RESUMO
BACKGROUND: Various methods of fixation have been described for custom made hydroxyapatite cranial implants. Their poor malleability limits most of the common used fixation techniques because of the high risk of cranioplasty's fracturing or higher exposure to infections. We present our experience with a new fixation technique, based on an appositely premodified hydroxyapatite implants. METHODS: In a 2-year time period, 12 patients underwent cranioplasty by a modified custom made porous hydroxyapatite implant. Once the three-dimensional computer model of the prostheses was performed, three semicircular extensions placed at strategic positions were drawn and the final prosthesis was realized. At surgery, holes fitting the extensions were drilled into the skull borders and the implant was easily embedded inside the defect. Small titanium meshes overlying the extensions were fixed by screws to the surrounding bone. RESULTS: A minimal increase of operative times was recorded, with drilling and fixation requiring additional 30 and 15 minutes, respectively. Optimal contact between cranioplasty and skull borders was always observed at control computed tomography (CT) scans. Permanent rigid fixation was obtained in all cases, with good functional and aesthetic results at follow-up. CONCLUSIONS: Modifications of hydroxyapatite implants are obtained without additional costs. The minimal increase of operative times is largely counterbalanced by optimal fixation results. Finally, the bone drilling and the immediate proximity of bone to prosthesis might enhance the potential for osteogenesis and osteointegration.
RESUMO
OBJECTIVE: This study describes the use of a novel collagen-based dural substitute in endoscopic endonasal transsphenoidal surgery. METHODS: Operative records were reviewed for a 12-month period for all patients who underwent surgery by means of an endoscopic endonasal transsphenoidal approach since we began using TissuDura (Baxter, Vienna, Austria) collagen-only dural substitute in January 2004. RESULTS: During the 12-month period evaluated, we performed an endoscopic endonasal transsphenoidal operation for a variety of pituitary lesions on 72 consecutive patients. Among these, 15 patients (20.8%) required the implant of the collagen foil. Nine patients (60%) presented an intraoperative CSF leak (3 small weeping of CSF and 6 larger leaks); in these cases, the TissuDura was used against the arachnoid membrane, followed by the other materials used for the repair. In 7 other subjects without any evidence of CSF escape, the collagen foil was used to protect and enforce the arachnoidal membrane descent into the sellar cavity to prevent its possible postoperative rupture and consequent CSF leak. Fibrin glue was used in all cases. A postoperative CSF leak with meningitis occurred in only 1 (6.7%) of the 15 subjects. The patient required a reoperation for CSF fistula repair and intravenous antibiotics. CONCLUSIONS: Even if based on a relatively small patient series, our experience demonstrated that the use of TissuDura in transsphenoidal surgery is safe and biocompatible, as compared with other dural substitutes.
