Ureteric response to abdominal radiotherapy and metallic double-pigtail ureteric stents: a pig model

To examine the safety and compatibility of full-length metal ureteric stents with abdominal radiotherapy.

Four ureteric stents (Resonance(TM), Cook Urological, Ireland) (RS) and four RSs specially modified to contain thermocouples were placed unilaterally in eight pigs. The contralateral ureters of the same pigs served as their controls, and contained two polymeric ureteric catheters and two similar specially modified to contain thermocouples, while the remaining four control ureters remained intact. All pigs were exposed to abdominal radiotherapy. The dose rate was approximately 5.3 Gy/min and a total radiation dose of 10 Gy was administered. Throughout the treatment the temperature was monitored by the RSs and catheters containing the thermocouples. The pigs were killed at 1 day (four), 7 days (two) and 15 days (two) after treatment, and all ureters examined histologically.

There was no statistically significant increase in RS and catheter temperature throughout the treatment in any of the treated pigs (P > 0.05). All histological lesions reported were due to radiation treatment. There were no differences in histology between the ureters containing RSs and controls.

RS usage is unrelated to any increase in stent temperature during abdominal radiotherapy and does not cause any further deterioration in the histology of the ipsilateral ureter, additional to that caused by the initial treatment.