Polish Society of Biomechanics Morecki&Fidelus Award Winner: Comparison of two polymers PDO and PLLA/PCL in application of urological stent for the treatment of male urethral stenosis.

Purpose: The primary objective of the conducted research was to develop an urological stent design for the treatment of male ure-thral stenosis. Given the variable loading conditions inside the urethra, the proposed stent should maintain normal tissue kinetics and obstruct the narrowed lumen. The suitable selection for the stent material significantly influences the regeneration and proper remodeling of the urethral tissues. Methods: In this work, the mechanical characteristics of some polymer materials were studied, including: polydi-oxanone (PDO) and poly(L-lactide) (PLLA)/polycaprolactone (PCL) composite. The obtained mechanical properties for static tensile testing of the materials, allowed the determination of such parameters as Young's modulus (E), tensile strength (R m) and yield strength (R e). Subsequently, the design of a urological stent was developed, for which a numerical analysis was carried out to check the behaviour of the stent during varying loads prevailing in the urethra. Result: The research indicated that PDO has better mechanical properties than the proposed PLLA/PCL composite. The numerical analysis results suggested that the developed stent design can be successfully used in the treatment of male urethral stenosis. The obtained stress and strain distributions in the numerical analysis confirm that the PDO material can be used as a material for an urological stent. Conclusions: The biodegradable polymers can be successfully used in urology. Their advantages over solid materials are their physicochemical properties, the ability to manipulate the rate and time of degradation and the easy availability of materials and manufacturing technology.

Impact of lower limb movements on iliac vein stenting in iliac vein compression syndrome patients: insights from computational modeling.

Purpose: Iliac vein stenting is the primary treatment for patients with iliac vein compression syndrome (IVCS). However, post-stent placement, patients often experience in-stent restenosis and thrombosis. Despite this, the role of lower limb movements in the functioning of stents and veins in IVCS patients remains unclear. This study aimed to address this knowledge gap by developing a computational model using medical imaging techniques to simulate IVCS after stent placement. Methods: This research used a patient-specific model to analyze the effects of lower extremity exercises on hemodynamics post-stent placement. We conducted a comprehensive analysis to evaluate the impact of specific lower limb movements, including hip flexion, ankle movement and pneumatic compression on the hemo-dynamic characteristics within the treated vein. The analysis assessed parameters such as wall shear stress (WSS), oscillatory shear index (OSI), and residence time (RRT). Results: The results demonstrated that hip flexion significantly disrupts blood flow dynamics at the iliac vein bifurcation after stenting. Bilateral and left hip flexion were associated with pronounced regions of low WSS and high OSI at the iliac-vena junction and the stent segment. Additionally, active ankle exercise (AAE) and intermittent pump compression (IPC) therapy were found to enhance the occurrence of low WSS regions along the venous wall, potentially reducing the risk of thrombosis post-stent placement. Consequently, both active joint movements (hip and ankle) and passive movements have the potential to influence the local blood flow environment within the iliac vein after stenting. Conclusions: The exploration of the impact of lower limb movements on hemodynamics provides valuable insights for mitigating adverse effects associated with lower limb movements post iliac-stenting. Bilateral and left hip flexions negatively impacted blood flow, increasing thrombosis risk. However, active ankle exercise and intermittent pump compression therapies effectively improve the patency.

[Therapeutic endoscopic ultrasound: an innovative technique, revolutionizing our practice]. / Échoendoscopie thérapeutique : une technique innovante qui révolutionne la pratique.

The field of digestive endoscopy evolves continuously, offering -patients significant advances both in the diagnostic and therapeutic fields. The introduction of lumen--apposing metal stents has enabled innovation in several endoscopic techniques, including endoscopic ultrasound--guided gallbladder drainage, choledochoduodeno-stomy, gastroenteroanastomosis, and transgastric endoscopic retrograde cholangiopancreatography (EDGE). Compared to traditional treatment methods, these procedures have shown excellent success rates, coupled with a reduced risk of postoperative morbidity and lower costs.

L'endoscopie digestive connaît une évolution continue, offrant ainsi aux patients des avancées significatives, tant d'un point de vue diagnostique que thérapeutique. L'apparition des stents ­métalliques d'apposition luminale a permis le développement de plusieurs techniques endoscopiques innovantes telles que le drainage de la vésicule biliaire, la cholédocoduodénostomie, la gastro-­entéro-­anastomose et la cholangiopancréatographie ­rétrograde endoscopique transgastrique guidée par échoendo­scopie (EDGE). Comparées aux méthodes de traitements ­traditionnelles, ces procédures ont montré d'excellents taux de réussite, un risque réduit de morbidité postopératoire et des coûts moindres.

Non-circulatory arrest aortic arch replacement.

The definitive management of combined aortic arch and descending aortic pathologies such as aneurysms and dissections is either a single or staged operation associated with high morbidity and mortality. Stroke, kidney dysfunction, coagulopathy and high blood transfusion requirements are all affiliated with hypothermic circulatory arrest and prolonged cardiopulmonary bypass times. Considering the perilous nature of these operations, the authors describe a step-by-step zone 2 arch replacement as a staged frozen elephant trunk procedure, which provides an adequate landing zone for a later-placed endovascular stent yet maintains a short cardiopulmonary bypass time and no circulatory arrest.

"One-stop" interventional therapy for quadricuspid aortic valve combined with severe coronary artery disease: a case report.

Congenital Quadricuspid Aortic Valve (QAV) malformation is a relatively rare cardiac valve malformation, especially with abnormal coronary opening and severe stenosis of Coronary Artery Disease (CAD). The patient underwent "one-stop" interventional treatment with transcatheter aortic valve replacement and percutaneous coronary stent implantation. Follow up for 12-month with good outcomes.

Fenestrated and Branched Endovascular Aortic Aneurysm Repair for Treating Juxtarenal Aneurysms: An Update.

Fenestrated and branched endovascular aortic aneurysm repair (f-EVAR, b-EVAR, respectively) are technically challenging procedures that have evolved over the last decade for complex aortic aneurysms. They are alternatives to surgical repair for suprarenal and juxtarenal aortic aneurysms. A Pubmed database was reviewed by searching keywords related to f-EVAR, b-EVAR, and juxta renal abdominal aortic aneurysm (AAA) from the last five years to see current indications, contemporary techniques, and results of these techniques for juxtarenal aneurysms. Over the years, f-EVAR and b-EVAR have improved, with high technical success (>95%) and mortality rates of 1-5% for pararenal and 5-10% for thoracoabdominal aortic aneurysms. Key Words: Fenestrated-branched endovascular repair, Fenestrated EVAR, Branched EVAR, Juxtarenal aortic aneurysm.

Normal Saline Versus Hypertonic Saline for Airway STENT Maintenance: SALTY STENT Study.

BACKGROUND: Mucus plugging is a common complication of airway stenting. There is no data or guidance on the best airway hygiene regimen and consequently wide practice variation exists. METHODS: This single-center, nonblinded, randomized, pilot study aims to evaluate the effectiveness and safety of nebulized 3% saline (3%S) versus normal saline (NS) in reducing the incidence of mucus plugging in adult patients that undergo central airway stent placement. Patients were enrolled immediately after stent placement and randomized to nebulized 3%S or NS (3 mL) 3 times a day. Patients were scheduled for surveillance bronchoscopy in 4 to 6 weeks. Unscheduled bronchoscopies due to symptomatic mucus plugging were recorded. RESULTS: From December 2022 to March 2024, 37 patients were screened, and 35 were enrolled. Four in the 3%S and 8 in the NS group did not undergo a surveillance bronchoscopy and were excluded from the final analysis. During surveillance bronchoscopy for the 3%S (n=13) and NS (n=10) groups, obstructive mucus plugging was noted in 7.7% versus 40%, granulation requiring intervention in 7.7% versus 10%, and >25% circumferential biofilm in 0% versus 30%, respectively. In the 3%S versus NS groups, 0% versus 20% of patients required an unscheduled bronchoscopy due to mucus plugging. There were no side effects reported with the daily use of 3%S or NS. CONCLUSION: Nebulized 3%S is safe and may be equally or more effective than NS in preventing obstructive mucus plugging in patients who undergo airway stenting. A larger blinded randomized controlled trial is necessary to confirm this finding.

[Structural design of "fitness" and "feasibility" of body-fitted stent and its mechanical analysis].

To address the conflict between the "fitness" and "feasibility" of body-fitted stents, this paper investigates the impact of various smoothing design strategies on the mechanical behaviour and apposition performance of stent. Based on the three-dimensional projection method, the projection region was fitted with the least squares method (fitting orders 1-6 corresponded to models 1-6, respectively) to achieve the effect of smoothing the body-fitted stent. The simulation included the crimping and expansion process of six groups of stents in stenotic vessels with different degrees of plaque calcification. Various metrics were analyzed, including bending stiffness, stent ruggedness, area residual stenosis rate, contact area fraction, and contact volume fraction. The study findings showed that the bending stiffness, stent ruggedness, area residual stenosis rate, contact area fraction and contact volume fraction increased with the fitting order's increase. Model 1 had the smallest contact area fraction and contact volume fraction, 77.63% and 83.49% respectively, in the incompletely calcified plaque environment. In the completely calcified plaque environment, these values were 72.86% and 82.21%, respectively. Additionally, it had the worst "fitness". Models 5 and 6 had similar values for stent ruggedness, with 32.15% and 32.38%, respectively, which indicated the worst "feasibility" for fabrication and implantation. Models 2, 3, and 4 had similar area residual stenosis rates in both plaque environments. In conclusion, it is more reasonable to obtain the body-fitted stent by using 2nd to 4th order fitting with the least squares method to the projected region. Among them, the body-fitted stent obtained by the 2nd order fitting performs better in the completely calcified environment.

The association between stent type and developing angina pectoris following percutaneous coronary intervention.

BACKGROUND: Angina pectoris can occur in up to 40% of patients following percutaneous coronary intervention (PCI). There is limited data assessing whether the type of stent implanted during revascularization can predict post-PCI angina symptoms. METHODS: In this study, data regarding revascularization characteristics including the stent type in patients admitted for PCI was collected. Prospective data including occurrence of angina and the presenting class, new onset ST-segment elevation myocardial infarction (STEMI), and other clinical outcomes were collected at 1, 3, and 6-month follow-up intervals. Univariable and multivariable logistic regression models were used to assess the potential predictors of angina symptoms at 6-month follow-up. RESULTS: A total of 787 patients (64.5% males) undergoing PCI with three stent types (Orsiro, Promus, and Xience) were included in the study. The occurrence of post PCI angina pectoris and new STEMI was similar among the stent types (p > 0.05). A linear association was found between the development of new STEMI (p = 0.018) and stroke (p = 0.003) and the worsening of angina class. The stent type was not a predictor of angina during the follow-up period. Other variables including dyslipidemia (odds ratio (OR) (95% CI), 1.51 (1.08; 2.10)), prior coronary artery disease (CAD) (OR (95% CI), 1.63 (1.02; 2.61)), and previous hospitalization (OR (95% CI), 2.10 (1.22; 3.63)) were independent predictors of angina. CONCLUSIONS: Although the type of stent may not have an association with the post-PCI angina, other predictors such as dyslipidemia and previous CAD and hospitalization may predict recurrence of cardiac angina. The class of angina severity may have a linear association with new-onset STEMI and stroke.

Analysis of Risk Factors for Poor Drainage of Ureteral Stents after Radical Cystectomy with Cutaneous Ureterostomy: A Retrospective Study.

OBJECTIVE: Currently, the factors influencing poor drainage of ureteral stents after radical cystectomy with cutaneous ureterostomy are still unclear. Therefore, the aim of this study was to determine the risk factors for poor drainage of ureteral stents after radical cystectomy with cutaneous ureterostomy and to provide evidence for the prevention of this complication. METHODS: This retrospective study included 86 patients who underwent periodic replacement of ureteral stents following radical cystectomy with cutaneous ureterostomy between October 2017 and March 2024. The general data and related indicators of the patients were collected, the risk factors were identified through univariate and multivariate logistic regression analyses, and corresponding interventions were proposed. RESULTS: Among the 86 patients, 26 had poor drainage of ureteral stents, with an incidence rate of 30.23%, and no serious consequences occurred after timely and effective treatment. Univariate and multivariate logistic regression analyses revealed that body mass index (BMI) (p = 0.003, odds ratio (OR) = 2.909, 95% CI: 1.435-5.898), diabetes mellitus (p = 0.012, OR = 14.073, 95% CI: 1.770-111.889), urinary tract infection (p = 0.004, OR = 16.792, 95% CI: 2.402-117.411), and foreign body blockage (p = 0.048, OR = 5.277, 95% CI: 1.012-27.512) were independent risk factors for poor drainage of ureteral stents. CONCLUSIONS: The incidence of poor drainage of ureteral stents after radical cystectomy with cutaneous ureterostomy is relatively high. Maintenance of a healthy weight, strict management of blood glucose levels, active prevention of urinary tract infections, and timely detection and removal of small foreign bodies that may be present are essential to prevent this complication.

Surgical Palliation for Advanced Pancreas Cancer.

To provide optimal care in pancreatic ductal adenocarcinoma, involvement of palliative medicine and nutritional support is recommended. Advances in endoscopy have resulted in robust options for biliary and gastrointestinal stenting for relief of obstruction. Notwithstanding, surgical hepaticojejunostomy and gastrojejunostomy remain incontrovertible considerations for biliary obstruction and gastric outlet obstruction, respectively. For PDAC-associated pain, opioid therapy continues to be the mainstay. However, refractory pain may be treated with interventional procedures such as celiac or splanchnic nerve blocks or neurolysis. In patients with PDAC, enteral nutrition can be further complicated by exocrine pancreatic insufficiency, which should be treated with oral pancreatic enzyme supplementation.

Mid-term outcomes of different treatments of internal iliac artery in endovascular aneurysm repair.

OBJECTIVE: To evaluate the mid-term outcomes of different treatment strategies for the internal iliac artery (IIA) during EVAR. METHODS: This was a retrospective study. All patients undergoing EVAR, who required treatment of at least one side of IIA from January 2013 to July 2022 in a single center, were included. According to the different treatment strategies for IIA, the patients were divided into UP (unilateral preservation), BP (bilateral preservation) and BE (bilateral embolization) groups. The primary outcomes included buttock claudication, bowel ischemia and iliac-related reintervention. Then patients who underwent IIA reconstruction were divided into IPG (iliac parallel stent graft) and IBG (iliac branch stent graft) groups according to the reconstruction technique. The primary outcomes included endoleak, iliac branch occlusion and iliac-related reintervention. RESULTS: A total of 237 patients were included, including 167 in the UP group, 9 in the BP group and 61 in the BE group. The mean follow-up time was 39.0 ± 27.7, 50.0 ± 22.1 and 25.8 ± 18.9 months in UP, BP and BE groups, respectively. Thirty cases (12.7%) of buttock claudication occurred, and it was significantly higher in the BE group than the UP group (26.2% vs. 7.8%, p < 0.001). There were no significant differences in the other follow-up outcomes among three groups. The K-M analysis indicated that the patients in the BE group had a lower survival rate than those in the other two groups (p = 0.024). 24 patients underwent IIA reconstruction, including 8 in the IPG group and 16 in the IBG group. The endoleak in the IBG group was significantly lower than that in the IPG group (0% vs. 25.0%, p = 0.041). The iliac-related reintervention, iliac occlusion and mortality were similar between the two groups. CONCLUSION: Overall it is beneficial for patients to preserve at least one side of IIA during EVAR as much as possible. Compared with IPG, IBG might be more applicable for IIA reconstruction.

Three-Year Outcomes, Risk Factors for Restenosis After Stenting for DVT Combined with Iliac Vein Compression Syndrome.

This study aimed to evaluate the safety and efficacy of pharmacomechanical catheter-directed thrombolysis (PCDT) and stenting for treating acute iliofemoral deep venous thrombosis (DVT) combined with iliac vein compression syndrome (IVCS), and to identify the predictors of stent restenosis. Patients with acute proximal DVT combined with IVCS underwent PCDT and stenting from January 2017 to December 2022 were enrolled. Primary and secondary patency were assessed by duplex ultrasound (DUS). The morbidity of postthrombotic syndrome (PTS) was assessed by the Villalta score. Risk factors for stent restenosis were assessed using univariate and multivariate Cox regression models. Total of 254 patients were included. The mean follow-up time was 36.06 ± 17.66 months. The primary patency rates at 1 year, 3 years, and 5 years were 92.5%±1.7%, 85.4%±2.4%, and 82.4%±2.9%, respectively. The incidence of stent restenosis was 14.2%. Discontinuation of anticoagulants within one year [hazard ratio (HR) = 5.03; P = .048] was the factor associated with acute in-stent thrombosis. Previous DVT history (HR =2.29; P = .037) and stent placement across the inguinal ligament (HR =6.70; P < .001) were identified as independent risk factors significantly associated with stent restenosis. The overall PTS rate was 19.3%. PCDT with stenting is safe and effective for patients with iliofemoral DVT secondary to IVCS, leading to low rates of PTS. Previous DVT history and stents placed across the inguinal ligament may be predictors of stent restenosis. Furthermore, stent restenosis typically occurs within one year and is mainly caused by acute thrombosis due to discontinuation of anticoagulants.

Comparison of LVIS and Enterprise stent-assisted coiling embolization for ruptured intracranial aneurysms: a propensity score-matched cohort study.

The role of a low-profile visualized intraluminal support stent (LVIS) and Enterprise in the treatment of unruptured intracranial aneurysms is well established. Although previous studies have investigated one single type of stent for the treatment of ruptured intracranial aneurysms (RIA), the safety and efficacy between the two types of stents has not been fully explored. Herein we conducted a study to compare the outcomes of the two stents for treatment of RIA. This is a prospective registry database of aneurysmal subarachnoid hemorrhage (aSAH) patients admitted to a single institution between 2018 and 2021. We collected patient baseline information, secondary complications, follow-up angiographic data, long-term prognostic outcomes, and conducted propensity score matching (PSM) analysis with 1:1 ratio and a multivariable logistic regression to compare the outcomes of the two types of stents. A total of 231 patients with RIAs were included in this study, with 108 treated using the LVIS device and 123 treated using the Enterprise device. Before PSM analysis, only the incidence of poor prognosis after 12 months was higher in the Enterprise group comparing to the LVIS group (20% vs. 10%, P = 0.049). After PSM analysis, there was a higher occurrence of delayed cerebral ischemia (DCI) in the Enterprise group compared to the LVIS group (odds ratio [OR] 3.95, 95% confidence interval [CI] [1.20-13.01], P = 0.024). However, no significant difference in prognosis was observed after PSM adjustment. Furthermore, subgroup analysis revealed that patients with female (P = 0.019), hypertension (P = 0.048), and anterior circulation aneurysms (P = 0.019) receiving the Enterprise device had a higher risk of DCI. The overall efficacy of LVIS and Enterprise in the treatment of RIA is comparable, while the incidence of DCI in the LVIS group is lower than that in the Enterprise group after PSM analysis. Registration number: NCT05738083 ( https://clinicaltrials.gov/ ).

Healthcare-related carbon footprinting-lower impact of a coronary stenting compared to a coronary surgery pathway.

Healthcare is a major generator of greenhouse gases, so consideration of this contribution to climate change needs to be quantified in ways that can inform models of care. Given the availability of activity-based financial data, environmentally-extended input-output (EEIO) analysis can be employed to calculate systemic carbon footprints for healthcare activities, allowing comparison of different patient care pathways. We thus quantified and compared the carbon footprint of two common care pathways for patients with stable coronary artery disease, with similar clinical outcomes: coronary stenting and coronary artery bypass surgery (CABG). Healthcare cost data for these two pathways were disaggregated and the carbon footprint associated with this expenditure was calculated by connecting the flow of money within the economy to the greenhouse gases emitted to support the full range of associated activities. The systemic carbon footprint associated with an average stable patient CABG pathway, at a large tertiary referral hospital in Sydney, Australia in 2021-22, was 11.5 tonnes CO2-e, 4.9 times greater than the 2.4 tonnes CO2-e footprint of an average comparable stenting pathway. These data suggest that a stenting pathway for stable coronary disease should be preferred on environmental grounds and introduces EEIO analysis as a practical tool to assist in health-care related carbon footprinting.

Maglev-fabricated long and biodegradable stent for interventional treatment of peripheral vessels.

While chronic limb-threatening ischemia is a serious peripheral artery disease, the lack of an appropriate stent significantly limits the potential of interventional treatment. In spite of much progress in coronary stents, little is towards peripheral stents, which are expected to be both long and biodegradable and thus require a breakthrough in core techniques. Herein, we develop a long and biodegradable stent with a length of up to 118 mm based on a metal-polymer composite material. To achieve a well-prepared homogeneous coating on a long stent during ultrasonic spraying, a magnetic levitation is employed. In vivo degradation of the stent is investigated in rabbit abdominal aorta/iliac arteries, and its preclinical safety is evaluated in canine infrapopliteal arteries. First-in-man implantation of the stent is carried out in the below-the-knee artery. The 13 months' follow-ups demonstrate the feasibility of the long and biodegradable stent in clinical applications.