A magnetic hydrogel for the efficient retrieval of kidney stone fragments during ureteroscopy

Abstract

Surgical management of stone disease aims for complete clearance, yet only 60–75% of ureteroscopic laser lithotripsy treatments achieve complete stone-free status. Up to 30% patients with residual fragments < 2 mm in size experience stone-related complications. We demonstrate a method of stone fragment retrieval in which fragments are coated with a magnetic hydrogel and retrieved en masse with a magnetic guidewire. The magnetic hydrogel facilitated robust in vitro capture of stone fragments up to 4 mm in size across a wide range of stone compositions. The components exhibited no cytotoxicity in cell culture and only superficial effects on the urothelium in ex vivo human urothelium and in vivo mouse bladders. Furthermore, the hydrogel demonstrated antimicrobial activity against common uropathogens on par with that of common antibiotics. By enabling the efficient retrieval of kidney stone fragments, our method could lead to improved stone-free rates and patient outcomes.

Physical Techniques to Remove Residual Stone Fragments in the Urinary System

“…In addition, this study also conducted in vitro tests by cultivating urethral inflammatory cells, and found that hydrogel components had no cytotoxicity in cell culture, and had certain antibacterial ability, and had only superficial effects on human urothelium in vitro and mouse bladder in vivo. This effective method of extracting kidney stone fragments can improve stone rate and patient prognosis [25]. At present, most methods of active removal of RF are to use a wire basket, introduce the encrusted stone through a ureteroscope, and remove it from the body.…”

“…Methods are now emerging that focus on adhering RF to autologous blood clots or biopolymers to facilitate basket extraction. At present, the use of a magnetic extraction method has great prospects and greatly improves the stone expulsion rate, but further improvement is still needed, for example, studies have found that the use of catheter-based magnetic tools to magnetize kidney stones and recover them is limited by low magnetic strength [25].…”