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94 Benign Anorectal Diseases
a
c
and specificity of EAUS was 100% for EAS
defects and 100% and 95.5%, respectively,for IAS
lesions. Sultan et al. [12] compared preoperative
ultrasonographic findings with intraoperative
results in 12 consecutive patients who underwent
surgical repair for fecal incontinence. EAUS correctly identified all sphincters defects at time of
surgery. Sentovich et al. [34] examined the accuracy and reliability of EAUS. In 22 incontinent
women with known anal sphincter injury, the
accuracy was 100%. However, in nulliparous
women, EAUS falsely identified sphincter injury
in 5–25% of normal anal sphincters. In this
group, intact internal sphincters were more
accurately predicted than intact external sphincters (95% vs. 85%). Overall,clinical agreement in
the interpretation of the ultrasound between
b
Fig. IV.16. Anterior external sphincter repair (a). Three-
dimensional images in the coronal plane demonstrating the
lower (b) and the upper (c) sling of the overlap
experienced ultrasonographers (interobserver
reliability) was good (81% agreement).
Agreement was significantly better for the IAS
(74%, fair) than the EAS (61%, poor; p=0.0002)
and in evaluating the distal anal canal (0–1.5cm)
(78%) than the proximal anal canal (2.0–2.5cm
from the anal verge) (48% agreement; p
<0.0001). However, Gold et al. [35] reported that
interobserver agreement for diagnosis of sphincter disruption was very good (k=0.80). There
was no disagreement with respect to combined
or isolated IAS tears although there was some
disagreement regarding isolated EAS tears.
Abramowitz et al. [36] demonstrated interobserver concordance in 98.9% of cases.
Three-dimensional (3-D) EAUS may improve
diagnostic confidence of detecting damage to the
Section IV • Endoanal Ultrasonography in the Assessment of Patients with Fecal Incontinence 95
a
Fig. IV.17. Large internal sphincter defect in the anterior part of the anal canal (a). Three-dimensional sagittal view showing
that this extends the full length of the internal sphincter, with a length of 29 mm (arrow) (b)
anal sphincter complex, and the relationship
between the radial angle and longitudinal extent
of a sphincter tear can be assessed [13]
(Figs. IV.17–20). An additional advantage of 3-D
reconstructions is the possibility of measuring
the length of the remaining intact sphincter muscle. Christensen et al. [37] investigated the differences between 3-D and two-dimensional (2-D)
EAUS in visualizing damage to the anal sphincter
complex. The overall agreement between two
observers was 98.2% using 3-D and 87.9% using
2-D. In our institution (unpublished data), we
assessed the differences between 2-D and 3-D
EAUS in defining the longitudinal extent of a
sphincter defect in 33 patients with fecal incontinence due to obstetrical injury. The longitudinal
extent of an EAS tear was graded as either proxi-
mal, central, or distal only, or a combination of
two levels or full-length involvement. Twodimensional EAUS localized the defect in the mid
anal canal in most patients (94%), and in two
patients, the defect was localized in the upper
plus mid or mid plus distal anal canal,respectively. After 3-D reconstruction, the defects were
localized the upper plus mid anal canal in four
patients (12%), in the mid anal canal only in 22
b
a
Fig. IV.18. Large internal sphincter defect in the left side of the anal canal (a). Three-dimensional coronal view showing that this
extends the full length of the internal sphincter, with a length of 25 mm (b)
b
96 Benign Anorectal Diseases
Fig. IV.19. Obstetric trauma with a well-defined defect of the external sphincter at 2 o’clock. Multiview reconstruction showing
the defect in the coronal (a), axial (b), and sagittal (c) planes
patients (67%), and in the mid plus distal anal
canal in six patients (18%). In one patient (3%),it
detected a full-length involvement. The overall
agreement between 2-D and 3-D EAUS was moderate (k=0.25) for EAS tears in the upper plus mid
anal canal, good (k=0.71) for mid anal canal only
lesions, and poor (k=0.14) for defects extending
to the mid plus distal anal canal or for full-length
involvement. Three-dimensional EAUS allows a
better evaluation of the longitudinal extent of
EAS defects and may improve the selection of
patients for surgical repair of the anal sphincter
complex,helping the surgeon to judge how far the
repair should extend.
West et al. [38] examined whether 3-D EAUS
measurements (EAS length, thickness, area, and
volume) can be used to detect EAS atrophy and
compared the results with MRI measurements.
Agreement between 3-D EAUS and endoanal MRI
was 61% for IAS defects and 88% for EAS defects.
However, correlation was poor for EAS atrophy,
suggesting that 3-D EAUS measurements are not
suitable parameters for assessing EAS atrophy.
EAUS is the anorectal physiology study most
likely to change a patient’s management plan.
Liberman et al. [20] reported that EAUS detected
anal sphincter defects in five (11%) of 45 patients
within the medical group of fecal incontinence
who changed from medical to surgical management. In the surgical management group, 7% of
patients changed from surgical to medical therapy because of normal EAUS findings, and 2%
changed from sphincteroplasty to neosphincter
surgery.
Section IV • Endoanal Ultrasonography in the Assessment of Patients with Fecal Incontinence 97
a
c
Fig. IV.20. Three-dimensional images with volume render mode showing the extent of a sphincter tear in different planes (a–d)
References
1. Stoker J, Halligan S, Bartram CI (2001) Pelvic floor
imaging. Radiology 218:621–641
2. Bartram CI (2003) Ultrasound. In: Bartram CI,
DeLancy JOL. Imaging pelvic floor disorders.Springer,
Berlin Heidelberg New York
3. Burnett SJD, Bartram CI (1991) Endosonographic variations in the normal internal anal sphincter. Int J
Colorect Dis 6:2
4. Williams AB, Bartram CI, Halligan S et al (2001)
Multiplanar anal endosonography – normal anal canal
anatomy. Colorectal Dis 3:169–174
5. Frudinger A, Halligan S, Bartram CI et al (2002)
Female anal sphincter: age-related differences in
asymptomatic volunteers with high-frequency
endoanal US. Radiology 224:417–423
6. Williams AB, Cheetham MJ, Bartram CI et al (2000)
Gender differences in the longitudinal pressure profile
of the anal canal related to anatomical structure as
demonstrated on three-dimensional anal endosonography. Br J Surg 87:1674–1679
7. Nielsen MB, Hauge C, Rasmussen OO et al (1992) Anal
sphincter size measured by endosonography in
healthy volunteers. Effect of age, sex and parity. Acta
Radiol 33:453–456
b
d
98 Benign Anorectal Diseases
8. Kumar A, Scholefield JH (2000) Endosonography of
the anal canal and rectum. World J Surg 24:208–215
9. Gold DM, Halligan S, Kmiot WA, Bartram CI (1999)
Intraobserver and interobserver agreement in anal
endosonography. Br J Surg 86:371–375
10. Enck P,Heyer T, Gantke B et al (1997) How reproducible
are measures of the anal sphincter muscle diameter by
endoanal ultrasound? Am J Gastroenterol 92:293–296
11. Thakar R, Sultan A (2004) Anal endosonography and
its role in assessing the incontinent patient. Best Pract
Res Clinic Obstet Gynaec 18:157–173
12. Sultan AH, Kamm MA, Talbot IC et al (1994) Anal
endosonography for identifying external sphincter
defects confirmed histologically.Br J Surg 81:463–465
13. Gold DM, Bartram CI, Halligan S et al (1999) Threedimensional endoanal sonography in assessing anal
canal injury. Br J Surg 86:365–370
14. Bollard RC, Gardiner A,Lindow S et al (2002) Normal
female anal sphincter: difficulties in interpretation
explained. Dis Colon Rectum 45:171–175
15. Rociu E, Stoker J, Eijkemans MJC et al (1999) Fecal
incontinence: endoanal US versus endoanal MR imaging. Radiology 212:453–458
16. Felt-Bersma RJ, van Baren R, Koorevaar M et al (1995)
Unsuspected sphincter defects shown by anal
endosonography after anorectal surgery. Dis Colon
Rectum 38:249–253
17. Vaizey CJ, Kamm MA, Bartram CI (1997) Primary
degeneration of the internal anal sphincter as a cause
of passive faecal incontinence. Lancet 349:612–615
18. Felt-Bersma RJ, Cuesta MA, Koorevaar M (1996) Anal
sphincter repair improves anorectal function and
endosonographic image: a prospective study. Dis
Colon Rectum 39:878–885
19. Voyvodic F, Rieger NA, Skinner S et al (2003)
Endosonographic imaging of anal sphincter injury.
Does the size of the tear correlate with the degree of
dysfunction? Dis Colon Rectum 46:735–741
20. Liberman H, Faria J, Ternent CA et al (2001) A
prospective evaluation of the value of anorectal physiology in the management of fecal incontinence. Dis
Colon Rectum 44:1567–1574
21. Gantke B, Schafer A, Enck P, Lubke H (1993)
Sonographic, manometric and myographic evaluation
of the anal sphincters morphology and function. Dis
Colon Rectum 36:1037–1041
22. Bennett RC, Friedman MHW, Goligher JC (1963) Late
results of haemorrhoidectomy by ligature and excision. BMJ 2:216–219
23. Speakman CT, Burnett SJ, Kamm MA, Bartram CI
(1991) Sphincter injury after anal dilatation demonstrated by anal endosonography. Br J Surg
78:1429–1430
24. Khubchandani IT, Reed JF (1989) Sequelae of internal
sphincterotomy for chronic fissure in ano. Br J Surg
76:431–434
25. Kennedy HL, Zegarra JP (1990) Fistulotomy without
external sphincter division for high anal fistula. Br J
Surg 77:898–901
26. Farouk R, Bartolo DCC (1994) The use of endoluminal
ultrasound in the assessment of patients with fecal
incontinence. J R Coll Surg Edinb 39:312–318
27. Burnett SJ, Spence-Jones C, Speakman CT et al (1991)
Unsuspected sphincter damage following childbirth
revealed by anal endosonography. Br J Radiol
64:225–227
28. Nielsen MB,Rasmussen OO, Pedersen JF, Christiansen
J (1993) Anal endosonographic findings in patients
with obstructed defecation. Acta Radiol 34:35–38
29. Stoker J, Rociu E, Zwamborn AW et al (1999)
Endoluminal MR imaging of the rectum and anus: technique, applications and pitfalls. Radiographics
19:383–398
30. Williams AB, Bartram CI, Modhwadia D et al (2001)
Endocoil magnetic resonance imaging quantifictaion
of external anal sphincter atrophy. Br J Surg 88:853–859
31. Nielsen MB, Dammegaard L, Pedersen JF (1994)
Endosonographic assessment of the anal sphincter
after surgical reconstruction. Dis Colon Rectum
37:434–438
32. Savoye-Collet C, Savoye G, Koning E et al (1999) Anal
endosonography after sphincter repair: specific patterns
related to clinical outcome. Abdom Imaging 24:569–573
33. Deen KI, Kumar D, Williams JG (1993) Anal sphincter
defects: correlation between endoanal ultrasound and
surgery.Ann Surg 218:201–205
34. Sentovich SM, Wong WD, Blatchford GJ (1998)
Accuracy and reliability of transanal ultrasound for
anterior anal sphincter injury. Dis Colon Rectum
41:1000–1004
35. Gold DM, Halligan S, Kmiot WA, Bartram CI (1999)
Intraobserver and interobserver agreement in anal
endosonography. Br J Surg 86:371–375
36. Abramowitz L, Sobhani I, Ganansia R et al (2000) Are
sphincter defects the cause of anal incontinence after
vaginal delivery? Results of a prospective study. Dis
Colon Rectum 43:590–598
37. Christensen AF, Nyhuus B, Nielsen MB,Christensen H
(2005) Three-dimensional anal endosonography may
improve diagnostic confidence of detecting damage to
the anal sphincter complex.Br J Rad 78:308–311
38. West RL, Dwarkasing S, Briel JW et al (2005) Can
three-dimensional endoanal ultrasonography detect
external anal sphincter atrophy? A comparison with
endoanal magnetic resonance imaging. Int J
Colorectal Dis 20:328–333
IV.3.
Update in Perineal Anatomy and its
Relevance to Obstetric Trauma
G.A. Santoro, L. Pellegrini, G. Di Falco
The prevalence of anal incontinence in women is
strongly associated with obstetric history [1–5].
However, the mechanisms by which obstetrical
events induce anal incontinence remain controversial [6–10]. The etiology of fecal incontinence
has largely been attributed to damage to the
innervation of the anal sphincter musculature
sustained during vaginal childbirth, and Snooks
et al. [11] could demonstrate the existence of
pudendal nerve injury in 60% of patients with
anal incontinence due to obstetric tearing. Sultan
et al. [5] found that although pudendal nerve terminal motor latency (PNTML) was significantly
prolonged after vaginal delivery, it was not associated with the defecatory symptoms, and Lee et
al. [10] reported that pathologic postpartum
PNTML recovers to the predelivery level within 2
months.
With the introduction of endoanal ultrasonography (EAUS), the role of anal sphincter disruption emerged, and the effect of pudendal nerve
injury during vaginal delivery became less important [5, 6, 12–20]. Anal sphincter lacerations
should be considered the main cause of fecal
incontinence in women after vaginal delivery [5,
6, 12–20] and are strongly associated with primiparity, macrosomia, abnormal presentation, prolonged second-stage labor, and operative vaginal
delivery [1, 2,6–8, 21,22]. Prospective studies [5,6]
before and after childbirth have also shown that
up to one third of women sustain a sphincter
defect that is not recognized after delivery but will
be the primary cause of anal incontinence in later
life. This late-onset incontinence is due to the
compensation of pelvic floor muscles in younger
women. With aging and weakening of these adju-
vant pelvic supports, however, these defects
become clinically evident [10, 22–24].
This chapter focuses on the mechanism of
delivery and its relevance to pelvic floor injuries.
We also review the role of EAUS in the assessment of anal sphincter injuries following obstetric trauma.
Mechanism of Delivery and its
Relevance to Pelvic Floor Injuries
The natural process of childbirth carries inherent
risks to the perineum. However,the precise mechanisms of anal sphincter injury during deliveries
have still to be elucidated [6–10].Labor is divided
into three stages: (1) first stage – start to full
dilatation of the cervix, (2) second stage – full
dilatation to birth of baby, and (3) third stage –
birth of baby to delivery of placenta. The fetus is
descending during first and second stages of
labor. The birth canal is formed by dilatation of
the cervix and vagina and by stretching and displacement of the muscles of the pelvic floor and
perineum. The bladder is pulled above the pubis
because of its attachment to the uterus; the urethra is stretched and the bowel is compressed. By
the end of the second stage, the birth canal has
been fully formed (Fig. IV.21). Descent continues,
and the occiput reaches the pelvic floor
(Fig. IV.22). The occiput rotates to the front (internal rotation) and the head become occipitoanterior (Fig. IV.23). This process of pushing the head
through the vaginal introitus results in downward
descent of the pelvic floor,and most of the uterine
pressure is direct toward the perineal body and
100 Benign Anorectal Diseases
Urethra
Bulbospongiosus muscle
White line
Levator ani muscle
a
{
Anus
Dilated birth canal
Ischial
spine
Ischial
tuberosity
b
Transverse perineal
c
muscle
Urethra
Vagina
Coccyx
Anus
Fig. IV.21. Schematic representation of
the birth canal at the end of the second
stage of labor (a). Canal from the outside
(b), and from hereback (c)
Section IV • Endoanal Ultrasonography in the Assessment of Patients with Fecal Incontinence 101
Fig. IV.22. Schematic representation showing mechanism of
labor in left occipitoanterior position: the occiput reaches the
pelvic floor
anorectum (Fig. IV.24). During the second stage of
labor, the structures of pelvic floor are at highest
risk of injury. Further descent of the fetus pushes
the head forward with a movement of extension,
and the occiput is delivered. Increasing extension
round the pubis delivers the bregma, brow, and
face (Fig. IV.24). Descent and delivery of the head
has brought the shoulders into the pelvic cavity.
The head on delivery is oblique to the line of the
shoulders and rotates to the natural position rela-
tive to the shoulders with a movement known as
“restitution” (Fig. IV.25a, b). Descent continues,
and the shoulders rotate to bring the bisacromial
diameter into the anteroposterior diameter of the
pelvic outlet. This descent and rotation causes the
head to rotate so that the occiput lies next to the
left maternal thigh (external rotation)
(Fig. IV.25c). The anterior shoulder now slips
a
Bladder
Cervix
beginning
to open
Fig. IV.23. Schematic representation
Normal
b
anus
showing mechanism of labor in left
occipitoanterior position: descent and
flexion (a); internal rotation (b)
102 Benign Anorectal Diseases
Physiological retraction ring
Upper
segment
(thick)
Lower
segment
(thin)
a
Bladder
Cervix fully dilated
Vagina distending
Anus stretching
b
under the pubis, and with lateral flexion of the
fetal body,the posterior shoulder is born. The rest
of the body follows easily. Two thirds of the cases
will deliver spontaneously as occipitoanterior
(Fig. IV.26).
Abnormal Presentation
If flexion of the head remains incomplete in
descent,then rotation of the occiput anteriorly on
the pelvic floor may not occur, and rotation will
occur posteriorly (occipitoposterior position)
(Fig. IV.27). The mechanism now is difficult, for
flexion of the head is restricted by the fetal chest.
The soft tissues are stretched more than in occipitoanterior, and the fetus is delivered face to pubis
(Fig. IV.28). Occipitoposterior position may lead
Fig. IV.24. Schematic representation of the mechanism of
pelvic floor injury during vaginal delivery (a). Uterine force
acts downward and the pelvic resistance upward (b)
to increased risk of pelvic floor injuries [22].
Moreover, the perineum is distended by the
occipitofrontal diameter, and often, delivery has
to be completed by large episiotomy, by forceps
rotation (Fig. IV.29), or by use of the ventouse.
The incidence rate of occipitoposterior delivery
is 12%.
Episiotomy
Episiotomy is an incision in the perineal body at
the time of delivery. There are three types of incisions (Fig. IV.30): (1) median – a linear surgical
incision is made is the midline of the vagina and
perineum to increase vaginal capacity; it is associated with a much higher rate of third-degree
injury [2, 7], (2) posterolateral – more difficult to
Section IV • Endoanal Ultrasonography in the Assessment of Patients with Fecal Incontinence 103
a
b
c
Fig. IV.25. Schematic representation showing mechanism of labor in left occipitoanterior position: delivery of head (a); resti-
tution (b); external rotation (c)
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