Localization and Retrieval of an Eyelid Metallic Foreign Body With an Oscillating Magnet and High-Resolution Ultrasonography

[Contribution of technological aids to the extraction of orbital foreign bodies]

BACKGROUND

Removal of orbital foreign bodies is a surgical challenge. The purpose of this study is to report our experience in the removal of orbital foreign bodies and to evaluate the usefulness of various technological aids in their removal.

MATERIALS AND METHODS

We conducted a single-center retrospective study at Nice University Hospital (France) from January 2017 to December 2023. All patients undergoing surgery for an orbital foreign body during the study period were included. Data recorded included the nature of the orbital foreign body, its size, location, surgical route, outcome (success, partial success, failure), and technological aids used (intraoperative navigation, intraoperative imaging scope, orbital magnet). Concurrently, we designed a dedicated orbital magnet, which was tested in the anatomy laboratory and in two of our patients.

RESULTS

Six patients, all young men, were included during the study period. Removal was successful, partially successful, or unsuccessful in one-third of cases, respectively. Failure was associated with orbital foreign bodies located in the intraconal or posterior orbital space. Preoperatively, the use of a "low-artifact" scanner allowed us to better determine the exact size and shape of the orbital foreign body. Intraoperative navigation was not accurate enough, due to the mobility of the orbital bodies within the orbital fat. In our experience, intraoperative scope imaging was more accurate. The use of a dedicated orbital magnet was successfully tested in the anatomy laboratory and allowed the removal of a small orbital foreign body in one of our patients. Intraoperative surgical videos are provided.

CONCLUSION

Vegetal orbital foreign bodies must be systematically removed. Removal of non-vegetal orbital foreign bodies should be considered on a case-by-case basis based on their size, best assessed using a "low artifact" scanner, their location, and their intrinsic ferromagnetism. Intraoperative navigation does not appear useful, while intraoperative scope imaging does. A dedicated orbital magnet might be helpful in removing ferromagnetic orbital foreign bodies. However, an orbital magnet may be ineffective in removing intraorbital bullets, since they are made primarily of an alloy of copper and lead.

Minimally Invasive Magnetic Removal of Forehead Foreign Body

Residual foreign bodies are common sequelae of penetrating injuries. These may be left in situ or extracted and can be difficult to localize, often requiring wide exposure, which can be difficult to achieve in cosmetically sensitive areas. Different technological adjuncts are used to facilitate foreign body removal including fluoroscopy, ultrasound, and more recently, surgical magnets. This case describes and illustrates the unusual technique of using a sterile surgical magnet to both localize and remove a foreign body in the head and neck region using a minimally invasively technique.