Anatomy of the Frontal Sinus Drainage Pathway Evaluated in 247 Cadavers to Prevent Cerebrospinal Fluid Leakage After Frontobasal Craniotomy.

BACKGROUND AND OBJECTIVES: The frontal sinus (FS) drainage pathway (FSDP) may be a conduit for cerebrospinal fluid leakage after frontobasal craniotomy. In this cadaveric study, we aimed to evaluate the anatomy of the FSDP. METHODS: The FSs and FSDPs of 247 cadavers were investigated. We counted the number of FSs and FSDPs in each half-head, verified the presence of a narrowing section in each FSDP, and evaluated the depth, shape, and size of each narrowing FSDP section. RESULTS: We investigated 494 sides and 472 FSDPs of 247 cadavers. FSs were unilaterally undeveloped in 13 of 247 cadavers (5.3%) and bilaterally in 8 (3.2%). FSs were unilaterally duplicated in 7 of 247 cadavers (2.8%), and no FSs were bilaterally duplicated or triplicated. No FSs had 2 or more FSDPs, and all 472 investigated FSDPs were invariably narrowed at various depths. The narrowing FSDP sections were elliptical (78.6%), circular (18.1%), triangular (1.8%), or crescent-shaped (1.4%) and of varying thickness and orientation. Although FSDPs were asymmetric in 92.2% of cadavers and narrowing FSDP sections were located deep (8.9 ± 4.4 mm from the anterior skull base), the narrowing FSDP sections were typically small (area: 5.9 ± 3.3 mm 2 ) or thin (short diameter: 2.1 ± 0.7 mm). CONCLUSION: Each FS had only one FSDP, all FSDPs were invariably narrowed at various depths, and the narrowing FSDP sections were sufficiently small or thin to allow local closure, facilitating prevention of cerebrospinal fluid leakage after frontobasal craniotomy.

Persistent Severe Cerebral Edema with Neutrophil Infiltration Following Listeria Meningitis.

A 51-year-old man was admitted to the hospital with a diagnosis of Listeria monocytogenes meningitis. Diffuse cerebral edema appeared after improvement of meningitis with appropriate treatment and worsened for two months. Due to brain herniation, brain tissue leaked through the incision made during the drain insertion in a hydrocephalus surgery. We found pathological evidence of significant neutrophil infiltration with a few lymphocytes without bacterial detection in the degraded brain tissue. The present case indicates that fatal cerebral edema with significant neutrophil infiltration may develop even after appropriate treatment for L. monocytogenes meningitis.

[Optic Neuropathy Secondary to Compression by the Internal Carotid Artery Concomitant with an Inflammatory Granuloma:A Case Report].

A 77-year-old man presented with a 6-month history of progressive right optic neuropathy secondary to compression by the ipsilateral internal carotid artery(ICA). We performed anterior clinoidectomy and optic canal unroofing. Subsequently, we wrapped the ICA with a polytetrafluoroethylene tape, pulled the vessel laterally, and sutured the tape to the dura mater at the anterior skull base for optimal decompression. An inflammatory mass lesion was observed around the ICA, which led to further compression of the optic nerve. Histopathological examination of the resected specimen showed an inflammatory granuloma. The patient's visual field deficit showed partial improvement postoperatively. Transposition using a tape might be an effective surgical alternative for compressive optic neuropathy.