Minimally invasive kidney stone surgery continues to push the envelope for surgical innovation in urology. At Chicago’s AUA 2023 Annual Meeting on Friday afternoon, April 28, the semi-live surgery plenary session featured new devices and surgical techniques in action.

Ureteroscopy: LithoVue Elite and Ho:YAG Laser With Moses Pulse Modulation

Dr Ben Chew from the University of British Columbia presented a case using the new LithoVue Elite (Boston Scientific, Marlborough, Massachusetts), the second-generation disposable ureteroscope with the highly anticipated feature of live intraoperative pressure monitoring. He also featured different dusting settings on the Moses laser to obtain maximal efficiency. By combining the two technologies, Dr Chew demonstrated how a patient with a large renal stone and a history of sepsis who was not a candidate for percutaneous surgery could be safely treated using ureteroscopy and laser lithotripsy. Key points included keeping intrarenal pressures low and using the distance setting on the Moses laser to avoid burn-back on the laser fiber while dusting. The new pressure-measurement capability of the LithoVue Elite may be an enabling technology that encourages urologists to avoid over-pressurizing the collecting system during ureteroscopy, thereby reducing the risk of sepsis. If trial data continue to be supportive, it could be a major clinical advancement for safer surgical stone care in ureteroscopy.

Mini Percutaneous Nephrolithotomy With Thulium Fiber Laser

Dr Thomas Chi from the University of California, San Francisco presented a case using pure ultrasound-guided access for mini-percutaneous nephrolithotomy (PCNL) and lithotripsy using a thulium laser. This case featured the Ultraxx balloon and dilation sheath (Cook Medical, Bloomington, Indiana), a clear mini-PCNL sheath that permits visualization of the dilated tract, facilitating accurate adjusting of the depth of dilation upon insertion of the nephroscope. The fine dusting properties of the Cook Fiber Dust thulium laser demonstrated in this case allowed for precise treatment of an embedded stone at the ureteropelvic junction with minimal unintentional damage to the urothelium. The thulium laser’s coagulative properties were also showcased during an infundibulotomy procedure. Key points included (1) encouraging urologists to adopt ultrasound for PCNL given its easier learning curve and decreased radiation exposure compared to fluoroscopy, (2) demonstrating that lithotomy position facilitates combined antegrade and retrograde endoscopy, particularly useful with abnormal anatomy, and (3) that the thulium laser is adept for dusting stones and especially good with infundibulotomy procedures.

LithoVue Elite Clinical Experience

Dr Naeem Bojani from the University of Montreal presented several surgeries showcasing the LithoVue Elite. The first case demonstrated how intrarenal pressure changes during different parts of the case, rising above the threshold of 40 mm Hg when scoping a calyx and with more aggressive irrigation during lithotripsy. The second case provided a great example of how intrarenal pressures can be affected by outflow drainage. In this case, a tight ureter and ureteropelvic junction impaired the outflow even with an 11/13F ureteral access sheath in place, thus leading to much higher intrarenal pressures compared to the first case. The third case demonstrated how keeping intrarenal pressures low with intermittent aspiration can help mitigate infection risk for a patient with a history of sepsis from ureteroscopy. As new data emerges, we anticipate that the importance of understanding intrarenal pressure during stone surgery will become more and more apparent.

Ureteroscopy and Ho:YAG Laser Lithotripsy With Use of CVAC to Aspirate Fragments

Dr Stuart Wolf from the University of Texas-Austin presented the use of the CVAC sheath (Calyxo, Pleasanton, California), a device designed to facilitate active suctioning of stone fragments after lithotripsy. This device, new to the market, is designed to improve stone-free rates after ureteroscopy and laser lithotripsy. Once the ureteroscopy portion of the procedure is completed, CVAC is inserted into the kidney under fluoroscopic guidance and used to suction stone pieces, allowing the surgeon to forego the laborious basketing process. One optimizing strategy highlighted with this device involved having the patient in Trendelenburg position to allow fragments to collect in the upper pole, thus facilitating direct access with the CVAC sheath. If stones collect in multiple calyxes, the sheath can be directed with the ureteroscope to those calyces for suction. This enabling technology may greatly enhance stone-free rates after ureteroscopy and allow for greater success in treating larger stones in a minimally invasive fashion.

Radiation Reduction: The Life You Save May Be Your Own!

Dr Duane Baldwin from Loma Linda University presented strategies to reduce radiation in stone surgery. Highlights of his talk included reviewing the “as low as reasonably achievable” principle and how to optimize C-arm settings to reduce radiation when it is used. Using the low dose and pulse settings are easy ways to cut radiation exposure to surgeons, patients, and staff with the push of 2 buttons on any fluoroscopy unit. Also demonstrated was the use of a laser guide to direct needle trajectory during percutaneous renal access to avoid using x-rays and the use of endoscopic combined intrarenal surgery techniques to direct percutaneous access. The key point was to appreciate the cumulative harms of radiation to patients and surgeons. Employing techniques to minimize radiation during these cases can have long-term positive health benefits.