Aortoenteric Fistula Research Articles

Endovascular management of mycotic aortic aneurysms- A 20-year experience from a single UK centre

To present the authors' experience of endovascular treatment of confirmed and presumed (microbiology negative) mycotic aortic aneurysms (MAA). Patients undergoing endovascular aortic repair were identified retrospectively from 1998 using the radiology information system and an internally kept database until 2018. The primary aim was to assess the technical success and peri-operative morbidity and mortality. The secondary aim was to assess progression of infection, re-interventions, late mortality, and correlation to antibiotic duration pre- and post-procedure. Thirty-four endovascular aortic procedures were performed for MAA, excluding aorto-enteric fistulas, inflammatory aneurysms, and infected grafts without a new aneurysm. Seventy-six percent of these were thoracic and 24% abdominal. The technical success was 100%. Additional procedures were undertaken in four patients with two requiring a further endovascular procedure. There were two inpatient aneurysm-related mortalities and no inpatient conversions to open repair. The 30-day re-admission and re-intervention rate was 0%. Blood cultures were positive in 45%. There were no secondary graft infections. This is the largest European single-centre study. It supports endovascular management of MAA as a lower-risk alternative to open surgery with the majority of patients presenting acutely, later in life and requiring emergency management.

Aortoenteric fistula: Case series from a tertiary center in Taiwan

AbstractAortoenteric fistula, a rare and catastrophic medical condition usually relevant to previous aortic surgery and other rare causes, is a disease that needs a multidisciplinary team including gastroenterologist, radiologist, and cardiovascular surgeon to deal with. Computed tomography with/without angiography is the choice of image study for diagnosis. Esophagogastroduodenoscopy also plays an important role in diagnosis. Exploratory laparotomy is usually mandatory because of difficulties in diagnosis and emergent condition. Aortic repair is the definite treatment and it could be done via open or endovascular surgery. From 2005 to 2017, total six patients who had the diagnosis of aortoenteric fistula (AEF) were collected from a tertiary center in Taiwan. Demographic data, diagnostic approach, treatment, and prognosis were all recorded. Among the six patients, the clinical presentations were gastrointestinal bleeding (GIB) (100%), abdominal pain (50%), and unstable hemodynamics (50%). Computed tomography angiography showed clues for AEF in four out of five patients. Four patients had definite diagnosis after open surgery. The survival time from initial presentation ranges from few hours to 29 months (median: 4.5 months). The most common manifestation of AEF is GIB. Due to its high mortality rate and difficult diagnosis, we should remind us of this rare disease for early diagnose and timely treatment.

In situ bypass and extra-anatomic bypass procedures result in similar survival in patients with secondary aortoenteric fistulas

ObjectiveThe optimal revascularization modality in secondary aortoenteric fistula (SAEF) remains unclear in the literature. The purpose of this investigation was to determine the revascularization approach associated with the lowest morbidity and mortality using real-world data in patients with SAEF. MethodsA retrospective, multi-institutional study of SAEF from 2002 to 2014 was performed using a standardized database. Baseline demographics, comorbidities, and operative and postoperative variables were recorded. The primary outcome was long-term mortality. Descriptive statistics, Kaplan-Meier survival analysis, and univariate and multivariate analyses were performed. ResultsDuring the study period, 182 patients at 34 institutions from 11 countries presented with SAEF (median age, 72 years; 79% male). The initial aortic procedures that resulted in SAEF were 138 surgical grafts (76%) and 42 endografts (23%), with 2 unknown; 102 of the SAEFs (56%) underwent complete excision of infected aortic graft material, followed by in situ (in-line) bypass (ISB), including antibiotic-soaked prosthetic graft (53), autogenous femoral vein (neoaortoiliac surgery; 17), cryopreserved allograft (28), and untreated prosthetic grafts (4). There were 80 patients (44%) who underwent extra-anatomic bypass (EAB) with infected graft excision. Overall median Kaplan-Meier estimated survival was 319 days (interquartile range, 20-2410 days). Stratified by EAB vs ISB, there was no significant difference in Kaplan-Meier estimated survival (P = .82). In comparing EAB vs ISB, EAB patients were older (74 vs 70 years; P = .01), had less operative hemorrhage (1200 mL vs 2000 mL; P = .04), were more likely to initiate dialysis within 30 days postoperatively (15% vs 5%; P = .02), and were less likely to experience aorta-related hemorrhage within 30 days postoperatively (3% aortic stump dehiscence vs 11% anastomotic rupture; P = .03). There were otherwise no significant differences in presentation, comorbidities, and intraoperative or postoperative variables. Multivariable Cox regression showed that the duration of antibiotic use (hazard ratio, 0.92; 95% confidence interval, 0.86-0.98; P = .01) and rifampin use at time of discharge (hazard ratio, 0.20; 95% confidence interval, 0.05-0.86; P = .03) independently decreased mortality. ConclusionsThese data suggest that ISB does not offer a survival advantage compared with EAB and does not decrease the risk of postoperative aorta-related hemorrhage. After repair, <50% of SAEF patients survive 10 months. Each week of antibiotic use decreases mortality by 8%. Further study with risk modeling is imperative for this population.

Primary Aortoesophageal Fistula: Is a High Level of Suspicion Enough?

Aortoenteric fistula (AEF) is a rare condition with a high mortality rate. AEFs are classified according to their primary and secondary causes, the former being less frequent. Primary AEFs occur in a native aorta and their causes include aneurysms, foreign bodies, tumours, radiotherapy and infection. The classic triad of aortoesophageal fistulas, a subtype of AEFs, are mid-thoracic pain and sentinel haemorrhage, followed by massive bleeding after a symptom-free interval.We present the case of a 41-year-old male patient who presented in the emergency room after successive episodes of abundant haematemesis. He was hypovolemic, hypothermic and acidotic at presentation. His medical history included an emergency room visit the week before with chest pain but no relevant anomalies on work-up, active intravenous drug use and chronic hepatitis.Esophagogastroduodenoscopy (EGD) showed a bulging ulcerated lesion suspicious for aortoesophageal fistula, confirmed by computed tomography (CT) angiography, which revealed a saccular aortic aneurysm with a bleeding aortoesophageal fistula. The patient underwent urgent thoracic endovascular aortic repair.The sentinel chest pain, leucocytosis and CT findings hinted at the presence of a mycotic aneurysm, despite the negative blood cultures. It was most likely caused by a septic embolus due to the patient’s risk factors. While a high level of suspicion for aortoesophageal fistula is needed to prompt a fast diagnosis, EGD and CT findings were crucial to establish it and allow a life-saving intervention. We conclude that chest pain cannot be disregarded in a patient aged 41 years with multiple comorbidities, despite normal work-up, to prevent a fatal outcome.LEARNING POINTSAortoesophageal fistula is a rare cause of severe upper gastrointestinal haemorrhage with a high mortality rate.Computed tomography angiography is diagnostic in most cases but a high level of suspicion is essential.Chest pain, a characteristic clinical symptom of aortoesophageal fistula, cannot be disregarded in a patient with multiple comorbidities, even in the presence of a normal electrocardiogram and chest x-ray.

Fístula aortoentérica: Espectro de hallazgos en tomografía computarizada multidetector

An aortoenteric fistula is an abnormal communication between the aorta and the gastrointestinal tract wall. The high mortality associated with this rare entity means it requires early accurate diagnosis. Aortoenteric fistulas are classified as primary when they develop on a native aorta that has not undergone an intervention and as secondary when they develop after vascular repair surgery.All radiologists need to be able to recognize the direct and indirect signs that might suggest the presence of an aortoenteric fistula. This article reviews the types of aortoenteric fistulas and their clinical and pathophysiological correlation, as well as the diagnostic algorithm, illustrating the most characteristic findings on multidetector computed tomography.

Recurrence of Aortoenteric Fistula after Endovascular Aortic Repair.

Aortoenteric fistula (AEF) after endovascular aortic repair (EVAR) is a rare complication, with only 32 cases reported previously. A 71-year-old man who presented with severe duodenal bleeding due to primary AEF (PAEF) underwent successful EVAR. Four years later, the AEF recurred because of dilatation of the aneurysm sac. He underwent emergent surgery, removal of the stent graft, and replacement of an artificial bifurcated graft with placement of a greater omental flap. EVAR for PAEF was an effective option for acute treatment, but it caused refistulization in the long term. EVAR should be considered as a bridge therapy to definitive surgery.

Strategy to avoid open surgical conversion after endovascular aortic aneurysm repair for patients with infrarenal abdominal aortic aneurysm.

PurposeOpen surgical conversion (OSC) is the last treatment option for patients with endovascular aneurysm repair (EVAR)failure. We investigated the underlying causes of EVAR failure requiring OSC and attempted to determine strategies to avoid OSC after EVAR.MethodsWe retrospectively reviewed the database of patients who underwent OSC after EVAR from 2005 to 2018 in a single institution. Twenty-six OSCs were performed in 24 patients (median age, 74.5 years; 79.2% of males) who had undergone standard EVAR. We investigated pre-, intra-, and postoperative computed tomography or angiographic images and outcomes of the OSCs.ResultsTwo main indications for OSC were persistent endoleak (50.0%) and endograft infection (EI) (38.5%). All 13 patients who underwent OSC due to endoleaks received EVAR outside of indications for use. Among 10 patients who underwent OSC due to EI, we found overlooked infection sources in 7 (70.0%) at the time of EVAR or during the surveillance period. OSC was performed at a median of 31.8 months (interquartile range, 9.4–69.8) after EVAR as an emergency (15.4%) or elective (84.6%) surgery. Aortic endograft was removed in 84.6% of cases (totally, 57.7%; partially, 26.9%), whereas it was preserved in 4 cases (15.4%). After 26 OSCs, 2 early deaths (7.7%) and 2 aortoenteric fistulae (7.7%) developed as major complications.ConclusionOSC after EVAR was associated with relatively higher perioperative morbidity and mortality. To avoid OSC after EVAR, we recommend careful assessment of coexisting infection sources and avoidance of EVAR for patients with especially unfavorable anatomy for EVAR, particularly the in proximal neck.

Primary aortoduodenal fistula without an abdominal aortic aneurysm: A case report

Introduction. Aortoenteric fistula is a communication between the aorta and segments of the gastrointestinal tract. Primary aortoduodenal fistula is an extremely rare cause of gastrointestinal bleeding associated with a high mortality rate. Case Report. We report a case of a 63-year-old man admitted due to abdominal pain lasting for a week. Abdominal ultrasound and computed tomography angiography revealed an aortoduodenal fistula without an aortic aneurysm. Conclusion. This case is an example of a rare cause of gastrointestinal bleeding, as well as presentation of aortoduodenal fistula that was not caused by an abdominal aortic aneurysm.

Aortoenteric fistula after endovascular aortic repair of infected abdominal aortic aneurysm

Secondary aortoenteric fistula is a rare yet fatal condition that may occur as a complication after abdominal aortic aneurysm repair. Here, we report a case of a 66-year-old male with abdominal discomfort and intermittent fever at 5 years after endovascular aortic repair of an infected abdominal mycotic aneurysm. Surgical treatment with extra-anatomic bypass for lower body revascularization, followed by exploratory laparotomy with explantation of the infected graft and aortic tissue and repair of the duodenum were performed. The patient was rescued from the septic condition and discharged uneventfully 2 months postoperatively.

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.

Rare cause of upper gastrointestinal bleeding due to primary aortoesophageal fistula - a case report

Background: The incidence of acute upper gastrointestinal bleeding (UGIB) has declined over the recent decades, and nowadays, due to improved endoscopic treatment options, only 2.6% of the patients with UGIB need additional surgical or angiographic intervention. In this report, we present the case of UGIB, refractory to endoscopic treatment, caused by a primary aortoesophageal fistula. Case Presentation: A 72-year-old man with acute UGIB was referred to our clinic after unsuccessful endoscopic and surgical treatment in an external hospital. On admission, the patient showed prolonged hemorrhagic shock and abdominal compartment syndrome. An immediately conducted thoracoabdominal CT scan revealed a penetrating aortic ulcer of the descending aorta and the patient was transferred to the OR to undergo laparotomy. After confirmation of a primary aortoesophageal fistula as the origin of hemorrhage, an aortic stent graft was successfully placed to occlude the lesion. Despite severe blood loss and prolonged hemorrhagic shock, the patient recovered quickly and could be discharged on the 18th postoperative day. Conclusion: Primary aortoenteric fistula is an uncommon clinical condition with a high mortality requiring an interdisciplinary treatment approach.

Long Term Results of In Situ Reconstruction with Cryopreserved Arterial Allografts for Secondary Aorto Enteric Fistulas

Introduction - Secondary aorto enteric fistula (SAEF) is a rare complication (0.3% to 1.6%) with a high morbidity rate. The infection rate of aortic vascular graft is described between 0.6% and 3%. SAEF represents 20 to 45% of these vascular graft infections. The treatment can be performed by different methods and in various steps. The choice of the treatment remains controversial. The objective of our study was to evaluate the long term results of the treatment of secondary aorto enteric fistulas by in situ reconstruction with cryopreserved arterial allograft. Methods - Between 1995 and 2015, 30 patients (mean age: 75 years, 27 males, 3 females) were surgically treated for SAEF in 3 French university hospitals. 16 patients were initially treated for infrarenal abdominal aortic aneurysm and 14 for occlusive aortic disease. Mean time before occurrence of SAEF was 72 months. Surgical treatment consisted of total graft excision and in situ reconstruction with cryopreserved arterial allografts as well as digestive tract reconstruction. Data were collected retrospectively. Primary endpoint was overall survival at 12 and 36 months. Secondary endpoints were primary patency, reinfection rate, postoperative morbidity and limb salvage rate. Results - Survival rate at 12 and 36 months were respectively 70% and 65%. Mean follow up was 39 months (range: 1-194). The 30-day postoperative mortality rate was 23%. Primary patency rate at 1 year and 5 years were 95% and 86%, respectively. There were 2 allograft thromboses. Limb salvage rate was 100%. There was no recurrence of aorto enteric fistula. Reinfection occurred in 2 patients (7%). The most frequent organisms identified were Candida albicans (36%) and Escherichia coli (32%). There were no bacterial findings for 5 patients (17%). The fistula was found between the graft anastomosis and the duodenum in 87% of the patients. Digestive tract treatment was performed with duodenal resection for 13 patients (47%), duodenal suture for 12 (40%), intestinal resection for 5 (17%) and 6 stoma creations. Conclusion - The long term results of SAEF treated by in situ reconstruction with cryopreserved arterial allografts were satisfactory. The occurrence of SAEF threatens the vital prognosis of the patient and long term surveillance is mandatory.

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.

Cryopreserved Arterial Allografts for In-Situ Reconstruction of Abdominal Aortic Native or Secondary Graft Infection

Introduction - Native and aortic graft infection is rare but represents one of the most life-threatening complications in vascular surgery. The gold standard treatment includes excision of the infected aorta or graft and in-situ reconstruction using autologous veins, silver or antibiotic coated prosthesis, or cryopreserved arterial allografts (CAA). The optimal choice between these materials still remains debated. CAA has emerged as a good solution having the advantage of higher resistance to infection1,2 but also the disadvantages of potential degeneration and uncertain availability. Our aim was to evaluate the early and long-term outcome and identify predictors of mortality as regards cryopreserved arterial allografts used for in-situ reconstruction of abdominal aortic native or secondary graft infection. Methods - We retrospectively included 71 patients (mean-age: 65.2 years (range: 41-84, men: 91.5%) treated for abdominal aortic native or secondary graft infection (65 prosthetic graft infections, 16 of them had secondary aortoenteric fistula, 2 venous graft infections and 4 mycotic aneurysms) via in-situ reconstruction with CAA in two French University Hospitals, from 2001 to 2016. The cryopreservation protocol was identical in both centers (-140°C). Early (<30 days) and late (>30 days) mortality and morbidity, reinfection and CAA patency were assessed. A CT-scan was performed in all survivors. Survival was analyzed with the Kaplan-Meier method. Univariate analyses were performed with the log-rank tests and multivariate analysis with the Cox regression model. Results - Mean follow-up was 45 months (0-196). Early postoperative mortality rate was 14% (10/71). Early postoperative CAA-related mortality rate was 2.8% (2/71), both patients died from proximal anastomotic rupture on postoperative day 4 and 15. Early CAA-related reintervention rate was 5.6% (4/71), all had an anastomotic rupture and 2 were lethal. Early postoperative reintervention rate was 15.5% (11/71). Intraoperative bacteriologic samples were positive in 56.3% and 31% had a sole micro-organism. Escherichia coli was more frequently identified in the secondary aortoenteric fistula and Staphylococcus epidermidis in the infected prosthesis. Late CAA-related mortality rate was 2.8%: 1 septic shock at 2 months and 1 proximal anastomosis rupture at 1 year. Survival at 1, 3 and 5 years were 75%, 64% and 54%, respectively. Multivariate analysis identified type 1 diabetes (HR=2.49 [1.05–5.88]; P=0.04) and ASA (American Society of Anesthesiologists) score 4 (HR=2.65 [1.07–6.53], p=0.035) as predictors of mortality after in-situ CAA reconstruction. Reinfection rate was 4% (3/71). Late CAA-related reintervention rate was 12.7% (9/71): 1 proximal anastomotic rupture, 5 CAA branch stenosis/thrombosis, 1 ureteral-CAA branch fistula and 2 distal anastomosis false aneurysms. Primary patency at 1, 3 and 5 years were 100%, 93% and 93%, respectively. Assisted primary patency at 1, 3 and 5 years were 100%, 96% and 96%, respectively. No aneurysms or dilatation were observed. Conclusion - The prognosis of native or secondary aortic infections is poor. Aortic in-situ reconstruction with CAA offers acceptable early and late results. Patients with type 1 diabetes and ASA score 4 are at higher risk of mortality.

In the Current Era of Endovascular Surgery, What is the Role of Axillofemoral Bypass?

Introduction - Nowadays, axillofemoral bypass (AxFB) is viewed as an end-of-line solution for lower limb revascularization, owing to its classically described poor long-term patency and recent advances in endovascular surgery. There is a marked difference in patient profiles in published series of AxFB, reflecting changing procedures indications. The objective of this study is to determine the contemporary profile of patients treated with AxFB and their outcome. Methods - Patients who underwent AxFB surgery in a tertiary hospital from April 2011 to December 2017 were identified. Surgical indication, primary patency, major amputation and death rates were recorded. Patients were grouped in:-Bypass configuration: axillouni vs axillobifemoral;-Previous vascular surgery status: first revascularization procedure vs reintervention;-Primary vascular disease: aortoiliac occlusive disease vs aneurysmal disease,-Emergency character of procedure: urgent (initiated less than 24hours from patient presentation) vs planned (more than 24hours from patient presentation). Groups were compared using Kaplan-Meier survival analysis. Results - 56 patients were included. 44 (78,6%) underwent axillobifemoral bypass; remaining patients underwent axillounifemoral bypass. Median age was 68,18±9,59 years; 94,6% were male. The most prevalent cardiovascular risk factors were HTA (77%) and history of smoking (76%). Primary vascular disease was aneurysmal in 14 patients (25%). The remaining group had aortoiliac occlusive disease. AxFB was an urgent procedure in 11 patients (19,6%). In 30 patients (53,6%), AxFB was the first revascularization performed. Indications for procedure on this group were aorto-iliac occlusive disease (25; 83,3%) and AA thrombosis (5; 16,7%). In patients previously submitted to revascularization (26; 46,4%), the most common previous procedures were aortobifemoral bypass (12; 46,2%), femoro-femoral bypass (12; 46,2%) and EVAR (9; 34,6%). Indications for AxFB on this group were: prosthesis thrombosis (17; 65,4%), secondary aorto-enteric fistulae (7; 26,9%) and prosthesis infection (2; 7,7%). Global primary patency of AxFB was 91,5±4,1% at 1 month, 74,8±7,6% at 1 year, and 56,1±12,8% at 5 years (Fig.1). Group survival analysis showed superior primary patency in aneurysmal disease group (p=0,063), and after urgent procedures (p=0,113). Previous vascular surgery and bypass configuration did not affect long-term primary patency. No patient with aneurysmal disease required major amputation during follow-up. In primary occlusive disease group, 83,4±5,7% patients were free-of-amputation at 1 month, 77,2±6,8% at 1 year and 5 years. Amputation rates were similar regardless previous vascular surgery status, bypass configuration and urgency character of procedure. Median time of survival was 5,1±1,1years. Patients who underwent AxFB had a survival rate of 76,8±5,6% at 1 month, 64,7±6,6% at 1 year, and 50,0±7,8% at 5 years. Survival rates were similar regardless bypass configuration and primary vascular disease. However, patients whose AxFB was a vascular reintervention or an urgent procedure had significant worse long-term survival (p=0,042 and p=0,017, respectively). Conclusion - Axillofemoral bypass, although being an increasingly uncommon procedure, still allows acceptable rates of patency and limb salvage. As patients with aortoiliac disease usually have multiple comorbidities and a short life-expectancy, axillofemoral bypass is attractive owing to its less invasive character.

Surgical Management for Secondary Aortoduodenal Fistula

Aortoenteric fistulas (AEFs) are uncommon but life-threatening conditions carrying a high mortality rate. This is defined as an abnormal connection between the aorta and the lumen of the gastrointestinal tract. There are two known forms of AEF, primary and secondary. Primary is most often the result of compression of an abdominal aortic aneurysm against the intestines, whereas secondary is due to an erosion of an aortic prosthetic graft into the surrounding gastrointestinal structures. The relative incidence of primary AEF ranges from 0.1 to 0.8%, and secondary from 0.4% to 2.4%. Mortality rates after surgical treatment of secondary AEFs range from 14% to 70%. This report describes the surgical approach of a secondary aortoduodendal fistula after placement of end to side aortobifemoral bypass for claudication symptoms in a 58-year-old female presenting with gram-negative bacteremia.

1664 A Herald Bleed: A Case Report of an Aortoenteric Fistula Causing an Acute Lower Gastrointestinal Bleed

INTRODUCTION: Aortoenteric fistula (AEF) is a rare, life-threatening condition with an incidence of 0.007/million. Primary AEF arises de novo, secondary AEF (SAEF) occurs following abdominal aortic aneurysm (AAA) repair. Majority of AEF’s involve the duodenum, due to proximity to the aorta. It may present as an exsanguinating herald GI bleed, associated with high mortality rates. SAEF has a 45.8% mortality rate in the first month. CASE DESCRIPTION/METHODS: A 66-year-old female presented with sudden onset of large volume bright red blood per rectum (BRBPR). She denied any prior episodes of GI bleed, alcohol or NSAID use and had never had prior endoscopy. She mentioned cholecystectomy and hysterectomy as her only surgical interventions. On examination she was hemodynamically unstable, lethargic and had a midline abdominal scar. Digital rectal exam showed BRBPR. Her lab workup showed: Hgb 9.5, Hct 29%, platelets 147000, INR 1. An emergent EGD was negative. Colonoscopy showed a 5 cm, pulsatile submucosal mass with an actively bleeding ulcerated area. Epinephrine was injected for temporary hemostasis. A hemoclip was placed to mark the site for potential embolization, as the lesion was not amenable for definitive endoscopic intervention. A stat CT angiogram of the abdomen and pelvis revealed a large left external iliac artery (LEIA) pseudoaneurysm in the region of the clip placed during colonoscopy. Vascular surgery emergently placed a LEIA stent. It appeared the patient had an open aorto-bi-iliac bypass 15 years ago for a AAA which resulted in the development of SAEF. She did well post operatively. DISCUSSION: AEF is important to consider in older patients who present with large volume hematochezia. The presence of prior signs of abdominal surgery should raise suspicion for SAEF as it is difficult to diagnose because of its rarity. The commonest symptom of SAEF is gastrointestinal bleeding. Other symptoms are fever, sepsis, pulsating abdominal or groin mass, abdominal or back pain. CT and GI endoscopy are frequently used for diagnosis. Without treatment AEF often proves to be fatal. Treatment of AEF includes volume resuscitation, antibiotics, and aortic repair. Given our patient's bleed with tenuous clinical status, large body habitus, medical comorbidities, poor functional status as well as previous aorto-bi-iliac bypass, decision was made to approach the pseudoaneurysm endovascularly, despite possible presence of vessel-enteric fistula, as she was deemed unstable for an open approach.

1967 Unexplained Massive Recurrent Upper GI Bleeding: A Case of Missed Connection

INTRODUCTION: Erosion of an aortic prosthetic graft into the surrounding gastrointestinal structures leads to formation of Aortoenteric fistula (AEF). It occurs after months to years after aortic surgery and may be related to graft infection and can result in torrential Gl bleeding. Here we present a case of recurrent GI bleeding, the cause of which initially remained obscure despite repeated endoscopies. CASE DESCRIPTION/METHODS: 61 y old male with PMH of peripheral vascular disease and femoropopliteal bypass on ASA and Eliquis presented with 3 days of passing black-tarry stools and dizziness. Initial hemoglobin was 7 gm/dL (normal baseline). Urgent EGD up to 2nd part of duodenum revealed clot in the stomach without any lesion or source of bleeding. EGD was repeated the next day due to ongoing melena, which again was nonrevealing. CTA also did not show any active bleeding. Eliquis was discontinued and the patient was discharged. 2 days later, he presented with ongoing melena and dizziness. EGD, however, this time revealed aortic graft eroding into 3rd part of the duodenal wall. He was transferred to a tertiary care center for repair of the fistula. DISCUSSION: AEF is an uncommon but life-threatening complication of aortic reconstructive surgery. Due to the anatomic proximity, most cases involve the duodenum, with the proximal suture line of an aortic prosthesis. It is imperative to inquire about the history of aortic reconstruction patients presenting with Upper GI bleeding, as these patients are considered to have an AEF until proven otherwise. In our case, the remote history of aortic reconstructive surgery was not put in the clinical perspective and aortic graft was overlooked on the CT scan. Both MRI and CT can fail to diagnose AEF and EGD has 50% sensitivity. Endoscopy should include the fourth portion of the duodenum. Prompt recognition and repair of fistula in highly critical for patient survival.

3210 Aortoenteric Fistula—Rare, Deadly and Obscure

INTRODUCTION: Small-bowel bleeding comprises a majority of obscure gastrointestinal bleeding, and is caused by various diseases. For its diagnosis, history-taking, physical examination, diagnostic testing such as cross-sectional imaging, followed by videocapsule endoscopy and deep enteroscopy are all used according to the severity of hemorrhage and patient condition. CASE DESCRIPTION/METHODS: A 74 year old male with an open AAA repair, CKD stage 3, diverticulosis, and ongoing overt obscure GI bleeding × 1.5 years s/p segmental small bowel resection was admitted for an episode of rectal bleeding with hemodynamic instability. He had innumerable upper endoscopies, colonoscopies, video capsule endoscopies and intraop enteroscopy with no clear etiology and had gotten over 70 units of packed RBCs. Records revealed He underwent repeat endoscopy and colonoscopy, but a video capsule endoscopy showed active bleeding in the sigmoid likely from diverticulosis and venous ectasias seen on CTA. He underwent sigmoid resection but bleeding recurred. He then underwent a provoked angiography which was normal. He continued to have bleeding episodes which was characterized by large volume hematochezia and hemodynamic instability. After extensive discussion he underwent a loop ileostomy to determine exact source of his bleeding (small bowel versus colon). Unfortunately 24 hours after surgery, he became unresponsive and developed large volume hematemesis which led to his demise. An autopsy was performed and showed a secondary aortoenteric fistula. This is perhaps one of the only are reported cases of AEF presenting as an obscure GI bleed. DISCUSSION: Development of an aortoenteric fistula (AEF) is a devastating and life-threatening condition, which is as difficult to diagnose as it is to treat. Fortunately, it is rare, most commonly seen as a delayed complication of aortic reconstruction. Two types are recognized: primary and secondary. Primary fistulas occur de novo between the aorta and bowel, most commonly duodenum. Secondary fistulas occur between an aortic graft and segment of bowel. Diagnosis of AEF requires a high index of suspicion in patients who present with either signs of infection or gastrointestinal hemorrhage.

Modern Management of Arterio-Visceral/Arterio-Lumenal Fistulas - Selection of Representative Clinical Situations and Cases

Circuits of abdominal arteries to adjoining lumenal organs, especially in triggering circumstances, are rare diseases that are increasingly evident in endovascular therapies and complex viscero-/tumor-surgical procedures with subsequent lengthy adjuvant therapies. Their care is a challenge and involves frequent complications and mortality. Narrative overview on the basis of current scientific references and our clinical and surgical experience. Uretero-arterial fistulas are usually associated with recurrent and intermittent gross haematuria. The diagnostic test of choice continues to be angiography with the potential for endovascular therapy, which has displaced open surgical procedures due to minimal invasiveness, low morbidity and mortality. Aorto-oesophageal fistulas may result from underlying infectious and malignant diseases as well as open and endovascular therapies of the aorta. Multi-line contrast CT of the thorax/abdomen and gastroscopy have priority in diagnostic testing. Endovascular procedures can only be understood as bridging procedures, and only the removal of prostheses with aortic and gastrointestinal reconstruction are curative. Aorto-enteric fistulas are secondary complications of open and endovascular aortic surgery. Contrast enhanced multi-line CT has high sensitivity and specificity. In contrast, open surgical therapy involves in-situ reconstruction of extra-anatomical reconstructions with aortic ligature. Endovascular therapy is reserved for exceptional cases. Inflammatory aneurysms of visceral arteries may be associated with adjacent inflammatory processes, most commonly pseudoaneurysms. The most suitable diagnostic procedure is contrast-enhanced thin-film CT angiography. The treatment of choice is endovascular ablation using covered stents or embolisation. Arterio-visceral/arterio-lumenal fistulas are similar in pathogenesis, predisposing factors and clinical symptoms. An interdisciplinary consultation is employed to identify individualised therapy. Endovascular/interventional procedures are safe and effective, and open surgical rehabilitation is mostly curative.