Stent diameter and stent-related symptoms, does size matter? A systematic review and meta-analysis

The ureteral insertion of a silicone tube was first performed in 1967. A validated ureteral stent symptom questionnaire (USSQ) is used for an objective assessment of patient-reported stent-related symptoms. As the impact of stent diameter on the incidence of stent-related symptoms is unclear, we aimed to perform a systematic review and meta-analysis comparing USSQ reported outcomes when using a 6 Fr diameter ureteric stent, versus smaller diameter stents (4.7-5 Fr) when inserted for ureteric stones. All randomized control trials and comparative studies of 6 Fr versus 4.7-5 Fr ureteric stents were reviewed. The USSQ outcomes were considered as the primary outcome measures while stent migration was considered as a secondary outcome measure. A total of 61 articles were identified of which four studies met the eligibility criteria. There was a statistically significant association between the use of wider (6 Fr) diameter stents and the incidence of urinary symptoms as measured by the urinary index score. Larger stent diameters were associated with a statistically significant increase in the pain index score. There was no statistically significant difference in the scores between the compared stent diameters with regard to work performance score, general health index score, additional problems index score, and stent migration. There were insufficient reported outcomes to perform a meta-analysis of sexual matters index score. Our meta-analysis shows that using smaller diameter ureteric stents is associated with reduced urinary symptoms and patient-reported pain. Other USSQ parameter outcomes are statistically similar in the 6 Fr ureteric stent cohort versus the 4.7-5 Fr ureteric stent cohort. Our meta-analysis was limited due to the limited number of studies and gross heterogeneity of reporting parameters in various studies. We hope a large-scale homogeneous randomized control trial will further shed more insight into the stent symptoms response to stent diameter.