1. Omental Infarction and Epiploic Appendagitis
Scott Nguyen MD
Oct 10, 2006

2. Epiploic Appendagitis
Small adipose protrusions from serosal surface of colon
located along taenia throughout colon
Most located at sigmoid or rectum, cecum
Supplied by small artery and vein through the narrow pedicle
Mobility of the fat-laden heavy appendix makes it prone to torsion, kinking, or stretching resulting in venous thrombosis

3. Omental Infarction
Segment of Omentum succeptible to infarction as a result of torsion or venous thrombosis
Primary and Secondary
Predilection for Right Abdomen
Primary and Secondary
Secondary – associated w/ another intraabdominal process (omental cyst, hernia, tumor, adhesion, post surgery)
Predilection for Right Abdomen
d/t abnormality in embryonic formation of the Right side of the omentum and Right epliploic vessels
Right omentum longer and more mobile

5. Risk Factors for Torsion or Infarction
OBESITY
Fat accumulation in appendices – pedunculated nature and mobility increase chances of torsion
Fat deposition may outgrow the bloody supply predisposing to ischemia
Heavy exercise and excessive stretching – excess movement of omentum

6. EA – prevalence in LLQ often misdiag as diverticulits
OT – R abdomen…cholecystitis or appy
European Radiology

7. Epiploic Appendigits J Clinical Ultrasound 2002 30:481-95
Only few series in literature…..few cases over many years
Concentrated in LLQ
Since diverticulitis was often working diagnosis, CT was method of choice in diagnosing these
Often initially thought to be diverticulitis
CT confirmed that was EA
J Clinical Ultrasound :481-95

8. Epiploic Appendagitis often misdiagnosed as Diverticulitis
Retrospective Korean study comparing 8 EA to 18 Diverticulitis
Often confused for Diverticulitis
EA – no assoc GI sx, few w/ fever and leukocytosis
IF do BE then will see no diverticulitis and see mass effect from appendix inflammation

9. Omental Infarction
More often found at exploration for possible appendicitis
Higher likelihood of resection
Several reports in children, especially obese

10. Normal Epiploic Appendices

11. US normal epiploic appendices

12. CT Epiploic Appendagitis
Typical CT findings -- central hypodensity is fat of appendix, w/ surrounding inflamm rim
Adjacent colon is normal
Inflamm can adhere to anterior abd wall

14. Tendency to Abut abdominal wall

15. Sometimes can see central hyperdensity w/in append -- area of necrosis or hemorrhage, or thrombosis
2nd image w/ normal contrast filled diverticula

16. Sonogram
Sonographic findings – hyperechoic ovoid lesion, Hypoechoic rim. Hypoechoic center – necrosis.
US easy cause these usu right underneath abd wall

17. Treatment Epiploic Appendagits
Conservative
No surgery necessary
Symptoms treated with analgesics
No antibiotics necessary
Most literature support Imaging saves patient from exploratory laparotomy
Repeat imaging often shows complete resolution of inflammation
Occasionally fibrous band or calcified appendage may remain

18. CT at 6 weeks to see almost resolution of inflammation

19. Epiploic Appendagitis
Rarely complications of nonoperative management
4 cases of abscess formation
1 case intestinal obstruction from adhesions

20. Omental Infarct
Usually ill defined heterogenous fat density if in early stage ( < 15 days)
Cake like density

22. Sometimes can see whorling of omentum……consistent w/ omental torsion

23. Evolves to a smaller, well defined lesion w/ a continous hyperdense rim > 30 days

24. Evolutionary changes in omental infarcts
Evolutionary changes in omental infarcts. Unlike epiploic appendagitis, which resolves completely upon repeat imaging. F/u imaging usually results in smaller fat lesion w/ hyperdense rim

25. Evolutionary changes

26. Micrographs reveal a intense inflammatory infiltrate into the fat

27. Treatment of Omental Infarction
Observation
NSAIDS
No need for antibiotics
Rarely abscess

28. Largest Series in Literature 40 patients, 1988-1997
20 epiploic appendagitis
11 Omental infarction
9 Unspecified abdominal focal fat infarction
All had CT or US
No patients had to undergo exploration
No antibiotics
Most had symptoms resolve w/in 7 days

29. Appendices Epiploicae
“They rarely excite much notice, except to be cursed as an impediment to precise anastomosis of the colon or gratefully acknowledged as an added measure of protection when used to reinforce a precarious suture line.”