Nickel contamination after minimally-invasive repair of pectus excavatum persists after bar removal.

Background: Minimally-invasive repair of pectus excavatum (MIRPE) has been shown to be associated with high release of trace metals into patient's body. The aim of our study was to analyze the kinetics of metal contamination after MIRPE and after bar removal.
Methods: We prospectively assessed nickel and chromium changes in blood, urine, and local tissue in patients undergoing MIRPE with stainless-steel bar(s). Baseline samples were taken prior to surgery, further samples were taken at six defined time points until 30 months after bar removal. Clinical symptoms were evaluated at the time of every sample collection.
Results: 28 patients were included (mean age 16.4 years). At four weeks after MIRPE and persisting up to bar removal, we found significantly elevated trace metal levels in blood and urine. Tissue nickel and chromium levels were significantly elevated at the time of bar removal. After bar removal, the concentration of trace metal in urine and the concentration of chromium in plasma decreased gradually. In contrast, nickel levels in blood further increased. Five patients showed irritative symptoms after MIRPE, all symptomatic patients had elevated metal levels.
Conclusions: Following MIRPE, we found a rapid systemic increase of nickel and chromium. Our data indicate that trace metal release could cause irritative symptoms. The prolonged elevated systemic nickel levels beyond bar removal necessitate further investigations of the long-term side effects of MIRPE.
Competing Interests: I have read the journal’s policy and the authors of this manuscript have the following competing interests: C. Fortmann and C. Petersen are executive board members of the Chestwall International Group. C. Petersen is a consultant for MedXpert. T. Göen is a member of the DFG Senate Commission for Investigation of Health Hazards of Chemical Compounds in the Work Area and chairs the working group Biomonitoring. The remaining authors have no disclosures. The stated competing interests does not alter our adherence to PLOS ONE policies on sharing data and materials.