title: Effect of a liposomal hyaluronic acid gel loaded with dexamethasone in a guinea pig model after manual or motorized cochlear implantation.
abstract: Goals of cochlear implantation have shifted from complete insertion of the cochlear electrode array towards low traumatic insertion with minimally invasive techniques. The aim of this study was first to evaluate, in a guinea pig model of cochlear implantation, the effect of a motorized insertion technique on hearing preservation. The second goal was to study a new gel formulation containing dexamethasone phosphate loaded in liposomes (DEX-P). Guinea pigs had a unilateral cochlear implantation with either a manual technique (n = 12), or a motorized technique (n = 15), with a 0.4 mm diameter and 4 mm long array trough a cochleostomy. At the end of the procedure, hyaluronic acid gel containing drug-free liposomes, or liposomes loaded with DEX-P, was injected into the bulla. Auditory brainstem responses thresholds were recorded before surgery and day 2 and 7 after surgery. All the animals had increased auditory brainstem responses thresholds after the cochlear implantation. Implanted animals with the motorized insertion tool experienced a partial hearing recovery at day 7 but not in those implanted with the manual insertion procedure (p < 0.001). In the manually implanted animals, a partial recovery was observed when DEX-P contained in liposomal gel was locally administrated (p < 0.0001). Finally, no additive effect with the motorized insertion was noticed. The deleterious effect of manual insertion, during cochlear implantation, can be prevented with local DEX-P administration in the bulla at day 7. The use of a motorized tool performed more atraumatic electrode array insertion for postoperative hearing.
authors.affiliation: UMPC, Paris Sorbonne, INSERM, "Minimally Invasive Robot-based Hearing Rehabilitation", Paris 6, France. elisabeth.mamelle@aphp.fr.|AP-HP, Pitié-Salpêtrière Hospital, Unit of Otology, Auditory Implants and Skull Base Surgery, Otolaryngology Department, 75013, Paris 6, France. elisabeth.mamelle@aphp.fr.
authors.forename: Elisabeth
authors.identifier: http://orcid.org/0000-0001-5263-1064
authors.initials: E
authors.lastname: Mamelle
authors.affiliation: Institut Galien Paris Sud, CNRS 8612, Paris-Sud, Paris-Saclay University, 92290, Châtenay-Malabry, France.
authors.forename: Naila El
authors.initials: NE
authors.lastname: Kechai
authors.affiliation: AP-HP, Pitié-Salpêtrière Hospital, Unit of Otology, Auditory Implants and Skull Base Surgery, Otolaryngology Department, 75013, Paris 6, France.|Department of Public Health, AP-HP, Pitié-Salpêtrière Hospital, 75013, Paris, France.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Granger
authors.affiliation: UMPC, Paris Sorbonne, INSERM, "Minimally Invasive Robot-based Hearing Rehabilitation", Paris 6, France.|AP-HP, Pitié-Salpêtrière Hospital, Unit of Otology, Auditory Implants and Skull Base Surgery, Otolaryngology Department, 75013, Paris 6, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: Sterkers
authors.affiliation: Institut Galien Paris Sud, CNRS 8612, Paris-Sud, Paris-Saclay University, 92290, Châtenay-Malabry, France.
authors.forename: Amélie
authors.initials: A
authors.lastname: Bochot
authors.affiliation: Institut Galien Paris Sud, CNRS 8612, Paris-Sud, Paris-Saclay University, 92290, Châtenay-Malabry, France.
authors.forename: Florence
authors.initials: F
authors.lastname: Agnely
authors.affiliation: UMPC, Paris Sorbonne, INSERM, "Minimally Invasive Robot-based Hearing Rehabilitation", Paris 6, France.|AP-HP, Pitié-Salpêtrière Hospital, Unit of Otology, Auditory Implants and Skull Base Surgery, Otolaryngology Department, 75013, Paris 6, France.
authors.forename: Evelyne
authors.initials: E
authors.lastname: Ferrary
authors.affiliation: UMPC, Paris Sorbonne, INSERM, "Minimally Invasive Robot-based Hearing Rehabilitation", Paris 6, France.|AP-HP, Pitié-Salpêtrière Hospital, Unit of Otology, Auditory Implants and Skull Base Surgery, Otolaryngology Department, 75013, Paris 6, France.
authors.forename: Yann
authors.initials: Y
authors.lastname: Nguyen
mesh_terms: D000818:Animals; D019929:Cochlear Implantation / Q000379:methods*; D003907:Dexamethasone / Q000008:administration & dosage / Q000031:analogs & derivatives*; D016057:Evoked Potentials, Auditory, Brain Stem / Q000502:physiology; D005782:Gels; D005938:Glucocorticoids / Q000008:administration & dosage*; D006168:Guinea Pigs; D006820:Hyaluronic Acid / Q000008:administration & dosage*; D008081:Liposomes; D023421:Models, Animal; D055675:Viscosupplements / Q000008:administration & dosage*
chemical_list: D005782:Gels; D005938:Glucocorticoids; D008081:Liposomes; D055675:Viscosupplements; C004180:dexamethasone 21-phosphate; D003907:Dexamethasone; D006820:Hyaluronic Acid
keywords: Cochlear implant; Hyaluronic acid gel; Liposomes; Local drug delivery; Residual hearing