Displacement of the bar after minimally-invasive repair of pectus excavatum

The most common complication of the minimally-invasive technique for the repair of pectus excavatum is displacement of the bar, and it may cause retraction of the chest. We aimed to find out if there was any factor that could predict displacement of the bar after operation. The records of 12 patients who were operated on for repair of pectus excavatum at the Osaka Medical College between December 1999 and August 2006 were analysed. Their mean age was 9 years (range 4-21). The mean Haller computed tomographic (CT) index was 4.9 (range 3.8-6.9). To predict the risk of postoperative rotation of the bar we considered patients' age, Haller CT index, intercostal distance where the pectus bar passed through, and the depression index. The bar was displaced in four patients, and there was a significant difference in depression index between those in whom the bar was displaced (n=4) and those in whom it was not (n=8). In the displacement group, it ranged from 25% to 38% (mean 32%), and in the undisplaced group from 15% to 27% (mean 18%). There was a significant difference between the groups (p<0.01). Rotation of the bar is thought to be closely related to its stability at the deepest point of the depressed sternum. The depression index is useful in predicting the risk of rotation of the bar.