Drainage of Malignant Extrinsic Ureteral Obstruction Using the Memokath Ureteral Stent

The Memokath 051 ureter stent is used for the treatment of malignant or benign ureteric strictures in both men and women. The stent design consists of a tightly-coiled nickel-titanium alloy, with a diameter of 10.5 French (Fr) and a fluted proximal diameter expanding to 22 Fr. The stent is manufactured in multiple lengths which are chosen to position the device across the narrowed area rather than crossing the ureteropelvic or ureterovesical junction. It has a thermal memory system for its predetermined shape; the stent softens at temperatures below 10 degrees Celsius but regains its shape when heated above 55 degrees Celsius.

A JJ stent is a flexible plastic tube that drains urine from the kidney to the bladder and is supposed to stay in place temporarily. There is a coil on each end to keep the stent in place, preventing the stent from migrating down and out from the kidney or up from the bladder into the ureter. The stent can stay in place for few weeks to 3 months or more depending on the indication. If left for more than 6-9 months some stents may get encrusted leading to stone formation around the stent.