Exchange Cranioplasty Using Autologous Calvarial Particulate Bone Graft Effectively Repairs Large Cranial Defects

Autogenous particulate cranial bone graft has been proven to be effective for inlay cranioplasty but does not provide structural contour. This limitation can be overcome using an exchange cranioplasty technique. This study probes the effectiveness of this method for large (>5 cm(2)) or complicated cranial defects. The authors conducted a retrospective review of patients managed with autologous exchange cranioplasty between 2005 and 2010. Full-thickness calvarial bone was removed from the intact cranium; particulate bone graft was harvested from the graft endocortex or ectocortex of intact cranium. The original defect was repaired with the full-thickness graft and the donor site was covered with particulate graft. Patient records were reviewed for age at cranioplasty, operative indication, size and location of defect, operative time, blood loss, and length of follow-up. Outcome variables included complications, osseous defects, and need for revision cranioplasty. Twenty patients underwent exchange cranioplasty at a mean age of 8.3 ± 6.2 years. Average values for the group included length of procedure, 4.7 hours; estimated blood loss, 288 ml; hospital stay, 3.1 days; and follow-up, 1.57 years (range, 24 weeks to 3.7 years). Eighty-five percent of patients underwent postoperative computed tomographic scanning to document healing. Fifteen patients had complete healing; five patients had residual bone defects (four by computed tomography and palpation, and one by computed tomography only). The cranial defect area decreased 96 percent on average from a preoperative mean of 85.2 cm(2) to a postoperative combined defect size (donor plus recipient) of 3.3 cm(2). Autologous exchange cranioplasty using particulate bone graft is safe and highly effective for reconstructing even large cranial defects.