Long-Term Outcome following Stent Reconstruction of the Aortic Bifurcation and the Role of Geometric Determinants

Covered endovascular reconstruction of the aortic bifurcation: A systematic review aggregated data and individual participant data meta-analysis

BACKGROUND

We investigated the early and midterm efficacy and safety of covered endovascular reconstruction of the aortic bifurcation (CERAB) in the treatment of aortoiliac disease (AID).

METHODS

A systematic search on PubMed, Scopus, and Web of Science for articles published by August 2023 was performed. The primary end points were primary patency and secondary patency.

RESULTS

Eleven retrospective case series, involving 579 patients, were incorporated in the review with 88.9% of the included lesions being categorized as Trans-Atlantic Inter-Society Consensus (TASC) C or D. The pooled primary patency estimates at 12, 24 and 36 months were 94.4% (95% confidence interval [CI], 89.4-99.7), 84.4% (95% CI, 72.3-98.5) and 83.8% (95% CI, 71.4-98.3) respectively. The mean primary patency time, representing the period during which individuals remained event-free, was 51.9 months (95% CI, 43.6-55.4). The pooled 36 months primary patency for studies with a predominantly claudicant patient population (>75% of patients) was 89.4% (95% CI, 78.5-100.0), compared with 71.5% (95% CI, 45.6-100.0) for studies with a mixed population (50% of patients). The pooled 36 months primary patency for studies with a predominantly TASC D patient population (>82% of patients) was 70.4% (95% CI, 46.4-100.0) compared with 91.0% (95% CI, 79.1-100.0) for studies with a more homogenous cohort. The pooled secondary patency estimates at 12, 24, and 36 months were 98.6% (95% CI, 96.2-100.0), 97% (95% CI, 93.1-100.0), and 97% (95% CI, 93.1-100.0), respectively. The pooled technical success, 30-day mortality and 30-day systemic complications estimates were 95.9% (95% CI, 93.7- 97.4), 1.9% (95% CI, 1.0-3.5), and 6.4% (95% CI, 4.4-9.1), respectively. The pooled intraoperative and postoperative 30-day CERAB-related complications estimates were 7.3% (95% CI, 2.0-23.0) and 4.2% (95% CI, 0.7-21.0), respectively. The pooled major amputation and target lesion reinterventions by the end of follow-up were 1.9% (95% CI, 1.0-3.4) and 13.9% (95% CI, 9.9-19.2), respectively. The pooled access site complication estimate was 11.7% (95% CI, 5.9-21.7).

CONCLUSIONS

Although this review has showcased the safety and feasibility of the CERAB technique in treating AID, it has also highlighted the necessity for a close and prolonged follow-up period extending beyond 1 year. Moreover, the favorable secondary patency estimates predominantly attained via endovascular reinterventions emphasize a potentially advantageous characteristic of the CERAB technique, particularly valuable when addressing late-stage AID disease or anatomically complex lesions.

Comparative Analysis of Outcomes of Unibody Endoprosthesis and Aortobifemoral Bypass for Aortoiliac Occlusive Disease

BACKGROUND

Aortoiliac occlusive disease (AIOD) has traditionally been treated with aortobifemoral bypass (ABF). Unibody endograft (UBE) for AIOD, however, has been increasingly utilized in selected patients. We report outcomes of patients undergoing ABF or UBE for AIOD.

METHODS

Patients (2016-2021) undergoing elective ABF or UBE with a unibody device for AIOD were identified at an academic institution. Chi-square and Kaplan-Meier analysis were used to evaluate outcomes by group.

RESULTS

One hundred thirty-one patients undergoing UBE or ABF were screened, with 82 included. Twenty-one patients underwent UBE (25.6%) and 61 (74.4%) underwent ABF. UBE patients were older (63.8 vs. 58.2 years; P = 0.01), with a higher prevalence of diabetes (52.4 vs. 19.7%; P = 0.004). Significant differences were seen between UBE and ABF including a shorter surgery length (214 vs. 360 min; P = 0.0001), less blood loss (300 vs. 620 mls; P = 0.001), larger minimum aortic diameter (14.6 vs. 12.6; P = 0.0006), larger common iliac artery (9.5 vs. 7.9; P = 0.005) and lower postoperative ankle-brachial index (0.8 vs. 0.9; P = 0.04). There were no differences in TASC C/D iliac lesions in the UBE than ABF group (66.6% vs. 63.9%; P < 0.82) or Trans-Atlantic Inter-Society Consensus classification femoropopliteal lesions. Unadjusted analysis revealed no significant differences between UBE and ABF for 30-day mortality (0 vs. 1.6%; P = 1), stroke (0 vs. 3.3%; P = 1), or major adverse cardiac events (4.8 vs. 4.9%; P = 1). There were no significant differences in mid-term surgical outcomes over a mean follow-up period of 23.7 months between UBE and ABF groups; specifically endovascular (0 vs. 8.2%; P = 0.3) or open/hybrid reintervention (9.5 vs. 14.8%; P = 0.7) with similar limb occlusion (4.8 vs. 27.8; P = 0.12). Kaplan-Meier estimated primary, primary-assisted, and secondary patency at 36 months were similar with 94%, 100%, and 94% for UBE and 86%, 95%, and 86% for ABF, respectively. Estimated survival at 36 months was 95% for UBE and 97% for ABF (P = 0.8).

CONCLUSIONS

Equivalent outcomes were seen between AIOD treated with UBE or ABF in similar patient populations. Mid-term outcomes such as reintervention and patency are similar for UBE and ABF. We still recommend ABF over UBE as a primary modality of treatment in surgically fit patients with greater complexity aortoiliac lesions and with smaller arterial diameters, especially women.

Aortobifemoral bypass vs covered endovascular reconstruction of aortic bifurcation

BACKGROUND

Covered endovascular reconstruction of aortic bifurcation (CERAB) is increasingly used as a first line-treatment in patients with aortoiliac occlusive disease (AIOD). We sought to compare the outcomes of patients who underwent CERAB compared with the gold standard of aortobifemoral bypass (ABF).

METHODS

The Vascular Quality Initiative was queried for patients who underwent ABF or CERAB from 2009 to 2021. Propensity scores were generated using demographics, comorbidities, Rutherford class, and urgency. The two groups were matched using 5-to-1 nearest-neighbor match. Our primary outcomes were 1-year estimates of primary patency, major adverse limb events (MALEs), MALE-free survival, reintervention-free survival, and amputation-free survival. Standard statistical methods were used.

RESULTS

A total of 3944 ABF and 281 CERAB cases were identified. Of all patients with AIOD, the proportion of CERAB increased from 0% to 17.9% between 2009 and 2021. Compared with ABF, patients who underwent CERAB were more likely to be older (64.7 vs 60.2; P < .001) and more often had diabetes (40.9% vs 24.1%; P < .001) and end-stage renal disease (1.1% vs 0.3%; P = .03). In the matched analysis (229 CERAB vs 929 ABF), ABF patients had improved MALE-free survival (93.2% [±0.9%] vs 83.2% [±3%]; P < .001) and lower rates of MALE (5.2% [±0.9%] vs 14.1% [±3%]; P < .001), with comparable primary patency rates (98.3% [±0.3%] vs 96.6% [±1%]; P = .6) and amputation-free survival (99.3% [±0.3%] vs 99.4% [±0.6%]; P = .9). Patients in the CERAB group had significantly lower reintervention-free survival (62.5% [±6%] vs 92.9% [±0.9%]; P < .001). Matched analysis also revealed shorter length of stay (1 vs 7 days; P < .001), as well as lower pulmonary (1.2% vs 6.6%; P = .01), renal (1.8% vs 10%; P < .001), and cardiac (1.8% vs 12.8%; P < .001) complications among CERAB patients.

CONCLUSIONS

CERAB had lower perioperative morbidity compared with ABF with a similar primary patency 1-year estimates. However, patients who underwent CERAB experienced more major adverse limb events and reinterventions. Although CERAB is an effective treatment for patients with AIOD, further studies are needed to determine the long-term outcomes of CERAB compared with the established durability of ABF and further define the role of CEARB in the treatment of AIOD.

Combination of BeGraft and Solaris Stent Grafts for the Covered Endovascular Reconstruction of Aortic Bifurcation-BS-CERAB Technique

Background: This study examines the impact of the use of the combination of BeGraft and Solaris stent grafts on the outcomes during the covered endovascular reconstruction of aortic bifurcation (BS-CERAB) technique and extension to the iliac arteries. Methods: Consecutive patients with aortoiliac occlusive disease who underwent endovascular treatment using BS-CERAB between January 2020 and December 2023 were included. Patient demographics, symptoms, lesion characteristics, and procedural and follow-up details were collected and analyzed. Perioperative complications and reinterventions were also identified. Results: A total of 42 patients met the inclusion criteria (32 men, 76.2%, median age 72 years, range 59-85). Indications for treatment were intermittent claudication (42.9%) and critical limb ischemia (57.1%). Procedure success was achieved in all cases. The median patient follow-up time was 14 months (1-36). One patient died at a 10-month follow-up due to lung cancer. The mean pre-operative ABI increased from 0.37 ± 0.19 before intervention to 0.71 ± 1.23 post-operatively at 12 months (p = 0.037). The estimated primary patency rates at 3, 6, and 12 months were 90.5%, 85.7%, and 81.0% and primary assisted patency rates were 90.5%, 90.5%, and 85.7%, respectively. Secondary patency was 95.2% at 3 and 6 months and 90.5% at a 12-month follow-up. Active cancer (p = 0.023, OR 2.12 95%CI 1.14-3.25) was a risk factor for restenosis. Conclusions: This mid-term experience shows that the CERAB technique using the combination of BeGraft and Solaris stents grafts, for the endovascular treatment of severe aortoiliac atherosclerotic disease, may allow an effective reconstruction of the aortic bifurcation and iliac arteries related to high-patency and lower-reintervention rates.

Role of intravascular ultrasound for the technical assessment of endovascular reconstruction of the aortic bifurcation

OBJECTIVE

The aim of this study was to evaluate the role of intravascular ultrasound (IVUS) for the technical assessment of kissing stents (KSs) and covered endovascular reconstruction of the aortic bifurcation (CERAB) in the treatment of aortoiliac obstructive disease involving the aortic bifurcation.

METHODS

We conducted a single-center retrospective review of patients undergoing endovascular treatment of severe aorto-iliac obstructive disease (2019-2023). IVUS was performed in patients treated by KSs or CERAB according to preoperative indications, in cases of moderate/severe calcifications, mural thrombus, total occlusions, and lesion extension towards the proximity of renal or hypogastric arteries. Indications for IVUS-guided intraoperative revisions were residual stenosis or compression >30%, incomplete stent-to-wall apposition, or flow-limiting dissection at the landing site. Follow-up assessment was performed at 6 and 12 months, and then yearly. Thirty-day outcomes and 2-year patency rates were evaluated. Logistic regression was used to identify factors associated with significant technical defects detected by IVUS needing intraoperative revision.

RESULTS

IVUS was used for the technical assessment of 102 patients treated by KSs (n = 57; 56%) or CERAB (n = 45; 44%) presenting with severe intermittent claudication (39%), rest pain (39%), or ischemic tissue loss (25%). Twenty-nine significant technical defects were identified by IVUS in 25 patients (25%) who then had successful intraoperative correction by additional ballooning (n = 23; 80%) or stenting (n = 6; 20%). Patients with a severely calcified chronic total occlusion (odds ratio, 1.85; 95% confidence interval, 1.01-5.27; P = .044) or severely calcified narrow aortic bifurcation with <12 mm diameter (odds ratio, 2.34; 95% confidence interval, 1.10-8.64; P = .032) were at increased risk for IVUS-guided intraoperative revision. There were no postoperative deaths and no major adverse events. Two-year primary patency was 100%.

CONCLUSIONS

IVUS was used for the technical assessment of KSs/CERAB in a selected cohort of patients with severe aorto-iliac obstructive disease. This allowed the identification and intraoperative correction of a significant technical defect not detected by completion angiogram in one-quarter of patients, achieving optimal 2-year results. IVUS assessment of KSs/CERAB may be considered especially in patients with a calcified total occlusion or narrow aortic bifurcation.

Mid-term Results of Endovascular Reconstruction of Aortic Bifurcation Using COVERA Stent Graft

INTRODUCTION

This article aims to evaluate the short-term and mid-term performance of a self-expanding covered stent (COVERA Plus, Bard Tempe, Arizona) during the treatment of Trans-Atlantic Inter-Society Consensus (TASC) C/D aortoiliac obstructive lesions involving the aortic bifurcation.

METHODS

A single-center retrospective review of all patients who underwent endovascular reconstruction of the aortoiliac bifurcation for obstructive disease, with the use of Covera, from January 2018 to March 2023. All patients received a postoperative CTA (computed tomography angiography) scan within 1 month from the intervention. Precision of deployment, stent conformation, and stent symmetry were evaluated at the arterial phase of the CTA. Early outcomes were technical success and freedom from open aortic reintervention and/or mortality. Late outcomes were primary and assisted primary patency rates and freedom from reintervention.

RESULTS

During the study period, 35 patients underwent primary endovascular treatment of obstructive lesions involving the aortic bifurcation with parallel COVERA stents. Aortoiliac lesions were classified as TASC-IIC in 23 (65.7%) patients and TASC D in 12 (34.2%). Median follow-up was 49 months (interquartile [IQR]: 18-60). Overall survival was 97.1% (95% confidence interval [CI]=91-100) at 60 months. During follow-up, there were one early stent stenosis, treated with an angioplasty and stent relining with an estimated primary patency at 60 months of 97.1% (95% CI=94-100) and a primary-assisted patency of 100%. Estimated freedom from all types of reinterventions at 60 months was 94.3% (95% CI=89-99.3).

CONCLUSIONS

The new self-expanding covered Bard COVERA Plus stent used for endovascular treatment of TASC C/D aorto iliac disease proved to be safe and feasible with high technical procedural success rates. Comparison with other types of stents is necessary to further assess the role of the COVERA Plus stent in aortic bifurcation repair.

CLINICAL IMPACT

This study investigates the safety and feasibility of the new self-expanding covered Bard Covera Plus stent used for endovascular treatment of TASC C/D aorto iliac disease. The retrospective analysis of 35 patients highlights high technical success and primary patency rate at 60 months. The geometric analysis also helped to underline how this stent can be used precisely in particular conditions. These findings suggest the need for further research to compare COVERA with other types of stents in aortic bifurcation repair.

Single access covered endovascular reconstruction of the aortic bifurcation

We describe the feasibility of covered endovascular reconstruction of the aortic bifurcation (CERAB) through a single femoral access and a steerable sheath. We present the technique, which we used for a patient with severe aortoiliac calcification and bilateral involvement of the common femoral artery. The patient underwent endarterectomy of the left common femoral artery plus CERAB with an aortic stent graft and bilateral covered stents for the common iliac artery with kissing dilatation with a steerable sheath using only left femoral access. CERAB can be performed using unilateral access with the aid of a steerable sheath, reducing the potential for access site complications.

Midterm Outcomes of Kissing Covered Self-Expanding Stents for Reconstruction of Complex Aortoiliac Occlusive Disease

BACKGROUND

We sought to investigate the midterm results of kissing self-expanding covered stents (SECSs) for the reconstruction of aortic bifurcation in complex aortoiliac occlusive disease.

METHODS

Data of consecutive patients who had undergone endovascular treatment for aortoiliac occlusive disease were screened. Only patients with TransAtlantic Inter-Society Consensus (TASC) class C and D lesions treated by bilateral iliac kissing stents (KSs) were included. Midterm primary patency, risk factors, and limb salvage rates were analyzed. Follow-up results were analyzed using the Kaplan-Meier curves. Cox proportional hazards models were used to identify the predictors of primary patency.

RESULTS

A total of 48 patients (95.8% men; mean age, 65.3 ± 10.2 years) were treated with kissing SECSs. Of them, 17 patients had TASC-II class C lesions and 31 had class D lesions. There were 38 total occlusive lesions, with a mean occlusive lesion length of 108.2 ± 57.3 mm. The overall mean lesion length was 140.3 ± 60.5 mm, and the mean length of implanted stents in the aortoiliac arteries was 141.9 ± 59.9 mm. The mean diameter of the deployed SECSs was 7.8 ± 0.5 mm. The mean follow-up time was 36.5 ± 15.8 months, and the follow-up rate was 95.8%. At 36 months, the overall primary patency, assisted primary patency, secondary patency, and limb salvage rates were 92.2%, 95.7%, 97.8%, and 100%, respectively. Univariate Cox regression analysis revealed that stent diameter ≤7 mm (hazard ratio [HR]: 9.53; 95% confidence interval [CI] 1.56-57.94, P = 0.014) and severe calcification (HR: 12.66; 95% CI 2.04-78.45, P = 0.006) were significantly associated with restenosis. Multivariate analysis showed severe calcification to be the only significant determinant of restenosis (HR: 12.66; 95% CI 2.04-78.45, P = 0.006).

CONCLUSIONS

Kissing SECSs provide good midterm results for the treatment of aortoiliac occlusive disease. A stent diameter >7 mm is a potent protective factor against restenosis. Because severe calcification appears to be the only significant determinant of restenosis, patients with severe calcification require close follow-up.

Blood Flow Quantification with High-Frame-Rate, Contrast-Enhanced Ultrasound Velocimetry in Stented Aortoiliac Arteries: In Vivo Feasibility

Local flow patterns influence stent patency, while blood flow quantification in stents is challenging. The aim of this study was to investigate the feasibility of 2-D blood flow quantification using high-frame-rate, contrast-enhanced ultrasound (HFR-CEUS) and particle image velocimetry (PIV), or echoPIV, in patients with aortoiliac stents. HFR-CEUS measurements were performed at 129 locations in 62 patients. Two-dimensional blood flow velocity fields were obtained using echoPIV. Visual inspection was performed by five observers to evaluate feasibility. The contrast-to-background ratio and average vector correlation were calculated and compared between stented and native vessel segments. Flow quantification with echoPIV was feasible in 128 of 129 locations (99%), with optimal quantification in 40 of 129 locations (31%). Partial quantification was achieved in 88 of 129 locations (68%), where one or multiple limiting issues occurred (not related to the stent) including loss of correlation during systole (57/129), short vessel segments (20/129), loss of contrast during diastole (20/129) and shadow regions (20/129). The contrast-to-background ratio and vector correlation were lower downstream in the imaged blood vessel, independent of the location of the stent. In conclusion, echoPIV was feasible in stents placed in the aortoiliac region, and the stents did not adversely affect flow tracking.

Comparison of Aortobifemoral Bypass to Aortoiliac Stenting with Bifurcation Reconstruction for TASC II D Aortoiliac Occlusive Disease

OBJECTIVES

Long-segment stenting of the infrarenal aorta and bilateral iliac arteries, with or without femoral endarterectomy for diffuse disease, has been adopted for treatment of severe aortoiliac occlusive disease (AIOD). The objective of this study was to compare outcomes of this reconstruction, termed aortoiliac stenting with bifurcation reconstruction (AISBR), to aortobifemoral bypass (ABF) in patients with comparable TASC II D lesions.

METHODS

This is a single-center, retrospective review of patients treated with ABF or AISBR for comparable TASC II D lesions between 2010 and 2018. ABF patients were included only if they were deemed anatomic candidates also for AISBR after review of preoperative imaging. Patients treated for acute limb ischemia and bypass graft infection were excluded. Statistics included Fisher exact test, Kaplan-Meier analysis, and Cox proportional hazards regression.

RESULTS

There were 24 ABF and 75 AISBR included in the study. The primary indication for treatment was claudication in 55 (55.6%) patients, rest pain in 28 (28.3%), and tissue loss in 16 (16.2%). Patients undergoing AISBR were more likely to be female. Femoral endarterectomies were performed in 37/75 (49.3%) AISBR and 14/24 (58.3%) ABF (p=0.44). AISBR were performed percutaneously in 34/75 (45.1%). No AISBR required conversion to ABF. Intraoperative blood loss, procedure time and hospital length of stay (LOS) were significantly less for AISBR compared to ABF. Surgical site infections (SSI) were less common in patients undergoing AISBR (AISBR: 6/75 (8.0%) vs. ABF: 9/24 (37.5%), (p<0.01). One AISBR and two ABF developed late SSI >30 days postoperatively. The reductions in blood loss, LOS and SSI remained significant after excluding percutaneous AISBR from the analysis. Five-year primary patency was 50.8% (95% CI: 33.3, 68.4%) for AISBR and 88.1% (72.7, 100.0%) for ABF (p=0.04). Five-year survival was 76.5% (95% CI: 63.6, 89.5) for AISBR and 100% (95% CI: 100.0, 100.0) for ABF (p = 0.07). Five-year primary assisted patency, secondary patency, freedom from reintervention and major adverse limb events did not differ significantly between groups.

CONCLUSIONS

AISBR is a viable option for management of TASC II D AIOD, with lower morbidity and acceptable durability when compared to traditional ABF.

Two-year single centre results with covered endovascular reconstruction of aortic bifurcation (CERAB) in the treatment of extensive aorto-iliac occlusive disease

OBJECTIVE

To report the results of a single-centre in the treatment of extensive aorto-iliac occlusive disease (AIOD) by the covered endovascular reconstruction of aortic bifurcation (CERAB) technique.

METHODS

A retrospective analysis was conducted on data obtained from the review of medical charts of all consecutive patients treated with CERAB technique for AIOD between January 2016 and December 2019 in San Giovanni-Addolorata Hospital (Rome, Italy). Clinical examination, duplex ultrasound with ankle-brachial index measurement and contrast-enhanced computed tomography angiography were performed preoperatively. A clinical and ultrasound follow-up was carried out at one month and then half yearly after the intervention to evaluate patients' clinical status, limb salvage, target lesion revascularization rate, primary and secondary patency rate.

RESULTS

During the study period, 24 patients (14 men, 58.3%; 10 women, 41.7%; median age 59 years, range 37-79 years) underwent CERAB for AIOD (TASC II C 29.2%, TASC II D 70.8%). Indications for treatment were: intermittent claudication in 18 patients (75%) and critical limb ischemia in 6 (25%). Technical success was achieved in all cases. Perioperative minor complications occurred in three cases (12.5%). One patient reported an intraoperative iliac rupture requiring adjunctive covered stenting. Median hospital length of stay was two days (range 1-9). No patient died perioperatively nor at the last follow-up. At a median follow-up of 18 months (range 6-48 months), mean ankle-brachial index increased significantly (from 0.62 ± 0.15 before the procedure to 0.84 ± 0.18) (P < 0.001) and target lesion revascularization rate was 12.5%. At two years, the limb salvage rate was 100%, and primary and secondary patency rates were 87.5% and 100%, respectively.

CONCLUSION

CERAB technique demonstrated to be effective at the mid-term follow-up with low rate of complications and short length of stay. Long-term results and more robust data are needed to affirm this technique as the first-line treatment for extensive AIOD. However, it could become the preferred option especially in fragile patients and during contemporary COVID-19 pandemic due to the current limitations in vascular and critical care bed capacity.

Blood Flow Quantification in Peripheral Arterial Disease: Emerging Diagnostic Techniques in Vascular Surgery

The assessment of local blood flow patterns in patients with peripheral arterial disease is clinically relevant, since these patterns are related to atherosclerotic disease progression and loss of patency in stents placed in peripheral arteries, through mechanisms such as recirculating flow and low wall shear stress (WSS). However, imaging of vascular flow in these patients is technically challenging due to the often complex flow patterns that occur near atherosclerotic lesions. While several flow quantification techniques have been developed that could improve the outcomes of vascular interventions, accurate 2D or 3D blood flow quantification is not yet used in clinical practice. This article provides an overview of several important topics that concern the quantification of blood flow in patients with peripheral arterial disease. The hemodynamic mechanisms involved in the development of atherosclerosis and the current clinical practice in the diagnosis of this disease are discussed, showing the unmet need for improved and validated flow quantification techniques in daily clinical practice. This discussion is followed by a showcase of state-of-the-art blood flow quantification techniques and how these could be used before, during and after treatment of stenotic lesions to improve clinical outcomes. These techniques include novel ultrasound-based methods, Phase-Contrast Magnetic Resonance Imaging (PC-MRI) and Computational Fluid Dynamics (CFD). The last section discusses future perspectives, with advanced (hybrid) imaging techniques and artificial intelligence, including the implementation of these techniques in clinical practice.

Blood Flow Quantification in Peripheral Arterial Disease: Emerging Diagnostic Techniques in Vascular Surgery

The assessment of local blood flow patterns in patients with peripheral arterial disease is clinically relevant, since these patterns are related to atherosclerotic disease progression and loss of patency in stents placed in peripheral arteries, through mechanisms such as recirculating flow and low wall shear stress (WSS). However, imaging of vascular flow in these patients is technically challenging due to the often complex flow patterns that occur near atherosclerotic lesions. While several flow quantification techniques have been developed that could improve the outcomes of vascular interventions, accurate 2D or 3D blood flow quantification is not yet used in clinical practice. This article provides an overview of several important topics that concern the quantification of blood flow in patients with peripheral arterial disease. The hemodynamic mechanisms involved in the development of atherosclerosis and the current clinical practice in the diagnosis of this disease are discussed, showing the unmet need for improved and validated flow quantification techniques in daily clinical practice. This discussion is followed by a showcase of state-of-the-art blood flow quantification techniques and how these could be used before, during and after treatment of stenotic lesions to improve clinical outcomes. These techniques include novel ultrasound-based methods, Phase-Contrast Magnetic Resonance Imaging (PC-MRI) and Computational Fluid Dynamics (CFD). The last section discusses future perspectives, with advanced (hybrid) imaging techniques and artificial intelligence, including the implementation of these techniques in clinical practice.

[General Treatment Strategy for Intervention in Lower Extremity Arterial Disease]

The prevalence of lower extremity disease is increasing with age. With recent technological advancements, endovascular treatment is being performed more frequently. The treatment goal of intermittent claudication is to improve walking and reduce claudication. To achieve these goals, anatomical durability and patency are important. In patients with critical limb ischemia, the lesions are diffuse and particularly severe in below-the-knee arteries. The treatment goal of critical limb ischemia is to promote wound healing and to prevent major amputation, which is evaluated by the limb salvage rate. Primary stenting using covered or bare metal stents is a widely accepted endovascular treatment. While drug-eluting technologies with or without atherectomy are widely used in the treatment of femoropopliteal disease, balloon angioplasty is the mainstay treatment for below-the-knee intervention. CT angiography provides a road map for planning endovascular treatment in patients without absolute contraindications.

The Geometry of Y-Stent Configurations Used for Wide-Necked Aneurysm Treatment: Analyzing Double-Barrel Stents In Vitro Using Flat-Panel Computed Tomography

BACKGROUND

Stent-assisted coil embolization of wide-necked bifurcation aneurysms often employs a Y configuration stent. A similar stent configuration, termed kissing/double-barrel (KDB), is used often at the aortoiliac bifurcation. Studies of KDB stents in aortoiliac disease show that rates of thromboembolic complications vary with the cross-sectional geometry of the stent pair, a function of the radial crush resistive force of each stent. We assessed cross-sectional geometry of intracranial stent pairs in an in vitro model of the basilar artery using flat-panel computed tomography.

METHODS

In a silicone model of a wide-necked basilar tip aneurysm, 6 simulated KDB stent deployment trials were performed using combinations of 5 stents (Enterprise 1, Enterprise 2, Neuroform Atlas, LVIS, LVIS Jr.). Flat-panel computed tomography reconstructions were used to assess cross-sectional stent geometry. Relative conformability, defined by ovalization and D-ratio, radial crush resistive force (predicted vs. actual), and radial mismatch fraction were compared by stent type (braided vs. laser-cut).

RESULTS

Several distinct forms of cross-sectional stent geometry were observed. Braided stents had lower ovalization and D-ratio (P = 0.015) than laser-cut stents. The Neuroform Atlas/LVIS combination yielded the lowest radial mismatch fraction (19.7% vs. mean 44.3% ± 0.7%). Braided stents tended to have a deployed stent radius closer to the expected (nominal) diameter (i.e., higher relative crush resistive force) than laser-cut stents (measured vs. nominal diameter discrepancy +38.6% ± 21.1% vs. -10.7% ±16.1%, P = 0.14).

CONCLUSIONS

In constant anatomy, cross-sectional geometry of the KDB stent configuration will vary depending on the design and structure of the stents employed.

Management of Extensive Aorto-Iliac Disease: A Systematic Review and Meta-Analysis of 9319 Patients

PURPOSE

Despite advances in endovascular management of aorto-iliac occlusive disease (AIOD) including covered endovascular reconstruction of aortic bifurcation (CERAB) techniques, guidelines for management of symptomatic Trans-Atlantic Inter-Society Consensus (TASC II) type C/D lesions favour open surgical revascularisation. This meta-analysis investigates outcomes in patients with TASC II C/D lesions treated with open bypass procedures (OS), standard endovascular treatments (SEV) or CERAB.

METHODS

Multiple databases (MEDLINE, EMBASE and the Cochrane database) were searched to identify studies reporting endovascular and open treatment of extensive AIOD. Studies were independently assessed. Outcomes reported included 30-day morbidity/mortality and patency rates.

RESULTS

A total of 9319 patients undergoing intervention for extensive AIOD were identified from 66 studies. Median patient age was 64 years (n = 3204) for SEV, 58 years (n = 240) for CERAB and 59 years for OS (n = 5875). Pooled meta-analysis for 30-day morbidity in patients undergoing SEV, CERAB and OS was 9, 10 and 15%, respectively. Thirty-day mortality rate was 0.79, 0 and 3% in the SEV, CERAB and OS groups, respectively. In these groups, one-year primary and secondary patency was 90, 88, 96 and 96, 97, and 97% whilst three-year primary and secondary patency was 78, 82, 93 and 93, 97, 97% respectively. Five-year primary and secondary patency was 71 and 89% for SEV and 88 and 95% for OS, respectively. CERAB data were only available to 3 years.

CONCLUSIONS

This meta-analysis shows that thirty-day morbidity and mortality favours endovascular techniques. Primary patency remains better with OS in both early and midterms;; however, secondary patency is comparable in all groups. These findings suggest that SEV/CERAB may be considered as an alternative to OS in higher-risk patients.

Endovascular Revascularization for Aortoiliac Occlusive Disease

말초동맥질환은 하지혈관을 흔히 침범하는 폐쇄성 질환이다. 대동맥-장골동맥 부위에서 이를 치료하기 위한 재개통술은 전통적으로 수술적인 접근을 통한 우회술을 근간으로 하였으며, 최근에는 국소적이고 단순한 병변들을 위주로 혈관 내 접근법을 통한 치료법이 우선 권고되고 있다. 혈관 내 접근법은 그 최소침습적인 특성으로 인하여 수술의 위험성이 높은 환자에 대해서 활용하는 것이 일반적이었으나, 근래의 다양한 기법 및 기구의 발전으로 보다 다양한 질병 상태를 가진 환자에서 활용되어 수술적인 치료에 근접하는 결과가 보고되고 있다. 이 종설에서는 말초동맥 질환에 대한 진단 및 대동맥-장골동맥 부위의 혈관 내 재개통술에 활용되는 기법 및 기구들에 대해 살펴보고 그 역할에 대해 살펴보고자 한다.

Outcomes of Unibody Bifurcated Endograft and Aortobifemoral Bypass for Aortoiliac Occlusive Disease

Purpose

We compared the outcomes between the total endovascular approach using a unibody bifurcated aortoiliac endograft and the gold standard aortobifemoral bypass (ABF) surgery for the management of extensive aortoiliac occlusive disease (AIOD).

Methods

Materials and This retrospective observational study compared the outcomes of endovascular technique with unibody bifurcated endograft (UBE) using the Endologix AFX unibody stent-graft and a standard surgical approach (ABF) in the management of AIOD based on patient records in Western Vascular Institute, Galway University Hospital, National University of Ireland. Procedural details and outcomes were documented to compare both groups.

Results

From January 2002 to December 2018, 67 patients underwent AIOD (20 UBE and 47 ABF). Both the ABF and UBE groups showed 100% immediate clinical and technical successes without 30-day mortality. There were no statistical differences in the overall survival and sustained clinical improvement between the bypass and the UBE groups; however, statistically significant differences were observed in 3-year freedom from re-intervention and amputation-free survival. Furthermore, the mean length of the intensive care unit (ICU) stay was significantly lower in the UBE group than that in the ABF group (0.75 days vs. 3.1 days, P=0.001).

Conclusion

Total endovascular reconstruction of AIOD is an alternative to invasive bypass procedures, with a shorter ICU stay.

Treatment for aortoiliac bifurcation disease by balloon-expandable covered stent; "Double-D" molding technique

Appropriate endovascular treatment for aortic bifurcation lesions remains unclear. Incomplete apposition and radial mismatch have not been resolved to date. We treated two cases of aortic bifurcation lesions including common iliac aneurysms with balloon-expandable covered stents with "Double-D molding technique (DDMT)." This is the method. First, standard kissing stent technique with two balloon-expandable covered stents for aortic bifurcation lesions is performed. Second, either covered stent post-dilated with a larger size percutaneous transluminal angioplasty (PTA) balloon before the other covered stent also post-dilated with the same larger size PTA balloon. Kissing balloon technique was performed with the two previous size PTA balloons. Good double-D shape configuration is observed. This DDMT could improve the radial mismatch of the kissing covered stents to distal aortic wall. 〈Learning objective: The treatment of aortoiliaic bifurcation disease including iliac aneurysms with balloon expandable covered stents using "double D-shape molding technique" is safe and effective.〉.

Kissing Stent Technique for TASC C-D Lesions of Common Iliac Arteries: Clinical and Anatomical Predictors of Outcome

BACKGROUND

The endovascular treatment of peripheral artery obstructive disease in Trans-Atlantic Inter-Society (TASC) C and D lesions involving the aortic bifurcation is a matter of debate. The aim of this study is to evaluate the technical and clinical success of kissing stenting in this context and to analyze predictors of outcome.

METHODS

All patients treated for aortoiliac TASC C and D lesions with kissing stenting (from 2012 to 2017) in a 6-year period were retrospectively analyzed. Preoperative anatomical features were evaluated by reviewing computed tomography angiography images to identify severe iliac calcifications (SICs) versus not SIC (NSICs). Primary end points were as follows: technical success (TS), procedural success, primary patency (PP), and clinical success (CS). Secondary end points were as follows: secondary patency, assisted patency, survival, mid-term procedure-related complications, and risk factors that affected TS and mid-term results.

RESULTS

In a 6-year period, 51 patients fulfilled the inclusion criteria. TS was achieved in 49 (96.1%) cases. Thirty-one patients (60.8%) received a dual antiplatelet therapy (DAPT) for at least 1 month after the procedure. 30-day CS was 94.1%. Median follow-up was 45.7 months (IQR: 24.5, 8-86 range). The CS was 92.6% at 3 years, with a PP of 86.8% and a secondary patency of 93.2% at 3 years. Six (13.2%) iliac axis occluded during the first follow-up year. NSIC was statistically and independently associated with a lower PP (73% vs. 96%, P = 0.03); DAPT was statistically and independently associated with higher PP than single antiplatelet therapy (96% vs. 75%, P = 0.03); these results were confirmed by Cox regression analysis (HR: 0.14, 95%, IC: 0.01-0.89, P = 0.05 for DAPT analysis; HR: 6.8, 95%, IC: 1.21-59, P = 0.05 for NSIC analysis).

CONCLUSIONS

Endovascular treatment for TASC C-D is an effective technique. Postoperative stent occlusion is higher in patients with no DAPT and it usually occurs during the first postoperative year. Preoperative NSIC lesions are associated with reduced PP at 3 years of follow-up.

The Viabahn balloon expandable stent for endovascular reconstruction of the infrarenal aorta and its bifurcation in cases of severe obstructive disease

INTRODUCTION

The covered endovascular reconstruction of the aortic bifurcation (CERAB) represents a promising technique for the treatment obstructive lesions involving the aortic bifurcation. The aim of this report is to describe the use of a new generation balloon-expandable stent-graft (Viabahn VBX, W.L. Gore&Associates, AZ, USA), in the CERAB configuration for the treatment of aorto-iliac obstructive lesions involving the infrarenal aorta and bifurcation.Technical note: This technique was adopted in two patients with severe aorto-iliac obstructive lesions. After bilateral iliac recanalization, an 11 mm diameter VBX stent was deployed in the infrarenal aorta; a post-dilatation up to 16 mm with a non-compliant balloon was performed to adapt the proximal edge of the stent to the aortic diameter. Two 8 mm diameter VBX stents were then deployed at the aortic bifurcation in a kissing conformation, overlapping with the previously positioned aortic stent for 15 mm. A post-ballooning with two kissing 12 × 20 mm compliant balloons (Powerflex Pro PTA, Cordis, CA, USA) was performed to adapt the parallel stents to the aortic cuff. A post-operative angio-CT demonstrated optimal conformability of the aortic cuff to the aortic wall, and apposition of the kissing stents to the aortic cuff.

CONCLUSIONS

This preliminary experience shows that the VBX stent may allow an effective reconstruction of the aortic bifurcation; the conformability and flaring capability may allow to overcome the diameter mismatch between the aorta and the iliac arteries.

Update on covered endovascular reconstruction of the aortic bifurcation

Objective

The covered endovascular reconstruction of the aortic bifurcation (CERAB) technique was introduced in 2009 in order to provide an anatomically and physiologically optimal endovascular reconstruction of the aortic bifurcation.

Method

In the current review, all available evidence on this technique was summarized.

Results

In vitro studies have shown a more favorable geometry of CERAB compared to kissing stents, leading to better local flow conditions. The results of CERAB are at least as good as those achieved with kissing stents in a more complex group of treated patients. The mid-term patency rates approach those of surgical reconstruction. Initial data show that the technique can also be used in combination with chimney grafts in order to preserve side branches.

Conclusion

CERAB has proven to be the most optimal endovascular treatment option for aorto-iliac occlusive disease with regard to geometry and flow and is related to promising clinical outcomes. Prospective and comparative trials are necessary to elucidate the most optimal treatment algorithm for patients with aorto-iliac occlusive disease.

Meta-analysis of Individual Patient Data After Kissing Stent Treatment for Aortoiliac Occlusive Disease

PURPOSE

To evaluate short- and long-term technical and clinical outcomes after kissing stent treatment of aortoiliac occlusive disease (AIOD) based on an individual participant data (IPD) meta-analysis.

MATERIALS AND METHODS

A search of the Scopus database identified 156 articles on KS treatment of AIOD; of these 22 met the inclusion criteria. Authors of 19 articles with contact information were approached to join an IPD consortium. Eight author groups responded and 5 provided anonymized data for merging into an IPD database. The number of included procedures was equal before and after 2005. The primary study outcome was the cumulative patency at 24 months. Secondary outcomes were patency at up to 60 months, complications, and changes in Rutherford category and ankle-brachial index. The predictive value of stent protrusion length, pre-/postdilation, stent type, and patient demographics on primary patency were examined with Cox proportional hazard modeling; outcomes are reported as the hazard ratio (HR). The Kaplan-Meier method was employed to estimate patency rates.

RESULTS

In total, 605 (40.9%) of 1480 patients presented in the literature were included in the IPD analysis. The indication for intervention was intermittent claudication in 84.2% and critical limb ischemia in 15.8%. Lesions were classified as TransAtlantic Inter-Society Consensus (TASC) A or B in 52.8% and TASC C and D in 47.2%. The overall primary patency estimate was 81% at 24 months. Primary patency significantly increased after 2005 (p=0.005). Cox regression analysis revealed only age as a significant predictor of sustained primary patency (HR 0.60, p<0.005). Any previous endovascular intervention (HR 2.52, p=0.02) was the main predictor for loss of secondary patency; history of cardiovascular disease (HR 0.27, p=0.04) was the main predictor of sustained secondary patency.

CONCLUSION

The kissing stent technique has a good safety profile and acceptable patency rates up to 2 years, even in TASC C and D lesions, supporting an endovascular-first approach for AIOD.

Successful Off-Label Use of an Iliac Branch Device to Rescue an Occluded Aortofemoral Bypass Graft

Purpose: To report an alternative approach for rescue of an occluded aortofemoral bypass using the Gore Excluder Iliac Branch Endoprosthesis (IBE). Case Report: A 52-year-old man presented with acute right limb ischemia because of displaced and occluded iliac stents and was treated with aortofemoral bypass. On the third postoperative day, there was early bypass failure due to distal embolization from aortic thrombus. After fluoroscopy-guided balloon thrombectomy of the bypass, an endovascular bailout strategy was used. The Gore Excluder IBE was deployed below the renal arteries (with the external iliac limb opening in the surgical prosthesis and the gate opening within the aortic lumen). After antegrade catheterization of the gate, a Gore Viabahn endoprosthesis was inserted as the bridging endograft and deployed so that it landed just above the preimplanted aortoiliac kissing stents without overlapping them. Completion angiography showed technical success without complications; results were sustained at 1-year follow-up. Conclusion: The Gore Excluder IBE may represent a versatile solution for the rescue of complex cases when open surgery would be associated with a considerable risk. This off-label application of a well-recognized endovascular device is safe and feasible and may prove useful as a valuable alternative in properly selected patients.

Stent Protrusion >20 mm Into the Aorta: A New Predictor for Restenosis After Kissing Stent Reconstruction of the Aortoiliac Bifurcation

Purpose: To determine the long-term patency of aortoiliac kissing stents and to identify predisposing factors for the development of in-stent restenosis (ISR). Methods: A retrospective analysis was conducted of 105 patients (median age 60.9 years; 64 women) with symptomatic aortoiliac occlusive disease who had kissing stents implanted between 2001 and 2015. The indication for kissing stents was severe claudication in 91 (86.7%) patients and critical limb ischemia in 14 (13.3%). Lesions were TASC A in 52 (49.5%), B in 29 (27.6%), C in 4 (3.8%), and D in 20 (19%) patients. Twenty-five (23.8%) patients had heavily calcified lesions. In all, 210 stents were deployed [180 (85.7%) self-expanding and 30 (14.3%) balloon-expandable]. Follow-up included clinical evaluation, ankle-brachial index measurement, and duplex ultrasonography. Results: The median follow-up was 45 months. The primary patency rates were 93%, 86%, and 77% at 12, 24, and 60 months, respectively. Significant ISR developed in 23 (21.9%) patients (12 unilateral and 11 bilateral). Univariate Cox regression analysis revealed older age [hazard ratio (HR) 0.5, 95% confidence interval (CI) 0.31 to 0.81, p=0.004] and larger aortic diameter (HR 0.42, 95% CI 0.25 to 0.7, p<0.001) to be variables favoring long-term patency, while a longer aortic stent segment (HR 1.56, 95% CI 1.16 to 2.09, p=0.003) and a larger discrepancy between the summed stent diameters and the aortic diameter (HR 1.64, 95% CI 1.01 to 2.65, p=0.043) were associated with ISR development. Multivariate analysis showed a longer aortic stent segment to be the only significant determinant of ISR (HR 1.44, 95% CI 1.02 to 2.01, p=0.035). Conclusion: The kissing stent technique can be performed with good long-term patency. Patients whose iliac stents protrude too far into the aorta need closer follow-up.

High-Frame-Rate Contrast-enhanced US Particle Image Velocimetry in the Abdominal Aorta: First Human Results

Purpose To study the feasibility of high-frame-rate (HFR) contrast material-enhanced (CE) ultrasound particle image velocimetry (PIV), or echo PIV, in the abdominal aorta. Materials and Methods Fifteen healthy participants (six men; median age, 23 years [age range, 18-34 years]; median body mass index, 20.3 kg/m² [range, 17.3-24.9 kg/m²]) underwent HFR CE US. US microbubbles were injected at incremental doses (0.25, 0.5, 0.75, and 1.5 mL), with each dose followed by US measurement to determine the optimal dosage. Different US mechanical index values were evaluated (0.09, 0.06, 0.03, and 0.01) in a diverging wave acquisition scheme. PIV analysis was performed via pairwise cross-correlation of all captured images. Participants also underwent phase-contrast MRI. The echo PIV and phase-contrast MRI velocity profiles were compared via calculation of similarity index and relative difference in peak velocity. Results Visualization of the aortic bifurcation with HFR CE US was successful in all participants. Optimal echo PIV results were achieved with the lowest contrast agent dose of 0.25 mL in combination with the lowest mechanical indexes (0.01 or 0.03). Substantial bubble destruction occurred at higher mechanical indexes (≥0.06). Flow patterns were qualitatively similar in the echo PIV and MR images. The echo PIV and MRI velocity profiles showed good agreement (similarity index, 0.98 and 0.99; difference in peak velocity, 8.5% and 17.0% in temporal and spatial profiles, respectively). Conclusion Quantification of blood flow in the human abdominal aorta with US particle image velocimetry (echo PIV) is feasible. Use of echo PIV has potential in the clinical evaluation of aortic disease. © RSNA, 2018 Online supplemental material is available for this article.

A rare manifestation of severe critical limb ischemia caused by solitary aorto-iliac occlusive disease

Currently, there are more opportunities to treat patients complicated with critical limb ischemia (CLI), which is a very dismal medical condition associated with a high risk of major amputation, disability and death. Because CLI is usually caused by multi-level occlusive atherosclerotic disease, the condition of CLI induced by aorto-iliac occlusive disease (AIOD) alone is thought to be a rare pathological entity. We encountered a patient with severe CLI caused by solitary AIOD. Three vascular access routes were established and stiff guidewires retrogradely passed the occluded arteries on both sides. We deployed two self-expandable bare metal stents and complete revascularization led to wound healing. Recent improvements of catheter devices and procedural techniques related to endovascular treatment (EVT) have enabled us to safely recanalize complex vascular lesions of the lower extremities. Therefore, an EVT strategy is one of the favorable treatment options for CLI patients who are contraindicated for surgical treatments.

Endovascular Treatment for Steno-Occlusive Iliac Artery Disease: Safety and Long-Term Outcome

We evaluated safety and long-term outcome of endovascular therapy for steno-occlusive iliac artery disease. All endovascular procedures of iliac artery lesions performed at our institution between 2001 and 2014 (n = 676) were retrospectively analyzed. The overall technical success rate was 99% and yielded 100% for stenoses (n = 596) and 95% for chronic total occlusions (n = 80). Lesion complexity defined by the Trans-Atlantic Inter-Society Consensus (TASC) II classification had no impact on success rates (TASC A + B vs C + D; 99.5% vs 98.6%, P = .359). During a median follow-up of 11 months, the overall rate of restenosis was 9.4%. After 1 and 3 years, the primary patency rates were 94% and 86% and the secondary patency rate was 100%, respectively. The TASC II classification had no impact on long-term patency rates (TASC A + B vs C + D; 86% vs 81%). In a multivariable analysis, stent diameter remained the only significant predictor for restenosis (hazard ratio: 0.58; 95% confidence interval: 0.41%-0.81%; P = .002). In this single-center retrospective study, endovascular therapy for steno-occlusive iliac artery disease was associated with high technical and clinical success rates as well as an excellent long-term patency rate irrespective of lesion complexity.

Use of a Thoracic Endograft in an Acute Abdominal Aortic Setting: Case Report and Literature Review

PURPOSE

We report the case of a thoracic endograft used to achieve exclusion of a ruptured proximal paranastomotic abdominal aortic aneurysm (PAAA) as a consequence of aortic ballooning.

CASE REPORT

A type I proximal endoleak was evidenced following endovascular repair of a PAAA with an aortic cuff. The leak was treated with ballooning, which caused distal aortic rupture. A thoracic endograft was deployed inside the cuff, achieving complete exclusion. At 1 year, there are no signs of migration or endoleak with complete PAAA thrombosis, according to computed tomographic angiography.

CONCLUSION

In hostile proximal abdominal aortic neck, challenging anatomies, or urgent cases, the structural adaptability of thoracic endografts could provide safe and successful abdominal aortic endovascular exclusion.

Endovascular Reconstruction for Chronic Infrarenal Aortoiliac Occlusive Disease

According to the 2007 TransAtlantic Inter-Society Consensus (TASC II) guidelines, surgery is the preferred treatment for extensive (TASC II type C and D) aortoiliac occlusive disease (AIOD). Recent studies, however, have shown that endovascular management can be an effective first-line treatment option for TASC II type C and D categories. While endovascular therapy is now commonly performed in patients with TASC II type D lesions, very few studies have investigated the feasibility and effectiveness of extending endovascular therapy to the most severe subcategory of TASC II D lesions, chronic infrarenal aortoiliac occlusion (CIAO). Herein, we present our technique for endovascular treatment of CIAO which relies on bidirectional subintimal aortoiliac dissection, wire snare for true lumen reentry, and combined balloon-expandable and self-expanding covered stent reconstruction of the aortic bifurcation and bilateral iliac arteries. This technique safely extends the reach of endovascular therapy to the most severe subcategory of TASC II D AIOD, CIAO. It is a viable minimally invasive alternative to aortobifemoral bypass surgery. Long-term follow-up of larger cohorts is needed to verify clinical efficacy and durability of therapy.

In vivo geometry of the kissing stent and covered endovascular reconstruction of the aortic bifurcation configurations in aortoiliac occlusive disease

Objectives

Various configurations of kissing stent (KS) configurations exist and patency rates vary. In response the covered endovascular reconstruction of the aortic bifurcation configuration was designed to minimize mismatch and improve outcome. The aim of the current study is to compare geometrical mismatch of kissing stent with the covered endovascular reconstruction of the aortic bifurcation configuration in vivo.

Methods

Post-operative computed tomographic data and patient demographics from 11 covered endovascular reconstruction of the aortic bifurcation and 11 matched kissing stent patients were included. A free hand region of interest and ellipse fitting method were applied to determine mismatch areas and volumes. Conformation of the stents to the vessel wall was expressed using the D-ratio.

Results

Patients were mostly treated for Rutherford category 2 and 3 (64%) with a lesion classification of TASC C and D in 82%. Radial mismatch area and volume for the covered endovascular reconstruction of the aortic bifurcation group was significantly lower compared to the kissing stent configuration (P < 0.05). The D-ratio did not significantly differ between groups. Measurements were performed with good intra-class correlation. There were no significant differences in the post-procedural aortoiliac anatomy.

Conclusions

The present study shows that radial mismatch exists in vivo and that large differences in mismatch exist, in favour of the covered endovascular reconstruction of the aortic bifurcation configuration. Future research should determine if the decreased radial mismatch results in improved local flow profiles and subsequent clinical outcome.

Simultaneous Kissing Stenting: A Valuable Technique for Reconstructing the Stenotic Initial Segment of the Right Subclavian Artery

Atherosclerotic stenosis or occlusion often involves the subclavian artery. For lesions that are close to the orifice of the right subclavian artery, stenting of the right subclavian artery itself blocks the pathway from the innominate artery to the right carotid artery and causes problems in patients with multiple angiostenosis, especially involving the right carotid system. In this study, we report 2 cases using simultaneous kissing stenting (SKS) of the right subclavian artery and the right carotid artery to relieve right subclavian stenosis and maintain right carotid system patency. Standard stenting methods were used to perform SKS. Two self-expanding stents were implanted simultaneously into the initial segment of the right subclavian artery and the right carotid artery, forming a "Y" shape, with the overlap of the proximal segments in the innominate artery ≥5 mm. After SKS, the stenosed right subclavian artery was dilated, and the patency of the right carotid system was maintained. The symptoms of patients were relieved and the stents were intact at several months of follow-up. In conclusion, SKS of the right subclavian artery and the right carotid artery might be a safe and effective procedure when the stenotic or occlusive lesion in the initial segment of the right subclavian artery is close to the orifice, and lesions (or potential ones) exist in the right carotid system.

Endovascular treatment of TransAtlantic Inter-Society Consensus D aortoiliac occlusive disease using unibody bifurcated endografts

OBJECTIVE

Aortobifemoral bypass has been the gold standard treatment for extensive aortoiliac occlusive disease. Endovascular therapy and stenting of aortic and iliac occlusive lesions has proven to be efficacious, especially when dealing with short segment lesions. Endovascular treatment of TransAtlantic Inter-Society Consensus II (TASC) D aortoiliac occlusive lesions remains a challenge, but a valuable treatment option in poor surgical candidates. We present our operative technique and midterm results in treating TASC D aortoiliac occlusive disease using unibody bifurcated endografts.

METHODS

We performed a retrospective review of patients with TASC D aortoiliac occlusive disease who underwent transfemoral endovascular revascularization with the Endologix Powerlink unibody bifurcated endograft (Endologix, Irvine, Calif). Demographic data, operative details, and outcomes were collected. Paired t-tests were performed to compare preoperative and postoperative ankle brachial indexes.

RESULTS

Between March 2009 and July 2011, 10 high-risk patients (8 male and 2 female) for a traditional aortobifemoral bypass were treated using this endovascular technique. The mean age was 59 ± 6 years (range, 50-69 years). All patients presented with rest pain, and four with tissue loss. Technical success was 100%, with two patients requiring brachial access and eight patients requiring additional stent placement. Postoperatively, all patients reported clinical improvement with resolution of ischemic symptoms. Mean improvement ankle brachial index was 0.50 ± 0.08 (P = .028) and 0.50 ± 0.01 (P = .034) in the left and right legs, respectively. Mean follow-up time was 40 ± 24 months (range, 4-81 months). The primary and secondary patency rates were 80% and 100%, respectively. Complications requiring early reintervention occurred in two patients and included one expanding hematoma from the percutaneous access site and one acute iliac artery thrombosis. Additionally, one patient underwent repeat angioplasty/stenting for threatened endograft limbs at 4 months. One patient expired during follow-up from an unrelated cardiac cause 19 weeks postoperatively.

CONCLUSIONS

This series demonstrates that endovascular repair using a unibody bifurcated endograft for TASC D aortoiliac occlusive disease is feasible, effective, and has excellent midterm patency. It should be considered an effective treatment option when the disease process involves the aorta, in particular if the patient is surgically unfit for a traditional aortobifemoral bypass. The unibody configuration preserves the anatomic aortic bifurcation, which is particularly important in patients with peripheral occlusive disease who are deemed to undergo subsequent endovascular interventions.

Treatment of Aortoiliac Occlusive Disease with the Endologix AFX Unibody Endograft

OBJECTIVE/BACKGROUND

Aorto-bifemoral bypass remains the gold standard for treatment of aortoiliac occlusive disease (AIOD) in patients with advanced (TASC D) lesions, but has significant associated morbidity and mortality. Treatment with a unibody stent-graft positioned at the aortic bifurcation is a potential endovascular option for the treatment of AIOD. The current study examines the safety, efficacy, and early patency rates of the Endologix AFX unibody stent-graft for treatment of AIOD.

METHODS

A multicenter retrospective review was conducted of patients treated exclusively for AIOD with the AFX device. Primary, assisted primary, and secondary patency rates were noted. Clinical improvement was assessed using Rutherford classification and ankle brachial index. Mean duration of follow-up was 22.2 ± 11.2 months. Ninety-one patients (56 males [62%]) were studied.

RESULTS

Sixty-seven patients (74%) presented with lifestyle-limiting intermittent claudication and the remaining 24 (26%) had critical limb ischemia. Technical success was 100%. Complications included groin infection (n = 4 [4%]), groin hematoma (n = 4 [4%]), common iliac rupture (n = 4 [4%]), iliac dissection (n = 4 [4%]), and thromboembolic event (n = 3 [3%]; one femoral, one internal iliac artery, and one internal iliac with bilateral popliteal/tibial thromboemboli). Thirty-day mortality was 1% (1/91) resulting from a case of extensive pelvic thromboembolism. At 1 year, 73% of patients experienced improvement in Rutherford stage of -3 or greater compared with baseline. Nine patients (10%) required 16 secondary interventions. At all time points, primary patency rates were > 90%, assisted patency rates were > 98%, and secondary patency rates were 100%.

CONCLUSION

This is the largest study to examine the use of the Endologix AFX unibody stent-graft for the treatment of AIOD. Use of the AFX stent-graft appears to be a safe and effective endovascular treatment for complex AIOD.

Valve-Like and Protruding Calcified Intimal Flap Complicating Common Iliac Arteries Kissing Stenting

Endovascular therapy for iliac artery chronic total occlusions is nowadays associated with low rates of procedure-related complications and improved clinical outcomes, and it is predominantly used as first-line therapy prior to aortobifemoral bypass grafting. Herein, we describe the case of a patient presenting with an ischemic left foot digit ulcer and suffering complex aortoiliac lesions, who received common iliac arteries kissing stents, illustrating at final antegrade and retrograde angiograms the early recognition of a blood flow obstructing valve-like calcified intimal flap protruding through the stent struts, which was obstructing antegrade but not retrograde unilateral iliac arterial axis blood flow. The problem was resolved by reconstructing the aortic bifurcation at a more proximal level. Completion angiogram verified normal patency of aorta and iliac vessels. Additionally, a severe left femoral bifurcation stenosis was also corrected by endarterectomy-arterioplasty with a bovine patch. Postintervention ankle brachial pressure indices were significantly improved. At the 6-month and 2-year follow-up, normal peripheral pulses were still reported without intermittent claudication suggesting the durability of the procedure. Through stent-protruding calcified intimal flap, is a very rare, but existing source of antegrade blood flow obstruction after common iliac arteries kissing stents.

Korean Guidelines for Interventional Recanalization of Lower Extremity Arteries

Peripheral arterial occlusive disease caused by atherosclerosis can present with intermittent claudication or critical limb ischemia. Proper diagnosis and management is warranted to improve symptoms and salvage limbs. With the introduction of new techniques and dedicated materials, endovascular recanalization is widely performed for the treatment of peripheral arterial occlusive disease because it is less invasive than surgery. However, there are various opinions regarding the appropriate indications and procedure methods for interventional recanalization according to operator and institution in Korea. Therefore, we intend to provide evidence based guidelines for interventional recanalization by multidisciplinary consensus. These guidelines are the result of a close collaboration between physicians from many different areas of expertise including interventional radiology, interventional cardiology, and vascular surgery. The goal of these guidelines is to ensure better treatment, to serve as a guide to the clinician, and consequently, to contribute to public health care.

Successful endovascular treatment for high take off aorto-iliac occlusive disease

A 73-year-old man with a history of intermittent claudication for the previous six years visited our hospital. His ankle-brachial index (ABI) was very low on both sides, and computed tomography (CT) indicated bilateral aorto-iliac occlusive disease (AIOD). As he refused to undergo open surgery, endovascular treatment (EVT) was administered. After the first and second EVT sessions, the intermittent claudication improved completely. In addition, the ABI normalized (right: 1.01, left: 0.99), and CT demonstrated full expansion of the stents. His post-EVT course was uneventful for 18 months. The use of EVT to treat AIOD is technically feasible and may serve as a potential treatment option for patients with an inoperable condition.

Long-term outcomes of endovascular therapy for aortoiliac bifurcation lesions in the real-AI registry

PURPOSE

To report long-term outcomes of endovascular therapy (EVT) for aortoiliac bifurcation lesions.

METHODS

Patients enrolled in the multicenter REtrospective AnaLysis of Aorto-Iliac stenting (REAL-AI) registry in Japan were pooled. Of 2096 patients who underwent EVT for de novo aortoiliac disease between January 2005 and December 2009, 190 patients (148 men; mean age 70±9 years) had aortoiliac bifurcation lesions that were treated with stents, whose configuration (single, V, or kissing) and type (balloon-expandable or self-expanding) were subjected to regression analysis to determine any impact on primary patency along with other demographic, clinical, and lesion characteristics, including Trans-Atlantic Inter-Society Consensus II C/D classification. The primary endpoints were restenosis and target lesion revascularization (TLR). Secondary endpoints were all-cause death, major cardiovascular events, and major cardiovascular + limb events.

RESULTS

The overall complication rate was 6.3%, and 1- and 5-year primary patency rates were 87% and 73%, respectively. Over a mean follow-up of 31±15 months, there were 36 (19.0%) restenoses, 22 (11.6%) TLRs, and 4 (2.1%) reocclusions; stent fracture (2, 1.1%) and major amputation (2, 1.1%) were rare. Only female gender [adjusted hazard ratio (AHR) 4.26, 95% CI 1.89 to 9.71, p<0.001] and residual diameter stenosis (AHR 1.04, 96% CI 1.01 to 1.06, p=0.01) were independent predictors of primary patency.

CONCLUSION

Stenting for aortoiliac bifurcation lesions was found to be safe and effective. Neither stent configuration nor type appeared to affect vessel patency in true bifurcation lesions.

[Occlusion of the aorta and iliac arteries]

Occlusion of the aorta and the iliac arteries leads to an insufficient perfusion of the legs and the genital and gluteal region. The occurring symptoms may be variable, mainly depending on the collateralization network of the internal iliac artery (IIA) circulation. Various differential diagnoses need to be excluded. Invasive therapy is almost always inevitable if an aortoiliac stenosis is established. With good patency rates and low mortality rates the indications for reconstructive procedures are liberally interpreted; therefore, invasive therapy can be performed in the early stages of claudication in certain situations. Due to lower invasiveness and therefore lower risk of complications while showing comparable long-term patency rates, endovascular treatment is the preferred first line therapy for the majority of occlusions. Because aortoiliac occlusion processes also affect patients who are actively involved in a professional career, the indications for invasive therapy can be attained even in Fontaine stage IIa.

Geometrical consequences of kissing stents and the Covered Endovascular Reconstruction of the Aortic Bifurcation configuration in an in vitro model for endovascular reconstruction of aortic bifurcation

OBJECTIVE

Kissing stents (KS) are commonly used to treat aortoiliac occlusive disease, but patency results are often lower than those of isolated stents. The Covered Endovascular Reconstruction of the Aortic Bifurcation (CERAB) technique was recently introduced to reconstruct the aortic bifurcation in a more anatomical and physiological fashion. The aim of this study is to compare the geometrical consequences of various stent configurations in vitro.

METHODS

Anatomic vessel phantoms of the aortoiliac bifurcation were created to accommodate stent configurations. Self-expandable nitinol KS, balloon-expandable covered KS, and two versions of the CERAB configuration were deployed, one with the iliac legs positioned inside the tapered part of the aortic cuff (1) and one with the legs deployed above this level (2). Computed tomography data were obtained to assess the geometry. The conformation ratio (D-ratio) was calculated by use of the ratio of the major and minor axes. The proximal mismatch area, mean mismatch area, and total mismatch volume were calculated.

RESULTS

The highest D-ratios were observed in the nitinol KS and the CERAB configuration, implying an ideal "double-D" shape. The proximal and mean mismatch areas were four- to sixfold lower in the CERAB (1) configuration when compared with nitinol KS and CERAB (2), respectively, whereas the covered KS had the highest mismatch area. Nitinol and covered KS had the largest mismatch volume, whereas the mismatch volume was the lowest in the CERAB (1) configuration.

CONCLUSIONS

Although nitinol self-expandable stents have a high stent conformation, the lowest radial mismatch was found in the CERAB (1) configuration, supporting the hypothesis that the CERAB configuration is the most anatomical and physiological reconstruction of the aortic bifurcation. Within the CERAB configuration, the two limbs are ideally positioned inside the tapering portion of the cuff, minimizing mismatch.