Foreign Body Reaction After Cochlear Implantation: A Case Report.

Foreign body reaction is a rare complication after cochlear implantation. When such complications do occur, they may be intractable and difficult to be cured with antibiotics or surgical revision that may lead to cochlear reimplantation finally. In this article, we presented a patient with foreign body reaction who recovered well after cochlear reimplantation and has been in good health throughout the 6 years of follow‑up at regular intervals in Affiliated Eye Ear Nose and Throat Hospital of Fudan University. A 3‑year‑old boy with profound, idiopathic, sensorineural hearing loss underwent right cochlear implantation with a Nucleus 24 M device (Cochlear Corporation, Australia). After 2 years, seroma, edema occurred above the postauricular implant site. Simultaneously, the patient no longer received auditory benefit from the device. The granulation tissue and involved skin over the implant site were excised, and a new Nucleus 24 K device was reimplanted at the ipsilateral side. Nucleus 24 M and Nucleus 24 K are two different models of cochlear. The intracochlear electrodes of Nucleus 24 M are curved and that of Nucleus 24 K is straight. No postoperative problems were observed during the 6 years of follow‑up. Final culture results were negative. Histology of the granulation tissue surrounding the implant site showed a typical giant cell foreign body inflammatory reaction [Figure 1]. The color of the device was found to be violet and surrounded by granulation tissue during cochlear reimplantation surgery [Figure 2]. Analysis of the old device revealed 5 electrodes anomalies and the bacterial biofilm was not found around the device by scanning electron microscope. Foreign body reaction is diagnosed with typical histologic findings and clinical symptoms. Foreign body reaction, which is composed of macrophage and foreign body giant cells, is the end‑stage response of the inflammatory and wound healing responses following implantation of a medical device, prosthesis, or biomaterial. In the present case, the absence of a positive culture and the bacterial biofilm did not support an infection‑based cause. Therefore, the most likely explanation was a foreign body reaction due to the seroma above the implant site and the histologic finding of a typical giant cell foreign body inflammatory reaction. Lim et al. reported a case of foreign body reaction in 180 cochlear implantees. In addition, Migirov et al. [2] analyzed the causes for revision procedures, surgical findings in 45 reoperated cochlear implant patients. Foreign body reactions were noted in 2 children and 1 adult. Foreign …