Large Stent Research Articles

Intravascular lithotripsy-assisted intervention in patients with congenital heart disease.

The use of intravascular lithotripsy (IVL) in patients with calcified coronary and peripheral arterial disease is now commonplace; however, its use in procedures specific to congenital heart disease is rare, with a very limited published case-based experience to date. The authors report the outcomes of 4 patients with congenital heart disease who underwent IVL-assisted transcatheter procedures in the effort to inform future operators as to the potential benefits and risks of this technology in this patient population. Four patients underwent IVL-assisted transcatheter procedures including branch pulmonary artery stenting, aortic coarctation stenting, and transcatheter pulmonary valve replacement. All 4 patients underwent successful IVL-assisted implantation of large stents in highly calcified native or surgically implanted biological conduits without significant complications. The use of IVL-assisted interventions in patients with severe native or surgical calcified vascular conduits is feasible and may be a useful adjunct in conduit stent implantation and dilation. Vascular injury during angioplasty of calcified vessels and conduits remains a concern despite the use of lithotripsy, and covered stent implantation should be considered prior to aggressive dilation in order to reduce the risk of catastrophic rupture.

Luck in high-stakes firm lottery allocation: A natural experimental test of Coasean efficiency and invariance in a prominent sport finance setting

The NBA Player-Draft is a prominent sport-finance setting, with large rents allocated to teams. Several properties make this setting ideal to study the Coase Theorem in a cartelized-firm setting, where the Theorem’s empirical credence and overall relevance to real-world financial settings continue to be questioned. Identification of a high-stakes, salient setting featuring exogenously-assigned property rights has proven elusive. While several studies examine the Coasean implications of professional sports league drafts, we find draft rights are endogenously-assigned. We cultivate, verify, specify, and examine an exogenously-assigned draft right—draft lottery luck—for the 2000–2015 NBA Drafts. Given its revealed exogeneity, we utilize variation in annual lottery luck as a natural experiment to study the Coase Theorem and find robust evidence for “instantaneous” Coasean efficiency (as in efficiency of the efficient market hypothesis) but also evidence that Coasean invariance, with respect to firm profits, fails. Secondary analysis reveals respective mechanisms and sport-financial implications.

Efficacy of the Stripped AFX Aortic Cuff as a Scaffolding Bare Stent to Facilitate the Expansion of the Thoracoabdominal and Visceral Aorta during Thoracic Endovascular Aortic Repair for Complicated Stanford Type B Aortic Dissection.

During thoracic endovascular aortic repair for complicated Stanford type B aortic dissection, large bare stent placement for the abdominal aorta is sometimes necessary. In smaller abdominal aortic diameter cases, we used the stripped AFX aortic cuff as a scaffolding bare stent rather than the Zenith Dissection Endovascular Stent, which is a commercially available, large bare stent. In this study, we evaluated the feasibility of the stripped AFX aortic cuff and experiments were conducted to compare the stripped AFX and the Zenith Dissection Endovascular Stent. The type B aortic dissection patients treated with thoracic endovascular aortic repair using stripped AFX at three institutions between January 2014 and December 2017 were retrospectively reviewed. Clinical data, including technical success, perioperative complication, and overall survival, were evaluated. The experiment assessed the chronic outward force that reflected the load acting on the artery wall from the stent. Eight cases (seven males) were reviewed. The median (interquartile range, IQR) age of the patients was 60 years (46.3-70.3). The technical success rate was 100%, and no perioperative complications were observed. The median (IQR) follow-up period was 28.9 months (17.5-31.5). During the follow-up, one patient died of septic shock unrelated to aortic events. The median (IQR) diameter of the stripped AFX on the last follow-up CT was 23.5 mm (21.9-25.0). The chronic outward force of the Zenith Dissection Endovascular Stent was two to three times that of the stripped AFX. The stripped AFX aortic cuff is feasible and safe as a scaffolding stent during thoracic endovascular aortic repair for Stanford Type B aortic dissection.

Branch Thrombus after Endovascular Treatment with Arch Branched Devices for Aortic Arch Pathologies

The aim of this study was to describe the occurrence of branch thrombosis following endovascular treatment of aortic arch pathology using an arch branched device (ABD) and to determine whether this is influenced by clinical and geometric parameters. In this retrospective observational study of patients treated with an ABD in three centres, the primary endpoint was thrombus formation within a branch during follow up. Secondary endpoints were technical success, serious adverse events (SAEs), early and late death, stroke, and re-interventions. Geometric measurements (tortuosity index and curvature) were determined on pre-operative and post-operative computed tomography angiographies. Thirty nine patients were treated and 68 antegrade branches were analysed (innominate artery, n = 27; common carotid artery [CCA], n = 40; left subclavian artery [LSA], n = 1). Thrombus was identified within seven branches (10%) on surveillance imaging (innominate artery, n = 6; CCA, n = 1; LSA, n = 0; p = .021) and was associated with a wider distal bridging stent diameter (median 14.0 mm [interquartile range {IQR} 2.0] vs. 8.7 mm [IQR 5.9]; p = .026), a higher degree of reversed tapering (4.3 mm [IQR 1.4] vs. 1.2 mm [IQR 2.8]; p = .023), use of polyethylene terephthalate (Dacron) covered (vs. expanded polytetrafluoroethylene) bridging stents (23% vs. 2%; p = .011), and higher body mass index (BMI) (32.1 kg/m2 [IQR 7.5] vs. 25.7 kg/m2 [IQR 5.4]; p = .029), but not with pre-operative or post-operative tortuosity index or curvature or alterations. Regarding secondary outcomes, the technical success rate was 97%, SAEs occurred in 15 patients (38%), early and late death rates were 8% and 23%, respectively, and early and late stroke rates were 5% and 23%, respectively. The risk of developing branch thrombosis after endovascular intervention with an ABD is considerable, especially of innominate artery branches, characterised by Dacron covered large diameter bridging stents, and in patients with a high BMI. Large prospective studies are required to analyse factors associated with branch thrombosis.

Outcomes of endoscopic ultrasound-guided gallbladder drainage: A multicenter study from India (with video).

Endoscopic ultrasound-guided gallbladder drainage (EUS-GBD) offers a safe and minimally invasive alternative for percutaneous cholecystostomy (PCC) in acute cholecystitis patients with high-surgical risk. Additionally, EUS-GBD serves as a rescue biliary drainage in malignant distal biliary obstruction. Despite its widespread application, data within the Indian context remains sparse. This study aims to report the outcomes of EUS-GBD through the first multi-center study from India. We retrospectively analyzed patients undergoing EUS-GBD at six tertiary care centers of India from March 2022 to November 2023. EUS-GBD was performed by free hand or over-the-guidewire technique with lumen-apposing metal stent (LAMS) or large caliber metal stent (LCMS). The primary outcome was technical success (defined as successful deployment of stent between gallbladder and stomach/duodenal lumen). The secondary outcomes were clinical success (defined as resolution of symptoms of acute cholecystitis and more than > 50% reduction in bilirubin level within two weeks in distal biliary obstruction), adverse event rate, 30-day mortality rate and 90-day reintervention rate. Total29 patients (mean age 65.86 ± 12.91, 11 female) underwent EUS-GBD. The indication for EUS-GBD were acute cholecystitis (79.31%) and rescue biliary drainage for malignant distal biliary obstruction (20.69%). LAMS was deployed in 92.86%, predominantly by free-hand technique (78.57%). Technical and clinical success rates were 96.55% and 82.75%, respectively. Adverse events occurred in 27.59% patients, with severe adverse events (bile leak and bleeding) being uncommon (10%). Both 30-day mortality rate and 90-day reintervention rate were 13.79% in patients. Cholecysto-duodenal fistula facilitated cholecystoscopic intervention and stone removal in one patient and transgastric EUS-GBD did not hamper bilio-enteric anastomosis during Whipple surgery in two patients. EUS-GBD is a safe and effective technique for managing acute cholecystitis in high-risk patients and for biliary drainage in cases with malignant distal biliary obstruction.

Small Oversized Stent Graft Is Associated With Increased Patency for the Treatment of Central Venous Disease in Hemodialysis Patients.

The purpose of this study was to identify the independent predictors of higher patency rates and investigate the selection of specifications of stent graft in the treatment of central venous disease. This retrospective study included 54 patients who underwent stent-grafts' placement for the treatment of central venous disease between March 2017 and September 2022 at a tertiary hospital. The demographic data for the patients and the clinical data of the treated lesions were collected and analyzed. The patency rates of the treated lesions with different oversizing range were calculated via the Kaplan-Meier and log-rank analyses. The multivariate Cox proportional hazard models were constructed to identify the independent predictor of the target site primary patency. The median follow-up period was 21.5 months. The primary patency rates of the target sites were 90.7%, 72.2%, and 55.1% at 6, 12, and 24 months, respectively. The assisted primary patency rates of the lesions were 96.3%, 92.5%, and 80.3% at 6, 12, and 24 months, respectively. The log-rank analysis showed that the stent-grafts' placement with small oversizing had significantly higher primary patency rates than those with large oversizing (p=0.022). The multivariate analysis revealed that concomitant stenosis and large oversizing stent graft were the independent predictors of target site primary patency. Stent grafts showed reasonable primary patency for the treatment of central venous disease in hemodialysis patients. A stent graft with small oversizing is associated with better target site primary patency rates than those with large oversizing. Stent grafts showed reasonable primary patency for the treatment of central venous disease in hemodialysis patients. Few studies, however, have explored the efficiency of stent grafts to treat CVD by considering different factors such as sizing considerations, the rate of oversizing percentage, etc. A stent graft with small oversizing is associated with better target site primary patency rates than those with large oversizing. Excessive oversizing should be avoided to prevent infolding or stent collapse.

Off-label use of large bariatric stent: how to open the angle

Off-label use of large bariatric stent: how to open the angle

Editor's Choice -- Type IIIb Endoleaks: Fabric Perforations of Explanted New Generation Endoprostheses

To analyse explanted endografts (EGs) and describe fabric degradation responsible for type IIIb endoleaks. As part of the European collaborative retrieval programme, 32 EGs with fabric defects upon macroscopic evaluation were selected. The explanted EGs were processed and studied based on the ISO 9001 certified standard protocol. It includes instructions on the collection, transportation, cleaning, and examination of explanted material. The precise analysis was performed with a digital microscope of 20× - 200× magnification. Possible perforation mechanisms were assessed in stress tests. The median time to explantation of the 32 EGs was 54 months. The explants included 65 separate EG modules, with 46 (70.8%) having a combined 388 fabric perforations. Each EG had a median of 4.79 mm2 (interquartile range [IQR] 9.86 mm2) of cumulated hole area (an average of 0.13% of an EG's area). There were 241 (62.1%) expanded polytetrafluoroethylene (ePTFE; 12 EGs) and 147 (37.9%) polyethylene terephthalate (PET; 20 EGs) fabric ruptures, with no difference in hole distribution between these types of material. Overall, 126 (32.5%) stent related and 262 (67.5%) non-stent related fabric perforations were identified. Perforations caused by fabric fatigue in ePTFE (151, 38.9%) and material kinking in PET (41, 10.6%) were the most common. The stent related perforations were larger in size (0.80 mm2) than non-stent related (0.19 mm2); p = .004. Wider interstent spaces and prolonged implantation duration associated with an increased risk of stent related perforation development; p < .001, p = .004, respectively. Large stent related perforations were also detected in the short term, suggesting mechanical issues as underlying causes. The fabric of EGs may degrade and lead to the development of perforations. The largest perforations are stent related. Their occurrence and size depend on the implantation time and the EG shape affected by arterial tortuosity. The conclusions are limited to the samples from a select explant group.

A Case Report of Embolized Stent and Rashkind Septostomy that Suffer Hemolysis Due to Stent in 2-Days Neonate with Pulmonary Atresia and Single Ventricle

Introduction: Stenting in patent ductus arteriosus (PDA) and Rashkind septostomy in neonates with pulmonary atresia improves pulmonary and systemic venous blood mixing and oxygen saturation. In the present study, a case of embolized stent and Rashkind septostomy that suffered hemolysis due to the stent was reported in a 2-day neonate with pulmonary atresia and single ventricle. Case Presentation: The patient was a 2-day-old boy neonate with a gestational age of 35 ± 2 weeks and a birth weight of 2800 grams. Neonates' vital signs after birth were abnormal, and in the examination, cyanosis, tachypnea, grunting, and respiratory distress were observed. Auscultation had a systolic murmur at the left upper edge of the sternum. O2 saturation was about 70%, with a nasal oxygen intake of 3 L/min. Echocardiography confirmed the presence of pulmonary atresia and PDA. The initial treatment was done with prostaglandin E1, stenting in PDA, and a Rashkind septostomy. The neonate's cardiac arrest occurred during stenting, and the neonate was resuscitated. The angiography examination indicated PDA stent embolization in the pulmonary artery, and due to the unsuccessful restoration of the stent, a decision was made to use a larger stent in the PDA. The neonate suffered from hemolysis on the second day and was discharged with conservative treatment within 2 weeks with a good general condition. Conclusions: Keeping the PDA open with a proper stent and creating a Rashkind atrial septostomy improves the two-way mixing of pulmonary and systemic venous blood and oxygen saturation of neonates with pulmonary atresia and eliminates the need for surgery.

MP42-11 SILICONE STENTING FOR CHRONIC URETERAL OBSTRUCTION IMPROVES STENT EXCHANGE FREQUENCY

You have accessJournal of UrologyCME1 Apr 2023MP42-11 SILICONE STENTING FOR CHRONIC URETERAL OBSTRUCTION IMPROVES STENT EXCHANGE FREQUENCY Bebe Eke and Suwaee, Ga Noah Canvasser Bebe EkeBebe Eke More articles by this author and Suwaee, Ga Noah CanvasserSuwaee, Ga Noah Canvasser More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003280.11AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Chronic ureter stenting is recommended for patients with malignant ureteral obstruction, or with benign ureteral obstruction but cannot tolerate or do not want definitive surgical management. Stents are exchanged at time intervals often limited by stent encrustation; prior in vitro studies have demonstrated that silicone stents have less encrustation. Our objective was to compare patients undergoing chronic exchanges with polymer-based and silicone stents. METHODS: This IRB-approved retrospective study included all adult patients who underwent chronic ureter stent exchange from August 2017 through August 2022. Patients were stented with either a Boston Scientific PercuflexTM Plus or a Cook Black Silicone stent. Demographics, dates of exchange, stent type and size, and the presence of external and luminal encrustation were captured from operative reports. A subset of patients with >8F stents was analyzed given larger stents have lower rates of encrustation. Students t-test and chi-squared analysis were used to compare polymer-based vs silicone stents. RESULTS: In total, 52 patients underwent 165 stent exchanges: 72% were polymer-based (n=119), 28% were silicone (n=44), and 1% were metallic (n=2, excluded). Table 1 lists patient demographics and stent sizes. Mean exchange interval for silicone stents was significantly longer than for polymer-based stents (197±60 vs 139±87 days, p<0.0001). Despite this, there was no significant difference in external encrustation (9 vs 18%, p=0.18) or luminal encrustation (7% vs 4%, p=0.49). Sub-group comparison of stents >8F also showed longer exchange interval (191±40 vs 106±36 days, p<0.0001), similar external encrustation (10.3 vs 24%, p=0.13), and similar luminal encrustation (6.9 vs 5.6%, p=0.82). CONCLUSIONS: Utilizing silicone stents for chronic ureter stent exchanges significantly increases the exchange interval due to lower encrustation rates over similar time periods compared to a polymer-based stent. Further work with other polymer-based and silicone stents is warranted to evaluate the generalizability of these results. Source of Funding: COI: Consultant for Boston Scientific and Cook Medical, this study is unfunded © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e571 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Bebe Eke More articles by this author Suwaee, Ga Noah Canvasser More articles by this author Expand All Advertisement PDF downloadLoading ...

MP42-10 SELF-EXPANDING LARGE CALIBER URETERAL STENTS FOR TREATMENT OF IDIOPATHIC URETERAL STRICTURE

You have accessJournal of UrologyCME1 Apr 2023MP42-10 SELF-EXPANDING LARGE CALIBER URETERAL STENTS FOR TREATMENT OF IDIOPATHIC URETERAL STRICTURE Hyun Soo Lee, Sun Tae Ahn, Wonku Hwang, Seon Beom Jo, Jong Wook Kim, Mi Mi Oh, Hong Seok Park, and Du Geon Moon Hyun Soo LeeHyun Soo Lee More articles by this author , Sun Tae AhnSun Tae Ahn More articles by this author , Wonku HwangWonku Hwang More articles by this author , Seon Beom JoSeon Beom Jo More articles by this author , Jong Wook KimJong Wook Kim More articles by this author , Mi Mi OhMi Mi Oh More articles by this author , Hong Seok ParkHong Seok Park More articles by this author , and Du Geon MoonDu Geon Moon More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003280.10AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Treatment for the idiopathic ureteral stricture has not yet been established. Recently, efficacy of self-expanding large caliber stent (Allium, Allium LTD, Israel) for ureteral stricture related to surgery, radiation or malignancy was reported. This study aims to investigate the effect of Allium stent on idiopathic ureteral stricture. METHODS: From July 2018 and January 2022, 54 patients with 58 renal units were underwent ureteroscopic balloon dilation and placement of Allium stent. All the patients showed hydronephrosis before the stenotic lesion and pain. In all the patients, we used, 12 cm or 20cm length of self-expanding Allium ureteral stent and inserted retrogradely with intraoperative x-ray guidance after dilation of the stricture (Figure 1). The primary outcome was immediate improvement in pain and improvement in hydronephrosis through ultrasound examination at 1 month after the procedure. And the secondary outcome was stricture resolution rates following stent removal. RESULTS: Patients and ureteral stricture characteristics were summarized in Table 1. Of 54 patients, 20cm stent was inserted in 47 patients and 12cm stent was inserted in 7 patients. After median follow-up period of 16.5 months, 39.7 % (23/58) of stents were kept in situ. Median indwelling time was 10months (range 1-37) and stent migration was observed in 8 cases (13.8%). All the patients were immediately free of pain after the procedure, and through ultrasound examination, improvement of hydronephrosis was confirmed in 53 out of 58 renal units. Among the 42 renal units which stent removal was performed, 13 renal units (31.0%) recurred stricture. Logistic analysis showed that stricture length was a significant predicting factor for stent failure (HR 2.75, 95% CI 1.58, 4.79, p<0.01) CONCLUSIONS: Self-expanding allium ureteral stenting showed efficacy in relieving pain and improving hydronephrosis in idiopathic ureter stricture with minimal risk of complication. Overall success rate after stent removal was associated with preoperative stricture lengths. Source of Funding: None © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e570 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Hyun Soo Lee More articles by this author Sun Tae Ahn More articles by this author Wonku Hwang More articles by this author Seon Beom Jo More articles by this author Jong Wook Kim More articles by this author Mi Mi Oh More articles by this author Hong Seok Park More articles by this author Du Geon Moon More articles by this author Expand All Advertisement PDF downloadLoading ...

Self-expanding large caliber ureteral stents for treatment of idiopathic ureteral stricture

Self-expanding large caliber ureteral stents for treatment of idiopathic ureteral stricture

Iliac vein stent failure in community practice and results of corrective reinterventions

ObjectiveThe goal of endovenous stenting is to relieve venous obstruction and reduce peripheral venous hypertension by using large caliber venous stents in the presence of adequate venous inflow and outflow for the stented conduit. The aim of this report is to describe the technical reasons and outcomes for reinterventions in a subset of patients who had a history of iliac vein stenting and were now referred to us at a specialty venous clinic for further care. MethodsFrom January 2016 to December 2021, records of all patients who were referred to us with a history of iliac vein stenting performed at an outside facility and who had a reoperation performed at our center were retrospectively analyzed. ResultsA total of 149 limbs underwent a deep venous reintervention after a failure of a trial of conservative therapy. The mean age of the sample was 57 ± 16 years. The ratio of non-thrombotic iliac vein lesions to post-thrombotic lesions was 1:2.5. The majority of the patients (84%) were CEAP class C4 or higher. The most common reason for reintervention was stent occlusion (74%), followed by iatrogenic stenosis (53%) and in-stent restenosis/shelving (38%). There was a trend for improvement in all clinical parameters (venous clinical severity score, visual analog scale for pain, and edema grade) after the reintervention. Poor inflow was present in 70% of limbs with stent occlusion. The median diameters of stented common femoral vein, external iliac vein, and common iliac vein prior to reintervention were 12, 12, and 13 mm, respectively. The median diameters of stented common femoral vein, external iliac vein, and common iliac vein after reintervention were 14, 15, and 16 mm, respectively. Eighty-eight percent of limbs required at least one further reintervention after initial reoperation. ConclusionsVenous reoperations are generally infrequent and required in a small number of patients. Poor inflow appeared to be a common cause of stent occlusion. Iatrogenic stenosis is another common reason for venous reoperation and is difficult to fully rectify through current endovascular techniques and tools. Use of intravascular ultrasound planimetry routinely in every deep venous intervention and thorough knowledge of the principles of venous stenting outlined in this report may help forestall the need for reoperative deep venous surgery in some cases.

Rent Dissipation in Simple Tullock Contests

We investigate observed rent dissipation—the ratio of the total costs of rent seeking to the monetary value of the rent—in winner-take-all and share contests, where preferences are more general than usually assumed in the literature. With concave valuation of the rent, we find that contests can exhibit observed over-dissipation if the contested rent is below a threshold and yet observed under-dissipation with large rents: the nature of preferences implies contestants are relatively effortful in contesting small rents. Considering more general preferences in contests thus allows us to reconcile the Tullock paradox—where rent-seeking levels are relatively small despite the contested rent being sizeable—with observed over-dissipation of rents in experimental settings, where contested rents are arguably small.

Heating of Large Endovascular Stents and Stent Grafts in Magnetic Particle Imaging—Influence of Measurement Parameters and Isocenter Distance

PurposeMagnetic particle imaging (MPI) is a tomographic imaging modality with the potential for cardiovascular applications. In this context, the extent to which stents are heated should be estimated from safety perspective. Furthermore, the influence of the measurement parameters and stent distance to the isocenter of the MPI scanner on stent heating were evaluated.Materials and MethodsNine different endovascular stents and stent grafts were tested in polyvinyl-chloride tubes. The stents had diameters from 10 to 31 mm, lengths between 25 and 100 mm and were made from stainless steel, nitinol or cobalt-chromium. The temperature differences were recorded with fiber-optic thermometers. All measurements were performed in a preclinical commercial MPI scanner. The measurement parameters were varied (drive field strengths: 3, 6, 9, 12 mT and selection field gradients: 0, 1.25 and 2.5 T/m). Furthermore, measurements with different distances to the scanner’s isocenter were performed (100 to 0 mm).ResultsAll stents showed heating (maximum 53.1 K, minimum 4.6 K). The stent diameter directly correlated with the temperature increase. The drive field strength influenced the heating of the stents, whereas the selection field gradient had no detectable impact. The heating of the stents decreased with increasing distance from the scanner’s isocenter and thus correlated with the loss of the scanner’s magnetic field.ConclusionStents can cause potentially harmful heating in MPI. In addition to the stent diameter and design, the drive field strength and the distance to the MPI scanner’s isocenter must be kept in mind as influencing parameters.

Stent imaging on a clinical dual-source photon-counting detector CT system-impact of luminal attenuation and sharp kernels on lumen visibility.

To assess the impact of scan modes and reconstruction kernels using a novel dual-source photon-counting detector CT (PCD-CT) on lumen visibility and sharpness of different stent sizes. A phantom containing six balloon-expandable stents (2.5 to 9 mm diameter) in silicone tubing was scanned on a PCD-CT with standard (0.6 mm and 0.4 mm thicknesses) and ultra-high-resolution (0.2 mm thickness) modes. With the use of increasing contrast medium concentrations, densities of 0, 200, 400, and 600 HU were achieved. Standard-resolution scans were reconstructed using increasing sharpness kernels, using both polyenergetic quantitative soft tissue "conventional" ((Qr40c(0.6 mm), Qr40c(0.4 mm), Qr72c(0.2 mm)) and vascular (Bv) virtual monoenergetic reconstructions (Bv44m(0.4 mm), Bv60m(0.4 mm)) at 70 keV. In-stent lumen visibility, sharpness (max. ΔHU of the stent measured in profile plots), and in-stent noise (standard deviation of HU) were measured. In-stent lumen visibility was highest for Qr72c(0.2 mm) (86.5 ± 2.8% to 88.3 ± 2.6%) and in Bv60m(0.4 mm) reconstructions (77.3 ± 2.9 to 82.7 ± 2.5%). Lumen visibility was lowest in the smallest stent (2.5 mm) ranging from 54.1% in Qr40c(0.6 mm) to 74.1% in Qr72c(0.2 mm) and highest in the largest stent (9 mm) ranging from 93.8% in Qr40c(0.6 mm) to 99.1% in the Qr72c(0.2 mm) series. Lumen visibility decreased by 2.1% for every 200-HU increase in lumen attenuation. Max. ΔHU between stents and stent lumen was highest in Qr72c(0.2 mm) (ΔHU 892 ± 504 to 1526 ± 517) and Bv60m(0.4 mm) series (ΔHU 480 ± 357 to 1030 ± 344). Improvement of lumen visibility and sharpness in UHR and Bv60m(0.4 mm) series was strongest in smaller stent sizes. UHR acquisition mode and sharp reconstruction kernels on a novel PCD-CT system significantly improve in-stent lumen visibility and sharpness-especially for smaller stent sizes. • In-stent lumen visibility and sharpness of stents significantly improve using sharp reconstruction kernels (Bv60) and ultra-high-resolution mode in photon-counting detector computed tomography. • The observed improvement of stent-lumen visibility was highest in smaller stent sizes.

Rethinking the Lebanese economic miracle: The extreme concentration of income and wealth in Lebanon, 2005–2014

I combine household surveys, national accounts and unique personal income tax records to produce the first estimates of the national income distribution in an Arab country, Lebanon. I find that income is extremely concentrated over the 2005–2014 period: The top 1 and 10 percent of the adult population received almost 25 and 55 percent of national income on average, placing Lebanon among the countries with the highest levels of income inequality in the world. These results challenge a long lasting narrative according to which inequality levels are not that high in the Middle East. They also confirm results from a large literature that emphasizes how the Lebanese sectarian-based mode of governance has allowed the ruling elite to extract large rents for decades and at the expense of the majority of citizens.

In vitro performance of Lifetech IBS Angel™ (iron-based bioresorbable scaffold) stents during overdilation for use in pediatric patients.

The objective of this study was to assess the mechanical performance of the Lifetech IBS Angel stents during overdilation as is often required in pediatric applications; including time of first fracture, foreshortening, and the type of fracturing that occurs. In vitro testing was performed and repeated for each stent three times under physiologic conditions with continuous audiovisual imaging allowing for post-testing evaluations. Assessment of sheath fit was also completed. A total of 47 stents on monorail system were overdilated to complete fracture after passing through either a 4 or 5 French sheath. First strut fracture occurred in 4 and 6 mm stents when they reached greater than 50% overexpansion. Larger stents could achieve at least 30% increased diameter prior to first strut fracture. No fragmentation of any of the stents was seen throughout testing. The IBS Angel has thin struts allowing for a lower profile with increased maneuverability and use with smaller sheaths. Embolization potential of strut fragments was not seen. Increased diameter well beyond design parameters was seen in all with acceptable foreshortening.

Abstract 14105: Stent Ahoy: Ventricular Tachycardia Due to Stent Migration Into the Right Ventricle

Case: A 46-year-old female with PMHx of ESRD on dialysis and prothrombin gene mutation presented with acute onset of left breast swelling, redness and pain for nearly 24 hours. She was found to have SVC occlusion and underwent successful SVC recanalization and stent placement with an uncovered 14x40 mm nitinol stent. She presented 4 days later with complaints of chest pain and shortness of breath. Initial vitals were notable for tachypnea with oxygen saturations of nearly 70%, and a blood pressure of 114/71 mmHg. Physical exam demonstrated an obese female in distress. Shortly after arrival in the emergency department, she developed a non-sustained episode of ventricular tachycardia (NSVT). Amiodarone and lidocaine were started, however, she continued to have runs of NSVT. Initial CXR found no acute process but failed to demonstrate the previously placed SVC stent. ECG demonstrated normal sinus rhythm with frequent PVCs and runs of NSVT. A limited echo demonstrated a free edge of an endovascular stent within the right ventricle. TEE demonstrated the stent appeared to be tethered to the septal leaflet of the tricuspid valve with the leading edge free within the right ventricle. Endovascular retrieval was proposed but given the degree of entanglement within the tricuspid leaflets, large stent size, and recurrent NSVT, was deemed an unsuitable therapeutic strategy. Urgent open-heart surgery was performed for removal. The patient tolerated the procedure well and had no further recurrence of NSVT. Discussion: Stent migration is a rare but feared complication of venous stent deployment, with only 32 reported cases over the past 30 years. While NSVT is often attributed to the RVOT, the etiology being the result of migrated stents has been rarely reported. This is the first case to our knowledge of SVC stent migration leading to runs of NSVT. Conclusion: Clinicians must remain cognizant of the risk for venous stent migration and unusual clinical presentations resulting from migration.

Pulmonary vein stenosis – ballooning vs. stenting: a systematic review and meta-analysis

Abstract Background Pulmonary vein stenosis (PVS), which is often unrecognized, may arise from a variety of conditions resulting in major morbidity and mortality. In some patients, pharmacological therapy may help but more often in advance stages, mechanical treatment must be considered. Transcatheter approaches, both balloon angioplasty (BA) and stent implantation have been applied. While both may be effective, they continue to be limited by restenosis. Herein, we compare the outcomes following BA and stenting for PVS. Purpose PVS presents a challenge for both diagnosis and therapy, with BA and stenting being primarily limited by restenosis. Stenting is performed in most cases and is associated with improved patency rates. Historical comparisons of BA and stenting for PVS have yielded similar results. Our analysis incorporates more conventional studies (2010–2021) and provides a larger stent (N=361) versus BA (N=229) contemporary analysis of the current state of PV intervention practice. Methods From January 1, 2010 to August 2, 2021, studies, limited to English language and humans, were assessed in Ovid MEDLINE®, Ovid Embase, Ovid Cochrane Central Register of Controlled Trials, Ovid Cochrane Database of Systematic Reviews, and Scopus. Two independent reviewers screened articles including those in which balloon angioplasty or stenting was performed for pulmonary vein stenosis with reporting of restenosis outcomes and data was independently extracted. Systematic review was performed, and overall restenosis rates were reported across all included studies. Meta-analysis was then performed using RevMan 5.4 assessing rates of restenosis and restenosis requiring repeat intervention. Results Our systematic review yielded 34 studies reporting on BA and/or stenting for PVS. Of these, 7 studies (1–7), treating a total of 343 patients with 590 PV interventions (229 BA and 361 Stents) reported restenosis rates with mean follow-up ranging from 10 to 60 months. Stenting was associated with a lower risk of restenosis compared to balloon angioplasty [risk ratio 0.35, 95% CI (0.18, 0.64), p=0.0008] (Figure 1). Restenosis requiring repeat intervention was reported in 5 studies, including 303 patients with 502 PV interventions (160 BA and 342 Stents) with stenting similarly associated with a lower risk of restenosis requiring re-intervention [risk ratio 0.34, 95% CI (0.16, 0.72), p=0.005]. Conclusion Stenting for pulmonary vein stenosis is associated with reduced risk of restenosis and re-intervention as compared to balloon angioplasty. Funding Acknowledgement Type of funding sources: None.