Increased chromium and molybdenum blood levels after minimally-invasive repair of pectus excavatum

Objectives Minimally Invasive Repair of Pectus Excavatum (MIRPE) is the most popular technique to repair pectus excavatum in young patients. One or more metallic bars are inserted and maintained for at least 2–3 years. Few reports about possible metal release in these patients were published recently. The study aimed to search for an increase in blood metal levels in patients after MIRPE and to investigate if surgical details (number of bars and stabilizers) were correlated with metal release. Methods We have prospectively studied blood levels of chromium, nickel, molybdenum and manganese before bar implant in a group of patients undergoing MIRPE between 2017 and 2019 and, in the same patients, at the moment of bar removals between 2020 and 2022. All our patients had the same stainless-steel bar. Blood samples were analysed using inductively coupled plasma mass spectrometry. Main results We enrolled a total of 53 (10 females) patients. Median age at MIRPE was 15.4 years. After a bar maintenance median time of 3.1 years, we found significantly (p < .05) higher mean levels of chromium (2.43 versus 0.52 µg/l) and molybdenum (1.87 versus 0.35 µg/l), and higher mean levels of nickel (4.24 versus 80.80 µg/l) and manganese (12.69 versus 19.81 µg/l) without statistical significance. No differences were found regarding the number of bars, stabilizers implanted or gender. No patients had clinical symptoms of metallosis. Conclusions We demonstrated that metal blood levels increase in patients with retrosternal bars after MIRPE. Clinical implications of our finding are still unknown.