Clinical Value of the Quantitative Flow Ratio to Predict Long-term Target Vessel Failure in Patients with In-stent Restenosis after Drug-coated Balloon Angioplasty

Objective The study sought to investigate the clinical predictive value of quantitative flow ratio(QFR)for the long-term target vessel failure(TVF)outcome in patients with in-stent restenosis(ISR)by using drug-coated balloon(DCB)treatment after a long-term follow-up.Methods This was a retrospective study.A total of 186 patients who underwent DCB angioplasty for ISR in two hospitals from March 2014 to September 2019 were enrolled.The QFR of the entire target vessel was measured offline.The primary endpoint was TVF,including target vessel-cardiac death(TV-CD),target vessel-myocardial infarction(TV-MI),and clinically driven-target vessel revascularization(CD-TVR).Results The follow-up time was 3.09±1.53 years,and 50 patients had TVF.The QFR immediately after percutaneous coronary intervention(PCI)was significantly lower in the TVF group than in the no-TVF group.Multivariable Cox regression analysis indicated that the QFR immediately after PCI was an excellent predictor for TVF after the long-term follow-up[hazard ratio(HR):5.15×10−5(6.13×10−8−0.043);P<0.01].Receiver-operating characteristic(ROC)curve analysis demonstrated that the optimal cut-off value of the QFR immediately after PCI for predicting the long-term TVF was 0.925(area under the curve:0.886,95%confidence interval:0.834–0.938;sensitivity:83.40%,specificity:88.00;P<0.01).In addition,QFR≤0.925 post-PCI was strongly correlated with the TVF,including TV-MI and CD-TVR(P<0.01).Conclusion The QFR immediately after PCI showed a high predictive value of TVF after a long-term follow-up in ISR patients who underwent DCB angioplasty.A lower QFR immediately after PCI was associated with a worse TVF outcome.

Ascophyllum nodosum and Fucus vesiculosus ameliorate restenosis via improving inflammation and regulating the PTEN/PI3K/AKT signaling pathway

Restenosis is a common complication following coronary angioplasty.The traditional use of seaweeds for health benefits has increasingly been explored,however few studies exist reporting its protective effects on the development of restenosis and gut dysbiosis.The aim of this study was to investigate the potential of seaweed extracts(SE) of Ascophyllum nodosum and Fucus vesiculosus in inhibiting intimal hyperplasia in a rat model of restenosis and its underlying mechanisms in macrophages and vascular smooth muscle cells(vSMCs).16S rRNA sequencing was done to investigate the regulatory effect of SE on the gut microbiome of injured rats.As indicated by the results,SE significantly inhibited the progression of intimal hyperplasia in vivo,attenuated inflammation in macrophages and could inhibit the proliferation,dedifferentiation and migration of vSMCs.It was observed through immunoblotting assays that treatment with SE significantly upregulated PTEN expression in macrophages and inhibited the upregulation of PI3K and AKT expression in vSMCs.Meanwhile,according to the 16S rRNA gene sequencing analysis,supplementation with SE modulated gut microbiota composition in injured rats.In conclusion,SE could ameliorate intimal hyperplasia by inhibiting inflammation and vSMCs proliferation through the regulation of the PTEN/PI3K/AKT pathway and modulating the gut microbiome.

Diagnosis and management challenges of in-stent restenosis in coronary arteries

Over the course of the 3 decades, percutaneous coronary intervention(PCI) with stent implantation transformed the practice of cardiology. PCI with stenting is currently the most widely performed procedure for the treatment of symptomatic coronary disease. In large trials, drugeluting stents(DES) have led to a significant reduction in in-stent restenosis(ISR) rates, one of the major limitations of bare-metal stents. Due to these favorable findings, DES was rapidly and widely adopted enabling more complex coronary interventions. Nevertheless, ISR remains a serious concern as late stent complications. ISR mainly results from aggressive neointimal proliferation and neoatherosclerosis. DES-ISR treatment continues to be challenging complications for interventional cardiologists.

Treatment of coronary in-stent restenosis： a systematic review

冠的 stent 培植显著地改进了经皮的冠的干预并且启用了平凡汽球 angioplasty 的早复杂并发症的管理。然而，新复杂并发症伴随了这些改进：从 neointimal 增生产生的 in-stent 狭窄(ISR ) 。在冠的 angioplasty 以后的 ISR 当前是这个方法的主要限制之一，导致 exertional 心绞痛或急性冠的症候群的复发。在赤裸金属的 stent (BMS ) 以后的 ISR 的临床的发生培植是近似 20%-35% 。drug-eluting stents (DES ) 的使用在 ISR 的出现导致了进一步的减少到 5%-10% 。源于控制临床的研究的证据建议 DES 和 drug-eluting 汽球导管(初上舞台的人) 提供临床的最好， angiographic 导致 ISR 的处理。我们为 BMS-ISR 和 DES-ISR 拿了 pathophysiology，诊断和处理选择的系统的评论。我们讨论最近的 randomised 研究，比较为新 biovascular scafolds 和 scafold 狭窄的话题的 BMS 或 DES-ISR 处理，以及使用使用的不同 DES 或初上舞台的人。

Matrix metalloproteinase 9 level as an indicator for restenosis following cervical and intracranial angioplasty and stenting

Cervical and intracranial angioplasty and stenting is an effective and safe method of reducing the risk of ischemic stroke, but it may be affected by in-stent restenosis. The present study in-vestigated serum level of matrix metalloproteinase 9 as a predictor of restenosis after 40 patients underwent cervical and/or intracranial angioplasty and stenting. Results showed that resteno-sis occurred in 30% （3/10） of patients when the serum level of matrix metalloproteinase 9 at 3 days after surgery was 2.5 times higher than preoperative level. No restenosis occurred when the serum level of matrix metalloproteinase 9 at 3 days after surgery was not 2.5 times higher than preoperative level. Restenosis occurred in 12% （2/17） of patients when the serum level of matrix metalloproteinase 9 was higher than preoperative level for more than 30 days after surgery, but only occurred in 4% （1/23） of patients when the serum level of matrix metalloproteinase 9 was higher than preoperative level for less than 30 days after surgery. However, the differences observed were not statistically signiifcant （P 〉 0.05）. Experimental ifndings indicate that when the serum level of matrix metalloproteinase 9 is 2.5 times higher than preoperative level at 3 days after cervi-cal and intracranial angioplasty and stenting, it may serve as a predictor of in-stent restenosis.

Influence of increased epicardial adipose tissue volume on 1-year in-stent restenosis in patients who received coronary stent implantation

Epicardial 脂肪质的织物(吃) 显著地与冠的动脉粥样硬化患者匾，心脏的事件和冠的心疾病的临床的预后的形成和作文被联系。但是，是否增加了吃免职可以影响 in-stent 狭窄(ISR ) 的发生当前是不清楚的。这研究把冠的计算断层摄影术 angiography ( CCTA )用作一个平均数调查是否增加了吃体积与为怀疑的冠的动脉疾病的评估经历了64片 CCTA 检查的 364 个病人全部的 ISR.MethodsA 被联系，并且随后第一次经历了经皮的冠的干预(一种总线标准)，然后为一年里的 ISR 检查的接受冠的 angiography ( CA )后续，回顾地在这研究被包括。吃体积被 CCTA 检查测量。CA 后续在 9 和 15 个月之间被获得。ISR 作为 stent 片断或 peri-stent 片断变窄的 50% 钠直径是 dened。吃体积有或没有 ISR 在病人之间被比较， ISR 的另外的著名预言者是 compared.ResultsEAT 没有 ISR ，体积 signicantly 与那些相比与 ISR 在病人被增加( 154.5 ?潃据畬楳湯??汥敤汲?华??千瀠瑡敩瑮?楷桴???瑳条摥倠?洠杩?戠?湡漠瑰浩污猠牴瑡来?獡潳楣瑡摥眠瑩?敲畤散?潬杮琭牥?慣摲慩?敤瑡?牯??潣灭牡摥眠瑩?湯?楴敭倠?猠牴瑡来?

Drug-eluting balloons versus new generation drug-eluting stents for the management of in-stent restenosis: an updated meta-analysis of randomized studies

Background New-generation drug-eluting stents (DES) was more effective in the treatment of in-stent restenosis (ISR) compared with the first-generation DES. Drug-eluting balloons (DEB) and new-generation DES had been available strategies in treatment of bare-metal stents/DES ISR (BMS/DES-ISR). Six new randomized trials have recently examined the angiographic outcomes and one-year clinical outcomes of DEB and new generation DES in BMS/DES-ISR. However, the optimal management for BMS/DES-ISR lesions remains controversial. Methods We searched the randomized clinical trials evaluating the angiographic outcomes and one-year clinical outcomes of DEB and new-generation DES in patients with BMS/DES-ISR. The primary endpoints were the angiographic outcomes, including the minimal luminal diameter (MLD), diameter stenosis %(DS%), late lumen loss (LLL), and binary restenosis (BR). Results A total of six randomized clinical trials with 1177 BMS/DES-ISR patients were included in our meta-analysis. For angiographic outcomes, there were significantly less MLD and more DS% with DEB compared to new-generation DES (MLD: MD =?0.18, 95% CI:?0.31– ?0.04, P < 0.001;DS%: MD = 5.68, 95% CI: 1.00–10.37, P < 0.001). Moreover, for one-year clinical outcomes, DEB was associated with a significant increase risk in target lesion revascularization (TLR)(RR = 2.93, 95% CI: 1.50–5.72, P = 0.002). However, DEB was associated with higher risks of major adverse cardiac event, target vessel revascularization, TLR, BR, and more DS% only in DES-ISR group. Conclusions DEB and new-generation DES have the similar clinical efficacy for the treatment of BMS-ISR. However, DES showed more MLD, less DS%, and a decreased risk of TLR for the treatment of DES-ISR.

New predictors of in-stent restenosis in patients with diabetes mellitus undergoing percutaneous coronary intervention with drug-eluting stent

BackgroundPercutaneous 冠的干预(一种总线标准) 为冠的动脉疾病(CAD ) 成为了主要治疗学的过程，但是 in-stent 狭窄(ISR ) 的高率在临床的实践仍然是一个未解决的临床的问题。增加的证据建议糖尿病 mellitus (DM ) 是为 ISR，而是在有 DM 的 CAD 病人的 ISR 的风险预言者的一个主要风险因素一直不好描绘。这研究的目的是调查临床并且 angiographic 特征预言者显著地在与 drug-eluting stent ( DES )跟随冠的 stenting 的糖尿病的病人与 ISR 的出现联系了诊断了 CAD 并且在北京 Anzhen 经历了冠的 DES 培植的有糖尿病的 920 个病人的 .MethodsA 总数在中国的医院连续地从2012年1月注册了到2012年12月。这些， 440 个病人由于对待的目标损害的前进在 6 个月以内经历了第二 angiography。最后，满足了包括和排除标准的 368 个这些病人被跟随在上面由在基线一种总线标准以后的 angiography。根据是否 ISR 在后续 angiography 被检测，病人们被划分成 ISR 组(n = 74 ) 并且 non-ISR 组(n = 294 ) 。在有 DM 的病人的 ISR 的独立预言者被有一个平均数的 368 个病人(260 个女人和 108 个男人) 全部的回归 models.ResultsA 58.71 变老的 multivariate 艇长比例的危险探索#

Recent advances in cardiovascular stent for treatment of in-stent restenosis:Mechanisms and strategies

Treatments of atherogenesis,one of the most common cardiovascular diseases(CVD),are continuously being made thanks to innovation and an increasingly in-depth knowledge of percutaneous transluminal coronary angioplasty(PTCA),the most revolutionary medical procedure used for vascular restoration.Combined with an expanding balloon,vascular stents used at stricture sites enable the long-time restoration of vascular permeability.However,complication after stenting,in-stent restenosis(ISR),hinders the advancement of vascular stents and are associated with high medical costs for patients for decades years.Thus,the development of a high biocompatibility stent with improved safety and efficiency is urgently needed.This review provides an overview of current advances and potential technologies for the modification of stents for better treatment and prevention of ISR.In particular,the mechanisms of in-stent restenosis are investigated and summarized with the aim to comprehensively understanding the pathogenesis of stent complications.Then,according to different therapeutic functions,the current stent modification strategies are reviewed,including polymeric drug eluting stents,biological friendly stents,prohealing stents,and gene stents.Finally,the review provides an outlook of the challenges in the design of stents with optimal properties.Therefore,this review is a valuable and practical guideline for the development of cardiovascular stents.

Restenosis of a drug eluting stent on the previous bioresorbable vascular scaffold successfully treated with a drug-coated balloon: A case report

BACKGROUND The in-stent restenosis(ISR)rates are reportedly inconsistent despite the increased use of second-generation drug eluting stent(DES).Although bioresorbable vascular scaffold(BVS)have substantial advantages with respect to vascular restoration,the rate of scaffold thrombosis is higher with BVS than with DES.Optimal treatment strategies have not been established for DES-ISR to date.CASE SUMMARY We report on a case of a 60-year-old man patient with acute coronary syndrome.He had a history of ST-segment elevation myocardial infarction associated with very late scaffold thrombosis and treated with a DES.Coronary angiography revealed significant stenosis,suggesting DES-ISR on the previous BVS.Optical coherence tomography(OCT)identified a plaque rupture and a disrupted scaffold strut in the neointimal proliferation of DES.To treat the DES-ISR on the previous BVS,we opted for a drug-coated balloon(DCB)after a balloon angioplasty using a semi-compliant and non-compliant balloon.The patient did not experience adverse cardiovascular events on using a DCB following the use of intensive dual antiplatelet therapy and statin for 24 mo.CONCLUSION This case highlights the importance of OCT as an imaging modality for characterizing the mechanism of target lesion failure.The use of a DCB following the administration of optimal pharmacologic therapy may be an optimal strategy for the treatment and prevention of recurrent BVS thrombosis and DES-ISR.

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.

Volumetric intravascular ultrasound comparisons of drug-eluting stent thrombosis and in-stent restenosis

Objectives We compared intravascular ultrasound (IVUS) findings of drug-eluting stent (DES)-treated lesions that developed stent thrombosis versus in-stent restenosis (ISR) to identify underlying mechanical differences. Methods IVUS findings in 15 post-DES thrombosis patients were compared with 45 matched ISR patients who had no evidence of stent thrombosis. Results Minimum stent area [MSA, (3.7±0.8) mm2 vs (4.9±1.8) mm2, P=0.01], minimum stent diameter [(1.9±0.3) mm vs (2.3±0.4) mm, P=0.005], mean stent area [(5.2±0.8) mm2 vs (7.2±2.1) mm2, P【0.01], and both focal [MSA/reference lumen area, (54.7±15.9)% vs (75.0±20.1)%, P=0.001] and diffuse stent expansion [mean stent area/reference lumen area, (76.6±23.0)% vs (110.3±23.3)%, P【0.01] were significantly smaller in the stent thrombosis group (vs the ISR group). An MSA 【4.0 mm2 (73.3% vs 35.6%, P=0.01) or 【5.0 mm2 (86.7% vs 53.3%, P=0.02) was more often found in the stent thrombosis group (vs the ISR group). The MSA site occurred more frequently in the proximal stent segment within the stent thrombosis group compared to the ISR group (60% vs 24.4%, P=0.01). There were no differences in edge dissection, stent fracture, or stent-vessel wall malapposition between the two groups. Independent predictors of stent thrombosis were diffuse stent expansion (OR=1.5, P=0.03) and proximal location of the MSA site (OR=12.7, P=0.04). Conclusion DES-treated lesions that develop thrombosis or restenosis are often underexpanded. Underexpansion appears to be more severe in DES-thrombosis lesions. Lesions with diffuse underexpansion and a proximal (vs distal) underexpanded MSA site are more predisposed to thrombus formation than ISR.

The optimal stent pusher position to achieve successful ureteral stent insertion under fluoroscopic guidance

Objective: To examine factors to predict the optimal stent pusher position when inserting ureteral stents under fluoroscopy.Methods: We retrospectively reviewed 327 patients who underwent ureteral stent insertion. We considered the pubic bone as a useful anatomical landmark to insert ureteral stents under fluoroscopic guidance. Thus, we categorized patients into three groups (proximal, middle, and distal groups) according to the position of the radiopaque tip of the push catheter when inserting the ureteral stent. Success was defined as a completely curled ureteral stent tail. We compared stent insertion success rates among the three groups. A multivariate analysis was performed to identify the factors affecting stent insertion success.Results: In men, 36 (63.2%) cases were deemed successful in the proximal group compared with 40 (80.0%) cases in the middle group and 12 (20.7%) cases in the distal group (p<0.001). In women, 26 (45.6%) cases were deemed successful in the proximal group compared with 54 (98.2%) cases in the middle group and 38 (76.0%) cases in the distal group (p<0.001). With the multivariate analysis, the stent pusher position was the most significant factor influencing successful stent insertion (men: odds ratio 6.00, 95% confidence interval 2.66-13.51, p<0.001;women: odds ratio 37.80, 95% confidence interval 4.94-289.22, p<0.001).Conclusion: The position of the stent pusher affects stent insertion success. The middle of the pubic symphysis is the optimal position for the radiopaque tip of the pusher when inserting ureteral stents under fluoroscopic guidance.

Incidence, Predictors, Treatment, and Long-Term Prognosis of Patients with Restenosis after Long Drug-Eluting Stent Implantation for Coronary Arteries

Background: Few data on the clinical course and management of patients experiencing restenosis after implantation of long drug-eluting stents treatment for coronary arteries was available. Objectives: The aim of this study was to evaluate the incidence, predictors, and long-term outcomes of patients with in-stent restenosis (ISR) after percutaneous coronary intervention (PCI) with long (33 mm & 38 mm) drug-eluting stents (DES) for long lesions in coronary arteries including left anterior descending artery (LAD), Lt circumflex artery (Lt Cx), right coronary artery (RCA), obtuse marginal artery (OM) & posterior descending artery (PDA). Methods: Between July 2009 and October 2010, 421 long DES had being implanted in 421 consecutive patients with significant coronary artery stenosis, with 371 patients (88%) undergoing routine follow up, clinical follow up done by exercise stress test at 6 & 12 months after stenting for 126 patients (34%), in 124 patients (33.5%) follow up was done by Computed Tomography angiography & 121 patients (32.5%) with clinically driven angiographic follow-up. A major adverse cardiac event was defined as the composite of death, myocardial infarction (MI), or target-lesion revascularization (TLR) within 15 months. Results: All patients who underwent clinical follow up were asymptomatic. The overall incidence of angiographic (CT or conventional) ISR with long (33 mm & 38 mm) DES was 4% (15 out of 371 stents) with 8 (53.3%) focal-type and 7 (46.7%) with diffuse-type ISR. Six patients (40%) under-went repeated PCI, seven (46.7%) underwent bypass surgery, and 2 (13.3%) were treated medically. During long-term follow-up (ranging from 12 - 26 months), there were no deaths, 3 (0.8%) MI, and 13 (3.5%) repeated target-lesion revascularization (PCI or CABG) cases. The incidence of major adverse cardiac event was 5.3% in the medical group, 10.1% in the repeated PCI group, and 21.4% in the bypass surgery group. Multivariate analysis showed that the occurrence of DES-ISR did not affect the risk of death or MI. Conclusions: The incidence of ISR was 4% after long DES stenting for coronary arteries. The long-term clinical prognosis of patients with long DES-ISR associated with coronary artery stenting might be benign, if the patient has optimal treatment.

LOW-DOSE RADIOACTIVE ENDOVASCULAR STENTS PREVENT NEOINTIMAL HYPERPLASIA IN RABBITS RESTENOSIS MODEL

Objective To evaluate the effects of low-dose radioactive stents on the prevention of restenosis in rabbit model. Methods The stents were bombarded with suitable charged particles of adapted energy in the cyclotron to create a proper mixture of the radionuclides 59 Fe, 60 Co, 58 Co, 51 Cr, and 54 Mn. The radioactive stents were implanted in the iliac arteries of rabbits. The effects of radioactive stents on prevention of restenosis were assessed by angiography, histomorphometry and immunocytochemistry. Results All the iliac arteries that had been implanted with radioactive stents were patent on angiography and had no radiation complication during the 1～2 months of follow-up. There was a significant reduction in neointimal area (0.37±0.14mm 2 vs. 0.81±0.10mm 2, P<0.01), percent area stenosis (6.7±2.9% vs. 13.2±1.4%, P<0.01) and PCNA immunoreactive rate (2.00±1.58% vs. 10.88±6.98%, P<0.05) in the radioactive stent group compared with the control stent group. Conclusion Radioactive stents with an active of 0.91～1.65 μCi could inhibit SMC proliferation and neointimal hyperplasia in animal restenosis model. The low-dose radioactive stents are safe and feasible for prevention of restenosis.

Two-Stent Strategy for Bifurcation Lesions in Percutaneous Transluminal Coronary Angioplasty: Real-World Evidence

Background: Bifurcation lesions pose a high risk for adverse events after percutaneous coronary intervention (PCI). Evidence supporting the benefits of the two-stent strategy (2SS) for treating coronary bifurcation lesions in India is limited. This study aimed to evaluate the clinical outcomes of various 2SSs for percutaneous transluminal coronary angioplasty for bifurcation lesions in India. Materials and Methods: This retrospective, observational, multicentric, real-world study included 64 patients over 8 years. Data on demographics, medical history, PCI procedures, and outcomes were recorded. Descriptive statistics were computed using the SPSS software. Results: Patients (n = 64) had an average age of 65.3 ± 11.1 years, with 78.1% males. Acute coronary syndrome was reported in 18.8%, chronic stable angina in 40.6%, and unstable angina in 34.4% of participants. Two-vessel disease was observed in 98.4% of patients, and 99.4% had true bifurcation lesions. The commonly involved vessels were the left anterior descending artery (50%), left circumflex coronary artery (34.4%), and first diagonal artery (43.8%). Mean percent diameter stenosis was 87.2% ± 10.1%. The mean number of stents used was 2.00 ± 0.34. The 2SS techniques included the T and small protrusion (TAP) (39.1%), double kissing (DK) crush (18.8%), and the culotte techniques (14.1%). Procedural and angiographic success rate was 92.18%. Major adverse cardiovascular events at 1-year follow-up occurred in 7.8% of cases. Conclusion: The 2SS for bifurcation lesions showed favorable in-hospital and follow-up outcomes. Findings can serve as a resource for bifurcation angioplasty in India. Larger real-world studies with robust methodology are needed to validate these results.

Local drug-delivery balloon for proliferative occlusive in-stent restenosis after drug-eluting stent

药涂的汽球为 in-stent 狭窄作为 drug-eluting stents 的一种选择被开发了，但是在如此的背景的药注入汽球的表演以前没被描述。我们在场在与药注入汽球的一种新类型对待的药 eluting stent 培植以后的特别地好攻击的 in-stent 狭窄的一个盒子发展了以便克服不可能为几膨胀使常规药涂的汽球膨胀。

Finite Element Simulation of In-Stent Restenosis with Tissue Growth Model

In this study, a finite element simulation of in-stent restenosis (ISR) is conducted to simulate the deployment and expansion of a stent in an occluded artery with a contact model and a mechanics-based growth model. A tissue growth model based on the multiplicative decomposition of deformation is applied to investigate the growth of the plaque and artery wall upon the stent’s implantation. Due to the high stresses at the contact points between the stent struts and the tissue, further tissue injury or restenosis is observed. The simulation results show that after the stent deployment, the von Mises stress is significantly larger in the plaque compared to the artery wall, especially in the region that is in contact with the stent. However, the growth of the plaque and artery tends to even out the stress concentration over time. The tissue growth is found to be more significant near the inner wall than the outer layer. A 0.77 mm restenosis is predicted, which agrees with published clinical observations. The features of the artery growth are carefully analyzed, and the underlying mechanism is discussed. This study is the first attempt to apply finite element analysis to artery restenosis, which establishes a framework for predicting ISR’s occurrence and severity. The results also provide insights into understanding the underlying mechanism of in-stent restenosis.

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.