WHAT A MESH! A RADIOLOGIST’S GUIDE TO MR IMAGING OF PELVIC FLOOR SURGICAL REPAIRElizabeth Furey MD1, Gaurav Khatri MD1, April Bailey MD1, Maude Carmel MD2, Philippe Zimmern MD2, Ivan Pedrosa MD1

Departments of 1Radiology and 2Urology, UT Southwestern Medical Center, Dallas, TX

Sacral Colpopexy (SC) (Fig. 8)

• Mesh placed from sacral promontory to vaginal apex in ‘upside-down “Y” configuration’. Usually rightward curvature from superior to inferior.

• Variable extension of mesh components along anterior and posterior vaginal walls; posterior extent typically longer.

• Superior outcomes vs. sacrospinous or uterosacral fixation, and transvaginal mesh, but longer operative time, longer time to return to activities of daily living if performed via transabdominal approach9.

• Lower rate of vaginal erosion/extrusion (3-5%) compared with vaginal mesh kits (8-20%)8.

PELVIC ORGAN PROLAPSENative Tissue Repair

• Primary repair of native tissues +/- biologic grafts.

E.g. vaginal colporrhaphy for anterior or posterior prolapse; sacrospinous ligament fixation or uterosacral ligament suspension for apical prolapse.

Synthetic Vaginal Mesh (Fig. 2, 6, 7)

• Provide anterior and/or posterior support by anchoring to arcus tendineus (AT), coccygeus muscle-sacrospinous ligament complex (C-SSL), obturator membrane, and levator and inner thigh muscles8.

• Lower recurrent prolapse vs. native tissue repair, but mesh extrusion rate up to 18%; higher reoperation rate9.

• Higher rate of bladder perforation, increased blood loss, longer operating time, de novo stress incontinence (Prolift®* vs. anterior colporrhaphy )10.

• Other complications: recurrent or chronic infection, pain, dyspareunia.

E.g. Apogee™/Perigee™ (AMS, Minnetonka, MN); Avaulta® (C.R. Bard, Inc., Covington, GA); Gynecare Prolift®* (Ethicon, Bridgewater, NJ); Elevate™ (AMS, Minnetonka, MN); Pinnacle®, Uphold™ (Boston Scientific, Marlborough, MA). *Off the market.

Transobturator Tape (TOT) (Fig 3a, 4) )

• Transmuscular insertion through obturator and puborectalis muscles without violating retropubic space.

• More difficult to visualize on MRI than RP slings.

• Lower rate of bladder injuries and voiding difficulties vs. RP slings; higher likelihood for groin pain, vaginal injury, and mesh extrusion3.

• Original ‘outside-in’ (OI) technique - trocars passed into obturator foramen percutaneously and then through previously made midline vaginal incision4.

E.g. Monarc™ (AMS, Minnetonka, MN); ObTape* (Mentor-Porges, Le Plessis Robinson, France). *Off the market due to high

rate of vaginal extrusion and serious infectious complications5.

• Variant ‘Inside-out’ (IO) technique - sling placed via midline vaginal incision and then through obturator foramen using specialized instruments6.

E.g. TVT™ Obturator System (Gynecare, Ethicon, Bridgewater, NJ).

Single Incision Sling (Mini-sling) (Fig 3b)

• Similar to TOT, however arms of sling terminate at obturator foramen; do not course into foramen.

• Lower theoretical risk of organ, nerve and muscle injury during placement.

• Less post-operative pain vs. IO TOT, but higher risk of vaginal exposure, bladder/urethral extrusion, and operative blood loss (TVT™-Secur*)7.

E.g.- MiniArc™ (AMS, Minnetonla, MN); Ajust (C.R. Bard, Inc., Covington, GA); TVT™-Secur* (Gynecare, Ethicon, Bridgewater, NJ). *Off the market.

STRESS URINARY INCONTINENCE (SUI)Mid-urethral Sling proceduresRetropubic (RP) Slings

• ‘U’-shaped sling around mid urethra - arms extend anterosuperiorly into retropubic space.

• Potential complications: bladder perforation or blood loss/vascular injury3.

1. Transvaginal approach- Tension-free vaginal tape (TVT™, Gynecare, Ethicon, Bridgewater, NJ) (Fig. 1a, 2)

▪ Most widely used RP sling.

▪ Trocars passed via vaginal incision into retropubic space and then to ventral abdominal wall (“bottom-up”)3.

▪ Arms of sling course between bladder and pubic bone, and through suprapubic rectus fascia, 2.5 cm lateral to pubic symphysis, on either side of midline.

2. Suprapubic approach- Suprapubic Arch sling (SPARC™, American Medical Systems [AMS], Inc., Minnetonka, MN) (Fig. 1b)

▪ Similar to TVT, however placed “top-down” via suprapubic approach of trocars into retropubic space3.

▪ Arms of sling are approximately 1cm lateral to pubic symphysis on either side of midline.

• Pelvic floor disorders including pelvic organ prolapse (POP), chronic pelvic pain, defecatory dysfunction, and urinary and fecal incontinence affect nearly 1 in 4 women in the US1.

• >300,000 procedures performed annually in US for POP alone2.

• Surgical options: native tissue repair, urethral bulking agent injection, repair with biologic/absorbable materials or synthetic materials.

• Potential surgical complications: dyspareunia, chronic pain, extrusion, or recurrent infection.

• Imaging may help detect synthetic materials and associated complications.

• This review is intended to guide the radiologist in interpretation of these challenging post-operative cases.

• To illustrate magnetic resonance imaging (MRI) findings of various pelvic floor repair procedures including different types of urethral slings and vaginal mesh products.

• Various surgical options exist for repair of pelvic floor dysfunction.

• Patients with prior synthetic repair may present with various complications such as chronic pain, infection, extrusion, etc.

• Radiologists should be aware of the expected locations and appearances of various urethral slings and pelvic mesh kits/products.

• Radiologist checklist:

▪ Check particular brand of synthetic product.

▪ Look for hypointense linear/curvilinear structures on T2W images.

• RP Slings – periurethral, retropubic, suprapubic (traversing rectus fascia).

• TOT/Mini-Slings – periurethral, obturator foramen.

• Vaginal Mesh – anterior/posterior vaginal wall, rectovaginal space, arms traversing C-SSL or levator muscles into obturator foramen and/or ischiorectal fossa.

• SC mesh – sacral promontory to vaginal apex.

▪ Differentiating scar from mesh or tape may be difficult.

1. Nygaard I, Barber MD, et al. Prevalence of symptomatic pelvic floor disorders in US women. JAMA : The journal of the American Medical Association. 2008;300:1311-6.

2. Shah AD, Kohli N, et al. The age distribution, rates, and types of surgery for pelvic organ prolapse in the USA. Int Urogynecol J Pelvic Floor Dysfunct. 2008;19:421-8.

3. Roth CC, Winters JC, Woodruff AJ. What’s new in slings: an update on midurethral slings. Current opinion in urology. 2007;17:242-7.

4. Delorme E. Transobturator urethral suspension: mini-invasive procedure in the treatment of stress urinary incontinence in women]. Progres en urologie : journal de l’Association francaise d’urologie et de la Societe francaise d’urologie. 2001;11:1306-13.

5. Yamada BS, Govier FE, et al. High rate of vaginal erosions associated with the mentor ObTape. The Journal of urology. 2006;176:651-4.

6. de Leval J. Novel surgical technique for the treatment of female stress urinary incontinence: transobturator vaginal tape inside-out. European urology. 2003;44:724-30.

7. Nambiar A, Cody JD, Jeffery ST. Single-incision sling operations for urinary incontinence in women. The Cochrane database of systematic reviews. 2014;6:CD008709.

8. Nitti VW. Vaginal Surgery for the Urologist. Philadelphia, PA: Elsevier Saunders; 2012.

9. Maher C, Feiner B, et al. Surgical management of pelvic organ prolapse in women. The Cochrane database of systematic reviews. 2013;4:CD004014.

10. Altman D, Vayrynen T, et al. Anterior colporrhaphy versus transvaginal mesh for pelvic-organ prolapse. The New England journal of medicine. 2011;364:1826-36.

Fig 3. Illustrations in the axial plane demonstrate expected location of TOT (a) and single incision slings (b) relative to the pubic symphysis, urethra, vagina, and obturator foramina.

SlingUrethra

Vagina

SagittalMidline

Pubicsymphysis

ObturatorForamen

Rectum

a

SlingUrethra

Vagina

SagittalMidline

Pubicsymphysis

ObturatorForamen

Rectum

b Fig 5. 3D illustration of a vaginal mesh kit demonstrates components of the mesh anterior and posterior to the vagina. Arms from the anterior vaginal mesh extend into the obturator foramen. The posterior arms traverse the sacrospinous ligament.

Fig 8. Sagittal illustration (a) demonstrates expected course of SC mesh from sacral promontory to the vaginal apex. Sagittal T2W TSE image (b) in a 63 YO female with SC mesh demonstrates normal appearance of the mesh (orange arrows). Extension along the posterior vaginal wall is seen on this image (green arrow).COR T2W TSE image (c) in a 69YO female with suspected recurrent enterocele post SC mesh shows normal caliber and expected rightward curvature of the mesh (orange arrows). Sagittal T2W TSE image (d) in a 73YO female with clinical mesh erosion and foul smelling vaginal discharge demonstrates abnormal signal surrounding a markedly thickened SC mesh (yellow arrows). Purulent drainage was confirmed at surgery.

Sequence Imaging Plane

Slice thickness/gap (mm)

FOV (cm)

2D T2 TSE Sagittal 4/0.4 20

2D T2 TSE Fat suppressed Sagittal 4/0.4 20

2D T2 TSE Coronal 4/0.4 18

2D T2 TSE Axial 4/0.4 18

3D T2 TSE Axial 1.0(isotropic) 18

2D T1 IP/OP Axial 5/1 18

3D SPGR pre- and dynamic post-

contrastAxial 3/1.5 24

Footnote: TSE-Turbo Spine Echo; IP/OP- In phase/opposed phase; FOV-Field of View; SPGR-Spoiled Gradient Echo.

Fig 1. Illustrations in the axial plane demonstrate expected location of TVT (a) and suprapubic approach slings (b) relative to the pubic symphysis, urethra, and vagina.

2.5 cm

Sling

Urethra

Vagina

SagittalMidline

Pubicsymphysis

a

1 cm

SlingUrethra

SagittalMidline

Pubicsymphysis

Vagina

Rectum

b

Advantage FitTM Transvaginal Mid-Urethral Sling System

http://www.bostonscientific.com (9/19/2014)

Upsylon™ Y-Mesh and Colpassist™ Vaginal Positioning Device

http://www.bostonscientific.com (9/19/2014)

Pinnacle® Posterior Pelvic Floor Repair Kit

http://www.bostonscientific.com (9/19/2014)

Avaulta Solo® Graft Anterior

http://www.bardmedical.com (9/19/2014)

Elevate® Anterior and Apical Prolapse Repair System

http://www.amselevate.com (9/19/2014)

Uphold® Vaginal Support System

http://www.bostonscientific-international.com (9/19/2014)

Fig 2. 47YO female with vaginal mesh and RP sling. Axial T2Weighted (T2W) Turbo Spin Echo (TSE) images (a-d) demonstrate the sling as a “U-shaped” hypointense curvilinear structure in the peri urethral and RP spaces (blue arrows). The sling is seen traversing the rectus fascia on the left (blue arrows). Posterior vaginal mesh is visualized as a dark band along the anterior rectum, with the arms traversing the levator muscles and ischiorectal fossae (orange arrows). Coronal T2W TSE image (e) in a 49YO female with RP sling and vaginal mesh demonstrates slit-like on end appearance of the sling in the RP space (blue arrows), while the sagittal T2W TSE image (f) demonstrates linear appearance in the RP space (blue arrows). Anterior and posterior vaginal wall mesh is also seen on the sagittal image (orange arrows).

e

b c

f

a

d

Fig 4. 64YO female with worsening incontinence, bilateral groin and thigh pain since TOT placement. Axial T2W TSE images demonstrate periurethral hypointense bands traversing the levator muscles and extending into the obturator foramen bilaterally which could represent urethral tape or scarring (blue arrows). More inferiorly, distal arms of the sling are better seen on-end coursing between the obturator muscles (green arrows).

c d

a b a

Fig 6. 56Yo female with prior rectocele repair with mesh, presenting with left posterior vaginal wall tenderness. Axial T2W TSE images demonstrate normal hypointense ribbon-like thin right sided arm of posterior vaginal wall mesh (orange arrows), however the left arm (yellow arrows) is thickened particularly along the vaginal wall (green arrow). Focal thickening may suggest exuberant scarring or complications such as extrusion. Endoscopic examination confirmed mesh extrusion.

ba

Fig 7. 49YO female with RP sling and anterior and posterior vaginal mesh. Axial T2W TSE image (a) demonstrates redundant linear hypointense signal intensity bands along the anterior and posterior vaginal wall (orange arrows), thought to represent mesh and scar tissue. Arms of the RP sling are seen deep to the rectus abdominis (blue arrows). Coronal T2W TSE images (b, c) demonstrate the arms of vaginal mesh extending laterally through the levator muscles and then coursing in craniocaudad direction through the obturator foramen (orange arrows).

a b c

b

c d

Stress Urinary Incontinence (SUI)

Pelvic Organ Prolapse (POP)

Mid-urethral Sling procedures

Retropubic (RP) Slings

Transobturator Tape (TOT)

Single Incision Sling (Mini-sling)

Native Tissue Repair

Biologic/absorbable Graft

Synthetic Vaginal Mesh

Mesh Sacral Colpopexy

Anteror arms

Posterior arm

Sacrospinous Ligaments

Posterior arm

Anteror arms

PURPOSE

BACKGROUND

SURGICAL OPTIONS

REFERENCESPELVIC MESH MRI PROTOCOL

SUMMARY