Intestinal ultrasound for monitoring postoperative Crohn’s disease: A systematic review and clinical implications

Table 1 Summary of key studies evaluating bowel wall thickness on intestinal ultrasound as a predictor of postoperative recurrence in Crohn’s disease

Ref.	Year	Design	Number	Site assessed	Timing	BWT threshold	Outcome predicted	Sensitivity	Specificity	Statistic
Andreoli et al[6]	1998	Prospective	41	NTI	Within 2 weeks of colonoscopy	> 5 mm	Endoscopic recurrence	81%	86%	Accuracy = 83%
Parente et al[1]	2004	Prospective	127	NTI	12 months post-operative	≥ 6 mm or < 40% reduction	Clinical recurrence	NR	NR	HR = 8.9
Rispo et al[7]	2006	Prospective	45	NTI	12 months	> 5 mm	Endoscopic recurrence (Rutgeerts ≥ i3)	94%	100%	NR
Pallotta et al[10]	2010	Prospective	58 (111 evaluations)	Anastomosis + NTI	6-24 months post- operative	> 3.5 mm (ICA) + > 3 mm (NTI)	Endoscopic recurrence	100% (for ICA > 3.5 mm)	NR	AUROC = 0.95 (combined)
Cammarota et al[8]	2013	Retrospective	196	Anastomosis	6-15 months post- operative	> 3 mm	Surgical recurrence	NR	NR	RR = 2.1

NTI: Neo-terminal ileum; ICA: Ileocolonic anastomosis; BWT: Bowel wall thickness; NR: Not reported; HR: Hazard ratio; AUROC: Area under the receiver operating characteristic curve; RR: Relative risk.