Innovative Approach to Skull Restoration Reduces Harm to Brain

The time lag between removal and replacement often results in the scalp adhering to the outer layer of the brain; when peeling back the scalp in preparation for secondary reconstruction, the patient is often at risk of bleeding, seizure, stroke, and infection. In some cases, the replaced bone or implant must again be removed.

The new approach, called pericranial-onlay cranioplasty, involves pulling back only the top three layers of the five-layer scalp, thereby enabling the sandwiching the bone or implant in between the layers. The researchers say this innovation not only prevents brain injury, but also reduces infection risk by providing the delicate bone or implant access to blood supply in the scalp from both the top and the bottom layers.

In the study, the researchers reviewed 50 consecutive patients, encompassing 46 cranioplasties using the pericranial-onlay approach, along with 4 isolated temporal soft tissue reconstructions with liquid polymethyl methacrylate (PMMA). Of the 46 cranioplasties, only one autologous bone flap developed deep infection necessitating bone flap removal. None of the alloplastic custom implants has developed any infection requiring removal to date. The study describing the new technique was published on January 24, 2014, in the Journal of Neurosurgery.

“Everyone has been taught for 120 years to completely peel up the scalp,” said lead author craniofacial surgeon Chad Gordon, DO, an assistant professor of plastic and reconstructive surgery at JHU. “But by not disturbing the brain, we get much better outcomes. This is a safer, simpler way to do a very complex surgery.”

Ideally, surgeons restore the skull in the secondary cranial reconstruction procedure using with the same piece of bone removed during the original operation, which is stored in a freezer between operations. In some cases, surgeons must substitute the original bone with a custom-made implant made of PMMA, which has been used safely since the 1960s.

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