Rectopexy

The mesh is secured to the rectal wall and suspended superiorly from the sacral promontory. In women, the mesh can also attached to the superior vagina for additional support [5]. (Figures 1-3)

Fig 1: T1W sagittal MRI : normal rectopexy course

Fig 2: T1W MRI: normal rectopexy course

Fig 3: Axial MRI: normal rectopexy attachment at inferior rectum

Rectopexy Complications

The rectopexy mesh can cause secondary adhesions to the surrounding tissues and in more severe cases, fistulation. This example shows fibrotic changes at the insertion points as well as tethering of the rectum and vaginal vault. (Figure 4)

Fig 4: T2W sagittal MRI: abnormal fibrotic changes at the insertion points of the rectopexy

Tension-free Vaginal Tape (TVT)

TVT involves creating a sling underneath the urethra to provide support for stress incontinence. The sling comprises of two ‘arms’ which should traverse through the rectus muscles, above the pubis. Each arm runs in the retropubic space with a clear fat plane between the urinary bladder. [6] Posteriorly, the tape courses into the urethrovaginal space (where it may always not be seen).  (Figure 5 -7).

Fig 5: T2W axial MRI: expected course of the subcutaneous arms of the TVT through rectus muscles

Fig 6: T2W sagittal MRI: normal course of TVT posterior to pubis with a clear fat plane from the urinary bladder

Fig 7: T2W axial MRI: expected course in the urethrovaginal space

TVT Complications

Complications that may arise include misplacement, infection, mesh extrusion into the bladder, urethra or vagina.

The first TVT case shows the left subcutaneous arm is misplaced – compared to the right arm (green arrow) it lies more laterally and this can cause compromise of the ilioinguinal nerve. The patient had symptoms of constant groin pain. (Figure 8)

Fig 8: T2W axial MRI: Green arrow shows expected position of the right subcutaneous arm. Red arrow shows misplaced lateral position of the left TVT arm resulting in ilioinguinal nerve compromise.

The next patient was experiencing dysuria – the MRI shows urethral extrusion with focal oedema surrounding the urethra. Extrusion was confirmed on cystoscopy. (Figure 9 and 10).

Fig 9: T2W sagittal MRI: focal oedema of the urethra in keeping with extrusion

Fig 10: STIR sagittal MRI: again showing focal oedema of the urethra

Another example of extrusion, this time involving the bladder – the right arm of the tape is thickened and inflamed with clear extrusion into the bladder, also confirmed on cystoscopy. (Figure 11 and 12).

Fig 11: T2W axial MRI: extrusion of the right arm into the bladder

Fig 12: T2W sagittal MRI: again showing the extruded mesh into the bladder

Transobturator Tape (TOT)

The TOT was developed after the TVT to reduce the risk of bladder injury [7]. The tape has a transverse course and can often be difficult to visualise on MRI in the absence of any complications. It should pass above and through the obturator foramen, under the levator ani and pelvic fascia and then continue in the urethrovaginal space [8]. (Figure 13).

Fig 13: T2W coronal- the sling of the TOT can be seen at either side, this forms a 'U' shape and is best appreciated on serial images.

TOT Complications

The potential TOT complications are similar to those already discussed – this example shows marked inflammation of the right arm of the TOT with secondary oedema and inflammation of the right obturator internus muscle (Figure 14-16).

Fig 14: T2W coronal MRI: asymmetric inflammation of the right TOT arm

Fig 15: T2W axial MRI: the inflamed arm can be seen eroding into the muscle

Fig 16: T2W axial MRI: reactive inflammation/oedema within the right obturator internus