Lessons learned: Preventable misses and near-misses of endoscopic procedures

Table 1 Commonly missed lesions requiring second-look colonoscopy[10,14-16] or upper endoscopy[10,20,24]

Bowel segment	Lesions missed	Intervention to improve lesion detection
Anorectum	Anal/rectal cancers	Careful anorectal exam before and on scope insertion with retroflexion
	Anal fissures
	Recto-cutaneous fistulas
	Anal warts
Colon	Lesions in colonic folds (particularly sigmoid)	Careful exam between the folds of the colon, especially in sigmoid segment, consider using a cap
		Excellent, good, or adequate bowel preparation, supported by photography
	Right colon	Second look
		Retroflex in right colon
	Cecum (especially behind IC valve)	Document examination
		Examine behind the ileocecal valve
		Cecal intubation rate
Terminal ileum	Lesions in ileum	Intubate in the terminal ileum
Esophagus	Below UES lesions, i.e., squamous cell carcinoma	Careful examination of upper esophagus, slow scope withdrawal
	Distal esophagus, collapsed varices in volume depleted patient	Careful examination of distal esophagus and awareness of patient’s volume status
	Subtle lesions of Barrett segment	Adequate time for examination of the segment
Stomach	Cameron lesions, gastro-esophageal junction (especially challenging to detect/examine with large hiatal hernias)	Careful examination of gastro-esophageal junction and diaphragmatic hiatus with retroflexion of the scope
	Arteriovenous malformation, Dieulafoy’s lesions	Careful inspection between the gastric folds using a cap
Small bowel	Duodenal bulb	Examine all 4 walls of the duodenal bulb and
	Duodenal sweep	May need to use of a side view scope
	3rd and 4th part of the duodenum	Advance scope by reducing the loop into 3rd and 4th parts of duodenum

UES: Upper esophageal sphincter.