GASTROENTEROLOGY ARTICLE OF THE WEEK
November 14, 2002
Schwartz DA, et al. EUS for rectal disease. Gastrointest Endosc 2002;56:100-109.
1. EUS in the evaluation of fecal incontinence
a. Is as sensitive as EMG in detecting sphincter injuries
b. Defects of the IAS appear as hyperechoic breaks in the normally hypoechoic
sphincter
c. Defects of the EAS appear as hypoechoic areas in the normally hyperechoic
sphincter.
d. False positive results of EAS defects is more common in men.
2. EUS in the evaluation of rectal carcinoma
a. Accuracy of determining depth of invasion ranges from 80% to 95%, which is
higher than CT and MRI.
b. EUS tends to understage depth of invasion
c. 17% of lesions cannot be staged due to stenosis
d. pre-operative radiation enhances EUS staging accuracy.
True or False
3. Endoscopic ultrasound is useful to stage local invasion by rectal carcinoma, but does not help in detecting lymphatic spread.
4. EUS staging including FNA of suspicious nodes improves outcome in rectal cancer.
5. Studies suggest that rectal EUS is more accurate in detecting rectal fistulas than CT, MRI or exam under anesthesia.
6. CT scan is superior to rectal EUS to detect recurrence of rectal cancer.
7. In rectal cancer staging, EUS is definitely superior to CT and MRI in lymph node staging.
8. Due to post-surgical changes, rectal EUS has a low specificity in detecting recurrent malignancy, FNA in questionable cases may improve specificity.