A prospective randomized single-blinded comparison of Ureteral Stent with distal loop design and its effect on early stent discomfort and QoL
K.S. Lim, Z.W Law, M.W.L.Chow, R.K Mangat, A.S.P. Sim, H.S.S. Ho
Department of Urology, Singapore General Hospital
Introduction & objectives
Ureteral stent discomfort causes significant morbidity. The PolarisTM loop ureteric stent has a unique soft distal loop, which reduces stent discomfort by minimizing stent material in the bladder. Early impact of ureteral stents on Quality of Life (QoL) within 1 week remains unclear. Patient-administered Ureteral Stent Symptoms Questionnaire (USSQ) was used to assess QoL post stent insertion.
This pilot single-blinded prospective randomized study compared the loop stent with pigtail stent.
Primary endpoint; determine the comfort profile of the loop stent using the Visual Analog Scale (VAS) and USSQ. Secondary endpoint; to investigate the presence of early stent discomfort and effects on QoL.
Materials & methods
40 adults requiring retrograde unilateral ureteral stent placements for 14-21 days were enrolled from April 2014 to July 2015 at a single institution. The USSQ was administered before placement (baseline), on Day 3, 7, and 14 to assess QoL. VAS was administered on Day 3, 7 and 14 to assess pain. Patients were randomized in 1:1 ratio to the loop and pigtail arm. Laser lithotripsy for single ureteric stone or benign stricture were selected. Stent for malignant conditions or previous ureteric stenting in the preceding year were excluded.
Results
60 patients were approached, 40 were enrolled. 2 from the pigtail group were excluded as they did not complete the USSQ and VAS. Mean age was 50 vs 52 years, gender distribution was 14 males & 6 female vs 14 males & 4 female in the loop and pigtail group. Mean duration of stent was 19 vs 25 days. Median USSQ scores were 82.0, 81.5 and 77.1 and 86.5, 91.0 and 81.2 on day 3, 7 and 14 in the loop and pigtail group. Median VAS scores were 2.9, 2.6 and 2.0 and 4.0, 2.6 and 2.9 on day 3, 7 and 14.
There were no significant differences between the USSQ scores. Median VAS on day 3 were lower in the loop group (2.9 vs 4.0, p=0.047). There was a significant reduction in pain from day 3 to 7 (0 vs -1, p=0.016) in the pigtail group. Multivariate analysis showed a downward time-trend in VAS scores (p=0.018) while higher baseline USSQ scores result in higher USSQ scores at the end of the study (p=0.018).
Conclusion
The loop stent offers a better QoL and pain profile although it lacks statistical significance. The loop stent achieves baseline pain by day 3. The pigtail stent only achieves pain comparable to loop stent by day 7. Within the 1st week of stent insertion, stent pain is most pronounced in both groups and improves with time. Peak impact of QoL in the loop group occurs early after stent insertion while the peak effect of QoL in the pigtail group occurs at day 7.