A sheathless technique can prevent ureteral trauma and allows to perform an intervention in case of tight ureteral orifice and in patients without preoperative stenting. Dr. Benjamin Pradere from Tours, France, evaluated perioperative outcomes in patients with renal stones who undergone fURS depending on the use of UAS. All the preoperative patients and stones characteristics were collected. The authors evaluated the operative time, the need for a basket, residual fragments rate at the end of the procedure, SFR at 3 months and the reintervention rate. The comparison between groups was performed using the Chi2 test and Fisher exact test for discrete variables and Mann-Whitney test for continuous variables.
It was a retrospective analysis of single-center experience. All patients with renal stones (n = 400) who undergone fURS in the clinic were included in the study. In 190 cases the UAS was used and in 194 patients a sheathless fURS was performed. The mean stone size was similar between groups (17.4 vs. 16.4 in UAS and sheathless group, respectively; p=0.43). Operative time was shorter in the UAS group (p=0.0001) with higher use of basket (80% vs. 64%; p<0.001). Residual fragments rate, as assessed by the surgeon at the end of surgery, was similar in both groups. More patients required a double-J at in UAS group (84% vs. 70%; p=0.001). The complication and reintervention rates were similar between groups as well as the SFR (75% vs. 74%, respectively; table 1).
The authors concluded that the sheathless technique did not negatively impact on SFR and reintervention rate, but required more time to achieve stone fragmentation. This technique is a good alternative to the standard approach and allows to reduce the costs of the procedure (less basket and postoperative drainage used). Also, Dr. Pradere pointed out that new high-power laser systems allowed to use a sheathless technique more commonly owing to better settings for stone dusting.
However, there are some pitfalls in this study that were highlighted during the discussion. First of all, the retrospective design doesn’t preclude a high risk of selection bias. In addition, the evaluation of SFR was done by means of US and X-ray. These methods have limited accuracy in small residual stones (< 5 mm). CT allows to determine stone volume and more precisely evaluate SFR. The most important consideration is the intrarenal pressure. In patients with low-compliant collecting system, the sheathless technique can be dangerous and associated with a high risk of sepsis. Although complication rates were similar in both groups, infectious complications were not specified. Therefore, during sheathless fURS it is crucial to constantly assess the irrigation and visualization and in case of absence of adequate outflow, a surgeon should consider using the UAS.
Presented by: Benjamin Pradere, MD, CHU Tours, Department of Urology, Tours, France
Written by: Kirill Shiranov, CDC “Zdorovie”, Rostov-on-Don, Twitter: @endourologist and Zhamshid Okhunov, MD, Twitter: @OkhunovZham, Department of Urology, University of California-Irvine at the 34th European Association of Urology (EAU 2019) #EAU19, conference in Barcelona, Spain from March 15-19, 2019.