Keefer K M, Johnson R
U.S. Air Force School of Aerospace Medicine, Brooks Air Force Base, TX 31098-2227, USA.
Aviat Space Environ Med. 1995 Oct;66(10):1001-4.
USAF aviators may be granted medical waivers for continued flying duties when diagnosed as having retained renal calculi in parenchymal locations or in portions of the collecting system from which spontaneous passage is unlikely. The USAF Aircrew Medical Waiver File was reviewed in order to determine the proportion of USAF aviators with waivers for retained renal calculi whose calculi subsequently resolved. Of the 60 currently active aviators granted waivers between January 1976 and December 1990, 7 have had their retained calculi resolve following surgical intervention, and 13 (21.7%), 95% CI [11.2%, 32.1%], had "spontaneous" resolution of their retained calculi. Using the Armstrong Laboratory's Aeromedical Consultation Service clinical database, it was possible to determine how the diagnoses of retained stones were established and/or disestablished in 15 of the 60 aviators. Theories on stone formation and resolution, tools employed in diagnosis, and implications of these study findings on flight duties are discussed.