A newly designed plastic stent for EUS-guided hepaticogastrostomy: a prospective preliminary feasibility study (with videos).

BACKGROUND: There are currently no dedicated plastic stents for EUS-guided hepaticogastrostomy (EUS-HGS). OBJECTIVE: We prospectively evaluated the feasibility and the technical and functional success rates of our newly designed plastic stent for EUS-HGS. DESIGN: Prospective preliminary feasibility study. SETTING: A tertiary-care referral center. PATIENTS: Twenty-three consecutive patients were treated. The reasons for requiring EUS-HGS were periampullary tumor invasion (n=9), altered anatomy (n=7), failed duodenal intubation (n=3), and previous ERCP failure (n=4). INTERVENTIONS: An 8F single-pigtail plastic stent with 4 flanges was placed for EUS-HGS. MAIN OUTCOME MEASUREMENTS: Technical success, clinical success, and adverse events according to the American Society for Gastrointestinal Endoscopy lexicon. RESULTS: All stents were successfully deployed without procedural adverse events (100% technical success rate). Bleeding from the punctured gastric wall occurred in 1 patient 3 days postoperatively. We exchanged the plastic stent for a fully covered self-expandable metal stent. A mild adverse event of self-limited abdominal pain occurred in 3 patients. Treatment success was achieved in all patients. The occlusion rate was 13.7% (3/22) during the median follow-up period (5.0 months, range 0.5-12.5 months). The median duration of stent patency was 4.0 months (range 0.5-9.0 months). There was no stent migration or dislocation during the follow-up period. LIMITATIONS: Small number of patients and lack of a control group. CONCLUSIONS: This newly designed single-pigtail plastic stent dedicated for EUS-HGS was technically feasible and can possibly be used for highly selected patients with advanced malignancy or benign stricture. ( TRIAL REGISTRATION: http://www.umin.ac.jp/english/: UMIN000012993.).

Initial evaluation of a new plastic pancreatic duct stent for endoscopic ultrasonography-guided placement.

There are currently no plastic pancreatic duct stents that have been designed for endoscopic ultrasonography (EUS)-guided placement. This study prospectively evaluated the feasibility and efficacy of a new, single-pigtail, plastic stent. Eight patients with main pancreatic duct stricture or stenotic pancreatojejunostomy underwent EUS-guided placement of the pancreatic duct stent. The stent was placed successfully in all cases (8/8). Treatment success was achieved in all cases (8/8). A mild adverse event associated with the procedure was observed in one patient but there were no other adverse events during a mean follow-up of 7.4 months. This new pancreatic duct stent appears to be feasible and effective for EUS-guided stenting.

Endoscopic ultrasound-guided placement of plastic vs. biflanged metal stents for therapy of walled-off necrosis: a retrospective single-center series.

BACKGROUND AND STUDY AIMS: Recently, a novel fully covered and biflanged metal stent (BFMS)dedicated to the drainage of walled-off necrosis(WON) was developed. The aim of this study was to retrospectively evaluate the safety, efficacy, and cost performance of drainage of WON using the novel BFMS compared with a traditional plastic stent. PATIENTS AND METHODS: A total of 70 patients with symptomatic WON were treated under endoscopic ultrasound (EUS) guidance. Initial drainage was conducted using the single gateway technique with placement of one or more plastic stents or a single BFMS.If drainage was unsuccessful,direct endoscopic necrosectomy (DEN)was performed. RESULTS: There were no statistically significant differences in rates of technical success, clinical success,and adverse events between plastics stents and BFMS, despite the size of WON in the BFMS group being significantly larger than that in the plastic stent group (105.6 vs. 77.1 mm; P=0.003).The mean procedure times for the first EUS-guided drainage and for re-intervention were significantly shorter in the BFMS group than in the plastic stent group (28.8±7.1 vs. 42.6±14.2, respectively,for drainage, P<0.001; and 34.9±8.5 vs.41.8±7.6, respectively, for re-intervention, P<0.001). There was no statistically significant difference in the total cost between plastic stent and BFMS use in the treatment of WON ($5352vs. $6274; P=0.25). CONCLUSIONS: Plastic stents and BFMS were safe and effective for the treatment of WON. In particular,BFMS placement appeared to be preferable for initial EUS-guided drainage and additional reintervention(e.g. DEN) as it reduced the procedure time. Prospective randomized controlled trials are warranted.

Rose bengal-decorated rice husk-derived silica nanoparticles enhanced singlet oxygen generation for antimicrobial photodynamic inactivation.

Rice husks are well known for their high silica content, and the RH-derived silica nanoparticles (RH NPs) are amorphous and biocompatible; therefore, they are suitable raw materials for biomedical applications. In this study, rose bengal-impregnated rice husk nanoparticles (RB-RH NPs) were prepared for their potential photosensitization and 1O2 generation as antimicrobial photodynamic inactivation. RB is a halogen-xanthene type's photosensitizer showing high singlet oxygen efficiency, and the superior photophysical properties are desirable for RB in the antimicrobial photodynamic inactivation of bacteria. To enhance the binding of anionic RB to RH NPs, we conducted cationization for the RH NPs using polyethyleneimine (PEI). The control of the RB adsorption state on cationic PEI-modified RH NPs was essential for RB RH-NP photosensitizers to obtain efficient 1O2 generation. Minimizing RB aggregation allowed highly efficient 1O2 production from RB-RH NPs at the molar ratio of RB with the PEI, XRB/PEI. = 0.1. The RB-RH NPs have significant antimicrobial activity against Streptococcus mutans compared to free RB after white light irradiation. The RB-RH NP-based antimicrobial photodynamic inactivation can be employed effectively in treating Streptococcus mutans for dental applications. Supplementary Information: The online version contains supplementary material available at 10.1007/s10853-023-08194-z.

Mechanical properties and biocompatibility of titanium with a high oxygen concentration for dental implants.

In order to improve the strength of commercially pure Ti (CP-Ti) for oral implants, the high oxygen content Ti (HOC-Ti) was prepared via powder metallurgy. Its composition and mechanical properties were then characterized. After surface treatment by sandblasting and acid etching (SLA), the surface morphology, wettability and roughness of the HOC-Ti and CP-Ti sample were examined. In an in vitro test that followed an evaluation of the protein adsorption capacity of HOC-Ti, the mouse preosteoblast cells were inoculated onto the specimens to evaluate their biocompatibility, in comparison with those of CP-Ti. The oxygen concentration of the HOC-Ti increased to 0.62 wt%, which is higher than the 0.26 wt% of the CP-Ti, while their compositions and microstructures were very similar. The tensile and compressive yield strength of the HOC-Ti (800 MPa) was improved significantly in comparison to that of the CP-Ti (530 MPa). After surface treatment, a unique structure of micropores with a diameter of 380 nm was observed on the entire surface of the HOC-Ti that facilitates cell adhesion and proliferation. The wettability of the HOC-Ti was obviously superior (p < 0.05). The in vitro study showed that the MC3T3-E1 cells inoculated on the surface of HOC-Ti exhibited a homogeneous microstructure, and the viability was higher than that of the control group on days 4 and 7 (p < 0.05). In addition, the number and differentiation activity of cells that adhered to the surface of the HOC-Ti increased significantly on day 7 (p < 0.05). The experimental results showed that, in view of its mechanical properties and biocompatibility, HOC-Ti is superior to CP-Ti and is promising for oral implant applications.