Intraorbital Mercury Removal by DSA Positioning and Route Marking: A 4-year Follow-up

Background: Mercury is a widely used heavy metal. Traumatic mercury residue often leads to contact dermatitis, granuloma, even chronic poisoning. Due to its unique physical and chemical properties, mercury beads can be difficult to retrieve, especially in the eyes. Most previous studies have focused only on the rigid orbital foreign bodies rather than the injuries related to liquid heavy metal and their extraction method. Methods: : We reported a case of thermometer-related orbital injuries in a 4-year-old boy. To better locate, visualize and remove the mercury beads without complications, a Digital Subtraction Angiography (DSA)-guided, methylene blue marked access was taken, followed by further removal of scattered tiny mercury droplets with an adapted aspirator. Result: At least 0.7411g mercury was taken out during the surgery. After a four-year follow-up, the boy had no residual symptoms, with his urine mercury decreased gradually. Conclusion: Assessing the risk-return coefficient and making an appropriate therapeutic plan is an integral part of the pursuit of therapeutic progress. With the guidance of DSA and methylene blue, the suction of the reformative aspirator, we finally locate the mercury beads, maximize the removal of beads, reduce the length and depth of incisions, and keep the essential structures intact. Hence, we found it a valuable surgical skill on such occasions, worth sharing for future references.