A magnetic resonance imaging investigation of potential subclinical complications after in situ cranial bone graft harvest.

Abstract

The in situ harvest of cranial bone grafts, when assessed by clinical observation, has been shown to be a safe procedure when performed by experienced surgeons. However, might there be adverse sequelae from bone graft harvest that are not severe enough to produce observable changes and thus are missed by studies that rely on clinical outcomes? This study was designed to determine the incidence of "clinically silent" complications following routine bone graft harvest, such as punctate intracranial bleeding and cerebral contusions. This prospective clinical study included 20 patients. All patients had in situ cranial bone graft harvest performed by a single surgeon and underwent postharvest magnetic resonance imaging within 24 hours. Coronal computed tomographic scans were found to be the most helpful in the preoperative determination of donor sites. The average area of bone graft harvest was just under 14 cm2 (range, 3 to 30 cm2). No patients who had not previously undergone skull surgery were noted to have full-thickness breaches. Three patients identified with full-thickness breaches at surgery had harvest sites located in areas in which a previous craniotomy had occurred, suggesting that extreme care be used when harvesting bone from this subset of patients. All 20 postoperative magnetic resonance scans were reviewed by a neuroradiologist and determined to be completely normal. In conclusion, not only is in situ cranial bone graft harvest a safe procedure as assessed by clinical outcomes, but no subclinical complications were identified by post-operative magnetic resonance imaging.