The resonance® metallic ureteral stent in the treatment of malignant ureteral obstruction: a prospective observational study

Abstract

BackgroundTo study the outcomes and experiences of using metallic stents in treating patients with malignant ureteral obstruction (MUO), we examined the effects of metallic ureteral stenting using the Cook Resonance® stent in the treatment of MUO.MethodsAll patients who had a Resonance metallic stent inserted between April 2015 and March 2018 at one of multiple facilities were prospectively observed with a 1-year follow-up. The primary outcome was the patency rate of the metallic ureteral stent. The secondary outcomes included the complications (e.g., infection and fever).ResultsAlthough stent insertion was attempted in 50 patients, the stent could not be inserted as a ureteral stent in three patients due to severe ureteral stricture, and one ureteral cancer patient was excluded from the analysis. The remaining 46 patients’ median age was 67 years (range 28–85 years) (16 males, 30 females). Twenty-four patients died during the study; their median survival time was 226 days. The median follow-up period for the censored patients was 355 days (range 16–372 days), and just seven patients were still alive without Resonance failure > 1 year later. The women’s IPSS scores tended to be lower than those of the men. Regarding the OABSS score, although the women’s total score tended to be low, the difference between the men’s and women’s scores was nonsignificant. The bacteria detected from urine culture after stent insertion were more gram-positive than gram-negative.ConclusionMetallic ureteric stenting using the Resonance stent is safe and effective for treating MUO. Subjective symptoms were relatively less in the female patients.

Risk factors in the prediction of long‐term patency of Resonance metallic ureteric stent in malignant ureteric obstruction

“…Previous studies by Abbasi et al and Chow et al showed a mean duration of functioning metallic stent of 5.3 to 7.4 months 11‐14 . Others reported the one year patency rates of Resonance metallic stents in malignancy ureteric obstruction ranged from 60% to 91% 15‐18 …”

Physical Properties of Electropolished CoCrMo Alloy Coated with Biodegradable Polymeric Coatings Releasing Heparin after Prolonged Exposure to Artificial Urine

“…Higher stiffness makes it easier to insert an implant into the ureter, at human body temperature, the stiffness is reduced and the implant more easily adapts to the shape of the ureter, reducing undesirable symptoms in the patient. To improve the functional properties of polymer stents, attempts have been made to functionalize their surfaces with active substances [ 10 , 11 , 12 , 13 , 14 ].…”

“…Clinical studies have shown that metal implants made with metal biomaterials (Co and NiTi alloys [ 12 , 13 , 14 ]) are less susceptible to biofilm formation, thus, limiting the incrustation process. The average service life of metal stents is three times longer than that of polymer stents.…”

Ureteroiliac artery fistula caused by full-length metallic ureteral stenting in a malignant ureteral obstruction: a case report

“…A malignant ureteral obstruction (MUO) can be caused by the direct invasion, lymph node metastasis, and peritoneal dissemination of gastrointestinal or gynecologic cancer that compresses the ureter externally [ 1 ]. Although MUO is a poor prognostic factor with a median life expectancy of < 1 year [ 1 – 5 ], urologists have increasingly been required to intervene in MUO management in the early stages to improve renal function because of the need for aggressive treatment, including chemotherapy, for the primary disease. To relieve a urinary tract obstruction, the retrograde placement of a polymeric ureteral stent or creation of a nephrostomy have been undertaken conventionally.…”

“…A full-length metallic stent (Resonance; Cook Medical, Bloomington, IN, USA) has been developed to overcome disadvantages of these conventional approaches and is widely used globally. Several studies have reported the higher patency and success rate by its strong resistance to extrinsic compression [ 6 ] and its ability to stay in place for 12 months, thereby eliminating the need for stent replacement in patients with MUO [ 3 , 5 ]. Moreover, these stents are reportedly safe for use and have lesser complications than ordinary polymer ureteral stents [ 7 – 9 ].…”