Magnetic resonance defecography assessment of obstructed defecation syndrome in patients with chronic constipation in a tertiary care hospital

Table 1 Standard definitions used for interpretation of magnetic resonance defecography

Terminology	Definition
Pubococcygeal line	Line between the inferior margin of the symphysis pubis and the tip of the coccyx (Figure 1)
Anterior compartment	The posterior and most inferior part of the bladder base is the reference point
Middle compartment	The most anterior and inferior aspect of the cervix or posterosuperior vaginal apex in patients who have undergone hysterectomy is the reference point
Posterior compartment	The anterior aspect of the anorectal junction is the reference point
H-line	Distance between the inferior border of the pubic symphysis and the posterior wall of the rectum at the level of the anorectal junction. It indicates the width of the levator hiatus (Figure 1)
M-line	Vertical line drawn perpendicularly from the PCL to the posterior end of the H-line. It indicates the degree of decent of the levator hiatus or the degree of pelvic floor laxity (Figure 1)
Cystocele	Abnormal descent of urinary bladder at rest/straining using the PCL as the reference line (Figure 2)
Urethral hypermobility	Urethra rotation of > 30° from rest, from the vertical to horizontal axis
Prolapse (uterine/vaginal/cervical)	Abnormal descent of the anteroinferior aspect of the cervix/posterosuperior vaginal apex from the PCL (Figure 2)
Peritoneocele and enterocele	Inferior herniation of the peritoneal pouch along the anterior rectal wall with an increased distance between the vagina and rectum and wide rectovaginal fossa. Enterocele-abnormal descent of small bowel loops below the PCL (Figure 2)
ARA	Angle between the midline of the anal canal and a line tangent to the posterior rectal wall. At rest the normal angle measures approximately 70°-134° (Figure 3)
Rectocele	Abnormal bulge of the anterior rectal wall into the posterior vaginal wall (Figure 2)
Rectal intussusception	Infoldings of the full thickness of the rectal wall into the rectum (intrarectal/recto-rectal) or into the anal canal (intra- anal/anorectal) or beyond (extra-anal/rectal prolapse)
Pelvic floor descent	Excessive descent of the pelvic floor at rest or during defecation
Anismus	Lack of pelvic floor descent/prominent puborectalis impression/failure of opening of the ARA

ARA: Anorectal angle; PCL: Pubococcygeal line.

Table 2 Radiological grading system

Condition	Grading for each condition
Cystocele
Prolapse (uterine/vaginal/cervical)	Grade 0: Absent
Enterocele	Grade 1: Mild/small (< 3 cm)
Peritoneocele	Grade 2: Moderate/medium (3-6 cm)
Pelvic floor widening	Grade 3: Severe/large (> 6 cm)
Pelvic floor descends
Rectocele	Grade 0: Absent
	Grade 1: Mild/small (< 2 cm)
	Grade 2: Moderate/medium (2-4 cm)
	Grade 3: Severe/large (> 4 cm)

Table 3 Baseline characteristics of patients by age (n = 57)

Characteristics	Frequency	%	mean ± SD	Range
Age in years
≤ 30	23	40.4	36.1 ± 13.3	17-73
31-40	17	29.8
41-50	8	14.0
51-60	6	10.5
≥ 60	3	5.3
Sex
Male	20	35.1
Female	37	64.9	N/A	N/A

N/A: Not applicable.

Table 4 Patient distribution by case according to magnetic resonance defecography findings (n = 57)

Magnetic resonance defecography findings	Number	%
Pelvic descent	54	94.7
Pelvic floor widening	45	78.9
Cystocele	37	65.9
Anorectal junction descent	54	94.7
Vaginal and uterine prolapse	22	59.4
Rectocele	45	78.9
Grade 1	15	26.3
Grade 2	23	40.4
Grade 3	7	12.3
Enterocele	15	26.3
Grade 1	12	21.1
Grade 2	3	5.3
Grade 3	0	0.0
Paradoxical contraction	4	7.0
Sigmoidocele	0	0.0
Peritoneocele	0	0.0
Intussusception	23	40.4
Intra-rectal	10	17.6
Intra-anal	11	19.3
Rectal prolapse	2	3.5
Urethal mobility
Normal	42	73.7
Hypermobility	15	26.3
Levator muscle symmetry
Symmetrical	44	77.2
Asymmetrical	13	22.8
Atrophy	2	3.5
Focal defects
Scarring	2	3.5
Ballooning	2	3.5
Focal eventration	1	1.8
Perineal body tear	2	3.5
Endopelvic facia
Not deformed	45	78.9
Deformed
Level I	4	7.0
Level II	3	5.3
Level III	5	8.8

The totals will not correspond to 100% because of multiple indications in individual patients.

Table 5 Evaluation of anorectal angle (n = 57)

Functional parameters	mean ± SD	Range	P value
Anorectal angle
Resting	97.09 ± 24.80	45-145
Squeeze (Kegel)	80.18 ± 23.36	35-138	< 0.001
Defecation	116.82 ± 31.23	53-185

Level of significance was set at P < 0.05. P value was determined by the paired Student’s t-test; Comparison between resting and defection.

Table 6 Patient distribution by anorectal angle condition (n = 57)

Resting			Kegel			Defecation
ARA condition	n	%	ARA condition	n	%	ARA condition	n	%
Normal	46	80.7	Expected narrowing	32	56.1	Expected widening	37	64.9
Narrowed	9	15.8	Diminished narrowing	25	43.9	Diminished widening	15	26.3
Widened	2	3.5				No change	1	1.8
						Paradoxical narrowing	4	7.0

ARA: Anorectal angle.

Table 7 Patient distribution by pelvic floor widening according to the H-line and M-line (n = 57)

The H-line, M-line, organ prolapse parameters	Resting			Defecation			P value
	n	%	mean ± SD	n	%	mean ± SD
H-line in cm
Grade 0	40	70.2	5.28 ± 1.43 (3.20-7.90)	12	21.1	7.56 ± 1.69 (4.40-12.20)	0.001
Grade 1	17	29.8		19	33.3
Grade 2	0	0.0		25	43.9
Grade 3	0	0.0		1	1.8
M-line
Grade 0	33	57.9	1.93 ± 1.07 (0.20-3.90)	3	5.3	5.17 ± 2.28 (1.0-9.60)	0.001
Grade 1	24	42.1		16	28.1
Grade 2	0	0.0		20	35.1
Grade 3	0	-		18	31.6
Cystocele
Grade 0	57	100		20	35.1		0.001
Grade 1	-	-		28	49.1
Grade 2	-	-		6	10.5
Grade 3	-	-		3	5.3
Uterine/vaginal prolapse
Grade 0	37	100		15	40.5		0.001
Grade 1	-	-		17	45.9
Grade 2	-	-		5	13.5
Grade 3	-	-		-	-

Level of significance was set at P < 0.05. P value was determined by the χ² test.