Meningoencephalocele and other dural disruptions: complications of Le Fort III midfacial osteotomies and distraction.

OBJECTIVE

Complications of Le Fort III midfacial advancement include cerebrospinal fluid (CSF) rhinorrhea, meningitis, and ocular and cerebral injury. This report reviews our experience with Le Fort III distraction, highlighting complications of dural disruption, and correlates occurrences with the anatomy of the cranial base and prior cranial procedures.

METHODS

This was a retrospective chart review of all patients who had Le Fort III subcranial osteotomies and midfacial advancement with distraction. Complications related to dural disruption were documented. The anatomy of the anterior cranial fossa was assessed with preoperative computed tomographic (CT) scans and compared with age- and sex-matched normal control scans, with particular attention paid to the anterior cranial fossa and fovea ethmoidalis (FE). On reconstructed midline sagittal images, the anterior cranial fossa was characterized as normal, sagging, or slanting. On reconstructed coronal images, immediately posterior to the plane of the lacrimal sac, each FE was characterized as normal, flattened, or depressed, relative to the adjacent cribriform plates.

RESULTS

Thirty-one patients have had Le Fort III midfacial advancement with distraction at Children's Hospital Boston since 1995. Two patients underwent a second Le Fort III distraction. Two patients (6.5%) had postoperative CSF rhinorrhea, 2 had CSF leak at a pin site, and 1 patient had a late complication of meningoencephalocele. Twenty-six patients had 27 available preoperative three-dimensional reformatted CT scans. Seven of these had a normal sagittal anterior cranial fossa and normal coronal FE morphology. One of these 7 patients had a second CT at an older age showing development of bilateral FE flattening. Eleven patients had a sagging midline anterior cranial fossa including both patients who developed CSF rhinorrhea. Of these 11 patients, all had unilateral or bilateral flattening or depression of the FE, and 5 had abnormal slanting of the anterior cranial fossa. Eight patients had normal sagittal morphology, but bilateral or unilateral depression of the FE, including the patient who developed a meningoencephalocele. All patients with CSF leak had previously had a fronto-orbital advancement (FOA). Three of 4 patients with CSF leak did not have prior ventriculoperitoneal shunt placement. The patient with postoperative meningoencephalocele had prior FOA and shunt.

CONCLUSIONS

We studied the abnormal position of the sagging or slanted anterior cranial base and depressed FE in patients with syndromic coronal synostosis. These findings may explain the risk for dural tear during osteotomies at the nasofrontal suture and superior-medial orbital wall. Attention to the morphology of the anterior cranial base, as seen on sagittal and coronal CT images, aids in preventing these complications. Patients who have a shunt are at lower risk for CSF leak; however, patients who have had an FOA are at higher risk.