DEFECOGRAPHY

ANATOMY

Supporting structures of the female pelvis: fascia, ligaments, mm
Structures form 3 contiguous layers (sup to inf)
- Endopelvic fascia
- Pelvic diaphragm
- Urogenital diaphragm

ANGLES

Anorectal junction (ARJ):
- Point of taper of the distal rectum as it meets the anal canal; corresponds to the posterior impression of the transition b/n puborectal mm and levator plate.
- Focal angulation b/n inferior aspect of levator plate and superior aspect of puborectalis mm.
Anorectal angle (ARA):
- The posterior wall of ARJ serves as apex of ARA b/n the posterior border of distal part of rectum and central axis of anal canal
- Important for assessing pelvic diaphragm basal tone and ability to normally contract/relax
- NML measurements:
  - Rest: 108-127 degrees
  - Squeezing: decreases by 15-20 degrees
  - Straining & defection: increases by 15-20 degrees

LINES

PUBOCOCCYGEAL LINE

PCL is the plane of pelvic floor mm attachment; aka level of pelvic floor
Used as reference for measuring organ prolapse
- In healthy patients, pelvic organ movement in any phase is minimal and never >1 cm below the PCL
- Causal inclination of levator plate >10 degrees w/ respect to PCL is indicator of pelvic floor relaxation.
How to draw:
- Go to midline sagittal plane
- Draw line connecting the inferior border of pubic symphysis to the final coccygeal joint

H & M LINE

Used to grade the severity of pelvic floor relaxation at maximal strain during defectation
Both lines are dynamic, shrinking/elongating depending on degree of contraction/relaxation or pelvic floor mm.
H line / Hiatal Enlargement
- Represents AP width of levator hiatus
- How to draw:
  - Go to midline sagittal plane
  - Draw line from inferior border of pubic symphysis to posterior wall of rectum at the level of the ARJ
- NML < 6 cm
M line / Pelvic floor descent
- Distance of levator hiatus descent
- How to draw:
  - Go to midline sagittal plane
  - Draw perpendicular line from posterior aspect of H line to PCL
- NML < 2 cm

NML PELVIC FLOOR FUNCTION

At rest and Valsalva...
- the bladder base, upper third of the vagina, sigmoid, small bowel, and peritoneal reflection should all be above the level of the PCL.
- The ARJ should remain within 2 cm below the PCL.
At maximal squeezing the puborectalis contracts...
- ARJ is drawn anteriorly & superiorly
- ARA decreases by 15 to 35 degrees
During straining/defectation...
- the puborectalis relaxes
- ARJ moves posterior and inferior away from pubis
- ARA becomes more obtuse by 15 to 20 degrees

PELVIC FLOOR DYSFUNCTION

Spectrum of functional disorders that result from impairment of the ligaments, fasciae, and mm supporting the pelvic organs
2 components to pelvic floor dysfunction that are related and often coexistent but should be differentiated:
- Pelvic floor relaxation
- Pelvic organ prolapse

PELVIC FLOOR RELAXATION

Pelvic floor mm can be thought of as a hammock supporting the pelvic organs with the levator hiatus representing an opening in this hammor.
In pelvic floor relaxation, the hammock sags (descent) and its opening becomes stretched out (widening)
- Descent assessed by M line
- Hiatal widening assessed by H line

PELVIC ORGAN PROLAPSE (POP)

Abnormal protrusion of any pelvic organ below PCL
- Can be isolate or multicompartmental
- Dysfunction of all 3 compartments is common due to shared structural support
- Loss of levator ani mm bulk > 50% is 7x more likely to be present in patients w/ POP
Draw perpendicular lines from PCL to the following landmarks
- Anterior compartment: most posteroinferior aspect of bladder base.
- Middle compartment: most anteroinferior aspect of cervix or vaginal apex if hyst
  - Subtract 1 cm for nml downward movement during straining
- Posterior compartment: anterior aspect of ARJ
  - Subtract 3 cm for nml descent
Interpretation: rule of 3s
- < 3 cm = mild prolapse
- 3-6 cm = moderate prolapse
- >6 cm = severe prolapse

ANTERIOR COMPARTMENT

Goals:
- Detect the actual position and mobility of the bladder, bladder neck, and urethra
- Search for associated dz of lower urinary tract
  - 60% of urinary incontinence is 2/2 urethral diverticulum
- Assess for cystocele and urethral hypermobility separately!
  - Stress urinary incontinence can be masked by both.

CYSTOCELE

Abnormal descent of urinary bladder at rest or with straining as result of tears/stretching of the endocervical fascia
Diagnosed when inferior aspect of bladder is >1 cm below PCL
Sx: urinary frequency, urgency, incontinence, dysuria, pelvic pain.
In severe cases, bladder descent is accompanied by a clockwise bladder rotation and urethral prolapse /transverse orientation resulting in urethral kinking at the bladder neck

URETHRAL HYPERMOBILITY

Axis of the urethra in nml pt should always be vertical w/ respect to the pelvic floor and nearly parallel to axis of pubic symphysis.
Anterior angulation of urethra > 30 degrees from its resting axis indicated urethral hypermobility
Distinction from a large cystocele is important as large cystocele may mask the stress incontinence attributable to urethral hypermobility.

MIDDLE COMPARTMENT

UTERINE / VAGINAL VAULT PROLAPSE

Uterosacral ligaments provide major support to the uterus and upper vagina. Defects in pubocervical / rectovaginal fascia, parametrium, and paracolpium can contribute.
Measured by drawing a line from the anterior inferior cervical lip to the PCL or posterosuperior vaginal apex if hysterectomy

CULDESAC HERNIA

Can include...
- Fat = peritoneocele
- Small bowel = enterocele
  - Traction: when posterior culdesac is pulled inferior by prolapsing cervix or vaginal cuff
    - Pubocervical and rectovaginal fascia are separated
    - Vaginal epithelium is stretched and becomes very smooth w/o rugae
  - Pulsion: when small intestin distends rectovaginal septum
    - Produces mass hard to differentiate from high rectocele
- Sigmoid colon = sigmoidocele

POSTERIOR COMPARTMENT

RECTOCELE

Outpouching of rectal wall during defecation 2/2 weakening of support structures of pelvic floor (esp rectovaginal fascia)
Anterior rectoceles are much more common than posterior
Anterior is measured in AP dimension in relationship to the expected location of the anterior anorectal wall which can be approximated by the location of the anterior anal wall.
< 2 cm = mild, can be seen in asx pt
2-4 cm = moderate
>4 cm = large

RECTAL INTUSSUSCEPTION & PROLAPSE

2/2 chronic straining and damage to surrounding fascia
- Chronic straining in setting of rectal prolapse can lead to pudendal neuropathy, external anal sphincter atrophy, and fecal incontinence.
Intussusception = invaginations of rectal wall defined as...
- Intrarectal = confined to rectum
- Intra-anal = extend to anal canal
- extra-anal = pass beyond anal orifice
  - Extra-anal intussuspection = rectal prolapse
Internal intussusceptions are further divided into...
- Full-thickness = entire wall
- Mucosal = only the mucosa
Can be circumferential (both walls) or only anterior wall.

FECAL INCONTINENCE

Involuntary loss of fecal material at an inappropriate time or place
Can have multiple overlapping conditions including pelvic floor descent, intussuscpetions, rectoceles, enteroceles.
Assessment of the anal sphincter is important as abnormalities of the EAS can contribute (thinning, fatty atrophy, and frank defects)

PELVIC FLOOR DYSSYNERGIA

AKA anismus or spastic pelvic floor syndrome
Entity results from failure of relaxation or paradoxical contraction of the puborectalis mm during defecation.
Sx: constipation, prolonged and incomplete defecation as well as delay b/n opening of the anal canal and initional of defecation.
Often associated w/ anterior rectocele.
Findings during defecation include lack of normal pelvic descent, inability to evacuate, paradoxical decrease in the ARA 2/2 puborectalis mm contraction w/ anterior and superior displacement of the ARJ, and hypertrophy of the puborectalis resulting in a prominent impression on the ARJ.
Measurement of the ARA and attention to the puborectalis motion is important.

FUNCTIONAL SYNDROMES

DESCENDING PERINEUM SYNDROME

SPASTIC PELVIC FLOOR SYNDROME

SOLITARY RECTAL ULCER SYNDROME

Page updated

Google Sites

Report abuse