Original ArticleLow Incidence of Bone Flap Resorption After Native Bone Cranioplasty in Adults
Introduction
Cranioplasty is performed for protective, cosmetic, and therapeutic reasons in surviving patients who have undergone craniectomy previously for the management of space-occupying intracranial pathologies, including intracerebral hemorrhage (ICH), subarachnoid hemorrhage (SAH), traumatic brain injury, malignant cerebral edema after acute ischemic stroke, or various brain tumors and intracranial infections.1, 2, 3 Several materials can be used to repair the cranial defect. The traditional and most commonly used method is autologous bone graft with reinsertion of the native bone flap. This method is especially preferred in pediatric patients because of the potential reintegration of the flap as the patient grows up without introducing other foreign materials. Other materials that can be used to repair the defect include polymethyl methacrylate, hydroxyapatite cement, titanium mesh, or metal plates.4
Cranioplasty is associated with an important rate of complications, up to 34%.5 The main complications include infection, postoperative hematoma formation, hydrocephalus, seizures, and bone resorption.6, 7 Bone resorption remains a matter of concern in patients with native bone cranioplasty because it may result in cosmetic flaws and increased risk of brain injury and may require reoperation and replacement of the flap with other materials. The rate of bone resorption after native cranioplasty has been reported to be as low as 2% and as high as 32% in adult patients8, 9 and even greater in pediatric patients after autologous cranioplasty.10, 11, 12 Several factors pertaining to the cranioplasty procedure, such as the condition of the native bone flap, storage techniques, time to reinsertion of the bone flap, and patient characteristics, have been reported to influence the rate of bone resorption. The aim of this study is to evaluate the rate of bone flap resorption in an adult population and review associated factors that may increase the risk of this event in patients with native bone cranioplasty.
Section snippets
Patient Selection
The study protocol was approved by the University Institutional Review Board. This is a single-center retrospective cohort study that assessed consecutive patients who had a cranioplasty procedure in which their native bone flap was used, performed by the neurovascular department during a 10-year period. Adult patients (>18 years of age) who underwent cranioplasty after craniectomy for increased intracranial pressure as the result of SAH, ischemic stroke, intraparenchymal hemorrhage,
Results
In the 114 patients identified, the mean age at the time of cranioplasty was 51.2 years (Table 1); 53% of patients were women and 47% were men. A total of 41.2% of patients were smokers, 16.7% had a history of diabetes mellitus, and 60.5% of patients had a history of hypertension. The indications for the initial craniectomy procedure were SAH in 57 patients (50.9%), ICH in 20 patients (17.6%), ischemic stroke in 17 patients (14.9%), trauma in 15 patients (13.2%), subdural hematoma in 2 patients
Discussion
Bone flap resorption has been established as an important long-term complication after native bone cranioplasty.3 The reported rates of resorption after autologous cranioplasty have varied greatly. In the adult population, the incidence of bone flap resorption has ranged from 2% to as high as 32%.3, 5, 8, 9, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23 Studies involving pediatric patients have reported even greater rates of bone flap resorption, from 29% to 50%,10, 11, 24 and up to 81.8% in 1
Conclusions
The rate of autologous bone flap resorption in adult patients undergoing cranioplasty after craniectomy for SAH, ICH, ischemic stroke, and trauma is low. Our results further show that the risk of resorption is low in cryopreserved bone flaps and the risk is still low after a mean interval for cranioplasty of 6 months. When native bone flap resorption occurs, it usually presents within the first 2 years. Important factors that have been associated with the occurrence of bone flap resorption
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Bone Flap Resorption After Cranioplasty: Risk Factors and Proposal of the Flap Integrity Score
2024, World NeurosurgeryRisk factors for the development of seizures after cranioplasty in patients that sustained traumatic brain injury: A systematic review
2019, SeizureCitation Excerpt :In this group, an increasingly common surgical management option is decompressive craniectomy (DC), involving the removal of a bone flap to allow the brain to swell while relieving ICP [3,4]. The removed flap may be stored in an abdominal pouch or a specialised refrigeration unit, or discarded depending on factors such as infection and surgeon preference [5,6]. After acute swelling of the brain resolves, cranioplasty is performed to restore the integrity of the skull and cerebrospinal fluid dynamics [7].
Conflict of interest statement: The authors declare that the content of this article was composed in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.