Survival times of Provox valves.

This study was performed to assess the survival times of the Provox valve in the Manchester area. Thirty-nine patients from four hospitals, representing 81 valve failures, were studied. The effects of the timing of the tracheo-oesophageal puncture, previous radiotherapy, and the presence and timing of cricopharyngeal myotomy on valve life were analysed. Regression analysis using an extension of the Cox model to allow strata showed that the lifetime of the first valve only is adversely affected by previous radiotherapy. The other covariates do not have a statistically significant effect on valve survival. The median valve survival is 4.5 months, (range one to 12 months). A small percentage of valve users with particularly frequent valve failures may require additional support and prolonged anti-fungal therapy.