One-year results from the DETOUR I trial of the PQ Bypass DETOUR System for percutaneous femoropopliteal bypass

A Bibliometric Analysis on Adherence to Reporting Standards for Endovascular Treatment of Chronic Lower Extremity Peripheral Artery Disease

BACKGROUND

The treatment of chronic limb-threatening ischemia (CLTI) involves a broad spectrum of therapies including many new and emerging techniques. To standardize the results of studies examining this pathology and to allow critical analysis and comparison between studies, the Society for Vascular Surgery (SVS) recommended reporting standard guidelines for the endovascular management of CLTI in 2016. Research studies that do not adhere to complete reporting standards are often more ambiguous in impact and external validity, leading to bias and misinformation that has potentially damaging effects on clinical decision-making. We thus sought to examine adherence to and factors associated with noncompliance with these recommended guidelines.

METHODS

A literature database search was conducted to include all clinical trials, randomized controlled trials, and retrospective comparative studies written in English examining the endovascular treatment of peripheral artery disease (PAD)/CLTI from January 2020 to August 2022. Systematic reviews, case reports, and meta-analysis were excluded. The manuscripts were reviewed for adherence with the SVS guidelines (overall and by guideline subcategories based on demographics, treatment methods, and outcomes), and factors associated with this adherence were determined. These data were used to calculate descriptive and comparative statistics.

RESULTS

Fifty-four manuscripts were identified from this time frame. On average, articles reviewed reported on 42.0% of the SVS reporting standards (range, 25.0-65.2%, Fig 1) with 74.1% of articles (n = 40) not adhering to at least 50.0% of the standards. Manuscripts most completely followed guidelines regarding "patient factors" and were least likely to demonstrate adherence to the description of CLTI and study complications. Within the guideline subcategories, complete adherence to guidelines was not demonstrated in any manuscript in stent trials, disease outcome measures, technical outcome measures, patient factors and critical limb ischemia description, and complete adherence rates within the other subcategories was low (range, 5.6-18.6%). Studies conducted within the United States and those with industry sponsorship were more likely to adhere to >50% of the reporting standards (P < 0.05). Journal impact factor, year of publication, and number of authors had no correlation to the percent adherence to guidelines in specific categories or adherence overall.

CONCLUSIONS

Adherence to reporting standard guidelines for endovascular treatment of lower extremity PAD specifically outlined by the SVS is suboptimal regardless of the quality of the journal the research is published in. Increasing adherence to reporting standards to provide a framework for comparison of studies across techniques used should be prioritized by authors, journal editors, and vascular societies.

DETOUR2 trial outcomes demonstrate clinical utility of percutaneous transmural bypass for the treatment of long segment, complex femoropopliteal disease

OBJECTIVE

Percutaneous transmural arterial bypass (PTAB) using the DETOUR system aims to create a percutaneous, endovascular femoropopliteal bypass for the treatment of long segment, complex superficial femoral and proximal popliteal artery disease. The goal of the DETOUR2 study is to investigate the safety and effectiveness of the therapy in comparison with pre-established performance goals.

METHODS

The DETOUR2 investigational device exemption study is a prospective, single-arm, multicenter, international trial of symptomatic peripheral arterial disease patients (Rutherford classes 3-5) undergoing the DETOUR procedure for long segment (>20 cm) superficial femoral artery disease. Prespecified end points included primary safety (composite of major adverse events) at 30 days, and effectiveness (primary patency defined as freedom from restenosis or clinically driven target lesion revascularization) at 1 year.

RESULTS

We enrolled 202 patients at 32 sites with 200 treated with the DETOUR system. The mean lesion length was 32.7 cm, of which 96% were chronic total occlusions (CTO) and 70% were severely calcified. Technical success was achieved in 100% of treated patients. The primary safety end point was met with a 30-day freedom from major adverse event rate of 93.0%. The 1-year primary effectiveness end point was met with 72.1% primary patency at 12 months. Primary-assisted and secondary patency were 77.7% and 89.0%, respectively, at 12 months. The 12 month deep venous thrombosis incidence was 4.1% with no pulmonary emboli reported. Venous quality-of-life scores showed no significant changes from baseline. There was a Rutherford improvement of at least one class through 12 months in 97.2% of patients. The mean ankle-brachial index also improved from 0.61 to 0.95 during this period. There were marked improvements in quality-of-life and functional status measures.

CONCLUSIONS

The DETOUR2 study met both the primary safety and effectiveness end points, demonstrating clinical usefulness of this novel therapeutic strategy in long femoropopliteal lesions.

Endovascular Transvenous versus Open Femoropopliteal Bypass

Background and Objectives: Lower extremity arterial disease is one of the most prevalent manifestations of atherosclerosis. The results from numerous studies regarding the best revascularization method of an occluded superficial femoral artery have been conflicting. The aim of this study was to compare the patency of transvenous endovascular with open femoropopliteal bypass, both with vein and prosthetic grafts. To our knowledge, a direct patency comparison between transvenous endovascular and open femoropopliteal bypass has not been published. This could help elucidate which method is preferable and in which cases. Materials and Methods: Patients with complex TASC-C and D SFA lesions were offered endovascular transvenous or open bypass. A total of 384 consecutive patients with PAD requiring surgical treatment were evaluated for inclusion in this study. Three-year follow-up data were collected for 52 endovascular procedures, 80 prosthetic grafts, and 44 venous bypass surgeries. Bypass patency was investigated by Duplex US every 6 months. Kaplan-Meier plots were used to analyze primary, primary-assisted, and secondary patency for endovascular transvenous, autovenous, and prosthetic bypasses. Results: Primary, primary-assisted, and secondary patency in venous group at 3 years was 70.5%, 77.3%, and 77.3%, respectively. In the endovascular transvenous group, primary, primary-assisted, and secondary patency at 3 years was 46.2%, 69.2%, and 76.9%, respectively. The lowest patency rates at 3 years were noted in the prosthetic graft group with 22.5% primary, 26.6% primary-assisted, and 28.2% secondary patency. Conclusions: The saphenous vein is the best graft to perform in above-the-knee femoropopliteal bypass. Transvenous endovascular bypass is a viable option with comparable primary-assisted and secondary patency. Primary patency is substantially lower for endovascular transvenous compared to venous bypass. Patients treated with endovascular transvenous bypass will require a significant number of secondary procedures to provide optimal patency. Prosthetic grafts should only be used if no other option for bypass is available.

Technique and early results of percutaneous femoropopliteal bypass with stent graft

Objective

We describe the technique and early results of lower extremity revascularization with total percutaneous bypass using extravascular placement of a stent graft (percutaneous prosthetic bypass).

Methods

Patients with severe chronic limb threatening ischemia for whom open or endoluminal repair was either not feasible and or had failed were selected for a pilot study using percutaneous prosthetic bypass. The procedure requires placement of three introducer sheaths in the contralateral common femoral artery, and the ipsilateral proximal and distal superficial femoral arteries (SFAs). A guidewire is placed from the contralateral sheath to the ipsilateral popliteal artery via the two ipsilateral sheaths. Two self-expanding polytetrafluoroethylene-covered stents are then placed from the proximal SFA to the distal SFA.

Results

A total of 30 bypasses were performed in 28 patients aged 71 ± 3 years. Of the 28 patients, 16 had severe claudication (Rutherford class 3; 53%) and 14 had critical ischemia (Rutherford class 4-6; 47%). The early results were excellent, with no deaths and one occlusion successfully treated with thrombolysis. No other complications requiring reintervention occurred. The mean follow-up was 25.4 months (range, 3-36 months). The 12- and 36-month Kaplan-Meier survival curve was 100% and 81%, respectively. The primary patency, secondary patency, and freedom from amputation rates were 75% and 75%, 78% and 75%, and 100% and 91%, respectively.

Conclusions

For patients with long lesions and/or failed endovascular treatment, the described technique offers the advantage of a total percutaneous procedure with acceptable early results. If these favorable outcomes are confirmed in larger series with longer follow-up, percutaneous extravascular bypass of the SFA will represent a complementary tool for infrainguinal arterial repair.

Endovascular Interventions for Peripheral Artery Disease: A Contemporary Review

PURPOSE OF REVIEW

Peripheral artery disease (PAD) is an increasingly prevalent but frequently underdiagnosed condition that can be associated with high rates of morbidity and mortality. While an initial noninvasive approach is the cornerstone of management, revascularization is often pursued for patients with treatment-refractory claudication or chronic limb-threatening ischemia (CLTI). In this review, we discuss the current state of endovascular interventions for PAD and explore the many new emerging technologies.

RECENT FINDINGS

The last decade has resulted in numerous advances in PAD interventions including the ongoing evolution of drug-coated devices, novel approaches to complex lesions, and contemporary evidence from large clinical trials for CLTI. Advances in endovascular management have allowed for increasingly complex lesions to be tackled percutaneously. Future directions for the field include the continued evolution in device technology, continued development of state-of-the-art techniques to revascularization of complex lesions, and increased collaboration between a largely multidisciplinary field.

Clampless 2 Device: Experimental Study of a Lateral Aorto-Prosthetic Anastomosic Device Without Clamping or Suturing

BACKGROUND

To offer an alternative to conventional techniques of lateral prosthetic anastomosis on arteries which require a long training, and impose an extensive open surgery, we are proposing the clampless 2 device (C2D) implanted by a simple arterial puncture and allows a lateral implantation of a polytetrafluoroethylene (PTFE) vascular graft in an artery, without arterial clamping or suture.

METHODS

C2D is a "T" shaped 25-mm long and 8-mm diameter Nitinol stent with a 6-mm PTFE graft prosthesis mounted laterally on the stent, and implanted in an artery, via a 21-French sheath, and a compliant balloon inflation. In vitro testing of the C2D was first performed on a bench including a segment of a 7-mm internal diameter pig abdominal aorta. A series of 5 consecutive C2D implantation was analyzed with evaluation of the implantation time and the fluid losses at a fluid pressure of 80 and 150 mm Hg. The C2D implantation was finally controlled by angioscopy. An aorto-iliac bypass was then secondly performed on 8 living sows, with a side-to-end C2D implantation in the infrarenal abdominal aorta, followed by a conventional end-to-end prosthetic left iliac trunk anastomosis. The C2D and distal conventional anastomotic times were evaluated, as well as the total operative time and blood loss. A postoperative angiogram was systematically performed.

RESULTS

The C2D was successfully implanted in all 5 in vitro tests, with an average implantation time of 2'58 (range: 2'25-3'22). The mean value of fluid losses was 84 ml (range: 67-94 ml), with no fluid leakage occurring at 80- and 150-mm Hg pressure. All anastomoses were patent after macroscopic study by angioscopy with a perfect application of the stent in the aortic wall. In 8 living sows (mean weight: 42 kg, 37-50 kg), an aorto-left iliac bypass was successfully implanted in all cases, with a total mean procedure time of 101 min (range: 90-130 min), and an average fluid loss of 77 ml (range:20-120 ml). The mean implantation time was 4'39 (range 3'29-5'52) for C2D and 16 min (range 12-17 min) to perform the conventional distal prosthetic-iliac anastomosis. Systematic arteriographic and angioscopy control showed perfect patency of the C2D implantations.

CONCLUSIONS

Preliminary in vitro and acute in vivo testing of C2D implantation show good early results, allowing further long-lasting pig experiments on the way to human homologation.

Long term clinical and functional venous outcomes after endovascular transvenous femoro-popliteal bypass

BACKGROUND

Peripheral artery disease is widespread in Western societies affecting around 13% of the population above 50 years of age. Despite recent improvements of endovascular treatment, open surgical bypass is still recommended as the treatment of choice for long segment TASC D lesions. The DETOUR procedure was introduced as an endovascular alternative in cases of long-segment superficial femoral artery occlusion. This unconventional technique raises several questions regarding the effect of the bypass graft on femoral venous physiology.

METHODS

We conducted a 3-year follow-up study of subjects enrolled and treated in the prospective, multicenter DETOUR study at the Pauls Stradins clinical university hospital, Riga, Latvia. In total, 52 consecutive patients (54 procedures) were enrolled in this study from 2015 until 2019. We performed Venous Clinical Severity Score (VCSS) and Villalta (VS) Score assessments, Duplex ultrasound measuring femoral and popliteal vein diameters, venous occlusion plethysmography and digital photoplethysmography to assess and compare venous physiology at baseline and at follow-up visits every 6 months.

RESULTS

At baseline mean femoral vein diameter was 11.1 mm (SD=1.5). At 36-months following intraluminal stent-graft placement, mean femoral vein diameter was 11.1 mm (SD=1.7) with no evidence of enlargement of the femoral vein (P=0.2). Popliteal vein diameter was not significantly changed during 24-months of follow-up (P=0.12) but showed a small (0.02 mm) statistically significant decrease in diameter at 36-months compared to baseline. During the study period, only one patient (1.9%) developed clinically significant ipsilateral DVT 1-month after surgery. Clinically silent femoral venous thrombosis was documented in 8 legs during 36-month follow-up. In one case the thrombus was occlusive and in 7 cases the thrombus was non-occlusive. At baseline, 48 of 52 patients (92%) had no or minor venous symptoms ([VCSS 0-2] with clinically significant venous symptoms in only 4 patients [VCSS≥3]). At one-month follow-up, the venous clinical severity score increased in all patients compared to baseline. At 6-month follow-up, the VCSS had returned to baseline in the majority of patients with no significant changes during the 3-year follow-up period. At baseline, all patients had a VS of 0-2 indicating minor or no venous symptoms (mean 0.4 [SD 0.7]). At the 1-month follow-up visit 3 patients (5.8%) had a VS≥3 (two patients had a score of 3 and one patient a score of 4), indicating significant venous symptoms. At the 6-month visit and thereafter, all the VS in all patients had returned to baseline. Transvenous endovascular procedure did not significantly alter venous physiology in treated leg.

CONCLUSIONS

Percutaneous transvenous femoropopliteal bypass provided safe and effective lower-extremity revascularization with minimal effect on long-term venous function. The femoral and popliteal vein remained patent with no compensatory enlargement in response to the presence of the bypass graft within the femoral vein. During 3-year follow-up there were no significant changes in venous symptom scores or physiologic function.

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

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

Novel Therapies for Critical Limb-Threatening Ischemia

PURPOSE OF REVIEW

This review intends to discuss the latest endovascular and surgical advancement in the treatment of critical limb-threatening ischemia (CLTI).

RECENT FINDINGS

We discuss novel endovascular technological advancements such as intravascular lithotripsy, the Tack endovascular stent, the PQ Bypass DETOUR system, and the LimFlow System for deep venous arterialization (DVA) in the very high risk "no-option" CLTI population. We also discuss the increasing adoption of radial and pedal approaches for endovascular revascularization and the tibiopedal arterial minimally invasive (TAMI) technique. On the surgical front, we discuss the distal vein patch technique and surgical and hybrid DVA. Recent advancements in the treatment options of CLTI will likely lead to reducing the rate of major amputations if they are adopted in a collaborative environment in order to apply the most appropriate treatment option to each individual patient based on the anatomy, comorbidities, functional status, and local expertise.

Percutaneous Femoropopliteal Bypass: 2-Year Results of the DETOUR System

PURPOSE

This study investigated the 2-year safety and effectiveness of the PQ Bypass DETOUR system as a percutaneous femoropopliteal bypass.

MATERIALS AND METHODS

Seventy-eight patients with 82 long-segment femoropopliteal lesions were enrolled in this prospective, single-arm, multicenter study. The DETOUR system deployed Torus stent grafts directed through a transvenous route. Eligible patients included those with lesions of >10 cm and average of 371±55 mm. Key safety endpoints included major adverse events (MAEs) and symptomatic deep venous thrombosis in the target limb. Effectiveness endpoints included primary patency defined as freedom from ≥50% stenosis, occlusion, or clinically-driven target vessel revascularization (CD-TVR), primary assisted, and secondary patency.

RESULTS

Chronic total occlusions and severe calcium occurred in 96% and 67% of lesions, respectively. Core laboratory-assessed total lesion length averaged 371±51 mm with a mean occlusion length of 159±88 mm. The rates of technical and procedural success were 96%, with satisfactory delivery and deployment of the device without in-hospital MAEs in 79/82 limbs. The MAE rate was 22.0%, with 3 unrelated deaths (4%), 12 CD-TVRs (16%), and 1 major amputation (1%). Deep venous thrombosis developed in 2.8% of target limbs, and there were no reported pulmonary emboli. Primary, assisted primary, and secondary patency rates by the Kaplan-Meier analysis were 79±5%, 79±5%, and 86±4%, respectively.

CONCLUSIONS

The PQ Bypass DETOUR system is a safe and effective percutaneous alternative to femoropopliteal open bypass with favorable results through 2 years. The DETOUR system provides a durable alternative to conventional endovascular modalities and open surgery for patients with long, severely calcified, or occluded femoropopliteal lesions.

The "Needle bypass" technique: Percutaneous anatomical bypass with needle rendezvous for patients with peripheral arterial disease that have no other surgical options

BACKGROUND

The ideal method for recanalization of complex peripheral lesions has not been determined, despite the use of the latest endovascular devices. We describe a novel method for a fully percutaneous anatomical bypass, named the "needle bypass" technique, for treatment of complex vascular lesions with failed previous surgical therapy.

MAIN TEXT

A 68-year-old male patient with chronic limb-threatening ischemia presented to our department. He previously had received surgical treatment 10 years prior that included the removal of the right distal common femoral artery and two surgical bypasses, an axillary-femoral bypass and an iliofemoral bypass, because he had repeated infections. He was referred to our center in order to have peripheral interventions. Since the previous conventional bridging/revascularization of the removed common femoral bifurcation had failed, the "needle bypass" technique was then used. With this novel technique, the tips of two percutaneous and bidirectional inserted needles were aligned ("needle rendezvous") for the externalization of a guidewire in a through-and-through manner. Once this was achieved, an endovascular stent graft and an interwoven stent were deployed to cover and connect the lesion. This new technique is a minimally invasive anatomical bypass that directly connects artery to artery without any disturbance of the venous flow, and this technique, as the only option available, was performed successfully in our no-option patient.

CONCLUSIONS

The "needle bypass" technique is an effective percutaneous treatment method in patients with no other surgical options.

[Innovations in the endovascular treatment of peripheral arterial disease]

The cooperation of physicians, engineers and other sciences results in a steady launching of effective tools for vascular treatment, which further support the dominating position of endovascular therapy in the field of PAD. Parallel to the treatment options, non-radiation based image guidance is another area, where innovation helps to reduce radiation burden for patient and staff members without losing procedural quality and despite a growing number of radiation based procedures. Meanwhile, the available portfolio of endovascular tools allows to treat every vessel segment with results comparable to or even better then open surgery. This survey presents new techniques, tools and recently published results from related trials, which will probably have further influence on PAD treatment in the coming years.

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.

Venous outcomes at 1 year after using the femoral vein as a conduit for passage of percutaneous femoropopliteal bypass

OBJECTIVE

The DETOUR 1 study was performed to assess the safety of the femoral vein as a "pass through" conduit for covered stent placement during fully percutaneous femoropopliteal bypass, also known as the DETOUR procedure.

METHODS

At eight participating centers in this prospective, single-arm, international trial, 78 patients (82 femoropopliteal lesions) were enrolled. All patients had patent femoral veins measuring ≥10 mm in diameter at baseline. The DETOUR procedure involved delivery of a series of TORUS stent grafts, deployed from contralateral common femoral artery access, to the ipsilateral proximal superficial femoral artery, with entry into the femoral vein and re-entry into the arterial vasculature at the above-the-knee popliteal artery. The TORUS stent grafts are deployed in an overlapping configuration as an arterial-arterial conduit. Due to this novel transvenous approach, we assessed specific considerations related to the venous system to analyze the risk of risk of venous thromboembolic complications. Symptomatic deep vein thrombosis, nonocclusive material associated with the graft such as benign endovenous graft-associated material, pulmonary embolism, Venous Clinical Severity Score (VCSS) and Villalta scores, and luminal occupancy by the stent graft were assessed as the ratio of cross-sectional areas of the stent graft to the native vein at baseline and 1 year after the procedure.

RESULTS

A duplicate femoral vein was present in 20.7% of cases. The majority of patients (86.8%) had a femoral vein luminal area preservation of ≥55%. Thirty-two patients experienced an increase in the vein diameter over time after the procedure, but this pattern of venous remodeling was not uniform. The patients who had a compensatory increase in the vein diameter had a smaller average baseline vein diameter compared with the patients who did not have a compensatory increase in vein diameter (P = .0414). Only two patients (2.4%) developed ipsilateral symptomatic deep vein thrombosis) through 1 year of follow-up. There were no pulmonary embolism in any patient in the series. The overall VCSS and Villata scores did not change during follow-up. Mean VCSS and Villata were 0.8 ± 1.4 and 0.5 ± 1.1 at 1 year, compared with 0.6 ± 1.0 and 0.4 ± 0.9 at baseline, respectively.

CONCLUSIONS

As a percutaneous alternative to open surgical bypass for complex femoropopliteal peripheral arterial disease, the transvenous bypass has a low rate of deep venous thrombotic and obstructive complications. Cross-sectional vein area is preserved, and in some patients, the compensatory vein diameter increases with time, supporting the feasibility and safety of using the lower extremity deep venous system as a pass-through conduit for the DETOUR percutaneous femoropopliteal bypass.

TRIAL REGISTRATION

NCT02471638.