Sharma R et al, 2017: Can a brief period of double J stenting improve the outcome of extracorporeal shock wave lithotripsy for renal calculi sized 1 to 2 cm?
Sharma R, Choudhary A, Das RK, Basu S, Dey RK, Gupta R, Deb PP.
Department of Urology, SMS Medical College and Hospital, Jaipur, India.
Department of Urology, R G Kar Medical College and Hospital, Kolkata, India.
PURPOSE: Extracorporeal shock wave lithotripsy (ESWL) is an established modality for renal calculi. Its role for large stones is being questioned. A novel model of temporary double J (DJ) stenting followed by ESWL was devised and outcomes were assessed.
MATERIALS AND METHODS: The study included 95 patients with renal calculi sized 1 to 2 cm. Patients were randomized into 3 groups. Group 1 received ESWL only, whereas group 2 underwent stenting followed by ESWL. In group 3, a distinct model was applied in which the stent was kept for 1 week and then removed, followed by ESWL. Procedural details, analgesic requirements, and outcome were analyzed.
RESULTS: Eighty-eight patients (male, 47; female, 41) were available for analysis. The patients' mean age was 37.9±10.9 years. Stone profile was similar among groups. Group 3 received fewer shocks (mean, 3,155) than did group 1 (mean, 3,859; p=0.05) or group 2 (mean, 3,872; p=0.04). The fragmentation rate was similar in group 3 (96.7%) and groups 1 (81.5%, p=0.12) and 2 (87.1%, p=0.16). Overall clearance in group 3 was significantly improved (83.3%) compared with that in groups 1 (63.0%, p=0.02) and 2 (64.5%, p=0.02) and was maintained even in lower pole stones. The percentage successful outcome in groups 1, 2, and 3 was 66.7%, 64.5%, and 83.3%, respectively (p=0.21). The analgesic requirement in group 2 was higher than in the other groups (p=0.00). Group 2 patients also had more grade IIIa (2/3) and IIIB (1/2) complications.
CONCLUSIONS: Stenting adversely affects stone clearance and also makes the later course uncomfortable. Our model of brief stenting followed by ESWL provided better clearance, comfort, and a modest improvement in outcome with fewer sittings and steinstrasse in selected patients with large renal calculi.
Investig Clin Urol. 2017 Mar;58(2):103-108. doi: 10.4111/icu.2017.58.2.103. FREE ARTICLE
This article is an interesting report on the stent-use in association with SWL. It is assumed that the authors´ hypothesis for using a short (1 week) stenting period before SWL was to allow for a better clearance of fragments when the ureter is dilated. The three groups of patients included were:
1. SWL without stent
2. SWL with stent
3. SWL after one week of stenting. (Stent was removed before SWL).
The number of patients included in the study is relatively small, a fact that might hamper the definite conclusions. It is of note, however, that complete stone clearance was best in group 3. But why also stone disintegration was better in that group compared with that in groups 1 and 2 is not easily explained. One possibility is that the presence of a stent in group 2 comprises an obstacle to stone disintegration, but this explanation is not valid for group 1. Neither is it easy to explain why pre-stenting resulted in increased clearance of fragments from the lower calyces.
Despite a need of caution when the results from this study are interpreted, the suggested pre-treatment with stent might be advantageous.
Symptoms related to stent-use are well recognized. It needs to be mentioned that for the size of stones included in this study, stenting is normally not recommended.
A personal reflection: When stone clearance is poor, a short stenting period followed by SWL might be rewarding. For stones in the size range 15-20 mm (largest diameter) it is more doubtful to routinely add such a routine.