A new surgical technique for replacing excised skull bone protects the exposed brain far better than the old method, a risky approach that has changed little since the 1890s, surgeons say.
The new approach, described online in the journal Neurosurgery, involves peeling back only the top three layers of the five-layer scalp, then sandwiching the original bone or a replacement implant between the separated layers.
“Everyone has been taught for 120 years to completely peel up the scalp,” says study leader Chad R. Gordon, a craniofacial surgeon and assistant professor of plastic and reconstructive surgery at the Johns Hopkins University School of Medicine. “But by not disturbing the brain, we get much better outcomes. This is a safer, simpler way to do a very complex surgery.”
Patients who have skull removed to accommodate a swelling brain caused by brain injury, infection, tumor, or stroke typically undergo a second operation—a cranioplasty—a few months later to restore the protective covering. In the intervening weeks, the scalp often adheres to the outer layer of the brain.
Lower risk of infection
Traditionally, surgeons have peeled the scalp off the brain to then tuck the skull bone or custom implant back into place, a practice that puts the patient at risk of bleeding, seizure, stroke, and infection. In some cases, the replaced bone or implant must again be removed.
The new method 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, the researchers say.
“This represents a tremendous advantage for our patients,” says neurosurgeon Judy Huang, a co-author of the study.
The research team treated 50 patients using the new technique between July 2011 and June 2013. Only one patient developed a deep infection requiring bone removal. Deep infection remains the leading major complication following standard secondary cranioplasty, with rates reported between 21 and 40 percent. Blood loss also was dramatically reduced, the researchers say.
Ideally, surgeons restore the skull 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 for the original bone with a custom-made implant made of an organic compound called methyl methacrylate, which has been used safely since the 1960s.
Source: Johns Hopkins University