Unloading and successful treatment with bioresorbable stents during percutaneous coronary intervention:A case report

BACKGROUND With the development of percutaneous coronary intervention(PCI),the number of interventional procedures without implantation,such as bioresorbable stents(BRS)and drug-coated balloons,has increased annually.Metal drug-eluting stent unloading is one of the most common clinical complications.Comparatively,BRS detachment is more concealed and harmful,but has yet to be reported in clinical research.In this study,we report a case of BRS unloading and successful rescue.This is a case of a 59-year-old male with the following medical history:“Type 2 diabetes mellitus”for 2 years,maintained with metformin extended-release tablets,1 g PO BID;“hypertension”for 20 years,with long-term use of metoprolol sustained-release tablets,47.5 mg PO QD;“hyperlipidemia”for 20 years,without regular medication.He was admitted to the emergency department of our hospital due to intermittent chest pain lasting 18 hours,on February 20,2022 at 15:35.Electrocardiogram results showed sinus rhythm,ST-segment elevation in leads I and avL,and poor R-wave progression in leads V1–3.High-sensitivity troponin I level was 4.59 ng/mL,indicating an acute high lateral wall myocardial infarction.The patient’s family requested treatment with BRS,without implanta-tion.During PCI,the BRS became unloaded but was successfully rescued.The patient was followed up for 2 years;he had no episodes of angina pectoris and was in generally good condition.CONCLUSION We describe a case of a 59-year-old male experienced BRS unloading and successful rescue.By analyzing images,the causes of BRS unloading and the treatment plan are discussed to provide insights for BRS release operations.We discuss preventive measures for BRS unloading.

Long-term outcomes of titanium-nitride-oxide coated stents and drug-eluting stents in acute coronary syndrome:A systematic review and meta-analysis

BACKGROUND In severe cases of coronary artery disease,percutaneous coronary intervention provide promising results.The stent used could be a drug-eluting stent(DES)or a titanium-nitride-oxide coated stent(TiNOS).AIM To compare the 5-year effectiveness and safety of the two stent types.METHODS The following systematic review and meta-analysis was conducted in accordance with the preferred reporting items for systematic reviews and meta-analysis guidelines,and PubMed/MEDLINE,Scopus,and Cochrane Central were searched from inception till August 2023.Primary outcomes were major adverse cardiac events(MACE),cardiac death,myocardial infarction(MI),cardiac death or MI,and ischemia-driven total lesion revascularization(ID-TLR).RESULTS Four randomized controlled trials(RCT),which analyzed a sum total of 3045 patients with acute coronary syndrome(ACS)after a median follow-up time of 5 years were included.Though statistically insignificant,an increase in the ID-TLR was observed in patients receiving TiNOSs vs DESs.In addition,MI,cardiac death and MI,and definite stent thrombosis(DST)were significantly decreased in the TiNOS arm.Baseline analysis revealed no significant results with meta-regression presenting non-ST elevated MI(NSTEMI)as a statistically significant covariate in the outcome of MACE.CONCLUSION TiNOS was found to be superior to DES in terms of MI,cardiac death or MI,and DST outcomes,however,the effect of the two stent types on ID-TLR and MACE was not significant.A greater number of studies are required to establish an accurate comparison of patient outcomes in TiNOS and DES.

Safety and efficacy of Kaffes intraductal self-expanding metal stents in the management of post-liver transplant anastomotic strictures

BACKGROUND Endoscopic management is the first-line therapy for post-liver-transplant anas-tomotic strictures.Although the optimal duration of treatment with plastic stents has been reported to be 8-12 months,data on safety and duration for metal stents in this setting is scarce.Due to limited access to endoscopic retrograde cholan-giopancreatography(ERCP)during the coronavirus disease 2019 pandemic in our centre,there was a change in practice towards increased usage and length-of-stay of the Kaffes biliary intraductal self-expanding stent in patients with suitable anatomy.This was mainly due to the theoretical benefit of Kaffes stents allowing for longer indwelling periods compared to the traditional plastic stents.METHODS Adult liver transplant recipients aged 18 years and above who underwent ERCP were retrospectively identified during a 10-year period through a database query.Unplanned admissions post-Kaffes stent insertion were identified manually through electronic and scanned medical records.The main outcome was the incidence of complications when stents were left indwelling for 3 months vs 6 months.Stent efficacy was calculated via rates of stricture recurrence between patients that had stenting courses for≤120 d or>120 d.RESULTS During the study period,a total of 66 ERCPs with Kaffes insertion were performed in 54 patients throughout their stenting course.In 33 ERCPs,the stent was removed or exchanged on a 3-month interval.No pancreatitis,perfor-ations or deaths occurred.Minor post-ERCP complications were similar between the 3-month(abdominal pain and intraductal migration)and 6-month(abdominal pain,septic shower and embedded stent)groups-6.1%vs 9.1%respectively,P=0.40.All strictures resolved at the end of the stenting course,but the stenting course was variable from 3 to 22 months.The recurrence rate for stenting courses lasting for up to 120 d was 71.4%and 21.4%for stenting courses of 121 d or over(P=0.03).There were 28 patients that were treated with a single ERCP with Kaffes,21 with removal after 120 d and 7 within 120 d.There was a significant improvement in stricture recurrence when the Kaffes was removed after 120 d when a single ERCP was used for the entire stenting course(71.0%vs 10.0%,P=0.01).CONCLUSION Utilising a single Kaffes intraductal fully-covered metal stent for at least 4 months is safe and efficacious for the management of post-transplant anastomotic strictures.

Outcomes of a non-randomised audit of single pigtail suture stents in urolithiasis management of Asian patients in Singapore

Objective:Double-J(DJ)ureteric stents are commonly placed perioperatively for semirigid or flexible ureteroscopic renal surgery.It is believed that lesser stent material within the bladder mitigates stent-related symptoms.This study aimed to evaluate the J-Fil ureteral stent,a single pigtail suture stent compared with conventional DJ stent in relation to stent symptoms in an Asian population undergoing ureterorenal intervention.Methods:Based on internal audit committee recommendation approval,the records of 50 patients retrieved,available data of 41 patients who were prospectively enrolled into two groups(Group 1[J-Fil stent group],n=21 and Group 2[DJ stent group],n=20)between August 2020 to January 2021,were analysed.Parameters compared were nature of procedure,stone location and size,ease of deployment or removal,and complications.A modified universal stent symptom questionnaire was used to assess morbidity of stent symptoms within 48 h of insertion and at removal.Results:Both groups had similar median age,distribution in male to female ratio,and stone size.The overall median universal stent symptom questionnaire score at insertion was similar for bladder pain,flank or loin pain,and quality of life between Group 1 and 2;however,at removal Group 1 fared significantly better than Group 2,especially for flank or loin pain and pain at voiding.Both groups had similar ease in insertion with no hospital readmissions.Conclusion:Our audit favoured the single pigtail suture stent in Asian ureters in mitigating stent-related issues.It showed a good safety profile with easy deployment and removal.It promises a new standard in stenting.

Can we predict the incidence of high-grade Clavien-Dindo complications in patients with forgotten encrusted stents undergoing endourologic management?

Objective:Ureteral stents are customarily inserted to facilitate urinary drainage,but they come with their own glitches of being forgotten and/or encrusted leading to serious consequences.The present study aimed to report the complications in patients with forgotten and encrusted stents according to the Clavien-Dindo system specific to urological procedures and identify the factors leading to high-grade(Clavien-Dindo Grade 4A or above)complications.Methods:The hospital records of patients with forgotten encrusted double-J stents over a period of 8 years were reviewed.The parameters recorded included patient demographics,indwelling time,need for percutaneous nephrostomy,hemodialysis,urine culture,blood culture,total blood counts,serum creatinine,radiologic findings,management techniques,number of surgical interventions,modified Clavien-Dindo complications,follow-up,and mortality,if any.Results:Forty patients were included in the study.The median age was 52(range 6-85)years.Of the total,25(62.5%)patients had a“significant”stent load;31(77.5%)had renal failure or acute kidney injury on presentation;19(47.5%)patients had sepsis at presentation.Among the patients presented with sepsis,11(57.9%)patients demonstrated a positive urine culture;and 7/11(63.6%)patients exhibited pan-resistant organisms.Twelve out of 40(30.0%)patients in our series developed high-grade Clavien-Dindo complications.On univariate analysis,sepsis at presentation(p=0.007),stent load(p=0.031),diabetes(p=0.023),positive urine culture(p=0.007),and stent indwelling time of more than 1 year(p=0.031)were found to be significant.On multivariate logistic regression analysis,sepsis at presentation(p=0.017)and positive urine culture(p=0.016)were significant predictors for high-grade complications.Conclusion:It is prudent to identify specific risk factors,namely sepsis at presentation and positive urine culture to triage and optimize these patients before surgical management.

Defining failure of endoluminal biliary drainage in the era of endoscopic ultrasound and lumen apposing metal stents

The role of endoscopy in pathologies of the bile duct and gallbladder has seen notable advancements over the past two decades.With advancements in stent technology,such as the development of lumen-apposing metal stents,and adoption of endoscopic ultrasound and electrosurgical principles in therapeutic endoscopy,what was once considered endoscopic failure has transformed into failure of an approach that could be salvaged by a second-or third-line endoscopic strategy.Incorporation of these advancements in routine patient care will require formal training and multidisciplinary acceptance of established techniques and collaboration for advancement of experimental techniques to generate robust evidence that can be utilized to serve patients to the best of our ability.

Revolutionizing palliative care:Electrocautery-enhanced lumenapposing metal stents in endoscopic-ultrasound-guided biliary drainage for malignant obstructions

Patients with malignant biliary obstruction,following endoscopic retrograde cholangiopancreatography(ERCP)failure could be referred for endoscopicultrasound-guided biliary drainage through electrocautery-enhanced(ECE)lumen-apposing metal stent(LAMS)placement.However,the efficacy and safety of ECE-LAMS in this scenario have remained debatable due to minimal scientific evidence.The current confirmed 91.0%clinical success,96.7%technical success,7.3%reintervention rate,and 17.5%adverse events,following the treatment of malignant biliary obstruction with ECE-LAMS delivery.Finally,ECE-LAMS proved to be a generalizable strategy for managing biliary obstruction for patients who were excluded from ERCP.

Unveiling the potential of electrocautery-enhanced lumen-apposing metal stents in endoscopic ultrasound-guided biliary drainage

This editorial delves into Peng et al's article,published in the World Journal of Gastrointestinal Surgery.Peng et al's meta-analysis investigates the effectiveness of electrocautery-enhanced lumen-apposing metal stents(ECE-LAMS)in ultrasound-guided biliary drainage for alleviating malignant biliary obstruction.Examining 14 studies encompassing 620 participants,the research underscores a robust technical success rate of 96.7%,highlighting the efficacy of ECE-LAMS,particularly in challenging cases which have failed endoscopic retrograde cholangio pancreatography.A clinical success rate of 91.0% underscores its impact on symptom alleviation,while a reasonably tolerable adverse event rate of 17.5% is observed.However,the 7.3% re-intervention rate stresses the need for post-procedural monitoring.Subgroup analyses validate consistent outcomes,bolstering the applicability of ECE-LAMS.These findings advocate for the adoption of ECELAMS as an appropriate approach for biliary palliation,urging further exploration in real-world clinical contexts.They offer valuable insights for optimizing interventions targeting malignant biliary obstruction management.

Research on the Status Quo and Optimization of Centralized Procurement of Coronary Stents

Objective To study the impact of the first national centralized procurement of coronary stents on patients’psychology,the economy of medical institutions,and the survival and development of the coronary stents industry,and to provide suggestions on perfecting procedures to better carry out the centralized procurement of coronary stents.Methods Literature analysis was used to investigate the results of the procurement of coronary stent in a province and a hospital.Results and Conclusion The centralized procurement of coronary stents has alleviated the economic pressure of patients,but it has many problems.Therefore,this paper proposes some suggestions,such as promoting the orderly development of the coronary stent industry,improving the evaluation link of the centralized procurement of coronary stents,adopting the accurate reporting model to ensure the quality of coronary stents and improving the standardization of clinical services.

Oncologic impact of colonic stents for obstructive left-sided colon cancer

Colonic stenting has had a significant positive impact on the management of obstructive left-sided colon cancer(OLCC) in terms of both palliative treatment and bridge-to-surgery(BTS). Notably, many studies have convincingly demonstrated the effectiveness of stenting as a BTS, resulting in improvements in shortterm outcomes and quality of life, safety, and efficacy in subsequent curative surgery, and increased cost-effectiveness, whereas the safety of chemotherapy after stenting and the long-term outcomes of stenting as a BTS are controversial. Several studies have suggested an increased risk of perforation in patients receiving bevacizumab chemotherapy after colonic stenting. In addition, several pathological analyses have suggested a negative oncological impact of colonic stenting. In contrast, many recent studies have demonstrated that colonic stenting for OLCC does not negatively impact the safety of chemotherapy or long-term oncological outcomes. The updated version of the European Society of Gastrointestinal Endoscopy guidelines released in 2020 included colonic stenting as a BTS for OLCC as a recommended treatment. It should be noted that the experience of endoscopists is involved in determining technical and clinical success rates and possibly oncological outcomes. This review discusses the positive and negative impacts of colonic stenting on OLCC treatment, particularly in terms of oncology.

Real-world five-year outcomes of FlexyRap®cobalt-chromium rapamycin-eluting stents with biodegradable polymer in patients with de-novo coronary artery disease

BACKGROUND The use of biodegradable polymer drug-eluting stents(BP-DES)has been proven to minimize restenosis and stent thrombosis.The current post-marketing monitoring was observed at the 5-year clinical outcomes of individuals who had been treated with FlexyRap®DES in the real world.AIM To assess the safety and effectiveness of FlexyRap®DES at the 5-year follow-up in real-world settings.METHODS Findings from a retrospective,multi-center,observational,post-market clinical follow-up study of patients treated with FlexyRap®DES for de novo coronary artery disease(CAD)were reported.During the 12-mo follow-up,the primary endpoint was target lesion failure,which was defined as the composite of cardiovascular death, target vessel myocardial infarction(TV-MI), and clinically driven target lesion revascularization.RESULTS The data of 500 patients received with FlexyRap®DES was obtained at the completion of the surveillance timeline of 5-year.After the implantation of FlexyRap®DES,the device success rate was 100%.Adverse events that led to major bleeding,permanent disability,or death were not experienced in the patients.The major adverse cardiac event rate at 12-mo,3-year,and 5-year follow-up was 1(0.2%),0(0%),and 1(0.2%)respectively with 0(0%)cardiovascular death,2(0.4%)TV-MI,and 0(0%)TLR compositely.Furthermore,late stent thrombosis was found in 2(0.4%)patients at the follow-up of 12-mo,very late stent thrombosis was observed in 2 patients(0.4%)at 3-year follow-up.CONCLUSION FlexyRap®DES was proved to be safe and efficacious in real-world patients with de novo CAD,indicating a lowered rate of cardiac events and stent thrombosis at 5-year follow-up.

Image-based visualization of stents in mechanical thrombectomy for acute ischemic stroke:Preliminary findings from a series of cases

BACKGROUND Mechanical thrombectomy is the most effective treatment for great cerebral artery embolization within a set time window.Typically,an arteriogram does not show the localization of the stent after release and whether a thrombus is captured or not.Thus,improving the visualization of a stent in interventional therapy will be helpful for clinicians.AIM To analyze stent imaging findings to enhance clinicians’understanding of a special circumstance,wherein a Solitaire AB retrievable stent was visible during the imaging of a thrombus capture that improved the success rate of stent-based mechanical thrombectomy.METHODS This was a retrospective study with four acute ischemic stroke(AIS)patients who underwent stent-based mechanical thrombectomy.RESULTS Patient 1 was a 64-year-old man admitted after 5 h of confusion;angiography revealed basilar artery occlusion.We inserted a stent into the left posterior cerebral artery-P2 segment and visualized the expanded stent that successfully captured a thrombus.Patient 2 was a 74-year-old man admitted with confusion,which lasted approximately 3 h.Angiography revealed a left middle cerebral artery(MCA)-M1 segment occlusion.A stent was deployed in the distal M2 segment,and we could visualize the stent by capturing the thrombus.Patient 3 was a 74-year-old woman admitted after experiencing left hemiplegia for 3 h.We deployed a stent at the distal right MCAM2 segment,and the developing stent captured a large thrombus.Patient 4 was an 82-year-old man who presented with confusion for 3 h.A developing stent was placed in the distal left MCA-M1 segment,which captured a large thrombus and several fragmented thrombi.CONCLUSION To the best of our knowledge,this is the first report of stent imaging in patients with AIS.We demonstrated the usefulness and substantial potential of stent imaging in stent-based mechanical thrombectomy for AIS.

Drug-eluting stents and acute myocardial infarction:A lethal combination or friends?

Primary percutaneous coronary intervention is the preferred reperfusion strategy for patients presenting with ST-segment elevation myocardial infarction(STEMI). First generation drug-eluting stents(DES),(sirolimus drug-eluting stents and paclitaxel drug-eluting stents), reduce the risk of restenosis and target vessel revascularization compared to bare metal stents. However, stent thrombosis emerged as a major safety concern with first generation DES. In response to these safety issues, second generation DES were developed with different drugs, improved stent platforms and more biocompatible durable or bioabsorbable polymeric coating. This article presents an overview of safety and efficacy of the first and second generation DES in STEMI.

Association of Comorbid Asthma and the Efficacy of Bioabsorbable Steroid-eluting Sinus Stents Implanted After Endoscopic Sinus Surgery in Patients with Chronic Rhinosinusitis with Nasal Polyps

Objective To identify factors affecting the efficacy of steroid-eluting sinus stents implanted after endoscopic sinus surgery(ESS)in patients with chronic rhinosinusitis with nasal polyps(CRSwNP).Methods We performed a post-hoc analysis of a randomized self-controlled clinical trial on post-operative implantation of bioabsorbable steroid-eluting stents in patients with CRSwNP.Univariate logistic regression analysis was conducted to identify which of the following factors affect the response to post-operative stent implantation:sex,serum eosinophil levels,history of prior surgery,endoscopic scores,and comorbid conditions(asthma and allergic rhinitis).The primary outcome was the rate of post-operative intervention on day 30,and the secondary outcome was the rate of polypoid tissue formation(grades 2–3)on days 14,30,and 90.Results A total of 151 patients with CRSwNP were included in the post-hoc analysis.Asthma was identified as the only risk factor for a poor response to steroid-eluting sinus stents on post-operative day 30,with an odds ratio of 23.71(95%CI,2.81,200.16;P=0.004)for the need for post-operative intervention and 19(95%CI,2.20,164.16;P=0.003)for moderate-to-severe polypoid tissue formation.In addition,the asthmatic group showed higher rates of post-operative intervention and polypoid tissue formation than the non-asthmatic group on post-operative day 30.Blood eosinophil levels were not identified as a risk factor for poor outcomes after stent implantation.Conclusion Comorbid asthma,but not blood eosinophil level,impairs the efficacy of steroid-eluting sinus stents in the short term after ESS in patients with CRSwNP.

Rational design, synthesis and prospect of biodegradable magnesium alloy vascular stents

Biodegradable magnesium(Mg) alloys are expected to be promising materials for cardiovascular stents(CVS), which can avoid the longterm clinical problems of current CVS, such as in-stent restenosis, late stent thrombosis, etc. Mg alloy stents exhibit superior biocompatibility and tunable biodegradability, compared with conventional permanent metallic stents. However, the poor formability and non-uniform corrosion of Mg alloy stents hinder their clinical application of CVS. This review focuses on the development of Mg alloys for CVS in recent years.According to the results of bibliometric analysis, we analyzed different biodegradable Mg alloy systems. Moreover, the structural design strategies for Mg alloy stents that can reduce the stress concentration, as well as the surface modification methods to control the corrosion behavior and biological performance of Mg alloy stents are also highlighted. At last, this review systematically discussed the potential directions and challenges of biodegradable magnesium stents(BMgS) in cardiovascular fields.

Outcomes of colon self-expandable metal stents for malignant vs benign indications at a tertiary care center and review of literature

BACKGROUND Endoscopic placement of a self-expandable metal stent(SEMS)is a minimally invasive treatment for use in malignant and benign colonic obstruction.However,their widespread use is still limited with a nationwide analysis showing only 5.4%of patients with colon obstruction undergoing stent placement.This underutilization could be due to perceived increase risk of complications with stent placement.AIM To review long-and short-term clinical success of SEMS use for colonic obstruction at our center.METHODS We retrospectively reviewed all the patients who underwent colonic SEMS placement over aeighteen year period (August 2004 through August 2022) at our academic center. Demographicsincluding age, gender, indication (malignant and benign), technical success, clinical success,complications (perforation, stent migration), mortality, and outcomes were recorded.RESULTSSixty three patients underwent colon SEMS over an 18-year period. Fifty-five cases were formalignant indications, 8 were for benign conditions. The benign strictures included diverticulardisease stricturing (n = 4), fistula closure (n = 2), extrinsic fibroid compression (n = 1), and ischemicstricture (n = 1). Forty-three of the malignant cases were due to intrinsic obstruction from primaryor recurrent colon cancer;12 were from extrinsic compression. Fifty-four strictures occurred on theleft side, 3 occurred on the right and the rest in transverse colon. The total malignant case (n = 55)procedural success rate was 95% vs 100% for benign cases (P = 1.0, NS). Overall complication ratewas significantly higher for benign group: Four complications were observed in the malignantgroup (stent migration, restenosis) vs 2 of 8 (25%) for benign obstruction (1-perforation, 1-stentmigration) (P = 0.02). When stratifying complications of perforation and stent migration there wasno significant difference between the two groups (P = 0.14, NS).CONCLUSIONColon SEMS remains a worthwhile option for colonic obstruction related to malignancy and has ahigh procedural and clinical success rate. Benign indications for SEMS placement appear to havesimilar success to malignant. While there appears to be a higher overall complication rate inbenign cases, our study is limited by sample size. When evaluating for perforation alone theredoes not appear to be any significant difference between the two groups. SEMS placement may bea practical option for indications other that malignant obstruction. Interventional endoscopistsshould be aware and discuss the risk for complications in setting of benign conditions. Indicationsin these cases should be discussed in a multi-disciplinary fashion with colorectal surgery.

Research progress and future development trends of venous sinus stents

Venous sinus stent implantation is an emerging endovascular treatment technique effectively applied in diseases such as cerebral venous sinus thrombosis.However,arterial stents are commonly used in clinical practice for venous sinus stent implantation,which is off-label and carries high risks and poor prognosis,highlighting the necessity of developing venous sinus-specific stents.This narrative review discusses the current situation and problems of venous sinus stent implantation and looks forward to the design focus and future development prospects of venous sinus-specific stents.

Fully covered metal biliary stents: A review of the literature

Fully covered self-expandable metal stents(FCSEMS)represent the latest advancement of metal biliary stents used to endoscopically treat a variety of obstructive biliary pathology.A large stent diameter and synthetic covering over the tubular mesh prolong stent patency and reduce risk for tissue hyperplasia and tumor ingrowth.Additionally,FCSEMS can be easily removed.All these features address issues faced by plastic and uncovered metal stents.The purpose of this paper is to comprehensively review the application of FCSEMS in benign and malignant biliary strictures,biliary leak,and post-sphincterotomy bleeding.

Self-expanding metallic esophageal stents:A long way to go before a particular stent can be recommended

We agree that the covered self-expanding metal stents (SEMSs) fare better than the uncovered stents as recurrent dysphagia due to tumor ingrowth is common with uncovered stent. Recent American College of Gastroenterology Practice Guideline on the Role of Esophageal Stents in Benign and Malignant Diseases concludes that SEMSs cannot be routinely recommended in conjunction with chemo-radiation. The comparison of ultraflex and choostent in the Italian study found no difference in the palliation of dysphagia, rate of complications and survival rate.

Fatigue Performance of Fabrics of Stent-Grafts Supported with Z-Stents vs. Ringed Stents

Stent-grafts were commercialized rapidly and gained a broad clinical acceptance over the past two decades. However,relatively more recent recognition of particular stent-graft design shortcomings have been identified which need to be addressed. It appears that various stent-graft designs may be more or less resistant to metal fatigue and /or fabric abrasions which can lead to type III and type IV endoleaks over the long term. Therefore,it is necessary to investigate the fatigue performance of the most common stentgraft designs: Z-stents and ringed stents,in a long-term in vitro fatigue simulation environment. This paper aimed to analyze nondestructively( gross observations) and destructively( fabric characteristics,mechanical and chemical properties) in order to put forward suggestions to improve the fabric and stent characteristics that may prevent type III and IV endoleaks. The fabric supported with ringed stent-grafts remained nearly completely intact after 168h. However, the fabric supported with Z-stents demonstrated significant damage. Fabric characteristics and tensile strength of the fibers did not present a significant difference between the control and fatigue simulated specimens. The crystallinity declined for both specimens. The fatigue performance of fabrics supported with ringed stents appears to be superior to that supported with Z-stents. The potential for a dynamic and destructive interaction between the apices of Z-stents which can lead to fraying and /or tearing of the graft fabric must be addressed in future designs.