Eventration of the diaphragm.

Eventration of the diaphragm was formerly considered very rare. The condition does not occur as often as hernia of the diaphragm, but thoracic departments come across several cases yearly. Until 1954 more than 300 cases had been published, but only a few operated on (Laxdal, McDougall, and Mellin, 1954). In the Southampton and Portsmouth mass radiography study only 32 cases of eventration were found during five years of examinations comprising 412,000 persons (Chin and Lynn, 1956). Statistics are also available from the mass radiography units of the county of Vejle, Denmark (Slottved, 1958). In 1950-1 and in 1953 a total of 107,778 persons was examined after a general invitation to the population of the county, and 38 cases were found, i.e., the frequency was four times as great as in the above-mentioned study from England. In 1950 the population of the county of Vejle was 201,041. The first case of eventration was described by Petit, published in 1774 in a posthumous edition of his work. Korns (1921) and later on Reed and Borden (1935) collected all cases and critically reviewed the literature until 1921 and 1935 respectively. Only two cases have so far been published in Denmark (Ottosen, 1924; Andersen, 1954). DEFINITION