Khalid M. et al., 2025: Clearance of 1-2 cm Renal Stones After Subjecting the Patients to Extracorporeal Shockwave Lithotripsy With and Without Double J Ureteral Stent.

Khalid M, Khan TS, Khan RA, Nawaz A, Javed H, Basit A.
Cureus. 2025 Oct 29;17(10):e95712. doi: 10.7759/cureus.95712

Abstract

Introduction: Renal stones measuring 1-2 cm are a common urological problem frequently managed with extracorporeal shock wave lithotripsy (ESWL). However, the role of pre-procedural double J (DJ) stenting in improving stone clearance and minimizing complications remains controversial. Some studies suggest that stenting facilitates fragment passage and prevents steinstrasse, whereas others report increased patient discomfort and urinary symptoms.

Objective: The objective of this study was to evaluate whether pre-ESWL DJ stenting improves stone clearance and reduces procedure-related complications in patients with 1-2 cm renal stones.

Hypothesis: Pre-procedural DJ stenting facilitates fragment clearance and lowers obstruction-related events without significantly increasing overall morbidity.

Materials and methods: This was a prospective comparative study conducted in Pakistan from January 2022 to December 2024. A total of 230 patients with single renal stones (1-2 cm) were randomized into Group A (ESWL with pre-procedural DJ stenting) (n = 115) and Group B (ESWL without stenting) (n = 115). In Group A, 6 Fr polyurethane DJ stents were inserted under local or spinal anesthesia 24-48 hours before ESWL. Procedures were performed using lithotripters operated using standardized parameters (energy range 12-21 kV, up to 3,000 shocks per session, and 60-90 shocks per minute. A maximum of three sessions was performed, spaced 10-14 days apart. All patients received standardized analgesic (diclofenac sodium 75 mg IM) and prophylactic antibiotic (ciprofloxacin 500 mg twice daily for three days) regimens. Stents were removed after achieving clearance or within four weeks. Stone clearance was evaluated at two and four weeks post procedure using ultrasonography and non-contrast CT (NCCT) when needed. Complete clearance was defined as the absence of fragments >4 mm. Complications, including hematuria, renal colic, infection, steinstrasse, and stent-related symptoms, were recorded. Data were analyzed using chi-square and t-tests; multivariate logistic regression identified independent predictors of stone clearance.

Results: Complete clearance was achieved in 95 (82.6%) stented versus 78 (67.8%) non-stented patients (p = 0.012). Residual stones >4 mm occurred in five (4.3%) stented and 15 (13.0%) non-stented patients (p = 0.021). Hematuria was more frequent in the stent group (n=20; 17.4%) than in the non-stent group (n=10; 8.7%) (p = 0.048). Stent-related symptoms were reported in 28 (24.3%) patients. Steinstrasse occurred more commonly in the non-stent group (n=15; 13.0%) than the stent group (n=4; 3.5%) (p = 0.011), while renal colic was seen in 14 (12.2%) non-stented versus six (5.2%) stented patients (p = 0.049). Multivariate analysis confirmed DJ stenting as an independent predictor of clearance (OR = 2.14; 95%CI: 1.22-3.74; p = 0.007).

Conclusion: Pre-ESWL DJ stenting is associated with higher stone clearance and fewer obstructive complications, such as steinstrasse and colic, but increases stent-related morbidity. Routine use in all patients is not justified; selective stenting should be considered for cases at higher risk of obstruction, including larger or impacted stones, solitary kidneys, or unfavorable anatomical configurations.

Comment Hans-Göran Tiselius

That DJ-stenting (internal stent) is beneficial to counteract complications of type steinstrasse is well recognized.

The reason is that the stent allows passage of urine despite fragment accumulation in the ureter.

How internal stents affect clearance of fragments has remained more controversial and although some studies have shown improved fragment clearance, others have shown that stents do not facilitate stone clearance.

The current study compared stone clearance in two randomized groups, A with stents and B without stents after SWL. Clearance in the two groups was 75% and 67%, respectively. This difference was statistically significant.

It is mentioned that the radiologists were blinded for which group the patients belonged to, I doubt this because the stents are visible on the images.

The conclusion put forward by the authors was that stenting should be selective and considered only for patients at risk:

Risk of obstruction

Impacted stones

Solitary kidneys

Unfavorable anatomy

Hans-Göran Tiselius