What's new in otolaryngology--head and neck surgery.

Abstract

The various diseases and conditions of the head and neck region involve multiple organ systems and require a wide range of medical and surgical management. So the field of otolaryngology—head and neck surgery—unites several subspecialties to address this multitude of problems. In the past year, numerous developments in both basic science and clinical science have arisen. The most exciting recent developments are discussed and grouped into subspecialties: otology and neurotology, facial plastic and reconstructive surgery, laryngology, rhinology, general otolaryngology, and pediatric otolaryngology. Head and neck oncology is given special emphasis and is discussed in a separate section because of the large volume of significant research within this field and its relevance to other surgical disciplines. OTOLARYNGOLOGY Otology/neurotology A wide variety of research studies have been conducted on inner ear and middle ear diseases as they pertain to auditory and vestibular function. The development of new technologies has provided several novel options for hearing restoration. Venerable topics such as Meniere’s disease and idiopathic facial nerve paralysis have been revisited. As research on cochlear gene therapy grows, increasing routes of delivery into the inner ear, more numerous viral and nonviral vectors, and newly discovered candidate genes are emerging for human therapy of hearing loss of inner ear origin. 1 Genetic linkage studies in several families with hereditary, nonsyndromic sensorineural hearing loss have led to the identification of numerous causative genes. An important gene implicated in the development of certain forms of hereditary deafness encodes the gap-junction protein connexin-26 (GJB2). Up to one-half of patients with autosomal recessive nonsyndromic prelingual deafness have alterations in this protein. Of note, a significant percentage of these patients have only one mutant GJB2 allele, suggesting the presence of another unidentified accompanying mutation. Del Castillo and coworkers 2 sought to identify this missing mutation through evaluation of 33 subjects with nonsyndromic hearing impairment who had only one GJB2 mutant allele. DNA analysis from peripheral blood samples identified a novel mutation that truncates a separate gene encoding for connexin 30 (GJB6) in this group of patients. This gene, located on the same locus of chromosome 13q12 as the connexin 26 gene, is now believed to be the second most frequent mutation causing prelingual deafness in the Spanish population. This report and similar reports in New Zealand subjects 3 and Jewish subjects 4 prompts further study of the role of connexins in the cochlea and provide possible targets for eventual gene therapy. The degeneration of cochlear hair cells caused by ototoxic injury leads to the reduction of neurotrophic support to the innervating auditory neurons. In another application of cochlear gene therapy, Lalwani and associates 5 showed increased inner ear neuronal survival in animals subjected to ototoxic doses of aminoglycoside. Rat cochlear explants that were transfected with an adeno-associated virus-brain derived neurotrophic factor demonstrated increased neuronal survival as compared with controls. In vivo studies using a green fluo