Long-term Outcomes of Porous Polyethylene Cranioplasty for Large Cranial Defects in Children: Assessment of Clinical Results and Cranial Growth.

ObjectiveTo examine long-term outcomes and cranial growth after porous polyethylene (PPE) cranioplasty for large calvarial defects in children.DesignRetrospective review.SettingTertiary pediatric hospital.PatientsPediatric patients from 2006-2023 who underwent custom PPE cranioplasty (Medpor, Stryker) for large calvarial defects (>75 cm2) were identified. Twenty-six of 27 patients were included. Subset analysis was performed in 12 patients with CT scans obtained more than 5 years postcranioplasty to assess cranial growth.InterventionPPE cranioplasty.Outcome measuresPresurgical characteristics and clinical outcomes. For cranial growth, intracranial volume (ICV) and head circumference (HC) were calculated using CT at two time points.ResultsTwenty-six patients (mean age = 7.9 years; range = 2.4-21.3 years) with cranial defects averaging 152 cm2 (range = 75-446 cm2) were included. The most common cause was traumatic brain injury (19 patients). Eighty-five percent had failed autologous cranioplasty, and 42% had prior infections. At last follow-up (mean = 6.5 years; range = 1.3-14.5 years), 25 patients had stable coverage and contour without complications. One patient required explantation because of iatrogenic causes. Growth analysis of 12 patients (mean follow-up = 9.3 years; range = 5.4-14.5 years) showed HC increased in all cases and remained within the same age-adjusted percentile range as pre-cranioplasty values. ICV increased or remained stable in 9 of 12 patients. In the remaining three patients, HC-ICV discrepancies resulted from inward calvarial thickening concurrent with intrinsic brain abnormalities.ConclusionsPPE cranioplasty appears to be safe for large cranial defects in select pediatric cases. Head circumference growth occurs over time and remains within normative ranges long term, whereas ICV changes do not always parallel HC. This growth pattern appears related to the extent of underlying brain injury rather than the reconstruction itself.