Taha Kouchakinezhad (Hannover), Farnaz Matin-Mann (Hannover), Ziwen Gao (Hannover), Chunjiang Wei (Hannover), Jana Schwieger (Hannover), Martin Ulbricht (Greifswald), Vanessa Domsta (Greifswald), Stefan Senekowitsch (Greifswald), Werner Weitschies (Greifswald), Anne Seidlitz (Greifswald; Düsseldorf), Katharina Doll (Hannover), Meike Stiesch (Hannover), Thomas Lenarz (Hannover), Verena Scheper (Hannover)
Background:
Reducing the incidence of postoperative external ear canal (EEC) stenosis is crucial after canaloplasties. To explore an innovative solution, we developed three-dimensionally (3D) printed, patient-individualized, drug-releasing external ear canal implants (EECI) as postoperative stents, loaded with dexamethasone (DEX) and ciprofloxacin (cipro).
Methods:
EECI models were manually segmented from temporal bone cone beam computed tomography images and 3D printed using medical-grade UV silicone (60A MG, BIO-83-6001, EnvisionTEC, silicone elastomer curing at 365 nm, USP Class VI). The implants were loaded with DEX and cipro, and pre-clinically tested for drug release, biocompatibility, bio-efficacy, and microbial contamination. Subsequently, individualized EECI were implanted in three patients with congenital EEC atresia, postoperatively acquired EEC stenosis, or EEC restenosis after multiple canaloplasties.
Results:
Preclinical tests confirmed drug release and demonstrated no cytotoxic effects. The UV silicone EECI exhibited anti-inflammatory and antibacterial effects without microbial contamination. Implantation in three patients showed ease of insertion and postoperative explantation at three months with no otogenic symptoms or infections during follow-up visits. Even 12 months postoperatively, the EECs exhibited good epithelialization and patency.
Conclusion:
Our study demonstrates the clinical viability of individualized, mechanically flexible, drug-releasing EECI for preventing postoperative EEC restenosis. Ongoing research involving a larger patient cohort aims to further validate the effectiveness and safety of this novel EECI therapy, providing comprehensive and robust results.
Keywords: ear canal stenosis; personalized implant; drug eluting implant; additive manufacturing
Hintergrund:
Reduktion postoperativer Stenosen des äußeren Gehörgangs (EGC) ist nach Canaloplastiken entscheidend. Ziel: Machbarkeit dreidimensionaler, medikamentenfreisetzender Implantate (DEX, Cipro) als postoperative Stents.
Methoden:
EECI-Modelle manuell aus Digitalen Volumentomographie-Bildern (DVT) segmentiert, mit medizinischem UV-Silikon 3D-gedruckt. Implantate mit DEX und Cipro beladen, präklinisch getestet. Anschließend EECI bei drei Patienten implantiert.
Ergebnisse:
Präklinische Tests bestätigten Medikamentenfreisetzung ohne Zytotoxizität. EECI zeigten entzündungshemmende, antibakterielle Effekte ohne Kontamination. Implantation und explantation verliefen komplikationsfrei. Nach 12 Monaten gute Epithelialisierung und Offenheit.
Schlussfolgerungen:
Klinische Umsetzung individualisierter, medikamentenfreisetzender EECI stellt sichere Methode zur postoperativen Stentung dar.
Schlüsselwörter:
Gehörgangsstenose; personalisiertes Implantat; medikamentenfreisetzendes Implantat; additive Fertigung
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