Allium stent for the treatment of a malignant ureteral stenosis: A paradigmatic case

Allium® ureteral stent, a new player in the treatment of ureteral stenosis: a prospective cohort study

INTRODUCTION AND OBJECTIVES

Ureteral stricture is a chronic condition that can result in the obstruction of urinary drainage from the affected renal unit, leading to loss of renal function. Treatment methods can be categorized into two main headings: endourological and reconstructive procedures. We aimed to investigate the efficacy and safety of the self-expandable Allium® ureteral stent, which has been used in the minimally invasive treatment of ureteral stenosis in recent years.

MATERIALS AND METHODS

Twenty patients who were applied Allium® ureteral stent between 2017 and 2021 included in the study. The demographic and clinical characteristics of the patients, the details of the treatments applied to the patients, the perioperative and postoperative complications, the treatments applied for the complications and the findings in the follow-up were recorded and evaluated prospectively.

RESULTS

Etiology included urolithiasis in 16 patients (80%), malignancy in 3 patients (15%), and a previous gynecological operation in 1 patient (5%). Stent obstruction was found to be the most common complication in 3 patients (15%). Stent migration was the second most common complication in 2 patients (10%). Our follow-up continues with 15 patients without stent-related complications and stent obstruction. The mean follow-up period was 28 ± 15.7 months.

CONCLUSIONS

Allium ureteral stent is an effective and reliable method in the minimally invasive treatment of ureteral stricture with complications seen at acceptable rates and ease of treatment in the management of complications.

The Resonance and the Allium ureteral stents in the treatment of non-malignant refractory ureterostenosis

Background

Refractory non-malignant ureterostenosis is challenging to treat. The experience to treat the stenosis primarily cause by retroperitoneal fibrosis with the Resonance and Allium metallic stent is still limited. We aim to evaluate the efficacy and safety of these two stents and provide alternative treatment options.

Methods

A retrospective study was conducted for patients with non-malignant ureterostenosis and treated with the Resonance and Allium stents from March 2011 to September 2020 in our department. The efficacy was evaluated by the change of serum creatinine, glomerular filtration rate (GFR), the proportion of GFR of the affected side and hydronephrosis grade. The safety was evaluated by postoperative presence of moderate or severe overactive bladder (OAB), recurrent urinary infection, pain, stent displacement, encrustation and re-obstruction.

Results

33 patients were eligible for the study, including 18 cases treated by the Resonance stents and 15 patients treated by the Allium stents. The patients of two groups had similar age and gender proportion. The cause of ureterostenosis was mainly retroperitoneal fibrosis in both groups but the Resonance group had more idiopathic cases. Follow-up time was significantly longer in the Resonance group than the Allium group (36.2 ± 24.0 vs 9.4 ± 5.0 months, p < 0.001). Both groups showed improvement or maintenance of serum creatinine level, GFR, the GFR proportion of the affected side and hydronephrosis grade after treatment. The Resonance group presented significant higher incidence of moderate or severe OAB, recurrent urinary infection and pain, while the Allium group showed significant more cases of re-obstruction.

Conclusion

Both the Resonance and Allium stent can relieve the non-malignant refractory ureterostenosis effectively. The Resonance stent may cause more irritable symptoms while the Allium stent may have a higher rate of re-obstruction. The long term efficacy and safety of the Allium stent in treating non-malignant refractory ureterostenosis requires further study.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12894-021-00815-6.