[Trials with a new potentially biodegradable ureteral stent. In vitro results with GX 100-15 LB].

We detected a special plastic, which is stable in an acid environment and dissolvable in a basic one. Our preliminary in-vitro results show that the tested material therefore seems principally designed for developing biodissolvable stents for temporary urinary diversion out of the upper urinary tract. Stableness and dissolution could be steered by manipulating the pH.

In vitro results with special plastics for biodegradable endoureteral stents.

Internal ureteral stents are widely used in urologic practice for temporary urinary diversion, but all double-J catheters to date exhibit the same disadvantage; that is, they have to be removed endoscopically, necessitating further intervention. We tested different materials (designated G100X-15xLB and G100X-20xLB) to develop a biodegradable (biodissolvable) endoureteral stent that can be held in place without functional loss yet could be dissolved by changing the environment. The principle of the biochemical background is based on the physiological milieu of the urine.

New endoureteral double-J stent resists extrinsic ureteral compression.

The disadvantages of highly flexible endoureteral (double J) stents in the face of tumor-induced extrinsic ureteral compression are a consequence of insufficient cross-sectional stability, leading to stent compression and thus to hydronephrosis or pyonephrosis. The newly developed tumor stent, which is used in cases of tumor-induced ureteral compression, is available in sizes from 6F to 8F in diameter and 24 to 32 cm in length. The shaft consists of a combination of high-stability plastics that presents sufficient elasticity in length.

Potentially useful materials for biodegradable ureteric stents.

Objectives: To develop and test materials that may be useful in the design and further development of biodegradable ureteric stents.

Materials And Methods: Specimens of two plastics were placed in artificial urine of different pH for 30 days to examine the degree of dissolution of the plastic in alkaline and the stability in acidic conditions.

Results: The specimens remained stable in the artificial urine at pH < 7.

Computed tomography for detection and staging of transitional cell carcinoma of the upper urinary tract.

A total of 91 patients were treated for upper tract urothelial tumors between 1981 and 1991. Preoperative computed tomography (CT) scans and nephroureterectomy for treatment of transitional cell carcinoma were performed in 26 patients. At pathological examination, 28 tumors were diagnosed of which 19 were in the renal pelvis and 7 were in the ureter.