A Case of Traumatic Splenic Arteriovenous Fistula Treated by Transcatheter Arterial Embolization

Transcatheter arterial embolization (TAE) has increasingly replaced surgery for treating solid organ injuries, including the spleen, due to its minimally invasive approach. Studies show only a 3% splenectomy rate after TAE, despite a 10% incidence of missed vascular injuries in the American Association for the Surgery of Trauma (AAST) grade III splenic injuries on initial computed tomography (CT) scans. However, there's a lack of high-quality studies recommending specific CT follow-up intervals after non-operative management (NOM) of splenic injuries or guidelines for initiating treatment in cases of pseudoaneurysms or arteriovenous fistulas (AVFs). Here, we discuss the case of a 44-year-old man who presented with a splenic injury due to a motor vehicle accident. The splenic injury was AAST-spleen grade III, but because there was no evidence of extravascular leakage or AVF formation, NOM was selected. CT on the fifth day showed a pseudoaneurysm and an AVF, for which TAE was performed on the seventh day, preserving most of the parenchyma of the spleen with no complications. The indications for NOM as a treatment strategy for splenic injury are expanding, but since the 2018 revision of the AAST grading, the grade changes depending on the presence or absence of vascular injury, but in some cases, it is difficult to determine the presence or absence of active bleeding by CT findings. In fact, it has been reported that more than 25% of vascular lesions do not show up on CT, although CT has good sensitivity in detecting active bleeding, and the rate of NOM failure is higher in AAST grade III and above, so early angiography is likely to be useful. Splenic AVF may present with few symptoms in the early stages but may present with extrahepatic portal hypertension in the late stages, and patients may present to the hospital with symptoms such as abdominal pain and diarrhea. TAE is often the treatment of choice in traumatic cases, and the extent of embolization is important in the balance between preserving splenic function and completing treatment. The shift towards conservative management of splenic trauma may increase the occurrence of splenic AVFs. Transcatheter coil embolization of segmental branches has been effective in treating posttraumatic splenic AVFs, preserving splenic immune function and reducing risks linked to surgery and splenectomy.