Can negative ureteroscopy be predicted in ureteral stone treatment?

Abstract

Introduction: We aimed to evaluate factors predictive of negative ureteroscopy (URS) in ureteral stones.
 Methods: Patients who underwent URS between January 2007 and June 2018 were included in the study. Patients were divided into two groups; group 1: positive URS (841 patients) and group 2: negative URS (75 patients). These two groups were compared in terms of demographic data, stone characteristics, and postoperative outcomes.
 Results: The mean age of the study patients was 44.5±15.1 years. The absence of collecting system dilatation due to the present stone was found to be a significant predictive factor for negative URS in univariate analysis, but there was no significant difference in multivariate analysis. In the multivariate analysis, low body mass index (BMI), no history of stone surgery, stone located in the distal ureter, small stone area, longer time between the last imaging procedure and URS, and medical expulsive therapy (MET) application were statistically significant in predicting negative URS.
 Conclusions: In this study, the parameters that significantly predicted negative URS were found to be low BMI, no history of stone surgery, distal localization of the stone, small stone area, longer time between the last imaging procedure and URS, and MET applied for the current stone. These parameters should be considered to avoid negative URS and patients should be informed of the possibility of negative URS prior to operation.

Long surgical waiting list times are associated with an increased rate of negative ureteroscopies

“…Different hospitals will have different interpretations of this, but considering that the natural history of conservatively managed ureteral stones shows spontaneous passage within 4 weeks on average 17 and that spontaneous passage is also measured at 4 weeks in clinical trials 18 , a cut-off of 2 months (>60 days) may be considered prudent. In our study, we observed that the rate of NURS in the first 2 months was similar to rates previously reported in the literature [1][2][3][4][5] , while patients operated on beyond 2 months had an exceedingly high NURS rate. Although there is no clear explanation as to why a long WLT may increase the NURS rate, one possible explanation is that radiolucent stones, likely to be composed at least partially of uric acid, may decrease in size due to urinary pH changes and pass spontaneously.…”

“…NURS rates reported in the literature range from 3.8% to 13% [1][2][3][4][5] . Many authors have sought to determine the risk factors associated with NURS in order to avoid unnecessary surgical interventions.…”

“…The incidence of NURS has been reported in some series to be between 3.8% and 13% [1][2][3][4][5] . These series have reported certain risk factors to be associated with NURS, including female gender, small stone size, low stone density, and distal location.…”

This stone (may?) too shall pass

“…2 This is possib�y �ue to the exc�usion of stones >10 mm in si�e �n� the �onge� su�gic�� w�it times in this se�ies. 3 The fin�ings of this stu�y ��e consistent with p�evious �epo�ts, which h�ve ��so foun� sm���e� stone si�e �n� ���io��ucent stones to be �ssoci�te� with highe� ��tes of neg�tive URS. 4,5 A��ition�� f�cto�s, inc�u�ing fem��e gen�e� �n� stone �oc�tion in the �ist�� u�ete�, h�ve ��so p�evious�y been foun� to be p�e�ictive of neg�tive URS.…”

“…4,5 A��ition�� f�cto�s, inc�u�ing fem��e gen�e� �n� stone �oc�tion in the �ist�� u�ete�, h�ve ��so p�evious�y been foun� to be p�e�ictive of neg�tive URS. 3,5 The �utho�s shou�� be commen�e� on pub�ishing the fi�st �epo�t specific���y ex�mining the effect of su�gic�� w�it times on the inci�ence of neg�tive URS. Whi�e URS is � ve�y s�fe �n� common�y pe�fo�me� p�oce�u�e, it is not without �isks; � g�ob�� stu�y pe�fo�me� by the C�inic�� Rese��ch Office of the En�ou�o�ogic�� Society (CROES) h�s p�evious�y �emonst��te� �n ove���� 3.5% comp�ic�tion ��te with URS.…”