Balloon-expandable Stent Research Articles

Treatment of basilar artery stenosis with an Apollo balloon-expandable stent: a single-centre experience with 61 consecutive cases.

Stent placement for basilar artery (BA) stenosis remains a technical and clinical challenge. This retrospective study introduces the experience with the Apollo balloon-expandable stent (BES) for patients with symptomatic BA stenosis in a single centre in China. Sixty one patients who had undergone intervention for severe symptomatic BA stenosis between May 2012 and September 2018 were enrolled in this study. All patients underwent angioplasty and stenting with an Apollo BES and were followed-up continuously. The technical success rate was 100%. During the procedure, there was no vessel rupture or dissection. Two patients died due to perforator occlusion. One patient developed vasospasm with no symptoms. The rate of complications during the procedure was 4.91% (3/61). BA stent-related stroke or death rates were 4.9% at 30days (3/61), 6.6% at 3months (4/61), and 6.6% (4/61) at 6months. One patient had stent occlusion at 6months with no symptoms. Restenosis was found in five patients with degrees of restenosis greater than ≥ 50% without any symptoms. In this study, the Apollo BES appeared to be feasible for BA stenosis. Our experience may be valuable for reducing the number of complications. However, further study is needed.

Comparison of the Biomechanical Properties of the Advanta V12/iCast and Viabahn Stent-Grafts as Bridging Devices in Fenestrated Endografts: An In Vitro Study

Purpose: To compare experimentally the biomechanical properties of the Viabahn Balloon-Expandable Stent Graft (VBX) with the widely used Advanta V12/iCast in the role of bridging stent-grafts for fenestrated endovascular aortic repair. Materials and Methods: Test sheets made of polyester having 2 rows of 5 fenestrations in 6-mm and 8-mm diameters were used to simulate a commercially made fenestrated aortic endograft. In total, 40 stent-grafts measuring 6×39 mm and 8×39 mm (10 of each size for each stent-graft) were implanted in fenestration sheets immersed in a 37°C water bath. After flaring, all stent-grafts were evaluated using microscopy and radiography. Biomechanical evaluation included pullout and the shear stress force testing; results are reported in Newtons (N) as the median (minimum–maximum). Results: After flaring, no damage or fracture to the stent-graft structures were detected. Pullout forces for the 6-mm stent-grafts were 27.1 N (20.0–28.9) for the VBX and 16.6 N (14.7–19.2) for the Advanta (p=0.008). Pullout forces for the 8-mm stent-grafts were 20.1 N (14.8–21.5) for the VBX and 15.8 N (12.4–17.5) for the Advanta (p=0.095). The shear stress forces necessary to dislocate the device at 150% stent diameter displacement was 12.5 N (VBX) vs 14.7 N (Advanta) for the 6-mm devices and 23.3 N (VBX) vs 20.2 N (Advanta) for the 8-mm stents (p>0.99 and p=0.222, respectively). Conclusion: In vitro tests simulating external pull and shear forces on bridging stent-grafts implanted in fenestrations showed that the VBX had resistance to dislocation equivalent to a well-known control device.

Abstract No. 455 Customized patient-specific three-dimensional printed pediatric renovascular phantom for complex renal artery stenosis preprocedural planning: “plug and play”

The renal artery ostial anatomy, balloon profile and stent deployment are all elements of complex procedural RAS planning in children. This study aims to establish the feasibility of performing simulated renovascular intervention on a 3D printed pediatric RAS endovascular phantom. The first iteration of this phantom contained a normal nonremovable renovascular system. This iteration is upgraded to a removable patient tailored specific RAS “plug and play” module facilitating pre procedure planning. Silicone poured in 3D printed molds were created from the patient’s CT. An additional upper extremity vascular access point was added and a pump was installed to simulate circulatory flow. Models: patient- specific left inferior branch high-grade RAS (80%) and bilateral RAS (63% and 45%) with steep ostial angle Simulation steps: catheter and balloon entry via upper and lower extremity, selective renal angiography, stenosis identification and transgression, cutting balloon angioplasty and balloon expandable stent simulation. Operators completed a 10 point questionnaire, rating their experience using a 5-point Likert scale (1-Strongly disagree to 5-Strongly agree). Upper extremity approach was deemed necessary for selective renal catheterization due to the steep renal artery ostial angulation. Case 1: Left proximal RAS stenting was performed using 5 x 8 mm and 5 x 15 mm Viabahn balloon-expandable stents. Case 2: Right RAS (45%) 3x10 mm cutting balloon angioplasty followed by placement of a 3 x 8 mm balloon-expandable stent. Significant angiographic improvement was noted post procedure in both cases. Three operators had good agreement (k = 0.46) that the 3D printed phantom is helpful in procedure planning, skill development and provides a realistic experience from catheterization to stenting. The simulation resulted in a planned live patient brachial access. To our knowledge this is the first pediatric renovascular phantom using a patient-specific removable model. This platform can provide patient focused simulation for renal arterial approach, balloon stricture negotiation, stent sizing and deployment, all complex elements of this procedure in children.

How a new strain transformable titanium-based biomedical alloy can be designed for balloon expendable stents

Although largely used for numerous medical devices, the current titanium medical grades are not adapted for the manufacture of balloon expandable vascular stents due to their low plastic deformation abilities compared to stainless steels and cobalt-chromium alloys. In this study, a new biocompatible Ti-16Nb-8Mo alloy (wt.%) was designed with the objective to obtain large ductility and high strain hardening. In the alloy, a massive twinning and strain-induced martensitic transformation were observed to accommodate the plastic deformation leading to a very large plastic deformation since more than 45% of elongation at fracture were reached by tensile test. This huge plasticity, unusual for titanium alloys, is due to a complex deformation mechanism implying TWinning Induced Plasticity (TWIP) and Transformation Induced Platicicy (TRIP) effects, which were particularly investigated in such strain transformable alloy by electron backscattering diffraction (EBSD), by transmission electron microscopy (TEM) and by in-situ tensile test under synchrotron beam (SXRD).

Inferior Vena Cava Reconstruction in Symptomatic Patients Using Palmaz Stents: A Retrospective Single-Center Experience

The use of stents for treating central venous occlusion is well described. Limited evidence exists related to Palmaz balloon-expandable stent use in inferior vena cava (IVC) reconstruction. We analyzed patency and complication rates after IVC reconstruction using Palmaz stents. From 2002 to 2019, 37 patients (mean age: 51year) underwent IVC reconstruction with 68 Palmaz stents. Indications were symptomatic chronic venous obstruction in the infrarenal (n=25) and intrahepatic (n=12) IVC. Demographic, operative, and imaging data were evaluated. Clinical data, abdominal CT, and/or duplex ultrasound were used to determine patency at follow-up. Restoration of caval patency was achieved in all patients, with complications in 2/37 (5.4%) patients (thrombus formation within the stent; stent embolization eight days after placement). Follow-up data were available for 27 patients. Primary patency was maintained through last follow-up in 19/27 (70%) patients (mean: 1.1year), with successful stent redilation performed in 6 patients. Mean duration of primary-assisted patency (n=5) was 1.2year. Late lumen loss was (n=13) was 40% during a mean time to follow-up of 2.0years. Primary patency in patients with occlusion secondary to malignancy was 109day (range: 1 day-1.0year), whereas primary patency in patients with occlusion from other etiologies was 1.1year (range: 2day-5.9year). The Kaplan-Meier analysis demonstrated primary and primary-assisted patency of 66% and 84%, respectively, at 24 and 48 months. Palmaz balloon-expandable stents for IVC reconstruction is feasible and effective for symptomatic IVC occlusion. Risk of stent migration was low.

Mid-term results of in situ fenestration stented with balloon-expandable bare metal stents during thoracic endovascular aortic repair.

To assess the safety, feasibility and effectiveness of balloon-expandable bare metal stents (BMS) as bridge stents during thoracic endovascular aortic repair (TEVAR). Retrospective analysis was conducted on 103 consecutive patients who underwent TEVAR procedures from December 2015 to March 2018. Thirty-one patients fulfilled requirements for inclusion and exclusion in the analysis. Thirty-three in situ fenestration (ISF) procedures (single fenestration [n = 29]; dual fenestration [n = 2]) were performed in the 31 patients (67.7% men; median age, 61.5 year) who underwent TEVAR for thoracic lesions (aortic dissection [n = 23], aortic aneurysm [n = 3], aortic ulcer [n = 5]) with 34 stents (33 balloon-expandable BMS, 1 covered stents) implanted in supraaortic arteries. The success rate of overall intervention, fenestration, and implantation of BMS was recorded. The therapeutic effects and complications during admission and follow-up (median 29.7 months, range 18-45 months) were the primary outcomes. The technical success rate was 90.3% (28/31). All thoracic lesions were totally excluded. Major complications (6.5%) were one dissection in the left subclavian artery (n = 1) and thrombus formation (n = 1). Minor complications (12.9%) were hematoma (n = 1), and type III endoleak (n = 3). During follow-up, no endoleak developed and all fenestrated branch arteries were patent, except for one left subclavian artery dissection and occlusion. Use of balloon-expandable BMS in ISF is safe and effective in reconstruction of supraarotic arteries during TEVAR.

From the Aortic Bifurcation to the Groin: Long-term Outcomes of Covered Kissing Stent Placement in Combination with Iliofemoral Reconstruction for Extensive Iliofemoral Occlusive Disease

The aim of this study was to evaluate outcomes of extensive iliofemoral reconstruction combining both iliac covered kissing stents (ICKS) with stenting of the external iliac artery (SEIA) and/or surgical femoral endarterectomy (SFE). From November 2010 to November 2017, patients with extensive iliofemoral occlusive disease-classified as Trans-Atlantic Inter-Society Consensus class D-treated by ICKS in combination with SEIA and/or SFE were included. Patients received ICKS+SEIA, ICKS+SFE, or ICKS+SEIA+SFE. Demographics, procedure details, and postoperative outcomes were recorded. Primary end points were primary patency (PP), primary assisted patency (PAP), and secondary patency (SP). Long-term patency was assessed by annual clinical and ultrasonographic examination. Among 156 consecutive ICKS procedures performed during the study period, 59 patients were included (81% men; median age, 65years). In all, 32 patients (54%) underwent ICKS+SEIA, 17 (29%) patients underwent ICKS+SFE, and 10 (17%) patients underwent ICKS+SEIA+SFE. Operative indication was either disabling claudication (n=46, 78%) or critical limb-threatening ischemia (n=13, 22%). A total of 92 limbs were revascularized, including 121 covered balloon-expandable stents and 65 self-expanding nitinol stents, with 100% technical success. Thirty-day mortality was 3% (2/59) and 5 (8%) patients suffered from local complications, with no early reintervention. Long-term patency rates were as follows: at 2years, overall PP, PAP, and SP were 82%, 86%, and 96%, respectively; at 5years, overall PP, PAP, and SP were 73%, 79%, and 95%, respectively. After a mean follow-up of 34±29months, 25% (15/59) patients underwent late reinterventions for either de novo iliac or femoral stenosis (n=9), iliac occlusion (n=4), or external iliac in-stent restenosis (n=2). Treatment of extensive iliofemoral occlusive disease involving ICKS in combination with SEIA and/or SFE is safe and effective, providing satisfactory long-term secondary patency, at the price of a significant reintervention rate.

Outcomes of bridging stent grafts in fenestrated and branched endovascular aortic repair

ObjectiveUntil today, no dedicated bridging stent graft (BSG) has been available for use in fenestrated and branched endovascular aneurysm repair (F/BEVAR). The purpose of this study was to evaluate the clinical performance of the well-known Advanta/iCast V12 (Getinge Maquet, Rastatt, Germany) and the new Viabahn VBX (W. L. Gore & Associates, Flagstaff, Ariz) balloon-expandable stent graft in F/BEVAR. MethodsRetrospective analysis of prospectively collected data was performed. Inclusion criteria were treatment with fenestrated or branched endografts for complex aortic diseases, implantation of at least one VBX stent graft as a BSG in one of the target vessels, and clinical or radiologic follow-up of 6 months. The primary end point of the study was technical success of all BSGs, defined as placement of the BSG in the desired position with absence of endoleak on final angiography. Secondary end points were freedom from perioperative major adverse events and freedom from reinterventions and mortality at 6 months. Procedural and postoperative data were analyzed. ResultsBetween December 2017 and July 2018, there were 50 patients (40 male; mean age, 71 years) included. A total of 145 VBX stent grafts were implanted, followed by 57 Advanta V12, 29 Viabahn, and 28 bare-metal stents. There were 126 branches (celiac trunk, 27; superior mesenteric artery, 25; renal arteries, 74) sealed exclusively with VBX. Technical success rate was 98.6%. There were six device-related reinterventions due to type IC endoleaks (n = 4), target vessel stenosis distal to the BSG, and stent graft occlusion in a left renal artery in one case. The perioperative and aneurysm-related mortality was 0%; the 6-month all-cause mortality was 2%. ConclusionsThe used BSGs demonstrated promising preliminary results in F/BEVAR. Further evaluation is mandatory to determine durability of the VBX.

Transbrachial approach for successful recanalization and stenting of celiac artery

Mesenteric ischemia is an infrequent condition that presents either acutely or chronically. Endovascular treatment of mesenteric artery stenosis or short-segment occlusion by balloon dilation or stenting represents a less invasive therapeutic alternative to open surgical intervention, particularly in patients with comorbidities. We describe a case of ostio proximal celiac artery occlusion that was treated using balloon-expandable stent through the left brachial approach.

Primary patency and amputation free survival after endovascular management of infrarenal aorta total occlusions.

Endovascular therapy (EVT) has increasingly been used even after the development of new techniques and technologies. EVT has displayed durable early and mid-term outcomes for infrarenal aorta occlusions (IAO). Nonetheless, little is known regarding their long-term outcomes and predictors of restenosis. A total of 55 consecutive patients (age, 58.8±6.97 years; 67.2% male; 42% critical limb ischemia) from a single-center database, undergoing EVT for IAO disease between January 2011 and March 2019 were retrospectively analyzed. The outcome measures were primary patency rate and amputation free survival calculated by the Kaplan-Meier method. Independent predictors of restenosis were assessed by Cox proportional hazard regression model. In 49 patients (89.1%), technical success was achieved. In total, 190 stents (65 self-expandable stents, 60 balloon-expandable stents) were implanted. During the follow up of 34.5±28 months, 7 patients experienced loss of patency. Primary patency rates were 96%, 82%, and 75% at 1, 3, and 5 years, respectively, and amputation free survival rates were 100%, 90%, and 82% at 1, 3, and 5 years, respectively. In this study, five-year outcomes of primary patency and amputation free survival for EVT of infrarenal aorta total occlusive lesions were favorable. None of the demographic, lesion, and device factors were independently associated with loss of primary patency.

Late outcomes of different hypogastric stent grafts in aortoiliac endografting with iliac branch device: Results from the pELVIS Registry

ObjectiveThe objective of this study was to evaluate long-term results of self-expanding vs balloon-expandable hypogastric stent grafts in conjunction with iliac branch devices (IBDs) for aortoiliac aneurysm repair in a multicenter experience (pErformance of iLiac branch deVIces for aneurysmS involving the iliac bifurcation [pELVIS] Registry). MethodsAll patients electively treated for aortoiliac aneurysm with the Cook IBD (Cook Medical, Bloomington, Ind) in nine European centers were reviewed. Clinical and imaging data were prospectively collected in each center, and a multicenter database was created and interrogated. The primary outcome was the primary patency of the IBDs. For the purpose of this investigation, three subgroups were identified: patients receiving a hypogastric balloon-expandable stent graft (BESg); those with a self-expanding stent graft (SESg); and those with any stent graft plus relining with a bare-metal stent (RESg). ResultsBetween 2005 and 2017, there were 691 patients who underwent 747 elective endovascular repairs of aortoiliac aneurysms (n = 518 [75.0%]) or isolated iliac aneurysms (n = 173 [25.0%]) with Cook IBDs (n = 56 bilateral) in nine European centers. Mean age was 72 years (range, 41-93 years); 658 (95.2%) patients were male. In 364 patients (52.7%), BESg was used; in 127 (18.4%), SESg; and in 200 (28.9%), RESg. At 30 days, there were 3 (0.4%) perioperative deaths, 3 (0.4%) technical failures, 7 (1.0%) graft thromboses, 30 (4.3%) reinterventions, and 1 (0.1%) conversion to open repair. After a mean follow-up of 32 months (range, 0-128 months), 28 (3.7%) IBD occlusions and 17 (2.3%) IBD-related endoleaks occurred. In 10 patients, iliac diameter increased >5 mm (1.4%). Overall primary patency was 99.2% at 1 month, 97.9% at 12 months, and 95.1% at 72 months. Primary patency was not significantly different in the BESg vs SESg or RESg cohorts (P = .4). During follow-up, there were 126 (18.2%) reinterventions, 93 (13.5%) of which were IBD related, including 11 (1.6%) conversions. Overall, freedom from reintervention and conversion was 90.4% at 12 months and 71.0% at 72 months. IBD-related reinterventions during follow-up in the three cohorts were not significantly different (P = .3) Overall survival was 71.3% at 72 months without differences between the subgroups. At multivariate analysis, aneurysmal hypogastric artery (P < .001; Exp [B] = 4.44) and bilateral treatment (P = .02; Exp [B] = 1.87) were associated with an increase in late failure. ConclusionsIn this wide real-world experience, long-term results of endovascular treatment of aortoiliac aneurysms with the IBD are favorable, with a low rate of late graft occlusion and aneurysm-related death. No significant differences in clinical outcomes were observed in patients receiving hypogastric BESg vs SESg or endovascular relining.

Performance of Viabahn Balloon-Expandable Stent Compared With Self-expanding Covered Stents for Fenestrated-Branched Endovascular Aortic Repair

The objective of this study was to compare the performance between Viabahn (W. L. Gore & Associates, Flagstaff, Ariz) balloon-expandable stent (VBX) and self-expanding covered stents (SESs; Viabahn and Fluency [Bard Peripheral Vascular, Tempe, Ariz]) used as bridging stents for directional branches during fenestrated-branched endovascular aneurysm repair of complex aortic aneurysms. Patients with thoracoabdominal aortic aneurysms (type I-IV) or pararenal aortic aneurysms unsuitable for either open repair or endovascular repair with commercially available devices were prospectively enrolled into a physician-sponsored investigational device exemption trial. Descriptive statistics of the cohort included demographics, risk factors, and anatomic and device characteristics. Individual branches were grouped as either VBX or SES and were analyzed for primary patency, branch-related type I or type III endoleaks, branch instability, branch-related secondary intervention, and branch-related aortic rupture or death. Categorical variables were expressed as total and percentage and continuous variables as median (interquartile range). Kaplan-Meier curves were used to estimate long-term result. Groups were compared with the log-rank test. P value < .05 was considered statistically significant. During the period from July 2012 through April 2019, there were 263 patients treated for complex aortic aneurysm with fenestrated-branched endovascular aneurysm repair. The devices used were either a custom-manufactured device or off-the-shelf p-Branch or t-Branch devices (Cook Medical, Bloomington, Ind). The median age was 71 years (interquartile range, 66-79 years), 70% male, and 81% white. The most common cardiac risk factors were smoking (92%), hypertension (91%), hyperlipidemia (78%), and chronic obstructive pulmonary disease (52%). The total number of vessels incorporated to repair was 977, with branches representing 18.4% (179 branches). Among the 179 branches were 54 (30%) celiac artery, 56 (31%) superior mesenteric artery, 38 (21%) right renal artery, and 31 (18%) left renal artery. VBX and SES groups represented, respectively, 53% (n = 95) and 47% (n = 84) of the total (Fig).The overall cohort survival rate at 24 months was 78.5% ± 3%. There was no branch-related rupture or death. Primary patency at 24 months (VBX, 98.1%; SES, 98.6%; log-rank, P = .98), freedom from endoleak (VBX, 97.3%; SES, 98.6%; log-rank, P = .63), freedom from secondary intervention (VBX, 91.5%; SES, 95%; log-rank, P = .69), and freedom from branch instability (VBX, 95.5%; SES, 97.3%; log-rank, P = .72) were similar between groups (Fig 2). The initial experience with VBX stents demonstrated excellent primary patency and similarly low rates of branch-related complications and endoleaks, with no branch-related aortic rupture or death. Our results demonstrate that in high volume and experienced aortic center, the VBX stent is a safe and effective bridging stent option during branched endovascular aortic repair. Multicenter studies with longer follow-up are necessary to validate our initial results.Fig 2Freedom from branch instability (BI). CI, Confidence interval; SES, self-expanding covered stent; VBX, Viabahn balloon-expandable stent.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Future Balloon-Expandable Stents: High or Low-Strength Materials?

Recent progress in material science allows researchers to use novel materials with enhanced capabilities like optimum biodegradability, higher strength, and flexibility in the design of coronary stents. Considering the wide range of mechanical properties of existing and newfangled materials, finding the influence of variations in mechanical properties of stent materials is critical for developing a practical design. The sensitivity of stent functional characteristics to variations in its material plastic properties is obtained through FEM modeling. Balloon-expandable coronary stent designs: Absorb BVS, and Xience are examined for artificial and commercial polymeric, and metallic materials, respectively. Standard tests including (1) the crimping process followed by stent implantation in an atherosclerotic artery and (2) the three-point bending test, have been simulated according to ASTM standards. In Absorb BVS, materials with higher yield stress than PLLA have similar residual deflection and maximum bending force to PLLA, which is not the case for Xience stent and Co-Cr. Moreover, elevated yield stress significantly reduces stent flexibility only in Xience stent. For both stents, with different degree of influence, an increase in yield or ultimate stress improves stent radial strength and stiffness and reduces arterial stress and plastic strain of stent, which consequently enhances the stent mechanical performance. Contrarily, yield or ultimate stress elevation increases stent recoil which adversely affects stent performance. Using high-strength materials has a double-edged sword effect on the stent performance and existing uncertainty in the precise estimate of stent mechanical properties adversely affects the reliability of numerical models' predictions.

First Report of Peripheral Balloon-Expandable Stent Underexpansion Treated by Intravascular Lithotripsy

A 75-year-old man with a history of peripheral artery disease and bilateral iliofemoral stent implantation 2 years previously was referred to our center for recurrent claudication. Pre-therapeutic computed tomographic angiography identified severe right common iliac artery stent restenosis related

Type IIIB Endoleak Associated to an Iliac Branch Device Bridging Stent.

Introduction: Frequently during aortoiliac endovascular exclusion (EVAR), distal fixation at the external iliac artery is needed. Iliac branch devices allow preservation of antegrade flow to the hypogastric artery. These are more complex procedures compared to standard aorto-iliac aneurysm repairs since involve additional arteries, materials, manoeuvers and longer procedural time. In most cases, the procedure is safe and mid-term complications are rare. We report a rare case of an endoleak associated with an iliac branched device during EVAR. Methods: A 75-year-old man with a history of hypertension, dyslipidemia, and former smoker, was intervened by an endovascular exclusion of aorto-iliac aneurysms twenty months earlier. The abdominal aortic aneurysm size was 72 mm and right iliac aneurysm size was 30 mm. A suprarenal aortic stent graft (Zenith LP) and a right iliac branched device (ZBIS) were implanted. A balloon-expandable covered stent of 8x37 mm was used as a bridging stent. During the follow-up, computed tomography angiography (CTA) at 22 months showed a growth of the aneurysmal sac. Catheter angiography was performed, which demonstrated a type III endoleak secondary to stent rupture. Through an open axillary access, endovascular treatment was performed, implanting an overlapping 8x58 mm balloon expandable stent and 8x40 mm self-expanding stent.The completion angiography showed a technical success with a permeability of the endoprosthetic branch and absence of endoleaks. Results: During follow-up, a three-month ultrasound scan and a plain x-ray showed internal iliac branch patency, no stent fracture, and absence of endoleaks. Conclusion: Material related endoleaks associated to the exclusion of an abdominal aortic aneurysm are rare and in branched hypogastric devices, no case has been described. The occurrence of these late complications reinforces the need for post-operatory surveillance of these patients as well as the need to constantly improve the new materials being employed. In most cases, endovascular techniques allow their treatment through a minimally invasive approach with low morbidity.

The Kissing Stent Technique in the Treatment of Aorto-iliac TASC C-D Lesions: Clincal and Anatomical Predictors of Patency

Introduction - The endovascular treatment(EVT) of peripheral artery obstructive disease(PAOD) involving the aortic bifurcation is still a matter of debate in case of TASC-C and D lesions, since a complete revascularization of the entire aortic bifurcation is required. Aim of our work was to evaluate safety and efficacy of endovascular aortic bifurcation revascularization achieved with the kissing stent technique and analyze patency during the follow-up. Methods - All consecutive patients treated with aortic bifurcation kissing stenting (January 2012-December 2017) for aorto-iliac TASC-C and D PAOD were retrospectively analyzed. Anatomical features were reviewed at preoperative computed tomography angiography (CTA) to identify severe iliac calcifications (calcifications involving>75% of the circumferential diameter of the aorta and the common iliac arteries) and extensive aorto-iliac thrombosis (involving>75% of the aortic bifurcation diameter). Technical success(TS) was defined as the absence of>30% residual stenosis measured on angiographic images and other complications requiring reintervention. Primary(PP) and secondary(SP) patencies were analyzed during the follow-up performed by duplex ultrasound at discharge, 3, 6 months and yearly thereafter. Cox regression and Kaplan Meier analysis were performed to evaluate the long-term patency and possible risk factors. Results - Fifty-one(33.1%) patients fulfilled the inclusion criteria over a total of 154 aorto-iliac EVTs. Mean age was 66±1 years, 20(39.2%) were females. Risk factors: hypertension 94.1%, diabetes 41.1%, dyslipidemia 90.2%. Critical limb ischemia (Rutherford classification stages 4-6) was present in 22(43.1%) patients; 29(56.9%) had severe claudication (Rutherford 3). According to the preoperative CTA, TASC-C and D lesions were identified in 24(47%) and 27(53%) patients, and severe calcifications and extensive thrombosis in 55% and 45% of patients, respectively. Thirty-one patients(60.8%) received a dual antiplatelet therapy for at least 1 month after the procedure. TS was achieved in 49(96.1%) cases; in 2 patients, only one iliac axis was successfully revascularized due to technical reason, leaving the other surgically untreated. The kissing stenting technique was performed by balloon-expandable stent in 30(58.8%) cases, self-expandable stent in 12(23.5%) cases, and covered kissing stent in 9(17.6%) cases. In 28(54.9%) cases an extension of stenting in the external iliac artery was performed. At a mean follow-up of 38.5 months (1-78 range), PP and SP were 87±5% and 93±4%, respectively. Six iliac axis occluded during the follow-up, all within the first year after procedure and were revascularized in 3 cases(50%) with endovascular relining. Three other cases were left untreated due to the effective compensation achieved in the meantime. Among all the variables examined, only dual antiplatelet therapy delivery was associated with higher primary patency compared to single antiplatelet (96±4% vs 75±9%, P=.03), differentially severe aorto-iliac thrombosis was associated with lower primary patency (73±9 vs 96±4%, P=.03). The present results were confirmed also by Cox-regression analysis (HR: 0.14, 95%IC: 0.01-0.89, P=.05; HR: 6.8, 95%IC: 1.21-59, P=.05). Conclusion - EVT for aorto-iliac TASC C-D is an effective and safe technique. Iliac axis occlusion is rare and usually occurs within the first year after procedure in patients with no dual antiplatelet therapy. Severe preoperative thrombotic lesions are negative predictors of PP.

Prevalence of Subclavian Artery Stent Fractures and their Impact on Restenosis Development

Introduction - Stenting is the preferred, minimally invasive treatment for subclavian artery (SA) steno-occlusive disease. Stent fractures in the SA have not been assessed in large cohorts. Our aim was to determine the prevalence of SA stent fractures, identify predisposing factors, and analyse their impact on restenosis development. Methods - 120 patients (71 women; mean age: 59.4+/-9.0 years) with symptomatic significant SA stenosis who underwent stenting between 2002 and 2014 at our Department were included in the study. In 2016, patients were asked to return for a fluoroscopic examination of the implanted stents. Stent fractures were defined as type I: single-strut fracture, type II: > 2 strut fractures without deformation, type III: > 2 strut fractures with deformation, type IV: multiple strut fractures with acquired transection but without gap, and type V: multiple strut fractures with acquired transection with gap in the stent body. Colour duplex scan was used to monitor stent patency. In case of continuous variables t or Mann-Whitney U tests, while in case of categorical variables chi-square or Fisher exact tests were performed. Results - 122 stents were deployed (balloon-expandable, n = 94; self-expandable, n = 28). The median follow-up time was 81.4 (41.1-113.7) months. 43 (35.2%) stent fractures were detected (type I-II, n = 28; type III-V, n = 15). The difference between the fractured (n = 43) and non-fractured (n = 79) groups was non-significant regarding the atherosclerotic risk factors (age > 70 years, female sex, smoking, hypertension, hyperlipidemia, diabetes mellitus, obesity, chronic kidney disease), underlying pathology (atherosclerosis, restenosis, radiation-induced arteriopathy, vasculitis), lesion location, and stenosis grade. Calcifications, long lesions (> 20 mm), and long balloon-expandable stents (> 20 mm) were more common in the fractured than in the non-fractured groups (86.0% versus 43.0%, P < 0.001; 51.2% versus 20.3%, P < 0.001; 62.8% versus 40.5%, P = 0.036, respectively). The restenosis and reintervention rates were significantly higher in patients with type III-V fractures compared to those with type I-II fractures (60.0% versus 3.6%, P < 0.001; 46.7% versus 3.6%, P < 0.001, respectively). Conclusion - Fractures frequently occur. Lesion and stent characteristics have an influence on fracture rate. Complex fractures increase the risk of restenosis.

Chimney with the Use of Nellix Device: An Alternative Solution for Type I Endoleak Treatment

Introduction - Endovascular aortic repair with chimney technique (Ch-EVAR) is commonly used in the treatment of type I endoleak when the patient is unsuitable for conversion to open surgery or custom made endograft implantation. Main issue with chimney technique is related to gutter endoleak; this risk may be reduced with the use of a Nellix device (Ch-EVAS), that could fill the gutter and reduce the incidence of type I endoleak. Methods - Sixteen consecutive patients (mean age 80.7 ± 7.0 years; 94% men) with prior EVAR were treated with ChEVAS between August 2015 and March 2018 in a single center. Indication for treatment was proximal type I endoleak in all patients, with associated neck dilation in 5 patients and migration in 5. The median diameter of residual aneurismal sac was 79.1 ± 2.4 mm The median time between original procedure and ChEVAS was 92.7±5.3 (range 1-148) months. Prior EVARs included different endografts (5 Zenith, 3 Endurant, 4 Talent, 1 Anaconda, 1 Fortron and 2 Nellix). In 12 patients (75%) preoperative CT scan showed the presence of suprarenal stent at the level of the visceral vessels. Two patients needed one chimney, ten patients needed double chimney and four patients needed three chimneys for a total of 34 target vessel overstented. In 30 visceral vessels a balloon expandable stent (Advanta atrium or Bentley BeGraft) was implanted, in the remaining 4 vessels a self-expandable stent (Viabahn Gore) was delivered. The Nellix endograft was implanted by bilateral percutaneous femoral approach in 11 patients Results - Technical success was achieved in 100% of the patients by completion angiography at the end of the procedure. No perioperative mortality was observed, one patient experienced non disabling posterior stroke at the end of the procedure. CT scan performed 1 month after the procedure showed sealing of 15/16 (94%) of type I endoleak , the remaining patient with residual proximal endoleak underwent a successful Onyx embolization one month later. At median follow-up of 13 months no recurrent endoleaks were recorded. All target vessel stented were patent with no need of reintervention. Conclusion - ChEVAS may serve as alternative treatment option in patients with type I endoleak where the implantation of fEVAR/brEVAR is hampered by the presence of previous endograt in site. Further follow-up and a multicenter study are needed to corroborate these preliminary results

Prospective evaluation of drug eluting self-apposing stent for the treatment of unprotected left main coronary artery disease: 1-year results of the TRUNC study.

To assess long-term safety and efficacy of the Xposition S self-apposing stent in the treatment of unprotected left main coronary artery (ULMCA) disease. Percutaneous intervention with stents has emerged as a valid alternative to surgical revascularization to treat ULMCA disease. Conventional balloon-expandable stents face technical challenges, particularly in large left main diameter requiring extensive optimization and side branch access in distal bifurcation. Xposition S allows for optimal apposition, bridging diameter differences, and allows expansion to vessel diameters up to 6.0 mm. Between June 2016 and July 2017, 205 patients were enrolled in this international, prospective, multicenter registry. Patients with SYNTAX score ≥ 33 or recent STEMI were excluded. IVUS during procedure was performed in a prespecified subgroup of 50 patients. The primary clinical endpoint was 12 months Target lesion failure (TLF) and the primary efficacy endpoint was angiographic success. Distal left main bifurcation was involved in 92.7%, treated with provisional approach in most cases (79.4%). TLF rate at 12 months was 8.3%, which was defined as a composite of cardiac death (2.0%), target-vessel MI (2.9%), and TLR (5.4%). Most revascularizations occurred at SB ostium. IVUS analysis demonstrated optimal stent apposition with only one reported malapposition and promising poststenting minimal stent area measures. The TRUNC study confirms that Xposition S self-apposing stent is a valid and feasible option for the treatment of ULMCA disease. Such results were reached without the systematic need of stent optimisation techniques, focusing mainly on lesion treatment.

Stage 1 hybrid palliation of hypoplastic left heart syndrome: an initial experience in pulmonary trunk approach, procedural modifications, and complication management

Background/aimHypoplastic left heart syndrome (HLHS) is a rare pathology with a very high mortality rate. The present study aimed to share our initial experience with the ductus arteriosus stenting procedure using the pulmonary trunk approach in the treatment of HLHS, as well as provide some technical suggestions and discuss complications and their management.Materials and methodsThe medical records of 9 neonates (age range: 1–8 days) with HLHS, who were operated on within a 12-month period, were reviewed retrospectively. Preprocedural planning was performed by computed tomography angiography and echocardiography. The operations were performed in a hybrid surgery room by interventional radiologists and pediatric vascular surgeons. Balloon-expandable stents were used in all of the operations.ResultsAll operations were successfully completed without any intraoperative mortality. All intraoperative complications were managed successfully during the stenting procedure.ConclusionStage 1 hybrid palliation for HLHS is a safe and effective procedure when several key points are kept in mind.