No abstract

For acoustic neuroma excision, higher-volume hospitals and surgeons provided superior short-term outcomes with shorter lengths of stay and lower charges.

Objective/Hypothesis: To determine if angiogenic growth factors including vascular endothelial growth factor (VEGF) and platelet‐derived endothelial cell growth factor (PD‐ECGF) are expressed in human paragangliomas. Study Design: A histopathologic and molecular examination of paraganglioma specimens obtained from surgical cases or retrieved from the Pathology Department of the Massachusetts Eye and Ear Infirmary. Methods: Fresh tumor or archival, paraffin‐embedded paraganglioma specimens were analyzed by immunohistochemistry, Western blotting, and ELISA. Results: Positive immunohistochemical staining for VEGF was observed in five of nine surgical specimens and in six of eight archival specimens (11/17, or 65%). PD‐ECGF immunoreactivity was detected in four of five surgical specimens and six of eight archival specimens (10/13, or 77%). The presence of PD‐ECGF was confirmed by Western blot assay and ELISA confirmed the presence of VEGF in tumor extract. Conclusions: Both VEGF and PD‐ECGF are expressed in paragangliomas and may contribute to the extreme vascularity of these tumors.

A reliable objective test for estimating the number and distribution of surviving eighth nerve fibers needs to be identified for selection of candidates for cochlear implantation. Kanamycin and ethacrynic acid administration in guinea pigs resulted in graded amounts of eighth nerve degeneration over time. The electrically-induced middle latency response (EMLR) was acutely recorded in these animals at specific post-drug times, followed by the immediate killing of the animals, histologic preparation, and spiral ganglion cell density determination. Significant progressive spiral ganglion cell loss was noted by 4 weeks that increased over time. While EMLR threshold remained stable over time, the slope of the EMLR input/output function decreased with increasing post-drug intervals in a manner directly correlated with reduction in spiral ganglion cell density.