The patient was a 48-year-old male. He was admitted to the hospital for 9 days because of a mass found in the right upper abdomen during physical examination. Past physical fitness. Laboratory test: Fibrinogen 16.83 mg/L, and the remaining test indexes were normal. Abdominal enhanced CT: A cystic mass was seen in the right front of the inferior hepatic segment of the inferior vena cava, with a size of about 3.8 cm ×4.6 cm ×5.5 cm and a clear boundary. A narrow neck was seen at the level of the renal hilum and communicated with the inferior vena cava, reaching the umbilical level downward. After enhancement, the lesion was enhanced in the same way as the inferior vena cava, so inferior vena cava aneurysm was considered. Because of low fibrinogen, vitamin K was given before operation110 mg intramuscular injection for 5 days, fibrinogen increased to 23.0 mg/L after reexamination. Under general anesthesia, the median laparotomy exposed the inferior hepatic vena cava. Exploration revealed a cystic mass behind the right peritoneum, about 4 cm ×5 cm in size, located below the right renal vein and confined to the inferior renal vena cava. The tumor is closely related to the inferior vena cava. It is separated along the edge of the tumor and the ureter is protected. The proximal end of the tumor is communicated with the right wall of the inferior vena cava with a thin pedicle with a diameter of 0.7 cm, and the distal end is connected with a bundle of plexiform blood vessels. It can be seen that blood is injected into the cystic tumor from the inferior vena cava, which is considered as type III cystic inferior vena cava aneurysm. Inferior vena cava aneurysm resection and inferior vena cava repair: the right part of the inferior vena cava was blocked with the auricular forceps, and the tumor and part of the inferior vena cava wall were cut off. The rupture of the inferior vena cava wall was sutured with 5-0 Prolene thread. After the auricular forceps were loosened, it was seen that there was no leakage in the inferior vena cava wall, and then the distal supply vessel of the tumor was cut off and double ligated (Figure 1). Pathology: cystic mass with a wall thickness of 0.1 cm, the sac is filled with a large amount of blood and blood clots, and the inner wall of the sac is smooth: the sac wall of smooth muscle tissue with varying thickness and thickness is seen under the microscope, lined with vascular endothelial cells, which is consistent with the diagnosis of venous aneurysm in combination with clinical practice (Figure 2). Rivaroxaban 10 mg/d was given after discharge to prevent venous thrombosis and possible pulmonary embolism.
