Chapter4 The Anterior Compartmen49

Urethra

On translabial imaging, te urethra is evident as a vertical hypoechoic area

(see Figures 1…4.4). This ea is thoughtto include mucosa, vascular

plexus, and the urethral smooth musculature. Its hypoechoic appearance

is largely attributable to the fact that mucosal layers and smooth muscula-

ture run parallel to the incident beam (seeChapter 2). This is evident

wheneverthere is signi“cant urethral rotation, bcausea more perpendicu-

lar orientation of the urethra relative to the incident beam makes the struc-

ture more isoechoic and therefore less evident. The urethral rhabdosphincter

surrounds this hypoechoic structure and appears as a double hyperechoic

stripe on translabial ultrasound at rest, ventral and dorsal of the urethra

proper. Its appearance seems to vary markedly depending on the approach

used, i.

⁴⁴ transrectal45 or translabial/perineal.

Recent improvements in tissue discrimination have made ide

cation

much easier (seFigure 4.9).

In general, the rhab

sphincter seems more obvious in the axial com-

pared with the midsagittal plane, as evident from Figures 6.2 and 6.5…6.9

in Chapter 6. Thisis at least partly attributable to the relative ease with

which the human eye recognizes ring structures, a legacy of hundreds of

millions of years of predator…prey relationships. Clearly, a number of

authors, incuding this one, havm isinterpreted “ndings in the past.³⁵ On

principle, intraurethral ultrasound with transducers de

loped for intra-

vascular imaging should help in id

tifying urethral morphology and h

us determine what exa

y we are imaging. Several authors used such

44,46,47

⁴⁸ con“ rming that the

rhabdosphincter often shows sonograp

evidence of impaiment in stress

incontinent women, both in the sen

of reduced contra

ility as well as

changes in

hogenicity and integrity.⁴⁸ However, the very limited avail-

ability of such transduers means that these techniques are unlikely to

enter clinical practice in the near future.

Figure 4.9The urethral rhabh

ncter as imaged in the midsagittal plane (native imaging, left image) and on speckle reduction

imaging (right image). Improved tissue discrimination allows recognition of a structure that is oth

50 H.P. Dietz

Figure 4.10Hyperechoic urethral foci (ar

a patient with mixed urinary incontinence, a second-degree cystocele, and USI.

Office cyst

throscopy was n

. The foci are more evident on Valsalva (right image).

On translabial sanning at rest,the rhabdosphinctr appears hypere-

choic as the incidnt beamis perpendicular to those “bers. On tansvaginal

ultrasound, p

rts of this circular or near-circular structure are vertical to

the incident beam, others ae parallel, and this has resulted in spurious

“ ndings, lea

ing some authors toconclude that the rhabdosphincter is

The resolution of curretly used transduers for translabial imaging is

insuf“ cient to allow more than a global ass

ment of the dimensions of

the urethra,but occasionally abnor

alities such as st

osis or diverticula

may beseen.⁴⁹ Although there have been attempts at quantitative assess-

50,51

the above-mentined artifacts

make the data ob

ined by this methodologysomewhat susp

t. To date,

no quantitative assessment of the urethr

rhabdosphincter as seen on

translabial ultrasound seems to ha

been undertaken, probably because

of resolution issues.

Hyperechoic foci withinthe urethra (see Figur4.10) are cmmon, may

be isolatedor multiple, and probably are attributable to cal

ed urethral

glands. Thee seems to be no association between symptoms or lower

urinary tract conditions andthe presence ofsuch foci.52

Bladder Wall Thickness

There has recentlb een renewedinterest in the quanti“cation of bladder

wall or detrusor wall thickness (BWT orDWT) by transvaginal and/or

translabial ultrasound.^53,54 Measurements are obtained after bladder emp-

tying and perpendicular to the mucosa, leading edge to leading edge (see

Figure 4.11), close to the midline as ide

ed by the urehra and bladder

neck. Originally, three sites were assessed by transvaginal ultrasound: ante-

rior wall, trigone, and dome of the bladder, and the mean of all three was

calculated. The author b

eves thatthe trigone (because it io f different

Chapter4 The Anterior Compartmen51

embryologic origin) is dif“cult to justify as a measurement location

compared withthe dome. In addition, there often is marked variation in

trigonal thicknessbetween the bladder neck and the interureteric ridge.

Another approach, currently used by the author, is to measure three sites

on the dome, wich can be performed either by translabial/introital or

by transvaginal ultrasound. Above a bladd

lling of 50 mL, DWT starts

⁵³ which is why in urogynecol

y measurements are usually

undertaken after bladder emptying. DWT measurement by translabial

ultrasound seems tobe highly reproducible, withan intraclass correlation

of 0.82 (CI0.63…0.91) fou

in a series o6 7 patients.⁵⁵

A DWT of more than 5 mm seems to be associated with detrusor overactiv-

⁵⁷ In our own data, DWT

is clearly higherin women with symptoms of urge incontinence and urody-

namically proven detrusoo veractivity, but the strength of the association

seems insufcient to beof much use in clinical practice.⁵⁸ IncreasedDWT is

likely the result of hypertrophy of the detrusor muscle, which is most evident

at the dome;this may be the cause of symptomor simply the effect of an

underlying abnormality.Although DWT onits own seems only moderately

predictive of d

trusor overactivity, the methom ay be clinicallyuseful when

combined with symptoms ofthe overactive badder.59 In young women, DWT

Figure 4.11DWT as

sured at the d

after bladder emptying: mean DWT is 2.5 (top left), 3.7 (top right), 4.4 (bottom left),

and 6.8 (bottom right). Measurements of 5 mm and above are associated with symptoms and signs of detrusor overactivity.

H.P. Dietz

⁶⁰ which supports

the hypothesis that increased DWT is indicative of acquired detrusor

hypertrophy, and probably the result of yars or deades of isometric con-

tractions against a cl

ed outlet. This is

so supported by the “nding that

a history of nocturnal enuesis in childhood is

sociated with increased

⁶¹ which implies

that, at least in sme women, increa

d DWT is attributable to an underly-

ing disorder that is either congenial or acquired in early chidhood.

Recently, DWT was shown to be a predictor of de novo detrusor overactivity

⁶² It is likely but remains to be proven that

determination of this parameter can contribute to the workup of a patient

with pelvic ”oor and bladder dysfunction, e.g., as a predictor of postopera-

tive voiding function or de novo/

orsened symptoms of the irritable

bladder. See also Appendix Case 3 for increased DWT in a young patient

with symptoms ofurgency, frequency, and urge incontinence.

LevatorAc

ivity

Perineal ultrasound has

en used for the quantication of pelvic ”oor

muscle function, both inwomen with stress in

ntinence and continent

controls,⁶³ as well as before and after childbir646,5 A cranioventral shift

of pelvic organs image

in the midsagittal plane is taken as evidence of a

levator contraction. The resulting displacement of the internal urethral

Figure 4.12A pelvic floor muscle contraction as documented by translabial ultrasound in the midsagittal plane. The left image

shows findings at rest; the right demonstrates cranioventral displacement of the bladder neck at man-mal pelvic floor muscle co

traction. (From ziHP, Ultrasound Imaging of the pelvic floor: 2D aspects. Ultrasound Obstet Gynaecol 2004; 23: 80…92, with

permission.)

Chapte4 The Anterior Compartmen53

Figure 4.13Quantification of pelvic floor

ontraction by measuring the reduction in hiatal dimensions (from 37 to 27 mm,

i.e., by 10 mm) or the increase in levator plate angle (from 51.37 to 74.37°, i.e., by 23°) on max

raction.

meatus is measured rel

ve to the inferoposterior symphyseal margin (see

Figure 4.12).

se 2b o

the Appendix demo

trates apelvic ”oor contrac-

tion in a healthy nulliparous volunteer.

Another means of quantifying levator activity is to measure reduction of

the levator hiatus in the midsagittal plane, or to determine the changing

angle of the hiatal plane (the •levator plate angleŽ) relative to the central

symphyseal axis (s

Figure 4.13). Narrowing

the hiatus without cranio-

ventral displacement of the bladder neck implies that the patient has

increased intraabdominal pressure weilcontracting the levator ani. This

is a common poblem and should be corrected by teaching proper tech-

Translabial ultrasound oservation of pelvic ”oor activity has hlped

validate the concept of hte knack,Ž e.., of a re”ex levator contraction

immediately before increases in intraabdominal pressure such as those

resulting from coughing.⁶⁸ Correlations between cr

ioventral shift of the

bladder neck on the one hand and palpation/perineometry on the other

hand have been

own to begood.⁶⁹ More recently, physiotherapists have

begun to ue transabdominal and translabial ultrasound to document

pelvic ”oor muscle activit, with one author concluding that the translabial

technique70 is probably more accurate for this indication.

Prolapse

antification

1,72

The inferior marginof the symphyss pubis serves as a convenient (if imper-

fect) line of reference against which the maximal descent of bladder, uterus,

cul-de-sac, and rectal

pulla on Valsalva ma

uver can be measured

54 H.P. Dietz

Figure 4.14Prolapse quacaition as demonst

in a schematic drawing of ultrasound find-

ings in the midsagittal plane. The inferior margin of the symphysis pubis is used as reference line.

(From DzeHP, Ultrasound Imaging of the pelvic floor: 2D aspects. Ultrasound Obstet Gynaecol 2004;

23: 80…92, with permission.)

(Figure 4.1) (see also Chapter 5 for uterine and posterior compartment

prolapse). Because the hu

s on Valsalva is gen

lly too large … especially

in women with proapse … to allow for simultaneous imaging of the entire

symphysis pubis and the posterior compartment, it is often not possible to

³ as refer-

ence for descent of a rectocele or enterocele. Needless to say, procidentia or

complete vaginal eversion generally preclude translabial imaging.

The main ue of imaging for prolapse quantc“ation may prove to be in

outcome assessmentter pelvic reconstuctive surgery, bth clinically and

for research. The elevation (and frequently distortion) of the bladder neck

74,75

(see Figure 4.15 and

Cases 7,

and 14 of the Appendix). Fascial and synthetic slings are visible

posterior to the trigone or the urethra (see Chapter 7 and Cases 11 and 14 of the

Appendix). Bulking agentsuch as Mcroplastique show up anterior, lateral,

and posterior to the proximal urethra (see Chapter 7). It has been demon-

strated that overel

ation of the bladder neck on colposuspension is unneces-

sary for cure ofUSI, and elev

ion may also have a bearing on postoperative

symptoms of voiding dsfunction and de novo detrusor overactivi74.^,75

Other Findings

Residual urine can conveniently be determined at the time of a routine

translabial pelvic ”oor assessmeņtalthough the formula used for this

purpose was developed for transvaginal ultrasound and has not yet been

formally validated for translabial use. It my be necessary to let the patient

perform a mild Valsalva maneuver to allow the most ventral part of the

dome to rotate downward. The two largest diameters are measured perpen-

dicular to each othr (see Figure 4.16), and the result in centimeters is

6,77

multiplied by 5.9. Deducting 14.9

according

to the formula X * Y * 5.

Š 14.9= residual volumein milliliters.

H.P. Dietz

A range of other abnormalities, incidental or expected, may at times be

imaged on translabial ultrasound, alth

gh a full pelvic ultrasound assess-

ment does ofcourse requirea transvaginal approach.Urethral divertic-

ula^78,79 (see Figure

4.17) er unlikely to be missed, especially if the

examination is perormed after the patient voids, and if care is taken to

inspect the paraurethral areas. Most are located dorsal to the urethra as in

Figure 4.17, but occasionally one may be found ventral or anterior to the

urethra, i.e., developing into the s

e of Retzius,as in Case 15 of the

Appendix. The main differential diagnosis is Gartner cysts, i.e., a cystic

remnant of the Wolf“an duct located in the vaginal wall (seeFigure 4.18

and Case9 of the Appendix), but it is generally possible to differentiate the

two becaue of their location relative to the urethra. In addition, urethral

diverticula are more likely to be symptomatic and tender on examination,

and often appear rather complex showing a convoluted or multicystic struc-

ture, often with internal echogenicity. Both urethral diverticula and Gartner

cysts may occasionally be confused with a nabothian follicle, but correct

identi“ cation of the cervixwill make such a mi

ake highly unlikely. A

Valsalva maneuvew ill lead to differential movement of the tissues and

help in correctly attributing cystic structures to the vginal walļ cervix,

bladder, or urethra.

Finally, labial cysts may be detected close to the transducer surface in

parasagittal planes, and the odd vagin

broma may cause circumscribed

isoechoic “ ndings within the vaginal wall. Occasionally, a bladder tumor

may be found (Figure 4.19), and intravesical stents and bladder diverticula

Figure 4.17Urethral diverticulum mimicking a cystourethrocele as seen on the right image taken on maximal Valsalva. The neck

of the diverticulum was situated close to the bladder neck, and this was confirmed on surgical exp

ra-

sound Imaginof the pelvic floor: 2D

s. Ultrasound O

Gynaecol 2004; 23: 80…92, with permission.)

58 H.P. Dietz

Figure 4.20Hematoma surrounding mesh after l

ic sacropolpexy (large arrow). There

is a second, smaller hematoma under a posterior colporrhaphy (small arrow). The patient was exam-

ined because of persistent postoperative voiding difficulty and pain. (From Dietz HP, Ultrasound

Imaging of the pelvic floor: 2D aspaso

und Obstet

aecol 2004; 23: 80…92, with

permission.)

can also bevisualized.³⁸ Postoperative hmatomata may be visible after

vaginal surgey or suburethral slings and at times explain clinical symp-

toms such as voiding dysfunction

persistent pain (ee Figure 4.20).

References

1. Schaer GN, Koe

i OR, Schuessler B, Haller U. Perineal ultrasound: determi-

nation of reliable examination procedures. Ultrasound Obstet Gynecol 1996;

7(5):347…352.

2. Dietz HP, Wilson PD. Anatomical assessment of the bladder outlet and proxi-

mal urethra using ultrasoundand videocystourethrogrphy. Int Urogynecol J

1998;9(6):365…369.

3. Dietz HP, Wilson PD. The i

uence of blad

r volume on the position and

mobility of the urethrovesical junction. Int Urogynecol J 1999;10(1):3…6.

4. Dietz HP, Clarke B. The inuence of posture on perineal ultrasound imaging

parameters. Int UrogynecolJ 2001;12(2):104…106.

5. Alper T, Cetinkaya M, Okutgen S, Kokcu A, Lu E. Evaluation of urethrovesical

angle by ultrasound in women with and without urinary stress incontinence.

Int UrogynecolJ 2001;12(5):308…311.

6. Martan A, Masata J, Halaska M, Voigt U. ltrasound imaging of the lower

urinary system in womenafter Burch colposuspension. Ultrasound Obstet

Gynecol 2001;17(1):58…64.

7. Dietz HP, Clarke B, Herbison P. Bladder neck mobility and urethral closure

pressure as predictors of genuine stress incontinence. Int Urogynecol J 2002;

13(5):289…293.

Chapte4 The Anterior Compartmen59

8. Dietz HP, Eldridge A, Grace M, Clarke B. Test-retest reliability of the ultrasound

assessment of bladder ck mobility. Int UrogynecolJ 2003;14(S1):S57…S58.

9. Reed H, Watereld A, Freema

RM, Adekanmi OA. Bladder neck mobility in

continent nulliparous women: normal references. Int Urogynecol J 2002;13(suppl

1):S4.

10. Brandt FŢ Albuquerque CD, Lorenzato FR, Amaral FJ. Perineal assessment of

urethrovesical junction mbility in young continent females. Int Urogynecol J

2000;11(1):18…22.

11. PescherU M, Fanger G,

haer GN, Vod

sek DB, DeLancey JO, Schuessler B.

Bladder neck mobilityin continent nulliparous womn. Br J Ob

et Gynaecol

2001;108

):320

324.

12. Dietz HP, Eldridge A, Grace M, Clarke B. Pelvic organ descent in young nulli-

gravid women. AmJ Obstet Gynecol 2004;191:95…99.

13. Oerno A, Di

z HP. Levator co-activation is an important confounder of pelvic

organ descent on Valsalva. ICS Annual SciectM“ eeting 2006, Christchurch,

New ZealandA bstract.

14. van der Velde J, Laan E, Everaerd W. Vaginismus, a component of a general

defensive reaction. An investigation of pelvio or muscle activity during expo-

sure to emotion-inducing “ lm excerpts in women

th and without vaginis-

mus. Int UrogynecolJ 2001;12(5):328…331.

15. King JK, Fr

man RM. Is ante

tal bladder neck mobility a risk factor for

postpartum stress incontinence? Br J Obstet Gynaecol 1998;105(12):1300…

1307.

16. Martan A, Msata J, HalaskM , KasikovaE, Otcenasek M,

igt R. The effect

of increasing of intraabdominal pressuron the position ofthe bladder neck

in ultrasound imaging. Annual Meeting, International Continence Society

2001, Seoul,South Korea.Abstract.

17. Fritel X, Zbak K, Pigne A, Demaria F, Bena” JL. Predictive value of urethral

mobility before suburethral tape proc

ure for urinary stress incontinence in

women. J Urol 2002;168(6):2472…2475.

18. Liapis A, Ba

s P, Lazris D, CreatsaG. Tension-free vaginal tape in the man-

agement of recurrent stress incontinence. Arch Gynecol Obstet 2004;269(3):205…

207.

19. Baks P, Liapis A, Creatsas G. Q-tip test and tension-free vaginal tape in the

management of female

tients with genuine stress incontinence. Gynecol

Obstet Invest 2002;53(3):170…173.

20. Masata J, Martan

Svabik K, Drahoradova P, Pavlikova M, Hlasenska J.

Changes in ur

hra mobility after TVT operation [article in Czech]. Ceska

Gynekol 2005;70(3):220…225.

21. Diez HP, Wilson PD. The •iris effect•: how two-dimensional and three-

dimensional ultrasound can help us understand anti-incontinence procedures.

Ultrasound Obstet Gy

col 2004;23(3):267…271.

22. Diez HP, Hansell NK, Grace ME, Eldridge AM, Clarke B, Martin NG. Bladder

neck mobility is a heritable trait. Br J Obstet Gynaecol 2005;112(3):334…339.

23. Diez HP, Bennett MJ. The effect of childbirth on pelvic organ mobility. Obstet

Gynecol 2003;102(2):223…228.

24. Peschers U, S

er G, Anthuber C, DeLancey JO, Schuessler B. Changes in

vesical neck mobility following vaginal delivery. Obstet Gynecol 1996;88(6):

1001…1006.

25. Meyer S, De Grandi P, Hohlfeld P, Megalo A. The birth trauma: short and long

term effects of foreps delivery compared to spontaneous delivery on different

pelvic ”oor parameter. Int Urogynecol J 1999;10(S1):S1.

26. Diez HP, Clarke B, Vancaillie TG. Vaginal childbirth and bladder neck mobil-

ity. Aust N Z J Obstet Gynaecol 2002;42(5):522…525.

H.P. Dietz

27. Dietz HP, Eldridge AM, Grace ME, Clarke B. Does pregnancy affect pelvic organ

mobility? Aust NZ J Obstet Gynaecol 2004;44:517…520.

28. Meyer S, De GranPi, Schreyer A,

ccia G. The assess

t of bladder neck

position andmobility in continent nullipara, multipara, forceps-delivered and

incontinent women using perineal ultraound: a future of“ce procedure? Int

Urogynecol J 1996;7(3):138…146.

29. Dietz HP, Lanzarone V. Levator trauma after vaginal delivery. Obstet Gynecol

2005;106

07…712.

30. Digesu G,Toosz-Hobson P, Bidmead J, Cardozo LD, Robinson D. Pregnancy,

childbirth and urinary incontinence: Caesarean for all? Neurourol Urodyn

2000;19(4):508…509.

31. Balmforh J, Toosz-Hobson P, Cardozo L. Ask not what childbirth can do to

your pelvic ”oor but what your pelvic ”oor can do in childbirth. Neurourol

Urodyn 2003;22(5):540…542.

32. Dietz H

, Moore KH, Steensma AB. Antenatal pelvic organ mobility is associ-

ated with delivery mode. Aust N Z J Obstet Gynaecol 2003;43:70…74.

33. Diez HP, Lanzarone V, Simpson JM. Predicting operative delivery. Ultrasound

Obstet Gynecol

06;27(4):409…415.

34. Schaer

, Perucchini D, Munz E, Peschers U, Koechli OR, DeLancey JO. Sono-

graphic evaluation of the bladder ne

in continent and sress-incontinent

women. Obstet Gynecol 1999;93(3):412…416.

35. Dietz H

, Clarke B. The ur

hral pressure pro“le and ultrasound imaging of

the lower urinary tract. Int Urogynecol J 2001;12(1):38…41.

36. Huang W

, Yang JM. Bladder neck funneling on ultrasound cystourethrogra-

phy in primary stressurinary incontinence: a sign associated with urethral

hypermobility and intrinsic sphincter deciency. Urology 203;61(5):936…941.

37. Gren TH. Urinary stress incontinence: differential diagnosis, pathophysiol-

ogy, and managment. Am J Obstet Gynecol 1975;122(3):378…400.

38. Tunn R,

tri E. Introital and transvaginal ultrasound as the main tool in the

assessment of urog

ital and pelvic ”oor dysfunction: animaging panel and

practical approach. Ultrasound Obst

Gynecol 20

;22:205…213.

39. Diez HP. What•s •normalŽ pelvic organ descent, and what•s prolapse? ICS

Annual Scienti“c Meeting 2006, Christchurch, New Zealand. Abstract.

40. Diez HP, McKnoulty L, Clarke B. Translabial color Doppler for imaging in

urogynecology: a prelimiary report. Ultrasound Obstet Gynecol 1999;14:144…

147.

41. Dietz H

, Clarke B. Translabial color Doppler urodynamics. Int Urogynecol J

2001;12(5):304…307.

42. Masata J, Mart

A, Halaska M, Kasikova E,

enasek M, VoitR. Detection

of Valsalva leak point pressure with colour Doppler: new method for routine

use. Neurourol Urodyn2001;20(4):494…496.

43. Kremkau FW. Diagnostic Ultrasound: Principles and Instruments. St. Louis:

WB Saunders; 2005.

44. Schaer

, Schmid T, Peschers U, DeLancey JO. Intraurethral ultrasound cor-

related with urethral histology. Obstet Gynecol 1998;91(1):60…64.

45. Kuo HC. Transrectal sonographic investigation of urethral and paraurethral

structures in women with stress urinary incontinence. J Ultrasound Med

1998;17(5):311…320.

46. Klein HM, Kirschner Hermanns R, Lagunilla J, Gunther RW. Assessment of

incontinence with intraurethral US: preliminary results. Radiology 1993;187(1):

141…143.

47. Kirschner Hermanns R, Klein HM, Mueller U, Schaefer W, Jakse G. Intra-

urethral ultrasoundin women with stress incontience. BrJ Urol 1994;74(3):

315…318.

Chapter4 The Anterior Compartmen61

48. Mitterberger M, Pinggera GM,

eller T, et al. Dynamic transurethral sonog-

raphy and 3D reconstruction of the rhabdosphincter and urethra. J Ultrasound

Med 2006;25:315…320.

49. Huang WC, Yang JM. Transvaginal sonography in the treatment of a rare case

of total urethral stenosis with a vesicovagin

stula. J Ultraound Med 2002;

21(4):4

63…467.

50. Toozs-Hobson P, Khu

r V, Cardozo L. Three-dimensional ultrasound: a novel

technique for investigating the urethral sphincter in the third trimester of

pregnancy. Ultrasound Obstet Gynecol 2001;17(5):421…424.

51. Robinon D, Toozs Hobson P, Cardozo L, Digesu GA. Correlating structure and

function: three-dimensional ultrasound of the urehral sphincter. Ultrasound

Obstet Gynecol2004;23272…276.

52. Yang JM, Hu

g WC. The signicance of urethral hperechogenicity in

female lower urinary tract symptoms. Ultrasound Obstet Gynecol 2004;24(1):

67…71.

53. Khullar V, Salvatore M, Cardozo L, Bourne T, Abbott D, Kelleher C. A novel

technique for measuring bladder wall thickness in women using transvaginal

ultrasound. Utrasound Obstet Gy

col 1994;:220…223.

54. Khullar V, Cardozo LD, Salvatore S, Hill S. Ultrasound: a noninvasive screening

test for detrusor instability. Br J Obstet Gynaecol 1996;103(9):904…908.

55. LekskulchiO, Dietz HP. Normal values for detrusor wall thickness in young

Caucasian women. Inteantional Continence Society Annual Scie

c Meeting

2005, Montreal. Abstract.

56. Robinon D, Anders K, Cardozo L, Bidmead J, Toozs-Hobson P, Khullar V. Can

ultrasound replace ambulatory urod

amics when invest

ating women with

irritative urinary symptoms? BrJ Obstet Gynaec

2002;109

):145

148.

57. Yang JM, Huang WC. Bladder wall thickness on ultrasound cystourethrogra-

phy. J Ultrasound Med 2003;22:777…782.

58. Lekskulchai O,

etz HP. Detrusor wall thickness as a test for detrusor over-

activity in women. ICS Annual Scientic Meeting 2006, Christchurch, New

Zealand.

59. Soligo M, Khullar V, Salvatore S, Luppino G, Arcari V, Milani R. Overactive

bladder de“ nition and ultrasound measurement of bladder wall thickness: the

right way without urodynamics. Neurourol Urodyn 2002;21(4):284…285.

60. Vela M, Parsons M, Cardozo L. Does bladder wall thickness increase with age?

Int Urogynecol J 2005

6(S2)S100.

61. LekskulchiO, Dietz HP. Detrusor wall thickness in women with a history of

childhood nocturnal enuresis. ICS Annual General Meeting 2006, Christ-

church, New Zealnd. Abstract.

62. Robinson D, Khullar V, Cardozo L. Can bladder wall thickness predict post-

operative detrusor overactivity? Int Urogynecol J 2005;16(S2):S106.

63. Wijma J, Tinga DJ, Visser GH. Perineal ultrasonography in women with stress

incontinence and controls: the role of the pelvio or muscles.

necol Obstet

Invest 1991;32(3):176…179.

64. PescherU M, Schaer GŅDeLancey JO, Schuessler B. Levator ani function

before and aftr childbirth. Br J Obstet Gynaecol 1997;104(9):1004…1008.

65. Dietz HP. Levator function before and after childbirth. Aust N Z J Obstet

Gynaecol 2004;44(1):19…23.

66. Bo K, LarsoS , Oseid S, Kvarste

B, Hagen R, Jorge

n J. Knowledge about

and ability to do correct pelvic oor muscle exercises iw omen with urinary

stress inco

inence. Neurourol Urodyn 1988;7:261…262.

67. Dietz HP, Wilson PD, Clarke B. The use of perineal ultrasound to quantify

levator activity and teach pelvico”or muscle exercises.

t Urogynecol J Pelvic

Floor Dysfunct 201;12(3):166…168.

H.P. Dietz

68. Miller JM, Perucchini D,

rchidi LT, DeLancey JO, Ashton-Miller J. Pelvic

” oor muscle contraction dring a cough and decreased vesical neck mobility.

Obstet Gynecol

01;97(2):255…260.

69. Dietz HP, Jarvis SK, Vancaillie TG. The assessment of levator muscle strength:

a validation of three ultrasound techniques. Int Urogynecol J 2002;13(3):

156…159.

70. Thompson J, O•S

van PB, Briffa K,

umann P, Court S.

sessment of pelvic

” oor movement using transabdominal and transperineal ultrasound. Int

Urogynecol J PelviF loor Dysfunct 20 5;16(4):285…292.

71. CreightonSM, Pearce JM, Stanton SL. Perineal video-ultrasonography in the

assessment of vaginal

olapse: early observations. Br J Obstet Gynaecol

1992;99(4):310…313.

72. Diez HP, Haylen BT, Broome J. Ultrasound in the quacaition of female

pelvic organ prolaps

Ultrasound Obstet Gy

col 2001;1

5):511…514.

73. Schaer GN, Koelbl H, Voigt R, et al. Recommendations of the German Associa-

tion of Urogynecology on functional sonography of the lower female urinary

tract. Int UrogynecolJ 1996;7

):105

108.

74. Bombieri L,Freeman RM. Do bladder neck position and amount of elevation

in” uence the outcome of colposuspension? Br J Obstet Gynaecol 2003;110(2):

197…200.

75. Viereck V, Pauer HU, Bader W, et al. Introital ultrasound of the lower genital

tract before ad after colposuspension: a 4-year objective follow-up. Ultra-

sound ObstetGynecol 2004;23(3):277…283.

76. Haylen BŢFrazer MI, Sutherst JR, West CR. Transvaginal ultrasound in the

assessment of bladder v

mes in women. Preliminary report. Br J Urol 1989;

63(2):149…151.

77. HaylenBT. Veri“cation of the accurcy and range of transvaginal ultrasound

in measuring bladder volumes in wo

n. Br J Uol 1989;6

4):350…352.

78. Mouritsen L, Bernstein I. Vaginal ultrasonography: a diagnostic tool for

urethral diverticulum. Acta ObsteG ynecol Scand 1996;75(2):188…190.

79. Tunn R, Bergmann-Hensel U, Beyers

f D, Heinrich G, Fischer W, Hamm B.

Diagnosis of urethral dive

icula and periurethral masses [article in German].

Rofo 2001;1

(2):109…114.

The Central and Posterior Compartments

Anneke B. Steensma

ProlapsA ssessment

Translabial ultrasoundhas been utilizedfor prolapse quanti“cation, not just

for the anterior compartment, but in the assessment of central and posterior

compartmentas well.^1,2 The uterus itslf may be dif“cult to identify because

it is iso- to hypoechoic, similar to vaginal tissues. A specular (line-like) echo

often indicates the leading edge of the cervix. At times, nabothian follicles

help with identi“ cation of the cerix, but in postmenopausal women the

uterus may be so small as to be virtually invisible on translabial imaging,

even if thee is signi“cant descent. Thsame holds trueor a retroverted

uterus, especially if sign

cant rectal contets or a recocele shadowthe area

of interest, and a well-supported uterus may be outside theld of view,

in particular if higher-frequency transducers ae used. Needless to say, a

full sonographic asessment of the etrus requires trasvaginal scanning.

Despite all those limitations, however, the cervix can often be located trans-

labially (see Figure5.1 for a second-degree uterine prolapse), and the same

holds true for the apex of the vault after hysterectomy (see Figure 5.2).

The bladder neck or the leading edge of a cystocele is used for the quan-

ti“ cation of anteriorvaginal wall descent, the cervix or Pouch of Douglas

for the central compartment, and the most caudal aspect of the rectal

ampulla … or the leading edge of rectocele contents … for qca

ion of

posterior compartment descent. The inferior margin of the symphysis

pubis anchos a horizontal line of reference against which descent can be

measured (see Figures 5.1 and 5.5). Ultrasound qu

cation ofcentral and

anterior compartments seems to agrewell with clinical prolapseassess-

ment by the prolapse quantc“ation system of the

ternational continence

³, with correlations of r= 0.77 for uterine prolapse, =

0.72 for anteriorvaginal wall, and r = 0.53 for poserior vaginal wall pro-

lapse descri

d in a comparative stud2.The vault after hysterectomy may

also be visualized in

e midsagittal plane (see Figure 5.2), but can be dif-

“ cult to identify, especiallyif there isa rectocele or if the ampulla is unusu-

ally full.

Descent of the posterior compartment is associated with symptoms of

prolapse, althoughthe correlation is not as strong as for the anterior com-

64 A.B. Steensma

Figure 5.1Prolapse quantification by transperineal ultrasound. Measurements are against a hori-

zontal line through the inferior margin of the symphysis pubis. Clinically there is a second-degree

cystoceledasecond-degree uterine prolapse.

partment. In women with isolated posterior compartment prolapse, descent

of the rectal ampual or of rectocele contents to 15 mm below the symphysis

or below see

s to be associated with symptoms of prolapse and has been

proposed as a

toff for •signi“ cant descentŽ on the

is of receiver opera-

Figure 5.2The midsagltp

lane at rest in a patient after abdominal hyst=

vagina,

b = bladder). ehpouch of Douglas is outlined by intraperitoneal fluid.

Chapter5 The Central and Posterior Compartm

ROC Curve

symptomatic

1.0

Cutoffs:

0.8

…2mm

…1mm

0.6

…10m

0.4

asymptomatic

0.2

c = 0.821

0.0

…50

…40

…30

…20

…10

0.0

0.2

0.4

0.6

0.8

1.0

1-specificity

Figure 5.3Historams for maximurectal descent relative to the inferoposterior margin of the symphysis pubis, in millimeters

(left) in ymptomatic (gray) and sy

tic wo

n (black) and receiver operator curve (ROC) for rectal descent as a test for

symptom

c prolapse (right). Lines define proposed cutoffs.

AnteriorRectoele

Correlations between cl

ical prolapse grading and ultrasound may not be

quite as good for the posterior compartment as they are for cystocele or

uterine descent, but it is possible to distinguish between •trueŽ and •falseŽ

rectocele, i.e., a defect of the rectovaginal septum (see Figure 5.4) and

increased distensibility of the septum and/or perineal hypermobility

without fascial defects5 (see Figure 5.5). This distinction matters, because

both entities may produe symptoms of prolapse, but only •trueŽ rectoceles

are associated with sympmos of straining at stool, incomplete bowel emp-

tying, and vagnal digitation, i.e, symptoms of ob

ructed defecation.⁶

The traditional distinction among low, midlevel, and high rectoc7le

is not supported by ultrasound data. From experience to date, •true

Figure 5.4•TrueŽ rectocele with an obvious rectovaginal

apparent on Valsalva,

ing about 25 mm in depth.

The presumptive ms

of the defect are indicated by arrows.

66 A.B. Steensma

Figure5.5. Descent ofethrectal ampulla without actual herniation of rectal contents into the vagina, termed •perineal hyper-

mobility.Ž (Fromz

HP, Steensma AB. Posterior compartment prolapse on two-dimensional and three-dimensional pelvic floor

ultrasound:ethdistinction between true rectocele, perineal hypermobility and enterocele. Ultrasound Obstet Gynaecol 2005; 26:

73…77, with permission.)

rectocelesŽ or fascial defects seem to almost always be found in the same

area, i.e., very close to the anorectal junction, and they are usually trans-

verse. Quanti“cation involves me

urement of rectocele depth, using a line

extending the cranioventral aspect ofethinternal anal sphincter as a base-

⁵ as shown

in Figures 56 and 5.10. Rendered volumes at the level of the hiatus in the

Figure 5.6Small but typical defect of the rectovaginal septum at the level of the anorectal junction, imaged in the midsagittal

plane (le

and as seen on a rendered volume in the axial p=adep

th,

= width.

Chapter5 The Central and Posterior Compartm

axial plane, orC plane imaging in general, can show the total extent of the

defect and demonstrate asymmetries (see Figure 5.6).

⁸ but they

are more common in the parous.⁵ In some women, they clearly arise in

childbirth, and if they are present before the delivery, defects tend to

enlarge.⁹ Many are asym

omatic, but thee is a signicant association

between bo

l symptoms such as incomplete bowel emptying and manual

evacuation on the one

nd, and the presence and depth of defects on the

other hand.⁶ Routine posteior repair often results in reduction or distor-

tion of suchdefects, without achieving actual closure. Defect-spc

repair

tends to be more effective in closing defects but may not affect concomitant

perineal hypermobility. Major levatorplasty, as frequently performed in the

past, often creates a hyperechogenic scar plate in front of the defect.

PosterioR ectocele

Posterior rectocele is

id to be a cmmon “ nding in children with consti-

pation and evacuatory dysfunction but is rarely seen in adults. As in ante-

rior rectocele, thearea of defct is veryclose tothe anorectal junction, but

seems to de

lop posteriorly or dorsally (see Figure 5.7). At times, appear-

ances ae suggestive of an intussusception of the anal canal into the

rectum.

Enterocele

One of the main advantages of translabial ultrasound is the ease with which

rectocele ca

⁵ The latter isdiagnos

d if

there isa herniation of ”uid-containing peritoneum, small bowel, sigmoid,

Figure 5.7Posteri

rectocelethe le

l of the anorectal junction.

68 A.B. Steensma

Figure 5.8Enterocele as demonstrated in the midsagittal plane on maximal Valsalva. The hernia-

tion is filled by a l

f small bowel, giving a bull•s eye…like appearance. Peristalsis often puts the

diagnosis beyond doubt. In

ent, there alsa ismall rectocele.

or omentum anterior to the anorect

junction, separating the vagina from

the rectal ampula (see Figure 5.8). Hysterectomy is considered to be the

main risk factorfor enterocele, and the majority of patients will have other

concomitant pelvic ”oor abnormalities.

Enterocele is freq

ntly overlooked on clinical examination, and its rela-

tion to pelvic ”oor symptoms remais unclear. At defecogram, multiorgan

opaci“ cation is necess

y for the diagnosis of enterocele, and this exposes

the patient to a relatively high dose oradiation. Magnetic resonance

imaging (MRI) has the advantage of demonstrating all compartments as

well as the capability to perform a limited dynamic investigation, but MRI

is expensiveand not widely available.

With transperineal imaging it is relatively easy to detect enterocele. In

the midsagital plane, a maximal Valsalva will demonstrate downward

movement of io- to hyperechoic abdominal contents anterior to the

anorectal junction, withor without vault prolapse. Sm

l bowel peristalsis

may help with the identi“ cation of structures

lling the hernia

(see

Figure 5.8).

Functional Imaging

Most recently, colrectal surgeons have started to use translabial ultra-

sound to complement or replace defecography, although it seems t

rst

10,11

It is very likely that

ultrasound will become useful in eh clinical assessment of women with

symptoms of obstrcted defecation.

t just rectocele (anterior or poste-

Chapter5 The Central and Posterior Compartm

Figure 5.9Comparison3Df translalualtrasou

(A)and defecogr

B)at maximum levator contraction in a 57-year-old

patient.

rior) and enterocelecan be demonstrated using dynamic 2D or 3D ultra-

sound, anismusmay be evient as a spastic levator that does not allow

descent of pelvic structures during Valsalva. As in conventional proctogra-

phy, it is possible to measure the anorectal angle to assess the levator ani

complex during contraction and relaxation of the pelvi

oor and at strain-

ing. Figures

9 and 5.10 show comparisons of translabial ultrasound and

defecation proctography, on levator contraction (Figure 5.9) and on maximal

Valsalva (Figure 5.

), in a patient with symptoms of ostructed defecation

and a large rectocele.

Figure 5.10Large rect

e as seen on maximal Valsalva, in the same patient as in Figure 5.9. Both methods demonstrate a

rectocele of more than 3 cm in depth.

70 A.B. Steensma

Figure 5.11Incipient rectal prolapse in a patient after vaginal vault suspension and enterocele

repair.

Rectal Intussusception and Rectal Prolapse

On functional pelvic ”oor ultrasound imaging, rctal intussusception or

occult rectal proapse is occasionally demonstrated in women without any

symptoms of evac

tory dysfunction.However, themethod is also capable

of demonstrating sympto

tic rectal prolapse. Normally, the anal canal is

tubular, with little difference betw

n luminal diameters along most of its

length (see, e.g., Figures 5.9 and 5.10). In less marked cases of rectal intus-

susception or •occultŽ prolapse, rectal wall and small bowel enter the proxi-

mal anal canal,

rcing it openand producing an arrow-shaped distension

on Valsalva (ee Figures 5.1and 5.12). Tis appearance is pathognomonic

Figure 5.12Developmentaor ectal intussusception on Valsalva: There is an enterocele which initially compresses the rectal

ampulla (central image) and then invaginates the rectal mucosa and muscularis (right image) into the anal canal which opens up

in a typical conical configuration.

Chapte5 The Central and Posterior Compartm

Figure 5.13First-degree uterine descent, with the cervix •pluggingŽ the anal canal in a patient with obstructed defecation.

and very similar to images obtained odefecation proctograph1.2 If there

is overt rectal proapse, the enterocele will be seen toow”Ž through the

anal canal, inverting rectal mucosu,ntil the prolapse exits through the

external anal sphincter. The mximal depth of an intussusceptin may be

measured by conn

ting the most proximal aspects of te internal anal

sphincter and measuring to the apex of the intussusception (see Figure

5.11).

Apart from rectocele and rectal intussusc

ion or prolapse, pelvic

” oor ultrasound may identify other, less cmmon causes of obstructed

defecation. It appears aht an abnormally mobileanteverted uterus may

impinge on the rectal ampulla and virtually •plugŽ it on Valsalva, a situa-

tion that is termeda •colpoceleŽ by colorectal surgeons (see Figure 5.13).

This may cuse the sensation of incomplete emptying and prompt the

patient to strain at stool … which only makes matters worse, similar to the

situation in rectal intussusception. There may be no oth

nding that

more graphically illustrates how much we still have to learn about pelvic

” oor function … and how much pelvi

oor ultrasound can teah us as well

as our patient. Once the situation is demonstrated to the patient on

imaging, attemptsat behavior modi“cation may well be much more likely

to succeed.

Clearly, muchwork will have to be done in d

ning the roleof the new

method in the evaluation of wo

n with obstructed defecation, in particu-

lar in comparisonwith defecationproctography.

Anal Sphi

ter Imaging

The anal sphinct

is generally imaged by ena

nal ultrasound, using high-

resolution probes with a eld of visionof 360°. Thismethod is “rmly estab-

lished as one

the cornerstones ofa colorectal diagnostic workup for anal

incontinence and coveree xtensively in the colorectal and radiologic lit-

Because

the limited availability of suchprobes ingynecology,

A.B. Steensma

obstetricians and gynecologists have taken to using high-frequency curved

array probes placeexoanally, i.e

in the coronal rather

than the midsagittal plane as described for all other applications in this

text.

There ae advantages to this approach … not just from the point of view

of the patient. Eoanal imaging reduces distortion of the anal canal and

allows dynamic evaluation of the anslphincter and mucosa at rest and on

sphincter contraction, which seems to enhance thenition of muscular

² and good comparative

studies ae still lacking.

Figure 5.14 demonstrates normal

earances on tranabial imaging of

the anal sphinter complex in the coronal plane. The mucosa is visualized

as a hypere

oic area, often star-shaped, representing the folds of the empty

anal canal.20 The internal anal sphincter (IAS) is seen as a hypoechoic ring,

the external anal sphi

ter (EAS) as an echogenic structure surrounding

the internal sphincter.^19…21There may be some variation of appearances

depending on age

d hormonal status.¹³ On contraction, the anal canal

narrows slightly, the mucosal star may be less pronounced, and defects of

the sphincter will become more obvious.

Anal sphincter injuriesseem to occur mch more frequntly than pre-

viously reported, although this may well be attributable to ineffective

intrapartum detecion rather than covered, truly •occultŽ defec23.On

ultrasound, sphincter defects appear as a discontinuity of the ring struc-

tures of theEAS and/or IAS. In te coronal plane, defects are conveniently

described using a clock face notation. In the longitudinal plane, sphincter

defects can be described by measuring the length of the defect relative to

total sphincter length.

After repair of third- and fourth-degree tears, ultr

ound frequently

demonstrates residual defects (see Figures 5.15…5.17), and the extent of

Figure 5.14Tranalbial imaging of a normal anal sphincter at rest.

Chapter5 The Central and Posterior Compartm

Figure 5.15Full-thickness

ect in the external anal

ter (EAS) complex from 11 to 12

o•clock, as visuawi

ith translabial ultrasound

transverse or coronal pla=

internal

anal sphincter.

such incompletely or inadequately repaired defects seems associated

with decreased sphincre pressures and an increased risk of anal

incontinence.²⁴

Childbirth and obstetric trauma is by far the dominant cause of anal

sphincter defects. The main risk f

or is considered to beinstrumental

vaginal delivery.25 Anal incontinence is common after third- and fourth-

degree tears, evn if they are reco

ized and repaired atthe time ofinjury,

and can have a devastating effect on a woman•s quality of life. The condition

may have been underrep

ed because of the social stigma involved. Early

Figure 5.16Varying appances 6…8 weeks after repair of third-degree tears.

74 A.B. Steensma

Figure 5.17Defect of the internal

ternal sphincter complex as visualized in the transverse (coronal) (left) from 11 to 1

o•clock and in 50% of the IAS visualized in the longitudinal plane (midsagittal) (right) in a 60-year

severe

fecal incontinence.

recognition and repair of sphincter injuries are likely to be of be

.²⁶

Pelvic ”oor ultrasound may well have a major role in the evaluation of

patients after traumatic delivery, but further studies are needed ton

the role of eoanal in comparison toendoanal ultrasound.

References

1. CreightonSM, Pearce JM, Stanton SL. Perineal video-ultrasonography in the

assessment of vaginal paopse: early observations. Br J Obstet Gynaecol 1992;

99(4):3

10…313.

2. Dietz H

, Haylen BT, Broome J. Ultrasound in the qua

cation of female

pelvic organ prolaps

Ultrasound Obstet Gy

col 2001;1

5):511…514.

3. Bump RC, Mattiasson A, Bo K, et al. The standardization of terminology of

female pelvic organ prolapse and pelvico”or dysfunction. AmJ Obstet Gynecol

1996;175(1):10…17.

4. Dietz HP. What•s •normalŽ pelvic organ descent, and what•s prolapse? ICS

Annual Scienti“c Meeting 2006, Christchurch, New Zealand.

5. Dietz HP, Steensma AB. Posterior compartment prolapse on two-dimensional

and three-dimenional pelvic ”oor ultrasound: the distinction between true

rectocele, perineal hypermobility and enterocele. Ultrasound Obstet Gynecol

2005;26:73…77.

6. Dietz HP,Korda A. Which bowel symptoms are most strongly associated with

a true rectocele? Aust N Z J Obstet Gynaecol 2005;45:505…508.

7. Davis K, Kmar D. Post

ior pelvic ” oor compartment disorders. Best Pract

Res Clin Obstet Gyna

2006;1

6):941…958.

8. Dietz HP, Clarke B. Prevalence of rectocele in young nulliparous women. Aust

N Z J Obstet Gynaecol 2005;45(5):391…394.

9. Dietz HP, Steensma AB. The role of childbirth in the actiology of rectocele. Br

J Obstet Gynaecol 2006;13:264…267.

10. Beer-

abel MMD. Dynamic transperineal ultrasound in the diagnosis of pelvic

” oor disorders: pilot study. Dis Colon Rectum 2002;45(2):239…248.

11. Beer-

abel M, Tesh

r M, Schechtman E, Zbar AP. Dynamic transperineal

ultrasound vs. defe

graphy in patients with evacuatory dic“ulty: a pilot

study. Int J Colorectal Dis 2004;19(1):60…67.

Chapter5 The Central and Posterior Compartm

12. Mellgren A, Bremmer S, Johansson C, et al. Defecography. Results of investiga-

tions in 2816 pati

ts. Dis Colon Rectum 1994;37(11):1133…1141.

13. Starck M, BohM, Fortling B, Valentin L. Endosonography of the anal sphinc-

ter in women of different ages and parity. Ultrasound Obstet Gynecol 2005;

25(2):169…176.

14. Damon H, Henry L, Bretones S, Mellier G, Minaire Y, Mion F. Postdelivery anal

function in primiparous females: ultrasound and ma

metric study. Dis Colon

Rectum 2000;43(4):472…477.

15. Williams AB, Bartram CI, Halligan S, et al. Alteration of anal sphincter mor-

phology following vaginal delivery revealed by multiplanar anal endosonogra-

phy. BJOG 20

;109(8):942…946.

16. Gold DM, Bartram CI, Halligan S, Humphries KN, Kamm MA, Kmiot WA.

Three-dimensional endoan

sonography in asessing anal ca

l injury. Br J

Surg 1999;86(3):365…370.

17. Frudinger A, Bartram CI, Halligan S, Kamm M. Examination techniques for

endosonography of the anal can

Abdom Imaging 19

;23(3):301…303.

18. Schaefer A,

ck P, Fuerst GĶ ahn T, FrielingT, Luebke HJA natomy of the

anal sphincters. Comparison of anen dosonography tomagnetic resonance

imaging. Dis Colon Reutm 1994;3(8):777…781.

19. Peschers U,DeLancey JO, Schaer GN, Schuessler B. Exoanal ultrasound of the

anal sphincter: normal anatomy and s

ncter defects. Br J Obstet Gynaecol

1997;104

):999…1003.

20. Timor-Tritsch IE, Monteagudo A, Porges RF,n

tos R. Simple ultrasound eval-

uation of the a

al sphincter in femalepatients usinga transvaginal transducer.

Ultrasound Obstet Gy

col 2005;2

2):177…183.

21. YaglS, Valsky DV. Three-dimensional transperineal sonography for evalua-

tion of the anal sphinctrcomplex: another dimension in understanding peri-

partum sphincter trauma. Ultrasound Obstet Gynecol 2006;27(2):119…123.

22. Cornelia L, Stephan B, Michel B,t

ine W, Felix K. Trans-perineal versus

endo-anal ultrasound in te detection of anal sphincter tears. Eur J Obstet

Gynecol Reprod Biol 2002;103(1):79…82.

23. Andrews A, SultanA, Thakar R,Jones P. Occult ansp hincter injuries…myth

or reality? BJOG 2006;113:195…200.

24. Starck M,

he M, Vale

in L. The extent of endosonograhic anal sphincter

defects aftr primary repair of obstetric sphincter tears increases over time

and is related to anal incontinence. Ultrasound Obstet Gynecol 2006;27(2):

188…197.

25. Sultan AH, Kamm MA, Hudson CN, Thomas JM, Bartram CI. Anal sphincter

disruption during vaginal delivery. N Engl J Med 1993;329(26):1905…1911.

26. Faltin DL, Boulvain M, Floris LA, Irion O. Diagnosis of anal sphincter tears to

prevent fecal incontinence: a randomized controlled trial. Obstet Gynecol

2005;106:6…13.

Axial Plane Imaging

Hans Peter Dietz

Levator Ani Complex

It is only very recently that imaging of eh levator ani has become feasible

using translabial ultrasound. The inferior aspects of the levator ani were

identi“ ed in early stu

¹ and translabial

² as well as on tranabial ultrasound using a

Voluson system3 but the focus of these reports was on the urethra and

paraurethral tissues. With translabial acquisition, the whole levator hiatus

and surrounding muscle (pubococcygeus and puborectalis) can be visual-

ized, provided acquisition angle

are at or aboe 70°. As

th magnetic

resonance imaging (MRI), it is currently impossible to distinguish the dif-

ferent components of te pubovisceralor puborectalis/pubococcygeus

complex. Several studies in nulliparous women have found no major asym-

⁴ and on utrasound,^5,6

supporting the hypothesis that signi“cant morphologic abnormalities of

the levator are likely to be evidence of delivery-related trauma. Contrary to

MRI data,⁷ no signi“ cant side differeces were foud on ultrasound biom-

etry, neither for thickness nor for area.

Regarding biometric parameters of the puborectalis/pubococcygeus

complex and the levator hiatus, there has been good agreement between

three-dimensional ultrasond and MRI, bothfor dimensions of the levator

hiatus^5,7 and levator thickness.5,8 In general, it is to be expected that ultra-

sound measure

ents shouldbe morereproducible because of the ease with

which measure

ents in the axial plane can be obtained in the plane of

minimal dimensions, whether at rest, on Valsalva, or on pelvoco”r muscle

contraction. Fgure 6.1 demonstrat

the process of ob

ining the plane of

minimal dimensions.

On MRI, the pane of minmal dimensions is virually impossble to

image reproduciblybecause of slow quisition speeds, even of single pre-

de“ ned planes. The latest software developments available for 3D/4D ultra-

sound such as

lume contrast imaging and speckle reduction imaging

should resultin a further improvement in resolution and therefore repro-

ducibility of ultrasound measurements. Diameter and area measurements

of the pubococcygeus…puborectalis complex may not bec

iently repro-

Figure 6.1Determination

iatal dimensions. The left-hand image shows the location of the plane of minimal dimensions as

seen on the mids

l view. This plane is tilted in a ventrocaudal to dorsocranial direction as eviden

ting

the im

e running from the posterior surface of the symphysis to the anterior margin of the most centa

lis

loop (white arr

). The rithimage represents the plane of minimal dimensions in the axial or C plane, with the vertical line

showing the location of the midsagittal plane. Arrows identify the minimal sagittal diameter of the hiatus.

Figure 6.2Area and diameter measuremenleva

tr hiatus [plane of minimal dim

at rest (left) and on Valsalva

(right)] in a

iparous volunteer. (From Dietz HP, Shek C, Clarke B. Biometry of the pubovisceral

y 3D

pelvic floor ultrasound. Ultrasound

aecol 2005;25(6):

85 , with permission.)

78 H.P. Dietz

and descet(because downward isplacement of organs may displace the

levatorlaterally), it is much more interesting that hiatal area at rest is asso-

ciated with pelvicorgan descent on Valsalva. These data constitute

rst

real evidence for the hypothesis that the state of the levator ani is important

⁹ even in the abse

e of levator trauma.

As a rule of thumba hiatal area of less than 25 2on Valsalva is unlikely

to be associ

ed with signi“cant prolapse. We classiayn area of 30…34.92cm

² as moderate, and 4+ cm2 as severe ballooning, with

² and above. Interestin

y, there ae nullipa-

rous women who show moderate to marked ballooning on Valsalva. Whereas

the highe

² the

author has recently document

ballooning to m

² in a nul-

liparous professional athlete with an asymptomatic three-compartment

prolapse and enterocel

without there being any evidence of an abnormal

connectivetissue phenotypeTo put this in perspective, the area required

².

Apart from static dimenions, relative enlargement of the hiatus on Val-

salva m

y be a measure of compliance or elasticity which mayu

ence the

progress of lbor, pelvic ”oor trauma, and future prolapse. However, child-

birth obviously has an effecton width and distensibility of the hiatus

(see Figure6.3). And “ nally, hiatal dimensions

e likely to affect treat-

ment outcome if (or when) treatment for pelvico”or dysfunction becomes

Figure 6.3Increase in hiatal dimensions on Valsalva after vaginal delivery (rendered volumes, axial plane).

Chapter6 Axial Plane Imaging79

Figure 6.4Avulsionjunry of the right pubovisceral muscle, on MRI (left) and 3D ultrasound (right). Although the images were

obtained in different patients, they illustrate the m

pattern of delivery-rel

vator trauma. The arrows indicate

vaginal detachment (top

) and detachment of the levator ani (bottom arrows). (MRI courtesy of Dr. Ben Adekanmi,

York, UK.)

necessary. The author believes that marked enlargement of the levator hiatus

on Valsalva redu

s the likelihood of successful pessary management and

probably makes

¹⁰ In

women that show a hiatal area

² one would

expect a high likelihood of posterior compartment prolapseafter a colpo-

suspension procedure … or a large cystocele after sacrospinous colpopexy,

because neit

r procedure would be expected to address the issue of exces-

sive distensibility of the levator hiat

. Clearly, much workwill have to be

done in this “ eld over the next decade, and pelvi

oor imaging is likely to

havea signi“cant impacton the development of prolapse surgery.

The most commonmorphologic abnormality of the levator ani, an

avulsion of the puboviscer

muscle off the pelvic sidewall, is clearly related

to childbirth (see Figures 6.4…6.6 and Cases 5, 10, 12, and 13 of the Appen-

dix) and is often palpable as an asymmetricsls of substancin the infero-

medial or ventrocaudal portion of the muscle. The digital detection of

morphologic abnormality seems to require sig

cant training however,

In a recently completed blinded study, the author found poor agreement

Technical issues also heepxplain the poor agreement found in this study.

In women with poorresting tone and minimal or absent voluntary func-

tion, defecs may be impossible to detect by digital examination. However,

a recent study using MR detection of levator defects demonstrated much

better agreement between imagingdanvaginal palpation, provided the

operators were trained speci“cally for this task.¹³

Chapter6 Axial Plane Imaging81

Thinning of muscle, which may be obvious on imaging, is harder to

palpate than gaps inthe continuity of the muscle or complete absence as in

avulsion injury. Having said that, biteral defects (see Figure 6.6, also

Figures 3.4 and 3.7, and Cases 10 and 13 of the Appendix) may be more

dif“ cult to palpate than unilateral avusion because of the lack of asym-

metry, and they are so much less common.

The detection of avulsion defects by translabial 3D/4D ultrasound seems

highly reproducible.¹⁴ Both rendered volumes

urface/transparency mode,

rendered from caudally tocranially) and single slices in the C or axial

plane may be used to help with the ide

cation of defecs. Therecent

development of tomographic ultrasound imaging (TUI) (see Figures 3.6,

3.7, 6.8, and

) is particula

ly useful in this regard beca

e it allows the

screening of oe 3D volume at a glance, especially once speckle reduction

algorithms have ben used to enhance resolutions in the axial plane.

Generally, defects seem boe most cleayl evident on levator contraction.

On Valsalva, de

cts may open up fu

her, but oncefull distension of the

hiatus is reachedthe defect is oftn obscured by attening of the area of

interest against te pelvic sidewall, particularly in women with sig

cant

prolapse.

Dif“ culties may arise in elderly women with marked urogenital

atrophy and/or scarrng, especially if voluntary

nction is absnt or with

very thin or atrophic muscle. Whenin doubt, the author has found

that measure

¹⁵ i.e., the distance

between the urethral lumen and the most medial aspect of the pubovisceral

muscle insertion, is helpful, with a gap of<2.6 mm likelyto indicate normal

anatomy (unpublished da

). Once oneis more famliar with the identi“ ca-

tion of defectsby vaginal palpation, an internal examination will further

help with the interpretation of ultrasound “ndings, especiallyif they are

equivocal.

Such defects of the pubovisceral muscle are surprisingly common for a

form of childbirth-related trauma that has receivevirtually no attention

to date. In a recently completed study, the author found that more than one

third of women delivering vaginally at an average age of 31.6 years had such

injuries,⁶ an incidence that is unexpectedly high compared with observa-

tions in older symptomatic wome

⁴ and previously published rates in

women who had their rst child at a younger age, both on clinical examina-

tion¹¹ and MRI.⁴ This discrepancy

y be explained by an association

between materal ageat “ rst delivery and the incidence of major levator

trauma^14,16 which is worrying gven the marked trend toward delayed child-

bearing in developed countriesIt seems likely tat women today run a

higher risk of sustaining signicant trauma to the lvator ani muscle, com-

pared with their mothers or grandmothers. This implies that urogynecol-

ogy„and urogynecologic imaging„is likely to be a growth area for the

foreseeable future.

Regarding causation, there seems to be an association with operative

delivery,⁶ but analogous to the situation with anal sphincter trauma, it

seems that precipatte delivery my also cause major levator trauma. This

impl ies that any association with length of second stage and other para-

meters indicating a dif“ cult delivery maynot be linear, making prediction

more dif“ cult.

H.P. Dietz

The clinical signi“cance of such def

s is becoming clearer. The author•s

own data sugg

t that levator avulsion is

sociated with anterior and

central compartment prolapse,14 but not with urodynamic “ndings or

symptoms of bladder dysfunction in a series of more than 300 primary

urogynecoogic assessments. Cross-sectional studies of levator anatomy in

asymptomatic and symptmatic older women are needed to determine

whether such abnor

alities are associated with clinical symptoms or con-

ditions in the general population. Another interesting question is whether

major morphologic abnormalities of the levator ani affect surgical out-

¹⁷ it appears that major

levator trauma, i.e., avulsion of the puborectalis/pubococcygeus from the

pelvic sidewall, sems to be associated with early presentation and recur-

rent prolapse after surgical repair.

Clearly, thereare different degrees of levator trauma. In the future we

should be able to distinguish not ju

unilateral and bilateral trauma, but

also isolated de

cts of the pubococcygeus or muscle, partial (Figure 6.5)

and/or complete avulsions puborectalis (Figure 6.6), and globalciencies

of the whoe levator (Figure 6.7) which are probably more likely to be

caused by neuropathy rather than direct trauma. In the meantime,

we may be able toquantify the extent oftrauma by using TUI which

allows both scoringaccording to the number of slices showing defects (see

Figure 6.8), and quantication of cranioventraland ventrodorsal defect

dimensions. Both defe

score and maxi

l width seem associated with

Figure 6.7Virtually complete absence of the pubovisceral muscle on the right side after Forceps

delivery.

Chapter6 Axial Plane Imaging83

Figure 6.8TUI of limdtebilateral levator trauma, affecting the lowermost aspects of the right pubovisceral muscle and more

cranial asps

on the left. The defect score is 6 (2 on right, 4 on left).

On a “ nal note, it appears thatthe literature to date contains no reports

of attempts at surgical correction.

is is nothing shot of amazing when

one consides that such defects may in fact be visible in the delivery suite.

Most avulsion injuries are occult,

t some become visible due to vaginal

tears, resulting in a typical appearance with the vagina detached from the

pelvic sidewall, te inferior public ramus and obturator fascia denuded of

muscle, ad the muscle retracted pararectally. We may have to learn how

to reattach the levator, a task that may require us to acquire some of the

skills of orthopedic surgens. Imaging will of course be instrumental in

documenting the success of failure of such attempts.

Paravaginal Supports

It has long been spec

ted that anterior va

nal wall prolapse and

stress uinary incontinence are at least

tly attributable to disruption

of paravaginal andør paraurethral support strctures, ie., the endopelvic

fascia and pubourethraligaments, atthe time of vaginal delivery.¹⁹ In

a pilot study using the now obsolete technology of freehand acquisition

of 3D volumes,alterations in paravaginal supports were observed in 5

21 women see

both ante- and postpartum, and the interobserver

H.P. Dietz

variability of the qualitative assessment of paravaginal supports was

shown to be good.² In light of current knowledge, however, the loss of

tenting documented in this study was probably at least partly attributable

to levator avulsion.

Structures supporting urethra and bladder can also be assessed by tran-

srectal or transvaginal 3D ultrasound using probes designed for pelvic or

prostatic imaging.^1,20 In a recent s

all series, researchers from Austria have

claimed that the endopelvic fascia may be evaluated directly by transrectal

3D ultrasound, describingdefects in an echog

c structure underlying

the bladder neck and proximal urethra. Such defects almost exclusively

occurred in vaginally parous wo

It remains to be shown whet

r loss of paravaginal tenting or defects

in suburethral/paraurethral echogenic structures are in fact equivalent

to what is clinically described as a •paravaginal defect,Ž a concept that is

22…24

In a recent sudy on 62 women

presenting

th pelvic ”oor disorders, only weakcorrelations were found

between a blinded clinical assessment for paravaginal defects and the

presence or abseec of tenting in single planes or rendered volumes

obtained by 3D translabial ultrasound, and even this weak correlation was

only seen on Valsalv2.⁵ This may be attributable to inadequate clinical

assessment techniqueor possibly an insuf“ciently sensitive imaging

method. Recent evidence suggests that the clinical assessment for para-

vaginal defecs has poor repeatabilit2.^6,27 However, another (if less likely)

explanation may be that true paravaginal defects are either not common

and/or irrelevant for anterior vaginal wall support.

Urethra ad Urethral Supports

The “rst use of 3D pelvic ”oor ultrasound, albeit with a transvaginal probe,

28,29

Although there seems to be

disagreement ato what has actuallybeen measured in some of the studies

20,28,30

it seems thathe volume of the hypechoic

structures surrounding the urethra (smooth muscle, vascular plexus, and

mucosa) is associat

with closure pressure.²⁸ On 3D ultrasound in the axial

plane, one is generally able to detect a circular hyperechogenic structure

surrounding the mid urethra (see Figure 6.9) which, judging from intraure-

thral ultrasound and axial plane MRI, corresponds to the striated urethral

sphincter.

It is less clear, however, whether obser

ion of static urethral

anatomy isof any clinical relevance. We ,after all, have inexpensive and

practical diagnostic toos to assess urethral function. In the author•s

opinion, resolutions atpresent ae not suf“cient for translabial ultrasound

to contribute to the as

ssment of urethral function. This may change with

the advent of sm

l parts 4D and matrix probes which will likely allow

much more detailedinsights into urethral anatomy, without distortion

and in a noninvasive manner. This probably also applies to urethral sup-

ports which are starting to be studied in more detail on MRI and

ultrasound.²¹

Chapter6 Axial Plane Imaging85

Figure 6.9TUI ia parous patient without bladder symptoms and normal pelvic floor anatomy. There is a hyperechogenic ring

structure (arrows) s

ding the midportion of the urethra in slices 1…4, i.e., extending over at least

the urethral rhabdosphincter.

Other Findings

At times, imaging in the axial plane can help clarify anatomic relationships

in more complex prolapsecases, especialif there is signi“cant asymme-

try. The extentof a cystoc

e may become more obvious (see Figure 6.10),

and side differences, e,gcaused by major levator trauma or neuropathy,

can be detecte

n the coronal plane (see Figure 6.11). Rectoceles are usually

clearly apparent because of their hyperechoic nature (see Figure 6.12 and

Case 6 of te Appendix).

Cystic structures in the vagina are more e

ly assessedon 3D ultra-

sound, especially regardgntheir relationship with the urethra (see Figure

6.13 and Cas9 of the Appendix for Gartner cysts, Case 15 for a urethral

diverticulum). The exact location oa pessary can also be determined

more easily on 3Dimaging, although Figure 6.14 is mainly given to

acquaint readers with the very dis

ct appearances of a ring pessary.

Theseappear virtually completely anechoic because of totale

ction of

incoming acoustic waves.Implants and suburethral slings will be dis-

cussed inChapter 7.

88 H.P. Dietz

Figure 6.14Prolapse pessaries may cause unusual and distinct sonographic patterns. In this case, a silicone ring pessary results

in complete reflection (and refraction) of incoming soundwaves, resulting in anechoic areas encompassing the pessary and an

acoustic shadow which is evident in the midsagittal and the coronal plane.

References

1. Wisser J, Scear G, Kurmanavicius J, Huch R, Huch A. Use of 3D ultrasound as

a new approach to assess obstetrical trauma to the pe

oor. Ultraschall Med

1999;20(1):15…18.

2. Dietz HP, Steensma AB, Hastings R. Three-dimensional ultrasound imaging of

the pelvic ”oor: the effectof parturition on paravaginal support structures.

Ultrasound Obstet Gy

col 2003;2

6):589…595.

3. Khullar V, Cardozo L. Three-dimensional ultrasound in urogynecology. In:

Merz E, ed. 3-D Ultrasound in Obstetrics and Gynecology. Philadelphia: Lip-

pincott Williams & Wilkins Healthcare; 1998:65…71.

4. DeLancey JO, K

ney R, Chou Q, Speights S, Binno S. The appearance of

levator ani muscle abnormalities in magnetic resonance images after vaginal

delivery. Obstet Gy

col 2003;101(1):46…53.

5. Dietz HP, Shek C, Clarke B. Biometry of the pubovisceral muscle and levator

hiatus by three-dmensional pelvic

or ultrasound. Ultrasound Obstet

Gynecol 2005;25(6):580…585.

6. Dietz HP, Lanzar

e V. Levator trauma after vaginal delivery. Obstet Gynecol

2005;106(4):707…712.

Chapter6 Axial Plane Imaging89

7. Fielding JR, Dumanli HŞchreyer AG,

al. MR-based thre-dimensional mod-

eling of the n

rmal pelvic ”oor in women: quanti“ cation of muscle mass. AJR

Am J Roentgenol 2000;174(3):657…660.

8. Tunn R, DeLa

ey JO, Ho

rd D, Thorp JM, Ashton-Miller JA, Quint LE. MR

imaging of levatorani musclerecovery following vaginal delivery. Int Urogy-

necol J 1999;10(5):300…307.

9. DeLanceyJO. Anatomy.In: Cardozo L, Staskin D, eds. Textbook of Female

Urology and Urogynaecology. London: Isis Medical Media; 2001:112…124.

10. Bary C, Dietz HP, Rane A. An independent audit of mesh repair for the treat-

ment of rectocele. 34th An ual Scienti“c Meeting of the International Conti-

nence Society 2004, Paris, France. Abstract 435.

11. Gainey HL. Postaprtum observation of pelvic tissue damage. Am J Obstet

Gynecol 1943;46:457…466.

12. Dietz HP, Hay-Smith J, Hyland G. Vaginal palpation and 3D pe

oor ultra-

sound in the diagnosi of avulsion defects of the levator ani. Neurourol Urodyn

2006;25(5):424…427.

13. Kearny R, Miller JM, Delancey JO. Interrater reliability and physical examina-

tion of the pubovisceral portion of the levator ani muscle, validity comparisons

using MR imaging. Neurourol Urodyn2006;25(1):50…54.

14. Diez HP, Steensma AB. The prevalence of major abnormalities of the levator

ani in urogynaecological patients.

J Obstet Gynaecol 2005;113:1…5.

15. Hoye L, Schierlitz L, Zou K, Flesh G, Fielding JR. Two- and 3-dimensional

MRI comparison of levatr ani structure, volume, and integrity in women

with stress inco

inence and prolap

. Am J Obstet Gynecol 2001;185(1):

11…19.

16. Kearny R, Miller J, Ashton-Miller J, Delancey J. Obstetric factors associated

with levator ani musle injury after vaginal birth. Obstet Gynecol 2006;107(1):

144…149.

17. AdekanmiOA, Freeman R,

ckett M, Jackson S. C

ocele: does anterior

repair fail because we fail to correct the fascial defects? A clinical and radiologi-

cal study.Int Urogynecol J 2005;16(S2):S73.

18. Diez HP. The classc“ation of major m

rphological abnormalities of the pubo-

visceral muscle. ICS 2006, Christchurch. Abstract.

19. DeLancey

. The anatomy of the pelvico”or. Curr Opin Obstet Gynecol 1994;

6(4):313…316.

20. Kuo H. The relationships of urethral and pelvi

oor muscles and the urethral

pressure meas

ements in women with stre

urinary incontinence. Eur Urol

2000;37(2):149…155.

21. Reisin

r E, Stummvoll W. Visualization of the endopelvic fascia by transrectal

three-dimensional ultasound. Int Urogynecol J 2006;17:165…169.

22. Ostrzenski A, Osborne NG. Ultraso

raphy asa screening tool for paravagi-

nal defects in wmen with stress incontinence: a pilot study. Int Urogynecol J

1998;9(4):195…199.

23. Martan A, MasataJ, Halaska M, Otcenasek M, Svabik K. Ultrasound imaging

of paravaginal defects in women with stress incontinence before and after

paravaginal defect repair. Ultrasou

Obstet Gyncol 2002;1

5):496…500.

24. Nguyen JĶHall CD, Taber E, Bhatia NN. Sonographic diagnosis of paravaginal

defects: a stan

rdization of technique. Int Urogynecol J 2000;11(6):341…345.

25. Diez HP, Pang S, Korda A, Benness C. Paravaginal defects: a comparison

of clinical examination and 2D/3D ultrasound imaging. Aust N Z J Obstet

Gynaecol 2005;45:187…190.

26. Se

l JL, Vassallo BJ, Kleeman SD, Silva WA, Karram MM. Paravaginal defects:

prevalence and accuracy of preoperative detection. Int Urogynecol J 2004;15(6):

378…383.

Imaging of Implant Materials

Hans Peter Dietz

Suburethral Slings

The imaging of synthetic implants may yet prove to be a major factor in the

uptake ofpelvic ”oor ultrasound in cinical practice, in particular because

currently used mesh implants seemto be much more difcult (if not

^1…3Syn-

thetic suburethral slings such as the tensionless vaginal tape (TVT), supra-

pubic arc tape

(Sparc), intravaginal slingplasty

(IVS), Monarc, and

transobturator TVT (TOT) have becomevery popular during the last 10

years4…7and are now the primary anti-incontinence procedures in many

developed countries. These slings are not without their problems, even if

biocompatibility is markedly betterthan for previously used synthetic

slings, a

d they differ from each other in someimportant aspects.

Imaging may be indicated in research, in order to determine location and

function of suchslings, and possibly even for assessing in vivo biomechani-

cal characteristics. Clinically, compli

ions such as re

rrence of stress

incontinence, voiding dysfunction,

osion, and postoperative symptoms

of the irritablebladder may bene“t from imaging assessment. Often, patients

will not remember the exact naturof previous incontinence or prolapse

surgery, and implants may be iden

ed in women whoare not aware of

their presenc, let alone their type.

Allografts such asPelvicol are impossible tvisualize after as short a

time as 2 monhs, and the echogenicity of fascial grafts seems to vary

widely. In contrast, most of the modern synthetic implant materials are

highly echogenic,with TVT, Spac, TOT, and Monar

usually being more

clearly visble thanthe IVS. Three-dimnsional (3D) ultrasound canlocate

the implant over its entire intrapelvic cours8,from the pubic rami to

behind the uethra, and bac

up on the contralateral side (ee Figure 7.1

and Case 14

the Appendix).

Variations in placement such as asymmetry, varying width, the effect of

tape division, ad tape twisting can be visualized (see Figure 7.2). The dif-

ference betw

n transobturator tapes and TVT-type implants, d

cult to

distinguish on 2D imaging (see Figu7e.3), is reaily apparenton rendered

volumes (see Figure 7.4 and Cases 11 and 14 of the Appendix). Another way

92 H.P. Dietz

Figure

7.1Rendered volume, axial

plane, sho

g the levator hiatus and a

TVT sur

nding te urethra. There is

a localized abnormality of the right

levatr ani that is of uncertain signifi-

cance. (From DieUz

trasound Imaging

of the Pelvic Floor: 3D aspects. Ultrasound

Obstet Gynecol 23

(6):615

5, with

permission.)

Figure 7.2Pelvic floor

ultrasound can document

vaiations in tape

placement, especially in

the axlaplane: usual

appearan

(A), very

tight placem

(B), tape

twisting(C, and findings

after tape division (arrow)

(D). (Modified from: Dietz

HP, Wilson PD. The Iris

effect: How 2D and 3D

volume uatsound can

help us understand anti-

incontinence procedures.

Ultrasound Obstet Gynecol

2004;23:2

271, with

permission.)