Status study of clinical application of ureteral access sheath in urology: a narrative review.

As one of the effective minimally invasive methods for upper urinary tract stone treatment, ureteroscopic lithotripsy has gradually become the mainstream surgical approach. The routine use of ureteral access sheaths (UAS) during ureteroscopic lithotripsy has plenty of advantages. Although many concerns have emerged in the clinical practice of the UAS, the clinically improved devices have addressed these issues. This article reviews the advantages, existing issues, and current improvements of UAS in clinical practice, aiming to provide references for better clinical application and further improvements of UAS. We searched in PubMed database using the terms: "ureteral access sheath", "ureteroscopic lithotripsy" or "flexible ureteroscope". Articles were independently evaluated for inclusion based on predetermined criteria. The routine use of UAS during ureteroscopic lithotripsy facilitates the entry and exit of the ureteroscope, improves intraoperative visibility, and reduces postoperative complications. However, concerns over ureteral wall injury, difficulty in controlling renal pelvic pressure, lack of reduction in operation time, failure to increase stone free rates, and controversies regarding the ratios of endoscope-sheath diameter have limited the clinical application of UAS. The emergence of clinically improved devices such as intelligent pressure controlled, tip bendable, and rigid ureteroscope aided UAS has addressed these issues, laying a foundation for their further clinical application. The clinical improvement of the UAS can serve as a bridge for the widespread usage of the ureteroscopic lithotripsy. In the future, we anticipate more innovative advancements in UAS, making their clinical use even more practical and convenient.