Surgical management of meningiomas originating in Meckel's cave

OBJECTIVE: To define the difference of meningiomas that originate in the area of Meckel's cave (MC) (primary MC meningiomas) in regard to the different surgical approaches and postoperative results. METHODS: A retrospective analysis of all meningiomas involving the cranial base displayed 21 cases of meningiomas originating in MC (primary MC meningiomas). These cases were classified according to the tumor extension in four different types: Type I, tumors mainly confined to MC; Type II, MC meningiomas with extension into the middle fossa; Type III, MC meningiomas with extension into the posterior fossa; and Type IV, MC meningiomas with extension into both middle and posterior fossae. RESULTS: Trigeminal neuralgia resolved in all cases in this series, despite tumor type. Trigeminal hypesthesia showed postoperative improvement only in Type III MC meningiomas. In Types I and III, total removal without further morbidity was frequently achieved. Cavernous sinus infiltration, especially in Types II and IV, limited (in some cases) the extent of tumor extirpation. CONCLUSION: Types I, II, and III MC meningiomas have a good prognosis. In most cases, very good outcomes are achieved. Radical tumor removal can usually be achieved without further morbidity and with postoperative improvement of the preexisting symptoms, especially in Types I and III MC meningiomas. On the contrary, Type IV MC meningiomas are usually only subtotally resected. Surgery in such cases may carry a high risk of additional morbidity, especially with regard to the IIIrd, IVth, and VIth cranial nerves. The postoperative outcome regarding facial pain in cases of all tumor types is usually very good. Trigeminal hypesthesia may persist after tumor removal in the majority of cases.     

Three-dimensional computed tomographic reconstruction: planning tool for surgery of skull base pathologies

Maintenance of homeostasis in the upper small bowel is a vital process for the body and therefore highly controlled. The enteric nervous system and the endocrine system are the regulators in this process influencing each other. The endocrine system in the gut consists of the classical hormones [cholecystokinin (CCK) secretin] to evoke motility or secretion. They are under control of releasing factors which are probably influenced by the enteric nervous system. Diazepam binding inhibitor and luminal CCK-releasing factor are likely candidates for CCK-releasing peptides in the negative feedback process in the absence of pancreatic juice. Experimental evidence suggests a secretin-releasing peptide. Further studies will be needed to determine the physiological role of each of these peptides. Monitor peptide in the pancreatic juice seems to function as a specific positive enhancement for CCK release. All these peptides are inactivated by the proteolytic enzymes during the interdigestive period. The discovery of additional releasing peptides and factors is very likely.     

Cationic polymerization of isobutylene by AlCl3 in n-hexane and toluene at mild temperatures

This study aims to find more efficient ways to manufacture highly reactive polyisobutylene (HRPIB) and modified conventional PIB materials (MCPIB) industrially with high vinyl exo-group contents through cationic polymerization at mild temperatures. The study performed polymerizations using aluminum trichloride (AlCl3) as a catalyst with different nonpolar solvents (hexane and toluene), reaction temperatures (10 and 30°C), and co-catalysts (water and dibutyl ether [DBE]). At 30°C, toluene can provide vinyl contents above 30 mol%. Particularly, an important synergetic effect was observed between toluene and ether, as corroborated by statistical analyses, resulting in vinyl contents above 50 mol%, while reactions performed in n-hexane provided maximum vinyl content of 20 mol%. In all cases, number average molar masses ranged from 200 to 1000 Da, which are typical of CPIB and MCPIB materials. Moreover, addition of excess of ether indicated the likely inhibition of reaction rates in presence of high ether concentrations (≥1.18 × 10 ⁻¹ mol/L). The obtained results indicated that AlCl3 can be used successfully to manufacture MCPIB products with terminal vinyl contents above 50 mol% at mild temperatures in common nonpolar solvents (n-hexane and toluene) and in presence of common co-catalysts (water and DBE) with high rates of reactions.     

Neurofibromatosis 2 in the pediatric age group

Cataract surgeons frequently face the challenge of treating an open-angle glaucoma patient presenting for cataract surgery and intraocular lens implantation. It seems logical to treat both problems during the same surgical procedure if it can be done without jeopardizing the results of either. We present a short historic overview of the trabeculotomy procedure in adults, together with our technique using the new Fukasaku modification of the instrumentation (probes and forceps) and report 50 consecutive cases with a 100% three-month follow-up. The mean preoperative intraocular pressure was 19.3 mm Hg (range 16.0 to 37.0 mm Hg); three months after surgery it was 14.2 mm Hg (range 6.0 to 24.0 mm Hg). The mean preoperative pressure-reducing medications were 2.3 drugs per patient, and the postoperative mean was 0.7. Except for three cases of small postoperative hyphemas, no other complications were encountered during the study.