Application of resonance metallic stents for benign and malignant ureteral obstruction: long-term follow-up
Lin-Nei Hsu1*, Hung-Jen Wang1*, Hao-Lun Luo1, Yuao-Tso Cheng1, Chien-Hsu Chen1, Tze-Yu Lee2, and Po-Hui Chiang1
1 Department of Urology, Chang Gung Memorial Hospital – Kaohsiung medical center, Chang Gung University College of Medicine, Kaohsiung, Taiwan
2 Department of Radiology, Chang Gung Memorial Hospital – Kaohsiung medical center, Chang Gung University College of Medicine, Kaohsiung, Taiwan
* Dr. Hsu and Wang contribute equally to this manuscript and serve as co-first authors.
Purpose: To evaluate the outcomes of the metallic Resonance® ureteral stent and clarify the risk factors that lead to stent failure. In the present study, we present 5 years of our experiences with the use of a Resonance stent for malignant and benign ureteral obstruction.
Materials and Methods: We retrospectively identified and analyzed the records of all patients in whom Resonance® Metallic Ureteral Stent was placed between early 2009 and late 2014 in our hospital. We performed a descriptive analysis of key outcomes, including the failure and stenting duration, defined as the time from initial stent placement to last stent failure or patient death.
Results: A total of 52 metallic stents were placed in 36 patients, including 44 (84.6%) with malignant and 8 (15.4%) with a benign etiology. Maximum follow-up was 58 months (mean 14.7, median 8.5, IQR 14.9). Stent failure occurred in 10 patients (19.2%). The re-occlusion rate was significantly higher in the subgroup with urinary bladder invasion malignancy during Resonance stent insertion (p= 0.035). Patients who had had previous radiation therapy had a lower patency rate in comparison with non-radiation patients (p= 0.001), especially in patients with Resonance stent placement more than one year (p= 0.018). And the 50% patency rate with 52 stents was 10 months.
Conclusions: The Resonance metallic stent could be safely applied for those malignant or benign ureteral obstructions. For malignant ureteral obstruction, previous radiation therapy is a risk factor for stent failure, especially for those with long-term stent placement. We also suggested revision of Resonance metallic stent every one year to keep stent patency and prevent stent complications.