Covered Balloon Expandable Stents Research Articles

Endovascular treatment of aortic coarctation using covered balloon-expandable stents—a systematic review and meta-analysis

ObjectivesBalloon dilation followed by balloon-expandable stent implantation is an effective treatment for improving hemodynamic status in patients with coarctation of the aorta (CoA). However, limited evidence exists regarding the safety and efficacy of covered balloon-expandable stents (CBSs) in a large cohort. In this meta-analysis, we aimed to evaluate the overall success rates, hemodynamic and anatomical benefits, complications, and mid-term results of CBSs in treating CoA.MethodsThe PubMed, Embase, and Cochrane Library databases were systemically searched for studies reporting outcomes of CBSs in treating CoA. Single-group rate meta-analyses were performed to calculate estimated pooled procedural success rates, the incidence of complications, and re-coarctation rates. A meta-analysis using standardized mean differences was conducted to compare pre- and postoperative trans-coarctation pressure gradients (PGs), coarctation diameter, and overall changes in systolic blood pressure (SBP). Subgroup analyses were performed to identify potential sources of heterogeneity.ResultsThe final analysis included 12 studies with a total of 411 patients. The estimated pooled procedural success rate was 100% [95% confidence interval (CI): 98%–100%, I2 = 0, P = 0.78]. Significant decreases in trans-coarctation PGs and SBP were observed. The pooled incidences of stent-related, aortic, and access site complications were 2% (95% CI: 0%–5%, I2 = 30.4%, P = 0.15), 2% (95% CI: 0%–4%, I2 = 0%, P = 0.76), and 3% (95% CI: 1%–7%, I2 = 52.9%, P = 0.02), respectively. Subgroup analyses showed that implantation of BeGraft stents was related to a significantly higher incidence of access site complications.ConclusionCovered balloon-expandable stent implantation in treating CoA is safe and effective with high procedural success rates, an acceptable incidence of complications, and a low incidence of re-coarctation.Systematic Review Registrationhttps://www.crd.york.ac.uk/PROSPERO/, PROSPERO (CRD42023430356).

Initial Experience of the Covered Endovascular Reconstruction of Iliac Bifurcation Technique.

The distal landing zone in iliac arteries represents an important issue during endovascular repair of abdominal aortic aneurysms (EVAR). The aim of this study is to present a case series for landing in the external iliac artery (EIA) during EVAR while preserving blood flow in the internal iliac artery (IIA) with the covered endovascular reconstruction of the iliac bifurcation (CERIB) technique. This is a single-center, retrospective analysis of prospectively collected data of patients that underwent EVAR either for intact abdominal aortic aneurysm (AAA) or previous failed EVAR from December 2022 up to September 2023. Indications for treatment were presence of common iliac artery aneurysm (CIAA), short CIA, or endoleak type Ib (ETIb). For the distal sealing zone, we used balloon-expandable covered stent (BXCS). Primary outcomes were technical success and first-month patency rate. Secondary outcomes were endoleak and re-intervention rate. Sixteen patients being treated with 20 CERIBs were included in the study. Four patients had a previous failed EVAR, while 3 patients were treated urgently for a symptomatic para-renal aneurysm. The indications for treatment were EIb (n=2), short CIA (n=4), CIAA with narrow lumen (n=3), and CIA aneurysm (n=11). Platforms that were used were the Cook Zenith Alpha (n=5), Gore C3 (n=2 and 3 limbs), Endurant IIs (n=2, and 3 limbs), and a t-branch device (n=3). Technical success rate was 100% with no adjunctive procedure. No death or re-intervention was recorded for all patients at postoperative 30-day period and at 6 months for 2 patients. At first-month CTA, patency rate was 100% (20/20), while in 2 patients that had 6-month CTA, the patency was also 100% (2/2). No kinking or stenosis was also noted. Two patients had ETIII after branched EVAR (BEVAR), 2 patients had ETII, and 1 patient had gutter ET in the area of the CERIB. The CERIB technique seems to be effective and safe in the early period. It is suitable with a variety of commercial endograft platforms. It may be a valuable alternative to iliac branch devices when there are anatomical considerations. Longer follow-up is needed to conclude for long-term patency and durability. The distal landing zone in iliac arteries represents an important issue during EVAR while it is important to preserve blood flow in the internal iliac artery. The covered endovascular reconstruction of the iliac bifurcation (CERIB) technique is a technique for the preservation of internal iliac arteries during EVAR, while it is suitable with a variety of commercial endograft platforms. The CERIB technique seems to be effective and safe in the early period. It may be valuable alternative to iliac branch devices when there are anatomical considerations.

Three-Dimensional Geometric Analysis of Viabahn VBX Bridging Stent Grafts in Fenestrated Endovascular Aortic Repair: A Multicenter, Retrospective Cohort Study.

The primary aim of this study was to assess the 3-dimensional flare geometry of the Gore Viabahn VBX balloon-expandable covered stent (BECS) after fenestrated endovascular aortic repair (FEVAR) and to determine and visualize BECS-associated complications. This multicenter retrospective study included patients who underwent FEVAR between 2018 and 2022 in 3 vascular centers participating in the VBX Expand Registry. Patients with at least one visceral artery treated with the VBX and with availability of 2 post-FEVAR computed tomography angiography (CTA) scans (follow-up [FU] 1: 0-6 months; FU2: 9-24 months) were included. The flare geometry of the VBX, including flare-to-fenestration distance, flare-to-fenestration diameter ratio, flare angle, and apposition with the target artery were assessed using a vascular workstation and dedicated CTA applied software. In total, 90 VBX BECS were analyzed in 43 FEVAR patients. The median CTA FU for FU1 and FU2 was 35 days (interquartile range [IQR], 29-51 days) and 14 months (IQR, 13-15 months), respectively. The mean flare-to-fenestration distance was 5.6±2.0 mm on FU1 and remained unchanged at 5.7±2.0 mm on FU2 (p=.417). The flare-to-fenestration diameter ratio was 1.19±0.17 on FU1 and remained unchanged at 1.21±0.19 (p=.206). The mean apposition length was 18.6±5.3 mm on FU1 and remained 18.6±5.3 mm (p=.550). The flare angle was 31°±15° on FU1 and changed to 33°±16° (p=.009). On FU1, the BECS-associated complication rate was 1%, and the BECS-associated reintervention rate was 0%. On FU2, the BECS-associated complication rate was 3%, and the BECS-associated reintervention rate was 1%. The flare geometry of the VBX bridging stent did not change significantly during 14 months follow-up in this study. Three-dimensional geometric analysis of the flare may contribute to identify the origin of endoleaks and occlusions, but this should be confirmed in a larger study including enough patients and BECS to compare complicated and uncomplicated cases. The three-dimensional flare geometry of the Gore Viabahn VBX BECS was assessed on the first and second postoperative CTA scans, and geometrical changes during this period were identified. For BECS that were diagnosed with a type 3c endoleak or occlusion, the BECS geometry was analyzed to detect geometrical components that were related to the complication. Geometric analysis of the flare may help to better detect and identify the cause of such complications.

A Cost-Consequence Analysis Comparing Balloon-Expandable Covered Stents for the Management of Aortoiliac Occlusive Disease.

To compare procedural and long-term costs associated with the use of Balloon-Expandable Covered Stents (BECS) in the management of Aortoiliac Occlusive Disease (AIOD). A cost-consequence model was developed to simulate the intra- and post-operative management of patients with AIOD from the perspective of private health-payers. The study assessed the costs of the LifeStream (BD, Franklin Lakes, New Jersey), iCAST/Advanta V12 (Getinge, Goteborg, Sweden), BeGraft Peripheral (Bentley, Hechingen, Germany), and Viabahn Balloon Expandable (VBX) (W.L. Gore, Flagstaff, Arizona) BECS devices. Device costs were identified from the Australian Prosthesis List, whereas clinical outcomes of BECS were estimated from a systematic review of the literature. Costs were calculated over 24 and 36 month time horizons and reported in US dollars. Long-term, per-patient cost of each device at 24 and 36 months was $6253/$6634 for the LifeStream; $6359/$6869 for the iCAST/Advanta V12; $4806 (data available to 24 months) for the BeGraft Peripheral; and $4839/$5046 for the Viabahn VBX, respectively. Most of the cost difference was attributed to the number of stents required per treated limb and frequency of clinically-driven target lesion revascularization events. Best-available clinical evidence and economic modeling demonstrates that the BeGraft Peripheral and Viabahn VBX were of similar cost and the least costly options at 24 months, whereas at 36 months, the lowest cost BECS option for the treatment of AIOD was the Viabahn VBX. This analysis supports economically informed decision-making for health-payers managing systems that care for patients with AIOD. Stent length and avoiding reintervention were identified as key areas of cost-saving for future BECS development.

In Vitro Radiological Evaluation of Different Types of Chimney Stents Using a Silicon Flow Model with Adjustable Physiological Simulating Conditions

To evaluate invitro the performance of invivo published covered or bare metal chimney stents (ChSs) in combination with the Endurant II abdominal endograft (Medtronic) as the only CE approved main graft (MG) in the treatment of juxtarenal abdominal aortic aneurysms with the chimney endovascular aneurysm repair (chEVAR) technique. Bench top experimental study. A silicon flow model with adjustable physiological simulating conditions and patient based anatomy was used to test nine different MG-ChS combinations: Advanta V12 (Getinge); BeGraft+ (Bentley); VBX (Gore & Associates Inc.); LifeStream (Bard Medical); Dynamic (Biotronik); Absolute Pro (Abbott); double Absolute Pro; Viabahn (Gore) lined with Dynamic; and Viabahn lined with EverFlex (Medtronic). Angiotomography was performed after each implantation. DICOM data were analysed blindly twice per observer by three independent experienced observers. Each blinded evaluation was performed at one month intervals. The main analysed parameters were the area of gutters, MG and ChS maximum compression, and the presence of infolding. Bland-Altman analysis confirmed adequate results correlation (p < .05). Each employed ChS showed significantly different performance favouring the balloon expandable covered stent (BECS). The smallest gutter area was seen in the combination with Advanta V12 (0.26 cm2). MG infolding was observed in all tests. The lowest ChS compression was observed in the combination with BeGraft+ (compression 4.91%, D ratio 0.95). In our model, BECSs showed higher angulations than bare metal stents (BMSs) (p < .001). This invitro study shows the variability of performance with each theoretically possible ChS and explains the divergent ChS outcomes in the published literature. BECS in combination with the Endurant abdominal device confirms their superiority vs. BMS. The presence of MG infolding in each test underlines the need for prolonged kissing ballooning. Angulation evaluation and comparison with other invitro and invivo publications demands the need for further investigation in transversely or upwardly oriented target vessels.

Three-Dimensional Geometric Analysis of Balloon-Expandable Covered Stents Improves Classification of Complications after Fenestrated Endovascular Aneurysm Repair.

In balloon-expandable covered stent (BECS) associated complications after fenestrated endovascular aneurysm repair (FEVAR), geometric analysis may determine the cause of failure and influence reintervention strategies. This study retrospectively classifies BECS-associated complications based on computed tomographic angiography (CTA) applied geometric analysis. BECS-associated complications of FEVAR-patients treated in two large vascular centers between 2012 and 2021 were included. The post-FEVAR CTA scans of complicated Advanta V12 BECSs were analyzed geometrically and complications were classified according to its location in the BECS. BECS fractures were classified according to an existing classification system. In 279 FEVAR-patients, 34 out of the 683 included Advanta V12 BECS (5%) presented with a complication. Two Advanta V12 complications occurred during the FEVAR procedure and 32 occurred during follow-up of which five post-FEVAR CTA scans were missing or not suitable for analysis. In the remaining 27 BECSs complications were classified as (endoleaks (n = 8), stenoses (n = 4), occlusions (n = 6), fractures (n = 3), and a combination of complications (n = 6)). All BECSs associated complications after FEVAR with available follow up CTA scans could be classified. Geometric analysis of BECS failure post-FEVAR can help to plan the reintervention strategy.

In Vitro Geometry Analysis of Fenestrations in Endovascular Aneurysm Repair

Purpose: Changes in the flared end of balloon-expandable covered stent (BECS) may precede BECS-associated complications but are not regularly assessed with computed tomographic angiography (CTA) after fenestrated endovascular aneurysm repair (FEVAR). Validation of the flare geometric analysis (FGA) and assessment of intraobserver and interobserver variability are investigated in this study. Methods: Two series of 3 BeGraft BECSs (Bentley InnoMed GmbH, Hechingen, Germany) and 1 series of 3 Advanta V12 BECSs (Getinge AB, Göteborg, Sweden) were deployed in 3 side branches (45°, 60°, and 90° aortic branch angles) of an aorta phantom model. A standard post-FEVAR CTA scan was acquired. Computed tomographic angiography–derived measurements consisted of centerline reconstructions and placement of 3-dimensional coordinate markers by 2 observers in a vascular workstation. Flare geometric analysis calculates 3 BECS parameters: the circumferential flare-to-fenestration distance (FFD), which is the distance from the proximal end of the flare to fenestration, and diameters at the proximal end of the flare (Dflare) and at the fenestration (Dfenestration). Computed tomographic angiography–derived measurements were validated against microscopy measurements. Bland-Altman plots were used to determine the intraobserver and interobserver variability of the BECS parameters and intraclass correlation coefficient (ICC). Results: For each BECS, the FFD at 4 equidistant quadrants of the circumference, Dflare, and Dfenestration were calculated. The mean difference and repeatability coefficient (RC) of the validation were 0.8 (2.1) mm for FFD, 0.4 (1.0) mm for Dflare, and −0.2 (1.2) mm for Dfenestration. The mean intraobserver and interobserver difference (RC) was 0.5 (1.6) mm and 0.7 (2.6) mm for FFD, 0.1 (0.6) mm and 0.1 (0.7) mm for Dflare, and −0.1 (0.8) mm and −0.8 (1.0) mm for Dfenestration. The mean ICC of intraobserver variability was 0.86 for FFD, 0.94 for Dflare, and 0.78 for Dfenestration. The mean ICC of interobserver variability was 0.77 for FFD, 0.92 for Dflare, and 0.48 for Dfenestration. Conclusion: This study showed that FGA of the flared ends of BECS can be performed with high accuracy in a phantom model, with good intraobserver and interobserver variability. Flare geometric analysis can be used to determine flare geometry of the BECS on standard post-FEVAR CTA scans.

Outcomes of Advanta V12 Covered Stents After Fenestrated Endovascular Aneurysm Repair

Purpose: Fenestrated endovascular aneurysm repair (FEVAR) is a well-established endovascular treatment option for pararenal abdominal aortic aneurysms in which balloon-expandable covered stents (BECS) are used to bridge the fenestration to the target vessels. This study presents midterm clinical outcomes and patency rates of the Advanta V12 BECS used as a bridging stent. Methods: All patients treated with FEVAR with at least 1 Advanta V12 BECS were included from 2 large-volume vascular centers between January 2012 and December 2015. Primary endpoints were freedom from all-cause reintervention, and freedom from BECS-associated complications and reintervention. BECS-associated complications included significant stenosis, occlusion, type 3 endoleak, or stent fracture. Secondary endpoints included all-cause mortality in-hospital and during follow-up. Results: This retrospective study included 194 FEVAR patients with a mean age of 72.2±8.0 years. A total of 457 visceral arteries were stented with an Advanta V12 BECS. Median (interquartile range) follow-up time was 24.6 (1.6, 49.9) months. The FEVAR procedure was technically successful in 93% of the patients. Five patients (3%) died in-hospital. Patient survival was 77% (95% CI 69% to 84%) at 3 years. Freedom from all-cause reintervention was 70% (95% CI 61% to 78%) at 3 years, and 33% of all-cause reinterventions were BECS associated. Complications were seen in 24 of 457 Advanta V12 BECSs: type 3 endoleak in 8 BECSs, significant stenosis in 4 BECSs, occlusion in 6 BECSs, and stent fractures in 3 BECSs. A combination of complications occurred in 3 BECSs: type 3 endoleak and stenosis, stent fracture and stenosis, and stent fracture and occlusion. The freedom from BECS-associated complications for Advanta V12 BECSs was 98% (95% CI 96% to 99%) at 1 year and 92% (95% CI 88% to 95%) at 3 years. The freedom from BECS-associated reinterventions was 98% (95% CI 95% to 100%) at 1 year and 94% (95% CI 91% to 97%) at 3 years. Conclusion: The Advanta V12 BECS used as bridging stent in FEVAR showed low complication and reintervention rates at 3 years. A substantial number of FEVAR patients required a reintervention, but most were not BECS related.

Pressure gradient measurement to verify hemodynamic results of the chimney endovascular aortic repair (chEVAR) technique.

PurposeThe use of the pressure gradient measurements to assess the renal artery flow hemodynamics after chimney endovascular aortic repair (chEVAR).MethodsThe study was a prospective analysis of 37 chEVAR procedures performend in 24 patients with perirenal aortic aneurysm. In all patients the measurement of: distal renal artery pressure (Pd), aortic pressure (Pa), Pd/Pa ratio (Pd/Pa) and mean gradient (MG) between the aorta and the distal renal artery were performed. Measurements were taken with 0.014 inch pressure wire catheter before and after the chEVAR procedure. MG greater than 9 mmHg and Pd/Pa ratio below 0.90 were considered as the measures of a significant decrease in distal pressure that limited flow in renal arteries. The 6 month follow-up computed tomographic angiography (CTA) was performed in all patients to diagnose potential endoleak presence and to verify the patency of the chimney stent-grafts.ResultsAll procedures were successful, and no periprocedural complications were observed in any of the patients. The mean gradient values before and after the chimney implantation did not change significantly (6,2±2,0 mmHg and 6,8±2,2 mmHg, respectively). Similarly, no significant change in Pd/Pa values was noted with the value of 0.9 observed both before and after the procedure. All chimney stents were patent on the control CTA. Type Ia endoleak was found in 4 (10.8%) patients.ConclusionsThe application of the described technique seems to be a safe method which allows a direct measurement of renal artery flow hemodynamics before and after chimney implantation during the chEVAR technique. The use of covered balloon expandable stents, ensures the proper blood flow in the renal arteries during the chEVAR technique.

Midterm results of kissing stent reconstruction of the aortoiliac bifurcation.

PurposeOne subset of peripheral arterial disease is aortoiliac occlusive diseases (AIOD). AIOD is the term for all arterial lesions between the infrarenal distal aorta and common femoral artery. Implantation of kissing stents (KS) with covered stents (CS), bare-metal stents (BMS) is one of the endovascular treatment (ET) modalities for AIOD involving aortic bifurcation. In this study, we report the outcomes of the KS technique in infrarenal AIOD.MethodsBetween January 2014 and September 2017, 31 patients who underwent ET were treated with KS technique either with balloon-expandable BMS or balloon-expandable CS. Technical details, clinical success, complications, and patency at follow-up were documented.ResultsThe majority of patients were male (77.4%), and the median age was 62 years (range, 45–78 years). All patients were classified according to the TASC II criteria. Eight patients (25.8%) were classified as TASC B. Fifteen patients (48.4%) were classified as TASC C, and 8 patients (25.8%) were classified as TASC D. These 23 patients were classified as complex AIOD group. BMS was used in 17 patients (54.8%), and CS was used in 14 patients (45.2%). Technical and clinical success was achieved in 100% of treated cases. The median follow-up was 24 months (range, 24–34 months). Primary patency rates at 12, 18, and 24 months after ET were 100%, 96.8%, and 90.3%, respectively.ConclusionWe found that the KS technique has satisfying 24-month results, even in complex AIOD lesions, with high technical success and acceptable midterm patency. Key Words: Aorta, Arterial occlusive diseases, Endovascular procedures, Iliac artery, Stents

Impact of bridging stent design and configuration on branch vessel durability after fenestrated endovascular repair of complex aortic aneurysms

ObjectiveThe ideal mating stent for target vessel revascularization in fenestrated endovascular aneurysm repair (FEVAR) of juxtarenal and thoracoabdominal aortic aneurysms remains unknown. The objective of this study was to assess the outcomes associated with use of different stent types and configurations mated with reinforced fenestrations during FEVAR. MethodsClinical data from patients undergoing FEVAR for juxtarenal and thoracoabdominal aortic aneurysms in a prospective physician-sponsored investigational device exemption trial were analyzed. Outcomes for two different balloon-expandable covered stents (BECSs) mated with reinforced fenestrations were assessed along with the impact of distal extension with a self-expanding stent (SES). Primary patency, branch-related endoleak, and reintervention rates were determined. Cox proportional hazards model was used for time-to-event analysis. ResultsFrom 2001 to 2016, there were 918 patients who underwent fenestrated or branched endograft repair of complex aortic aneurysms; 1604 renal arteries (RAs), 714 superior mesenteric arteries (SMAs), and 333 celiac arteries (CAs) were mated with reinforced fenestrations using JOMED (n = 2014; Abbott Vascular, Santa Clara, Calif) or iCAST (n = 637; Atrium Medical, Hudson, NH) BECSs. The type of BECS did not affect short-term or long-term patency, branch-related endoleaks, or reintervention rates in the RA, SMA, or CA. Twenty-five percent (402/1604) of RAs, 84% (598/714) of SMAs, and 8% (27/333) of CAs underwent distal SES extension at the index operation. RAs with a distal SES in addition to the BECS had a higher likelihood of an occlusion event (hazard ratio, 2.791; 95% confidence interval, 1.42-5.48; P = .003) and reinterventions (P = .036) compared with those without an SES. Addition of a distal SES to the BECS in the SMA or CA did not have an impact on patency or reintervention rates. ConclusionsBECS choice does not appear to have an impact on branch durability after FEVAR. Selective distal SES placement in RAs with high-risk anatomy does not appear to significantly protect against an occlusion event or to prevent secondary interventions. Routine addition of a distal SES does not improve SMA fenestration durability.

Midterm Results of the Treatment of Penetrating Abdominal Aortic or Iliac Artery Ulcer with the BeGraft Balloon-Expandable Covered Stent—A Single-Center Experience

The purpose of the study was to evaluate the feasibility and efficacy of the novel BeGraft covered stent for the treatment of abdominal penetrating aortic ulcer (PAU) or penetrating ulcers of the iliac arteries (PUIAs). This was a single-center observational study, which included 24 consecutive patients who underwent endovascular surgery due to abdominal PAU or PUIA between June 2017 and September 2019. Demographics of patients, lesion characteristics, diameter and length of the BeGraft stents, and postoperative events were prospectively collected and retrospectively analyzed. Follow-up examinations were performed at 1, 6, 12, and 24months with clinical and hemodynamic evaluation. Outcome measures included technical success, perioperative complications, and stent patency. A total of 24 patients (13 men and 11 women), with a median age of 67years (range, 42-81years), were analyzed. Among them, 20 patients were symptomatic, and 4 patients underwent elective surgery because of the size of PAU. A total of 54 BeGraft stents (26 aortic and 28 peripheral) were successfully delivered and deployed to cover 13 aortic and 13 common iliac artery ulcer lesions. The technical success rate was 100%. The average procedural time was 53.8±12.8min. Complications included one case of the access-site pseudoaneurysm, which was successfully treated by thrombin injection. During a median follow-up of 20.5months (range, 6-33months), all stents remained patent, without endoleak or ulcer recurrence. BeGraft stents used during endovascular treatment of abdominal PAU and PUIA lesions are associated with favorable outcomes regarding technical success and patency. The primary use of BeGraft covered stents provides a valid option for patients with abdominal PAU. Long-term follow-up is required to confirm these promising results.

Novel Approach to Treatment of Chronic Iliocaval Occlusion Utilizing Covered Stents

Chronic iliocaval obstruction is a challenging clinical entity to treat. Endovenous iliocaval stenting is becoming the treatment of choice for central vein stenosis and occlusion. However, outcomes in thrombotic disease have not been as robust as nonthrombotic disease. In this article, we describe our experience utilizing covered stents as a novel tool for chronic total occlusions of the iliocaval veins. We performed a retrospective review of a prospectively maintained database of all patients undergoing endovenous stenting with a covered stent for chronic occlusive iliocaval disease over a 3-year period at our institution. Patients were followed clinically and with venous duplexes to assess the feasibility, safety, and outcomes of iliocaval endovenous stenting with covered stents. A total of 10 patients (8 men and 2 women) underwent iliocaval stenting with covered stents from July 2015 to May 2018. A total of 20 self-expanding covered stents (SECS) and 13 balloon expandable covered stents (BECS) were deployed in the central veins of the 10 patients. Six SECS and 5 BECS were deployed in the inferior vena cava, 10 SECS and 6 BECS were deployed in the common iliac veins (CIVs) (5 patients had bilateral CIV BECS and 2 patients had bilateral CIV SECS), and 4 SECS and 2 BECS were deployed in the external iliac veins (2 patients had bilateral SECS placed). Median follow-up time was 12.1 (range 0.5-35.0) months. There were no perioperative or postoperative complications. Nine (90%) patients maintained primary stent patency during our follow-up time. One patient (10%) had rethrombosis of his stent due to undertreated common femoral vein disease in the setting of a new myeloproliferative neoplasm and an inappropriate cessation of therapeutic anticoagulation. All patients who were symptomatic preoperatively had improvement in their pain, venous ulceration, and venous claudication. Eight of nine (89%) patients had improvement in their lower extremity edema. Covered endovenous stenting of chronically occluded central veins is a safe and promising procedure. Their use may improve the short- and long-term outcomes in this challenging patient population. Further studies are required to evaluate the long-term efficacy and cost of their use.

In Vitro Evaluation of Balloon-Expandable Chimney Grafts in the Renal Arteries Combined With the Endurant Endograft

Purpose: To compare balloon-expandable covered stents (BECS) available for use as renal chimney grafts to the Advanta V12 approved for use with the Endurant endograft. Materials and Methods: A silicone model was manufactured based on preoperative computed tomography angiography (CTA) scans of a patient with a 7-cm juxtarenal aneurysm treated with an Endurant bifurcated endograft and an Advanta V12 covered stent for the 6-mm-diameter right renal artery. The model was placed in a flow box filled with a 37°C blood-mimicking solution equipped with a pulsatile pumping system (140/60 mm Hg). The tested BECS were the Advanta V12, the VBX, and the BeGraft+. A 36-mm-diameter Endurant II endograft with a 16-mm-diameter contralateral limb and a 6×59-mm BECS chimney graft were used in 9 consecutive tests (3 for each combination). After each implantation, the model was placed in the CT scanner, and 2 radiologists blinded to the test device independently measured the gutter areas and the patent chimney graft lumen at the level of the Endurant’s suprarenal stent, at the level of the chimney’s maximum curvature, and 10 mm inside the renal artery. The intraclass correlation coefficients (ICC) were calculated to assess interreader reliability. Results: The mean gutter areas were 19.3±7, 20.2±8, and 22.3±8 mm2 for the Advanta, VBX, and BeGraft+, respectively (all p>0.05). At the level of the aortic endograft’s suprarenal stent struts, the mean diameter of the Advanta V12, VBX, and BeGraft+ were 4.46±0.3, 4.12±0.4, and 4.12±0.3 mm, respectively (all p>0.05). At the level of the maximum chimney graft angulation, the mean diameters were 3.77±0.3, 4.16±0.1, and 3.74±0.3 mm, respectively (all p>0.05). In the right renal artery, the mean diameters were 3.91±0.2, 4.05±0.9, and 4.3±0.4 mm, respectively (all p>0.05). The ICCs varied between 0.7 and 0.9, indicating good agreement between readers. Conclusion: These in vitro findings showed comparable results between the Advanta V12 and the available BECS used in conjunction with the Endurant endograft according to the instructions for use. Further clinical evaluation is needed to confirm these results.

Covered stents versus Bare-metal stents in chronic atherosclerotic Gastrointestinal Ischemia (CoBaGI): study protocol for a randomized controlled trial

BackgroundChronic mesenteric ischemia (CMI) is the result of insufficient blood supply to the gastrointestinal tract and is caused by atherosclerotic stenosis of one or more mesenteric arteries in > 90% of cases. Revascularization therapy is indicated in patients with a diagnosis of atherosclerotic CMI to relieve symptoms and to prevent acute-on-chronic mesenteric ischemia, which is associated with high morbidity and mortality. Endovascular therapy has rapidly evolved and has replaced surgery as the first choice of treatment in CMI. Bare-metal stents (BMS) are standard care currently, although retrospective studies suggested significantly higher patency rates for covered stents (CS). The Covered stents versus Bare-metal stents in chronic atherosclerotic Gastrointestinal Ischemia (CoBaGI) trial is designed to prospectively assess the patency of CS versus BMS in patients with atherosclerotic CMI.Methods/designThe CoBaGI trial is a randomized controlled, parallel-group, patient- and investigator-blinded, superiority, multicenter trial conducted in six centers of the Dutch Mesenteric Ischemia Study group (DMIS). Eighty-four patients with a consensus diagnosis of atherosclerotic CMI are 1:1 randomized to either a balloon-expandable BMS (Palmaz Blue with rapid-exchange delivery system, Cordis Corporation, Bridgewater, NJ, USA) or a balloon-expandable CS (Advanta V12 over-the-wire, Atrium Maquet Getinge Group, Hudson, NH, USA). The primary endpoint is the primary stent-patency rate at 24 months assessed with CT angiography. Secondary endpoints are primary stent patency at 6 and 12 months and secondary patency rates, freedom from restenosis, freedom from symptom recurrence, freedom from re-intervention, quality of life according the EQ-5D-5 L and SF-36 and cost-effectiveness at 6, 12 and 24 months.DiscussionThe CoBaGI trial is designed to assess the patency rates of CS versus BMS in patients treated for CMI caused by atherosclerotic mesenteric stenosis. Furthermore, the CoBaGI trial should provide insights in the quality of life of these patients before and after stenting and its cost-effectiveness. The CoBaGI trial is the first randomized controlled trial performed in CMI caused by atherosclerotic mesenteric artery stenosis.Trial registrationClinicalTrials.gov, ID: NCT02428582. Registered on 29 April 2015.

Identification of optimal device combinations for the chimney endovascular aneurysm repair technique within the PERICLES registry

ObjectiveThe ideal stent combination for chimney endovascular aneurysm repair remains undetermined. Therefore, we sought to identify optimal aortic and chimney stent combinations that are associated with the best outcomes by analyzing the worldwide collected experience in the PERformance of chImney technique for the treatment of Complex aortic pathoLogiES (PERICLES) registry. MethodsThe PERICLES registry was reviewed for patients with pararenal aortic disease electively treated from 2008 to 2014. Eleven different aortic devices were identified with three distinct subgroups: group A (n = 224), nitinol/polyester; group B (n = 105), stainless steel/polyester; and group C (n = 69), nitinol/expanded polytetrafluoroethylene. The various chimney stent subtypes included the balloon-expandable covered stent (BECS), self-expanding covered stent, and bare-metal stent. Deidentified aortic and chimney device combinations were compared for risk of chimney occlusion, type IA endoleak, and survival. Effects of high-volume centers (>100 cases), use of an internal lining chimney stent, number of chimney stents, and number of chimney stent subtypes deployed were also considered. We considered demographics, comorbidities, and aortic anatomic features as potential confounders in all models. ResultsThe 1- and 3-year freedom from BECS chimney occlusion was not different between groups (group A, 96% ± 2% and 87% ± 5%; groups B and C, 93% ± 3% and 76% ± 10%; Cox model, P = .33). Similarly, when non-BECS chimney stents were used, no difference in occlusion risk was noted for the three aortic device groupings; however, group C patients receiving BECS did have a trend toward higher occlusion risk relative to group C patients not receiving a BECS chimney stent (hazard ratio [HR], 4.0; 95% confidence interval [CI], 0.85-18.84; P = .08). Patients receiving multiple chimney stents, irrespective of stent subtype, had a 1.8-fold increased risk of occlusion for each additional stent (HR, 1.8; 95% CI, 1.2-2.9; P = .01). Use of a bare-metal endolining stent doubled the occlusion hazard (HR, 2.1; 95% CI, 1.0-4.5; P = .05). Risk of type IA endoleak (intraoperatively and postoperatively) did not significantly differ for the aortic devices with BECS use; however, group C patients had higher risk relative to groups A/B without BECS (C vs B: odds ratio [OR], 3.2 [95% CI, 1-11; P = .05]; C vs A/B: OR, 2.4 [95% CI, 0.9-6.4; P = .08]). Patients treated at high-volume centers had significantly lower odds for development of type IA endoleak (OR, 0.2; 95% CI, 0.1-0.7; P = .01) irrespective of aortic or chimney device combination. Mortality risk was significantly higher in group C + BECS vs group A + BECS (HR, 5.3; 95% CI, 1.6-17.5; P = .006). The 1- and 3-year survival for groups A, B, and C (+BECS) was as follows: group A, 97% ± 1% and 92% ± 3%; group B, 93% ± 3% and 83% ± 7%; and group C, 84% ± 7% and 63% ± 14%. Use of more than one chimney subtype was associated with increased mortality (HR, 3.2; 95% CI, 1.4-7.5; P = .006). ConclusionsWithin the PERICLES registry, use of nitinol/polyester stent graft devices with BECS during chimney endovascular aneurysm repair is associated with improved survival compared with other aortic endografts. However, this advantage was not observed for non-BECS repairs. Repairs incorporating multiple chimney subtypes were also associated with increased mortality risk. Importantly, increasing chimney stent number and bare-metal endolining stents increase chimney occlusion risk, whereas patients treated at low-volume centers have higher risk of type IA endoleak.

Preliminary Outcomes of the LifeStream Balloon-Expandable Covered Stent in Fenestrated and Branched Thoracoabdominal Endovascular Repairs

Purpose: To evaluate the 1-year outcomes of thoracoabdominal aortic aneurysm (TAAA) repair using fenestrated and branched stent-grafts and a novel balloon-expandable covered stent. Methods: Between March 2015 and January 2017, 18 patients (median age 74.7 years; 14 men) received 43 LifeStream balloon-expandable covered stents in conjunction with Zenith fenestrated/branched stent-grafts to bridge 11 celiac trunks, 8 superior mesenteric arteries, and 24 renal arteries (total 32 fenestrations and 11 branches). Results: Stent delivery and deployment was successful in all cases. At 30 days, 5 patients presented with perifenestration endoleaks (type IIIc) secondary to inadequate sealing of the LifeStream covered stent in 7 (22%) of 32 fenestrations. No type IIIc endoleaks were reported in the branched cases. Four patients had a secondary endovascular reintervention with proximal relining by means of a bare balloon-expandable stent at the perifenestration transition area, with complete resolution of the endoleak at 1-year follow-up. One patient refused reintervention. The last 4 fenestrated stent-grafts of this series had prophylactic perifenestration bare stent relining with no evidence of type IIIc endoleaks at imaging. At a median follow-up of 14.1 months (interquartile range 11, 22), the 12-month LifeStream patency rate was 100%. Conclusion: This single-center preliminary experience with the LifeStream balloon-expandable covered stent in fenestrated/branched stent-grafts for TAAA repairs demonstrated good patency; however, an unexpectedly high rate of type IIIc endoleaks was observed. These endoleaks were resolved with reintervention or during the index procedure by proximal relining with a bare balloon-expandable stent, achieving adequate perifenestration sealing.

Endovascular Treatment of Occlusive Lesions in the Aortic Bifurcation with Kissing Polytetrafluoroethylene-Covered Stents

PurposeTo determine the clinical outcomes of polytetrafluoroethylene covered balloon expandable stents (CBESs) in occlusive lesions of the aortic bifurcation in a kissing stent configuration. Materials and MethodsThe study included 69 consecutive patients (29 men, 40 women) who underwent kissing stent procedures with CBESs between January 2003 and April 2009 in a single center. Patients who were previously treated with a CBES were excluded. Follow-up consisted of clinical investigation and duplex ultrasound examination. ResultsThe primary patency was 88.1% at 1 year and 71.5% at 4 years, with secondary patency rates of 88.1% and 75.3%, respectively. For patients receiving a stent for the first time, primary patency was 91.3% at 1 year and 77.1% at 4 years. For patients who had received previous stents, patency was 83.6% at 1 year and 65.2% at 4 years (P = .83). There were no differences in secondary patency and freedom from target lesion reintervention (TLR). Loss of primary patency was mainly caused by stent occlusions (14 cases [78%]). The freedom from TLR at 4 years was 76.8%. ConclusionsPatency rates and freedom from TLR of CBESs in the kissing stent configuration with up to 4 years of follow-up were satisfying and mainly affected by stent occlusions. Studies focusing on optimizing stent configuration and medical care to reduce the incidence of thrombosis are indicated to improve results further.

Covered stents for endovascular repair of iatrogenic injuries of iliac and femoral arteries.

The growing number of complex endovascular procedures is expected to increase the risk of iatrogenic injuries of peripheral arteries. A strategy of percutaneous transluminal angioplasty (PTA) with covered stent (CS) may represent a valuable alternative to open surgery. However, systematic evaluations of CS in this setting represent a scientific gap. In the present study, we investigate the procedural and clinical outcomes associated with PTA and CS implantation to repair iatrogenic injuries of peripheral arteries. All patients undergoing PTA with CS for endovascular repair of iatrogenic injuries of peripheral arteries between August 2010 and July 2013 at our Institution were retrospectively analyzed. The primary endpoint was the technical success. Secondary endpoints were in-hospital mortality and cumulative death, target lesion revascularization (TLR), amputation and major stroke at 12-month follow-up. During the period of observation, a total of 30 patients underwent PTA with either self-expandable (43.3%) or balloon-expandable CS (56.7%) for iatrogenic injuries of peripheral arteries. Injuries consisted of perforation/rupture (76.7%), arteriovenous fistula (16.7%) and pseudoaneurysm (6.7%) of iliac-femoral arteries. Technical success was achieved in all cases. Median follow-up was 409days [210-907]. The incidence of in-hospital mortality was 10.0%. At 12-month follow-up, the incidence of death, TLR, amputation and major stroke was 20.0%, 17.0%, 3.3% and 6.7%, respectively. The use of covered stents for endovascular repair of iatrogenic injuries of peripheral arteries shows a high technical success and may be alternative to surgery. Further studies with larger populations are needed to confirm these preliminary findings.

Polytetrafluoroethylene Covered Stent Placement for Focal Occlusive Disease of the Infrarenal Aorta

Arterial insufficiency is rarely caused by isolated infrarenal aortic occlusive lesions. Endovascular treatment options include plain balloon angioplasty and bare metal stent placement. In this study the feasibility and efficacy of polytetrafluoroethylene (PTFE) covered balloon expandable stents were evaluated. Consecutive patients from two centers were prospectively collected in a database and retrospectively analyzed. Results were evaluated by clinical examination, ankle-brachial indices (ABI), duplex ultrasound, and plain abdominal radiography. Thirty-six consecutive patients were treated between November 2008 and June 2013. Indication for treatment was Rutherford 3 (n = 29), 4 (n = 3), and 5 (n = 4). Technical success was always achieved and there were no distal embolizations or vessel wall ruptures. The median follow-up was 22 months (range 0–60). All patients improved clinically and the ABI increased significantly from 0.73 ± 0.18 to 1.01 ± 0.14 (p < .01). One patent covered stent was removed surgically because of infection. Primary patency rates were 100% at 1 and 2 years without stent fractures. The use of PTFE covered stents for the treatment of isolated infrarenal aortic occlusive disease is safe and very effective. Patency rates are excellent and complications including distal embolization and vessel wall rupture are extremely rare.