Prevalence of the juxtaphrenic peak after upper lobectomy

OBJECTIVE. The purpose of this study was to determine the prevalence of the juxtaphrenic peak after upper lobectomy in a large number of consecutive p atients. MATERIALS AND METHODS. Available chest radiographs of 172 of 199 sequential patients; who had undergone upper lobectomy in a university hospital were evaluated for the presence of a juxtaphrenic. peak. The study included 98 c ases with right upper lobectomy and 74 with left upper lobectomy. Radiograp hs were grouped in three postoperative periods: period I, within 7 days aft er lobectomy (n = 142); period II, between 8 and 30 days (n = 113); and per iod III, 31 days or more after lobectomy (n = 101). Four experienced radiol ogists in consensus determined the prevalence of the "juxtaphrenic peak sig n," in relation to age, sex, side of lobectomy, positioning (erect or supin e), presence of juxtadiaphragmatic abnormalities, and time interval since s urgery. RESULTS. The prevalence of the juxtaphrenic peak sign gradually increased f rom 40.6% in period I to 71.9% in period III after right upper lobectomy (p < 0.01), and from 19% to 47.7%, respectively, after left upper lobectomy ( p < 0.01). Its overall prevalence was significantly higher after right uppe r lobectomy (58.2%) than after left upper lobectomy (40.5%) (p = 0.02), and on erect chest films (51.4%) than on supine ones (28.9%). CONCLUSION. The prevalence of the juxtaphrenic peak sign increases graduall y during the weeks following lobectomy. It is more frequent on erect films and after right upper lobectorny. The juxtaphrenic peak may serve as an add itional useful radiologic sign suggesting upper lobectorny.