Secondary Aortoduodenal Fistula Research Articles

Secondary aorto-duodenal fistula: a diagnostic challenge in a patient with fever and anemia.

A 69-year-old male, three years post-endovascular exclusion for an abdominal aortic aneurysm, presented with asthenia and fever. An abdominal CT scan showed no gastrointestinal tract communications, abscess, or contrast extravasation. Tc-99m-HMPAO-labeled leukocytes scintigraphy with SPECT/CT revealed increased uptake on the posterior surface of the aortic graft, along with air bubbles in its right iliac limb. Upper gastrointestinal endoscopy was performed, revealing a duodenal ulcer in the transition between the second and third portions. The ulcer exhibited yellow graft tissue at its center. The patient underwent in situ reconstruction, involving the replacement of the infected prosthetic graft, and the duodenal defect was addressed through segmental resection and duodenojejunal anastomosis. Secondary aorto-duodenal fistula (SADF), a rare complication of vascular surgery, may arise from factors such as local infection or graft-bowel contact. SADF, often located in the duodenum, poses a high mortality risk, necessitating early diagnosis. Clinical presentation varies from significant upper gastrointestinal bleeding to obscured bleeding.

A case of aortoduodenal fistula presenting with postoperative lymphatic leakage.

Introduction and importanceSecondary aortoduodenal fistula (sADF) is a complication of prosthetic graft replacement of the abdominal aorta which often follows a fatal course. This report details our experience with a case of lymphatic fistula that developed after sADF repair. The fistula was refractory to conservative treatment but ultimately responded to lipiodol lymphangiography.Case presentationA 75-year-old man had undergone prosthetic graft replacement to treat an abdominal aortic aneurysm in 2012 and a thoracic aortic aneurysm in 2015. Upper gastrointestinal endoscopy was performed in 2020, and examination for worsening anemia revealed that the abdominal aortic graft had eroded into the horizontal duodenum. The patient was treated with prosthetic graft replacement and duodenectomy. A refractory lymphatic fistula was noted after surgery, which made ascites accumulation difficult to control, but the patient's condition rapidly improved following therapeutic lymphangiography.Clinical discussionSurgery is the first-line therapy for sADF, but clinicians must stay vigilant for infection recurrence and aortoenteric fistulae after a repair, and this requires patient-specific postoperative management. Our modifications, intended to minimize contamination of the operative field in the present case, also facilitated our ability to subsequently treat a refractory lymphatic fistula, which is a rare postoperative complication of the procedure.ConclusionProcedural modifications to sADF repair aimed at minimizing perioperative contamination are crucial for preventing infection recurrence. Given the extent of invasion, the surgery can cause various postoperative complications, requiring individualized strategies for management and treatment. Therapeutic lymphangiography is one such approach, which holds promise as a first-line treatment for refractory lymphatic fistula.

Aorto-duodenal fistula secondary to aortic graft replacement

Secondary aorto-duodenal fistula (SADF) is a rare and serious event occurring in up to 45% of aortic prosthesis infections. The clinical manifestations are variable ranging from isolated signs of graft infection such as fever to massive gastrointestinal bleeding. The diagnosis is based on CT scan and is generally oriented by an inconstant association of indirect signs. Despite a high early severe postoperative morbidity and mortality, especially in presence of a preoperative shock, emergency surgery allows for the diagnosis and treatment of SADF with multidisciplinary management allowing favorable midterm outcomes among surviving patients. The images that we present in this manuscript highlight some indirect signs of SADF on CT scan that should alert clinicians to warrant on time surgical management with an illustration of per operative diagnosis of the fistula.

Aortoduodenal fistula - fatal complication in a patient with aortic prosthesis

Purpose: Aortoenteric fistula is an extremely rare source of upper gastrointestinal tract haemorrhage (UGIH).
 Case report: We present the case of a 58-year-old man who was admitted to our ward with UGIH. During diagnosis, urgent upper and lower GI endoscopy, abdominal US, CT angiography and ileojejunography were performed. Unfortunately, the bleeding source was not found and the patient was discharged. He returned 2 weeks later with profound anemia. Urgent upper GI endoscopy did not elucidate the bleeding source. The patient died suddenly a few days after receiving symptomatic treatment. At autopsy, a secondary aortoduodenal fistula due to prosthetic aortic reconstruction was found, which had led to fatal haemorrhage.
 Conclusion: Some sources of UGIH are very rare. In the diagnostic work up of these patients we should be aware of the limitations of different imaging procedures.

高度貧血を契機に診断されたステントグラフト内挿術後腹部大動脈瘤：十二指腸瘻の1例(Secondary aorto–duodenal fistula following endovascular abdominal aortic aneurysm repair diagnosed by severe anemia)

要旨腹部大動脈ステントグラフト（EVAR）は腹部大動脈瘤（AAA）に対する主な治療として位置づけられ，とくに開腹歴をもつ症例群に対する加療として，低侵襲性の観点で積極的に施行されている。EVAR後に発生するエンドリークは，治療にも関わらず瘤径拡大の主原因であり，周囲臓器との瘻孔や瘤破裂の発生などEVAR関連合併症が発生しうる。EVAR後の大動脈腸管瘻（AEF）の発生は非常に稀であるが，致命的な合併症として知られる。我々は，大腸癌で開腹歴をもつ70歳代女性の拡大傾向のある嚢状AAA対してEVARを施行したが，瘤拡大が持続し十二指腸に穿破した症例を経験した。EVAR術後6か月，16か月後にそれぞれエンドリークによる瘤径拡大に対する追加加療を行ったが，瘤径の制御が困難であった。術後20か月後に高度貧血に対する精査のために施行された上部消化管内視鏡検査の結果，AAAが十二指腸水平脚と交通し出血している所見を認め，AEFの診断となり緊急手術を行った。周術期死亡率の高い本症において，手術侵襲が大きくなることが予想される症例に対して，ステントグラフトを抜去せず瘤縫縮術を選択した1例を報告した。EVAR後の瘤拡大関連イベントに救急医が関わるケースが増えてくることが予想され，AEFの合併を念頭に置くべきである。

Mid-Term Results of Endovascular Aneurysm Sealing in the Treatment of Abdominal Aortic Aneurysm With Unfavorable Morphology.

To report mid-term results of endovascular aneurysm sealing (EVAS) of abdominal aortic aneurysms (AAA) deemed unsuitable for a standard endovascular aneurysm repair (EVAR). A prospectively maintained database of 42 patients with EVAR-unfavorable anatomy treated by EVAS combined with chimney grafts in case of the proximal AAA neck shorter than 5 mm was analyzed. Early outcomes included final angiographic result, intra- and early post-operative deaths, and complications. Mid-term outcomes included all-cause mortality (ACM), aneurysm-related mortality (ARM), patency of the stents, occurrence of endoleaks, serious complications and graft failures defined as the AAA growth of more than 5 mm, type I endoleak, occlusion of the stent-graft or chimney graft, aorto-duodenal fistula, or aneurysm rupture. The procedure was completed in all patients. Twenty-eight chimney grafts were implanted in 19 patients. Patients were followed for a median of 24 months (range 12-34 months). There were 2 intraoperative ruptures and 1 patient died in an early postoperative period. The cumulative ACM was 15, 21, and 36% at 12, 24, and 36 months, respectively, and the cumulative ARM was 8, 11, and 27% at 12, 24, and 36 months, respectively. Three out of 5 aneurysm-related deaths were due to a secondary aorto-duodenal fistula. The cumulative incidence of graft failure was 20, 27, and 42% at 12, 24, and 36 months, respectively. The cumulative incidence of an endoleak was 5, 9, and 23% at 12, 24, and 36 months, respectively. The graft failure increased significantly both ACM (p = .012) and ARM (p = .00003). The implantation of chimney grafts at the initial procedure increased ARM significantly (p = .008). The presence of an endoleak did not have any significant influence on ACM and ARM. Patients treated with EVAS for AAAs with EVAR-unfavorable anatomy, especially those with chimney grafts, exhibit a high risk of graft failure and subsequent death.

S2209 Primary Aortoduodenal Fistula in a Native Aorta Causing Brisk Upper GI Bleeding

INTRODUCTION: Primary aortoduodenal fistula (ADF) is a rare cause of gastrointestinal bleeding and is difficult to diagnose. Computed tomographic angiography (CTA) can be used to detect primary ADF. Open surgery or endovascular aortic repair (EVAR) for ADF improves survival. CASE DESCRIPTION/METHODS: 73-year-old male with atherosclerotic, native, non-surgically altered, normal diameter aorta complicating ADF presented with massive GI bleeding. Initially at outside hospital and was evaluated for intermittent episodes of hematemesis and hematochezia for one month. Repeated endoscopy failed to identify a source of bleeding, but blood was seen within the colon. Nuclear scans and CTAs showed no sources of active bleed/fistulas. He was transferred to our facility for further evaluation. On admission, he was in shock with a significant drop in his Hgb. Repeat endoscopy revealed a non-bleeding ulcer with a large visible vessel in the 3rd portion of the duodenum (Figure 1). Given the location and size, was felt not to be amenable to endoscopic therapy. Patient bled overnight. Urgent CTA showed active intraluminal hemorrhage within the duodenum and proximal jejunum, and abnormal periaortic soft tissue concerning for ADF (Figure 2). The Patient was taken to the IR and was found to have an ADF. Vascular surgery was consulted intra-operatively and performed an EVAR with stent-graft of the infrarenal aorta. The patient’s GI bleeding resolved. DISCUSSION: Primary ADF is an abnormal communication between the infrarenal aorta and duodenum involving the 3rd part of the duodenum in 2/3rd of cases and the 4th part in 1/3rd of cases. Primary ADF is an extremely rare entity. There were 791 ADF cases reported between 1951 and 2010, including 253 cases of primary ADF and 491 cases of secondary ADF. Of the primary cases, all included the presence of AAA. Our case is a patient with brisk upper GI bleeding, without high suspicion of ADF due to his history of a native, nonenlarged, unaltered aorta. We believe the pathophysiology of this case was a weakened aortic wall and inflammation secondary to chronic atherosclerosis resulting in fistula formation to the duodenum. A timely and accurate diagnosis of primary ADF may be challenging due to insidious episodes of GI bleeding, which are frequently under-diagnosed until the occurrence of massive hemorrhage. Clinicians should keep a high index of awareness for primary ADF, especially in elderly patients with unknown etiology of brisk upper GI bleeding with or without a known AAA.Figure 1Figure 2

Aortoduodenal fistula after abdominal aortic aneurism resection: Two case reports

Introduction. Aortoenteric fistula (AEF) is rare and extremely difficult complication of aortic surgery. We presented two cases of secondary aortoduodenal fistula (SADF) as complication after aortic surgery. Case reports. In the first patient SADF happened 11 years after open abdominal aneurysmal resection with gastrointestinal tract (GIT) bleeding. After negative esophagogastroduodenoscopy (EGDS) we performed multislice computed tomography (MSCT) which revealed contrast leakage in duodenum from 10 cm wide visceral aortic aneurysm. The patient was treated with graft excision, aneurysmal reduction, sewing of proximal and distal aortal stumps, bowel repair followed by axillobifemoral bypass (AxFF). The patient dismissed on 30th postoperative day. The second case of ADF happened five months after endovascular reconstruction of abdominal aorta with GIT bleeding and fewer. During following 8 days, he had three negative EGDS. On MSCT we found signs of endoleak, free air in aneurysmal sac, and signs of blood in the intestine. On urgent operation we extracted stent graft, sewed proximal and distal aortal stumps, performed bowel repair and AxFF. The patient died a day after operation with signs of sepsis and multiple organ failure syndrome. Conclusion. Conventional treatment of ADF means extraanatomic AxFF with complete excision of infected graft or stent graft, with closure of aorta?s proximal and distal stumps and duodenal repair. Because of high mortality, prompt diagnostic evaluation and quick decision of an adequate operative treatment is necessary. Although European Society of Vascular Surgery recommendations, as a guide, are very helpful, there is no unique attitude about management of AEF, so each patient should be specifically treated.

Case Report: Rupture Despite In-Situ Repair of a Secondary Aortoenteric Fistula with Autologous Femoral Veins

Introduction - A secondary aorto-enteric fistula is a direct communication between aorta and intestinal lumen after a reconstructive procedure of the abdominal aorta. Methods - We describe a case of secondary aortoduodenal fistula that occurred eight years following open repair of an abdominal aortic aneurysm. This case illustrates the complexity of the pathology and describes the surgical approach. Results - A 63-year-old man, who underwent an open repair of an aneurysmal abdominal aorta 8 years ago, was referred by infectious diseases because of suspicion of an infected Dacron graft. He was empirically treated with intravenous (IV) antibiotics in another hospital 1 month earlier. Oral antibiotics were continued awaiting further investigations and definitive treatment. One month later he was admitted to the emergency room in sepsis with a proven secondary aorto-enteric fistula on Computed Tomography (CT) angiography and esophagogastroduodenoscopy. An in-situ repair with autologous superficial femoral veins was performed and the defect in the duodenum was closed. Peroperative cultures showed Candida Lusitaniae and Lactobacillus. This procedure was complicated with abscess formation and recurrent sepsis. Percutaneous CT guided drainage and IV antibiotics were successful but after removal of the pigtail, the patient developed acute back pain caused by a pseudoaneurysm noted at the left autologous femoral vein graft. Emergency repair was undertaken with suturing of the aortic stump and extra-anatomic reconstruction with prolonged IV antibiotics and antimycotics. Patient was discharged six weeks after the extra-anatomic reconstruction and the antimycotic therapy will be continued for one year. Conclusion - Despite surgical repair of a secondary aorto-enteric fistula with in-situ replacement with autologous venous material and prolonged antibiotics, this patient still developed a rupture of the venous graft requiring an extra-anatomic reconstruction.

Long-term Results of Endovascular Aneurysm Sealing in Treatment of Infrarenal Abdominal Aortic Aneurysm With Unfavourable Morphology

Introduction: Endovascular aneurysm repair (EVAR) is a less invasive alternative of treatment of patients with abdominal aortic aneurysm (AAA). Its applicability however is limited by the AAA anatomy. Endovascular aneurysm sealing originally emerged as an endovascular solution for AAA repair with very promising early results. The purpose of this study was to report long-term results of EVAS of AAAs with unfavourable anatomy for EVAR. Methods: A prospectively maintained database of 42 patients with EVAR-unfavourable anatomy treated by EVAS was analysed. The median age of the patients was 74 (IQR 67-80) years. The median diameter of AAA was 61 (IQR 56-71) mm. The EVAS consisted of implantation of two balloon expandable aorto-iliac stent-grafts surrounded by polymer filled endobags. In case of proximal AAA neck shorter than 5 mm chimney grafts were implanted. The final angiographic result, intra- and early post-operative complications were noted. A follow-up included a clinical assessment angio-CT 4-6 weeks and 12 months after the procedure and duplex Doppler at 12 months intervals thereafter. In case of any abnormalities detected in either clinical or duplex Doppler examination an angio-CT was performed. Patency of the aorto-iliac stents and chimney grafts, occurrence of graft failure and all additional interventions and/or events were noted in the database. The graft failure was defined as AAA growth of more than 5mm, type I endoleak, occlusion of the stent-graft or chimney graft or aneurysm rupture. All-cause mortality (ACM) and aneurysm related mortality (ARM) were analysed with Kaplan-Meier estimates. Results: The procedure was completed in all patients. Twenty-eight chimney grafts were implanted in 19 patients. There were two intraoperative ruptures, one of an aortic neck that required conversion to an open repair and one of an external iliac artery that was successfully treated with implantation of a self-expandible covered stent. One patient died in an early postoperative period. The median follow-up period was 24 (IQR 12-34) months. The cumulative ACM was 15, 21 and 35% at 12, 24 and 36 months respectively and the cumulative ARM was 8, 11 and 27% at 12, 24 and 36 months respectively. Three out of five aneurysm related deaths were due to a secondary aorto-duodenal fistula. The cumulative incidence of graft failure was 20, 27 and 42% at 12, 24 and 36 months, respectively. Cumulative incidence of endoleak was 5, 9 and 23% at 12, 24 and 36 months, respectively.The graft failure increased significantly both ACM (p = 0,012) and ARM (p = 0,00003). The implantation of chimney grafts at the initial procedure increased significantly ARM (p=0,008). The presence of endoleak did not have any significant influence on ACM and ARM. Conclusion: Patients treated with EVAS for AAA with EVAR-unfavourable anatomy, especially those with chimney grafts, have a high risk of graft failure and subsequent death. These patients require more rigorous monitoring than patient after standard EVAR. Disclosure: Nothing to disclose

Contemporary Management of Secondary Aortoduodenal Fistula

Secondary aortoduodenal fistula (SADF) is a rare, life-threatening complication of abdominal aortic reconstruction. Clinical presentation varies and treatment requires complex surgical repair associated with considerable morbidity and mortality. This retrospective study examines the contemporary management of SADF at a tertiary vascular surgical practice. Thirteen patients were managed for SADF between 2004 and 2014. Vascular and duodenal reconstructions were considered. Primary end points included bile leak, major complications, and mortality. Of the 13 patients presenting with SADF, 6 presented with luminal blood loss. During mean follow-up (632 days), the rate of major complication was 77%. Overall, 38% developed duodenal leak. All leaks occurred after graft explantation with extra-anatomic bypass, and the majority of these patients (80%) had no preceding history of acute gastrointestinal (GI) bleed. There were no leaks identified after duodenal exclusion with gastrojejunostomy. Patients that developed duodenal leak had longer mean intensive care unit length of stay (LOS; 7.0 vs. 2.3 days, P = 0.004), longer mean overall hospital LOS (36.6 vs. 18.5 days, P = 0.012), and greater late mortality (40% vs. 13%). There were 2 SADF-related deaths. Overall mortality trended higher in females (67% vs. 20%, P = 0.125) and those that presented without acute GI bleed (43% vs. 17%, P = 0.308). Surgical reconstruction for SADF results in major morbidity. Those presenting with acute GI bleed trended toward better outcomes than those without. Duodenal leak remains a serious complication. Duodenal exclusion may represent a more appropriate and conservative approach for management of the duodenal defect in select patients.

Secondary aortoduodenal fistula following endovascular repair of inflammatory abdominal aortic aneurysm due to Streptococcus anginosus infection: A case report and literature review

INTRODUCTIONAortoenteric fistula is a rare but very serious complication of both surgical and endovascular abdominal aortic reconstruction. Since the advent of endovascular abdominal aortic aneurysm repair (EVAR), 20 cases of aortoduodenal fistula associated with aortic stent grafts have been reported.1 However, only a handful has been reported following inflammatory abdominal aortic aneurysm repair. It most commonly presents with bleeding, usually from the upper gastro-intestinal tract. With recent advances in the screening, diagnosis and management of abdominal aortic aneurysms either surgically or through an endovascular approach, the diagnosis of an aortoduodenal fistula in patients with gastro-intestinal bleeding must be suspected and excluded. PRESENTATION OF CASEWe describe a case of secondary aortoduodenal fistula that occurred two and a half years following endovascular stent graft repair of an inflammatory abdominal aortic aneurysm. We also outline the emergency correction plan and the attempts at repair. DISCUSSIONThis case defies the general concept that patients with inflammatory abdominal aortic aneurysms are relatively immune to rupture. Although the presence of a peri-aneurysm thick inflammatory membrane decreases the possibility of rupture, these patients are more susceptible to other related complications such as aorto-enteric and aorto-caval fistulas.2 This case also demonstrates the peculiar presence of Streptococcus anginosus as the pathological organism leading to graft infection and subsequent fistula, as opposed to enterococci which are often found in endograft infection. CONCLUSIONAorto-enteric fistulas are associated with a grave prognosis. Early diagnosis is crucial and extra vigilance should be taken in cases of inflammatory AAA.

Fístula aorto-entérica secundária - a propósito de um caso clínico

The authors present a case report of a patient with previous history of a left aorto-femoral bypass complicated by infection, then submitted to partial resection of the prosthesis and femoro-femoral bypass, with subsequent transversostomy for fistula between the descendent colon, the loca of the removed prosthesis and the abdominal wall. After a few episodes of gastrointestinal bleeding with no conclusive investigation, a secondary aorto-duodenal fistula was suspected in the last abdominopelvic CT performed. The patient was submitted to laparotomy for abdominal aorta closure suture and axilo-“cross over” bypass. This is followed by a literary review of aorto-enteric fistulae.

ダメージコントロールが有効であった腹部大動脈－十二指腸瘻手術の1 例

ダメージコントロールが有効であった腹部大動脈－十二指腸瘻手術の1 例

Secondary aortoduodenal fistula in the duodenal bulb: role of side-viewing endoscopy

Secondary aortoduodenal fistula is an uncommon but life-threatening complication of aortic reconstructive surgery [1]. Here we report on the diagnosis of an aortoduodenal fistula using an atypical endoscopic method.

Secondary aortoduodenal fistula identified by ultrasonography.

A 73-year-old man underwent coronary artery bypass grafting, abdominal aortic aneurysm resection, and prosthetic implantation as a single procedure in 2002. His progress was favorable until April 2008, when he was admitted to our hospital with melena. B-mode ultrasonography revealed a 5-mm defect in the abdominal aorta at the graft anastomosis, and an umbilicated lesion was seen projecting between the posterior wall of the third part of the duodenum and the abdominal aorta. A color signal was noticed at this site on color Doppler ultrasonography, leading to the diagnosis of a secondary aortoduodenal fistula (ADF). We resected the inflammatory mass comprising the graft and the third part of the duodenum, and performed prosthetic re-implantation, omentopexy, and duodenojejunostomy. We could not find any previous reports of successful identification of secondary ADF using ultrasonography. When a patient with gastrointestinal hemorrhage following reconstructive aortic surgery is encountered in the emergency department, ultrasonography may be considered to be a useful modality in the diagnosis of secondary ADF.

Primary Aortoduodenal Fistula – A Rare Clinical Entity

Abdominal aortic aneurysm (AAA) is a very serious and rare communication between the lumen of the aorta and that of the duodenum. When such a fistula occurs in the absence of previous aortic aneurysm surgery, it is called a primary aortoduodenal fistula (PADF), a condition much less frequent than a secondary aortoduodenal fistula which occurs as a result of previous aortic aneurysm grafting. The diagnosis can be delayed due to the rare occurrence of the condition, non-specificity of abdominal signs, and frequent initial absence of records alerting the clinician to a known AAA, thereby resulting in increased morbidity and mortality. Salmon described the first case report of a PADF in 1843.1 Since then about 250 cases have been reported in literature.2–7 The incidence at autopsy is between 0.04% and 0.07%.4,7 The incidence of secondary aortoduodenal fistula is 0.5–2.3%.6 In this article we present a further case of PADF and discuss the pathophysiology, diagnosis and management of the condition, highlighting the fallibility of diagnostic investigations and the importance of having a high index of clinical suspicion.

Acutely Bleeding Aortoduodenal Fistula: Staged Endovascular and Open Surgical Repair

Secondary aortoduodenal fistula is an uncommon but potentially fatal complication that can occur after aortic reconstruction surgery and usually presents with upper gastrointestinal hemorrhage. Taking into account the accompanying multiple comorbidities of those patients, conventional open surgical repair carries with it significant mortality and morbidity rates. The purpose of this case report is to describe the successful combined endovascular and open surgical repair of an acutely ruptured aortoduodenal fistula in a 67-year-old male patient. Four months after the procedure, the patient remains well.

Secondary aortoduodenal fistula

Aorto-duodenal fistulae (ADF) are the most frequent aorto-enteric fistulae (80%), presenting with upper gastrointestinal bleeding. We report the first case of a man with a secondary aorto-duodenal fistula presenting with a history of persistent occlusive syndrome. A 59-year old man who underwent an aortic-bi-femoral bypass 5 years ago, presented with dyspepsia and biliary vomiting. Computed tomography scan showed in the third duodenal segment the presence of inflammatory tissue with air bubbles between the duodenum and prosthesis, adherent to the duodenum. The patient was submitted to surgery, during which the prosthesis was detached from the duodenum, the intestine failed to close and a gastro-jejunal anastomosis was performed. The post-operative course was simple, secondary ADF was a complication (0.3%-2%) of aortic surgery. Mechanical erosion of the prosthetic material into the bowel was due to the lack of interposed retroperitoneal tissue or the excessive pulsation of redundantly placed grafts or septic procedures. The third or fourth duodenal segment was most frequently involved. Diagnosis of ADF was difficult. Surgical treatment is always recommended by explorative laparotomy. ADF must be suspected whenever a patient with aortic prosthesis has digestive bleeding or unexplained obstructive syndrome. Rarely the clinical picture of ADF is subtle presenting as an obstructive syndrome and in these cases the principal goal is to effectively relieve the mechanical bowel obstruction.

Intra Vascular Ultra Sound: One More Tool to Diagnose Aorto-duodenal Fistula

The incidence of aorto-enteric fistula in the first 5 years after abdominal aortic replacement ranges from 0.3 to 2%. We present a clinical case in which all conventional diagnostic tools failed to demonstrate the aorto-enteric fistula. A 73 year-old male suffering intermittent episodes of melena without signs and symptoms of infection was repeatedly admitted at our institution. All conventional diagnostic tools failed to show the bleeding source. Precise diagnosis was obtained using intra vascular ultrasound (IVUS). IVUS allowed prompt diagnosis of the aorto-duodenal fistula and opened the way to its endovascular treatment.