U-shaped durotomy for midline posterior fossa tumor removal: technical note and evaluation of results.

BACKGROUND: The classical dura opening for midline posterior fossa tumors in and around the 4th ventricle and the craniocervical junction is a Y-shaped incision. Several potential problems are associated with this technique. We used a technical variant, the U-shaped durotomy, previously described by Rhoton, offering several advantages. We report on the surgical results of the technique in a consecutive series of posterior fossa cases in children and adolescents.

METHODS: In all midline posterior fossa approaches, a U-shaped dural incision is standard in our institution. All cases were retrospectively analyzed regarding hydrocephalus, placement of EVD or lumbar drain, need for ETV or shunting during follow-up, and frequency of duraplasty, of pseudomeningocele, of primary watertight dural closure, of CSF leakage, and of venous sinus hemorrhage at opening.

RESULTS: Fifty pediatric patients were included. In all easy occipital sinus, control was achieved and no additional dural retraction for tumor exposure required. In 49/50 patients, a primary watertight dura closure without duraplasty was achieved, also in re-do cases with previous U-shaped opening. One patient received a small periostium graft after having had a duraplasty following Y-shaped opening beforehand. No CSF fistula ever occurred and no pseudomeningocele was detected in any follow-up MRI.

CONCLUSION: The U-shaped durotomy for dorsal midline approach to the 4th ventricle and craniocervical junction provides wide exposure to all tumors and allows for primary and watertight dura closure. Compared to published results and complications of classic Y-shaped dural opening, this method of durotomy and closure seems most advantageous.