The effectiveness and durability of ureteral tumor stent, the national taiwan university hospital experience

Tumor stent for chronic ureteral obstruction: Which are predictors of stent failure?

PURPOSE

To identify predictors of UROSOFT® tumor stent failure. According to the manufacturer, this reinforced ureteral stent has a maximal dwell time of 6 months. Nonetheless, stent failure may reduce this maximal dwell time.

METHODS

All patients undergoing first-time UROSOFT® tumor stent insertion in our institution between 2010 and 2018 were considered for this retrospective analysis. Primary endpoint was stent failure and defined as premature stent exchange or percutaneous nephrostomy insertion.

RESULTS

182 patients were available for analysis. Median age was 68 years. Causes for tumor stent placement were extrinsic ureteral obstruction in 144 patients (79 %) and intrinsic obstruction in 38 patients (21 %). Tumor stent failure free survival estimates at 1, 2, 3, 4 and 5 months were 89%, 83%, 76%, 65% and 52%, respectively. Patients with stent failure had significantly higher grade of hydronephrosis, higher urinary culture bacterial growth, higher serum WBC, higher CRP and lower eGFR at the time of re-intervention, compared to patients who underwent regular stent exchange. Of all baseline and perioperative parameters, we found bilateral insertion, intrinsic ureteral obstruction, and urinary tract infection (UTI) at time of tumor stent insertion to be significant and independent predictors of stent failure (all p < 0.05).

CONCLUSION

Despite a theoretical maximal dwell time of 6 months, around 50% of all cases are subject to premature stent failure. Predictors of stent failure are bilateral insertion, intrinsic ureteral obstruction, and UTI at the time of tumor stent insertion. Preoperative antibiotic therapy may impact on stent failure rate.

Clinical factors predicting ureteral stent failure in patients with external ureteral compression

Double-J stent (DJ) placement is usually the treatment of choice for relieving external compression of the ureter. However, in some cases DJ function may become impaired and a percutaneous nephrostomy (PCN) may be required. Previous studies have reported different predictive factors for choosing PCN or DJ insertion as the initial treatment. In this study, we analyzed the risk factors for DJ failure in patients with external ureteral compression. Our results showed that the patients with moderate and severe hydronephrosis (p-value = 0.0171 and 0.0249, respectively), preexisting pyuria (p-value = 0.0128), or lower ureter obstruction (p-value = 0.0305) were more prone to DJ laterality. Age was also an important predictor. Urologists should pay more attention to these patients and consider PCN as the initial treatment.

Comparison of single and tandem ureteral stenting for malignant ureteral obstruction: a prospective study of 104 patients

OBJECTIVES

The aim of this study was to compare single and tandem ureteral stenting in the management of malignant ureteral obstruction (MUO).

METHODS

Our hospital's institutional review board approved this prospective study. Between November 2014 and June 2017, single ureteral stenting was performed in 56 patients (94 renal units) and tandem ureteral stenting in 48 patients (63 renal units) for MUO. A comparative analysis of the technical success rate, patient survival, stent patency, and complications was performed.

RESULTS

Similar demographic data were observed in patients receiving either single or tandem ureteral stenting. The technical success rate was 93.6% (88/94) for single ureteral stenting and 95.2% (60/63) for tandem ureteral stenting. There was no difference in overall survival between patients receiving single or tandem ureteral stenting (p = 0.41), but the duration of stent patency in tandem ureteral stenting was significantly longer (p = 0.022). The mean patency time was 176.7 ± 21.3 days for single ureteral stenting, and 214.7 ± 21.0 days for tandem ureteral stenting. The complications of ureteral stenting were urinary tract infection (n = 18), lower urinary tract symptoms (n = 5), haematuria (n = 3), and stent migration (n = 1).

CONCLUSIONS

Tandem ureteral stenting is a safe and feasible treatment for MUO, and had better efficacy compared to single ureteral stenting.

KEY POINTS

• Ureteral stenting is an established treatment for the management of malignant ureteral obstruction (MUO) • Prospective single-centre study showed that tandem ureteral stenting is a safe and feasible treatment for MUO • Tandem ureteral stenting provides longer stent patency compared to single ureteral stenting in patient with MUO.