Outcomes and Workflow in a Titanium Powder Bed Fusion Cranial Reparation Surgery Service

Cranial reconstruction, cranioplasty, is conducted to repair skull defects caused by craniectomy following traumatic brain injury, stroke, or postoperative infection. Complications requiring implant removal occur in 10-20% of cases as the optimal cranioplasty material is not known. We describe the Cambridge University Hospital's (CUH) multidisciplinary cranial reparation service and aim to assess the safety of the workflow compared with existing technologies. We retrospectively analyzed the medical records of all patients who underwent cranioplasty via the CUH cranioplasty pathway with cranioplasty implants manufactured utilizing grade 23 Ti-6Al-4V powder bed fusion (PBF) between December 2017 and December 2021. The primary and secondary outcomes were implant removal and the occurrence of cranioplasty infections, respectively. We identified 107 cranioplasty procedures performed in 105 patients, who were followed for a median time of 34.9 months (interquartile range 46.7-17.7, range 2 days to 60.2 months). Twenty-four (22%) patients had at least one complication, and 11 (10%) cranioplasties had been removed because of complications. Thirteen (12%) patients had surgical site infections, but only eight (7%) cranioplasties had to be removed because of infections. Placement of a cerebrospinal fluid shunt (hazard ratio [HR] 8.57, 95% confidence interval [CI] 2.36-31.12) and high American Society of Anesthesiologists grade (HR 6.87, 95% CI 1.66-28.39) predicted shorter cranioplasty survival. We demonstrated the largest currently published series of titanium cranioplasties produced using PBF-the overall complication and removal rates (22% and 10%, respectively) were comparable with those reported in the literature. We have embedded the key steps and skills in the cranioplasty process in an academic setting allowing for tailored surgery and flexibility to develop further service innovations in the future. Patients with cerebrospinal fluid shunts and those in poor general condition were at increased risk of infections and subsequent cranioplasty failure.