Urinary excretion after transcaval renal penetration of a fragmented Bird's Nest filter.

Permanent inferior vena cava (IVC) filters are used to prevent venous thromboembolic events in select populations of patients. The Bird's Nest filter (BNF; Cook Medical, Bloomington, Ind) is an IVC filter that has been associated with various complications including filter strut fractures, migration, caval wall perforation, visceral perforation, and vascular injury. We report a case of a BNF that eroded transmurally through the IVC into the right kidney parenchyma. The patient underwent operative intervention with removal of the BNF with an uncomplicated postoperative course. In patients with symptoms and local filter perforations, we advocate for safe filter removal when possible to avoid long-term damage.