Applied Anatomy and Physiology of the Pelvic Floor. Dr David Tarver Consultant Radiologist, Poole

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1 Applied Anatomy and Physiology of the Pelvic Floor Dr David Tarver Consultant Radiologist, Poole

2 Pelvic Floor 1. Sacrospinous Ligament 2. Levator Ani A Puborectalis B. Pubococcygeus C. Iliococcygeus 3. Urogenital Hiatus 4. Anal Canal

3 Endopelvic fascia Layer of supporting fascia covering pelvic floor, attaching pubis to vagina/uterus (pubocervical fascia) and vagina to rectum (rectovaginal septum) Pubocervical fascia supports bladder (defect causes cystocoele) Rectovaginal binds vagina to rectum (defect causes enterocoele) Fascia inserts into perineal body

4 Clinical Examination Underestimates or misdiagnoses prolapse in 45 90% Poor at assessing underlying deficiencies in evacuation disorders Confusing when multiple compartments involved

5 Modalities for Assessment Static MRI Dynamic MRI (MR Proctography) Fluoroscopic Evacuation Proctography Endoanal Ultrasound Conventional and Transperineal Ultrasound Ano-Rectal Physiology

6 Sagittal Plane Ant Mid Post

7 Coronal Plane Anal Canal

8 Coronal Plane - Posterior

9 Axial Plane

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14 Rule of 3 s Mild <3 cm Moderate 3-6 cm Severe > 6 cm

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19 Obstructive Defaecation Mechanical Recto-rectal / Recto-anal intussusception Rectocoele Enterocoele Functional (Anismus) Paradoxical contraction of puborectalis and sphincter

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26 Oxford Scale Rectal Intussusception Grade 1 circumferential invagination Grade 2 mild descent not as far as ARJ Grade 3 descent into upper anal canal Grade 4 descent to lower anal canal Grade 5 protrusion through anal canal

27 Proctography Fluoroscopy or MRI? Which should I use?

28 Dynamic MR of Pelvic Floor MR Proctography

29 Dynamic MR Protocol 200 ml aqueous gel per rectum on table via Foley Assuming conventional scanner configuration, supine with legs parted, inco pads Ax T2 static 3 planes 10mm single slice dynamic truefisp 320 FOV, 384x269 res, up to 2 mins at 2/3 sec per image Relax, start scan, pull up pelvic floor, relax, bear down without evacuating, relax, expel. Repeat expel phase to evacuation if necessary

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31 Grade 2 Intussusception

32 Grade 3 Intussusception + Enterocoele

33 Grade 4/5 Intussusception+ Sigmoidocoele

34 Grade 3 Intussusception + Enterocoele

35 Anismus

36 Anismus

37 Anismus (subtle)

38 Cystocoele

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41 Fluoroscopic Proctography

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49 Grade 5 Intussusception + Enterocoele

50 Grade 3 Intussusception + Cystocoele

51 Sigmoidocoele

52 Anismus

53 Anismus

54 Pre and Post TransSTARR

55 Pre and Post Lap VMR

56 Pros and Cons Fluoroscopic Proctography Position representative of normal evacuation 15 min/ patient episode Ready access to fluoroscopy Higher spatial and temporal resolution (real time)? subtle signs better seen, particularly small movements of muscles BUT Only rectum, vagina and SB viewed directly, other structures inferred Ionising radiation (Ave 200cGy/cm2)

57 Pros and Cons MR Proctography Much higher contrast resolution showing all structures No ionising radiation BUT Supine/semi-recumbent, not natural so may miss abnormal signs occurring in normal position Not real time, each frame 2-3 secs, so could miss fine details and small movements 30 min/episode Relatively limited access to MR

58 Barium Proctography versus Magnetic Resonance Proctography for Pelvic Floor Disorders: A Comparative study. Pilkington, Nugent, Tarver, Thomas, Clarke, Lamparelli et al. Colorectal Disease: Oct 2012

59 MR v Fluoro Both modalities are effective Fluoroscopic Proctography appears to show full extent of pelvic floor disorder more reliably than MR Fluoroscopy quicker and more available MR better for visualising other midline pelvic structures MR has no ionising radiation

60 MR v Fluoro MR produces more visually compelling images, with better pelvic overview But, MR might underestimate extent of pelvic floor derangement Access to MR may be limited, particularly for larger pelvic floor practices with high through put

61 Endo-Anal Ultrasound Faecal incontinence Assessment post obstetric trauma (third degree tears and above) Fistula in ano Perianal pain

62 Endo-Anal Ultrasound

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64 Normal Sphincters

65 Thickened Internal Sphincter

66 Torn External Anal Sphincter

67 Fistula-in-Ano

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70 Parks Classification

71 Transsphincteric Fistula

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74 Transsphincteric Fistula

75 Extrasphincteric Supralevator Fistula

76 Congenital External Sphincter Anomaly

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79 Acquired Pelvic Floor Trauma

80 Thank you for listening!