Placement of retrievable self-expandable metallic stents with barbs into patients with obstructive prostate cancer

Efficacy and tolerability of metallic stent in patients with malignant prostatic obstruction secondary to prostatic cancer

OBJECTIVE

To evaluate the efficacy and tolerability of a self-expandable covered metallic stent in patients with malignant prostatic obstruction secondary to prostate cancer (PC).

METHODS

We reviewed 22 cases of insertion of self-expandable covered metallic stents with barbs. Data were collected about PC status. Uroflowmetry variables, residual urine volume, International Prostate Symptom Score (IPSS), quality of life (QOL), and duration from stent insertion to removal were surveyed. These clinical parameters were compared before and after stent insertion.

RESULTS

The patients with PC showed a mean age of 75.5 ± 6.5 years and mean 5.1 ± 1.9 Charlson comorbidity index. The average flow rate (2.4 ± 1.9 vs 5.9 ± 2.4 mL/s, P = .005), peak flow rate (6.9 ± 6.2 vs 14.1 ± 5.5 mL/s, P = .003), flow time (54.6 ± 29.1 vs 23.6 ± 13.7 s, P = .002), residual urine volume (178.7 ± 195.5 vs 7.0 ± 7.1 mL, P = .004), IPSS (26.2 ± 8.1 vs 8.0 ± 6.5 points, P = .001), and QOL (4.7 ± 1.3 vs 2.4 ± 2.1 points, P = .030) improved between before and after stent insertion, respectively. Pain was the most common complication, but 60% of the patients were managed without any intervention. There were hematuria, urinary retention, urinary frequency, obstruction, and urinary incontinence. However, there was no urinary tract infection due to the stent. The median time to stent removal was 5.7 months.

CONCLUSIONS

The stent was maintained for about 6 months with improved objective and subjective outcomes. The patients with PC, who had a poor comorbidity index and advanced PC status showed a tolerable maintenance period. Self-expandable covered metallic stents can be used for PC patients with a short life expectancy and unsuitability for general anesthesia.

Sirolimus-eluting Biodegradable Poly-l-Lactic Acid Stent to Suppress Granulation Tissue Formation in the Rat Urethra

Purpose To investigate the use of sirolimus-eluting biodegradable stents (SEBSs) to suppress granulation tissue formation after stent placement in a rat urethral model. Materials and Methods All experiments were approved by the animal research committee. A total of 36 male Sprague-Dawley rats were randomized into three equal groups after biodegradable stent placement. Group A received control biodegradable stents. Groups B and C received stents coated with 90 µg/cm² and 450 µg/cm² sirolimus, respectively. Six rats in each group were sacrificed after 4 weeks; the remaining rats were sacrificed after 12 weeks. The therapeutic effectiveness of SEBSs was assessed by comparing the results of retrograde urethrography and histologic examination. Analysis of variance with post hoc comparisons was used to evaluate statistical differences. Results SEBS placement was technically successful in all rats. Urethrographic and histologic examinations revealed significantly less granulation tissue formation at both time points in the rats receiving SEBSs (groups B and C) compared with those that received control stents (group A) (P < .05 for all). There were no significant differences in urethrographic and histologic findings between groups B and C (P > .05 for all). However, the mean number of epithelial layers in group B was higher than that in group C at 4 weeks after stent placement (P < .001). Apoptosis increased in group C compared with groups A and B (P < .05 for all). Conclusion The use of SEBSs suppressed granulation tissue formation secondary to stent placement in a rat urethral model; local therapy with SEBSs may be used to decrease stent-related granulation tissue formation. ^© RSNA, 2017.