Management of Iatrogenic Skull Base Defects

Abstract

From 1995 to 2007 at our institutions, we performed endoscopic skull base defects repair on 202 patients. Our purpose was to carry out treatment of this infirmity by using an innovative minimally invasive technique instead of open surgical procedures with avoidance of facial incision, frontal lobe retraction, removal of craniofacial skeletal components, and lumbar drainage. Reduced postoperative pain, hospital stay, and unsightly surgical scars is the goal of endoscopic surgery. We wanted therefore to refine instrumentation and operative technique, establish clear inclusion criteria, and develop a long-term success rate using standard procedures in this field still experienced in just a few leading centers. Endonasal cranioplasty found that cerebrospinal fluid leakage (CSFL) from the anterior and middle cranial fossa was mostly located to the olfactory groove (34%), followed by the ethmoidal roof (22%), sphenoclival region (19%), multiple sites (13%), and the frontal sinus wall (10%). The greatest amounts have proved to be spontaneous (n = 87; 43%), from complication of surgical procedure (n = 59; 29%), or following trauma (n = 56; 27%). Iatrogenic skull base defects have their own peculiarity and might represent troublesome treatment for both neurosurgeon and rhinologist; the transcranial approach is often advocated with a need for flap reconstruction. In our series we have successfully treated skull base lesions due to previous neurosurgical (n = 25; 12%) and rhinological (n = 34; 16%) operation, the most purely with an endoscopic-endonasal technique (n = 53; 89%) or a combined endoscopic and transcranial (n = 6; 10%) approach. Different autologous grafts and synthetic dura substitutes have been put in place to fill single or multiple defects located at the anterior and middle skull base. Grafting material has been chiefly harvested from the nasal cavity with no need for external skin incisions; otherwise fascia lata was taken from the abdomen or thigh. Patients' complaints at admission included cerebrospinal fluid rhinorrhea (84%), headache (13%), pneumoencephalus (11%), and recurrent meningitis (26%). All patients quit CSFL and resolved pneumoencephalus, and 3 patients presented with recurrence of rhinoliquorrhea and underwent adjunctive surgery with complete recovery. All patients are free from disease at the moment after a follow-up ranging from 135 to 2 months. The endoscopic-endonasal cranioplasty approach has proved to be safe and effective, largely replacing open surgery even with more complex skull base defects such as those following previous operations.