A larger volume cranial vault expansion is likely facilitated by a low posterior cranial osteotomy beneath the torcula; however, this may impart an increased risk of venous bleeding. The authors compared the safety of infratorcular versus supratorcular osteotomy in patients undergoing posterior vault reconstruction or posterior vault distraction osteogenesis and analyzed volumetric changes.
Patients undergoing initial posterior vault reconstruction or distraction osteogenesis between 2009 and 2021 at the authors’ institution were grouped by occipital osteotomy location and analyzed retrospectively. Craniometric analysis was performed if patients had high-resolution computed tomography scans available within 180 days preoperatively and postoperatively.
A total of 187 patients were included: 106 (57 percent) who underwent posterior vault distraction osteogenesis and 81 (43 percent) who underwent posterior vault reconstruction. Infratorcular osteotomy was more common in reconstruction [n = 65 (80 percent)] than in distraction osteogenesis [n = 61 (58 percent); p < 0.002]. Blood transfused was similar between low and high osteotomy cohorts in the distraction osteogenesis (p = 0.285) and reconstruction (p = 0.342) groups. However, median transfused blood volume per kilogram of patient weight was greater in the low versus high osteotomy distraction osteogenesis (p = 0.010) and reconstruction (p = 0.041) cohorts. Intraoperative venous sinus injury was rare. In the distraction osteogenesis cohort, there was increased median intracranial volumetric gain in the low (263 ml) compared with the high osteotomy cohort (127 ml; p = 0.043); however, when controlled for distraction distance, only a trend was observed (p = 0.221). Patients undergoing distraction osteogenesis showed a larger median intracranial volume increase (168 ml) compared with those undergoing reconstruction (73 ml; p < 0.001).
Infratorcular osteotomy can be performed safely in most patients undergoing cranial vault remodeling and does not appear to be associated with greater hemodynamic instability or sinus injury.
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