Evaluating mucosal healing using colon capsule endoscopy predicts outcome in patients with ulcerative colitis in clinical remission

Figure 1 Effectiveness of cleansing at each site in the colon. A: Level of colonic cleansing was scored according to a four-point grading scale: excellent, good, fair and poor; B: Each site in the colon was scored: cecum, ascending colon, transverse colon, proximal left-sided colon and distal left-sided colon. The overall proportion of “excellent” plus “good” cleansing level was 73.3%.

Figure 2 Distribution of the activity score assessed by second generation of colon capsule endoscopy. A: Distribution of the Mayo endoscopic subscore (MES) assessed by second generation of colon capsule endoscopy (CCE-2); B: Distribution of the Ulcerative Colitis Endoscopic Index of Severity (UCEIS) assessed by CCE-2. We examined whether there was a difference in the distribution of each endoscopic activity score by CCE-2 in clinical activity index (CAI) 0 or CAI 1-4 groups using a test of independence. The distribution of MES by CCE-2 was statistically different between CAI 0 and CAI 1-4 groups, whereas that of UCEIS was not. Statistical analysis was performed by Pearson’s chi-square test. CAI: Clinical activity index.

Figure 3 Kaplan–Meier plots for relapse-free survival and exacerbation-free survival. A: Kaplan–Meier plots for relapse-free survival; B: Kaplan–Meier plots for exacerbation-free survival. The relapse-free survival rate was significantly higher in Mayo endoscopic subscore (MES) 0, 1 than in MES 2, 3 (P < 0.05; log-rank test), and in Ulcerative Colitis Endoscopic Index of Severity (UCEIS) 0-3 than in UCEIS 4-8 (P < 0.05; log-rank test). Furthermore, the exacerbation-free survival rate was significantly higher in MES 0, 1 than in MES 2, 3 (P < 0.01; log-rank test), and in UCEIS 0-3 than in UCEIS 4-8 (P < 0.01; log-rank test). However, there was no significant difference between clinical activity index (CAI) 0 and CAI 1-4 groups for both survival rates. MES: Mayo endoscopic subscore; CAI: Clinical activity index; UCEIS: Ulcerative Colitis Endoscopic Index of Severity.

Figure 4 Questionnaire survey about the acceptability of the second generation of colon capsule endoscopy. A questionnaire survey was carried out by all of the patients about the following five items: physical pain, mental distress, bowel preparation, next examination and overall acceptability. Each question comprised five-grade evaluations. CCE: Colon capsule endoscopy; CS: Colonoscopy.