Indigo carmine (IC) dye staining has previously been reported to increase the
detection rate of diminutive flat neoplastic lesions which show a high rate of
severe dysplasie. Oral ingestion of an IC capsule with a polyethylene glycol
electrolyte lavage solution (PEG-ELS) was shown to be an effective chromescopy
technique in combination with magnifying colenoseopy. Our aim was to study the
utility of this technique at the same dose of IC previously used in routine nonmagnifying
colonosco W and to assess iftbe quality of colenosenpy was improved
with IC chromosco W
Methods: 100 consecutive colonoscopies were performed in 100 unselected
outpatients (45 F, 55M) with a mean age of 56.6 (20-82 yr), who gave written
infunned consenL Patients ingasWd an IC capsule containing 100 mg dye powder
during prepargien for colunoscopy at randomized timepoints: either before (A;
n=I0) the PEG-ELS, after ingestion of the first liter (EL; nffi2g), second liter (C;
n=32) or at the and of the lavnge (D; nffi30). Colonoscopies were performed with
an Olympus video-colunoscopa CF-100HI or C F- 1301. Endescopists (nffi4) were
asked to assess the shape, size and site of the lesions and to differentiale between
flat, pedanculated or sessile polyps. Contrast resulting from the IC dye was judged
as excellenL good, fair or weak. The endoscopist had to assess if colonuscopy
was improved by IC stain or not.
Results: The administration of IC capsules was well tolerated by all patients, no
side effects occurred. In 20% of patients results of IC staining were considered
fair to excellent, in 80% weak or insufficient. Contrast obtained was insufficient
in group A (100% weak) but was similarly weak in groups B (75%), C (75%) and
D (83%). Only 8% of cofonosenpies were jndged to have been improved by oral
IC staining. Decreased visibility due to coloration of liquid stools was the main
disadvantage of IC staining. Flat lesions were detected in 11 nut 0f44 patients
presenting with single up to multiple polyps or polypoid lesions. Histology
revealed normal sigmoid mucosa in 2/11 patients, hyperplastic polyps in 8111 and
an adenomatous polyp with low-grade dysplasia in 1/11 patients.
Conclusions: IC staining with orally ingested capsules often results in an
insufficient contrast in colonic mueosa independently of the time the capsule is
administered. In uuseleeted patients orally administered IC does not fecilitato
routine celonoseopy and does not seem to inar, sse the detection rate of flat lesions
when using non-mngnifying video-celonoscopes.