Duodenal and aortic stenting for aortoduodenal fistula secondary to malignancy: A case report

Abstract

BACKGROUND

Aortoduodenal fistula (ADF) managed with duodenal stenting has never before been reported in the literature.

CASE SUMMARY

A 75-year-old Chinese female with metastatic ureteric carcinoma presented with massive gastrointestinal bleeding secondary to ADF. Initial haemorrhage was managed with endovascular aortic repair and endoscopic haemostasis. However, she refused definitive open surgery. Her duodenal fistula was managed with partially covered stenting of the duodenum, which was complicated with duodenal stent migration. The duodenal stent was removed and replaced, and fixed in place with endoclips. She tolerated oral feeding until she passed away two months later.

CONCLUSION

This case report demonstrates that combined endoscopic and endovascular management of ADF can be feasible in selected patients.

Key Words: Aorto-duodenal fistula; Endovascular aortic repair; Endoscopic stenting; Stent migration, Complication; Case report

Core Tip: Aorto-duodenal fistula is a rare cause of gastrointestinal bleeding and most commonly managed with open surgery. This case reports the first ever use of minimally invasive treatment of aortoduodenal fistula with endovascular repair of aorta and endoscopic stenting of duodenum. The duodenal stent was complicated with migration, which can be prevented with clipping of the duodenal stent to the mucosa.

INTRODUCTION

Aortoduodenal fistula (ADF) is traditionally managed with open surgery, although endovascular aortic repair (EVAR) has been advocated even by International Societies[1]. However, management of the duodenal defect with endoscopic treatment has never before been reported.

CASE PRESENTATION

Chief complaints

A 75-year-old Chinese female complained of abdominal pain, dizziness and coffee-ground vomiting.

History of present illness

She was found unconscious by pedestrians and transported to the Department of Accident and Emergency, Pamela Youde Nethersole Eastern Hospital in April 2025. Patient complained of diffuse abdominal pain and dizziness, followed by one episode of coffee-ground vomiting. Shortly after admission, she developed cardiac arrest with pulseless electrical activity. Cardiopulmonary resuscitation was initiated and she had return of spontaneous circulation after 2 minutes.

History of past illness

She had a known history of right ureteral transitional cell carcinoma with aortocaval lymph node metastasis since November 2023. The patient received multiple lines of chemotherapy with slow progression of para-aortic nodal and pulmonary metastases. The latest computed tomography (CT) scan, performed two months prior to this admission, already demonstrated interval enlargement of the para-aortic lymph node closely abutting, or possibly invading, the third part of the duodenum.

Physical examination upon admission

Her abdomen was soft and nontender, and no pulsatile mass was felt.

Laboratory examinations

Emergency oesophagogastroduodenoscopy (OGD) revealed active bleeding from a large ulcer at the third part of the duodenum. Endoscopic haemostasis using adrenaline injection and hemospray was unsuccessful.

Imaging examinations

Given the patient’s poor premorbid status and suspected duodenal involvement by metastatic lymph node, laparotomy was not pursued. A CT angiogram (Figure 1) was performed to evaluate for embolization, which showed extravasation of contrast from infrarenal aorta into the third part of duodenum, diagnostic of ADF with haemorrhage. There were multiple gas locules within previously known para-aortic metastatic nodal conglomerates, which were encasing the aorta. There was no aortic aneurysm.

Figure 1 Computed tomography findings. A: Contrast computed tomography scan showing immediate extravasation of contrast from abdominal aorta at level L4/5 into duodenum. It is associated with the known para-aortic metastatic nodal conglomerates with multiple gas locules noted within, diagnostic of aortoduodenal fistula; B: Three-dimensional reconstruction showing extravasation of contrast from the right lateral wall of the aorta into the 3^rd part of the duodenum.

MULTIDISCIPLINARY EXPERT CONSULTATION

A multidisciplinary discussion involving the patient’s family, intensivist and oncologist concluded that, despite her slowly progressive terminal malignancy, the patient had remained ambulatory with satisfactory quality of life prior to admission, and her oncological survival potentially exceed six months. The family opted for EVAR to control active bleeding, knowing that it is a temporizing measure with high risk of infection without definite open repair, for which the patient was likely unfit.

FINAL DIAGNOSIS

The final diagnosis was ADF.

TREATMENT

Aortic intervention

Emergency EVAR was performed for haemostasis despite her abdominal aorta measuring only 12-14 mm, below the minimum requirement. The aorto-enteric fistula was covered with the smallest bifurcated stent-graft and bilateral iliac extensions. Completion angiography showed proper graft placement without extravasation or endoleak (Figure 2).

Figure 2 Endovascular aortic repair imaging. A balloon molding of the smallest bifurcated stent-graft in the narrow aorta, to cover the aortoduodenal fistula; B: Completion angiography showed proper graft placement without extravasation or endoleak.

The patient recovered well following EVAR, thus definitive open repair for ADF was offered. However, upon regaining consciousness, she declined open surgery given her underlying terminal malignancy and expressed wish for comfort care.

She was initially managed by keeping strict nil per oral with intravenous proton pump inhibitor and antibiotics. Enteral feeding was resumed via a nasojejunal tube placed distal to the duodenal defect. Her quality of life was poor and she was not able to be discharged.

Endoscopic stenting

Other nonsurgical methods of pallative treatment were explored and duodenal stenting was offered (Figure 3). OGD was performed on post EVAR day 17 to deploy two partially covered, self-expanding metal stents – one across the pylorus and another across the duodenal defect, overlapping by 2 cm. The patient made a good recovery and could tolerate oral diet after the procedure. She was discharged with a prolonged course of antibiotics.

Figure 3 Endoscopic views of aortoduodenal fistula and stenting. A: Endoscopic intraluminal view of aortoduodenal fistula; B: Partially covered stent allows coverage of duodenal defect whilst not covering the ampulla; C: Stent anchored with endoclips to prevent migration.

OUTCOME AND FOLLOW-UP

Endoscopic re-intervention

Two weeks later, the patient was readmitted for a follow up CT scan, which incidentally found that both the duodenal stents had migrated. OGD guided removal of stents was done and subsequently a single partially covered, self-expandable stent was placed from the pylorus to the 4^th part of the duodenum. The stent was anchored to the duodenum with multiple endoscopic clips. She could tolerate oral diet after the procedure.

Outcome

The patient eventually developed cauda equina syndrome secondary to infective spondylitis and sepsis as evidenced by blood culture growing polymicrobial bacteremia, despite being on long-term antibiotics. The patient was eventually managed with palliative care, and she passed a month later.

DISCUSSION

This is a rare case of ADF caused due to metastatic cancer in para-aortic lymph nodes, invading into the duodenum and aorta. Saers and Scheltinga[2] showed that the most common cause of ADF is aortic aneurysm, while less than 10% of ADF are caused by cancer related etiologies. Aorto-enteric fistula after abdominal aortic aneurysm repair (open or endovascular) is considered secondary. Aorto-enteric fistulas are primary if there was no preceeding aortic intervention[3].

The classical triad of ADF include gastrointestinal (GI) bleeding (as much as 94% of patients affected), pain and pulsating mass on abdominal palpation. Yet this triad is only present in around 11% of patients[4]. Moreover, the differential diagnosis of ADF is often overlooked as it has a very low prevalence (around 0.07% for primary ADF and 1.6% after open abdominal aortic aneurysm repair)[5]. These make the diagnosis of ADF difficult and a high index of suspicion is required.

Workup of ADF includes contrast-enhanced CT angiography and OGD. CT angiography has a low sensitivity (50%), and a high specificity (100%) for diagnosing ADF[6], which makes it highly reliable in positive results, but also a negative result does not necessarily rule out ADF. OGD is an important investigation for upper GI bleeding, which is the most common presentation of ADF. However, the endoscopist must be aware of the possibility of ADF, as the pathology may only be detected if the scope is put down to the 3^rd or even the 4^th part of the duodenum[7]. It is reported that OGD can only detect 25%-50% of ADF[8].

The surgical management of ADF requires management of the aorta and the management of the duodenum. The management of the aorta has traditionally been with open surgery. In an infected surgical field, such as in a patient with ADF, after wide debridement, the options of aortic repair include using spliced autologous femoral vein graft[9], antibiotic-impregnated prosthetic graft[10], or aortic transection and extra-anatomical bypass (e.g. axillo-femoral bypass)[11], which is the historical golden standard[12]. Yet, emergency ultra-major surgery for ADF carries a mortality rate around 30%-40%[13].

Another approach is EVAR, which has revolutionized the management of aortic aneurysm and is also utilised in ADF as a bridge to definitive surgery[1]. The ESVS guidelines on Vascular Graft and Endograft Infections 2020[14] recommend initial temporary treatment with an endograft in the emergency setting of active bleeding of aorto-enteric fistula (class IIb). EVAR has also been used in the reported patient to achieve hemostasis and to manage the aortic defect.

The surgical management of the duodenum in ADF has also mainly been with open surgery[15]. However, advances in endoscopy allowing for closure of full thickness defects of the GI tract have been reported[16].

The reported patient refused definitive treatment of ADF with open surgery, so endoscopic options were being explored. The endoscopic treatment options of duodenal fistula included primary closure of the defect (e.g. with through-the-scope or over-the-scope endoclips) as Berner-Hansen et al[17] suggested that endoscopic clips or stents could be used to manage aorto-enteric fistula before open surgery. However, clipping was not feasible for this patient because of large defect size and friable ulcer edges. Instead, partially-covered duodenal stenting was used, aiming to exclude the duodenal fistula defect. Fully covered duodenal stent has the disadvantage of causing biliary obstruction and higher chance of migration compared to partially covered stent. The treatment of duodenal stenting may facilitate oral feeding and a better quality of life[18].

Whilst being minimally invasive, endoscopic stenting of the duodenum for ADF has several limitations. First, stents are prone to migration (9.1% risk of migration for partially covered, self-expandable metal stent used in GI pathologies)[19]. Measures to prevent migration such as clipping of the stent to anchor it to the duodenum are recommended[20]. Another is that even though defect coverage could reduce chance of recurrence and sepsis[21], they do not control existing infection, and in fact, infected stent (e.g. EVAR stentgraft) is an anticipated complication - hence the need for lifelong antibiotics. IV antibiotics and percutaneous drainage may control the sepsis temporarily, but inadequate source control means that the infection may worsen and spread[22] – as evidenced by this reported patient with infective spondylitis due to posterior local invasion by the retroperitoneal collection, due to being in a prolonged supine position.

The reported outcome for patients after EVAR is limited. Kehagias et al[21] reported apparently 41.6% long term survival for post EVAR aorto-enteric fistula patients. In their series, EVAR was definitive therapy for 8 out of 12 patients. Antoniou et al[3] in their systematic review showed that infection occurred in 44% of patients after EVAR for aorto-enteric fistula after a mean follow up of 13 months.

We hope that this first reported case of duodenal stenting for ADF would help others to consider it as a treatment option, as well as being aware of the risk of stent migration. Our opinion is that endoscopic management of ADF may be feasible for some patients, and could be considered, especially in patients who are not candidates for open surgery.

CONCLUSION

To our knowledge, this is the first reported case of duodenal stenting used after EVAR in ADF secondary to cancer metastasis. This is a rare disease with high mortality, therefore high clinical suspicion is needed to correctly diagnose and treat this condition. Duodenal stenting may facilitate oral feeding but carries a risk of stent migration and uncontrolled sepsis[23]. It may be feasible in selected patients with limited life expectancy in centres with expertise.