基于Y-shaped路网的早高峰拼车定价策略

针对交通资源配置有限导致的早高峰通勤拥堵问题,借鉴共享经济理论,引入拼车出行概念,充分考虑通勤者出行方式和Y-shaped路网特点,建立了基于通勤者出行效益的拼车定价模型.模型结合费用补偿机制,讨论了以平台利润最大化和系统负效用最小化为目标的拼车定价策略,并给出了定价策略有效的阈值条件.研究结果表明,当通勤者都参与到拼车服务中时,拼车平台利润和交通系统负效用在其相应拼车定价策略下均能达到最优值,并且以交通系统负效用最小化为目标的拼车定价策略能消除Y-shaped路网中瓶颈处的交通拥堵.

Gastrotracheal fistula:Treatment with a covered self-expanding Y-shaped metallic stent

A 67-year-old man had a sev-ere cough and pulmonary infection for 1 wk before seeking evaluation at our hospital.He had undergone esophagectomy with gastric pull-up and radiotherapy for esophageal cancer 3 years previously.After admission to our hospital,gastroscopy and bronchoscopy revealed a fistulous communication between the posterior tracheal wallnear the carina and the upper residual stomach.We measured the diameter of the trachea and bronchus and determined the site and size of the fistula using multislice computed tomography and gastroscopy.A covered self-expanding Y-shaped metallic stent was implanted into the trachea and bronchus.Subsequently,the fistula was closed completely.The patient tolerated the stent well and had good palliation of his symptoms.

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.

Endoscopic-ultrasound-guided biliary drainage with placement of electrocautery-enhanced lumen-apposing metal stent for palliation of malignant biliary obstruction:Updated meta-analysis

BACKGROUND Endoscopic ultrasound-guided biliary drainage using electrocautery-enhanced(ECE)delivery of lumen-apposing metal stent(LAMS)is gradually being re-cognized as a viable palliative technique for malignant biliary obstruction after endoscopic retrograde cholangiopancreatography(ERCP)failure.However,most of the studies that have assessed its efficacy and safety were small and hetero-geneous.Prior meta-analyses of six or fewer studies that were published 2 years ago were therefore underpowered to yield convincing evidence.AIM To update the efficacy and safety of ECE-LAMS for treatment of biliary ob-struction after ERCP failure.METHODS We searched PubMed,EMBASE,and Scopus databases from the inception of the ECE technique to May 13,2022.Primary outcome measure was pooled technical success rate,and secondary outcomes were pooled rates of clinical success,re-intervention,and adverse events.Meta-analysis was performed using a random-effects model following Freeman-Tukey double-arcsine transformation in R soft-ware(version 4.1.3).RESULTS Fourteen eligible studies involving 620 participants were ultimately included.The pooled rate of technical success was 96.7%,and clinical success was 91.0%.Adverse events were reported in 17.5%of patients.Overall reinter-vention rate was 7.3%.Subgroup analyses showed results were generally consistent.CONCLUSION ECE-LAMS has favorable success with acceptable adverse events in relieving biliary obstruction when ERCP is impossible.The consistency of results across most subgroups suggested that this is a generalizable approach.

Numerical Study of the Biomechanical Behavior of a 3D Printed Polymer Esophageal Stent in the Esophagus by BP Neural Network Algorithm

Esophageal disease is a common disorder of the digestive system that can severely affect the quality of life andprognosis of patients. Esophageal stenting is an effective treatment that has been widely used in clinical practice.However, esophageal stents of different types and parameters have varying adaptability and effectiveness forpatients, and they need to be individually selected according to the patient’s specific situation. The purposeof this study was to provide a reference for clinical doctors to choose suitable esophageal stents. We used 3Dprinting technology to fabricate esophageal stents with different ratios of thermoplastic polyurethane (TPU)/(Poly-ε-caprolactone) PCL polymer, and established an artificial neural network model that could predict the radial forceof esophageal stents based on the content of TPU, PCL and print parameter. We selected three optimal ratios formechanical performance tests and evaluated the biomechanical effects of different ratios of stents on esophagealimplantation, swallowing, and stent migration processes through finite element numerical simulation and in vitrosimulation tests. The results showed that different ratios of polymer stents had different mechanical properties,affecting the effectiveness of stent expansion treatment and the possibility of postoperative complications of stentimplantation.

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.

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.

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.

Acute Stent Thrombosis: A Case at the Montlucon Hospital Center

Background and objective: Coronary angioplasty is one of the techniques introduced in 1976 by Andreas Grüntzig in Zurich. It is a revolutionary procedure that allows coronary circulation to be restored by inserting a stent. This new technique has considerably evolved over time, but sometimes has limitations, such as the development of neo-pathologies like stent thrombosis. The aim of our case report is to highlight one of the limitations of coronary angioplasty, although rare, and to encourage greater clinical and electrical monitoring after each procedure. Case report: We report the case of a patient who presented with early stent thrombosis barely an hour after placement of a pharmacoactive stent. Chest pain reported by the patient after the procedure and electrical changes prompted an urgent repeat procedure. Aetiologies of stent thrombosis are multifactorial, including patient-, procedure- and stent-dependent factors. Conclusion: Although rare, there is a risk of stent thrombosis after coronary angioplasty. Careful monitoring and rigorous follow-up of patients after coronary angioplasty are therefore required, as the prognosis for stent thrombosis is fairly poor.

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.

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.

Self-expanding metal stent for relieving the stricture after endoscopic injection for esophageal varices

BACKGROUND Esophageal stricture is one of the complications after esophageal varices sclero-therapy injection(ESI),and the incidence rate is between 2%-10%.AIM To explore the efficacy of self-expanding metal stent(SEMS)for the stricture after endoscopic injection with cyanoacrylate(CYA)and sclerotherapy for esophageal varices.METHODS We retrospectively analyzed the efficacy of SEMS to improve the stricture after endoscopic injection with CYA and sclerotherapy for esophageal varices in 4 patients from February 2023 to June 2023.RESULTS The strictures were improved in four patients after stenting.The stent was removed after two weeks because of chest pain with embedding into esophageal mucosa in one patient.The stent was removed after one month,however,the stent was reinserted because of the strictures happening again in two patients.The stent was removed after three months,however,the stent was reinserted because of the strictures happening again in one patient.The stent embedded into esophageal mucosa in three patients.There were 3 patients suffered reflux esophagitis,and the acid reflux was relieved by taking hydrotalcite.There was no other complication of esophageal perforation,bleeding from varices or infection.CONCLUSION SEMS may relieve the stricture which happened after endoscopic injection with CYA and sclerotherapy for esophageal varices.However,when we should remove the stent still needs to be explored.

Baerveldt glaucoma implant with Supramid© ripcord stent in neovascular glaucoma: a case series

AIM:To report the outcome of Baerveldt glaucoma implant(BGI)with Supramid©ripcord use in neovascular glaucoma(NVG).METHODS:We retrospectively evaluated the surgical outcome of the BGI with Supramid©3/0 ripcord stent in patients with NVG.No tube ligation or venting slits were performed.Supramid was removed after 3mo if the target intraocular pressure(IOP)was not achieved.Surgical success was defined as IOP≤21 mm Hg with(qualified success)or without IOP-lowering medications(complete success).RESULTS:Twenty-six eyes from 24 patients were included in the study.The median duration of follow-up was 4[interquartile range(IQR)=1-5]y,ranging from 0.5 to 5y.IOP decreased by a mean of 24.2 mm Hg(59.7%);from a mean of 40.5±12.6 mm Hg at baseline to 16.3±11.9 mm Hg,P≤0.001.The number of glaucoma medications reduced from a median of 5(IQR=5-6)to 1(IQR=0-2,P≤0.001)at the final follow-up.Overall success rates were 88.0%at 1y,34.8%at 3y,66.7%at 4y,and 50%at 5y.Hypertensive phase(HP)in the first 3mo occurred in 15/26 eyes(57.7%)with a mean IOP of 31.1 mm Hg.CONCLUSION:BGI with Supramid©ripcord stent gives close to 90%of the overall survival rate at the final follow-up without significant early hypotony.However,early HP is still a challenge.

Special stent for draining the abdominal abscess respectively from colon and duodenum:A case report

BACKGROUND Postoperative abdominal infections are an important and heterogeneous health challenge.Many samll abdominal abscesses are resolved with antibiotics,but larger or symptomatic abscesses may require procedural management.CASE SUMMARY A 65-year-old male patient who suffered operation for the left hepatocellular carcinoma eight months ago,came to our hospital with recurrent abdominal pain,vomit,and fever for one month.Abdominal computed tomography showed that a big low-density dumbbell-shaped mass among the liver and intestine.Colonoscopy showed a submucosal mass with a fistula at colon of liver region.Gastroscopy showed a big rupture on the submucosal mass at the descending duodenum and a fistula at the duodenal bulb.Under colonoscopy,the brown liquid and pus were drained from the mass with“special stent device”.Under gastroscopy,we closed the rupture of the mass with a loop and six clips for purse stitching at the descending duodenum,and the same method as colonoscopy was used to drain the brown liquid and pus from the mass.The symptom of abdominal pain,vomit and fever were relieved after the treatment.CONCLUSION The special stent device could be effectively for draining the abdominal abscess respectively from colon and duodenum.

Percutaneous nephrostomy versus ureteral stent in hydronephrosis secondary to obstructive urolithiasis:A systematic review and meta-analysis

Objective: To assess if there is a preferable intervention between retrograde ureteral stent (RUS) and percutaneous nephrostomy (PCN) tube, in cases of upper urinary tract stone obstruction with complications requiring urgent drainage, by evaluating outcomes regarding urinary symptoms, quality of life (QoL), spontaneous stone passage, and length of hospital stays, since there is no literature stating the superiority of one modality over the other.Methods: We searched MEDLINE and other sources for relevant articles in June 2019 without any date restrictions or filters applied. The selection was done first by the title and abstract screening and then by full-text assessment for eligibility. Only randomized controlled trials or cohort studies in patients with hydronephrosis secondary to obstructive urolithiasis that presented comparative data between PCN and RUS placement concerning at least one of the defined outcome measures were included. Lastly, MEDLINE database and PubMed platform were screened again using the same terms, from June 2019 until November 2022.Results: Of 556 initial articles, seven were included in this review. Most works were considered of moderate-to-high quality. Three studies regarding QoL showed a tendency against stenting, even though only one demonstrated statistically significant negative impact on overall health state. Two works reported significantly more post-intervention urinary symptoms in stenting patients. One article found that PCN is a significant predictor of spontaneous stone passage, when adjusted for stone size and location. Findings on length of hospital stays were not consistent among articles.Conclusion: PCN appears to be the intervention better tolerated, with less impact on the patient’s perceived QoL and less post-operative urinary symptoms, in comparison with RUS. Nevertheless, further studies with larger samples and a randomized controlled design are suggested.

Vertebral Artery Stenting for Acute Multiple Cerebral Infarctions Caused by Vertebral Artery Dissection After Massage:A Case Report

Vertebral artery dissection is a rare pathology that can cause ischemic stroke in young people.Cervical massage,especially improper pulling manipulation,is a cause of vertebral artery dissection.We present a case of 32-year old woman who developed acute multiple posterior circulation ischemic cerebral infarctions as a result of left vertebral artery V4 segment dissection after receiving neck massage.She underwent emergency vertebral artery stent implantation at the site of the dissection.Symptoms were relieved the day after treatment.The patient recovered without adverse complications or endovascular restenosis in the following year.

Bioresorbable stent unloading during percutaneous coronary intervention:Early detection and management

In this letter,we comment on a recent case report by Sun et al in the World Journal of Cardiology.The report describes the successful management of a rare complication:The unloading or detachment of a bioresorbable stent(BRS)during percutaneous coronary intervention(PCI)in a male patient.The unloading of BRS was detected via angiography and intravascular ultrasound(IVUS)imaging of the left coronary artery and left anterior descending artery.Although this case is interesting,the authors’report lacked crucial details.Specifically,insufficient information about the type of BRS used,potential causes of BRS unloading,or whether optical coherence tomography(OCT)imaging for coronary arteries was performed before,during,or after PCI.The OCT imaging of coronary arteries before PCI can potentially prevent BRS unloading due to its higher resolution compared to IVUS.In addition,despite detecting myocardial bridging during the PCI,the authors did not provide any details regarding this variation.Here we discuss the various types of BRS,the importance of OCT in PCI,and the clinical relevance of myocardial bridging.

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.

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.

Research on the Microstructure Construction Technology of Fully Degraded Polymer Vascular Stent Based on Electric Field Driven 3D Printing

The so-called fourth-generation biodegradable vascular stent has become a research hotspot in thefield of bioengineering because of its good degradation ability and drug-loading characteristics.However,the preparationof polymer-degraded vascular stents is affected by known problem such as poor processflexibility,low formingaccuracy,large diameter wall thickness,limited complex pore structure,weak mechanical properties of radial support and high process cost.In this study,a deposition technique based on a high-voltage electric-field-driven continuous rotating jet is proposed to fabricate fully degraded polymer vascular stents.The experimental results showthat,due to the rotation of the deposition axis,the deposition direction of PCL(polycaprolactone)micro-jet isalways tangent to the surface of the deposition axis.The direction of the viscous drag force is also consistent withthe deposition direction of the jet.It is shown that by setting different rotation speeds of deposition axisωandlinear motion speeds of the nozzle V,the direction of rotation,pitch and angle of the individual printed spiralcurve can be precisely tuned.In the process of multiple spiral curves matching the deposition forming thin walltube mesh,the mesh shape and size of the thin wall tube can be accurately controlled by changing the number ofmatching spiral curves and the size of the matching position bias distance.Finally,the characteristics of a PCLtubular stent sample(with uniform-size microfibers and mesh shape),fabricated under the appropriate processparameters are described in detail.