Ureteral stent extraction strings in children: Stratifying the risk of post operative urinary tract infection

Introduction: Ureteral stents facilitate recovery and avoid external drains in pediatric ureteral reconstruction. Extraction strings avoid the need for a secondary cystoscopy and anesthetic. Due to concerns regarding febrile UTIs in children with extraction strings, we retrospectively assessed the relative risk of UTI in children with extraction strings. Objective: Our hypothesis was that stents with extraction strings do not increase the risk of UTI after pediatric ureteral reconstruction. Methods: Records of all children undergoing pyeloplasty and ureteroureterostomy (UU) from 2014 to 2021 were reviewed. The incidences of UTI, fever, and hospitalization were recorded. Results: 245 patients mean age 6.4 years (163M:82F) underwent pyeloplasty (n = 221) or UU (n = 24). 42% (n = 103) received prophylaxis. Of these, 15% developed UTI versus 5% of those not receiving prophylaxis (p < 0.05). 42 females had prior history of UTI, compared to 20 males (p < 0.05). 49 patients had an extraction string. Stents with extraction strings were removed on average 0.6 months post-op while others underwent cystoscopic removal on average 1.26 months post-op (p < 0.05). 9 (18.4%) required hospitalization for febrile UTI while the stent with extraction string was in place, while only 13 (6.6%) of those without extraction string did (p < 0.02). Of the 9 children with a febrile UTI in the extraction string group, 6 had history of prior UTI (46.1%), compared to only 3 (8.3%) without a prior UTI (p < 0.05). With no prior UTI, there was no difference in UTI risk between those with (3, 8.3%) and without (8, 6.4%) extraction string (p = 0.71). Females with prior UTI and extraction string were more likely to develop UTI than those with prior UTI and no extraction string (p = 0.01). There were not enough males with history of UTI to analyze alone. There were 5 (10%) stent dislodgements in the extraction string group, 2 required further intervention with cystoscopy or percutaneous drainage. Discussion: Extraction strings provide the assurance of drainage while avoiding the need for a second general anesthetic procedure. There is not an increased risk of UTI with extraction string in those without prior history of UTI, but we no longer routinely leave extraction strings if there is history of UTI. Conclusion: Children, particularly females, with prior history of UTI have a significantly increased risk of febrile UTIs associated with the use of extraction strings. Prophylaxis does not seem to reduce this risk. Patients with no prior UTI had no higher risk of UTI with extraction string use for pyeloplasty or UU.[Formula