Introduction
Coil migration is a rare complication following arterial embolization for visceral aneurysms and an infrequent cause of peptic ulcer bleeding [1]. The migrated coil can erode into adjacent gastrointestinal structures, forming a fistula between the vasculature and the digestive tract, which may result in gastrointestinal bleeding [2]. Clinical presentation can range from being asymptomatic to upper abdominal pain and gastrointestinal hemorrhage.
Currently, there is no standardized treatment protocol [2–4]. Here, we present a representative case from our department in which a patient developed gastrointestinal hemorrhage due to spring coil migration, with notable symptom improvement following surgical intervention.
Case presentation
A 70-year-old Chinese man presented to the digestive department with a 5-day history of vomiting and melena. He reported no history of tobacco, alcohol addiction, viral hepatitis, biliary tract disease, or peptic ulcer. Six years ago, he was diagnosed with erythema nodosum and received long-term immunosuppressive therapy, which he discontinued nearly 3 months ago.
The patient underwent hepatic artery embolization and stent placement from celiac trunk to splenic artery owing to a ruptured hepatic artery aneurysm at another hospital 2 years ago. Physical examination revealed no unusual findings except for anemic facies. Blood routine revealed a hemoglobin level of 9.7 g/dL and a red blood cell count of 3.14 × 1012/L.
Liver function, coagulation function, and platelet counts were within normal ranges. Gastroscopy showed duodenal bulb ulcer and bleeding, with a long strip-like metal foreign body visible at the center of the ulcer (Fig. 1).
Contrast-enhanced computed tomography (CT) revealed nodular dense shadows in the head of the skin glands and revealed a metal foreign body penetrating from the hepatic artery into the duodenal bulb (Fig. 2). Computed tomography angiography (CTA) showed post-embolization changes of a hepatic artery aneurysm, with the stent positioned between the truncus coeliacus and the splenic artery, and distal splenic artery aneurysmal dilation (Fig.
3). The final diagnosis was gastrointestinal hemorrhage due to a fistula between a hepatic aneurysm and a duodenal bulb ulcer, precipitated by spring coil migration.Fig. 1Gastroscopy showed duodenal bulb ulcer and bleeding, with a long strip-like metal foreign body visible at the center of the ulcerFig.
2Computed tomography revealed nodular dense shadows in the head of the skin glands and revealed a metal foreign body penetrating from the hepatic artery into the duodenal bulbFig. 3Computed tomography angiography shows post-embolization changes of a hepatic artery aneurysm, with the stent positioned between the truncus coeliacus and the splenic artery, and distal splenic artery aneurysmal dilation
Our patient underwent a surgical procedure. The surgical procedure revealed a 4 cm abscess cavity in a common hepatic artery aneurysm, which communicated with the posterior wall of the duodenal bulb and a stent located between the truncus coeliacus and splenic artery. The 60-cm-long spring coil, the splenic artery stent, and the celiac trunk artery stent were removed.
The patient underwent duodenal fistula repair surgery, resection of the common hepatic artery, and ligation of the truncus coeliacus (Fig. 4). In follow-up, the patient recovered well with no further symptoms of vomiting or melena, and hemoglobin levels increased significantly.Fig.
4The 60-cm-long spring coil, the splenic artery stent, and the celiac trunk artery stent were removed. The patient underwent duodenal fistula repair surgery, resection of the common hepatic artery, and ligation of truncus coeliacus
Discussion
Visceral artery aneurysms (VAAs) are characterized by abnormal dilatation of abdominal visceral arteries, including the splenic, hepatic, and mesenteric arteries. These aneurysms carry a significant risk of rupture, with associated mortality rates ranging from 25% to 27% [5]. The development of VAAs is associated with multiple underlying factors, such as atherosclerosis, hypertension, connective tissue disorders, fibromuscular dysplasia, and infectious conditions [5].
Endovascular embolization involves the implantation of coils via interventional radiology techniques to occlude aneurysmal blood flow and prevent rupture. Further, coils are widely used as embolization materials. It is currently the preferred treatment for VAAs; however, the rate of re-intervention remains substantial, reported between 15% and 25% [6].
Although the incidence of complications is low, the risk of coil migration remains. There was no clear difference in short- and long-term mortality between the endovascular approach and open surgery for hepatic aneurysms [6].
Gastrointestinal bleeding (GIB) following interventional procedures is a rare but serious complication, with an incidence ranging from 2% to 10% [2]. The risk of GIB after splenic artery embolization is relatively high, reported at 3–8%. In contrast, the incidence after hepatic artery embolization is less than 2%; however, when it occurs, it is often associated with severe clinical consequences [1].
Nomura reported the first case of coil migration to the duodenum after common hepatic artery embolization in 2018 [4]. The exact mechanism of migration is unknown. Existing research speculates that GIB caused by hepatic artery coil migration involves three primary pathological mechanisms [2–4, 7].
First, the coil may penetrate the arterial wall and directly erode into the gastrointestinal tract, leading to mucosal injury or perforation. Second, post-embolization ischemia can induce ulcer formation, and the presence of the coil as a foreign body may intensify the local inflammatory response. Third, hemodynamic factors such as portal hypertension or blood flow turbulence may displace the coil, resulting in mechanical instability and increased risk of erosion.
Our patient has a history of erythema nodosum. We speculate that immune activation, foreign body reaction, and vascular endothelial injury are key contributing factors linked to delayed bleeding following interventional embolization. In patients with autoimmune diseases, these conditions may amplify the local vascular inflammatory response induced by embolic coils, thereby increasing the risk of delayed bleeding after interventional procedures [8].
Further research is required to investigate whether local vascular inflammation in the context of autoimmune diseases could contribute to coil migration.
Clinical manifestation, imaging, and gastrointestinal endoscopy must be used in conjunction to diagnose the disease [7]. CT can reveal the relationship between the coil and adjacent organs, and CTAs provide reliable information about the vasculature [5, 7]. Direct evidence of bleeding and coil displacement can be seen on gastrointestinal endoscopy.
There is no standard treatment for hemorrhagic common hepatic artery aneurysm and duodenal bulbar fistula hemorrhage caused by spring coil migration. Coil removal by endoscopy or surgery has been reported [2, 7, 9]. According to existing research, open surgery continues to be the most widely adopted treatment approach, while endoscopic intervention may be considered for asymptomatic patients [2].
Endoscopic hemostasis or retrieval of migrated spring coils is primarily indicated in cases of superficial migration [9, 10]. Endovascular techniques, such as re-embolization or percutaneous removal of displaced coils via interventional radiology, have demonstrated safety and efficacy; however, these approaches are associated with a relatively high risk of requiring re-intervention [6]. In our case, open surgery is challenging and may require subtotal gastrectomy and may result in bleeding, life-threatening hemorrhagic shock, postoperative sepsis, and multiple organ failure.
After multidisciplinary treatment, and considering the high risk of life-threatening hemorrhage during endoscopic intervention owing to erythema nodosum, multiple systemic vascular aneurysms, and fistula enlargement, open abdominal surgery was cautiously selected as the preferred treatment approach. The patient demonstrated favorable recovery after the procedure.
Conclusion
To the best of our knowledge, no cases of GIB secondary to spring coil migration have been reported in patients with erythema nodosum, and there is currently no standardized treatment approach for this condition. Gastrointestinal bleeding resulting from spring coil displacement can be life-threatening, making multidisciplinary collaborative decision-making essential during treatment. In the event of such a critical hemorrhage, timely surgical intervention can be effectively initiated through coordinated decision-making by a multidisciplinary team.