Lessons learned in posterior cranial vault distraction

Posterior distraction (PD) is rapidly emerging as an important technique to increase the intracranial volume and correct calvarial morphology in patients with severe brachycephaly or turribrachycephaly. A retrospective review was performed of all 31 patients who underwent PD at the Oxford Craniofacial Unit between 2007 and 2012. Twenty-three patients (74.2%) underwent PD as a primary procedure at a median age of 8 months. Eight patients (25.8%) had PD as a secondary transcranial procedure at a median age of 48 months. Full distraction to 20 mm was achieved in 28 patients (90.3%). Of these, all but 1 demonstrated a significant improvement in morphology, with a resolution of the symptoms and signs of raised intracranial pressure in all proven to have it preoperatively. Unanticipated events occurred in 61.3% of patients, with 19.4% undergoing one or more unplanned procedures. Wound infection (29.0%) and tissue necrosis (22.6%) were the commonest. Cerebrospinal fluid leaks were rarer (6.5%) but prevented full distraction. Nine patients (29.0%) had a consolidation period of less than 30 days without experiencing relapse. In 11 patients who had a later fronto-orbital advancement and remodeling, wound closure was tight, resulting in dehiscence in 3 cases (27.3%). Posterior distraction is an effective procedure in the management of severe brachycephaly or turribrachycephaly but has associated risks. Our protocol has evolved with experience to favor a reduced latency period and consolidation phase and the use of 2 distractor devices.