Subintimal Angioplasty Research Articles

The Untold Story: Early and Mid-Term Results of Subintimal Angioplasty in Superficial Femoral Artery Versus Popliteal Artery Chronic Total Occlusion.

This study aims to compare the immediate and mid-term outcomes of subintimal angioplasty (SIA) of chronic total occlusions (CTOs) of superficial femoral artery (SFA) versus popliteal artery (PA) and to identify possible predictors of loss of limb-based patency (LBP). This is a retrospective analysis of chronic lower-limb ischemia (CLI) patients (Rutherford classes 3-6) presenting with CTO of SFA or PA treated by SIA and selective stenting in the period 2018 to 2021. Immediate outcomes were compared between the SFA and PA groups, including technical success, perioperative complications, and 30-day major amputation and mortality rates. Mid-term outcomes for technically successful procedures included limb-based patency (LBP), wound healing rate, amputation-free survival (AFS), and major adverse limb events (MALEs). A total of 450 CLI patients underwent SIA of CTO at the SFA (n=260, 57.8%) and the PA (n=190, 42.2%). The indication for revascularization was chronic limb-threatening ischemia in 80.8% of SFA group and 84.2% of PA group. Technical success rate was higher in the PA group compared to the SFA group (96.3% vs 91.2%; p=0.03). The 30-day amputation rates were comparable between the SFA and PA groups (7.7% vs 6.8%, p=0.7, respectively). No perioperative mortality or systemic major complications occurred in the present study. Kaplan-Meier estimate of the 1-year rates were significantly better for SFA group regarding LBP (82% for SFA group vs 43% for PA group, p=0.006), AFS (88% vs 64%, p=0.02), and wound healing (79% vs 58%, p=0.027), respectively. The number of runoff vessels was the only factor associated with loss of LBP (hazard ratio [HR], 0.055; 95% confidence interval [CI]: 0.001-3.020, p=0.039). Subintimal angioplasty is an effective and safe endovascular treatment option of CTO at SFA and PA with satisfactory immediate outcomes. The mid-term outcomes, however, are better for SFA lesions in terms of improved LBP, AFS, and wound healing rates. Subintimal angioplasty is a valuable tool in the armamentarium of endovascular surgeons, as re-entry devices aren't always widely accessible. This study aims to assess the technical outcomes of peripheral vascular interventions for infrainguinal chronic total occlusions and identify possible predictors for successful subintimal angioplasty .Subintimal angioplasty is an effective treatment option for infrainguinal CTO with difference in result of immediate outcomes in popliteal lesions and SFA lesions.

Technical Success, Midterm Primary Patency, and Factors Affecting Primary Patency of Subintimal Angioplasty Followed by Vasculomimetic Stenting for Trans-Atlantic Intersociety Consensus II C and D Femoropopliteal Arterial Disease—A Prospective Study

Abstract Background The best option among the endovascular options in long, complex femoropopliteal (FP) lesions, and factors affecting the patency have yet to be well described. There are few studies describing the mid- and long-term patency of endovascular stents in long-segment FP occlusions. Aim This study aimed to determine the technical success and mid-term patency of subintimal angioplasty with vasculomimetic stenting in Trans-Atlantic Inter-Society Consensus II (TASC) C and D FP disease. The patient and imaging factors that affect primary patency were also analyzed. Methods and Materials A single-center prospective study was performed on 52 consecutive patients undergoing endovascular treatment for TASC C and D FP disease from 2017 to 2021. Angioplasty with stenting was performed in all patients and followed up for 36 months. Endpoints were primary patency rates and amputation-free survival of the limb. Kaplan–Meier curves were used to see patency rates and amputation-free survival rates. Results A total of 52 patients underwent stenting with a technical success rate of 100% if the sub-intimal arterial flossing with antegrade-retrograde intervention (SAFARI) technique was used. Primary stent patency at 6, 12, 18, 24, and 36 months was 89.8, 81.4, 76.2, 71.4, and 62.5%, respectively. Amputation-free survival was 98, 95.6, 91.8, and 85.7% at 12, 24, 30, and 36 months, respectively. Cox proportional regression analysis showed smoking and vessel wall calcium score more than 270 degrees as independent predictors of loss of primary patency (hazard ratio 0.35 confidence interval [CI]: 0.003–0.448) and 0.102 (CI: 0.022–0.47), respectively. Conclusion Subintimal angioplasty with vasculomimetic stent has good midterm patency in and amputation-free survival in long-segment FP occlusions. Smoking and severe vessel wall calcification adversely affect patency.

Peripheral arterial disease (PAD) in diabetics: diagnosis and management- a narrative review.

Peripheral arterial disease (PAD) in diabetic patients is often overlooked due to associated neuropathy. The very first presentation of these patients is with an Ischaemic ulcer or toe gangrene. Diabetics have a very high amputation rate compared to non-diabetic patients due to diffuse multi-segmental disease in the calcified tibial arteries. Early detection of the condition is a challenge in these patients. Even ankle-brachial pressure index may not be reliable. Both surgical and endovascular options are effective in wound healing. Endovascular techniques include percutaneous transluminal angioplasty with and without stenting, sub-intimal angioplasty, percutaneous transluminal angioplasty with drug-coated balloons, covered stents, and use of atherectomy devices. The current narrative review was planned to discuss the essentials of diagnosing PAD in diabetic patients and its various treatment options.

Methods of optimizing the results of endovascular revascularization of infrainguinal arteries (literature review)

With the development of advanced technologies, minimally invasive methods are becoming increasingly widespread in surgery, offering several advantages compared to traditional open surgery. In vascular surgery, endovascular revascularization methods are gaining increasing importance in the management of lower limb occlusive diseases. However, there are certain challenges that limit the effectiveness of endovascular revascularization and increase the likelihood of technical failure. One of the major challenges in endovascular revascularization of lower limb arteries is achieving re-entry into the vessel lumen during subintimal angioplasty.In certain cases, especially when there is severe atherosclerotic involvement of the vessel wall or calcification, the use of standard wire loop techniques may not always allow for re-entry into the true lumen of the vessel, and performing other surgical interventions may be limited or even impossible. Increasing the success rate of subintimal angioplasty will enhance the competitiveness of endovascular revascularization compared to open and hybrid reconstructive surgeries.Several techniques have been proposed to optimize the outcomes of endovascular revascularization, including the SAFARI technique, which combines antegrade and retrograde access for traversing complex occlusions. Re-entry devices equipped with specially curved needles at the catheter tip are used to direct the 0.014 inch wire into the true lumen of the vessel. Atherectomy devices with high-speed rotating blades driven by a motor are also employed to disrupt calcified plaques, creating a passage through heavily calcified occlusions that cannot be traversed by other means. These methods of optimizing the outcomes of endovascular revascularization can be used individually or in combination.We have analyzed the technical aspects of performing the mentioned procedures and their clinical outcomes based on literature sources. According to published data, the application of methods to optimize the outcomes of endovascular revascularization of infrainguinal arteries increases the success rate of these procedures to ≥90%. The widespread use of these methods is hindered by the high cost of re-entry and atherectomy devices. Accumulating our own experience will help improve the effectiveness of angioplasty in patients with chronic infrainguinal artery occlusions.

SURGICAL TREATMENT OF EARLY POSTOPERATIVE COMPLICATIONS OF ENDOVASCULAR REVASCULARIZATION OF A MULTI-LEVEL STENOTIC-OCCLUSIVE ATHEROSCLEROTIC LESION OF THE FEMORAL-DISTAL ARTERIAL BED

The use of endovascular techniques remains the only chance to restore blood flow under the conditions of a distal stenotic-occlusive process. Nevertheless, under the conditions of endovascular reconstructive surgery of the distal arterial bed, unsatisfactory results occur in 6-32% of cases in the form of thrombosis or restenosis of the reconstruction segment due to the progression of signs of limb ischemia.
 The aim is to improve the results of endovascular revascularization of multilevel atherosclerotic stenotic-occlusive femoral-distal arterial bed by surgical treatment of postoperative complicated forms of revascularized infrainguinal arterial bed.
 Materials and methods. 164 patients with multilevel stenotic-occlusive lesions of the femoral-distal arterial bed were under observation. Ultrasound dopplerography was used to select the volume of reconstructive intervention. Endovascular angioplasty of the femoral-popliteal segment (I stage) was performed with Pan Medical (PEKICO), OPTA PRO (Cordis) balloon catheters. In 41.10% of observations, balloon angioplasty of the femoral segment was continued with the placement of a stent - a self-expanding Smart ControL stent (Cordis), a self-expanding Carbostent stent (Flype), a self-expanding stent - Vascular stent (BARD) was used. Endovascular angioplasty of the arteries of the tibial segment (II stage) was performed using long balloons (80-150 mm) Armada 35 LL manufactured by Abbott Vascular (USA) and Amphirion Deep (Medtronic) Coyote (Boston Scientific). 76 intraluminal and 33 subintimal angioplasty were performed. When performing subintimal angioplasty, CompleteSE (Medtronic), Smart (Cordis) and CompleteSE (Medtronic) stents were used. In 40 patients, angioplasty was performed on two arteries of the leg, in 33 - on one of the tibial arteries. At the first stage, an open reconstruction of the femoral-popliteal segment was performed - the formation of a femoral-popliteal autovenous shunt. In 20 (21.98%) observations, the proximal anastomosis was formed at the level of the bifurcation of the thoracic cavity during simultaneous deep fundoplasty. In 36 (39.51%) observations, the distal anastomosis of the autovenous shunt was formed at the level of the PCA by the end-to-end type. A 6F Check-Flo Performer (USA), Balton (EU) introducer was used to ensure the change of the balloon catheter. Long balloons (80-150 mm) Armada 35 LL manufactured by Abbott Vascular (USA) and Amphirion Deep (Medtronic) Coyote (Boston Scientific) were used, CompleteSE stents (Medtronic) – 23 cases, Smart (Cordis) – 24 observations.
 Conclusions. The early postoperative period of endovascular revascularization of a multilevel stenotic-occlusive lesion of the femoral-distal arterial bed is complicated by thrombosis of the popliteal-tibial segment in 15.9% of observations. Thrombosis of the popliteal segment is detected 2.7 times more often after endovascular angioplasty of one of the tibial arteries during endovascular revascularization of a multilevel stenotic-occlusive lesion of the femoral-distal arterial bed than during endovascular angioplasty of two tibial arteries. The effectiveness of the use of rheological thrombus extraction by the Angiojet system in the surgical treatment of postoperative thrombosis of the popliteal segment, which is formed in 15.9% of observations after endovascular revascularization of a stenotic-occlusive lesion of the femoral-distal arterial bed, is equal to 84.6%.

Predictors of restenosis after popliteal angioplasty in patients with chronic limb threatening ischemia

Purpose: To evaluate factors associated with restenosis after angioplasty of popliteal artery lesions in patients presenting with chronic limb threatening ischemia. Methods: A prospective non-randomized study between from August 2018 to December 2020 conducted on 25 patients presenting with chronic limb threatening ischemia and having popliteal artery atherosclerotic occlusive disease (median age 65.52 (±8.35) years). Plain balloon angioplasty was done and patients were followed for 6 months. The primary outcomes were the primary patency and predictors of restenosis. Results: The primary patency at 6 months was 64%. Restenosis after angioplasty was associated with the presence of multilevel disease (p=0.036), presence of complete total occlusion (p=0.003), and subintimal angioplasty (p=0.005). Other studied variables weren't associated with patency loss. Conclusion: Angioplasty of popliteal atherosclerotic disease is feasible and has accepted short term primary patency rate. The presence of multilevel disease, popliteal complete occlusion, and the use of subintimal angioplasty were associated with lower primary patency after 6 months.

Optimal Intraluminal Drug-Coated Balloon Versus Drug-Eluting Stent in Patients With Chronic Total Occlusion of the Superficial Femoral Artery: A Retrospective Analysis

BackgroundPaclitaxel-eluting technologies improve the clinical outcome of femoropopliteal (FP) occlusive disease. Several studies reported efficacy of the high-dose (nominal paclitaxel density of 3.5 μg/mm2) drug-coated balloon (DCB) for complex FP lesions. However, previous studies of DCB have shown a high rate of bailout stents, and few studies have compared the high-dose DCB with successful lesion pre-dilation without bailout stent and drug-eluting stent (DES) in chronic total occlusion (CTO) of the superficial femoral artery (SFA). This study aimed to compare the clinical outcome of high-dose DCB with successful lesion preparation and DES in CTO of the SFA. MethodsThis was a single-center, retrospective study. From June 2018 to November 2020, we compared 41 patients (43 lesions) treated with high-dose DCB and 36 patients (37 lesions) treated with DES. The study period was defined as the period after DCB and DES became available simultaneously at our hospital, when all surviving patients had at least 1 year of follow-up. The primary endpoint was 12-month primary patency. The secondary endpoints were 12-month freedom from: (1) clinically driven target lesion revascularization (CD-TLR), and (2) re-occlusion. ResultsBaseline clinical data were comparable between the two groups. Reference vessel diameter was smaller in the DCB group. The mean lesion and occlusion lengths were about the same in both groups. The subintimal angioplasty and bailout stent rate was 0% in the DCB group. The Kaplan–Meier estimate for 12-month primary patency was 92.0% in the DCB group and 87.2% in the DES group (p = 0.47). Freedom from CD-TLR also did not differ significantly between the two groups. The 12-month freedom from re-occlusion rate tended to be higher in the DCB group than in the DES group. ConclusionsHigh-dose DCB with successful lesion preparation showed 12-month clinical outcomes comparable with DES for CTO of the SFA, even without bailout stents.

Effect of temperature-sensitive nanogel combined with angioplasty on sICAM-1 and VE-cadherin in lower extremity arterial occlusion rabbits

ABSTRACT The study was to explore the effect of subintimal angioplasty (SIA) on the levels of soluble intercellular adhesion molecule-1 (sICAM-1) and vascular endothelial cadherin (VE-cadherin) in the rabbit model of lower extremity arterial occlusion. Specifically, the poly(N-isopropylacrylamide-co-butyl methacrylate) (PIB) temperature-sensitive nanogel was prepared, and the cytotoxicity of direct and indirect contact with PIB temperature-sensitive gel was analyzed then. Subsequently, the PIB temperature-sensitive gel was injected to the New Zealand white rabbit to prepare the lower extremity arterial occlusion model. The healthy control, model group, and SIA group were compared for the serum lipids, fibrinogen (Fbg), fibrinogen (Fbg), and fibrinogen (Fbg) levels. The results showed that the cell proliferation activity and survival rate were always higher than 90% under different concentrations of PIB temperature-sensitive gels. Compared with the model group, the SIA group had increased total cholesterol (TC), triglycerides (TG), low-density lipoprotein (LDL), and Fbg levels, but decreased high-density lipoprotein (HDL) level (P < 0.05); decreased TXB2, ET-1, and ICAM-1 levels, but increased levels of 6-Keto-PGF1α and NO (P < 0.05); and decreased sICAM-1 and VE-cadherin levels (P < 0.05). It showed that PIB temperature-sensitive nanogel can elicit vascular embolism, and SIA is suggested in the treatment of lower extremity arterial occlusion.

Factors Contributing to Efficient Recanalization Procedures for Chronic Total Occlusion of the Superficial Femoral Artery

BackgroundThis study aimed to clarify the factors for efficient procedures (EP) in superficial femoral artery (SFA) chronic total occlusion (CTO). MethodsWe retrospectively analyzed 200 consecutive limbs that underwent treatment for SFA CTO. The patients were divided into three groups according to the main strategies: subintimal angioplasty (SIA) (n = 123), Crosser use (n = 50), and 0.014″ CTO guidewire (CTO-GW) (n = 27). To determine the factors for an EP (EP; contrast volume <130 mL and procedure time <20 min; derived from non-CTO [control] procedures), the variables (P < 0.2) underwent multivariate analysis. ResultsSIA included more Trans-Atlantic Inter-Society Consensus C/D lesions and contralateral femoral approaches, and additional GW use (P < 0.05). CTO-GW presented a shorter occlusion length and elapsed time, and used less retrograde approach than the other strategies (P < 0.05). Crossers had a higher incidence of perforation (P = 0.002). The prompt retrograde approach had a similar actual retrograde procedure time, but a shorter total procedure time, compared to that of the delayed adoption (P < 0.001). EP was achieved in 14 limbs (7.0%). Multivariate analysis revealed that occlusion length (adjusted odds ratio [OR], 0.89; 95% CI, 0.81–0.96; P = 0.004) and SIA (OR, 8.71; 95% CI, 1.32–175.27; P = 0.02) were associated with EP. ConclusionsSIA contributed to EP. The timing of the retrograde approach was crucial because its delay resulted in an excessive procedure time.

Endovascular revascularization of chronic total arterial occlusion of the lower limb using the SAFARI technique.

The SAFARI technique or Subintimal Arterial Flossing with Antegrade-Retrograde Intervention is an endovascular procedure that allows recanalization of Chronic Total Occlusive (CTO) lesions when conventional subintimal angioplasty is unsuccessful. Retrograde access is usually obtained through the popliteal, anterior tibial, dorsalis pedis artery, or posterior tibial arteries and may potentially provide more options for endovascular interventions in limb salvage. The case of an 81-year-old man with a history of uncontrolled hypertension, diabetes mellitus, and dyslipidemia is presented. He presented with a cutaneous ulcer on the right lower limb with torpid evolution and poor healing. The Doppler ultrasound and arteriographic study revealed a CTO lesion of the popliteal artery that was not a candidate for antegrade endovascular revascularization, but was successfully treated using the SAFARI technique. The patient had no perioperative complications, the wound showed better healing, and he was discharged with an indication of daily dressings and control by an external outpatient clinic.

Endovascular management of aorto-iliac occlusive disease (Leriche syndrome)

Bypass grafting is the standard of care for chronic aorto-iliac occlusive disease (AIOD, aka Leriche Syndrome) but is associated with mortality rates of up to 25% if surgical re-intervention is necessary. Despite a recent shift towards an endovascular-first strategy for TransAtlantic InterSociety Consensus II ("TASC II") C and D lesions, reports from Leriche Syndrome are still limited. 15 high-risk patients (11 male, 4 female), mean age of 60.6 years, with chronic aorto-iliac occlusive disease were retrospectively reviewed. Retrograde approaches via the bilateral femoral arteries for aortic occlusion less than 4cm in length and/or antegrade fashion from the brachial artery for juxtarenal type lesions were made. For the latter, thrombolysis prior to angioplasty was also performed. Intraluminal or if necessary, subintimal angioplasty was performed with deployment of either bare metal stents or stentgrafts in a kissing-stent fashion. A total of 28 iliac arteries and 14 occluded abdominal aorta were treated with 100% technical success, of which 25% success were achieved by using subintimal technique. Two minor complications occurred, including vascular rupture and distal emboli in one patient apiece, which were successfully managed via endovascular fashion. There were no complications of renal artery emboli. Primary and secondary patency rates at 1, 3 and 5 years were 92.3% and 100%; 83.9% and 100%; and 83.9% and 100%, respectively. Endovascular therapy for chronic aorto-iliac occlusion has a high technical success rate, with good short- and mid-term primary and secondary patency rates and may provide a valid alternative to surgery for high-risk patients.

Feasibility of the novel proximal superficial femoral artery puncture technique to recanalize chronic total occlusions

Chronic total occlusion (CTO) of the superficial femoral artery (SFA) with flush occlusion is sometimes difficult to be treated by endovascular treatment (EVT). The guidewire could not pass the proximal cap because the entry of the CTO could not be detected by angiography. Thus, a retrograde approach is considered; however, there was a risk of jeopardizing the adjacent deep femoral artery by subintimal angioplasty. Moreover, the retrograde approach is not feasible when the distal artery could not be punctured because of stenosis, occlusion, or uncomfortable positioning for patients during EVT. Therefore, we considered a novel technique to overcome this problem, called the Proximal superficial femoral Artery Puncture to RecanalIze the Chronic totAl occlusion (PAPRICA) technique. In this technique, to establish wire externalization, a retrograde puncture was performed from the proximal site of the SFA-CTO under ultrasound guidance, and the guidewire was advanced retrogradely from the puncture needle via the CTO site. After wire externalization, the guide catheter could be advanced into the SFA ostium. By pulling up the externalization wire, a strong backup and improved coaxial alignment of the guide catheter were achieved. This report presents two successful cases of flush SFA-CTO using this novel technique.

Modified subintimal plaque modification improving future recanalization of chronic total occlusion percutaneous coronary intervention.

BackgroundSubintimal plaque modification (SPM) is often performed to restore antegrade flow and facilitate subsequent lesion recanalization. This study aimed to compare the safety and efficacy of modified SPM with traditional SPM.MethodsA total of 1454 consecutive patients who failed a chronic total occlusion percutaneous coronary intervention (CTO PCI) attempt and underwent SPM from January 2015 to December 2019 at our hospital were reviewed retrospectively. Fifty-four patients who underwent SPM finally were included in this study. We analyzed the outcomes of all the patients, and the primary endpoint was recanalization rate, which was defined as Thrombolysis in Myocardial Infarction (TIMI) grades 2-3 flow on angiography 30 to 90 days post-procedure.ResultsThe baseline characteristics were similar between the two groups. In the follow-up, the recanalization rate was noticeably higher in the modified SPM group compared with the traditional SPM group (90.9% vs. 62.5%, P < 0.05). The proposed strategy in the modified group was more aggressive, including a larger balloon size (1.83 ± 0.30 vs. 2.48 ± 0.26 mm, P < 0.05) and longer subintimal angioplasty (0.59 ± 0.16 vs. 0.92 ± 0.12 mm, P < 0.05). Also, the common use of a Stingray balloon and guide catheter extension resulted in improvement of patients in the modified SMP group (12.5% vs. 100%, P < 0.05).ConclusionModified SPM, which is associated with a high likelihood of successful recanalization, is an effective and safe CTO PCI bail out strategy.

Editor's Choice – Impact of Endovascular Pedal Artery Revascularisation on Wound Healing in Patients With Critical Limb Ischaemia

The present study investigated the impact of endovascular pedal artery revascularisation (PAR) on the clinical outcomes of patients with critical limb ischaemia (CLI). This retrospective analysis of a single centre cohort included 239 patients who underwent endovascular revascularisation of infrapopliteal arteries for a chronic ischaemic wound. PAR was attempted in 141 patients during the procedure. After propensity score matching, there were 87 pairs of patients with and without PAR. After the matching, the two groups showed balanced baseline clinical and lesion characteristics. PAR was achieved in 60.9% of the PAR group. Direct angiosome flow was more frequently obtained in the PAR group than in the non-PAR group (81.6% vs. 34.5%; p<.001). Subintimal angioplasty (47.1% vs. 29.9%; p=.019) and pedal-plantar loop technique (18.4% vs. 0%; p<.001) were more frequent in the PAR group. At the one year follow up, the PAR group showed greater freedom from major amputation (96.3% vs. 84.2%; p=.009). The wound healing rate, overall survival, major adverse limb event, and freedom from re-intervention did not differ significantly between the two groups. However, the patient subgroup with successful PAR showed a higher wound healing rate than the non-PAR group (76.0% vs. 67.0%; p=.031). In a multivariable Cox proportional hazards regression model, successful PAR (hazard ratio [HR] 1.564, 95% confidence interval [CI] 1.068-2.290; p=.022) was identified as an independent factor associated with improved wound healing, whereas gangrene (HR 0.659, 95% confidence interval [CI] 0.471-0.923; p=.015), C reactive protein >3mg/dL (HR 0.591, 95% CI 0.386-0.904; p=.015), and pre-procedural absence of pedal arch (HR 0.628, 95% CI 0.431-0.916; p=.016) were associated with impaired wound healing. Successful PAR significantly improved wound healing in patients with CLI. Thus, efforts should be made to revascularise the pedal arteries, especially when the pedal arch is completely absent.

Use, Safety and Effectiveness of Subintimal Angioplasty and Re-Entry Devices for the Treatment of Iliac Artery Chronic Total Occlusions: A Systematic Review of 30 Studies and 1112 Lesions

Management of iliac artery occlusive disease has changed dramatically over the past few decades. Secondary to advancement in endovascular technologies and techniques, percutaneous interventions have gradually replaced open surgical approaches even for the most difficult cases. In difficult to cross chronic total occlusions (CTO) of the iliac artery, subintimal angioplasty (SIA) with or without the use of re-entry devices (RED) offers a valuable alternative to intra-luminal crossing. To systematically review the literature for studies reporting procedural or short- and long-term clinical outcomes after the use of SIA, with or without RED use for iliac CTOs. PRISMA guidelines were followed. Literature search (PubMed, Cochrane CENTRAL and EMBASE) and data extraction were performed by two independent researchers. Quantitative synthesis of the reported outcomes was applied when possible. Thirty studies met the inclusion criteria and were selected as eligible for this systematic review, with a total of 1002 patients (61.3% males) and 1112 lesions treated with SIA. RED were used in 21.9% of the lesions. Critical limb ischemia was the indication in 51.4%. The overall procedural success rates were 85.8% for SIA and 88.5% for RED. The complication rate ranged from 0 to 10% among different series, but overall it was similar among the two groups (6.9% in the RED group and 6.7% among the SIA group). One year primary patency rates were around 60% in the RED. In the SIA only arm, there was a large heterogeneity, with patency rates ranging from 51.7% to 96.8%. SIA with or without RED use is a safe and effective treatment for the treatment of iliac artery CTOs. Future studies are needed to delineate whether intraluminal crossing or SIA is more effective for endovascular treatment of iliac CTOs.

Use, Safety and Effectiveness of Subintimal Angioplasty and Re-Entry Devices for the Treatment of Femoropopliteal Chronic Total Occlusions: A Systematic Review of 87 Studies and 4,665 Patients.

Subintimal angioplasty (SIA) is often utilized to cross femoropopliteal (FP) artery chronic total occlusions (CTOs). Re-entry devices (RED) can further assist with true lumen re-entry. To systematically review the literature for studies reporting on the use of SIA, with or without RED. A systematic review according to the PRISMA guidelines was performed. Quantitative synthesis was applied when possible. 87 studies and 4665 patients (5161 lesions) were included (63.9% male). 46.7% of patients had critical limb ischemia at the time of the intervention. Two RED types were used (Pioneer and Outback). Sixty-eight studies included lesions treated with SIA without RED, 17 studies included lesions treated with RED only, and two studies included a comparison between the two treatment methods. In total, 3898 (83.6%) patients were treated with SIA without RED and 754 (12.2%) with RED. Procedural success rate ranged from 64.5%-100% (92.5% for SIA without RED, 88.3% for RED cases). The complication rate ranged from 1.6% - 28% among different studies (cumulative rates: SIA: 9.1%, RED 9.3%). Perforations occurred in 1.6% of the total population (n = 46). Primary patency at one year ranged from 22% to 94.1%. Newer studies had a higher patency rate, ranging from 70% to 94.1%. SIA with or without RED is a valuable alternative to intraluminal crossing for endovascular treatment of FP CTOs. Procedural success was excellent for both techniques, while the cumulative complication rate was numerically lower in the RED group. Short- and long-term outcomes were acceptable for both techniques.

FEM Simulation of Subintimal Angioplasty for the Treatment of Chronic Total Occlusions

Subintimal angioplasty is a highly challenging technique for percutaneous treatment of chronic total occlusion (CTO) in blood vessels, and the development of predictive tools for preliminary evaluation of potential outcomes and risks could be very useful for clinicians. While finite element (FE) simulation is a well-established approach to investigating partial occlusions, its extension to CTO has not been investigated yet, because of several additional issues that have to be addressed. In this work, we discuss the implementation of a FE model to simulate the main steps of the procedure, i.e., subintimal insertion of an initially folded balloon in a false lumen, inflation from eccentric position, deflation, and extraction. The model includes key morphological features of the CTO and possibility of varying spatial distribution of material properties to account for different constituents and degree of calcification. Both homogeneous and heterogeneous CTO configurations were analyzed, comparing arterial stress state, plaque compression, and postprocedural recoil. For a peak inflation pressure of 12 bar, the degree of lumen restoration was in the range 65-80%, depending on plaque heterogeneity. After balloon extraction, homogeneous highly calcified plaques exhibited substantial recovery of original shape. For homogeneous and heterogeneous CTO, values of peak von Mises stress in the arterial wall were of the same order of magnitude (range 1-1.1 MPa) but at different locations. Results compared favorably with data reported in literature for postprocedural lumen restoration and arterial stress data, confirming potential usefulness of the approach.

Endovascular invasions for femoral-popliteal segment disorders of C andD-type according to TASC-II classification

Currently, direct re-vascularization for the management of critical limb ischemia (CLI) is effectuated through open and hybrid surgical treatments. At the same time, therapeutic recommendations for one of the methods appear as a subject of lasting discussions. Today TASC II (TransAtlantic Inter-Society Consensus for the Management of Peripheral Arterial Disease) adopted in 2007 is the most popular document that provides justifications for endovascular and surgical treatment of peripheral arterial disease. Clinical practice provides evidence that there is a significant number of patients having critical limb ischemia who suffer from vascular bed disorders and are classified as C or D-type according to TASC classification. Meanwhile, there also are cases when these patients have no other alternative than re-vascularization by means of open surgery, which is why endovascular invasion appears as the only method of re-vascularization for them. The article presents some results of comparative studies within endovascular and surgical tools aimed at revascularization in the area of femoral-popliteal segment, including cases where patients are classified as C and D-type. The results of shunting operations are compared to angioplasty and remote endarterectomy, whereas technical methods for re-entry during subintimal angioplasty are regarded apart. Despite the fact that there are medical recommendations for the use of endovascular and surgical methods depending on TASC II classification, today there is no evidence that these tools can be efficient in revascularization of femoral-popliteal segment. In order to identify the efficiency of distinct methods in revascularization of femoral-popliteal segment there a need in a number of extended randomized studies designed to evaluate the role of such factors, as anatomic location of the vascular bed disorder, the extent of a disease, the location of purolo-necrotic areas as well as other pathologies on the results of the study.

Initial Experience With the Outback Catheter for Targeted Reentry During Subintimal Angioplasty of the Infragenicular Arteries

Purpose: To report use of the Outback reentry device for targeted distal reentry during subintimal recanalization of chronic total occlusions (CTOs) in the infragenicular arteries. Methods: During an 18-month period, the Outback device was applied in 10 patients (mean age 71.8±18.8 years; 8 men) to achieve reentry at the infragenicular segment following either unsuccessful spontaneous reentry after subintimal crossing of a CTO or when a targeted reentry was desired. The mean occlusion length was 117.5±101.0 mm. Technical (device) success, overall procedure success, and reentry accuracy are reported, along with any major or minor complications. Results: The device was technically successful in achieving reentry in 9 of 10 cases; overall procedure success was achieved in 8 owing to heavy calcifications in a distal posterior tibial artery and a distal popliteal artery. The reentry accuracy was 10.8±14.6 mm. There were no major complications and only 3 minor sequelae, including 2 dissections and 1 small perforation; all were treated successfully with stenting. Conclusion: The Outback device has a high technical success rate in achieving targeted true lumen reentry in infragenicular subintimal angioplasty when spontaneous reentry is not possible or a targeted reentry is desirable.

SFA Intervention: Intraluminal or Subintimal?

Subintimal angioplasty (SA) is an endovascular technique to recanalize an occluded arterial segment through an extraluminal channel between the intima and media. Since its introduction in 1989, the technical success rate has improved with the accumulation of procedural experience and the development of retrograde approaches and re-entry devices. To date, no randomized trial has compared SA with intraluminal angioplasty (IA) for chronic total occlusion (CTO) of the superficial femoral artery (SFA). Based on limited data from several registry studies, SA appears to achieve a higher technical success rate than IA, whereas mid-term primary patency rates are comparable for both endovascular wiring strategies for SFA CTO. Additional clinical data are needed to confirm that SA is as effective as IA. The optimal stenting strategy and role of drug-eluting technologies also need to be defined to improve SA outcomes.