[MRI in patients with a cochlear implant: how to proceed]. / MRI bij patiënten met een cochleair implantaat.

MRI in patients with a cochlear implant: how to proceed An increasing number of cochlear implantations are being performed for the treatment of severe sensorineural hearing loss. Implant-associated complications leading to malfunction are of major importance since patients are strongly dependent on their cochlear implant (CI) for communication. Here we describe two patients with a CI who underwent MRI for diagnostic purposes and which resulted in dislocation of the internal CI magnet. CIs are generally non-compatible with MRI. However, by taking precautionary measures it is possible to perform MRI under certain conditions, depending on the type of CI and the magnetic flux density of the MRI scanner. When using 1.5 Tesla equipment, a firm bandage is required to prevent the CI magnet from dislocating. If 3 Tesla equipment is used, almost all CIs must be surgically removed prior to scanning. Despite these precautionary measures, the risk of complications still exists. Patient, referring physician and radiologist should be aware of the risks and disadvantages of performing MRI in patients with a CI.

Retrospective complication rate comparison between surgical techniques in paediatric cochlear implantation.

OBJECTIVE: To compare paediatric complication occurrence between the Mastoidectomy with Posterior Tympanotomy and the SupraMeatal Approach for cochlear implantation. DESIGN: Retrospective cohort study. SETTING: Children receiving a cochlear implant before 5 years of age between 1996 and 2014 in our tertiary center. PARTICIPANTS: A total of 144 patients receiving a cochlear implant (121 by Mastoidectomy with Posterior Tympanotomy and 23 by SupraMeatal Approach) operated on 165 ears (129 and 39 respectively). MAIN OUTCOME MEASURES: The severity (minor or major) using Cohen and Hoffman criteria and time of occurrence of complications (intraoperative, early postoperative or late postoperative) were identified. Intraoperative surgical challenges were correlated to complication occurrence. RESULTS: The mean age at implantation was 2.13 ± 1.14 years old. Patients operated by the SupraMeatal Approach (1.27 ± 0.69 years old) were significantly (P < .001) younger than those receiving a cochlear implant by Mastoidectomy with Posterior Tympanotomy Approach (2.40 ± 1.12). Most complications were minor (Mastoidectomy with Posterior Tympanotomy Approach: 64.0%; SupraMeatal Approach: 73.1%) and occurred early postoperatively (Mastoidectomy with Posterior Tympanotomy Approach: 61.5%; SupraMeatal Approach: 76.9%). More overall complications occurred in SupraMeatal compared to Mastoidectomy with Posterior Tympanotomy Approach cases (61.5% versus 20.6%; P < .001). Younger SupraMeatal Approach cohort patients (6 - 12 and 18 - 24 months; P < .008 and P = .016) most often developed these complications. When looking at specific complications, more infectious complications occurred in patients receiving a cochlear implant through the SupraMeatal Approach (P < .05). Logistic regression showed that the surgical technique and not the age at implantation was responsible for the documented complications. No relationship between complications and intraoperative difficulties was identified. CONCLUSION: In our institution, cochlear implantation in young patients through the SupraMeatal Approach resulted in significantly more (infectious) complications than those operated through the Mastoidectomy with Posterior Tympanotomy Approach. Outcomes from our institution recommends using the Mastoidectomy with Posterior Tympanotomy Approach when opting for a cochlear implant surgical technique in young children who are more prone to develop infectious complications.