Aorta-cameral fistulas: Spectrum of CT findings and review

Aorto-cameral fistula (ACF) is an uncommon entity, defined as an abnormal communication between the aorta and a cardiac chamber. The most common causes include ruptured sinus of Valsalva aneurysm, infective endocarditis, traumatic injury, aortic dissection, or rarely can be iatrogenic in nature. While smaller communications may initially be asymptomatic, the natural course of these connections is generally refractory heart failure as they do not spontaneously heal. Larger fistulas can be life threatening with high mortality rates, and therefore once recognized, surgery is generally considered the treatment of choice. Diagnosis, however, can be challenging, and various imaging modalities are often used for diagnosis. This review highlights common underlying etiologies, clinical manifestations, and radiologic imaging appearances of ACF to each of the cardiac chambers of this uncommon, but clinically important entity, with emphasis on CT.     

Unusual fistulas and connections in the cardiovascular system: A pictorial review

A fistula is an abnormal vascular connection leading to diversion of blood from a high resistance arterial circuit to low resistance venous circuit. Coronary artery fistulas are abnormal communications of the coronary artery with a chamber of the heart, or with any segment of systemic or pulmonary circulation, bypassing the myocardial capillaries. Other unusual fistulas include connection between aorta and the right atrium/superior vena cava, aorta and the inferior vena cava or between a coronary artery bypass graft and a cardiac vein. Abnormal connections also include origin of the coronary artery from the pulmonary artery. In this article, we review the imaging, particularly computed tomography and magnetic resonance imaging of unusual fistulas and connections involving the cardiovascular system, particularly the coronary arteries and the aorta.     

Computed tomography diagnosis of a primary aortoduodenal fistula in a patient with a partially thrombosed abdominal aortic aneurysm

Primary aortoenteric fistula is a rare but fatal cause of gastrointestinal bleeding and requires urgent intervention. A high index of clinical suspicion in conjunction with imaging is required because a favorable outcome relies on prompt diagnosis. The primary forms of aortoduodenal fistulas are nearly always associated with abdominal aortic aneurysm, mostly atherosclerotic. Technological advances in imaging, particularly computed tomography (CT), play a pivotal role in the preoperative detection of these fistulas. We report the case of a 76-year-old man who was diagnosed with a large abdominal aortic aneurysm with associated contained rupture and suggestion of an aortoduodenal fistula on CT. This case demonstrated the effectiveness, ease, and low cost of the preoperative evaluation and documentation of a primary aortoduodenal fistula using CT scans.     

Cholecystocolonic fistula diagnosed with CT-intravenous cholangiography

Cholecystoenteric fistulas are often not diagnosed preoperatively and delineation of fistula can have an influence on surgical planning. We report a case of cholecystocolonic fistula diagnosed preoperatively using CT-i.v. cholangiography and review the published reports.     

Imaging Findings of Coronary Artery Fistula in Children: A Pictorial Review

Coronary artery fistula, defined as an abnormal communication between the coronary arteries and a cardiac chamber (most commonly) or a thoracic great vessel, may result in hemodynamically significant problems due to vascular shunting in children. Echocardiography, cardiac catheterization, cardiac MRI, and cardiac CT may be used to evaluate coronary artery fistula in children. Recently, CT has played a pivotal role for the accurate diagnosis of coronary artery fistula in children. Surgical or interventional treatment is performed for hemodynamically significant coronary artery fistulas. In this pictorial review, the detailed imaging findings of coronary artery fistula in children are described.     

The persistent trigeminal artery: development, imaging anatomy, variants, and associated vascular pathologies

The persistent trigeminal artery (PTA) is the most common and most cephalad-located embryological anastomosis between the developing carotid artery and vertebrobasilar system to persist into adulthood. As such, it is frequently reported as an incidental finding in computed tomography angiography and magnetic resonance angiography studies. Here, we review the embryology, anatomy, and angiographic imaging findings, including important variants of this commonly encountered cerebrovascular anomaly (reported incidence of PTA/PTA variants ranges from 0.1% to 0.76%). Further, the aim is to present the range of associated arterial anomalies or syndromes, as well as pathologies that are associated with a PTA: aneurysms, trigeminal cavernous fistulas, and trigeminal nerve compression. Besides summarizing the risks and clinical presentation of such pathologies, their management is discussed with endovascular strategies mostly being the primary choice for aneurysms and trigeminal cavernous fistulas. Symptomatic trigeminal nerve compression can be treated with microvascular decompression surgery. As an illustrative example, a case of a trigeminal cavernous fistula on a PTA variant is included, mainly to emphasize the importance of understanding the variant anatomy for treatment planning in such pathologies. Finally, recommendations on how to manage patients with PTA-associated vascular pathologies are advanced.     

Vesicouterine fistula associated with placenta percreta

Vesicouterine fistulas are uncommon acquired urogenital fistulas. A case of a vesicouterine fistula associated with placenta percreta is presented.     

Vesicouterine fistula associated with placenta percreta

Vesicouterine fistulas are uncommon acquired urogenital fistulas. A case of a vesicouterine fistula associated with placenta percreta is presented.     

Preoperative MR imaging of anal fistulas: Does it really help the surgeon?

PURPOSE: To evaluate the accuracy of magnetic resonance (MR) imaging with a quadrature phased-array coil for the detection of anal fistulas and to evaluate the additional clinical value of preoperative MR imaging, as compared with surgery alone. MATERIALS AND METHODS: Fifty-six patients with anal fistulas underwent high-spatial-resolution MR imaging. Twenty-four had a primary fistula; 17, a recurrent fistula; and 15, a fistula associated with Crohn disease. MR imaging findings were withheld from the surgeon until surgery ended and verified, and surgery continued when required. RESULTS: MR imaging provided important additional information in 12 (21%) of 56 patients. In patients with Crohn disease, the benefit was 40% (six of 15); in patients with recurrent fistulas, 24% (four of 17); and in patients with primary fistulas, 8% (two of 24). The difference between patients with or without Crohn disease and between patients with a simple fistula versus the rest was significant (P <.05). The sensitivity and specificity for detecting fistula tracks were 100% and 86%, respectively; abscesses, 96% and 97%, respectively; horseshoe fistulas, 100% and 100%, respectively; and internal openings, 96% and 90%, respectively. CONCLUSION: High-spatial-resolution MR imaging is accurate for detecting anal fistulas. It provides important additional information in patients with Crohn disease-related and recurrent anal fistulas and is recommended in their preoperative work-up.     

MR angiography of dural arteriovenous fistulas: diagnosis and follow-up after treatment using a time-resolved 3D contrast-enhanced technique

BACKGROUND AND PURPOSE: Digital subtraction angiography (DSA) is the method of reference for imaging of dural arteriovenous fistula (DAVF). The goal of this study was to analyze the value of different MR images including 3D contrast-enhanced MR angiography (MRA) with a high temporal resolution in diagnostic and follow-up imaging of DAVFs. MATERIALS AND METHODS: A total of 18 MR/MRA examinations from 14 patients with untreated (n=9) and/or treated (n=9) DAVFs were evaluated. Two observers assessed all MR and MRA investigations for signs indicating the presence of a DAVF, for fistula characteristics such as fistula grading, location of fistulous point, and fistula obliteration after treatment. All results were compared with DSA findings. RESULTS: On time-resolved 3D contrast-enhanced (TR 3D) MRA, the side and presence of all patent fistulas (n=13) were correctly indicated, and no false-positive findings were observed in occluded DAVFs (n=5). Grading of fistulas with this imaging technique was correct in 77% and 85% of patent fistulas for both readers, respectively. On T2-weighted images, signs indicative of a DAVF were encountered only in fistulas with cortical venous reflux (56%), whereas on 3D time-of-flight (TOF) MRA, most fistulas (88%) were correctly detected. In complete fistula occlusion, false-positive findings were encountered on both T2-weighted images and on TOF MRA images. CONCLUSION: In this study, TR 3D MRA proved reliable in detecting DAVFs and suitable for follow-up imaging. The technique allowed--within limitations--to grade DAVFs. Although 3D TOF MRA can depict signs of DAVFs, its value for follow-up imaging is limited.     

Successful endovascular treatment of aortoenteric fistula secondary to eroding duodenal stent

Aortoenteric fistulas are characterized as either primary or secondary on the basis of their cause. Most aortoenteric fistulas occur between the aorta and duodenum and are a rare but well-known cause of catastrophic gastrointestinal hemorrhage. Conventional treatment of aortoenteric fistulas uses bypass grafting and aortic ligation, but endovascular treatments have become more common. The authors describe the successful endovascular repair of a primary aortoenteric fistula caused by eroding duodenal stent.     

A Rare Case of Jejunal Arterio-Venous Fistula: Treatment with Superselective Catheter Embolization with a Tracker-18 Catheter and Microcoils

Arterio-venous fistulas may develop spontaneously, following trauma or infection, or be iatrogenic in nature. We present a rare case of a jejunal arterio- venous fistula in a 35-year-old man with a history of pancreatic head resection that had been performed two years previously because of chronic pancreatitis. The patient was admitted with acute upper abdominal pain, vomiting and an abdominal machinery-type bruit. The diagnosis of a jejunal arterio-venous fistula was established by MR imaging. Transfemoral angiography was performed to assess the possibility of catheter embolization. The angiographic study revealed a small aneurysm of the third jejunal artery, abnormal early filling of dilated jejunal veins and marked filling of the slightly dilated portal vein (13–14 mm). We considered the presence of segmental portal hypertension. The patient was treated with coil embolization in the same angiographic session. This case report demonstrates the importance of auscultation of the abdomen in the initial clinical examination. MR imaging and color Doppler ultrasound are excellent noninvasive tools in establishing the diagnosis. The role of interventional radiological techniques in the treatment of early portal hypertension secondary to jejunal arterio-venous fistula is discussed at a time when this condition is still asymptomatic. A review of the current literature is included.Fax 0041 31 6324874     

Imaging of Anal Fistulas: Comparison of Computed Tomographic Fistulography and Magnetic Resonance Imaging

The primary importance of magnetic resonance (MR) imaging in evaluating anal fistulas lies in its ability to demonstrate hidden areas of sepsis and secondary extensions in patients with fistula in ano. MR imaging is relatively expensive, so there are many healthcare systems worldwide where access to MR imaging remains restricted. Until recently, computed tomography (CT) has played a limited role in imaging fistula in ano, largely owing to its poor resolution of soft tissue. In this article, the different imaging features of the CT and MRI are compared to demonstrate the relative accuracy of CT fistulography for the preoperative assessment of fistula in ano. CT fistulography and MR imaging have their own advantages for preoperative evaluation of perianal fistula, and can be applied to complement one another when necessary.     

Iliocaval arteriovenous fistula presenting with multiple organ failure

Iliac arteriovenous fistulas are an uncommon condition, which may be spontaneous or traumatic in nature. Such fistulas classically present with a triad of high-output cardiac failure, pulsatile abdominal mass with a bruit and unilateral leg ischaemia or venous congestion. We describe a case of an iliocaval fistula secondary to rupture of a common iliac artery aneurysm, with an unusual presentation of multiple organ failure, masquerading as sepsis. We describe the CT findings of iliocaval fistula, which was the means of diagnosis in this study.     

Congenital broncho-oesophageal fistula in the adult

Five patients with congenital broncho-oesophageal fistula confirmed by fistulectomy are presented. Clinical symptoms were chronic or recurrent pulmonary infection, and three patients experienced coughing after swallowing. Pre-operative oesophagograms demonstrated broncho-oesophageal fistulas in all five patients. The fistulous communications were from the lower oesophagus to segmental bronchi of the lower lobe and to the left main bronchus. The fistulas showed smooth marginated serpentine margins with areas of internal trabeculation, and in two patients the fistulas communicated with anomalous bronchi. One patient had anomalous bronchi and subsequently underwent lobectomy which showed microscopic findings of intralobar sequestration. The oesophagus showed localized tenting with its apex to the fistula and mild ipsilateral displacement in four patients.     

放射性胸腔胃-气道瘘的影像学诊断与介入治疗

目的：探讨放射性胸腔胃-道瘘的影像学特征及其介入治疗方法。方法：回顾性分析7例具有完整临床资料的胸腔胃-气道瘘的口服碘水造影及CT表现；X线监视下，5枚长管状、4枚气管-主支气管分支型覆膜内支架置人气道封堵瘘口。结果：口服碘水造影显示胸腔胃-气管瘘3例，胸腔胃-隆突瘘1例。胸腔胃-左主支气管瘘2例，胸腔胃-右主支气管瘘1例；cr检查详细观察胸部情况，了解瘘与临近结构的详细解剖，测量气管／支气管内径。气道覆膜内支架置人气道完全封堵了瘘口，即刻消除呛咳症状，有效控制肺部感染。患者生活质量得以提高。结论：根据口服碘水造影和螺旋CT象，结合病史可以诊断放射性胸腔胃-气道瘘；置人气道覆膜内支架封堵瘘口操作简单、安全、近期疗效明显，是一项值得推广的新技术。     

肛瘘磁共振成像:探讨自制可调节肛肠水囊在肛瘘分级中的价值

目的:探讨普通MR成像中使用自制可调节肛肠水囊在肛瘘患者分级中的应用价值.方法:18例经手术证实的肛瘘患者于使用自制可调节肛肠水囊前、后均各行一次MRI检查.序列包括T_1 WI横断位和冠状位、T_2 W SPAIR横断位,冠状位及矢状位.放置水囊前后比较瘘管末端位置,并且对瘘管、内口、分支及脓腔进行计数,同时观察瘘管走行.所获结果被用于评估肛瘘MR诊断分级,并同时与手术结果相对照.结果:18名肛瘘患者MRI检查共发现瘘管31根、内口22个、分支19根以及脓腔10个.使用水囊前后MRI对瘘管末端位置的显示有显著不同(χ~2=5.56,P<0.05).使用水囊前,MR显示1例1级低位单纯线形括约肌内肛瘘,1例低位和2例高位2级括约肌内肛瘘伴脓肿或分支,1例3级高位经括约肌肛瘘,6例4级经括约肌肛瘘伴脓肿或分支,其中5例为高位,1例为低位,2例5级高位肛提肌上和经肛提肌肛瘘,另有5例无法确定;使用水囊后,2级高位括约肌内肛瘘伴脓肿或分支上升为3例,4级低位经括约肌肛瘘伴脓肿或分支上升至2例,高位上升至7例,另有1例无法确定,余小变.使用水囊前后,M RI对肛瘘分级与手术的相符率分别为72%(13例)和94%(17例).结论:通过使用自制町凋节肛肠水囊,普通M RI能够获得更多有关瘘管及其走行的信息,有助于肛瘘患者的分级.     

Delayed diagnosis of post-traumatic arteriovenous fistula from trip wire-detonated booby trap in Vietnam.

Traumatic arteriovenous fistulas are very common, especially with penetrating injuries. Undiagnosed traumatic arteriovenous fistulas for long periods, as in this case, however, are less frequent because the patient often experiences clinical manifestations associated with arteriovenous shunting. This patient denied any history of problems that might be associated with this arteriovenous shunting. He was operated on for the arteriovenous fistula and had an uneventful postoperative course.