Malignant Ureteral Obstruction: Functional Duration of Metallic versus Polymeric Ureteral Stents

Abstract

BackgroundUreteral obstruction caused by extrinsic compression is often associated with intra-abdominal cancers. Internal drainage with ureteral stents is typically the first-line therapy to relieve such obstructions. Novel designs of ureteral stents made of different materials have been invented to achieve better drainage. In this study, we described the functional outcomes of a Resonance metallic ureteral stent (Cook Medical, Bloomington, Indiana, USA) in patients with malignant ureteral obstruction and compare the functional duration of Resonance stents with regular polymeric stents in the same cohort.MethodsCancer patients who received polymeric stents and subsequent Resonance stents for ureteral obstruction between July 2009 and November 2012 were included in a chart review. Stent failure was detected by clinical symptoms, imaging studies, and renal function tests. The functional durations of each stent were calculated, and possible factors affecting stent patency were investigated.ResultsA total of 50 stents were successfully inserted into 50 ureteral units in 42 patients with malignant ureteral obstruction. There were 7 antegrade stents and 43 retrograde stents. There were no major complications. Stent-related symptoms were similar in both kinds of stents. After polymeric stents were replaced with Resonance metallic stents, hydronephrosis subsided or remained stable in 90% (45/50) of the ureteral units. Serum creatinine decreased or remained stable in 90% (38/42) of these patients. The Resonance stent exhibited a mean increase in functional duration of 4 months compared with the polymeric stents (p<0.0001), and 50% (25/50) of the Resonance stents exhibited a significant increase in functional duration (more than 3 months). Pre-operative serum creatinine < 2 was associated with a substantial increase in stent duration.ConclusionsResonance stents are effective and safe in relieving malignant ureteral obstructions after polymeric stents failure. Resonance stents can provide a longer functional duration than polymeric stents and should be offered as an option for internal drainage.

Ureteral JJ Stent � Which One is Better?

“…In conclusion, the Resonance stent was more effective in cases with severe obstruction. Only minor complications were reported (dysuria, fever, urinary frequency, flank pain, and hematuria), similar to those seen with the polymeric stents [31].…”

Treatment outcomes of ureteral stenting for malignant extrinsic ureteral obstruction: a comparison between polymeric and metallic stents

“…As polymeric stents are fragile against extrinsic MUO, they often require replacement. Therefore, several studies have evaluated the applicability of metallic stents, rather than polymeric stents, for the treatment of MUO 3–5. In 119 cases of extrinsic MUO treated with metal mesh stents, Liatsikos et al6 reported the following adverse effects: hyperplastic reaction, encrustation and tumor ingrowth (45 cases); secondary intervention (17 cases); and stent migration (13 cases).…”

An Update in the Use of JJ Stents

“…[30][31][32] Metallic USs have greater strength, tensile force and resistance to external compression when compared with regular ones; 39 they are cost-effective and useful in both benign and malignant obstructions. 41 Their complications are more common in patients diagnosed with cancer; 38,39 nevertheless, they are still preferred to manage malignant obstructions; 34 there is a risk of failure of up to 35%, 35 especially in patients with obstruction of the wall of the abdominal ureter, lymphatic metastasis, high ECOG-PS grades, and severe preoperative hydronephrosis. [36][37][38] There is a great number of studies that intend to improve USs.…”

“…Chow et al 36 studied 42 patients with malignant ureteral obstruction, in whom a polymeric US was initially inserted, and later on was replaced with a Resonance Metallic Ureteral Stent (Cook Medical LLC, Bloomington, IN, US).Tthey found that the metallic US had higher rates of duration, and should be considered as a first treatment option in these patients. 34 However, it has been demonstrated that up to 35% of these metallic stents fail, mainly in patients with wallinvading prostate cancer; the most common signs of failure are hydronephrosis and an increase in creatinine levels. 35 Radiologic findings enable the clinician to predict the risk of failure of a US.…”