2 The technology

Description of the technology

2.1 Memokath‑051 (PNN Medical) is a thermo-expandable, nickel-titanium alloy ureteric stent. It is intended as an alternative to conventional ureteric stents for people with malignant or benign ureteric obstruction. The nickel-titanium alloy has a shape memory effect which is designed to allow the stent to be more easily inserted and anchored in position. A spiral coil design aims to prevent endothelial ingrowth of the tumour or stricture into the stent so that it can be easily removed. Four different versions of Memokath‑051 stents are available (single or double cone, for either antegrade or retrograde insertion), each in several different lengths. Memokath‑051 can be used to treat obstructions elsewhere in the urinary tract, but this is outside the scope of this evaluation.

2.2 The cost of Memokath‑051 used in the company's submission is £1,690 (excluding VAT). This includes the Memokath‑051 stent, a guidewire and a dilator-insertion sheath.

2.3 The company claims in the case for adoption that Memokath‑051 is a safe, simple and reliable ureteric stent with several advantages over other stents:

  • It is better tolerated by the patient, with fewer stent-related symptoms and complications.

  • It avoids the need for stent replacement every 6 months, which saves costs.

  • It restores dignity and improves quality of life.

  • It reduces the risk of tissue ingrowth.

  • It can easily be removed with no side effects.

  • It uses theatre time more efficiently by avoiding the need for major surgery.

Current management

2.4 Ureteric obstruction must be treated quickly to avoid the development of obstructive renal failure. Obstructions can be treated by stenting the ureter, creating a nephrostomy or through reconstructive surgery. The NICE guideline on acute kidney injury states that people with upper urinary tract obstruction should be referred to a urologist. If appropriate, nephrostomy or stenting should be done as soon as possible (at least within 12 hours of diagnosis).

2.5 NICE has produced more specific guidance for malignant ureteric obstruction as a result of prostate or bladder cancer. The NICE guideline on prostate cancer recommends decompression of the upper urinary tract by nephrostomy or inserting a double‑J stent. The NICE guideline on bladder cancer recommends nephrostomy or retrograde stenting (if technically feasible) for people with locally advanced or metastatic bladder cancer.

  • National Institute for Health and Care Excellence (NICE)