Cranioplasty following craniectomy: Clinical outcomes in adults and children

Craniectomy is commonly performed to relieve medically refractory intracranial pressure after conditions such as traumatic brain injury (TBI) and malignant cerebral infarction. As more patients survive, cranioplasty is needed to protect the brain, restore skull appearance, and support neurological recovery through improved cerebral blood flow, cerebrospinal fluid hydrodynamics, and cerebral metabolic activity. This thesis examined clinical outcomes after cranioplasty in adult and pediatric patients.

In adults, a retrospective cohort study of 182 patients identified indication for craniectomy, cranial defect size, cranioplasty implant material, and skin-closure method as predictors of cranioplasty implant survival. Craniectomy for malignant infarction or infection was associated with fewer revisions than TBI, whereas tumor-related craniectomy increased revision risk. Larger defects, autologous
bone flaps, and staple closure also increased revision risk. Autologous bone grafts had significantly more complications and revisions than cranial implants, mainly due to bone flap resorption. The prediction model showed fair performance but requires external validation before clinical use.

A prospective study of 80 cranioplasty patients and 70 controls evaluated patient-reported outcomes using the Craniofacial Surgery Outcomes Questionnaire (CSO-Q). Most patients were satisfied with their facial and skull appearance, had normal-to-high self-esteem, and reported low fear of negative evaluation. Satisfaction with head symmetry was lowest, likely because of temporal hollowing. Overall, outcomes were comparable with controls, suggesting limited
negative effects of craniectomy and cranioplasty on appearance-related quality of life.

A cost-effectiveness study of 168 adults found cranial implants to be both more effective and less costly over time than autologous bone flaps. Although initial procedure costs were similar, implants resulted in lower total healthcare costs because fewer revision surgeries were required.

Radiological evaluation of 38 patients with glass fiber-reinforced composite-bioactive glass implants showed increased skull-bone volume and density after one year. However, without a control group, the effect cannot be attributed definitively to the implant.

In pediatric cranioplasty, a systematic review of 24 studies including 864 procedures found frequent complications in both autologous bone grafts and cranial implants. Bone flap resorption was most common with autologous grafts, while infection was most common with cranial implants. A multicenter study of 64 children similarly found high resorption rates after autologous grafting; cranial implants showed lower morbidity and revision rates, although implant loosening was common.

Overall, cranial implants appear superior to autologous bone grafts in adults. In children, complications and revisions remain common across materials, and heterogeneous outcome measures prevent firm conclusions. Long-term prospective multicenter studies are needed to identify optimal implant materials and perioperative strategies.