was successfully applied in all 48 cases. No instances of pseudoaneurysms, arteriovenous fistulas, major bleeding, or embolic complications were observed. The technical success rate for SFA recanalization was 100 %. All patients experienced clinical improvement. The ankle-brachial index significantly increased from an initial 0.33 ± 0.11 at admission to 0.81 ± 0.19 at discharge (P < 0.001). The mean follow-up period was 25.1 ± 11.7 months. Kaplan-Meier analysis revealed primary patency rates of 82.5 % at 12 months and 71.8 % at 24 months. No patients required major amputation during the follow-up period.

Conclusion

The endovascular treatment of SFA occlusions via the independent retrograde popliteal approach is a viable alternative, demonstrating a low incidence of puncture-related complications and a high success rate of recanalization.

Design, Optimization, and Modeling of a Hydraulic Soft Robot for Chronic Total Occlusions

Chronic total occlusion (CTO) is one of the most severe and sophisticated vascular stenosis because of complete blockage, greater operation difficulty, and lower procedural success rate. This study proposes a hydraulic-driven soft robot imitating the earthworm's locomotion to assist doctors or operators in actively opening thrombi in coronary or peripheral artery vessels. Firstly, a three-actuator bionic soft robot is developed based on earthworms' physiological structure. The soft robot's locomotion gait inspired by the earthworm's mechanism is designed. Secondly, the influence of structure parameters on actuator deformation, stress, and strain is explored, which can help us determine the soft actuators' optimal structure parameters. Thirdly, the relationship between hydraulic pressure and actuator deformation is investigated by performing finite element analysis using the bidirectional fluid-structure interaction (FSI) method. The kinematic models of the soft actuators are established to provide a valuable reference for the soft actuators' motion control.

Differences between Lower Extremity Arterial Occlusion vs. Stenosis and Predictors of Successful Endovascular Interventions

Background and Objectives: In patients with peripheral artery disease, there is insufficient understanding of characteristics that predict successful revascularization of the lower extremity (LE) chronic total occlusions (CTOs) and baseline differences in demographic, clinical, and angiographic characteristics in patients with LE CTO vs. non-CTO. We aim to explore these differences and predictors of successful revascularization among CTO patients. Materials and Methods: Two vascular centers enrolled LE-CTO patients who underwent endovascular revascularization. Data on demographics, clinical, angiographic, and interventional characteristics were collected. LE non-CTO arterial stenosis patients were compared. A total of 256 patients with LE revascularization procedures were studied; among them, 120 had CTOs and 136 had LE stenosis but no CTOs. Results: Aspirin use (Odds ratio, OR: 3.43; CI 1.32-8.88; p = 0.011) was a positive predictor whereas a history of malignancy (OR: 0.27; CI 0.09-0.80; p = 0.018) was a negative predictor of successful crossing in the CTO group. The CTO group had a higher history of myocardial infarction (29.2 vs. 18.3%, p = 0.05), end-stage renal disease (19.2 vs. 9.6%, p = 0.03), and chronic limb-threatening ischemia as the reason for revascularization (64.2 vs. 22.8%, p < 0.001). They were more likely to have advanced TransAtlantic Inter-Society Consensus (TASC) stages, multi-vessel revascularization procedures, longer lesions, and urgent treatment. Conclusions: The use of aspirin is a positive predictor whereas a history of malignancy is a negative predictor for successful crossing in CTO lesions. Additionally, LE-CTO patients have a higher incidence of comorbidities, which is expected given their higher disease burden. Successful endovascular re-vascularization can be associated with baseline clinical variables.

Feasibility of the Complete Endovascular Reconstruction of the Trifurcation (CERT) Technique for Revascularisation in Chronic Limb Threatening Ischemia

BackgroundRevascularisation of patients with chronic limb threatening ischaemia due to arterial lesions in the below the knee segment can be challenging. This study describes a novel technique that allows a complete endovascular reconstruction of the trifurcation (CERT) utilising stents in the below the knee segment when conventional techniques are exhausted, or have failed to deliver an acceptable result, leading to remaining outflow compromise. Methods: Eight patients with Rutherford 5 chronic limb threatening ischaemia underwent CERT between January 1st, 2018 and January 1st, 2020. All patients underwent ultrasound at 6 weeks post operatively and then at variable intervals until the completion of the follow up period in March 2020. Results: Technical success of the CERT technique was achieved in all patients. Six patients had anterior tibial artery/Tibioperoneal trunk reconstructions, whilst 2 patients were stented directly into posterior tibial and peroneal artery. Five patients (63%) achieved wound healing. All-cause mortality was 25% (2 patients) with 1 patient achieving wound healing prior to death. Two stents were occluded during the follow up period. The first was asymptomatic and had achieved wound healing. The second was symptomatic with stent occlusion and a delayed presentation with Rutherford 3 acute limb ischaemia. Conclusions: Complete endovascular reconstruction of the trifurcation is a feasible option to achieve revascularisation in patients with tissue loss and below the knee arterial lesions allowing a continuous reconstruction of the trifurcation segment keeping the anatomical configuration intact. Clinical outcomes appear acceptable however larger series are needed.

Endovascular Materials and Their Behavior in Peripheral Vascular Surgery

Endovascular techniques have progressively become the first option for the treatment of stenosis and occlusions of both aorto-iliac and femoro-popliteal district. The development of new technologies and new materials has broadened the applicability of the endovascular techniques, allowing the treatment of each lesion with the most suitable material. A knowledge of the behavior of endovascular materials when treating peripheral arterial disease (PAD) is, therefore, crucial for optimization of the results. Here, we aim to review the most important technical features of the actually available endovascular materials for treating PAD.

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.

Successful Peripheral Vascular Intervention in Patients with High-risk Comorbidities or Lesion Characteristics

PURPOSE OF REVIEW

Certain comorbidities and lesion characteristics are associated with increased risk for procedural complications, limb events, and cardiovascular events following peripheral vascular intervention (PVI) in patients with peripheral arterial disease (PAD). The purpose of this review is to provide an overview of high-risk modifiable and unmodifiable patient characteristics and its relative impact on clinical outcomes such as amputation risk and mortality. Furthermore, general approaches to potentially mitigating these risks through pre-intervention planning and use of modern devices and techniques are discussed.

RECENT FINDINGS

Diabetes, tobacco use, and older age remain strong risk factors for the development of peripheral arterial disease. Recent data highlight the significant risk of polyvascular disease on major limb and cardiac events in advanced PAD, and ongoing studies are assessing this risk specifically after PVI. Challenging lesion characteristics such as calcified disease and chronic total occlusions can be successfully treated with PVI by utilizing novel devices (e.g., intravascular lithotripsy, re-entry devices) and techniques (e.g., subintimal arterial "flossing" with antegrade-retrograde intervention). Understanding high-risk patient comorbidities and lesion characteristics will improve our ability to counsel and manage patients with advanced PAD. Continued device innovation and novel techniques will aid in procedural planning for successful interventions to improve clinical outcomes.

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.

"Failure-to-Cross" in Patients Undergoing Percutaneous Peripheral Intervention: The Nonreimbursed Procedure

BACKGROUND

Percutaneous peripheral intervention (PPI) is often the first mode of therapy for patients with symptomatic arterial occlusive disease. Technical success generally remains high although "failure-to-cross" still complicates 5-20% of cases. Extended efforts to cross long, occlusive lesions can utilize significant hospital and practitioner resources. The hospital is typically reimbursed for this effort as facility fees are charged by the hour and materials are charged per use. However, given the lack of a CPT® code for "failure-to-cross," practitioners are rarely appropriately compensated. The purpose of this study is to analyze the predictors, technical details, outcomes, and costs of "failure-to-cross" during PPI.

METHODS

All PPI procedures over a 2-year period at a single institution were retrospectively reviewed. Clinical characteristics, results, costs, and reimbursements obtained from hospital cost accounting were compared among successful therapeutic interventions, crossing failures, and diagnostic angiograms without attempted intervention.

RESULTS

A total of 146 consecutive PPIs were identified; the rate of "failure-to-cross" was 11.6% (17 patients). The majority of patients with "failure-to-cross" were male (82%) with single-vessel runoff (53%). Compared to successful interventions, the incidences of chronic limb-threatening ischemia (82% vs. 70%, P = 0.34) and infrapopliteal occlusive disease were similar (47% vs. 31%, P = 0.20). "Failure-to-cross" procedures were just as long as successful procedures; there were no significant differences in fluoroscopy time (27 ± 10 vs. 24 ± 14 min, P = 0.52), in-room time (106 ± 98 vs. 103 ± 44 min, P = 0.84), or contrast dye volume utilization (73 ± 37 vs. 96 ± 54 mL, P = 0.12). As expected, "failure-to-cross" procedures incurred far higher hospital charges and costs compared to noninterventional diagnostic angiograms (charges $13,311 ± 6,067 vs. $7,690 ± 1,942, P < 0.01; costs $5,289 ± 2,099 vs. $2,826 ± 1,198, P < 0.01). Despite the additional time and effort spent attempting to cross difficult lesions, the operators were reimbursed at the same low rate as a purely diagnostic procedure (average fee charge $7,360; average reimbursement $992). After 1 year, the 17 patients in whom lesions could not be crossed were treated with advanced interventional procedures with success (n = 2), surgical bypass grafting (n = 5), extremity amputation (n = 4), or no additional intervention in their salvaged limb (n = 6).

CONCLUSIONS

Patients whose lesions cannot be crossed during PPI fare worse than patients undergoing successful interventions. Hospital costs and charges appropriately reflect the high technical difficulty and resource utilization of extended attempts at endovascular therapy. For practitioners, crossing lesions during PPI is truly a "pay-for-performance" procedure in that only successful procedures are reasonably reimbursed.

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.

Retrograde Popliteal Access and Balloon Dilatation of Chronic Total Occlusion of Superficial Femoral Arteries

BACKGROUND

The objective of the study was to evaluate the effectiveness of retrograde popliteal access in subjects with chronic total occlusion of the superficial femoral artery.

METHODS

A retrospective review of subjects who underwent balloon dilatation via retrograde popliteal access (RPA) is included. Age, gender, tobacco use, comorbid diseases, body mass index, ejection fraction, claudication distance (0 to 50 meters, 50 to 100 meters and 100 to 150 meters), preoperative Rutherford scale, and Ankle-brachial index (ABI) are noted for each subject. A duplex ultrasound (DUS) was performed preoperatively. The localization side of the lesion (right-left), the length of the atherosclerotic segment, and the localization of the diseased segment (proximal superficial femoral artery [SFA], mid-SFA, distal SFA, popliteal-above the knee) were noted. Subjects were followed for at least one year after the procedure. Subjects were reevaluated in the first, 6th, and 12th months after the procedure. In control subjects, Rutherford class and ABI were noted. A DUS was performed to detect restenosis. The subjects' preoperative Rutherford class and ABI and restenosis degree were compared with their postoperative values.

RESULTS

A total of 93 subjects (75.3% male, 24.7% female; mean age 68.57 ± 8.70 years old) were evaluated. In all 93 (100%) subjects, successful RPA was achieved. Overall, balloon dilatation via RPA was successful in 86 (92.47%) of the 93 subjects. The procedural success rate was 92.47%. The occluded segment was on the right side in 49.5% of the subjects (n = 46) and on the left side in 50.5% (n = 47) of the subjects. The mean length of the lesion was 10.77 ± 2.21 cm, and the average stenosis degree was 95.9 ± 5.05%. The localization of the occluded segment was in the proximal SFA, mid SFA, distal SFA and popliteal above the knee in 45.2%, 50.5%, 25.8% and 10.8% of the patients, respectively.When comparing the successful and unsuccessful groups, target lesion length (10.48 ± 2.01 vs. 14.43 ± 0.79, P < 0.001), mid-SFA localization (n = 40 vs. n = 7, P = 0,012) and claudication distance in the first 50 meters (P = 0,003) were significantly higher in subjects with failed balloon dilatation via RPA. When the Rutherford scale was examined, the mild, moderate, and severe claudication ratios were 23.7%, 29%, and 47.3%, respectively. After the procedure, 61.3% of the cases were asymptomatic, and 38.7% had mild claudication. The change in the Rutherford scale was statistically significant (P < 0,001). When the ABI measurements were examined before procedure, it increased from 0.63 ± 0.08 before to 0.90 ± 0.06 after the procedure, indicating a statistically significant difference (P < 0,001). When Doppler findings were examined, in the successful RPA group, the no-stenosis percentages were 82.6%, 72.1%, and 65.1 at the first, 6th, and 12th month follow-up, respectively. The mean disease-free survival time was 9.80 ± 0.39 months. In the first year, subjects were divided according to stenosis degree. Subjects with less than 50% stenosis were compared with subjects with more than 50% stenosis to detect the preprocedural characteristics that affect the restenosis degree. Tobacco use, chronic obstructive pulmonary disease, hyperlipidemia, chronical renal insufficiency, and popliteal above the knee localization were significantly higher in subjects who had more than 50% stenosis 1 year after the procedure (P = 0.009, P = 0.015, P = 0.044, P = 0.001, and P = 0.017, respectively).

CONCLUSIONS

RPA under DUS guidance is an effective method. RPA has high procedural success rate with low morbidity. Longer target lesion length, mid-SFA localization, and claudication distance in first 50 meters found to be related factors with RPA balloon dilatation failure. Restenosis rates after 12 months of follow-up is low and comparable with literature.