Stent Fracture Research Articles

Ureteric stents: Overview of current clinical applications and economic implications.

Ureteric stents are one of the most crucial tools used for various clinical conditions in the urological field. Placement of a ureteric stent, for short- or long-term use, remains one of the commonest urological interventional procedures. In the past few decades, ureteral stents have undergone notable technological advancements. However, an ideal stent without significant side-effects is yet to be engineered. Indwelling ureteric stents are often accompanied by physical distress to the patient and clinical complications, such as bacterial adhesion, encrustation, malpositioning, stent fracture and forgotten stent syndrome, that influence patients' health-related quality of life. In the market, different stent types are available, designed to reduce infections, and improve patient symptoms and tolerance. In this review, we have emphasized the recent developments that have taken place in stent design, size, materials and coating. This overview looks at current practices and problems related to stents, along with clinical and economic considerations. Few trial studies have been enumerated in the context of utilization of a ureteral stent symptom questionnaire and various stent models to compare their effects in patients.

Lower Extremity Venous Stent Placement: A Large Retrospective Single-Center Analysis.

To study short-term and long-term outcomes of lower extremity venous stents placed at a single center and to characterize changes in vein diameter achieved by stent placement. A database of all patients who received lower extremity venous stents between 1996 and 2018 revealed 1,094 stents were placed in 406 patients (172 men, 234 women; median age, 49 y) in 513 limbs, including patients with iliocaval stents (9.4% acute thrombosis, 65.3% chronic thrombosis, 25.3% nonthrombotic lesions). Primary, primary assisted, and secondary patency rates were assessed for lower extremity venous stents at 1, 3, and 5 years using Kaplan-Meier analyses and summary statistics. Subset analyses and Cox regression were performed to identify risk factors for patency loss. Vein diameters and Villalta scores before and up to 12 months after stent placement were compared. Complication and mortality rates were calculated. Primary, primary assisted, and secondary patency rates at 5 years were 57.3%, 77.2%, and 80.9% by Kaplan-Meier methods and 78.6%, 90.3%, and 92.8% by summary statistics. Median follow-up was 199 days (interquartile range, 35.2-712.0 d). Patency rates for the subset of patients (n= 46) with ≥ 5 years of follow-up (mean ± SD 9.1 y ± 3.4) were nearly identical to cohort patency rates at 5 years. Patients with inferior vena cava stent placement (hazard ratio 2.11, P < .0001) or acute thrombosis (hazard ratio 3.65, P < .0001) during the index procedure had significantly increased risk of losing primary patency status. Vein diameters were significantly greater after stent placement. There were no instances of stent fracture, migration, or structural deformities. In patients with chronic deep vein thrombosis, Villalta scores significantly decreased after stent placement (from 15.7 to 7.4, P < .0001). Perioperative mortality was < 1%, and major perioperative complication rate was 3.7%. Cavo-ilio-femoral stent placement for venous occlusive disease achieves improvement of vein disease severity scores, increase in treated vein diameters, and satisfactory long-term patency rates.

PTA and Stenting of Femoropopliteal Trunk With Cordis Smartflex Stent System: A Single-Center Experience.

The aim of this study is to describe our experience in the treatment of femoropopliteal occlusive disease with percutaneous transluminal angioplasty (PTA) followed by stenting with S.M.A.R.T. Flex vascular stent system. From June 2014 to October 2018, 80 patients were treated at our Institution for intermittent claudication, critical, or acute limb ischemia due to total occlusion or long diffused lesions of the femoropopliteal segment. Main study end points are primary patency, target lesion revascularization, and stent fractures; secondary end points are major amputation rate, procedure-related bleeding, incidence of intrastent restenosis, and primary assisted patency after reintervention. Mean follow-up time was 21 months (range 2-48 months). Primary patency rate was 80% (64 patients of 80), with mean covered lesion length of 8.2 cm. The deployment of a single stent was obtained for 57 (89%) patients, with a mean stent length of 9.86 cm. Of 80 patients, 2 (2.5%) had early stent occlusion within first 48 hours after the procedure, while 4 (5%) of 80 patients experienced stent occlusion within first 6 months. Of 80 patients, 6 (7.5%) had an intrastent restenosis detected at duplex ultrasound with a primary-assisted patency after simple re-PTA procedures of 83.3% at 12 months. In the literature, primary patency after PTA and stenting of the femoropopliteal trunk seems to be related to several variables, such as number of stents used, specific stent length, diameters, type and length of lesions, type of pathology (if acute or chronic), and number of preoperatory patent below-the-knee vessels. In this study, we try to analyze each single factor in order to understand their role in predisposing specific stent restenosis. S.M.A.R.T. Flex vascular stent system has shown good results in terms of primary patency in the treatment of calcified lesions both at SFA and at popliteal level. However, in our experience, stent patency seems to be significantly poorer in patients presenting with acute limb ischemia associated with chronic atherosclerotic disease as well as for lesions located in the mid-distal part of the popliteal artery and both when number of stents increases or number of runoff vessel decreases.

A manufacturing and annealing protocol to develop a cold-sprayed Fe-316L stainless steel biodegradable stenting material

Biodegradable stents show promise to revolutionize coronary artery disease treatment. Its successful implementation in the global market remains limited due to the constraints of current generation biodegradable materials. Cold gas dynamic spraying (CGDS) has been proposed as a manufacturing approach to fabricate a metallic biodegradable amalgamate for stent application. Iron and 316L stainless steel powders are combined in a 4:1 ratio to create a novel biomaterial through cold spray. Cold spray processing however, produces a coating in a work hardened state, with limited ductility, which is a critical mechanical property in stent design. To this end, the influence of annealing temperature on the mechanical and corrosion performances of the proposed Fe-316L amalgamate is investigated. It was found that annealing at 1300 °C yielded a complex material microstructure, with an ultimate tensile strength of approximately 280 MPa and ductility of 23%. The static corrosion rate determined at this annealing temperature was equal to 0.22 mg cm−2 day−1, with multiple corrosion species identified within the degradation layers. Precipitates were observed throughout the microstructure, which appeared to accelerate the overall corrosion behaviour. It was shown that cold-sprayed Fe-316L has significant potential to be implemented in a clinical setting. Statement of SignificanceBiodegradable stents have potential to significantly improve treatment of coronary artery disease by decreasing or potentially eliminating late-term complications, including stent fracture and in-stent restenosis. Current generation polymer biodegradable stents have led to poorer patient outcomes in comparison to drug-eluting stents, however, and it is evident that metallic biomaterials are required, which have increased strength. To this end, a novel iron and stainless steel 316L biomaterial is proposed, fabricated through cold-gas dynamic spraying. This study analyses the effect of annealing on the Fe-316L biomaterial through corrosion, mechanical, and microstructural investigations. The quantitative data presented in this work suggests that Fe-316L, in its annealed condition, has the mechanical and corrosion properties necessary for biodegradable stent application.

Real-World Results of Supera Stent Implantation for Popliteal Artery Atherosclerotic Lesions: 3-Year Outcome

Reports our experience for the first 50 cases of use of Supera stent for popliteal atherosclerotic lesions treatment. This prospective single-arm trial enrolled the first 50 limbs (46 patients) treated in our center with a Supera stent for symptomatic atherosclerotic disease of the popliteal artery. Also, a follow-up of 36months is reported. The mean preoperative ankle-brachial index increased from 0.38±0.37 before intervention to 0.63±0.46 postoperatively at 12 months (P=0.014), 0.66±0.39 at 24 months (P=0.023), and 0.74±0.46 at 36 months (P=0.029). Primary patency at 12, 24, and 36months were 89.6%, 72.3%, and 70.2%, and primary assisted patency was 93.8%, 87.2%, and 85.1%, respectively, by Kaplan-Meier estimates. After 3 years of follow-up, age <75years (P=0.034) and Trans-Atlantic Inter-Society Consensus (TASC)-II D lesions (P=0.041) constituted risk factors for stent occlusion. During the follow-up of the patients, none of them developed stent fracture as evidenced on plain radiographs during follow-up. Implantation defects did not constitute a risk factor for stent restenosis. Based on the results of this study, Supera stent has shown an excellent 3-year patency in this difficult-to-treat anatomic segment. In our experience, younger patients and complex lesions (TASC-II type D) were positive significant predictors for restenosis. In our cohort, post deployment stent conformation did not influence patency. Nevertheless, further investigations, including randomized studies comparing the Supera stent with other stent platforms, drug eluting angioplasty, or atherectomy devices, are mandatory.

The incidence and risk factors of stent fracture in patients treated for proximal common carotid artery stenosis

ObjectiveOur aim was to identify the incidence of and predictors for common carotid artery (CCA) stent fractures (SFs) and to examine the effect of SFs on the development of in-stent restenosis (ISR). MethodsSeventy patients (37 women; median age, 60.9 years) who were stented for significant (≥60%) proximal CCA stenosis from 2006 to 2016 and revisited us to determine SF using fluoroscopy in 2018 were evaluated. Seventy stents were deployed; among them 87.1% were balloon-expandable and 12.9% were self-expandable. SFs were classified as type I (fracture of one strut), type II (fracture of multiple struts without stent deformity), type III (fracture of multiple struts with stent deformity), type IV (complete fracture of the stent without a gap), and type V (complete fracture of the stent with a gap). Duplex ultrasound examination was used for monitoring stent patency. Mann-Whitney U and Fisher's exact tests, Kaplan-Meier and logistic regression analyses, and a log-rank test and a gamma correlation analysis were applied as statistical methods. ResultsThe patients were followed for 75.5 months (range, 47-109 months). Significant (≥70%) ISR was observed in eight patients (11.4%). Reintervention was performed in four cases (5.7%). Twenty-seven SFs (38.6%; type I, 8; type II, 10; type III, 4; type IV, 2; and type V, 3) were found. Calcification was shown to be a significant predictor for SF (odds ratio, 13.2; 95% confidence interval, 3.9-45.1; P < .001). There was no significant difference between the fractured and the nonfractured group regarding the number of patients with ISR and reintervention (P = .701 and P = .636, respectively). Neither did the primary patency rates differ significantly (P = .372) in patients with and without SF. ConclusionsFractures frequently occur in a wide variety of stent devices deployed in the proximal CCA, but SFs seem to have no effect on ISR and reintervention.

Performance of BeGraft and BeGraft+ Stent-Grafts as Bridging Devices for Fenestrated Endovascular Aneurysm Repair: An In Vitro Study

Purpose: To investigate 2 generations of balloon-expandable covered stents as potential bridging devices using an in vitro model of stent-graft fenestrations. Materials and Methods: Twenty BeGraft and 20 BeGraft+ cobalt-chromium stents covered in expanded polytetrafluoroethylene (ePTFE) in 6- and 8-mm diameters were tested in sheets mimicking stent-graft fenestrations. Microscopy and radiography were employed to evaluate stent morphology after flaring. In vitro bench tests measured maximum pullout (perpendicular displacement) and the shear stress (axial displacement) forces needed to dislocate the stents. Results: No alteration of ePTFE coverage was detected in the flared stents. Digital radiography and computed tomography showed marked alteration of the stent geometry, which was more pronounced in the BeGraft group. No fractures were detected. Median (minimum–maximum) pullout forces for the 6-mm stent-grafts were 17.1 N (15.8–19.6) for the BeGraft device and 30.4 N (20.2–31.9) for the BeGraft+ device (p=0.006). Median (minimum–maximum) pullout forces for the 8-mm stent-grafts were 11.3 N (11–12.1) for the BeGraft device and 21.8 N (18.2–25.5) for the BeGraft+ device (p<0.001). The shear stress test showed median forces of 10.5 vs 15.28 N at 150% of the stent diameter for the 6-mm BeGraft and BeGraft+ stent-grafts, respectively, and 15.23 vs 20.72 N at 150% stent diameter for the 8-mm models (p=0.016 and 0.017, respectively). Conclusion: Flaring changed the stent geometry but did not provoke stent fractures. The BeGraft+ is superior to the BeGraft in terms of pullout and shear stress forces, demonstrating greater resilience.

Mid-term outcomes after percutaneous pulmonary valve implantation in complex right ventricular outflow tracts using the “folded” Melody® valve technique

BackgroundPercutaneous pulmonary valve implantation (PPVI) using Melody® valve has been validated as a valuable therapeutic option for the management of right ventricular outflow tract (RVOT) dysfunction but remains challenging [1–3]. The “Folded” modification of the Melody® valve has been reported as a safe and feasible technique in complex RVOT [4]. We sought to evaluate mid-term outcomes in a multicentre cohort who underwent PPVI using the “folded” Melody® valve technique. MethodsPatients who underwent PPVI using a Foled Melody® between April 2012 and November 2018 in 6 European tertiary Centers were retrospectively included. Results“Folded” Melody® valve technique was successfully performed in 28 patients (mean age=17.7±10 years old). Indications were: short RVOT and early bifurcation of pulmonary arteries in 12 (42.8%) (Fig. 1), bioprosthetic valves in 10 (35.7%), coronary arteries proximity in 4 (14.3%) and prevention of retrosternal compression in 2 (7.2%). No complication occurred during procedures. All patients had excellent hemodynamic results. Mean transvalvular peak velocity decreased from 3.8±0.86m/s before PPVI to 2.4±0.55m/s in the immediate post-PPVI period. Only 5 patients had trivial pulmonary regurgitation (PR) at discharge. After a median follow-up (FU) of 27±17.9 months, all patients were alive, and all, but 3 patients, were free from reintervention: 1 patient (3.5%) developed Melody® valve infective endocarditis 3 months after PPVI and underwent RVOT surgical replacement; Two underwent pulmonary artery stenting 2 and 4 years after of PPVI, but the lesions were not related to the Folded valve. At last FU mean transvalvular peak velocity was 2.6±0.66m/s and only 5 (17.8%) patients had mild or less PR. No stent fractures were observed. ConclusionThe “folded valve technique” is a safe and feasible modification of the Melody® valve which provides favourable mid-term results without increased rate of valve related complications.

Restenosis of Drug-Eluting Stents: A New Classification System Based on Disease Mechanism to Guide Treatment and State-of-the-Art Review.

Despite on-going evolution and iteration of drug-eluting stent (DES) technology, the prevalence of in-stent restenosis (ISR) remains relatively unchanged, encompassing ≈10% of percutaneous coronary interventions. The mechanism of ISR is multifactorial, including biological, mechanical, patient, and operator-related factors. The main mechanical contributors are stent underexpansion or fracture, while biological factors include local inflammation leading to aggressive neointimal proliferation and late neoatherosclerosis. Intracoronary imaging is critical to identify the mechanism of ISR and tailor therapy accordingly. The presentation of DES-ISR is not benign and is challenging for optimal treatment. Among the proposed treatment modalities are scoring and high-pressure balloons, percutaneous coronary intervention with additional DES, atheroablative therapies by laser or mechanical atherectomy, drug-coated balloons, vascular brachytherapy, and surgical revascularization. We propose a new classification for ISR that differentiates among mechanical, biological, and mixed etiologies. Stratifying ISR by mechanism guides individualized treatment of DES-ISR to improve clinical outcomes. An algorithmic approach, guided by intracoronary imaging, for the treatment of DES-ISR, is recommended based on the specific cause of restenosis.

Correlations among tracheal dimensions, tracheal stent dimensions, and major complications after endoluminal stenting of tracheal collapse syndrome in dogs.

BackgroundEndoluminal tracheal stenting can relieve signs associated with tracheal collapse syndrome (TCS) in dogs, but major complications can result.ObjectiveTo identify associations among tracheal dimensions, stent dimensions, and subsequent complications requiring additional stent placement after endoluminal stenting for TCS.AnimalsFifty‐two dogs from the hospital population.MethodsMedical records of dogs that received an endoluminal self‐expanding tracheal stent for TCS by the interventional radiology service between 2009 and 2014 were reviewed for relevant data. Signalment and clinical details, including tracheal collapse type, tracheal measurements, nominal stent dimensions, follow‐up evaluation times, and stent complications, were recorded.ResultsFifty‐two dogs that received an endoluminal stent for TCS met the inclusion criteria. Major complications included stent fracture (13/52; 25%), obstructive tissue ingrowth (10/52; 19%), and progressive tracheal collapse (6/52; 12%). Natural tracheal taper (P = .04) and more stent diameter oversizing (P = .04) in the intrathoracic (IT) trachea were associated with caudodorsal stent fracture. Only stents with a 14‐mm nominal diameter fractured. Progressive tracheal collapse was associated with smaller maximum tracheal diameters (P = .02). The majority of dogs with obstructive tissue ingrowth (7/10; 70%; P = .30) and all dogs with thoracic inlet fractures (3/3; 100%) had tracheal malformations.Conclusions and Clinical ImportanceA higher taper in tracheal diameter may lead to increased risk of fracture in the IT location. Dogs with tracheal malformations may have higher risk for thoracic inlet fracture and development of obstructive tissue ingrowth. Clinicians should be aware of the possible risk factors for tracheal stent complications.

Angioplasty with versus without routine stent placement for Budd-Chiari syndrome: a randomised controlled trial

Angioplasty recanalisation is recommended as the first-line interventional procedure for Budd-Chiari syndrome, but subsequent restenosis is common. We aimed to test whether use of routine, non-selective stenting in angioplasty could improve patency and treatment efficacy with adequate safety in Budd-Chiari syndrome. We did a randomised controlled trial, for which patients aged 18-75 years with Budd-Chiari syndrome with membranous obstruction or short-length stenosis (≤4 cm), and a Child-Pugh score of less than 13 were considered eligible. Patients were excluded if they had obstruction not amenable to angioplasty, were recommended to be treated with transjugular intrahepatic portosystemic shunt or liver transplantation, or had contraindications for angioplasty. Eligible patients were randomly assigned (1:1) to an angioplasty-only group or an angioplasty plus routine stenting group, with use of a web-based allocation system (Pocock and Simon's minimisation method, stratified by obstruction features and Child-Pugh score). Recanalisation procedures were done within 24 h of randomisation. The statistician and investigators responsible for data collection data and endpoint assessment were masked to group allocation. The primary outcome was the proportion of patients free of restenosis, analysed in the intention-to-treat population. The study is registered on ClinicalTrials.gov (NCT02201485) and is completed. Between July 28, 2014, and Sept 29, 2017, 88 (59%) of 150 screened patients were enrolled and assigned either the angioplasty-only group (n=45) or the angioplasty plus routine stenting group (n=43). During a median follow-up period of 27 months (IQR 19-41), the angioplasty plus routine stenting group had significantly higher proportion of patients free of restenosis (42 [98%] of 43 patients) than did the angioplasty-only group (27 [60%] of 45 patients; p<0·0001). In the survival analysis, 3-year restenosis-free survival was 96·0% (95% CI 88·6-100·0) in the routine stenting group versus 60·4% (46·4-78·7) in the angioplasty-only group (log-rank p<0·0001). The hazard ratio for restenosis was 0·04 (95% CI 0·01-0·31) in favour of routine stenting, with an absolute risk reduction of 35·6% (95% CI 24·2-55·0). Two (5%) patients in the angioplasty plus routine stenting group and one (2%) patient in the angioplasty-only group died during follow-up. One (2%) patient from the angioplasty plus routine stenting group had puncture site haematoma, which was not related to stenting. No stent fracture or migration occurred. Anticoagulation-related adverse events occurred in five (11%) patients from angioplasty alone group and five (12%) patients from angioplasty plus routine stenting group. Routine stenting with angioplasty is superior to angioplasty alone for preventing restenosis in patients with Budd-Chiari syndrome with short-length stenosis and is safe to use as part of first-line invasive treatment. Further validation is needed in similar settings and other regions in which different characteristics of Budd-Chiari syndrome are more prevalent. National Natural Science Foundation of China, National Key Technology R&D Programme, Optimised Overall Project of Shaanxi Province, Boost Programme of Xijing Hospital.

Results from a prospective multicenter feasibility study of Zenith p-Branch stent graft

ObjectiveTo evaluate the Cook Zenith p-Branch stent graft (William A. Cook Australia, Brisbane, Queensland, Australia) for the treatment of patients with asymptomatic juxtarenal or pararenal abdominal aortic aneurysms in a prospective, nonrandomized, multicenter, feasibility study conducted in the United States. MethodsThe off-the-shelf p-Branch endograft incorporates a celiac scallop, superior mesenteric artery (SMA) fenestration, and two conical-shaped pivot renal fenestrations. Patients were eligible if the aneurysm did not extend above the distal margin of the SMA and the anatomy of renal and visceral arteries were compatible with one of the two p-Branch configurations (configuration A, renal fenestrations at the same longitudinal position; configuration B, offset renal fenestration). ResultsA total of 30 patients (93% men; mean age, 73 years; mean aneurysm diameter, 64.7 ± 11.4 mm) were enrolled from January 2013 to June 2015. The mean follow-up period was 28.7 ± 12.5 months (as of October 2017). The technical success rate was 93% (28/30), with technical failure occurring in the first two study cases (device deliberately repositioned below the renal arteries because of difficulty in cannulating the renal arteries in one and an inability to place a renal stent in the other; both patients survived the procedure and withdrew from the study before the 12-month follow-up visit). No additional technical failures occurred after these first two cases, when an updated physician training and proctoring program was implemented. No 30-day mortality occurred. Of the remaining 28 patients, three died during the follow-up period; none within 30 days and none related to the device or procedure as determined by Clinical Events Committee adjudication. No treated aneurysm ruptures, conversion, or core laboratory-reported migration, or stent fracture were reported. The primary renal artery patency (interval to occlusion or reintervention for stenosis) rate was 88.6% ± 4.4% at 1 and 2 years. Two patients (7%) developed renal insufficiency secondary to a right renal artery stenosis in one patient and progression of chronic renal insufficiency in one patient. No patient required dialysis or developed mesenteric ischemia. Of the 28 patients, nine (32%) had undergone 13 secondary interventions for renal artery occlusion (n = 2), SMA occlusion (n = 1), renal or SMA stenosis (5 interventions in 4 patients), renal stent kinking (n = 1), lower extremity claudication (n = 2 in the same patient), type III endoleak between the p-Branch and renal stent (n = 1), and type II endoleak (n = 1). ConclusionsThese early and intermediate results, which incorporated physician learning curves, support the safety and feasibility of the off-the-shelf Zenith p-Branch device. Follow-up examinations through 5 years will continue to assess the long-term results.

Optical coherence tomography characteristics of in-stent restenosis after drug-eluting stent implantation: a novel classification and its clinical significance.

This study aimed to establish a novel classification of in-stent restenosis (ISR) morphological characteristics after drug-eluting stent (DES) implantation as visualized by optical coherence tomography (OCT) and determine its clinical significance. A total of 133 lesions with intrastent restenosis after DES implantation were imaged by OCT. Neointimal tissue characteristics were categorized according to the classical classification as either homogeneous, heterogeneous, or layered. Then all tissues were also classified into six types as follows: homogeneous high-intensity tissue (type I), heterogeneous tissue with signal attenuation (type II), speckled heterogeneous tissue (type III), heterogeneous tissue containing poorly delineated region with invisible strut (type IV), heterogeneous tissue containing sharply delineated low-intensity region (type V), or bright protruding tissue with an irregular surface (type VI). The kappa value for interobserver agreement between the two observers was higher in the modified classification than in the classical classification (0.97 and 0.72, respectively). Most lesions classified as type V and VI were likely to be identified in patients on hemodialysis and located at the ostial right coronary artery. The duration from stent implantation to ISR was significantly longer in types IV and VI than in others. The incidence of stent fracture was significantly higher in types I and IV. This new modified classification enabled us to classify most ISR lesions easily with higher reproducibility. The clinical significance of neointimal restenotic tissue classification by OCT became clear while using the modified classification.

The Fabrication of an Acrylic Repositioning Stent for Use During Intensity Modulated Radiation Therapy: A Feasibility Study.

Radiotherapy is one of the main treatment modalities for head and neck cancers. To minimize damage to normal tissues during radiotherapy, various methods of stabilization have been used, including thermoplastic facemasks and repositioning stents. The goal is to assess the effect of using a customized oral repositioning stent on patient positioning during the course of radiotherapy. Ten consecutive patients scheduled to undergo intensity modulated radiation therapy (IMRT) for cancers of the maxillary sinus, nasal cavity, or oral cavity were recruited to participate in the study (ST group). These patients were matched to 2 retrospective cohorts, one using the original repositioning stent design (OB group), and the other with no stabilization stent (NB group). Hard baseplate wax was used to create a customized wax pattern of the proposed acrylic stent chairside, and processed in heat-cured clear hard acrylic. Relative stability of the daily patient setup was assessed by comparing measurements from surrogate bony landmarks to radiation isocentres obtained from the initial reconstructed planning computed tomograph (CT) to each daily KeV image. There was no stent fracture or distortion throughout treatments, and no patients' treatments were required to be aborted, delayed, or replanned. Mean 3D deviations for the ST, OB, and NB groups were 0.29 ± 0.10 cm, 0.32 ± 0.14 cm, and 0.31 ± 0.13 cm, respectively. The ANOVA test revealed no significant difference in triangulated variations between the treatment groups (F = 0.18, p = 0.84). Patient stability data demonstrated mean vertical, longitudinal, and lateral variations that did not appear different when compared to 2 retrospective cohorts. Although the deviations were not statistically significant between matched cohorts, the added durability of the stent and comfort for patients, without affecting IMRT timeline, are considered clinically significant. By using a customized repositioning stent, it is possible to maintain patient stability comparable to prior protocols and within the range of clinical guidelines, while providing superior comfort and ease of insertion to the patients.

IP115. Bare Metal Stent Fractures in the Superficial Femoral Artery: What Is the Manufacturer and User Facility Device Experience Telling Us?

IP115. Bare Metal Stent Fractures in the Superficial Femoral Artery: What Is the Manufacturer and User Facility Device Experience Telling Us?

Systematic Review and Proportional Meta-Analysis of Endarterectomy and Endovascular Therapy with Routine or Selective Stenting for Common Femoral Artery Atherosclerotic Disease.

Introduction Common femoral endarterectomy (CFE) has been the therapy of choice for common femoral artery atherosclerotic disease (CFA-ASD). In the past, there was inhibition to treat CFA-ASD endovascularly with stents due to fear of stent fracture and compromise of future vascular access site. However, recent advances and new evidence suggest that CFA may no longer be a ‘stent-forbidden zone'. In the light of new evidence, we conducted a meta-analysis to determine the use of endovascular treatment for CFA-ASD and compare it with common femoral endarterectomy in the present era. Methods Using certain MeSH terms we searched multiple databases for studies done on endovascular and surgical treatment of CFA-ASD in the last two decades. Inclusion criteria were randomized control trials, observational, prospective, or retrospective studies evaluating an endovascular treatment or CFE for CFA-ASD. For comparison, studies were grouped based on the treatment strategy used for CFA-ASD: endovascular treatment with selective stenting (EVT-SS), endovascular treatment with routine stenting (EVT-RS), or common femoral endarterectomy (CFE). Primary patency (PP), target lesion revascularization (TLR), and complications were the outcomes studied. We did proportional meta-analysis using a random-effect model due to heterogeneity among the included studies. If confidence intervals of two results do not overlap, then statistical significance is determined. Results Twenty-eight studies met inclusion criteria (7 for EVT-RS, 8 for EVT-SS, and 13 for CFE). Total limbs involved were 2914 (306 in EVT-RS, 678 in EVT-SS, and 1930 in CFE). The pooled PP at 1 year was 84% (95% CI 75-92%) for EVT-RS, 78% (95% CI 69-85%) for EVT-SS, and 93% (95% CI 90-96%) for CFE. PP at maximum follow-up in EVT-RS was 83.7% (95% CI 74-91%) and in CFE group was 88.3% (95% CI 81-94%). The pooled target lesion revascularization (TLR) rate at one year was 8% (95% CI 4-13%) for EVT-RS, 19% (95% CI 14-23%) for EVT-SS, and 4.5% (95% CI 1-9%) for CFE. The pooled rate of local complications for EVT-RS was 5% (95% CI 2-10%), for EVT-SS was 7% (95% CI 3 to 12%), and CFE was 22% (95% CI 14-32%). Mortality at maximum follow-up in CFE group was 23.1% (95% CI 14-33%) and EVT-RS was 5.3% (95% CI 1-11%). Conclusion EVT-RS has comparable one-year PP and TLR as CFE. CFE showed an advantage over EVT-SS for one-year PP. The complication rate is lower in EVT RS and EVT SS compared to CFE. At maximum follow-up, CFE and EVT-RS have similar PP but CFE has a higher mortality. These findings support EVT-RS as a management alternative for CFA-ASD.

Experience with Stent Placement for Benign Pancreaticobiliary Disorders in Children.

Purpose: There is a lack of experience with stenting for benign pancreaticobiliary disorders in children. Materials and Methods: Fifteen children (9 male and 6 female) with a median age of 7.1 years (range 0.7-14.2 years) who underwent treatment with a plastic stent for a benign disorder of the pancreaticobiliary system between May 2003 and September 2017 were recruited to this retrospective study. Results: Biliary and/or pancreatic plastic stents were inserted into 5 patients with congenital, 4 with post-traumatic, and 6 with idiopathic pathologies. Median duration of individual stent placement was 111 days (range 14-1569 days). Eleven children (73%) were treated with one stent only. In 4 cases, up to 22 stents were successively placed over time. There were no complications during stent insertion or stent removal. Seven patients (47%) experienced adverse effects during stenting, including choledocholithiasis, pancreaticolithiasis, cholangitis, acute pancreatitis, stent obstruction, and stent fracture. At follow-up, in 11 cases (73%), the underlying condition was resolved. In 4 children, all of whom suffered from congenital pancreaticobiliary disorders, stent therapy was considered as a temporary treatment before definite surgery. Conclusions: Patients with congenital anomalies of the pancreaticobiliary tree often require surgery for definitive management. However, temporary stent placement can be accomplished safely and successfully and this serves as a bridge to temporize their obstructive process while awaiting surgical intervention. Children with post-traumatic or idiopathic disorders can frequently be managed definitively by stenting alone and many of these require only one single stent insertion.

Stent fracture as a complication of superficial femoral artery stenting – a case report

Stent fracture as a complication of superficial femoral artery stenting – a case report

Stent fracture as a complication of superficial femoral artery stenting – a case report

Stent fracture as a complication of superficial femoral artery stenting – a case report

In Vitro Evaluation of the Gore Viabahn Balloon-Expandable Stent-Graft for Fenestrated Endovascular Aortic Repair

Purpose: To evaluate the safety and integrity of a new stent-graft as a potential bridging device in fenestrated stent-grafts using an in vitro fenestrated model. Materials and Methods: Polyester test sheets with ten 6-mm- or 8-mm-diameter fenestrations were used to simulate a fenestrated main body endoprosthesis. In total, 50 Viabahn balloon-expandable (VBX) stent-grafts of varying lengths (29 and 39 mm) and diameters (6, 7, and 8 mm) were implanted in the fitting fenestrations. After release, the 6- and 7-mm-diameter stent-grafts were flared with a 10×20-mm angioplasty balloon; a 12×20-mm balloon was used in the 8-mm-diameter devices. Safety of the devices was defined as absence of fractures detected on radiography or computed tomography (CT), as well as material failure detected by microscopy and water permeability testing. The forces (in Newtons, N) needed for perpendicular dislocation (pullout force) and axial dislocation (shear stress force) were also evaluated. Results: Forty VBX stent-grafts were subjected to digital radiographic imaging and multiplanar CT. None showed any stent fracture. Subsequent microscopy indicated no damage to the fabric or separation of the graft after flaring. Ten VBX stent-grafts underwent water permeability testing after flaring; no water passed through the graft wall during a 10-minute period under an intraluminal pressure at 120 mm Hg. Testing of 25 VBX stent-grafts revealed initial pullout forces between 11.3 and 31 N. Shear stress tests showed that the average force needed to dislocate the stent-grafts by 50% of their diameter ranged between 5.75 and 6.91 N (mean 6.1±0.5 N) for the 6-mm stents and between 3.31 and 5.4 N (mean 4.4±0.8) for the 8-mm stents. Conclusion: This preliminary study demonstrated the applicability of the VBX as a bridging stent-graft in a simulated fenestration model. A comparison with other stent-grafts and clinical assessment are required.