Large Stent Research Articles

Large Bariatric-Specific Stents and Over-the-Scope Clips in the Management of Post-Bariatric Surgery Leaks.

Endoscopic stents are successful in the management of surgical leaks; however, stent migration remains a significant problem. In this study, we present our approach depending on a large bariatrics-specific stent (Mega stent) and over-the-scope clips in the management of post-bariatric surgery leaks. A retrospective analysis of all patients with post-bariatric surgery leaks treated at our institution using an approach reliant on Mega stents and over-the-scope clips was conducted. Potential factors associated with procedure success and occurrence of complications were also evaluated. A total of 81 stents were inserted in 62 patients with post-bariatric surgery leaks, 46 sleeve gastrectomies (73%) and 16 Roux-en-Y gastric bypass (27%). Over-the-scope clips were applied in 29 patients (46%). Leak closure was achieved in 51 patients (82%). Median number of procedures per patient was 3 (range 2-8). Complications included the following: stent migration (11/62, 18%), intolerance necessitating premature removal (7/62, 11%), esophageal stricture (8/62, 13%), bleeding (4/62, 6%), perforation (4/62, 6%). One stent-induced mortality was encountered (bleeding). The presence of open surgery (vs laparoscopic) was significantly associated with the occurrence of stent-induced complications (p 0.002). The approach combining Mega stents and over-the-scope clips is highly effective in the management of post-bariatric surgery leaks and is associated with a low rate of stent migration and a low number of procedures and stents per patient. Mega stents, however, should be used with great caution due to the significant morbidity associated with their use.

Predictors of major adverse cardiac events following elective stenting of large coronary arteries

ObjectiveDiameter of the affected coronary artery is an important predictor of restenosis and need for revascularization. In the present study, we investigated the frequency and potential risk factors for major adverse cardiac events following elective percutaneous coronary intervention (PCI) and stenting of large coronary arteries. MethodsWe reviewed the data of elective candidates of PCI on a large coronary artery who presented to our center. Demographic, clinical, angiographic and follow-up data of the eligible patients were retrieved from our databank. The study characteristics were then compared between the patients with and without MACE in order to find out the probable risk factors for MACE in patients with large stent diameter. ResultsData of 3043 patients who underwent single vessel elective PCI with a stent diameter of ≥3.5mm was reviewed. During a median follow up period of 14 months, 64 (2.1%) patients had MACE. TVR was the most common type of MACE that was observed in 29 patients, while 5 patients had cardiac death. Higher serum levels of creatinine, history of cerebrovascular accident (CVA), and use of a drug eluting stent (DES) were significantly associated with MACE. In the multivariate model, history of CVA (odds ratio=5.23, P=0.030) and use of DES (odds ratio=0.048, P=0.011) were the independent predictors of MACE in patients underwent large coronary artery stenting. ConclusionThis study showed that prior CVA and the use of BMS were the potential risk factors for MACE in patients who were stented on their large coronary arteries.

Endoscopic Management of Peri-Pancreatic Fluid Collections.

In the past decade, there has been a progressive paradigm shift in the management of peri-pancreatic fluid collections after acute pancreatitis. Refinements in the definitions of fluid collections from the updated Atlanta classification have enabled better communication amongst physicians in an effort to formulate optimal treatments. Endoscopic ultrasound (EUS)-guided drainage of pancreatic pseudocysts has emerged as the procedure of choice over surgical cystogastrostomy. The approach provides similar success rates with low complications and better quality of life compared with surgery. However, an endoscopic “step up” approach in the management of pancreatic walled-off necrosis has also been advocated. Both endoscopic and percutaneous drainage routes may be used depending on the anatomical location of the collections. New-generation large diameter EUS-specific stent systems have also recently been described. The device allows precise and effective drainage of the collections and permits endoscopic necrosectomy through the stents.

Atrium Advanta V12 Large Diameter Stent-Graft Applications for Infrarenal Abdominal Aortic Pseudoaneurysms (due to Behcet Disease): Safety and Efficacy

The aim of the study was to determine the safety and effectiveness of Atrium Advanta V12 large diameter stent-graft applications for infrarenal abdominal aortic pseudoaneurysms (due to Behcet disease [BD]). Data of Advanta V12™ (Atrium Europe B.V, Mijdrecht, the Netherlands) applied 12 female patients (mean age 30.5±6.3, range 26-44) with infrarenal abdominal aortic pseudoaneurysms were analyzed retrospectively. All Advanta V12 large diameter stent grafts were implemented from right or left sided 12F femoral sheaths. Stent grafts with 12-16mm in size and 29-61mm in length were utilized. Technical success rate, procedure-related mortality and morbidity, and primary patency rate at 4 years were evaluated. Technical success rate was 100%. Neither procedure-related mortality nor morbidity was determined. The mean aortic diameter was 14.0±0.8mm for pseudoaneurysmatic abdominal aortas. The mean follow-up period was 46.5±40.3months (range 18-75). During follow-ups, only one recurrent aneurysm has evolved at the stenting site due to patients' withdrawal of immunosuppressive treatment. The advent of a new aneurysm proximal or distal to the stent-graft region or at the femoral access localization was not observed. There were no stent occlusions. Primary patency rate at 4 years was 100%. Complete aneurysm exclusion was achieved 100% at 48months. The use of Advanta V12 large diameter stent grafts for infrarenal abdominal aortic pseudoaneurysms (due to BD), especially in female patients with small aortic diameter, is safe and efficient. Primary patency rate of the stent grafts at 4 years is excellent.

Independent predictors of in-stent restenosis after drug-eluting stent implantation for ostial right coronary artery lesions

ObjectivesWe evaluated the angiographic patterns and predictors of in-stent restenosis (ISR) for ostial lesions of the right coronary artery (RCA) to clarify the mechanism of insoluble restenosis. BackgroundAlthough ISR of the RCA still occurs, limited data is available regarding the associated angiographic findings. MethodsBetween January 2005 and September 2013, we recruited consecutive patients undergoing routine angiography 6–18months after implantation of a drug-eluting stent (DES). Multiple logistic regression analysis was used to determine the independent predictors of ISR, and the adjusted odds ratios (aOR) and 95% confidence intervals (95% CI) were calculated. ResultsRoutine angiography revealed that 45 of 131 patients (34.3%) had RCA-ISR, which were classifiable by occlusion type into ostial (24 cases), proximal (17 cases), diffuse (3 cases), and total (1 case). By multivariable analysis, early generation DES was the only independent predictor of overall ISR (aOR, 3.54; 95% CI, 1.59–7.87; p=0.002). In a subgroup analysis of each focal ISR pattern, early generation DES (aOR, 7.76; 95% CI, 2.15–28.0; p=0.002) was associated with increased risk of ostial ISR. On the contrary, larger stent (aOR, 0.21; 95% CI, 0.05–0.84; p=0.027) was associated with decreased risk of ostial ISR. Furthermore, a ratio of the stent to post-balloon size >1.10 (aOR, 3.93; 95% CI, 1.30–11.8; p=0.002) and good left ventricular contractility (ejection fraction >60%) (aOR, 8.27; 95% CI, 1.76–39.0; p=0.008) were associated with increased risk of proximal ISR when stent fracture was observed. ConclusionThe focal pattern of RCA-ISR was mostly observed after DES implantation, and the mechanisms of proximal and ostial ISR differed.

Imaging of pediatric great vessel stents: Computed tomography or magnetic resonance imaging?

BackgroundComplications might occur after great vessel stent implantation in children. Therefore follow-up using imaging is warranted.PurposeTo determine the optimal imaging modality for the assessment of stents used to treat great vessel obstructions in children.Material and methodsFive different large vessel stents were evaluated in an in-vitro setting. All stents were expanded to the maximal vendor recommended diameter (20mm; n = 4 or 10mm; n = 1), placed in an anthropomorphic chest phantom and imaged with a 256-slice CT-scanner. MRI images were acquired at 1.5T using a multi-slice T2-weighted turbo spin echo, an RF-spoiled three-dimensional T1-weighted Fast Field Echo and a balanced turbo field echo 3D sequence. Two blinded observers assessed stent lumen visibility (measured diameter/true diameter *100%) in the center and at the outlets of the stent. Reproducibility of diameter measurements was evaluated using the intraclass correlation coefficient for reliability and 95% limits of agreement for agreement analysis.ResultsMedian stent lumen visibility was 88 (IQR 86–90)% with CT for all stents at both the center and outlets. With MRI, the T2-weighted turbo spin echo sequence was preferred which resulted in 82 (78–84%) stent lumen visibility. Interobserver reliability and agreement was good for both CT (ICC 0.997, mean difference -0.51 [-1.07–0.05] mm) and MRI measurements (ICC 0.951, mean difference -0.05 [-2.52 –-2.41] mm).ConclusionGood in-stent lumen visibility was achievable in this in-vitro study with both CT and MRI in different great vessel stents. Overall reliability was good with clinical acceptable limits of agreement for both CT and MRI. However, common conditions such as in-stent stenosis and associated aneurysms were not tested in this in-vitro study, limiting the value of the in-vitro study.

Deep venous thrombosis associated with caval extension of iliac stents.

It is generally difficult to place an iliac vein stent precisely at the iliocaval junction with venographic control or even with intravascular ultrasound guidance. Furthermore, mechanical properties of the Wallstent (Boston Scientific, Marlborough, Mass) can predispose precisely placed stents to distal displacement or stent collapse. Our center has thus advocated extending Wallstents 3 to 5 cm into the inferior vena cava to prevent complications of missed proximal lesions or stent migration. This technique has gradually been accepted, and concerns of jailing of contralateral flow were not initially recognized. We analyzed deep venous thrombosis (DVT) incidence following iliocaval stenting with two alternative techniques: (1) Wallstents with 3- to 5-cm extension into the inferior vena cava; and (2) a modified Z-stent (Cook Medical, Bloomington, Ind) technique, in which overlapping Wallstents end at the iliac confluence and caval extension is performed with a Z-stent placed at the top of the stack. The function of the Z-stent is to provide improved radial force at the iliocaval confluence and to prevent jailing of contralateral flow with larger stent interstices. There were 755 limbs with consecutive Wallstent caval extensions (2006-2010) and 982 limbs with Z-stent extensions (2011-2015) analyzed for DVT incidence postoperatively. Demographics were similar for both groups. Mean age was 56 and 58 years in the Wallstent and Z-stent groups, respectively. There was a female predominance (Wallstent, 69%; Z-stent, 67%) and a higher incidence of left-sided disease (Wallstent, 66%; Z-stent, 56%) in both groups. There was a slightly higher incidence of post-thrombotic disease in the Z-stent subgroup (Wallstent, 53%; Z-stent, 68%). Cumulative freedom from contralateral DVT was 99% and 90% in the Z-stent and Wallstent groups, respectively (P< .001) during the 5 years following stent placement. However, all three patients with DVT contralateral to a Z-stent actually had high placement of the Wallstent across the confluence. Thus, no patients with proper Z-stent technique had a contralateral DVT. Cumulative freedom from ipsilateral DVT was 97% and 82% in the Z-stent and Wallstent groups, respectively (P< .001) during the 5 years following stent placement. The decrease in incidence of ipsilateral DVT appeared to be attributable to decreased missed distal lesions with increased operator experience and not attributable to the Z-stent itself. Contralateral DVT incidence was significantly lower with the Z-stent modification. In addition, the Z-stent modification provides greater radial strength at the iliac-caval confluence and simplifies simultaneous or sequential bilateral stenting. Use of proper technique and intravascular ultrasound is essential to limit the incidence of ipsilateral DVT.

Endoscopic bilateral stent-in-stent placement for malignant hilar obstruction using a large cell type stent

Bilateral stent-in-stent (SIS) self-expandable metal stent placement is technically challenging for palliation of unresectable malignant hilar obstruction. In the SIS technique, the uniform large cell type biliary stent facilitates contralateral stent deployment through the mesh of the first metallic stent. This study aimed to assess the technical success and clinical effectiveness of this technique with a uniform large cell type biliary stent. Thirty-one patients who underwent bilateral SIS placement using a large cell type stent were reviewed retrospectively. All patients showed malignant hilar obstruction (Bismuth types II, III, IV) with different etiologies. Sixteen (51.6%) patients were male. The mean age of the patients was 67.0+/-14.0 years. Most patients were diagnosed as having hilar cholangiocarcinoma (58.1%) and gallbladder cancer (29.0%). Technical success rate was 83.9%. Success was achieved more frequently in patients without masses obstructing the biliary confluence (MOC) than those with MOC (95.2% vs 60.0%, P=0.03). Functional success rate was 77.4%. Complications occurred in 29.0% of the patients. These tended to occur more frequently in patients with MOC (50.0% vs 19.0%, P=0.11). Median time to recurrent biliary obstruction was 188 days and median survival was 175 days. The large cell type stent can be used efficiently for bilateral SIS placement in malignant hilar obstruction. However, the risk of technical failure increases in patients with MOC, and caution is needed to prevent complications for these patients.

Abstract 13847: Impact of the Unzipping Technique on Pulmonary Artery Structure and Growth

Introduction: With the unzipping technique, small diameter stents are implanted to relieve pulmonary artery (PA) stenosis, subsequently dilated, fractured and re-stented with large stents dilatable to adult PA diameters. The unzipping technique is utilized in clinical practice with undefined long term results. This study assessed the impact of unzipping on PA structure and growth. Methods: Twelve piglets with left PA (LPA) stenosis underwent the unzipping sequence at 6, 10 and 18 weeks of age and were compared to normal controls and controls with untreated LPA stenosis. 2D and 3D rotational angiography pre/post interventions and PA histology was performed on all animals. Results: Eleven of twelve animals completed the three catheterizations. One stent (4 mm implant diameter) could not be crossed at the second procedure. Following the interventions, the diameter of the unzipped LPA was similar to the proximal LPA of normal controls (14 mm ± 1.2 vs 14.7 mm ± 1, p = 0.19). The diameter of the distal LPA was larger in normal controls, compared to interventions and controls with untreated LPA stenosis (14.6 mm ± 0.9 vs 11.6 mm ± 1.9, vs 10 mm ± 1.2, p &lt; .01). Diameters of six 1 st order LPA branches were similar between normal controls and interventions, and larger than the branch diameters in the stenosis controls. Right PA (RPA) dimensions were larger in controls with untreated stenosis, compared to normal controls and interventions (17.8 mm ± 1.2 vs 16.2 mm ± .9 vs 16 ± 1.7 mm p&lt;0.05). RPA 1 st order branching diameters were similar for normal controls and interventions. RPA 1 st order branch diameters in stenosis controls were larger for 3 of 6 branches compared to normal controls and 1 of 6 compared to interventions. Histologically, the distal LPA displayed uniform fibrointimal proliferation and smooth muscle hypertrophy in pigs with both interventions and untreated stenosis. Focal RPA fibrointimal proliferation was noted in stenosis and intervention animals. Conclusion: PA growth distal to the unzipped segment is partially compromised, yet 1 st order branch diameters are normal and significantly larger, compared to untreated stenosis. Histological vascular abnormalities are noted bilaterally in stenosis animals which do not normalize following the unzipping technique.

TCT-313 Incidence and Predictors of Very Late Major Adverse Cardiac Events After Metallic Stents: A Patient-Level Pooled Analysis from Seventeen Randomized Trials

Limited data are available regarding very late (>1 year) major adverse cardiac events (MACE) after metallic stent implantation. We therefore examined rates and predictors of very late MACE from a large pooled drug-eluting stent (DES) trial database. Patient-level data from 17 randomized DES trials

Exogenous Resource Shocks and Economic Freedom

There is an extensive literature on the presence of valuable natural resources creating a competition for control of central states and resource rents. This mechanism has been argued to be an important underlying factor preventing certain countries from acquiring good institutions and achieving long run economic growth. In this paper, we use a recent data set on the discovery of large, exogenous oil field discoveries as a means of testing whether the presence of large resource rents maligns the freedom of a country’s economic institutions. We find there to be some evidence of contemporaneous effects of these discoveries on the size of government spending, especially transfer payments and subsidies, but this does not show up in our overall measure of economic freedom. These effects also dissipate with time to statistical and economic insignificance, suggesting the discoveries have short run effects on policy but do not impact the underlying institutions at all. At least for this set of exogenous resource discoveries, there is no resource curse for economic freedom.

The Use and Outcomes of Small, Medium and Large Premounted Stents in Pediatric and Congenital Heart Disease.

We sought to describe the use and outcomes of small, medium and large premounted stents in patients with congenital heart disease, including incidence of and risk factors for re-intervention and development of in-stent stenosis. Premounted stents offer several advantages over traditional manually crimped bare-metal stents, especially in small patients. There are no data describing the medium-term effectiveness and outcomes of premounted stents in congenital heart disease. We performed a single-center retrospective review of all small, medium and large premounted stents implanted over an 8-year period. Premounted stents were implanted in 71 vessels within 59 patients with a 97% success rate. Regardless of implantation site, premounted stent implantation resulted in significant improvements in vessel size and pressure gradient (p<0.0001). Over a median follow-up duration of 3.1years [interquartile range (IQR) 1.3-5.2], 25 patients (43%) required re-intervention (18 catheter based, 3 surgical and 4 hybrid) at a median time of 1.4years (IQR 0.9-3.0) from implant. Factors associated with re-intervention included age ≤1.9years [hazard ratio (HR) 2.4, p=0.03], weight ≤11.5kg (HR 2.5, p=0.03) and bare-metal premounted stents compared to covered premounted stents (HR 4.2, p=0.001). In-stent stenosis was diagnosed in 42% of premounted stents which underwent follow-up angiography. No identified characteristics were associated with in-stent stenosis, including "oversizing" the premounted stent. Small, medium and large premounted stents are effective in treating vascular stenosis in congenital heart disease. Frequent follow-up is required, especially in smaller patients with expected somatic growth, and to evaluate forin-stent stenosiswhich occurs in nearly half of premounted stents.

Prevalence and Clinical Impact of Tissue Protrusion After Stent Implantation

The aim of this study was to evaluate the prevalence and long-term clinical impact of tissue protrusion (TP) after stent implantation. Stent implantation may be associated with tissue (plaque or thrombus) protrusion, especially in unstable lesions, but its clinical impact is unknown. ADAPT-DES (Assessment of Dual Antiplatelet Therapy With Drug-Eluting Stents) was a prospective multicenter study of 8,663 patients undergoing percutaneous coronary intervention (PCI) using drug-eluting stents. In a pre-specified intravascular ultrasound (IVUS) substudy, 2,072 patients with 2,446 culprit lesions underwent post-PCI IVUS (among whomsome also underwent pre-PCI IVUS) and were classified according to the presence or absence of post-stent TP. After PCI, 34.3% of lesions displayed TP on IVUS. Median maximum TP was 0.7 mm(2) (interquartile range: 0.5 to 1.2 mm(2)) in area and 3.0 mm (interquartile range: 1.4 to 6.7 mm) in length. Patients with TP more often presented with ST-segment elevation myocardial infarction or non-ST-segment elevation myocardial infarction but less often with unstable angina or stable ischemic heart disease. In 893 culprit lesions that were also examined pre-PCI, TP was associated with larger reference luminal area, greater plaque burden, and more plaque ruptures, attenuated plaque, and virtual histology thin-cap fibroatheromas. Because a larger stent or post-dilation balloon was used, post-PCI luminal area was significantly larger in lesions with versus without TP. At 2-year follow-up, there was less clinically driven target lesion revascularization in lesions with TP and no significant difference in major adverse cardiac events (defined as cardiac death, myocardial infarction, or stent thrombosis) in patients with versus without TP. IVUS-detected TP after drug-eluting stent implantation was not associated with worse long-termclinical outcomes, in part because of greater stent expansion in lesions with TP.

Use of the AndraStent XL and XXL for the treatment of coarctation of the aorta in children and adults: immediate and midterm results.

The aim of this study is to present our experience with a new type of extra-large stent, namely the AndraStent XL/XXL. AndraStents were implanted in 46 patients, 38 with native coarctation of the aorta (CoA) and eight with recurrent coarctation of the aorta following previous surgery (ReCoA). All patients had arterial hypertension in the upper limbs, absent or weak femoral pulses, and continuous flow in the abdominal aorta on Doppler examination. The median age of patients was 25 years (range from nine to 65). The stents (cobalt-chromium with semi-open cell design) were manually mounted on balloon catheters and delivered through 10 to 14 Fr Mullins sheaths using a conventional femoral approach. All procedures were successful (no stent migration, proper expansion, no aorta dissection/rupture, major bleeding or major vessel injury). The systolic gradient across the aorta decreased from 40.6 mmHg before the procedure to 11.6 mmHg after the procedure (p<0.001). The mean fluoroscopy time was 5.7 minutes. Imaging examinations were scheduled and performed between six and 12 months after the initial procedure in 40 patients (angiography or angio CT or both). Procedural outcome remained favourable during a mean 2.4 years of follow-up. Neither stent fracture nor dislocation was observed in any patient at follow-up. In two patients, small aneurysm formation was observed six and eight months after the procedure -they were treated successfully with subsequent covered stent implantation. Re-dilatation of the implanted stent was performed between four and 26 months in 14 patients. Implantation of new large cobalt-chromium stents is a good therapeutic option for the treatment of native and recurrent CoA.

PTU-002 EUS-Guided Insertion of Fully Covered Self-Expandable Metal Stents for Drainage of Pancreatic Walled-Off Necrosis Does Not Require Fluoroscopy

Introduction Transgastric placement of specially designed fully covered self-expandable metal stent (FCSMS) has improved the management and the outcome of walled-off necrosis (WON) after severe pancreatitis. Reduction of radiation exposure is of increasing importance. Therefore, we investigated whether transgastric insertion of FCMS for drainage of WON is possible only by EUS-guidance. Methods Patients with symptomatic pancreatic walled-off necrosis referred for endoscopic drainage were included. EUS-guided stent insertion was performed under concious sedation or endotracheal intubation. The pancreatic collection was accessed from the stomach using a linear echoendoscope with a 19 G access needle, a cystotome or directly using the hot Axios® device. After insertion of a guidewire and enlargement of the transgastric access by diathermy a fully covered self-expandable metal stent was inserted under EUS guidance without fluoroscopy. As clinically indicated, endoscopic necrosectomy was performed through the large diameter metal stent. When the collection had shrunk to less than 4 cm, symptoms and inflammatory parametrs had improved, the stent was endoscopically removed. Results 18 patients (median age: 55 years; range 48–63 years) with symptomatic WON (median diameter: 14 cm; range 8–18 cm) were referred for EUS-guided drainage. In 2 patients large traversing arteries within the cavity were detected by colour Doppler imaging during EUS, therefore the insertion of FCSMS was not attempted to avoid possible erosion of the vessels by the stent edges with reducing collection size. In all other patients (88.9%) the completely EUS-guided transgastric stent insertion without fluoroscopy was technically successful (6 AXIOS® and 10 Nagi® stents were inserted). The stent insertion into the cavity and the opening of the distal flange could be clearly visualised by EUS in all cases. After correct positioning of the FCSMS by EUS the proximal stent flange was deployed under endoscopic guidance. Two patients were readmitted with fever when the stent was blocked with debris. Seven patients required endoscopic necrosectomy through the FCSMS. One patient developed self-limiting bleeding. WON resolved in all patients within 8 weeks. Conclusion The good sonographic visibility of the FCSMS throughout the procedure allows safe and easy insertion of transgastric drainage under EUS-guidance without fluoroscopy. Reference 1 Seifert H, Wehrmann T, Schmitt T, Zeuzem S, Caspary WF. Retroperito-neal endoscopic debridement for infected peripancreatic necrosis. Lancet 2000; 356:653–5. Disclosure of Interest None Declared

Coronary bifurcation lesions treated with simple or complex stenting: 5-year survival from patient-level pooled analysis of the Nordic Bifurcation Study and the British Bifurcation Coronary Study.

Randomized trials of coronary bifurcation stenting have shown better outcomes from a simple (provisional) strategy rather than a complex (planned two-stent) strategy in terms of short-term efficacy and safety. Here, we report the 5-year all-cause mortality based on pooled patient-level data from two large bifurcation coronary stenting trials with similar methodology: the Nordic Bifurcation Study (NORDIC I) and the British Bifurcation Coronary Study: old, new, and evolving strategies (BBC ONE). Both multicentre randomized trials compared simple (provisional T-stenting) vs. complex (culotte, crush, and T-stenting) techniques, using drug-eluting stents. We analysed all-cause death at 5 years. Data were collected from phone follow-up, hospital records, and national mortality tracking. Follow-up was complete for 890 out of 913 patients (97%). Both Simple and Complex groups were similar in terms of patient and lesion characteristics. Five-year mortality was lower among patients who underwent a simple strategy rather than a complex strategy [17 patients (3.8%) vs. 31 patients (7.0%); P = 0.04]. For coronary bifurcation lesions, a provisional single-stent approach appears to be associated with lower long-term mortality than a systematic dual stenting technique.

Sa2011 New Method to Insert Large Caliber Plastic and Self-Expanding Metal Stents During Balloon Overtube Enteroscopy (BAE) Assisted ERCP

Sa2011 New Method to Insert Large Caliber Plastic and Self-Expanding Metal Stents During Balloon Overtube Enteroscopy (BAE) Assisted ERCP

Application of combined-type Y-shaped covered metallic stents for the treatment of gastrotracheal fistulas and gastrobronchial fistulas

ObjectiveTo determine the safety and feasibility of combined-type integrated Y-shaped self-expanding covered metallic stents to treat gastrotracheal fistulas (GTFs) and gastrobronchial fistulas (GBFs). MethodsWe retrospectively reviewed the data of 10 patients with postoperative GTFs or GBFs. Depending on the size and location of the fistula and the airway diameter, we custom-designed 2 or 3 stents for each patient. The combined-type stents consisted of a large and a small Y-shaped stent. Under fluoroscopic guidance, the small stent was inserted into the distal part of the involved airway. Then, the large stent was placed at the trachea and carina. The large stent partly overlapped the main body of the small stent. ResultsAll stents were successfully inserted at the first attempt. Esophageal and airway radiography showed no contrast agent leakage, indicating that the fistula was fully sealed. After the procedure, the patients could resume eating without coughing, and their quality of life improved. Each patient was fully followed up. Six patients died at 3.2 to 8 months of tumors (4 patients), hemoptysis (1 patient), or pulmonary infection (1 patient). In 1 patient, the carinal fistula enlarged 4 months after stenting, and another small Y-shaped stent was inserted to seal the fistula. This patient and the remaining 3 patients are still alive. ConclusionsDeployment of the combined-type Y-shaped integrated self-expanding covered metallic stent proved to be an effective, safe, and minimally invasive procedure for complex GTFs and GBFs. Our patients tolerated the stents well and had good palliation of their symptoms.

Cream‐Skimming in Financial Markets

ABSTRACTWe propose a model in which investors may choose to acquire costly information that identifies good assets and purchase these assets in opaque (OTC) markets. Uninformed investors access an asset pool that has been cream‐skimmed by informed investors. When the quality composition of assets for sale is fixed, there is too much information acquisition and the financial industry extracts excessive rents. In the presence of moral hazard in origination, the social value of information varies inversely with information acquisition. Low quality origination is associated with large rents in the financial sector. Equilibrium acquisition of information is generically inefficient.

Intraoperative Hybrid Stenting of Recurrent Coarctation and Arch Hypoplasia with Large Stents in Patients with Univentricular Hearts

Objective: Obstruction of the reconstructed aortic arch, tubular hypoplasia and recurrent coarctation (RC) is an important risk factor after the Norwood procedure or similar surgery. Balloon angioplasty (BA) may be effective but pressure gradient relief is often incomplete, with a high incidence of restenosis usually within the first year. Percutaneous interventions may have an increased risk due to limited vascular access or a very tortuous catheter course. Combining operative and interventional approaches (hybrid procedures) with direct puncture of the heart or the great vessels may facilitate implantation of even large devices. For the past two years we have adopted the concept of intraoperative hybrid stenting of RC and arch hypoplasia with large stents in patients with univentricular hearts as standard care procedure.