Duodenal Invasion by Migrated Inferior Vena Cava Filter

A man in his 40s with a medical history of acute pulmonary thromboembolism due to protein C deficiency, for which an inferior vena cava (IVC) filter had been permanently placed 12 years previously, presented with persistent epigastric pain.Routine follow-up showed decreased protein C levels.However, abdominal ultrasonography revealed the migration of an IVC filter into the abdominal cavity (Picture 1A), and computed tomography indicated that 1 of the filter legs protruded into the duodenal horizontal segment.Subsequent esophagogastroduodenoscopy revealed transmu-