[Retained foreign bodies from the surgical point of view]

The number of foreign bodies remaining in the patient after a surgical procedure is presumably higher than mentioned in the literature. According to US insurance statistics, the incidence amounts to 1 in 1,500 surgical procedures. As a basic principle--also from the legal aspect--it is necessary to determine whether a foreign body was left in situ accidentally (i.e. due to a material fault) or if it was simply forgotten. In 70% of cases, fabric items (e.g. swabs etc.) are left behind, while around 30% are metal objects. A particularly high risk is seen in emergency settings, in unexpected changes in the surgical procedure, or for patients with a high body mass index. The outcome for the patient differs depending on the nature of the object left behind and the individual patient's situation. Usually, metal items cause more acute clinical symptoms at an earlier time after the operation. Fabric items tend to induce, in the absence of primary contamination, a chronic progression of symptoms over several years. Reoperation has a high mortality (between 11% and 35%). Precautions in terms of risk management have to be established and need to be strictly respected, especially in high risk settings. Visually or acoustically controlled monitoring before wound-closure are recommended to eliminate "human error" as thoroughly as possible.