Three-dimensional endoanal ultrasonographic assessment of an anal fistula with and without H2O2 enhancement

Table 1 Results of physical examination and 3D-EAUS findings in the identification of the primary fistula tract

	Classification based on surgical findings			Overall accuracy
	Intersphincteric (n = 26)	Transsphincteric (n = 34)	Suprasphincteric (n = 4)
Physical examination
Intersphincteric	201	9	0
Transsphincteric	7	231	2	68.7% (44/64)a
Suprasphincteric	0	2	11
3D-EAUS
Intersphincteric	241	4	0
Transsphincteric	4	291	1	84.4% (54/64)b
Suprasphincteric	0	1	11
H2O2 3D-EAUS
Intersphincteric	241	3	0
Transsphincteric	2	301	1	89.1% (57/64)c
Suprasphincteric	0	1	31

Data represent number of primary tracts.

¹Absolute agreement; P = 0.037 between a and b, P = 0.005 between a and c, P = 0.435 between b and c.

Table 2 Results of physical examination and 3D-EAUS findings in classification of secondary extensions

	Classification based on surgical findings (No. of secondary extensions detected)				Overall accuracy
	Absent (37)	Intersphincteric (7)	Ischiorectal (19)	Supralevator (3)
Physical examination
Absent	241	1	3
Intersphincteric	5	41	3	2
Ischiorectal	8	2	121		62.1% (41/66)a
Supralevator	0	0	1	11
3D-EAUS
Absent	321	0	2	1
Intersphincteric	2	51	1	2
Ischiorectal	3	2	161	0	81.8% (54/66)b
Supralevator	0	0	0	11
H2O2 3D-EAUS
Absent	331	0	1	1
Intersphincteric	1	51	1	0
Ischiorectal	3	2	171	0	86.4% (57/66)c
Supralevator	0	0	0	21

¹Absolute agreement; P = 0.01 between a and b, P = 0.001 between a and c, P = 0.482 between b and c.

Table 3 Results of physical examination and 3D-EAUS findings in localization of the internal opening

	Classification based on surgical findings (No. of internal openings detected)				Overall accuracy
	Anterior (12)	Left lateral (8)	Posterior (31)	Right lateral (6)
Physical examination
Anterior	61	0	0	0
Left lateral	2	51	1	0
Posterior	0	1	201	1	59.7% (34/57)a
Right lateral	0	0	2	31
3D-EAUS
Anterior	101	0	1	0
Left lateral	0	61	0	0
Posterior	0	1	261	0	84.2% (48/57)b
Right lateral	0	0	1	61
H2O2 3D-EAUS
Anterior	101	0	1	0
Left lateral	0	71	0	0
Posterior	0	0	281	0	89.5% (51/57)c
Right lateral	0	0	1	61

¹Absolute agreement; P = 0.004 between a and b, P = 0.001 between a and c, P = 0.406 between b and c.