Stent migration is one of the common complications following transcatheter valve implantation. This study aims to design a "drum-shaped" balloon-expandable aortic valve stent to address this issue and conduct a mechanical analysis. The implantation process of the stent was evaluated using a method that combines numerical simulation and in vitro experiments. Furthermore, the fatigue process of the stent under pulsatile cyclic loading was simulated, and its fatigue performance was assessed using a Goodman diagram. The process of the stent migrating toward the left ventricular side was simulated, and the force-displacement curve of the stent was extracted to evaluate its anti- migration performance. The results showed that all five stent models could be crimped into a 14F sheath and enabled uniform expansion of the native valve leaflets. The stress in each stent was below the ultimate stress, so no fatigue fracture occurred. As the cell height ratio decreased, the contact area fraction between the stent and the aortic root gradually decreased. However, the mean contact force and the maximum anti-migration force first decreased and then increased. Specifically, model S5 had the smallest contact area fraction but the largest mean contact force and maximum anti-migration force, reaching approximately 0.16 MPa and 10.73 N, respectively. The designed stent achieves a "drum-shaped" change after expansion and has good anti-migration performance.
Stents ; Prosthesis Design ; Heart Valve Prosthesis ; Humans ; Aortic Valve/surgery* ; Stress, Mechanical ; Transcatheter Aortic Valve Replacement/instrumentation*

OBJECTIVE: To compare clinical effects of external fixation and minimally invasive percutaneous plate osteosynthesis (MIPPO) after external fixation in treating open fractures of tibial shaft. METHODS: From January 2020 to June 2022, 151 patients with open fracture of tibial shaft treated with external fixation stenting were divided into external fixation group and combined group according to different surgical methods. There were 81 patients in external fixation group, including 48 males and 33 females, aged from 21 to 68 years old with an average of (42.58±7.44) years old;according to Gustilo classification, 49 patients with typeⅡ, 32 patients with type ⅢA;the time from injury to treatment ranged from 2.5 to 10 h with an average of (4.25±0.74) h;external fixed stenting was performed. There were 70 patients in combined group, including 42 males and 28 females, aged from 20 to 69 years old with an average of (41.39±7.02) years old;35 patients with type Ⅱ and 35 patients with type ⅢA according to Gustilo classification;the time from injury to treatment ranged from 3 to 9 h with an average of (4.31±0.85) h;MIPPO treatment was performed after external fixed stenting. The time of callus formation, fracture healing and complications were compared between two groups. Rasmussen score and Hospital for Special Surgery (HSS) score were used to evaluate functional recovery of knee joint at 6 months after operation. RESULTS: Both groups were followed up for 6 to 13 months with an average of (10.17±2.33) months. The time of callus formation and fracture healing were (13.98±4.02) d and (70.26±12.15) d in combined group, and (18.56±4.37) d and (79.87±15.41) d in external fixation group, respectively. Combined group was better than external fixation group in the time of callus formation and fracture healing (P<0.05). At six months after operation, Rasmussen and HSS scores in combined group were (26.79±3.11) and (83.36±9.44), which were higher than those in external fixation group (24.51±4.63) and (79.63±8.46) (P<0.05). In external fixation group, there were 2 patients with incision infection, 2 patients with nail tract infection, 1 patient with stent loosening, fracture displacement, delayed union and malunion, and 1 patient with biocompatibility reaction in combined group, with statistical significance between two groups (P<0.05). CONCLUSION MIPPO could accelerate callus formation and fracture healing, improve knee function, improve clinical effects and reduce complications in patients with open tibial shaft fractures after external and external fixation.
Humans ; Male ; Female ; Middle Aged ; Adult ; Aged ; Tibial Fractures/physiopathology* ; Fracture Fixation, Internal/methods* ; Retrospective Studies ; Bone Plates ; External Fixators ; Fractures, Open/physiopathology* ; Stents ; Young Adult

PURPOSE: Postpancreatectomy hemorrhage (PPH) is a life-threatening complication after pancreatoduodenectomy. Stent-graft implantation is an emerging treatment option for PPH. This study reports the outcome of PPH treated with stent-graft implantation. METHODS: This was a single-center, retrospective study. Between April 2020 and December 2023, 1723 pancreatectomy cases were collected while we screened 12 cases of PPH after pancreatoduodenectomy treated with stent-graft implantation. Patients' medical and radiologic images were retrospectively reviewed. Technical and clinical success, complications, and stent-graft patency were evaluated. Continuous data are reported as means ± standard deviation when normally distributed or as median (Q₁, Q₃) when the data is non-normal distributed. Categorical data are reported as n (%). A p < 0.05 was considered statistically significant. Kaplan-Meier estimates were used for stent patency and patients' survival. RESULTS: Pancreatic fistula was identified in 6 cases (50.0%), and pseudoaneurysm was identified in 3 cases (25.0%), including pancreatic fistula together with pseudoaneurysm in 1 case (8.3%). All pseudoaneurysm or contrast extravasation sites were successfully excluded with patent distal perfusion, thus technical success was achieved in all cases. The overall survival rate at 6 months and 1 year was 91.7% and 78.6%, respectively. One patient had herniation of the small intestine into the thoracic cavity, which caused a broad thoracic and abdominal infection and died during hospitalization. Rebleeding occurred at the gastroduodenal artery stump in 1 case after stent-graft implantation for the splenic artery and was successfully treated with another stent-graft implantation. Two cases of asymptomatic stent-graft occlusion were observed at 24.6 and 26.3 after the operation, respectively. CONCLUSIONS With suitable anatomy, covered stent-graft implantation is an effective and safe treatment option for PPH with various bleeding sites and causes.
Humans ; Pancreaticoduodenectomy/adverse effects* ; Stents ; Male ; Retrospective Studies ; Female ; Middle Aged ; Postoperative Hemorrhage/surgery* ; Aged ; Adult

OBJECTIVES: To investigate the medium- and long-term efficacy of percutaneous mechanical thrombectomy (PMT) combined with stent implantation for treatment of iliac vein stenosis with lower extremity deep venous thrombosis (LEDVT). METHODS: Clinical and follow-up data of 125 patients with iliac vein stenosis and LEDVT who underwent PMT and stent implantation at five hospitals in northern Zhejiang province from January 2017 to June 2021 were collected. The thrombus clearance rate, thrombus recurrence rate, patency rate of iliac vein stents and post-thrombotic syndrome (PTS) occurrence rate were documented, and safety indicators such as bleeding, death, pulmonary embolism, stent fracture and displacement were assessed. RESULTS: Among 125 patients, for clearance of limb thrombosis, there were 8 cases of grade I (6.4%), 10 cases of grade II (8.0%), and 107 cases of grade III (85.6%). Patients were followed up for a median period of 74 months. According to the Villalta score, the recurrence rates of limb thrombosis at 12, 24 and 36 months were 8.48%, 8.93% and 10.91%; the iliac vein patency rates were 91.52%, 91.07%, and 89.09%; and the incidences of PTS were 5.08%, 5.36% and 6.36%, respectively. There were no major adverse events such as death, massive pulmonary embolism or severe hepatic and renal insufficiency, and no readmission intervention events due to stent fracture or other incidence were found. CONCLUSIONS PMT combined with iliac vein stent implantation is effective for patients with iliac vein stenosis complicated by LEDVT with good medium- and long-term efficacy and safety, which is worthy of clinical application.
Humans ; Stents ; Iliac Vein/pathology* ; Venous Thrombosis/surgery* ; Thrombectomy/methods* ; Female ; Male ; Middle Aged ; Aged ; Adult ; Constriction, Pathologic/surgery* ; Treatment Outcome ; Follow-Up Studies

A 72-year-old patient with quadricuspid aortic valve underwent transcatheter aortic valve replacement due to severe valve stenosis accompanied by moderate insufficiency. As initially planned, the right coronary artery was protected during the procedure. However, after the artificial valve was released, the left coronary artery was found to be blocked, so a coronary protection stent was implanted in the left coronary artery ostium under the guidance of intravascular ultrasonography. This case indicates that for patients with a quadricuspid aortic valve undergoing transcatheter aortic valve replacement, in addition to preoperative measurement of the aortic root, attention should also be paid to the coronary artery obstruction caused by the displacement of the artificial valve frame during the procedure.
Aged ; Humans ; Aortic Valve/surgery* ; Aortic Valve Stenosis/surgery* ; Coronary Vessels ; Stents ; Transcatheter Aortic Valve Replacement/methods*

The article introduces the formation process of bacterial infection and encrustation on the surface of ureteral stents, elaborates in detail on six surface modification methods for ureteral stents, namely impregnation, spraying, vapor deposition, chemical grafting, self-assembly, and electrospinning, then analyzes the advantages and limitations of each technique during application. Meanwhile, it introduces three commonly used materials for ureteral stents, namely polymers, metals, and biodegradable materials, and further explains the commonly used surface modification methods corresponding to different materials. Looking ahead, with the continuous strengthening of the multi-technology integration trend and the continuous advancement of new material research and development, it is expected that a more ideal ureteral stent can be developed.
Stents ; Ureter ; Surface Properties ; Humans

Objective:Explore the clinical diagnosis and treatment strategies of recurrent multiple chondritis in children with airway involvement as the main cause. Methods:From June 2021 to May 2023, five children with relapsing polychondritis were admitted to our department, all of whom met the Damiani criteria. Tracheotomy was performed in all five patients. Endoscopy indicated subglottic stenosis, with one case classified as grade Ⅲ and four cases as grade Ⅳ according to the Myer-Cotton classification. Enhanced CT scans of the head and neck showed fixed lumen narrowing and stenosis, including thickening of the soft tissue in the laryngeal cavity and partial absorption of the laryngotracheal cartilage anterior wall. In one patient, tracheal wall thickening and deformation with stenosis and calcification involved the posterior tracheal wall. One patient underwent "laryngeal tracheal reconstruction with hyoid graft, T-tube implantation, and bioabsorbable corticosteroid-eluting stent implantation", while three patients underwent "balloon dilatation, T-tube implantation, and bioabsorbable corticosteroid-eluting stent implantation" . Follow-up was performed every two months after the initial surgery, and three bioabsorbable corticosteroid-eluting stents were placed on the upper left, upper right, and lower T-tube, respectively, during this time. The entire follow-up period was six months. Results:All the 5 cases were in the outpatient department, of which 1 case had been extubation, 3 cases were still in the outpatient follow-up, and the remaining 1 case was still being treated in the rheumatology and immunology department due to poor control of the primary disease. Conclusion:In relapsing polychondritis children with airway involvement, tracheotomy could be used to quickly improve the symptoms of dyspnea in the disease progression. In the stable stage of the disease, the surgical method of 'Balloon dilatation + T-tube implantation + Bioabsorbable corticosteroid-eluting stents implantation' was adopted to reduce the secondary injury caused by surgical trauma as much as possible and improve the survival and quality of life of the children.
Humans ; Polychondritis, Relapsing/surgery* ; Child ; Male ; Female ; Tracheotomy ; Laryngostenosis ; Child, Preschool ; Trachea/surgery* ; Adolescent ; Stents

INTRODUCTION: We aimed to compare the real-world data and our clinical experience with metallic stents (MSs) and conventional polymeric stents (PSs) in the management of both malignant and benign chronic ureteric obstruction (CUO), in terms of clinical outcomes and costs. METHODS: Clinical data from our institution, including outcomes for all ureteric stents inserted for long-term management of CUO from all causes from 2014 to 2017, were retrospectively reviewed and compared between the MS and PS episodes. RESULTS: A total of 247 stents were placed in 63 patients with CUO over the 4-year study period. Of these, 45 stents were MSs. There was no significant difference in all baseline characteristics between the MS and PS groups, except for the aetiology of obstructive cause. Mean indwelling stent duration was significantly greater for MS than for PS (228.6 ± 147.0 vs. 146.1 ± 66.0 days, P < 0.001), thereby leading to lower average number of stent changes per year in the MS group compared to the PS group (1.4 vs. 6.3 times, respectively). Despite the higher unit cost of MS compared to PS, there was no significant mean cost difference overall (cost per dwelling day SGD 7.82 ± SGD 10.44 vs. SGD 8.23 ± SGD 20.50, P = 0.888). CONCLUSION Resonance MS is a better option than PS to manage CUO from malignant and benign causes because its significantly longer indwelling time mitigates the higher unit cost of the stent. It potentially reduces the number of procedures and operations in patients. Thus, it should be considered for all patients with CUO requiring long-term ureteric drainage.
Humans ; Ureteral Obstruction/economics* ; Female ; Male ; Retrospective Studies ; Stents/economics* ; Middle Aged ; Aged ; Treatment Outcome ; Chronic Disease ; Ureter/surgery* ; Metals ; Adult ; Aged, 80 and over

Objective To investigate the association of bare-metal stent （BMS）， drug-coated balloon（DCB）， and plain balloon（PB） with postoperative restenosis in the treatment of vertebral artery origin stenosis （VAOS）. Methods The patients with symptomatic VAOS who underwent revascularization in our center were enrolled and divided into BMS group， DCB group， and PB group according to their treatment modality. The primary outcome was 12-month restenosis rate （≥50% stenosis）， and secondary outcomes included postoperative residual stenosis rate， 3- and 6-month restenosis rates， and 3-month good functional outcome （modified Rankin Scale score ≤1）. The binary logistic regression analysis was used to assess the effect of different treatment modalities on outcome. Results The 12-month restenosis rate was 29.3% in the BMS group， 24.4% in the DCB group， and 42.9% in the PB group， with no significant difference between the three groups（P=0.234）. There was a significant difference in the distribution of postoperative residual stenosis between groups （P<0.001），and the BMS group had a significantly higher non-residual stenosis rate than the DCB group and the PB group （95.9% vs 37.8%/14.3%）. There was no significant difference in 3-month restenosis rate between the BMS group and the DCB group （7.5% vs 17.8%， P=0.129）， and the PB group had a 3-month restenosis rate of 39.3%， which was significantly higher than that in the other two groups （both P<0.05）. There was no significant difference in 6-month restenosis rate between the BMS group and the DCB group （8.2% vs 17.8%， P=0.158）， and the PB group had a 6-month restenosis rate of 39.3%， which was significantly higher than that in the other two groups （both P<0.05）. The good clinical outcome rate at 3 months was 66.7% in the BMS group， 77.8% in the DCB group， and 64.3% in the PB group， with no significant difference between groups （P=0.323）. Conclusion There is no significant difference in 12-month restenosis rate between the three treatment modalities for VAOS， and compared with PB， both BMS and DCB can reduce restenosis rate in patients with VAOS in the short term. BMS has significant clinical advantages in restoration of vascular lumen immediately after surgery.
Stents

Acute ischemic stroke (AIS) is a cerebrovascular disease characterized by high morbidity, disability, and mortality, posing a significant threat to human health. Endovascular treatment has now been established as a key method for AIS management, in which stent retrievers that can mechanically remove blood clots play a key role in this technique. In recent years, stent retrievers have evolved in complexity and functionality to improve the ability of clot removing and surgical safety. However, the present instruments still have limitations on treatment efficiency, vascular adaptability, and operational precision, posing an urgent need for innovation in the design of stent retrievers. This paper systematically reviewed the structural features and working principles of AIS stent retrievers from the perspective of efficacy evaluation metrics, historical development, recent advancements in stent retrieval technology, and future prospects.
Humans ; Ischemic Stroke/surgery* ; Stents ; Endovascular Procedures/methods* ; Thrombectomy/methods* ; Device Removal/methods*