Objective: Obstruction of the internal thoracic arteries (ITAs) bythe Nuss bars in minimally invasive repair of pectus excavatum(MIRPE) has been documented in the literature. In this study, weaim to investigate the patency of ITAs before and after repair of thepectus excavatum with the Nuss procedure, by using color Dopplerultrasonography (US).Materials and Methods: Nineteen patients who underwentNuss procedure were included in this study prospectively. ColorDoppler US examinations were performed for comparing ITApatency after insertion of the Nuss bars and after their removal.Patients were evaluated according to gender, age, symmetry ofdeformity, Haller index, and the number of Nuss bars inserted.Results: Nineteen patients operated with MIRPE (17 male and2 females with a mean age 21.78±6.35) were enrolled in the study.Eight patients (42.1%) with normal ITA blood flow preoperativelyhad normal blood flow after removal of the bar. In preoperativeexamination, 6 patients had bilateral (n=2) or unilateral (n=4)obstruction of the ITA and 5 patients had bilateral (n=2) orunilateral (n=3) abnormally disturbed flow. After the bar removalonly 2 (10%) of the affected patients (57.9 %) still had obstructionwhereas patent blood flow of the ITAs has been noted in 9 patients.Conclusion: We have shown that after the Nuss bar removal,only 10% of the ITAs are compromised