Hypothesis / aims of study
Most cases of voiding dysfunction from MUS insertion are due to over-tensioned slings. Some are mild and resolve with expectant management through intermittent catheterization. Some requests sling lysis and/or sling mobilization in the operating room, patients usually perceive them as another surgery, making them depressed, anxious, and dissatisfied. Tension-releasing suture (TRS) is a procedure applying an absorbable suture attached to one end of the anchoring tip allowing an easy relieve of over-tensioned sling in non-invasive manner. (1)
The aim of present study was to determine the clinical outcomes of adding tension releasing suture(TRS) appendage for manipulation of over-tensioned single-incision slings(SIS) as a means to relieve post-operative voiding dysfunction.
Study design, materials and methods
A retrospective case series study conducted in the in a tertiary referral center from January 2010 to July 2017 after gaining Institutional Review Board approval. The records of patients with urodynamic stress incontinence (USI) without needing concurrent procedures that underwent anti-incontinence surgery using MiniArc, Solyx, and Ajust with voiding dysfunction were collated and analyzed. The primary outcome measure was the recovery of normal post-void residual urine (PVR) after TRS manipulation. The secondary outcome measures were the pain intensity noted during manipulation (quantified through Visual Analog Scale), and the continence rate (assessed through 1. Objective cure- 1-hour pad test weight <2g and absence of USI; and 2. Subjective cure- index score of <1 on question #3 on UDI-6: “Urine leakage related to physical activity, coughing, or sneezing?”).
443 consecutive patients diagnosed with USI were offered with SIS surgery. Of these, 243 were treated using MiniArc, 145 using Solyx, and 55 using Ajust SIS insertion. On the 1st postoperative day, 370 (84%) patients had normal PVR, while 73 (17%) had high PVR. All 73 patients underwent introital ultrasonography. Forty-two (9.5%, 42/443) had over-tensioned slings and were managed with TRS manipulation, of which 23 had MiniArc, 5 had Ajust, and 14 had Solyx. The remaining 31 patients (7%, 7/443) who also had high PVR but no sling over-tension were managed with continuous intermittent catheterization. All patients in both groups regained normal PVR. No patient did self-catheterization after discharge.
The TRS manipulated group demonstrated an objective cure of 92.9% (39/42) and subjective cure of 91% (38/42) at one year follow up while the intermittent catheterization group had an objective and subjective cure rate of 97% (29/31). Postoperative hospital stay after TRS manipulated for Ajust SIS was significantly longer compared with the MiniArc SIS and Solyx. The manipulation of the TRS was mostly done once in the MiniArc and Solyx, while the Ajust needed further manipulations of the TRS. Pain experienced during TRS manipulation significantly increased with the Ajust system than Miniarc(p=0.018). There were 3 patients who had persistence of USI, 2 from MiniArc and 1 from Solyx. Objective cure rates at 1 year for each sling system were 91% for MiniArc, 93% for Solyx, and 100% for Ajust. Subjective cure was 87% for MiniArc, 93% for Solyx, and 100% for Ajust.
Comparison of pre-and post-operative urodynamics parameter (Qmax, MUCP, FUL, RU and Dmax) showed no significant difference among the three SIS systems. Subjective measurement on questionnaires (UDI-6, IIQ-7, and PISQ-12) showed significant improvement in all SIS kits postoperatively with no significant difference when compared to each other.
Interpretation of results
The TRS manipulation is considered effective if normal PVR is achieved without affecting continence. The present study shows 42 (9.5%) patients being managed with TRS manipulation from over-tensioned slings. All of these patients (100%) had normal PVR after manipulation. Continence was maintained at 1 year with objective and subjective cure rates of 93% and 90%, respectively. The persistence of USI in three (7%) patients could have resulted from too much traction on the TRS. The anchoring system on SIS should hook tightly to the tissue to provide stable tissue fixation. Modifications of the different SISs are mainly in the anchoring tip. The differences in the size, design, and placement in the muscle affect the traction force needed to move the sling during TRS manipulation. The Ajust system has the biggest anchoring tip size when placed inside the obturator internus muscle and given the system a highest pull-out force. More than one manipulation of the TRS is usually done because of this greater pull-out force. Pain was concurrently noted to be significantly greater compared with others.