Study design, materials and methods
Following IRB approval, participants in E-SISTEr at one center who returned for a mid-term office evaluation in 2010 were further re-evaluated for longer term follow-up. This follow-up included office visits and a structured telephone interview, conducted by a third party investigator not involved in patient care, for those not seen in the last 2 years. Both groups received same validated questionnaires, including Urogenital Distress Inventory-Short Form (UDI-6), Incontinence Impact Questionnaire-Short Form (IIQ-7), and visual analog quality of life score (QoL). Failure was measured by a Kaplan-Meier curve using time to reoperation for SUI.
Of 29 eligible patients (B=14, S=15), 21 had long-term information (B=11, S=10). Of the 8 lost to follow-up, 1 was deceased and 7 were unreachable by phone. Median follow-up was 15.1 years (range: 11.2-16.0). UDI-6 Q#3 score was lower for those followed up by phone (n=13, mean=0.3 ± 0.6) compared to those seen in clinics (n=8, mean=1.3 ± 1.1) (p=0.0208).
UDI 6 questionnaire showed slightly increased urge incontinence (Q2) in the sling group, slightly increased stress incontinence (Q3) in Burch group, and minimal voiding difficulties in both groups (Q5). The Burch group had slightly higher quality of life and IIQ-7 scores. None of the above stated differences reached statistical significance. All of our patients were not sexually active by choice, and none had complaints of sexual dysfunction or dyspareunia. The average pads per day was 1.4, with 9 women requiring 0 pads and 4 women wearing 1 pad.
Reoperation for SUI was reported in 3 patients (B=2, S=1), with fascial sling placement (B=1) or injectable agents (B=1, S=1). The overall Kaplan-Meier 15-year reoperation free survival rate was 85.2% (95% CI: 60.8% - 95%) [Burch: 80.8% (95% CI: 42.3% - 94.9%), Sling: 90% (95% CI: 47.3% - 98.5%)].
Interpretation of results
This study offers a glimpse of what happened in very long-term follow-up of a well characterized group of women entered in the SISTEr study (2002 – 2004) at one tertiary care center. Both groups had sustained improvement over time in questionnaire scores (UDI-6 Q3 average <1) and quality of life measures relating to SUI. Though not statistically significant, the sling procedure had lower UDI-6 Q3 stress incontinence scores and higher UDI-6 Q2 urge incontinence scores, similar to previously reported follow-up of SISTEr trial patients [1,2].
The statistically significant increase in UDI-6 Q3 stress incontinence scores in the clinic FU group vs. phone FU group may be explained by the fact that women who are doing well chose not to return to clinic for examination. Alternatively, patients not returning to clinic could be older or have farther distance to travel, but in our cohort, we found phone FU patients were not older or living farther away.
Despite our sample size, our patients were well characterized from the original SISTEr trial. [1,2] The trial was rigorously designed, randomized, and had strict inclusion and exclusion criteria. Participants had predominant stress incontinence with no voiding obstruction proven by an extensive preoperative evaluation: leakage by standardized stress test at bladder volume of 300 mL, urethral hypermobility, voiding diary, urodynamic evaluation, and validated questionnaires [1,2]. At baseline, the women had >3 incontinence episodes per day, high total UDI-6/IIQ-7 scores, and high SUI scores that improved significantly at 2 and 5 years [1,2]. At very long-term follow-up in our cohort, pad use and scores were still low.
Our reoperation rates at 18% for Burch and 10% for fascial sling are comparable to those published in literature. In a population based analysis of health care claims data on anti-incontinence procedures in the United States, the 9 year cumulative study incidence of reoperation was 11% for Burch and 13% for urethral slings (mid urethral and pubovaginal slings) .