Wandering wires: Frequency of sternal wire abnormalities in patients with sternal dehiscence

OBJECTIVE. The purpose of this study is to assess the frequency of various sternal wire abnormalities on chest radiographs of patients with sternal dehiscence and to determine the role of radiography in detecting or confirming this complication. MATERIALS AND METHODS. We used our computerized hospital information system to identify all patients with a diagnosis of sternal dehiscence from January 1993 through June 1998, Clinical data were obtained by retrospective chart review. A chest radiograph from the date of diagnosis was compared with the first postoperative radiograph obtained after median sternotomy. Each radiograph was retrospectively reviewed by two radiologists who assessed three sternotomy wire abnormalities: displacement (offset of one or more wires in relation to others in the vertical row), rotation (alteration in the axis of a wire compared with its orientation on a baseline radiograph), and disruption (unraveling or fracture of a wire). We also reviewed a series of postoperative radiographs in a group of matched controls who had an uneventful postoperative course with no clinical evidence of dehiscence. RESULTS. The study cohort included 19 patients, 13 men and six women, who were 49-84 years old (mean, 66 years). The chest radiographs revealed sternal wire abnormalities in 17 (89%) of 19 patients with sternal dehiscence, including displacement in 16 (84%) of 19 patients, rotation in 10 (53%) of 19 patients, and disruption in four (21%) of 19 patients. The mean number of displaced wires per patient was 2.3 (range, 1-5), The mean distance of maximal displacement was 20 mm (range, 6-45 mm). Radiographic abnormalities preceded the clinical diagnosis in 13 (68%) of 19 patients. We observed no case of sternal wire displacement, rotation, or disruption in the control group. CONCLUSION. Sternal wire abnormalities, most notably displacement, are present in most patients with sternal dehiscence; radiographic abnormalities precede the clinical diagnosis in most cases.