Implantation of Deep Brain Stimulator Through Polyetheretherketone (PEEK) Cranioplasty

Polyetheretherketone (PEEK) is a commonly used material for cranioplasties due to its advantages over other materials and autologous bone grafts. PEEK has an increased malleability, which increases postoperative aesthetics and adapts well to the cranial contours; it is also associated with a lower rate of infection when compared with autologous cranioplasties. Despite these benefits, there is limited information on the practical aspects of modifying PEEK cranioplasties after their initial placement.

We present 2 cases of patients who had previously undergone PEEK cranioplasty being treated with deep-brain stimulation (DBS), which was placed through their PEEK implant. The first was an 18-year-old male who had previously undergone cranial vault closure with bone grafts following a craniotomy. Later, when a deep-brain stimulator was planned, it was discovered that the bone grafts had significant resorption and a lack of structural integrity. Therefore, bone grafts were replaced with a custom PEEK implant cranioplasty before the DBS electrodes were placed via drilling through the PEEK implant to access the brain at a later surgery. The second patient was a 39-year-old male who developed epilepsy after a stroke, requiring craniotomy. DBS was unable to be performed initially due to significant resorption of the patient's native bone. Therefore, a PEEK cranioplasty was performed in preparation for a staged, subsequent placement of DBS electrodes through the implant. Both patients recovered uneventfully following surgery, with noticeable improvement in functional (reduction in seizure frequency) and aesthetic outcomes.

A literature review was conducted using PubMed with keywords related to PEEK cranioplasties. After screening titles, abstracts, and full-text papers, it was found that 3 previously documented cases have involved drilling through PEEK implants: one by Mallela et al, involving SEEG electrode placement; one by Marrone et al, concerning a burr hole for evacuating a chronic subdural hematoma; and one by Ledesma et al, regarding the placement of subdural grid electrodes.

This case series highlights how PEEK cranioplasties can be drilled through for therapeutic procedures, such as DBS electrode implantation, without compromising their structure. These cases illustrate the versatility, safety, and adaptability of PEEK implants for additional necessary interventions.