Outcomes of canalplasty for chronic obliterative otitis externa.

INTRODUCTION: Chronic obliterative otitis externa is a rare cause of conductive hearing loss, characterised by stenosis of the deep ear canal secondary to chronic inflammation. A multitude of canalplasty techniques have been described, with variable success. METHOD: Fourteen patients undergoing canalplasty performed by the senior author for refractory obliterative otitis externa, over an 8-year period, were included in the study. All underwent split-skin grafting of the denuded canal and meticulous post-operative aural care. Outcome measures included the Glasgow Benefit Inventory and pure tone audiology. RESULTS: At 3 months post-operatively, the four-tone average threshold had improved by a mean of 13.9 dB (95 per cent confidence interval -9.9 to 37.8 dB; t < 0.001) in the operated ear. The mean Glasgow Benefit Inventory score was 20 (95 per cent confidence interval -2.3 to 42.1). CONCLUSION: Significant improvements in both hearing and quality of life are achievable in patients with end-stage obliterative otitis externa treated surgically. Highly trained and competent aural care practitioners are a prerequisite for the success of the procedure, and a substantial number of patients must be prepared to submit to long-term follow-up care.

Diagnostic, prognostic and therapeutic implications of carbonic anhydrases in cancer.

The carbonic anhydrases (CAs) comprise a family of evolutionarily ancient enzymes found ubiquitously in nature. They have important roles in facilitating transport of carbon dioxide and protons in the intracellular space, across biological membranes and in the unstirred layers of the extracellular space. The tumour-associated isoenzymes, CAIX and CAXII, are expressed in a wide variety of malignancies and appear to be tightly regulated by microenvironmental hypoxia. CAIX expression is linked to poor prognosis in a number of human tumours, and may be a marker of aggressive malignant phenotype and a mechanism of progression. Inhibitors of CA may inhibit tumour growth and invasion, with consequent therapeutic potential.