Stent Application Research Articles

3D printed polycaprolactone/poly (L-lactide-co-ε-caprolactone) composite ureteral stent with biodegradable and antibacterial properties.

The clinical application of biodegradable ureteral stents holds significant potential. There is an urgent need to develop new materials for ureteral stents to address the limitations related to performance degradation and antibacterial properties observed in current designs. Here, we developed a Polycaprolactone (PCL)/Poly (L-lactide-co-ε-caprolactone) (PLCL) composite ureteral stent by 3D printing, which exhibits biodegradable and antibacterial properties. Silver nanoparticles (AgNPs) were bonded to the surface of the stent through the polymerization of dopamine (PDA) and coating with type I collagen (Col I). The ureteral stent (PP-PDA-Ag-Col) had a densely spiraled structure and higher hydrophilicity. The release behavior of silver ions from the stent was found to be slow and continuous when coated with AgNPs, which can enable long-term antibacterial effects after being implanted in vivo. Additionally, in vitro degradation experiments demonstrated that the different ratios of ureteral stents degraded slowly in artificial urine over 6 weeks without compromising functionality. The stent exhibits excellent hemocompatibility and cell compatibility. The subcutaneous implantation experiment in SD rats showed that the PP-PDA-Ag-Col stent degraded slowly in vivo and had good biocompatibility. The stent PCL5/PLCL5 was the most promising ureteral stent regarding antibacterial, mechanical properties, and degradation. The novel 3D-printed PP-PDA-Ag-Col stent exhibits biocompatibility for safe in vivo transplantation and antibacterial properties that reduce reliance on antibiotics. Additionally, its biodegradability eliminates the need for secondary surgical removal, making it a promising option for the clinical application of ureteral stents.

Enhancement of Antibacterial and Hydrophilic Properties of LDPE Surfaces by Benzoxazine‐Chitosan Coatings: Structure and Performances

ABSTRACTAlthough low‐density polyethylene (LDPE) proved its efficacy in alleviating biliary obstruction stemming from biliopancreatic conditions as biliary stents, the problem of stent occlusion resulting from insufficient antibacterial and hydrophilic properties remains worth investigating. In this study, polydopamine (PDA) and poly(ethylene glycol) bis(carboxymethyl) ether (PEGb) were used as anchors on the LDPE surface, and then chitosan‐benzoxazine (CSxBzy) coatings were grafted with PEGb to obtain an innovative surface to enhance the antimicrobial and hydrophilic features of LDPE. The antimicrobial abilities of PE‐CSxBzy were evaluated by co‐culture and plate coating techniques, demonstrating a remarkable inhibitory effect of up to 99.3% against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). The field emission scanning electron microscopy (SEM) and the laser confocal scanning microscope further demonstrated that the PE‐CSxBzy has excellent anti‐bacterial adhesion properties. Compared to pristine LDPE, the amount of adherent bovine serum albumin (BSA) and the number of bile proteins on the PE‐CSxBzy surface were reduced by up to 64.56% and 80.26%, respectively. PE‐CSxBzy exhibited excellent and stable hydrophilicity, with a water contact angle of approximately 50°, which only increased by 18.84% even after 30 days of immersion. PE‐CSxBzy also showed complete biocompatibility with human biliary epithelial cells (BECs) and anticipation for biliary stent materials considering its exceptional hydrophilicity and antibacterial abilities. Moreover, the molecular dynamics simulations further demonstrated that the antibacterial properties and hydrophilic capabilities arise from the synergistic effect of chitosan‐benzoxazine coating structures. This study, we suggest, presents recommendations for regulating the antimicrobial and hydrophilic properties associated with LDPE materials utilized in biliary stent applications.

Assessing the Potential of Gel–SA–MgHA Composite Biomaterial Ink for 3D Bioprinting Tracheal Stents

AbstractDiseases such as injury, stenosis, and tumors of the long trachea usually require the removal of the affected part of the trachea. There is an urgent need to implant tracheal stents as substitutes in clinical practice. In this paper, Mg2+ was first doped into hydroxyapatite (HA) matrix by hydrothermal synthesis and then mixed with gelatin sodium alginate (Gel–SA) double network crosslinked hydrogel to prepare gelatin sodium alginate magnesium doped hydroxyapatite (Gel–SA–MgHA) composite biomaterial ink. The trachea stent was prepared by 3D bioprinting technology and its physicochemical, mechanical, and biological properties were systematically evaluated. Due to the large number of hydrophilic groups on the surface of the HA matrix, the addition of MgHA improved the hydrophilicity of tracheal stents. The mechanical properties of the stent first increase and then decrease with the increase of MgHA content. When the MgHA content is 4 wt%, the tracheal stent has the optimal mechanical properties. In vitro cytology experiments have confirmed that the four stent materials have good cell compatibility and proliferation characteristics. Overall, Gel–SA–4MgHA has the best mechanical and cytological properties, and has certain potential in the clinical application of tracheal stents.

Extended intrauterine balloon stent use to prevent adhesion reformation after hysteroscopic adhesiolysis: A randomized trial.

To evaluate the efficacy and safety of retaining a balloon stent in the uterus for 8 weeks to prevent adhesion reformation after hysteroscopic adhesiolysis. A single-center randomized controlled study. A total of 160 women with severe intrauterine adhesions (American Fertility Society [AFS] intrauterine adhesion scores ≥9, and European Society for Gynaecological Endoscopy Grade ≥IV). The participants were randomized 1:1 into two groups. In the study group, the balloon stent was left in place for 8 weeks after surgery and removed at the second-look hysteroscopy, with a third-look hysteroscopy performed 4 weeks later. In the control group, the balloon stent was maintained for 1 week, with participants undergoing second- and third-look hysteroscopies at 4 weeks and 8 weeks postoperatively, respectively. Among 160 randomized patients, 136 (69 and 67 in the study and control groups, respectively) completed the study. The primary outcome was the adhesion recurrence rate upon third-look hysteroscopy. On third-look hysteroscopy, the adhesion reformation was significantly lower in the study group than in the control group (17.4% vs. 43.3%; relative risk, 0.40; 95% confidence interval, 0.22-0.72; rate difference, -25.89%; 95% confidence interval, -40.75 to -11.04%). Additionally, the reduction in AFS adhesion scores was significantly larger in the study group than in the control group (10 vs. 7, P<.001). The outcomes of the second- and third-look hysteroscopies were consistent. No safety concerns were observed regarding extended stent placement. In this randomized controlled study, extending the balloon stent application to 8 weeks proved an effective and safe method for preventing adhesion reformation after hysteroscopic adhesiolysis for severe intrauterine adhesions.

VACStent closure of oesophageal defects by covered stent and endoscopic vacuum therapy: initial use and clinical outcomes

Abstract Endoscopic management of transmural oesophageal defects following esophagectomy or spontaneous perforations, such as Boerhaave’s syndrome, is often complicated by stent migration and luminal occlusion [1]. The Vacuum-Assisted Closure (VAC) stent, which integrates a covered stent with endoscopic vacuum therapy, aims to address these issues by providing functional drainage and promoting wound healing [2]. This case series presents our initial experience with VACStent therapy in four patients treated between February 2023 and April 2024. Two patients had staple line defects post-esophagectomy, and two had Boerhaave’s syndrome. Treatment involved stent placement under general anaesthesia, followed by evaluations and scheduled stent exchanges every 6 days. All patients achieved successful defect closure, with no procedural complications noted. Three patients required one stent application, while one needed two applications. VACStent therapy appears to be a safe and effective treatment for transmural oesophageal defects, potentially establishing a new standard of care.

Bare metal stent application to prevent limb occlusion in iliac arteries with severe tortuosity during an endovascular aneurysm repair: a cohort study.

The risk of limb graft occlusion (LGO) after endovascular aneurysm repair (EVAR) is increased by severe tortuosity of the iliac artery. A bare metal stent (BMS) may protect LGO, according to the hypothesis of this single-center retrospective analysis. All patients undergoing elective EVAR with a bifurcated stent graft between January 2012 and June 2022 were included in this cohort study. Patients demonstrating significant tortuosity at the iliac angle were incorporated into this study and classified into two groups: group A comprised those who received a BMS. In contrast, group B consisted of those who did not receive a BMS. The primary outcomes were the incidence of limb occlusion and technical success during the follow-up period. However, secondary outcomes included perioperative mortality, external iliac angioplasty, and crossed-limb techniques. This study has been reported as being in line with the STROCSS criteria. A total of 157 patients (mean age = 71.6 ± 8 years) with infrarenal abdominal aortic aneurysms were enrolled. In total, 50 individuals were included in group A, while 107 were in group B. Overall technical success was 100%, and only one (2%) patient from group A and 17 (15%) from group B suffered from limb occlusion during follow-up (p < 0.05). At a mean follow-up imaging duration of 28.7 ± 23.6 months (range 1-124), the estimated primary limb patency at 2 years was 98% for the BMS group and 84% for the non-BMS group (p < 0.05). There were no changes in perioperative mortality or crossed-limb procedures between the BMS and non-BMS groups. Nonetheless, there were disparities in external iliac angioplasty between the two groups during the follow-up period (p < 0.05). Deploying a BMS inside the iliac artery to prevent or treat limb occlusion is a safe and effective strategy, with clear prolonged outcomes concerning patency and re-interventions.

3D printed drug-eluting stents: Toward personalized therapy for airway stenosis

Airway stents are life-saving medical devices used to treat malignant or benign central airway stenoses. Unfortunately, these devices, typically manufactured from silicone alone and/or nitinol, can result in serious complications, such as stent migration, bacterial colonization, and tissue granulation, eventually forcing stent removal. Customized airway stents exhibit reduced migration and they can be tailored to address other complications by releasing drugs, such as the antibiotic levofloxacin and the antifibrotic drug nintedanib. Herein, the incorporation of these molecules in customized, bioresorbable 3D printed airway stents was investigated. Nintedanib (1.5 wt%) and levofloxacin (2.0 wt%) were incorporated in the polymer-based resin, which was used to 3D print tracheal stents with adequate mechanical and drug release properties. The drug-loaded stents were then deployed into rabbit tracheas and found to deliver the drugs locally with minimal systemic exposure. Drug activities were demonstrated by inhibition of bacterial colonization and reduced interleukin 8 (IL8) local expression. Although the application of these tracheal stents requires further exploration in larger animal models, this work paves the way for the rapid manufacturing of personalized medical devices with therapeutic functions.

Application of Drug-Eluting Stent With Drug-Coated Balloon Strategy for the Endovascular Treatment of Long-Segment Femoropopliteal Artery Disease.

Endovascular therapy (EVT) has emerged as a primary approach for managing femoropopliteal artery (FPA) lesions, leveraging drug-eluting stents (DESs), and drug-coated balloons (DCBs), to enhance clinical outcomes. Although a full DES coverage strategy is effective in treating complex lesions, concerns over long-term complications prompt the exploration of alternative strategies. The aim of this study was to investigate clinical result of combination therapy of DES with DCB and compare them with full DES implantation. This retrospective, single-center study analyzed 131 patients with occlusive FPA lesions treated at our institution between 2019 and 2022. Patients with Rutherford classification stages 2 to 5 who underwent successful EVT were included. The study compared the outcomes of the drug-within-drug (DWD) strategy, ie, combining DES for failed vessel preparation segments and DCB for successful ones, with those of full DES implantation. The primary outcomes were the primary patency rates, and the secondary outcomes included clinically-driven target lesion revascularization (CD-TLR) rates, restenosis patterns, and survival outcomes. Of the 131 patients initially considered, 118 met the inclusion criteria, with 45 in the DWD group and 73 in the full metal jacket (FMJ) stent group. The DWD group demonstrated equivalent 1-year primary patency rates (85.3%) to the FMJ group (87.9%, p=0.239). Similarly, no significant differences in CD-TLR rates were found between the 2 groups. The restenosis patterns and subsequent treatment strategies were not significantly different. The DWD strategy offers a viable alternative to full DES coverage in treating long-segment FPA lesions, with comparable restenosis and target lesion revascularization (TLR) rates. This approach may mitigate risks associated with full-length stenting, such as thrombosis, and challenges in repeat revascularizations by tailoring treatment to lesion characteristics. The DWD strategy represents a promising approach for complex FPA lesions, providing a balanced solution that potentially reduces long-term complications while maintaining effective patency and revascularization rates. The efficacy of drug-eluting stents (DES) in treating femoropopliteal artery (FPA) lesions has been well demonstrated. However, concerns remain regarding complications such as thrombotic occlusion and aneurysmal degeneration, especially when full stemt coverage of whole lesions is performed. The "Drug-with-Drug" (DWD) strategy, which involves implanting DES only at sites with severe dissection or residual stenosis after pre-balloon dilation and using drug coated balloons (DCB) for segments successfully prepared without stenting, has shown comparable outcomes to full stent coverage. Unlike traditional bailout stenting or spot stenting, the DWD approach maximizes the benefits of drug technology and presents a valuable option for treating long-segment FPA lesions.

Effect of process variables on Ultimaker 2+ 3D FDM printed Tough PLA parts

ABSTRACT Fused Deposition Modeling (FDM) is pivotal in creating functional prototypes and end-use parts, with Tough PLA emerging as a favored material due to its durability. However, fine-tuning printing process variables for Tough PLA on the Ultimaker 2 + 3D printer remains challenging. This study employs Taguchi Grey relational analysis to optimize these process variables. L09 Taguchi’s systematic approach and Taguchi Grey Relational Grade Analysis (TGRGA) investigated Layer Thickness (LT), Infill Density (ID), and Nozzle Temperature (NT) at varying levels for which response variables such as Ultimate Tensile Strength (UTS), Average hardness (AH), and Surface Roughness (Ra) are evaluated. Utilizing Taguchi Grey Relational Grade Analysis (TGRGA), enhancements in ultimate tensile strength from 43.182 N/mm2 to 46.56 N/mm2, average hardness from 64 to 67, and Surface roughness from 8.60 µm to 8.35 µm are achieved. This study contributes to advancing additive manufacturing optimization, offering insights into refining Tough PLA part production on the Ultimaker 2 + 3D printer for bio implants like stent application.

Evaluating the Biodegradability and Cellular Compatibility of Mg-Zn-Nd Alloy for Vascular Stent Application.

The study is designed to evaluate the corrosion behavior, biocompatibility, and cytotoxicity of a novel magnesium alloy, Mg-2Zn-0.5Nd (ZN20), for potential use as biodegradable scaffolding in cerebrovascular stents. Magnesium alloy (AZ31) and ZN20 are co-cultured with Human Umbilical Vein Endothelial Cells (HUVEC)and human neuroblastoma cell (SH-SY5Y), respectively. The corrosion of AZ31 and ZN20 in different time periods is detected by electron microscope, the effects of AZ31 and ZN20 on the expression level of inflammatory factors are detected by ELISA, the PH value of cells in each group is detected, and the cell proliferation is detected by cck-8. Cell-related apoptosis protein, the expression of Platelet endothelial cell adhesion molecule-1 (CD31)and VE-cad is detected, and the pathological analysis of rat vascular tissue is carried out by HE experiment. In contrast to the AZ31 group, ZN20 exhibits mild, uniform corrosion and does not significantly deter HUVEC proliferation or increase inflammatory markers and In vivo testing reveals better endothelization with ZN20, as demonstrated by higher expression of endothelial markers CD31, and intact endothelial structure group. Western blotting shows favorable expression levels of apoptotic and anti-apoptotic markers in the ZN20 group. ZN20 alloy demonstrates enhanced corrosion resistance, favorable endothelial compatibility, and reduced cytotoxicity, endorsing its safe application in vascular stent use.

3D Printed Stent from Graphene-Polyethylene Glycol Diacrylate Using Digital Light Processing Technique

Abstract This paper presents the development of the photocurable resin material based on the graphene reinforced polyethylene glycol diacrylate (gPEGDA) for vascular stent fabrication using a commercial 3D printer. 3D printing with digital light processing (DLP) technique is an attractive alternative for low-cost fast fabrication with high accuracy. Four photocurable resin compositions were prepared by mixing PEGDA and varied composition of graphene and the photoinitiator according to the design of experiment of 22 full factorial design. The diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide (TPO) photoinitiator was adopted to meet the required 405 nm UV-light source wavelength of the 3D printer for stent fabrication. Material characterization of the UV-absorbance and viscosity tests were conducted and optimized to obtain resin printability. Mechanical characteristics tests were conducted to obtain the best resin composition for stent application. For this purpose, the tensile tests were conducted according to the ASTM D638 standard using the type-V specimen size. The test specimens were 3D printed with varied UV exposure time 20 and 30 seconds. Finally, the stents were successfully fabricated using a commercial 3D printer DLP with the bottom parameter time setting of 60 seconds, and the UV exposure time of 30 seconds. The resin material was applicable for 3D printing of the stent. The result has shown that 3D printer with DLP technique is suitable for stent fabrication with excellent surface quality. Moreover, the innovative bioresorbable stent materials and fabrication approach could open up new possibilities in the development of medical devices, particularly in the treatment of vascular diseases.

Advancing biodegradable Mg-Gd-Y alloy for cardiovascular stent applications

The implants of percutaneous coronary intervention are making progress to periodic degradation and the reduction of complications. Thus, magnesium alloys have emerged as excellent candidate materials for preparing cardiovascular stents due to their excellent biodegradability and biocompatibility. This study investigates the effect of Gd content on the mechanical properties and corrosion behavior of Mg-xGd-5Y alloys. The results indicate that Gd dissolved in the Mg matrix, enhancing ultimate tensile strength (UTS of 344 MPa) through a solid solution-strengthening effect and activating Prismatic <a> slip systems to enhance elongation (EL of 15.7 %). The Pilling-Bedworth ratio (PBR) of Mg-xGd-5Y alloys was analyzed after being immersed in Hank's Balanced Salt Solution for 24 h, with Mg-10Gd-5Y exhibiting a PBR value of 1.1. Furthermore, the product film of Mg-xGd-5Y alloys, mainly oxides and carbonates, effectively improved corrosion resistance. Mg-xGd-Y alloys with low Gd content (Gd≤10 wt%) demonstrated good cell compatibility with L929 cells (relative growth rate≥75 %). These results suggest that Mg-xGd-5Y alloys (Gd≤10 wt%) have significant potential for cardiovascular stent application.

Evaluation with spiral computed tomography angiography after intravascular stent application in atherosclerotic renal artery stenosis

Evaluation with spiral computed tomography angiography after intravascular stent application in atherosclerotic renal artery stenosis

Failure signal of high orientation Poly(L-lactic acid) monofilament for self-expanding stent during lifetime: Disappeared amorphous connections

The premature failure of bioresorbable self-expanding stents for peripheral arterial disease could lead to form thrombosis and threaten patients′ lives. Predicting the time and cause of mechanical and structural failure is crucial to prevent premature failure of implanted stents. Herein, we report a situ accelerated hydrolysis to investigate the degradation properties of self-expanding stents braided by high-performance Poly(L-lactic acid) (PLLA) monofilaments in an accelerated term over a formal long one. Degradation, microstructure, and mechanical properties were comprehensively evaluated to identify key factors of the failure during lifetime. The results show that the upper temperature limit for accelerated hydrolysis is 50 °C. The mechanical properties undergo multiple stages of functional holding, decreasing, and eventual failure. It is attributed to uneven degradation and distribution of crystalline and amorphous regions. Specifically, the disappearance of amorphous chains between fibrils at 6 months leads to mechanical failure. Further disappearance of amorphous chains within fibrils at 18 months results in structural disintegration. Additionally, the degradation behavior of the stents and potential effects of degradation products on vascular tissues are validated for predictive accuracy. These insights provide valuable experimental references for optimizing design and clinical application of PLLA-based self-expanding stents.

Fabrication of Zn-0.5Mn-0.05 Mg Micro-Tube with Suitable Strength and Ductility for Vascular Stent Application

Fabrication of Zn-0.5Mn-0.05 Mg Micro-Tube with Suitable Strength and Ductility for Vascular Stent Application

Reactive oxygen species-responsive coating based on Ebselen: Antioxidation, pro-endothelialization and anti-hyperplasia for surface modification of cardiovascular stent

Atherosclerosis is often accompanied by inflammation and oxidative stress. Excessive reactive oxygen species (ROS) can damage the vascular endothelium, leading to endothelial dysfunction and reduced nitric oxide (NO) bioavailability. Further accumulation of ROS contributes to vascular cell damage, lipid peroxidation, and extracellular matrix deposition. Thus, clearing excess ROS and reshaping the oxidative microenvironment is essential for treating atherosclerosis (AS). In this study, Ebselen, which mimics glutathione peroxidase and possesses redox capabilities, was successfully synthesized. Subsequently, a multifunctional coating was designed using a combination of Ebselen and poly (trimethylene carbonate) (PTMC), capable of protecting cells from ROS-induced damage, promoting vascular endothelialization, and exhibiting anti-proliferative properties. The Ebselen-loaded coating effectively scavenges free radicals (with an elimination rate of 89 %), catalytically releases NO (0.96 × 10⁻¹⁰ to 1.26 × 10⁻¹⁰ mol/cm²/min), and sustainably delivers Ebselen to the lesion site through a redox cycle. Notably, this coating shows excellent hemocompatibility and cytocompatibility. Subcutaneous implantation results indicated that the fibrous capsule thickness of PTMC10 was the lowest, at just 47.7 % of that of PTMC. Therefore, the Ebselen-loaded coating presents promising applications in cardiovascular stents.

Balloon Angioplasty and Stenting of Superior Mesenteric Artery in Chronic Intestinal Ischemia Associated with Decompensated Chronic Heart Failure (Clinical Case Report)

INTRODUCTION: Chronic intestinal ischemic syndrome (CIIS) is a pathology associated with chronic circulatory insufficiency in the visceral branches of the abdominal aorta. Duplex ultrasound can be used as the first imaging method to identify mesenteric artery stenosis. In general clinical practice, the diagnosis of CIIS is relatively rare. Expansion of application of percutaneous endovascular angioplasty and stenting of mesenteric arteries in recent years has significantly increased the effectiveness of treating patients with atherosclerotic lesion of the visceral arteries and CIIS. AIM: To demonstrate a clinical case of use of X-ray endovascular technologies in CIIS in a patient of cardiology profile. A clinical case of a patient with CIIS and severe decompensated polymorbidity is presented. Due to severity of the condition and impossibility of full examination for this reason, the patient was not included in the waiting list for heart transplantation despite the existence of indications for it. He was admitted to hospital for urgent indications. Ultrasound data revealed stenosis of the superior mesenteric artery. Balloon angioplasty and stenting of the superior mesenteric artery were successful. After discharge, the patient’s condition was satisfactory. CONCLUSION: The case demonstrates that effective treatment of even one of many comorbid diseases in a severe polymorbidity patient can improve his general condition, reduce load on the cardiovascular system and reverse edematous-ascitic syndrome.

Investigation of mechanical performance for tricuspid valve stent in different compression modes

Abstract The tricuspid acting as a one-way valve between the right atrium and the right ventricle of the human heart, is very important for the blood circulation system. The regurgitation will be induced if the tricuspid cannot close normally, leading to symptoms such as arrhythmia and right heart failure. In the case of severe regurgitation, replacement with an artificial tricuspid valve instead of the natural tricuspid is the promising solution. For the typical artificial tricuspid valve, the bioprosthesis valve is fixed on a tricuspid valve stent which is usually compressed before being implanted into the heart. In this study, numerical simulation with an ABAQUS standard approach is carried out with a focus on the compression process of the tricuspid valve stent to evaluate the mechanical performances of two compression methods: one is the traditional radial compression method (RCM), and another is the axial compression method (ACM) that gradually compresses through a conical channel. The results indicate that the environment temperature is closely related to the stress distribution for both the RCM and ACM, in particular, a lower temperature can result in lower stress. The maximum strain is located at the inner corner of the joint of the stent ribs and the connection between the top arm and the stent, with a value over 12% at the temperature of 0°C, indicating the possible position for failure. The average diameter-stress curves of the RCM and ACM are respectively obtained for the compression process. To achieve long operation time, the RCM is recommended from the perspective of reducing compressive stress. The present study can provide the experience for the production and clinical application of tricuspid valve stents.

Late meningitis and a nonabsorbable stent in recurrent Rathke's cleft cyst: illustrative case.

The management of recurrent Rathke's cleft cysts (RCCs) remains challenging. The off-label application of steroid-eluting bioabsorbable or nonabsorbable intracystic stents has been recently described. Early outcomes and complications of this treatment have been described as well, but long-term data are lacking. A 31-year-old woman who had undergone 3 prior transsphenoidal surgeries for recurrent RCC at other institutions was admitted for methicillin-susceptible Staphylococcus aureus meningitis. Five years earlier, a nonabsorbable stent had been placed in the cyst using a microsurgical transsphenoidal approach. RCC recurrence had been radiologically evident after 2 years but was clinically asymptomatic. Acute cerebrospinal fluid leakage and other causes of meningitis were ruled out; the stent was occluded. After antibiotic therapy and resolution of the meningitis, the patient underwent endoscopic removal of the catheter, excision of the cyst, and reconstruction with a nasoseptal flap. At the 18-month follow-up, she remained neurologically intact, under replacement therapy, and with no signs of recurrence. The authors report the first case of late meningitis due to a nonabsorbable stent positioned for the treatment of a recurrent RCC. Currently, data on the long-term outcomes, failure rates, and complications of stents for RCC are limited. https://thejns.org/doi/10.3171/CASE2477.

The quality of life after keratinized mucosa augmentation around dental implants using xenogenic collagen matrix with or without stent.

The substitution of missing teeth with implants is a dependable and anticipated therapeutic approach. Despite numerous studies affirming long-term success rates, there exists a spectrum of potential biological and aesthetic complications. The primary objective of this study was to assess patient responses subsequent to surgical interventions, with a specific emphasis on the utilization of xenogenic collagen matrix (XCM), both with and without the application of a stent secured over healing abutments, in the context of keratinized gingival mucosa augmentation. The principal aim was to evaluate and draw comparisons between the clinical outcomes resulting from these two procedural approaches, with a particular focus on critical parameters encompassing post-operative complications, patient comfort, and the overall efficacy in achieving successful keratinized tissue augmentation. Sixty patients were selected for this study. The patients were divided into three groups: A, B, and a control group, with each group comprising 20 participants. We used XCM in experimental group A, XCM covered with surgical stent in experimental group B, and free gingival graft (FGG) in the control group. After the surgical procedure, patients were required to complete a visual analogue scale (VAS) questionnaire for post-operative complications, and a quality of life (QOL) questionnaire on days 1, 3, and 7. Patients in the experimental groups A and B demonstrated markedly improved outcomes when compared with the control group. Assessments conducted on days 1, 3, and 7 demonstrated diminished levels of pain, bleeding, and swelling in both experimental groups, with experimental group B showing the least discomfort. The incorporation of XCM, either with or without stents, was associated with a reduction in analgesic consumption, underscoring its favorable influence on post-operative comfort, notwithstanding the exception of halitosis in experimental group B. Using XCM with or without a stent for keratinized tissue augmentation has better post-operative outcomes associated with reduced swelling, bleeding, and pain based on the QOL survey. This study provides data to support the clinical application of XCM and stents.