25 / 78
DCMS online
. org
Northeast Florida Medicine
Vol. 66, No. 4 2015
25
Inflammatory Bowel Disease
duration of colonic involvement.
51
It is now believed that
the risk of developing CRC in UC and CD is identical.
52
Traditionally, interval colonoscopies with random
biopsies of normal mucosa and targeted biopsies of
suspicious lesions have been recommended for dysplasia
surveillance in patients with chronic colitis. Newer methods
aimed at detecting dysplastic mucosa have been studied.
High-definition white light endoscopy and enhanced
magnification colonoscopy have been used to increase
the yield in detecting dysplasia. Recent colitis surveillance
studies showed that high-definition colonoscopy improved
dysplasia detection compared to standard definition.
53
Chromoendoscopy is a dye-spraying technique that
highlights the borders and surface architecture of
neoplastic lesions (pit pattern). Chromoendoscopy helps
in unmasking and delineating subtle lesions and aids in the
differentiation of neoplastic and non-neoplastic tissue.
54
With this method, random biopsies of apparently normal
mucosa are of negligible additional value.
55,56
Diagnostic
yield of chromoendoscopy is comparable when methylene
blue or indigo carmine are used as the contrast agent.
57,58
Chromoendoscopy has been compared to standard-
definition endoscopy for detection of neoplasia in both
IBD and non-IBD patients and has been shown to be
superior.
59
Another meta-analysis looked at the diagnostic
accuracy of chromoendoscopy compared to histology and
reported a sensitivity of 83.3 percent and specificity 91.3
percent for chromoendoscopy in detection of intraepithelial
neoplasia.
60
Several randomized studies suggest that
advanced endoscopic imaging modalities may obviate the
need for multiple randombiopsies for dysplasia surveillance
in IBD patients with chronic colitis.
Virtual chromoendoscopy technologieshavebeendeveloped
as an alternative to dye based chromoendoscopy. Virtual
chromoendoscopy relies on the use of selective light filters
and post-image processing techniques to highlight vessel and
crypt architecture by altering the light that is emitted to the
mucosa. Commercially available virtual chromoendoscopy
techniques are narrowband imaging (NBI; Olympus, Tokyo,
Japan), i-scan (Pentax,Tokyo, Japan), Fuji IntelligentChromo
Endoscopy (FICE; Fujinon, Tokyo, Japan).
61
Confocal laser endomicroscopy is another advanced
imaging technique that makes histologic assessment possible
at the cellular and subcellular levels during endoscopy.
62
The potential application of confocal laser endomicroscopy
in IBD patients will be in combination with white-light
endoscopy or chromoendoscopy.
Advanced endoscopic imaging modalities including
high-definition endoscopy, chromoendoscopy, virtual
chromoendoscopy and confocal laser endomicroscopy have
the potential to significantly improve the detection of flat
and subtle dysplasia without the need for random biopsies.
In addition, these novel techniques aid in decision-making
and make it possible to resect a potentially dysplastic or
neoplastic lesion at the time of CRC screening, even before
having the results of biopsy.
63
Conclusion:
Endoscopy is fundamental to the care of patients with
inflammatory bowel disease (IBD) and is essential for
diagnosing and treating both Crohn’s disease (CD) and
ulcerative colitis (UC). Endoscopy is used to make an
initial diagnosis of IBD, distinguish CD from UC, assess
disease extent and activity, monitor response to therapy,
survey for dysplasia, and provide endoscopic treatment
strictures. The new advances in endoscopy resulted in a
major paradigm shift in how we diagnose and treat patients
with IBD. Endoscopy as a historic diagnostic tool has been
turned into an essential mean in surveillance and treatment
of patients with IBD.
v
References
1. Markowitz J, Kahn E, Grancher K, Hyams J, Treem W,
et al. Atypical rectosigmoid histology in children with
newly diagnosed ulcerative colitis.
Am J Gastroenterol.
1993 Dec;88(12):2034–7.
2. Robert ME, Skacel M, Ullman T, Bernstein CN, et al.
Patterns of colonic involvement at initial presentation in
ulcerative colitis: a retrospective study of 46 newly diag-
nosed cases.
Am J Clin Pathol.
2004 July;122(1):94–9.
3. Robert ME, Tang L, Hao LM, Reyes-Mugica M. Pat-
terns of inflammation in mucosal biopsies of ulcerative
colitis: perceived differences in pediatric populations are
limited to children younger than 10 years.
Am J Surg
Pathol.
2004 Feb;28(2):183–9.
4. Odze R, Antonioli D, Peppercorn M, et al. Effect of
topical 5-aminosalicylic acid (5-ASA) therapy on rectal
mucosal biopsy morphology in chronic ulcerative coli-
tis.
Am J Surg Pathol.
1993 Sept;17(9):869–75.
5. Fefferman DS, Farrell RJ. Endoscopy in inflamma-
tory bowel disease: indications, surveillance, and use
in clinical practice.
Clin Gastroenterol Hepatol.
2005
Jan;3(1):11–24.