Key techniques for using FANS in ureteroscopy

In this video, Amy E. Krambeck, MD, discussed how the flexible and navigable suction (FANS) system influences intrarenal pressure, infection risk, operative efficiency, and surgeon experience during ureteroscopy.

Krambeck explained that active suction provided by FANS helps reduce intrarenal pressure by continuously removing irrigation fluid. However, when suction is turned off or obstructed, a closed system can form, leading to pressure spikes. Continuous suction is therefore critical to maintaining low intrarenal pressures and may also lower infection risk, although she noted that data confirming infection benefits are not yet available.

From her experience, the navigable suction sheath substantially reduces operative time and the need for auxiliary procedures, especially when managing larger stone burdens. She cautioned that because urologists are now tackling more complex stones with these devices, overall procedure times may not yet reflect the full efficiency gains. Dr. Krambeck emphasizes the need for comparative studies that match stone size to truly quantify time savings vs standard ureteral access sheaths.

Adopting FANS does come with a learning curve, as it requires more active hand coordination compared with conventional ureteroscopy. After several cases, however, most surgeons develop an efficient workflow. Krambeck offered several technical tips: maintain continuous suction with venting holes partially uncovered during lasering to prevent pressure buildup; fully cover the holes and toggle suction to extract fragments efficiently; and deflect the ureteroscope to improve fragment retrieval through vortex flow. She recommended using disposable ureteroscopes for FANS procedures due to increased instrument stress.

Finally, she advised surgeons to choose sheath size based on patient anatomy, noting that smaller (10/12 Fr) sheaths perform as well as larger ones while minimizing ureteral trauma. Overall, FANS represents a promising evolution in ureteroscopy, enhancing efficiency and safety when used with careful attention to pressure dynamics.