Endoluminal ultrasound biomicroscopy as a reliable tool for in vivo assessment of colonic inflammation in rats.
OBJECTIVE
Endoscopic ultrasound (EUS) imaging of the colon is an important diagnostic tool for early neoplasia, although usually restricted to the rectum in inflammatory bowel disease (IBD). This study aimed to evaluate the ability of an endoluminal ultrasound biomicroscopic (eUBM) system to detect and characterize lesions simulating Crohn's disease in the colon of rats in vivo.


METHODS
Colitis was induced with trinitrobenzene sulfonic acid instillated in the distal colon. Eighteen Wistar rats were submitted to eUBM in three time points: week 1 group (18 animals examined on day 3 after colitis induction), week 2 group (12 animals on days 3 and 10), and week 3 group (7 animals on days 3, 10, and 17). This design yielded distinct inflammation intensities. Three untreated rats were used for acquisition of control images. Scores were used for comparison with histology.


RESULTS
Scores for eUBM and histology in the different moments of examination achieved a Spearman's rank correlation coefficient of 0.87 (p < 0.001). Findings of wall thickening presented positive predictive value (PPV) and sensitivity of 94 and of 100 %, respectively. Superficial and deep ulcers presented a PPV of 89 and 80 %, respectively, and negative predictive values of 100 and 85 %, respectively.


CONCLUSIONS
Accurate detection and analysis of the lesions was achieved. The model is essential for the clinical development of the technique and a reproducible method for the evaluation of experimental colitis. eUBM might be applicable in different segments of the gut, developing into a novel adjunct method for IBD evaluation.
Post-Graduation Program in Surgical Sciences, Department of Surgery, School of Medicine, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
Marcelo Alexandre Pinto
MA
de Britto
Rossana Colla
RC
Soletti
Alberto
A
Schanaider
Kalil
K
Madi
Heitor Siffert Pereira
HS
de Souza
João Carlos
JC
Machado
D000818:Animals; D003092:Colitis / Q000000981:diagnostic imaging* / Q000473:pathology; D003113:Colonoscopy; D003657:Decision Making; D019160:Endosonography / Q000379:methods*; D007249:Inflammation / Q000000981:diagnostic imaging* / Q000473:pathology; D008297:Male; D033401:Microscopy, Acoustic / Q000379:methods*; D011237:Predictive Value of Tests; D051381:Rats; D017208:Rats, Wistar