“…The access sheath is only introduced if the ureter allows it (13); Otherwise, it is advisable to place a double-J catheter and postpone the surgery or perform flexible ureteroscopy using a working wire. However, in patients for whom the decision is made to perform the procedure without UAS after failed insertion attempts, there is a higher likelihood of encountering complications and facing challenges in achieving a stone-free status compared to cases where the procedure was initially planned to be performed without a sheath (18).…”