From the Guidelines
To manage a perilymphatic leak during cochlear implantation, the surgeon must immediately identify and seal the leak, typically using soft tissue grafts and fibrin glue or tissue adhesives to patch the leak site. The most common approach is to use soft tissue grafts such as fascia, muscle, or fat harvested from the patient to patch the leak site. Fibrin glue or tissue adhesives like Tisseel may be applied to reinforce the seal. In some cases, the surgeon will place additional support materials such as bone wax, bone dust, or bone pâté around the cochleostomy or round window to ensure complete closure. The patient's head should be positioned with the affected ear up for 24-48 hours post-surgery to reduce pressure on the repair site. Bed rest for 24-72 hours is typically recommended, along with instructions to avoid straining, heavy lifting, or nose blowing for 1-2 weeks. Stool softeners like docusate sodium 100mg twice daily may be prescribed to prevent straining. Some surgeons prescribe prophylactic antibiotics such as amoxicillin/clavulanate 875/125mg twice daily for 7-10 days to prevent infection, as children with cochlear implants may be at increased risk of acquiring bacterial meningitis compared with children in the general US population 1. Prompt repair is critical because persistent perilymph leakage can lead to hearing loss, vestibular dysfunction, and increased risk of meningitis due to the creation of a potential pathway for bacteria from the middle ear to the inner ear and cerebrospinal fluid. It is essential to follow the CDC recommendations for pneumococcal immunization and age-appropriate Haemophilus influenzae type b vaccines for children with cochlear implants 1. The provided evidence on preventing central line-associated bloodstream infections 1 and audiological habilitation 1 is not directly relevant to the management of perilymphatic leaks during cochlear implantation. Therefore, the management of perilymphatic leaks should focus on prompt identification and sealing of the leak, followed by post-operative care to prevent complications and promote healing.
From the Research
Management of Perilymphatic Leak
To manage a perilymphatic leak during cochlear implantation, several strategies can be employed:
- Sealing the cochleostomy with muscle or fat tissue to control the leak 2, 3
- Using fibrin glue applications for excessive leakage 3
- Performing a subtotal petrosectomy and obliteration of the cavity with fat tissue in cases where other methods fail 3
- Complete packing of the middle ear space in addition to the cochleostomy to control CSF leak 4
Predicting Perilymphatic Leak
Predicting perilymphatic leak is crucial in managing the condition:
- High-resolution computed tomography (HRCT) findings of cochlear malformations and bony fistula on the fundus of the internal auditory canal can indicate an abnormal connection between subarachnoid and perilymphatic spaces, increasing the risk of perilymph gusher 5
- Preoperative imaging can be predictive in only 50% of cases 4
Cochleostomy Size
The size of the cochleostomy can affect the control of perilymph fistula:
- A 1.5-mm cochleostomy is associated with a decreased risk of perilymphatic fistula compared to a 1.0-mm cochleostomy at 30 cm H2O 6
- The size of the cochleostomy may represent a phenomenon of packing adequacy 6
Intraoperative and Postoperative Management
Intraoperative and postoperative management of perilymphatic leak is critical: