Acquired gastrointestinal fistulas: classification, etiologies, and imaging evaluation

Interventional radiologic management and treatment of enterocutaneous fistulae

Enterocutaneous fistulae (ECFs) are abnormal sinus tract communications between the alimentary system and skin surface that can cause significant management problems and cost to the health care system. Interventional radiology can play an important role in diagnosis and treatment when conventional measures fail and additional surgery is difficult or poses a high risk. The management of patients with fistulae requires operator ingenuity and dedication, a multidisciplinary team approach, and an understanding of the pathophysiology. This article reviews the major issues in ECF management and the role of interventional radiology.

Abdominal and pelvic CT: is positive enteric contrast still necessary? Results of a retrospective observational study

PURPOSE

Evaluation of diagnostic accuracy of abdominal CT depending on the type of enteric contrast agent.

METHODS AND MATERIALS

Multislice CTs of 2,008 patients with different types of oral preparation (positive with barium, n = 576; neutral with water, n = 716; and no enteric contrast, n = 716) were retrospectively evaluated by two radiologists including delineation of intestinal segments and influence on diagnosis and diagnostic reliability exerted by the enteric contrast, using a three-point scale. Furthermore, diagnostic reliability of the delineation of selected enteric pathologies was noted. CT data were assigned into groups: oncology, inflammation, vascular, pathology, trauma and gastrointestinal pathology.

RESULTS

Delineation of the bowel was clearly practicable across all segments irrespective of the type of enteric contrast, though a slight impairment was observed without enteric contrast. Although delineation of intestinal pathologies was mostly classified "clearly delimitable" more difficulties occurred without oral contrast (neutral/positive/no contrast, 0.8 %/3.8 %/6.5 %). Compared to examinations without enteric contrast, there was a significant improvement in diagnosis that was even increased regarding the reader's diagnostic reliability. Positive opacification impaired detection of mucosal enhancement or intestinal bleeding.

CONCLUSION

Water can replace positive enteric contrast agents in abdominal CTs. However, selected clinical questions require individual enteric contrast preparations. Pathology detection is noticeably impaired without any enteric contrast.

Radiological diagnosis of rectocutaneous fistulas in a cat - a case report

Abscess and perirectal fistulas are common in humans but not so in animals. Fistulas located in tissues surrounding the anus are usually described in the course of furunculosis in dogs. This study presents the case of a one-year-old cat in which two rectocutaneous fistulas had formed. This process was a result of the chronic inflammation of tissues around the base of the tail due to the drainage of an abscess. The animal was referred for radiological examination with clinical signs of dyschezia. Faecal material was discharged only through the fistulas situated on both sides of the tail. The aim of the radiological examination was to preoperatively determine the course of the fistula tract and to identify their internal openings. Fistulography revealed that both fistulas were connected with each other and with the rectal lumen. Their external opening was located at the height of the 4th caudal vertebra, 1.5 cm (fistula on the right) and 2 cm (fistula on the left) from the wall of the rectum. The fistula located on the right side branched cranially. The rectal lumen in this area was significantly narrowed. Abscess formation resulting in the development of rectocutaneous fistulas has not yet been described in dogs or cats. In the present case, fistulography made it possible to identify directly the source and course of the fistula canal. This examination should be complemented by other diagnostic modalities, such as a contrast examination of the gastrointerstinal tract, ultrasound evaluation, and magnetic resonance imaging.

A Rare Spontaneous Gastrobiliary Fistula

We report the case of a 69-year-old man with a spontaneous gastrobiliary fistula. Internal biliary fistulas are usually the result of longstanding, untreated choledocholithiasis, cholecystolithiasis, peptic ulcers or rarely neoplasia. This patient’s unspecific clinical picture led to a late diagnosis, which was made during surgery.

How to cite this article: Chwiesko A, Jurkowska G, Kedra B, Okulczyk B, Kamocki Z, Dabrowski A. A Rare Spontaneous Gastrobiliary Fistula. Euroasian J Hepato-Gastroenterol 2014;4(2):101-103.

Tumor-bowel fistula: what radiologists should know

Tumor-bowel fistula is an under reported complication of abdomino-pelvic malignancies which may occur spontaneously due to tumor growth or can be associated with cancer treatment. Chemotherapy and radiotherapy are commonly responsible for tumor-bowel fistulas. Molecular targeted therapies are a new class of drugs that can cause tumor fistulization due to their antiangiogenic properties. Clinically, the fistula can be asymptomatic or can result in devastating complications. Imaging helps in the prompt detection of these fistulas and the complications associated with them. Management of tumor-bowel fistula is individualized but often involves discontinuation of the associated treatment. Radiologists should promptly alert the oncology team about the presence of tumor-bowel fistula and any risk factors for its occurrence like pneumatosis or large metastatic deposits close to bowel loops.

A case of colonic pseudoobstruction related to bacterial overgrowth due to a sigmoidocecal fistula

Colocolic fistulas are usually a complication of an inflammatory or neoplastic process. Development of these abnormal bowel communications may lead to bacterial overgrowth. We report on a 71-year-old man with a one-year history of recurrent abdominal distension and irregular bowel habits. Abdominal X-rays and computed tomography showed multiple air-fluid levels and loops of distended bowel without evidence of mechanical obstruction or diverticulitis. Colonoscopy showed a fistulous tract between the sigmoid colon and cecum. Results of a lactulose breath test showed high fasting breath CH4 levels, which were thought to be the result of intestinal bacterial overgrowth. The patient was diagnosed with a colonic pseudo-obstruction associated with bacterial overgrowth due to a sigmoidocecal fistula. We recommended surgical correction of the sigmoidocecal fistula; however, the patient requested medical treatment. After antibiotic therapy, the patient still had mild symptoms but no acute exacerbations.

Acquired esophagobronchial fistula without Ono's sign and with unusual cause

A 60-year-old woman presented with dyspnoea and respirophasic chest discomfort, as well as a history of idiopathic oesophageal diverticulum. Physical examinations showed no evidence of Ono's sign, fever and weight loss. Chest radiograph revealed a right-sided transudative pleural effusion. Barium oesophagogram made a diagnosis of acquired esophagobronchial fistula communicating between oesophagus and bronchus. The oesophagobronchial fistula, causing pleural effusions, was very small and could be caused by idiopathic oesophageal diverticulum. The pleural effusion was removed by thoracentesis, which improved her symptoms. Surgical therapy or covered oesophageal stenting was advised, but she declined. She is followed-up regularly on an outpatient basis.

Bouveret's syndrome: presentation of two cases with review of the literature and development of a surgical treatment strategy

BACKGROUND

Bouveret's syndrome causes gastric outlet obstruction when a gallstone is impacted in the duodenum or stomach via a bilioenteric fistula. It is a rare condition that causes significant morbidity and mortality and often occurs in the elderly with significant comorbidities. Individual diagnostic and treatment strategies are required for optimal management and outcome. The purpose of this paper is to develop a surgical strategy for optimized individual treatment of Bouveret's syndrome based on the available literature and motivated by our own experience.

CASE PRESENTATION

Two cases of Bouveret's syndrome are presented with individual management and restrictive surgical approaches tailored to the condition of the patients and intraoperative findings.

CONCLUSIONS

Improved diagnostics and restrictive individual surgical approaches have shown to lower the mortality rates of Bouveret's syndrome. For optimized outcome of the individual patient: The medical and perioperative management and time of surgery are tailored to the condition of the patient. CT-scan is most often required to secure the diagnosis. The surgical approach includes enterolithotomy alone or in combination with simultaneous or subsequent cholecystectomy and fistula repair. Lower overall morbidity and mortality are in favor of restrictive surgical approaches. The surgical strategy is adapted to the intraoperative findings and to the risk for secondary complications vs. the age and comorbidities of the patient.

Cancer survivorship, a unique and growing cohort in medical practice: radiology perspective

The unique medical and psychologic burdens of cancer survivorship have only recently been recognized. This rapidly expanding cohort of patients will be seen increasingly by non-oncology physicians who must consider medical issues related to their cancer or its therapy for any presenting symptoms. Appropriate use of clinical imaging is essential for diagnosing treatment-related complications, recurrent tumor, or emergence of second primaries. This article will review clinical imaging in common medical problems uniquely found in cancer survivors.

Benign oesophageal diseases: a review of the CT findings

A variety of benign conditions can affect the oesophagus, both primarily and secondarily. Traditionally fluoroscopic oesophagography and endoscopy have formed the mainstay for investigating oesophageal diseases. Increasing use of cross-sectional imaging means that many such diseases and their thoracic complications are now detected at computed tomography (CT), which is very often the first imaging tool. This review describes the CT manifestations of a range of benign oesophageal conditions and discusses the role of CT in their evaluation.

Radiation-induced distal ileal obstruction complicating ileostomy closure

BACKGROUND

Radiation enteropathy is a recognized complication in patients who undergo neoadjuvant radiotherapy for locally advanced rectal cancer. Routine formation of defunctioning loop ileostomy in these patients may mask the development of stricturing, terminal ileal and radiation enteropathy which later may complicate the ileostomy closure. Our aim was to assess the preventive techniques and key warning signs.

METHODS

We present two cases of ileostomy closure in patients with occult, radiation-induced, terminal ileal stricture and review the relevant literature.

RESULTS

The first case was complicated by dehiscence of the ileal anastomosis due to undiagnosed, downstream stenosis of the irradiated terminal ileum. A similar terminal ileal stricture was diagnosed in the second case by contrast fluoroscopy enabling an elective ileocolic anastomosis. The literature indicates the importance of identifying such problems prior to loop ileostomy closure.

CONCLUSIONS

Contrast studies before loop ileostomy closure are valuable in limiting the complications of radiation-induced distal ileal obstruction in selected patients.

Finding nemo: imaging findings, pitfalls, and complications of ingested fish bones in the alimentary canal

In Asian cuisine, fish is often prepared whole with the bones. Accidental fish bone (FB) ingestion is not an infrequently encountered condition in the emergency department. An impacted FB in the alimentary canal can lead to potentially life-threatening complications. For impacted FBs that cannot be visualized clinically, radiographs and multidetector computed tomography are helpful in localizing the FB, evaluating for complications, and planning treatment. In this pictorial essay, we illustrate the spectrum of radiological findings of impacted FBs, common imaging pitfalls, and complications. Finally, we highlight the imaging findings that are important to the clinician in planning treatment.

Complicated cholelithiasis: an unusual combination of acute pancreatitis and bouveret syndrome

Bouveret syndrome is a rare form of gallstone ileus. The purpose of the present study was to present the unusual case of a female patient with complicated cholelithiasis manifested as a combination of acute pancreatitis and concomitant Bouveret syndrome. A 61-year-old female patient was admitted to the emergency department complaining of mid-epigastric and right upper quadrant abdominal pain radiating band-like in the thoracic region of the back as well as repeated episodes of vomiting over the last 24 h. The initial correct diagnosis of pancreatitis was subsequently combined with the diagnosis of Bouveret syndrome as a computed tomography scan revealed the presence of a gallstone within the duodenum causing luminal obstruction. After failure of endoscopic gallstone removal, a surgical approach was undertaken where gallstone removal was followed by cholecystectomy and restoration of the anatomy by eliminating the fistula. The concomitant pancreatitis complicated the postoperative period and prolonged the length of hospital stay. However, the patient was discharge on the 45th postoperative day. Attempts for endoscopic removal of the impacted stone should be the initial therapeutic step. Surgery should be reserved for cases refractory to endoscopic intervention and when definite treatment is the actual challenge.

MRI and pelvic abscesses: a pictorial review

OBJECTIVE

The purpose of our article was to review the magnetic resonance imaging (MRI) features of pelvic abscesses. Pelvic abscesses account for a wide range of abnormalities from various etiologies.

CONCLUSION

MRI is being increasingly used for pelvic exploration. Radiologists must thus be aware of their features and characteristics.

CT antegrade colonography to assess proctectomy and temporary diverting ileostomy complications before early ileostomy takedown in patients with low rectal endometriosis

OBJECTIVE

The purpose of this study is to describe an imaging method based on a CT technique, CT antegrade colonography, for the evaluation of low anastomosis and to evaluate the value of CT antegrade colonography before early ileostomy closure after proctectomy in low rectal endometriosis.

MATERIALS AND METHODS

One hundred ninety-five patients referred for low rectal endometriosis underwent proctectomy and were eligible for early ileostomy closure. All patients underwent standard antegrade fluoroscopy (n=77) or CT antegrade colonography (n=118) 8 days after surgery. The negative predictive values, positive predictive values, sensitivity, specificity, and likelihood ratio of standard antegrade fluoroscopy and CT antegrade colonography in detecting anastomotic leakage and abscesses were assessed. The reference standard for positive and negative examinations was based on clinical follow-up, imaging, surgical, or interventional procedure findings.

RESULTS

Negative and positive predictive values for detecting anastomotic leakage were 100% (95% CI, 96.8-100%) and 100% (95% CI, 39.8-100%), respectively, for CT antegrade colonography and 98.6% (95% CI, 92.4-100%) and 100% (95% CI, 54.1-100%), respectively, for standard antegrade fluoroscopy. The negative and positive predictive values for detecting abscess were 100% (95% CI, 96.8-100%) and 100% (95% CI, 47.8-100%), respectively, for CT antegrade colonography and 97.3% (95% CI, 90.8-99.7%) and 100% (95% CI, 2.5-100%), respectively, for standard antegrade fluoroscopy.

CONCLUSION

CT antegrade colonography may play a major role in the evaluation of low anastomosis protected by an ileostomy after proctectomy in low rectal endometriosis, leading to the development of a new strategy with early restoration of the intestinal continuity.

Radiographic and endoscopic diagnosis and treatment of enterocutaneous fistulas

The management of enterocutaneous fistulas continues to be a challenging postoperative complication. Understanding the anatomy of the fistula optimizes its evaluation and management. Diagnostic radiology has always played an important role in this task. The use of plain radiography with contrasted studies and fistulograms is well documented in the earliest investigations of fistulas and they continue to be helpful techniques. The imaging techniques have evolved rapidly over the past 15 years with the introduction of cross-sectional imaging, ultrasound and endoscopy. The purpose of this chapter is to review both the diagnostic and therapeutic roles of fistulograms, small bowel follow-through, computed tomography, magnetic resonance imaging, ultrasound, and endoscopy in the setting of acquired enterocutaneous fistulas.

Uncommon acquired fistulae involving the digestive system: summary of data

PURPOSE

Most gastrointestinal fistulae commonly occur following surgery. A minority is caused by a myriad of other etiologies and is termed by some as "uncommon fistulae". The aim of this study was to review these fistulae and their treatment.

METHODS

A literature review was carried out. Searches were conducted in Pubmed and related references reviewed.

RESULTS

Except for Crohn's disease and diverticulitis, "uncommon fistulae" are described in case reports or very small case series. Most of the patients were treated by surgery.

CONCLUSIONS

The anatomic features of the fistula and the etiology usually dictate the approach. Most patients will eventually need surgery to resolve this pathology.

Enterolith with enterocolic fistula: the diagnostic approach

An enterolith is a mixed concretion formed in GIT, usually rare in humans. Primary enteroliths are formed in small bowel, typically within a diverticulum and secondary enteroliths in gallbladder. This case report highlights the presence of an enterocolic fistula; probably a postradiotherapy complication; and an enterolith without associated small bowel or colonic diverticuli. We have discussed the various diagnostic modalities used to reach a preoperative diagnosis of this rare condition. Imaging plays an important role in the detection and management of acquired gastrointestinal fistulas. The more routine use of cross-sectional imaging (especially computed tomography and magnetic resonance imaging) has altered the standard sequence of radiologic evaluation for possible fistulas, but fluoroscopic studies remain a valuable complement, especially for confirming and defining the anomalous communications.

Evolution of imaging for abdominal perforation

INTRODUCTION

Gastrointestinal (GI) perforation is a common surgical presentation. In recent years, computed tomography (CT) has been shown to be accurate for predicting the site of GI perforation, and has become the investigation of choice. However the signs may be subtle or only indirectly related to the site or aetiology of perforation.

SUBJECTS AND METHODS

A MEDLINE and PubMed search was performed for journals before June 2009 with MeSH major terms 'CT' and 'perforation'. Non-English speaking literature was excluded.

RESULTS

Examples of GI perforation of various aetiologies are reviewed (inflammatory, neoplastic, traumatic and iatrogenic) high-lighting characteristic CT appearances as well as pitfalls in diagnosis. Features of perforation include the presence of free gas or fluid within the supra- and/or inframesocolic compartments, segmental bowel wall thickening, bowel wall discontinuity, stranding of the mesenteric fat and abscess formation.

CONCLUSIONS

These differentiating features facilitate accurate multidisciplinary pre-operative evaluation, necessary to plan patient management and potential surgical approach.

Colopleural fistula: case report and review of the literature

We report a 28-year-old woman, pregnant, at 24 weeks, with 3-day history of right-sided chest pain and shortness of breath. Few hours after admission, she delivered a dead baby. She had a history of right partial hepatic lobotomy and cholecystectomy at UK on May 2004 because of multiple pyogenic liver abscesses. Chest examination revealed signs of hydrothorax on the right side. Chest X-ray showed pleural effusion on the right side. Pleural fluid was exudative with high neutrophils. Gram stain and culture showed multiple organisms. CT scan chest and abdomen with contrast, combined with barium enema, revealed right colothorax communication. Colothorax fistula was closed surgically. On the following days, the patient's symptoms resolved, and she was consequently discharged.

Tracheo-oesophageal fistula diagnosed with multidetector computed tomography

This case highlights important issues in investigation of patients with suspected tracheo-oesophageal fistula including the value of multidetector computed tomography, the importance of thorough imaging evaluation when high clinical suspicion of tracheo-oesophageal fistula exists and the value of close interaction between radiologists and intensive care physicians in the investigation of these patients.

CT features of esophageal emergencies

Esophageal emergencies-primarily, perforation and conditions with the potential to progress to perforation-result in significant morbidity and mortality if they are not recognized and treated promptly. The spectrum of esophageal emergencies includes esophagitis, foreign body impaction, and traumatic esophageal injury. Because there is considerable variability in the clinical manifestations of emergent esophageal conditions, computed tomography (CT) may play both primary and complementary roles in their diagnosis and evaluation. An awareness of the CT findings associated with the spectrum of acute esophageal disease facilitates the accurate and prompt diagnosis of esophageal emergencies and thereby contributes to a more successful outcome.

Fatal hemorrhage from a gastroaortic fistula secondary to gastric ulceration associated with Nissen fundoplication and nonsteroidal anti-inflammatory drug use

Acute gastrointestinal hemorrhage from a gastroaortic fistula in the gastric fundoplication pouch is a rare complication of Nissen fundoplication. The present case reports a gastroaortic fistula secondary to gastric ulceration associated with prior Nissen fundoplication and nonsteroidal anti-inflammatory drug use. A 55-year-old man presented with massive hematemesis and died of exsanguination during emergency laparotomy. Recognition of factors that predispose a patient to gastric ulceration after fundoplication, including nonsteroidal anti-inflammatory drug use, is critical to arouse the high index of suspicion required to diagnose and manage this life-threatening complication.

Case 117: Actinomycosis of Left Kidney with Sinus Tracts

A 39-year-old Samoan man presented to the emergency department with fever, progressive weakness, and left flank pain of 1-month duration. For several months, he had also experienced progressive weight loss. There was no history of recent trauma, and he was not taking any medication. His medical history was notable for a large left groin abscess and left lower lobe pneumonia of unknown cause 1 year prior to the current admission. Furthermore, he had undergone exploratory laparotomy and gastric surgery for peptic ulcer disease approximately 10 years ago. Physical examination findings were positive for a tender firm mass in the left flank with no associated skin changes. Laboratory findings revealed an elevated white blood cell count of 18 x 10(9)/L. The urine cultures were negative. A computed tomographic (CT) image obtained 1 year prior to the current admission was unremarkable. CT of the abdomen and pelvis (section thickness, 5 mm) was performed after ingestion of 900 mL of 2% diatrizoate meglumine and diatrizoate sodium (Gastrografin; Bracco Diagnostics, Princeton, NJ). A 150-mL dose of iohexol (300 mg of iodine per milliliter) (Omnipaque; Nycomed, New York, NY) was administered intravenously at a rate of 4 mL/sec with a 70-second scan delay. Unenhanced CT images (not shown) did not reveal any areas of high attenuation.

Diagnostic performance of MRI for detection of intestinal fistulas in patients with complicated inflammatory bowel conditions

The diagnostic performance of magnetic resonance imaging (MRI) for detection of intestinal fistulas, other than perianal, in patients with known complicated inflammatory bowel conditions (CIBC) was investigated. Our study group consisted of 20 patients (12 women, mean age 43 years) with CIBC, including Crohn's disease (n=13), colonic diverticulitis (n=3), colitis after radiotherapy (n=3) and of postoperative origin (n=1). Eleven surgically proven enteral fistulas were known in ten (50%) of these patients, being of enterovesical (n=3), enterocolic (n=2), enteroenteral (n=2), rectovaginal (n=2), rectovaginovesical (n=1) and of entercutaneous (n=1) localisation. The other ten patients (50%), used as the control group, showed MR features of CIBC, although without any fistulous tract. Multiplanar T1- and T2-weighted sequences had been performed, including gadolinium-enhanced acquisition with fat saturation (1.5 T). MR findings were independently blindly and retrospectively reviewed by three radiologists for the presence and etiology of any fistula, as well as visualization and characterization of the fistulous tract. Results were compared with surgical findings (n=16) and clinical evolution (n=4). Interobserver agreement was calculated. Interobserver agreement kappa for fistula detection was 0.71. Overall sensitivity, specificity and accuracy for fistula detection were 78.6%, 75% and 77.2%, respectively. Sensitivity for fistula characterization was 80.6%, with visualization of the fistulous tract in all cases, whereby T1-weighted gadolinium-enhanced fat-saturated images were considered the most useful sequences. Gadolinium-enhanced MRI is a reliable and reproducible tool for detection of enteral fistulas secondary to inflammatory conditions.

Anatomic and pathologic findings at external phased-array pelvic MR imaging after surgery for anorectal disease

Pelvic magnetic resonance (MR) imaging is useful for identification of postoperative changes, complications, and disease recurrence in patients who have undergone surgery for primary or recurrent anorectal disease. Commonly used interventions include treatment for anorectal carcinoma: anterior rectal resection with or without creation of different colic anastomoses and abdominoperineal excision with or without pelvic reconstruction (omentoplasty, placement of myocutaneous flaps). Other common interventions include treatment for inflammatory bowel disease (coloproctectomy with or without creation of an ileoanal anastomosis and ileal pouch) and treatment for fistulas (placement of flaps or setons). Postoperative anatomic changes and formation of scar tissue can usually be identified with consecutive MR imaging examinations. Pelvic MR imaging is an accurate technique for assessment of complications including anastomotic leakage, septic complications such as fistulas and abscesses, neoplastic recurrence, and other less common complications (perineal hernia, peritoneal pseudocyst). The sophisticated surgical procedures used in rectal surgery can alter normal anatomy and make image interpretation difficult. Thus, familiarity with the appearances of postoperative anatomic changes, complications, and tumor recurrence is essential for accurate MR imaging evaluation after surgery for anorectal disease.

Aorto-enteric fistula: CT findings

The objective of this pictorial essay is to present the different CT findings encountered in patients with aorto-enteric fistulas (AEFs). An AEF is a rare and sometimes disastrous occurrence, responsible for intermittent or massive gastrointestinal hemorrhage and hematemesis. CT provides fast and effective evaluation in hemodynamically stable patients suspected of having an AEF.

Review article: intestinal failure

Intestinal failure is a specific disease entity resulting from intestinal resection or disease-associated malabsorption and characterized by the inability to maintain protein-energy, fluid, electrolyte or micronutrient balance. We performed a MEDLINE search (1966-2006) to identify relevant articles, using keywords intestinal failure, parenteral or enteral nutrition, intestinal fistula and short bowel syndrome. Causes of intestinal failure are varied, with self-limiting or 'Type 1' intestinal failure occurring relatively commonly following abdominal surgery, necessitating short-term fluid or nutritional support. The rarer, 'Type 2' intestinal failure, is associated with septic, metabolic and complex nutritional complications, usually following surgical resection in patients with Crohn's or mesenteric vascular disease. A multidisciplinary approach to the management of patients with Type 2 intestinal failure is crucial: resolution of sepsis is required before adequate nutritional repletion can be achieved, and it is important to optimize nutritional status, not only through enteral or parenteral supplementation, but also by addressing complications of short bowel syndrome, before considering definitive surgical reconstruction. A structured approach to the management of Type 2 intestinal failure should reduce the likelihood of these complex patients developing 'Type 3' intestinal failure, which is characterized by the need for long-term parenteral nutrition.

Multidetector Computed Tomography Imaging of Aortoenteric Fistula

Three case reports illustrating multidetector computed tomography (CT) imaging findings of secondary aortoenteric fistula (AEF) are described and presented in axial sections, multiplanar reformats, and 3-dimensional reconstruction. Fistulae occurred in the early and late postgrafting period and involved both end-to-end and end-to-side aortic graft anastomoses. Multidetector CT is quick and accurate in the diagnosis of bleeding AEF.

Radiologic diagnosis of gastrointestinal perforation

Perforations of the gastrointestinal tract have many causes. Holes in the wall of gastrointestinal organs can be created by blunt or penetrating trauma, iatrogenic injury, inflammatory conditions that penetrate the serosa or adventitia, extrinsic neoplasms that invade the gastrointestinal tract, or primary neoplasms that penetrate outside the wall of gastrointestinal organs. This article provides a radiologic approach for investigating the wide variety of gastrointestinal perforations. General principles about contrast agents and studies are reviewed, and then perforations in specific gastrointestinal organs are discussed.