Table 1.

Endoscopic Precursor Lesions

	Non Stone Forming Endoscopic/Biopsy N = 19	CaOx N = 95	Uric Acid N = 23	p-value
% Plaque SA (median; IQR)	0.9 (0.6–1.5)	2.0 (1.0–4.3)	2.0 (1.0–3.1)	0.009
% Plug SA (median; IQR)	0.0 (0.0–0.0)	0.0 (0.0–0.7)	0.1 (0.0–1.0)	0.006
Number with plaque > 0 (%)	17 (90)	95 (100)	23 (100)	0.002
Number with plug > 0 (%)	2 (11)	43 (45)	13 (57)	0.006

Papillary and plaque data obtained at the time of endoscopic mapping.

Abbreviations: Calcium oxalate, CaOx; Surface area, SA