One day the authors were faced in the operating room with a 900mm3 lower pole renal stone using FANS. There was difficulty with reaching the stone by deflecting the sheath with the ureteroscope. We thus decided to position the tip of the ureteroscope in the lower pole, prior to advancing the sheath over the scope for suction – we found this made FANS access to the lower pole significantly easier.
Thus, the idea of the study was borne, with a description of two methods of deflecting FANS: the former “Ureteroscope Deflection Technique”, and the latter “Sheath Advancement Technique”. In our study, we conducted an in-depth in vitro analysis of maximal angles achieved with 6 flexible ureteroscopes with 3 different sizes of FANS, using the 2 methods.
It is with great excitement that in reporting the above, we hope to be able to standardize the terminology used globally for the future of FANS. This also presents considerations on the ideal combination of sheath-size and ureteroscope combination for deflection – findings applicable to the use of FANS in everyday clinical routine.
Written by: Alex Lua, MBBS, MRCS,1 Lynnette RL Tan, MBBS, MRCS,1 and Jia-Lun Kwok, MBBS, FRCS(Urol)(Glasg)1,2
- Department of Urology, Tan Tock Seng Hospital, Singapore, Singapore
- Progressive Endourological Association for Research and Leading Solutions (PEARLS), Paris, France