Recent years have observed a significant increase in the use of degradable materials in medicine due to their minimal impact on the patient and broad range of applicability. The biodegradable polymer Polydioxanone (PDO) provides a good example of the use of such one polymer that can represent the aforementioned medical materials in the field of medicine, due to its high level of biocompatibility and interesting mechanical properties. PDO is used to produce absorbable medical devices such as sutures and stents, and is also suitable for the fabrication of certain orthopedic implants. Polydioxanone can be processed using the injection molding method due to its thermoplastic nature; this method allows for the precise and easily-controllable production of medical materials without the need for toxic additives. A number of small commercial polymer implants have recently been introduced onto the market based on this processing method. It is important to note that, to date, no relevant information on the molding of PDO is available either for the scientific or the general public, and no study has been published that describes the potential of the injection molding of PDO. Hence, we present our research on the basic technological and material parameters that allow for the processing of PDO using the laboratory microinjection molding method. In addition to determining the basic parameters of the process, the research also focused on the study of the structural and mechanical properties of samples based on the thermal conditions during processing. A technological frame work was successfully determined for the processing of PDO via the microinjection molding approach that allows for the production of samples with the required homogeneity, shape stability and surface quality in a laboratory scale. The research revealed that PDO is a polymer with a major share of crystalline phases, and that it is sensitive to the annealing temperature profile in the mold, which has the potential to impact the final crystalline structure, the fracture morphology and the mechanical properties.

• Keywords
• biopolymers, degradable polymers, injection molding, mechanical properties, medical devices, polydioxanone,
• Publication type
• Journal Article MeSH

OBJECTIVES: To assess mid-term outcome of biodegradable biliary stents (BBSs) to treat benign biliary strictures refractory to standard bilioplasty. METHODS: Institutional review board approval was obtained and patient consent was waived. 107 patients (61 males, 46 females, mean age 59 ± 16 years), were treated. Technical success and complications were recorded. Ninety-seven patients (55 males, 42 females, aged 57 ± 17 years) were considered for follow-up analysis (mean follow-up 23 ± 12 months). Fisher's exact test and Mann-Whitney U tests were used and a Kaplan-Meier curve was calculated. RESULTS: The procedure was always feasible. In 2/107 cases (2 %), stent migration occurred (technical success 98 %). 4/107 patients (4 %) experienced mild haemobilia. No major complications occurred. In 19/97 patients (18 %), stricture recurrence occurred. In this group, higher rate of subsequent cholangitis (84.2 % vs. 12.8 %, p = 0.001) and biliary stones (26.3 % vs. 2.5 %, p = 0.003) was noted. Estimated mean time to stricture recurrence was 38 months (95 % C.I 34-42 months). Estimated stricture recurrence rate at 1, 2, and 3 years was respectively 7.2 %, 26.4 %, and 29.4 %. CONCLUSION: Percutaneous placement of a BBS is a feasible and safe strategy to treat benign biliary strictures refractory to standard bilioplasty, with promising results in the mid-term period. KEY POINTS: • Percutaneous placement of a BBS is 100 % feasible. • The procedure appears free from major complications, with few minor complications. • BBSs offer promising results in the mid-term period. • With a BBS, external catheter/drainage can be removed early. • BBSs represent a new option in treating benign biliary stenosis.

• Keywords
• Biliary stricture, Bioabsorbable biliary stent, Percutaneous transhepatic bilioplasty, Percutaneous transhepatic cholangiography,
• MeSH
• Prosthesis Implantation * MeSH
• Middle Aged MeSH
• Humans MeSH
• Follow-Up Studies MeSH
• Biliary Tract Diseases surgery   MeSH
• Recurrence MeSH
• Retrospective Studies MeSH
• Constriction, Pathologic surgery   MeSH
• Stents * MeSH
• Absorbable Implants * MeSH
• Treatment Outcome MeSH
• Biliary Tract MeSH
• Check Tag
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Female MeSH
• Publication type
• Journal Article MeSH