A 63-year-old man comes to the emergency department due to pain and swelling of the right calf. He has a history of recurrent gastrointestinal hemorrhage and was discharged from the hospital 4 days ago following a prolonged admission for diverticular bleeding requiring multiple blood transfusions. Temperature is 36.7 C (98 F), blood pressure is 110/60 mm Hg, pulse is 92/min, and respirations are 18/min. Compression ultrasonography with Doppler reveals deep venous thrombosis in the right popliteal vein. A filter placement is planned to prevent embolization. A section of the patient's abdominal CT at the level of L2 is shown in the image below. The filter will most likely be placed in which of the following structures?

Question

A 63-year-old man comes to the emergency department due to pain and swelling of the right calf.  He has a history of recurrent gastrointestinal hemorrhage and was discharged from the hospital 4 days ago following a prolonged admission for diverticular bleeding requiring multiple blood transfusions.  Temperature is 36.7 C (98 F), blood pressure is 110/60 mm Hg, pulse is 92/min, and respirations are 18/min.  Compression ultrasonography with Doppler reveals deep venous thrombosis in the right popliteal vein.  A filter placement is planned to prevent embolization.  A section of the patient's abdominal CT at the level of L2 is shown in the image below.  The filter will most likely be placed in which of the following structures?

Quizplus · Accepted Answer

11ec160b_3565_adf6_9249_8316efaa4c55_MD0001_00 This patient with deep venous thrombosis (DVT) has had recurrent episodes of gastrointestinal hemorrhage, including a recent one requiring prolonged hospitalization. Given the risk of bleeding associated with anticoagulation therapy in this patient, inferior vena cava (IVC) filter placement is planned. IVC filters are designed to prevent the embolization of DVT from the legs to the lung vasculature (ie, pulmonary embolism), and are used in patients who have contraindications to anticoagulation. CT images are always visualized as though standing at the patient's feet and looking through the patient's body toward the head; therefore, the left side of the image corresponds to the patient's right side. Both kidneys are viewed in this section, and the inferior pole of the right lobe of the liver is noted anterior to the right kidney and posterolateral to the large bowel. The filter will be placed in the IVC, which lies medial to the descending part of the duodenum and anterior to the right side of the vertebral body. The common iliac veins merge to become the IVC inferior to this plane of section at the L5 level. (Choice A) With its dark center, representing an air-filled lumen, and mucosal folds, this structure is likely the second (descending) part of the duodenum, which typically lies at the level of L2. (Choice C) This structure represents the abdominal aorta, which bifurcates at the level of L4. The structure is on the patient's left, so it is unlikely to be the IVC. (Choice D) This structure likely represents the fourth (ascending) part of the duodenum. This CT section likely captures only the wall of the fourth part of the duodenum as it briefly courses transversely across the abdomen (before descending as the jejunum), so the lumen is not visible. (Choice E) This structure is likely the left renal vein. The left renal vein receives drainage from the left gonadal vein and courses anterior to the aorta, but posterior to the superior mesenteric artery, before draining into the IVC. Educational objective: The inferior vena cava (IVC) courses through the abdomen and inferior thorax in a location anterior to the right half of the vertebral bodies. The renal veins join the IVC at the level of L1/L2, and the common iliac veins merge to become the IVC at the level of L5. IVC filters are placed in patients with deep venous thrombosis who have contraindications to anticoagulation therapy.

A 63-Year-Old Man Comes to the Emergency Department Due to Pain