Review of small-bowel cleansing scales in capsule endoscopy: A panoply of choices

Table 1 Computer dependent scales

Ref.	Computer or human dependent	Capsule endoscopy system	Type of preparation	Qualitative/quantitative scale	Reproducibility	Parameters evaluated	Entire video, segments of video or consecutive single frames	Time-consuming	Easy to perform1	Global assessment2
Van Weyenberg et al[6]	Computer dependent	PillCam	2 L of PEG	Quantitative	r = 1.0	Mean intensity values of the green and red channels of the small-bowel segment of the tissue colour bar	Tissue colour bar	No	ΔΔΔΔΔ	ΔΔΔΔ
Ponte et al[10]	Computer dependent	MiroCam	Clear liquid diet and overnight fast	Quantitative	r = 1.0	Mean intensity values of the green and red channels of the small-bowel segment of the tissue colour bar	Map view bar	No	ΔΔΔΔΔ	ΔΔΔΔ
Klein et al[8]	Computer dependent	PillCam	Clear liquid diet and overnight fast	Quantitative	Kappa = 0.9	Pixels of the small-bowel segment of the tissue colour bar	Tissue colour bar	No	ΔΔΔΔΔ	ΔΔΔΔ

¹Graduation from Δ to ΔΔΔΔΔ, with higher classifications corresponding to easier scales;

²Graduation from Δ to ΔΔΔΔΔ, with higher classifications corresponding to better scales. PEG: Polyethylene glycol.

Table 2 Human dependent scales

Ref.	Computer or human dependent	Capsule endoscopy system	Type of preparation	Qualitative/quantitative scale	Correlation coefficient	Parameters evaluated	Entire video, segments of video or consecutive single frames	Time-consuming	Easy to perform1	Global assessment2
Park et al[11]	Human dependent	PillCam	4 L of PEG	Quantitative	ICC = 0.80	Proportion of visualized mucosa and degree of obscuration by bubbles, debris, and bile	Consecutive single frames	Yes	ΔΔ	ΔΔΔ
QI - Brotz et al[5]	Human dependent	PillCam	Clear liquid diet and overnight fast	Quantitative	ICC = 0.47	QI based on percentage of mucosa visualized, fluid and debris, bubbles, bile/chyme staining, and brightness	Entire video	No	ΔΔΔΔ	ΔΔΔΔΔ
Spada et al[13]	Human dependent	PillCam	Clear liquid diet and overnight fast, or 2 L of PEG and simethicone	Quantitative	Kappa = 0.75-0.9	Proportion of mucosa visualized	Entire video	Yes	Δ	ΔΔΔ
Oliva et al[14]	Human dependent	PillCam	Clear liquid diet and overnight fast, or 25 or 50 mL/kg of PEG, and/or 20 mL of simethicone	Quantitative	Kappa = 0.89	Proportion of mucosa visualized	Consecutive single frames	Yes	ΔΔ	ΔΔΔ
van Tuyl et al[15]	Human dependent	PillCam	Clear liquid diet and overnight fast, or 1 L of PEG, or 2 L of PEG	Quantitative	Kappa = 0.78	Proportion of mucosa visualized	Segments of video	No	ΔΔ	ΔΔΔ
Caddy et al[16]	Human dependent	-	250 mL sodium picosulphate plus 500 mL PEG with or without erythromycin	Quantitative	Kappa = 0.3	Proportion of visualized mucosa	Entire video	No	ΔΔΔΔ	ΔΔ
Viazis et al[19]	Human dependent	PillCam	Clear liquid diet and overnight fast or 2 L PEG	Quantitative	-	Proportion of unclean mucosa due to intestinal debris	Entire video	Yes	ΔΔΔ	ΔΔ
Kantianis et al[22]	Human dependent	PillCam	2 and 4 L of PEG	Quantitative	-	Proportion of mucosa visualized	Consecutive single frames	Yes	Δ	Δ
Chen et al[23]	Human dependent	OMOM	Clear liquid diet and overnight fast, or 250 mL mannitol with or without simethicone	Quantitative	-	Proportion of mucosa visualized	Consecutive single frames	Yes	Δ	Δ
Rosa et al[25]	Human dependent	PillCam	Clear liquid diet and overnight fast, or 2 L of PEG with or without simethicone	Quantitative	-	Proportion of visualized mucosa	Entire video	Yes	ΔΔ	ΔΔ
Niv et al[26]	Human dependent	PillCam	Clear liquid diet and overnight fast, or NaP	Quantitative	-	Proportion of SBTT with invisible mucosa	Entire video	No	ΔΔΔ	ΔΔΔ
OAA - Brotz et al[5]	Human dependent	PillCam	Clear liquid diet and overnight fast	Qualitative	Kappa = 0.41	Overall assessment of small-bowel cleansing	Entire video	No	ΔΔΔΔΔ	ΔΔΔ
QE - Brotz et al[5]	Human dependent	PillCam	Clear liquid diet and overnight fast	Qualitative	Kappa = 0.20	QE based on percentage of mucosa visualized, fluid and debris, bubbles, bile/chyme staining, and brightness	Entire video	No	ΔΔΔΔ	ΔΔΔ
Albert et al[28]	Human dependent	PillCam	Overnight fast or simethicone	Qualitative	r = 0.89 (segment A)	Mucosal invisibility due to intraluminal bubbles	Segments of video	No	ΔΔΔ	ΔΔΔ
					and r = 0.79 (segment B)
Pons Beltrán et al[29]	Human dependent	PillCam	Clear liquid diet, or 90 mL NaP, or 4 L of PEG	Qualitative	Kappa = 0.38	Amounts of enteric residues	Entire video	No	ΔΔΔΔ	ΔΔΔ
Ninomiya et al[30]	Human dependent	PillCam	Clear liquid diet and overnight fast, or citrate magnesium	Qualitative	-	Bubbles, food residues and intestinal juice color	Consecutive single frames	Yes	ΔΔ	ΔΔ
Esaki et al[31]	Human dependent	PillCam	Simethicone or magnesium citrate	Quantitative and Qualitative	r = 0.77-0.88	Fluid transparency and proportion of non-visualized mucosa	Entire video	Yes	ΔΔΔ	ΔΔΔΔ
Dai et al[32]	Human dependent	PillCam	4 L of PEG or overnight fast	Quantitative and qualitative	Kappa = 0.56	Proportion of visualized mucosa and overall visibility	Segments of video	Yes	ΔΔ	ΔΔΔ
Lapalus et al[33]	Human dependent	PillCam	Clear liquid diet and overnight fast, or NaP	Quantitative and qualitative	r = 0.55-0.8	Proportion of visualized mucosa and amounts of enteric liquid and bubbles	Segments of video	No	ΔΔΔ	ΔΔΔ
Hooks et al[34]	Human dependent	PillCam	Clear liquid diet and overnight fast, with or without lubiprostone	Quantitative and qualitative	-	Proportion of mucosa visualized and amounts of enteric debris	Entire video and segments of video	No	ΔΔΔ	ΔΔΔΔ

¹Graduation from Δ to ΔΔΔΔΔ, with higher classifications corresponding to easier scales;

²Graduation from Δ to ΔΔΔΔΔ, with higher classifications corresponding to better scales. PEG: Polyethylene glycol; QI: Quantitative index; QE: Qualitative evaluation; OAA: Overall adequacy assessment; ICC: Intraclass correlation coefficient.

Table 3 Qualitative evaluation of small-bowel cleanliness developed by Brotz et al[5]

Qualitative evaluation
Excellent: Visualization of ≥ 90% of mucosa; no or minimal, fluid and debris, bubbles, and bile/chyme staining; no or minimal, reduction of brightness
Good: Visualization of ≥ 90% of mucosa; mild fluid and debris, bubbles, and bile/chyme staining; mildly reduced brightness
Fair: Visualization of < 90% of mucosa; moderate fluid and debris, bubbles, and bile/chyme staining; moderately reduced brightness
Poor: Visualization of < 80% of mucosa; excessive fluid and debris, bubbles, and bile/chyme staining; severely reduced brightness

Table 4 Grading scale of intestinal cleansing proposed by Ninomiya et al[30]

Residue elimination effect
4 points	No food residue at all, clear views
3 points	Some food residue present, not interfering with observations
2 points	Quite a lot of food residue, slightly hindering observations
1 points	Large amount of food residue, hindering observations
Intestinal juice clarity
4 points	Intestinal juice is clear, clear views
3 points	Intestinal juice is light colored and does not interfere with observations
2 points	Intestinal juice is light dark colored, slightly hindering observation
1 points	Intestinal juice is dark colored and interferes with observations
Froth reduction effect
4 points	No froth, clear views
3 points	Froth present, not interfering with observations
2 points	Quite a lot of froth, slightly hindering observations
1 points	Large amount of froth, hindering observations

Table 5 Small-bowel cleansing scale of Esaki et al[31]

Fluid transparency
Grade 1	Clear fluid without obscuring vision
Grade 2	Slightly dark fluid minimally obscuring vision
Grade 3	Opaque fluid partly obscuring vision
Grade 4	Turbid fluid severely obscuring vision
Mucosal invisibility1
Grade 1	< 5% in duration of > 50% bubbles or residues
Grade 2	5%-15%
Grade 3	15%-25%
Grade 4	> 25%
Overall image quality2
Grade A	3-5
Grade B	6-8
Grade C	9-12

¹The percentage indicates the proportion of length of time of video image in which air bubbles or food residues disturbed more than 50% of visualization and interpretation;

²The number indicates the sum of grades in each small intestinal segment.

Table 6 Small-bowel cleansing scale of Hooks et al[34]

Overall preparation
Excellent	Small bits of adherent solid material with clear or colored liquid
Good	Few liquids, small amounts of solid material, or dark fluid that did not interfere with the examination
Fair	Enough solid material or dark liquid to prevent a reliable examination
Poor	Large volume of residual food or fecal material precluding a complete examination
Proportion of mucosa visualized
4 points	> 75%
3 points	50%-75%
2 points	25%-49%
1 point	< 25%