Grooved vs smooth ureteric stent before extracorporeal shockwave lithotripsy: Single-blind randomised clinical trial

Objective: No study compared the grooved stent to the widely used standard smooth (non-grooved) stent in humans. We compared stone clearance, complications, and patient tolerance of the grooved stent vs standard JJ stent. Patients and Methods: Single-blinded randomised trial among patients planned for pre-extracorporeal shockwave lithotripsy (ESWL) stenting. Adult patients with unilateral ureteric/renal stones planned for ESWL were randomly assigned to receive (Percuflex) smooth ureteric stent or (Visiostar) grooved lithotripsy stent and blinded to the stent type. We collected and compared the baseline data and outcomes (stone-free rate, complications, and stent-related symptoms) of both patient groups. Results: A total of 96 adults were included (48 per arm). There were no significant differences between the groups at baseline in terms of demographics, body mass index, comorbidities, renal function, number of ESWL sessions, and stone characteristics, including pre-ESWL stone volume (mean [SD] smooth 310.2 [301.6] vs grooved 270.7 [278.6] mm3, P = 0.5). Stone clearance was statistically insignificant between the groups, although clinically relevant (smooth stent 70.8% vs grooved stent 81.2%, P = 0.2). Grooved-stent patients reported comparable urinary symptoms score (P = 0.05) and operative complications (P = 0.6), but significantly more urinary tract infections (UTIs) not requiring hospitalisation (P = 0.003). Conclusions: Although statistically insignificant, the grooved stent exhibited higher stone clearance compared to the smooth stent, with similar complication rates excpet that patients with grooved stents reported more UTIs. A re-visit to the size of the outer diameter of the grooved stent could enhance its stone clearance properties, and further development of its coating material could lead to better patient satisfaction.