Early detection of viable microorganisms in "sterile" periprosthetic fluids in implant-based breast reconstruction: A bioelectrochemical approach using screen-printed electrodes

Background: Early postoperative infections are an important complication after postmastectomy implant-based breast reconstruction with current diagnostic methods requiring long processing times and potentially yielding false negatives, particularly after prior antibiotic exposure. We aimed to evaluate the feasibility and diagnostic accuracy of a bioelectrochemical method, based on electrochemical impedance spectroscopy (EIS), for the early detection of viable bacteria in periprosthetic fluid following implant-based reconstruction. Methods: A total of 47 patients undergoing immediate implant-based breast reconstruction were prospectively enrolled. Periprosthetic fluid samples were collected from the drainage tube at postoperative days 7 and/or 14 (107 samples in total). Each sample was analyzed using 3 diagnostic platforms: (1) EIS, (2) molecular diagnostics, and (3) conventional microbiology. The EIS signal (Z ') was interpreted against a cut-off calibrated using gram-positive and gram-negative reference suspensions. Results: Infection was confirmed in 8 out of 47 patients (17.0%). EIS correctly identified all infected cases, showing full concordance with culture and molecular results. The technique distinguished gram-positive (Z ' 6000-20,000 Ohms) from gram-negative infections (Z ' 21,000-35,000 Ohms). The analytical time for EIS was approximately 9 min. Among positive patients, gram-positive infections were mostly asymptomatic or mild, whereas gram-negative infections were associated with severe clinical outcomes, including explantation. Conclusion: EIS offers a rapid, low-cost, and easy-to-use method for detecting bacterial presence in periprosthetic fluids. Unlike standard microbiological or molecular tests, it does not require bacterial growth, sample preparation, or nucleic acid extraction. With further validation, it has strong potential to support earlier, more tailored interventions. (c) 2025 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights are reserved, including those for text and data mining, AI training, and similar technologies.