Novel method for foreign body removal by entry needle under ultrasound

Abstract

Learning Objectives: To describe a novel percutaneous method for removing a linear metallic foreign body (FB) with an entry needle under ultrasound guidance. Background: Retained soft tissue FBs can lead to complications including pain, infection, granuloma formation, toxic or allergic reactions, patient anxiety or migration1. Foreign body removal has traditionally been performed by the bed-side either using a blind technique, usually with only plain film localisation pre-procedure2,3, or with ultrasound guidance1,4,5. However, removal can prove quite difficult and often requires a large incision2-4. Alternatively, they may be removed surgically, often in the operating theatre with the use of intraoperative imaging to locate the lesion1,2. This method is considered invasive, costly, time-consuming, technically challenging and can result in increased pain, scarring, infection and potential damage to surrounding structures1,2. In this paper we describe the use of a minimally invasive ultrasound guided technique. Procedure Details: An11mmlinear metallic foreign body was identified on X-ray within the patient's heel. Real-time ultrasound guidance was used to localise the FB and determine the entry point and trajectory. The patient was positioned and prepared using aseptic technique and 2ml of 1% lignocaine was administered around the FB. Under ultrasound guidance a 16 gauge needle is positioned in line with the FB and is slowly inserted until the entire FB is completely within the needle. The entry needle is turned and tilted slightly, then carefully withdrawn, along with the FB. ACT scan was then performed to confirm complete removal of the FB. The patient was immediately discharged with minimal pain or bleeding and nil sutures required. The procedure took a total of 10 minutes. Conclusion: Ultrasound guided percutaneous FB removal by entry needle is a promising technique that has many potential advantages over conventional techniques. It can be performed under local anesthetic, is quick and cheaper than surgical options. It only involves an entry needle and not a large incision or sutures and, hence, there is minimal risk of scar tissue formation and earlier post-procedure healing. However this technique does require that the FB easily fit into a large bore needle with minimal resistance. The technique has also been tried on palm fronds with limited success. Ongoing studies are suggested to determine which type of FBs is amenable to removal by this technique. Further, the concurrent use of a magnet with the needle may also potentially improve success rates and could be considered in future studies.<br />