This video demonstrates the utility of multi-compartment two-dimensional sonographic dynamic functional assessment of voiding dysfunction following sling surgery. Post-operative voiding dysfunction occurs after 5 to 15 percent of sling surgeries. Voiding dysfunction may present with symptomatic obstructed voiding where the diagnosis is evident. However, in patients with irritative symptoms, it is often difficult to accurately distinguish between urethral obstruction and bladder dysfunction. While some investigators suggest that avoiding pressure of greater than 20 centimeter of water and a peak urinary flow rate of less than 15 ml per second on neurodynamics signifies obstruction, often conclusive dynamic parameters suggesting obstruction are not available. Bladder outage obstruction can therefore be difficult to diagnose. At our center, two-dimensional functional assessment of sling dynamics using ultrasound has proven useful in assessing patients with voiding dysfunction following sling surgery. We use the BK Medical ProFocus UltraView for performing two-dimensional functional imaging. This includes the transperineal two-dimensional dynamic imaging with the 8802 transducer and endovaginal two-dimensional dynamic imaging with the 8848 transducer. Now, let us look at how a normal sling helps in achieving continence and compare with slings causing obstruction. This is a dynamic film in the sagittal plane obtained with the transperineal BK probe 8802. This is the bladder, the urethra, the symphysis pubis and the vagina. The trans-operator sling is seen as a slightly curved ecodent structure beneath mid urethra. At rest, the mid point of the sling lies more than 7 millimeters distance from urethral lumen. Therefore, the sling rests on the urethra without causing obstruction. On dynamic assessment, the sling and the urethra move in a concordant manner. The sling bends into a C-shape and achieves dynamic compression of the urethra during stress events without causing obstruction at rest. Now, let us look at a dynamic film in the sagittal plane with the endovaginal BK transducer 8848 in the vagina. Looking up at the anterior pelvic compartment, here you can see the bladder, the symphysis pubis and the urethra. The sling can be seen to lie beneath mid urethra without causing indentation of the urethra or impinging into it. On cough, the sling and the urethra can be seen to move in a concordant manner. Now, let us look at some case studies. Patient A, a 56 year old G2P2, underwent retropubic mid urethral sling surgery for mixed incontinence, stress greater than urge. At the 38 week follow-up visit following surgery, she reported more than 11 voids per day with progressive worsening of her urgency incontinence symptoms. She had three to four incontinence events per day. On urodynamic examination, though the detrusor pressure at peak flow on voiding was only 13 centimeter of water, she had an intermittent low flow pattern and dyssynergic voiding. Two-dimensional sonographic dynamic examination was performed in the patient. This is a dynamic film in the sagittal plane obtained with the endovaginal BK transducer 8848. Here, one can see the bladder, the urethra and the symphysis pubis. The sling can be seen to be bunched up and located beneath mid urethra, casting a shadow across the urethra. It can be clearly seen that the sling impinges on the urethra at rest, therefore it causes obstruction of the urethra at rest. On cough manoeuvre, the sling is seen to cause further obstruction of the urethra. The second patient is a 64 year old G3P3 with history of having undergone single incision sling surgery for SUI elsewhere. She came to us 18 months post surgery with history of one to two incontinence events per day, characterized as urgency incontinence and abnormal voiding with hesitancy and slow stream. On neurodynamic examination, the post-void residual was 70 ml. However, the detrusive pressure at peak flow was 32 cm of water. The patient voided with a contiguous configuration, low flow pattern with both the peak flow and mean flow at 5.8 ml per second. Functional assessment of the sling was performed on ultrasound. This is a two-dimensional film obtained in the sagittal plane with the endovaginal BK transducer 8848. Here you can see the bladder and urethra. The urethral lumen can be traced in its entirety from the urethrovascular junction until the external urethral meatus. At rest, the sling can be seen as an echo-dense structure lying beneath urethra, casting a shadow across the urethra. The sling can be seen to be curved and lying too close to the urethral lumen. It impinges on the urethral lumen and therefore causes obstruction of the urethra at rest. On Valsalva, the sling can be seen to cause further obstruction of the urethra. Many of these patients are Valsalva voiders. The Valsalva effort during voiding further compounds the obstruction. The third patient is a 64 year old Jeevan Prevan presenting with a history of TBT sling surgery done elsewhere two years ago. She reported worsening of urgency, frequency and nocturia following surgery. On neurodynamic testing, though her post-void residual was 350 ml, the intrusive pressure at peak flow was 11 centimeters of water. The patient voided with a peak flow of 15 ml per second in a contiguous configuration and normal pattern. The patient was however a Valsalva voider. On two-dimensional functional assessment with the transperineal BK transducer 8802, we can see at rest the bladder, the urethra, the symphysis pubis and the sling. At rest, the sling can be seen lying directly on the urethral lumen with no intervening tissue causing an indentation of the urethra. The sling thus causes an obstruction of the urethra at rest. On Valsalva, the sling can be seen to cause further obstruction of the urethra. Lastly, we have a 43 year old Jitu Pitu who had an uneventful follow-up for almost six years following trans-operator sling surgery performed for SUI. However, she started experiencing urgency and frequency, spontaneous loss of urine, incomplete bladder emptying and post-void dribble six months ago. Transperineal two-dimensional ultrasound was performed. Here you can see the bladder, the urethra, the symphysis pubis and the vagina. The mid-urethral sling is seen to be lying almost flat beneath proximal urethra. The midpoint of the sling is only 2.5 millimeter from the urethral lumen on cough. The sling is seen to bend and cause dynamic compression of the urethra. It, however, does not cause much obstruction of the urethra. However, on Valsalva maneuver, the sling can be seen to cause kinking of the proximal urethra, thereby causing obstruction of the urethra and the bladder neck. On further investigation, her urodynamic mituration study performed in 2006 revealed that she voided with Valsalva effort. The patient was advised physiotherapy to reduce Valsalva effort during voiding to prevent obstruction. In conclusion, two-dimensional functional assessment of the anterior pelvic compartment in patients with voiding dysfunction following sling surgery has several uses. It helps to diagnose the reasons for voiding dysfunction. It helps to understand the in vivo behavioral slings during dynamic events. It also aids in planning future treatment, especially in patients with inconclusive neurodynamic examination and variable symptoms. In all patients except the last one, the sling was transected with complete resolution of their symptoms. Thank you.

multi-compartment two-dimensional sonographic dynamic functional assessment

voiding dysfunction

sling surgery

urethral obstruction

bladder dysfunction