Epiploic appendagitis (epiploic appendicitis) - an uncommon etiology of acute abdomen

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1 Epiploic appendagitis (epiploic appendicitis) - an uncommon etiology of acute abdomen Poster No.: C-0801 Congress: ECR 2012 Type: Educational Exhibit Authors: A. Coroliuc, M. Prosie, E. Ganeva, I. Pascu, P. Cart ; Charleville Mézières/FR, Charleville Mézières /FR Keywords: Emergency, Abdomen, CT, Diagnostic procedure, Acute DOI: /ecr2012/C-0801 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. Page 1 of 21

2 Learning objectives Epiploic appendagitis is a rare and not so well known cause of acute non-surgical abdomen. At the emergency department, these patients complain about abdominal pain, sometimes accompanied by nausea or vomiting, but without transit disorders or biological inflammatory syndrome (without hyperleukocytosis). The patient also may have a lowgrade fever. The clinical signs mimic an acute surgical abdomen: eg. appendicitis or diverticulitis of the ascending colon if the pain is located on the right side, and the diverticulitis of descending or sigmoid colon if the pain occurs on the left side. The purpose of this poster is to present the radiological signs, especially CT scan signs (characteristic signs) that appear in epiploic appendagitis in order to avoid inadequate treatment (and therefore, its costs). The antibiotic therapy, hospitalization or surgical explorations are not necessary for a self-limited inflammatory pathology. In this case only symptomatic treatments are necessary (anti-inflammatory and analgesic therapy). Page 2 of 21

3 Background Epiploic appendices, also known as epiploicae appendices, are small, ovoid, fat-filled sacs or finger-like projection, covered by the peritoneum, with a variable length, between 0.5 and 5 cm (mean 3 cm), and 1 to 2 cm thick (Fig.1). They are arranged in two separate longitudinal rows next to the anterior and posterior tenia coli over the external aspect of the colon and hang into the peritoneal cavity. Although the total number of epiploic appendages on the colon is about 100, the size and number increase in the lower abdominal quadrants (57% are located on the sigmoid colon and 26% on the ileocecum). Vascularisation of an appendage is provided by one or two small end arteries branching from the vasa recta longa of the colon and is drained by a tortuous vein passing through its narrow pedicle (Fig.2). Physiological role is not clearly defined. The epiploic appendages are presumed to serve a defensive mechanism similar with the one offered by the greater omentum. They may also act as a protective cushion during peristalsis. Primary epiploic appendagitis is an ischemic infarction of an epiploic fringe caused by its torsion or spontaneous venous thrombosis of a draining appendageal vein, when the appendix is abnormally long and wide and is distinguished from secondary appendagitis, which can occur in patients with pericolic inflammatory fluid, as in colitis. Other proposed causes for secondary appendagitis are lymphoid hyperplasia or bacterial invasion secondary to a deep abdominal infection (diverticulitis, appendicitis, pancreatitis or cholecystitis) making the coexistence of these pathologies possible. Treatment of epiploic appendagitis is based on treatment for primary abnormality. This pathology affects both sexes equally and can occur ages 12 through 82 (extremes described in the literature), predominantly ages 20 through 50. Primary epiploic appendagitis occurs more frequently in obese patients and in women. Rarely, epiploic appendages may be involved in other pathologies: eg. hernia, it can calcify and detach appearing as free foreign bodies in the peritoneum or it can give omental adhesions. There are no known risk factors but some studies claim that obesity is a contributing factor. Well tolerated by patients, AE is usually manifested by localized, cramps-like, non irradiated pain. Low grade fever may occur. This epiploic fringes torsion is most commonly located at cecum and left colon. This location explains diagnostic errors that can lead to surgical exploration in subjects who did not have imaging examinations. AE are located 55% in right lower abdominal quadrant, 30% in left lower quadrant and 10% in hypogastric region. Nausea and vomiting occur in only one quarter of cases. On clinical examination palpation can identify an abdominal mass with tenderness in 10-30% of cases. Page 3 of 21

4 Biological exploration can detect only a light hyperleukocytosis and a discrete inflammatory syndrome (increased CRP). Symptoms persist between 4 to 7 days. Medical treatment is started only after a definite diagnosis through imaging evaluation. Currently, these patients do not require hospitalization, as usually as this pathology frequently occurs in young patients without a major medical history, ambulatory treatment is sufficient. Conservatory treatment with oral anti-inflammatory medication and analgesics for 6 days is sufficient to control the pain and inflammation, antibiotics is not necessary. Rarely, complications can occur such as a mechanical occlusion, abscess, intussusceptions, adhesion, intraperitoneal loose bodies, peritonitis. Page 4 of 21

5 Images for this section: Fig. 1: Epiploic appendices correspond to peritoneum covered fatty structures about 2 to 5 cm long /EURORAD/CASE.7630 Page 5 of 21

6 Fig. 2: A cross-sectional diagram of the colon, showing the relationship between epiploic appendices (A), colic artery (B), straight artery (C), mesocolon (D) /EURORAD/CASE.1113 Page 6 of 21

7 Imaging findings OR Procedure details Our population Our study takes into account on a population of five patients (3 men and 2 women, age range years) presented at the emergency department, three with left flank pain and two with right flank pain. All of them have passed an enhanced CT scan and one of them has passed also an abdominal ultrasound exam. Two patients had a discreet inflammatory syndrome (CRP increased at 57, respective 97), and the others had a normally laboratory results. Only one patient presented a low grade fever, when the rest of them were afebrile. Imaging findings Normally, these epiploic appendices are not visible to ultrasound or CT, unless ascites is present. In this case, these appendages look like fatty density extensions (fig.3). At contrast-enhanced CT scan, the pathognomonic sign is typically 1-4 cm ovoid formation with fat density with surrounding hyperdense rim ("hyperattenuating ring sign") representing inflamed peritoneal serous adjacent to the colon and periappendageal fat stranding (fig.4). Primary epiploic appendagitis may have a lobular appearance because of two or more affected, contiguous epiploic appendages (fig.5). Sometimes there may be a central hyperdensity ("central dot sign", fig.6) corresponding to epiploic vessel thrombosis and hemorrhagic necrosis (Rioux and al.). The "dot sign" is useful for diagnosis, but its absence does not exclude the diagnosis of acute epiploic appendagitis. No abnormalities of the adjacent colon wall, is a necessary sign to evoke this diagnosis and differentiate it from a diverticulitis, appendicitis or a salpingitis. Also the differential diagnosis with omental infarction, mesenteric panniculitis and primary tumors or metastases of omentum has to be done. No ascites fluid is present. The regression of CT signs of inflammatory signs and parietal peritoneum thickening is observed after 1-3 months, sometimes with fibrous organization (Barbier and al.). Rarely, these lesions can calcify and lead to "peritoneal mice" described by surgeons. During ultrasound, there is a hyperechoic formation, nodular (or polilobular appearance), 3-5 cm in diameter, adjacent to the colic wall (hyperechoic character represent ischemic fat). This structure is surrounded by a hypoechoic border; it is non-compressible solid mass without Doppler flow. The absence of a Doppler signal due an ischemic anomaly as a result of torsion in epiploic appendagitis is a useful finding to differentiate epiploic appendagitis from acute diverticulitis. You may also notice an inflammatory thickening of the adjacent peritoneum without intra-peritoneal fluid. Changes to the colonic wall are not seen. Ultrasound diagnosis is difficult and nonspecific (fig.7-8). Page 7 of 21

8 MRI imaging is not a routine examination for abdominal pain at emergency department. It is useful for patients whom the risks of radiation or the potential nephrotoxicity of iodinated contrast agents is a major concern, such as pregnant and pediatric patients. The high soft tissue contrast of MR allows identification of the central adipose tissue portion of EA and the inflammatory changes in the surrounding fat planes, even without contrast medium administration. Unenhanced MR acquisition is a useful diagnostic tool in patients with impaired renal function. MR images for acute epiploic appendagitis show an oval fatty lesion, located adjacent to the sigmoid colon and associated with stranding of periappendicular fat and thickening of the parietal peritoneum. T1- and T2-weighted images show a focal lesion with high-signal intensity paralleling that of fat. STIR MR images show a high-signal-intensity rim and inflammation in the surrounding fat. Contrastenhanced T1-weighted images depict an enhancing rim surrounding the fatty lesion (fig.9-12). Page 8 of 21

9 Images for this section: Fig. 3: Epiploic appendices visible in ascites fluid at CT scan. RADIOLOGY, CH MANCHESTER - Charleville Mézières/FR Page 9 of 21

10 Fig. 4: Hyperattenuating ring sign represent inflamed peritoneal serous adjacent to the colon and periappendageal fat stranding RADIOLOGY, CH MANCHESTER - Charleville Mézières/FR Page 10 of 21

11 Fig. 5: A lobular appearance of epiploic appendagitis RADIOLOGY, CH MANCHESTER - Charleville Mézières/FR Page 11 of 21

12 Fig. 6: Central dot sign correspond to epiploic vessel thrombosis and hemorrhagic necrosis RADIOLOGY, CH MANCHESTER - Charleville Mézières/FR Page 12 of 21

13 Fig. 7: Hyperechoic nodular formation, adjacent to the colic wall, without Doppler flow RADIOLOGY, CH MANCHESTER - Charleville Mézières/FR Page 13 of 21

14 Fig. 8: Polilobular appearance of epiploic appendagitis RADIOLOGY, CH MANCHESTER - Charleville Mézières/FR Page 14 of 21

15 Fig. 9: Axial unenhanced T1- (fig.9) and T2-weighted (fig.10) images. Roundish lesion measuring 2,5 cm, abutting the distal descending colon, and consisting of a hyperintense fatty center with peripheral soft tissue rim. Page 15 of 21

16 Fig. 10: Axial unenhanced T1- (fig.9) and T2-weighted (fig.10) images. Roundish lesion measuring 2,5 cm, abutting the distal descending colon, and consisting of a hyperintense fatty center with peripheral soft tissue rim. Page 16 of 21

17 Fig. 11: Unenhanced fat suppressed (SPIR) T1-weighted image. Signal loss in the central portion of the pericolonic lesion, confirming its fatty content. Page 17 of 21

18 Fig. 12: Post-contrast fat suppressed (SPIR) T1-weighted image. Peripheral rim enhancement consistent with inflammation involving the pericolonic lesion and mild inflammatory stranding in the surrounding fat planes. Page 18 of 21

19 Conclusion Appendagitis is responsible for an acute abdominal findings and diagnostic difficulties. Nonspecific symptoms of this disease can easily lead to confusion with appendicitis, renal colic or diverticulitis. This localized pain requires implementation of imaging examinations such as ultrasound and CT scan, which will confirm the diagnosis. Knowledge of this entity and the clinical findings is necessary in the diagnostic approach of acute abdomen. Once diagnostic establish, treatment is simple and is done in ambulatory. Complications of this pathology are rare. Epiploic appendagitis is a rare but not exceptional pathology. Page 19 of 21

20 Personal Information Alina Coroliuc, MD PGY5 Radiology Resident Centre Hospitalier de Charleville-Mezieres 45, Avenue de Manchester - B.P Charleville-Mezieres Cedex, France coroliuc_alina@yahoo.com, acoroliuc@ch-charleville-mezieres.fr Page 20 of 21

21 References 1. Almeida, AT; Melao, L; Viamonte, B; Cunha, R; Pereira, JM. (2009). Epiploic Appendagitis: An Entity Frequently Unkown to Clinicians - Diagnostic Imaging, Pitfalls, and Look-Alikes. AJR, Bretagnol, F; Gomez, MA; Pautrat, K; Scotto, B; de Calan, L. (2003). Appendicite epiploique primitive: une etiologie d'abdomen aigu revelee par la tomodensitometrie. Annales de Chirurgie, Cakirer, S.; Demir,K.; Beser, M.; Galip, GM. (s.d.). EURORAD. Consulté le January 22, 2012, sur 4. Gelrud, A; Cardenas, A; Chopra, S. (n.d.). Up to Date. Retrieved 2012, from site Web UptoDate: 5. Leclercq, P; Dorthu, L. (2010). Epiploic Appendagitis. CMAJ, Oriot, Ph.; Dance, E; Thys, Fr. (2007). Université catholique de Louvain. Consulté le July 6, 2011, sur %202007/avril/91-94.pdf 7. Rao, PM; Novelline, RA; and all. (1999). Case 6: Primary Epiploic Appendagitis. Radiology, Sahin H, Sever A, Harman M, Elmas N. (s.d.). EURORAD. Consulté le January 22, 2012, sur 9. Singh, A; Danrad, R; Hahn, PF; Blake, MA; Mueller, PR; Novelline,RA. (2007). MR Imaging of the Acute Abdomen and Pelvis: Acute Appendicitis and Beyond. RadioGraphics, Singh, A; Gervais, D; Hahn, P; Sagar, P; Mueller, P; Novelline, R. (2005). Acute Epiploic Appendagitis and Its Mimics. RadioGraphics, Singh, AK; Gervais, DA; Hahn, PF; Rhea, J; Mueller, PR. (2004). CT Appearance of Acute Appendagitis. AJR, Tonolini, M.; Ravelli, A.; Bianco, R. (s.d.). EURORAD. Consulté le January 22, 2012, sur Page 21 of 21