Use of the PercSys MicroStent Device to Alleviate Ureteral Stone Symptoms and Hydronephrosis

• Relief of hydronephrosis (fluid in kidney causing kidney swelling) [ Time Frame: 1-2 weeks following stent placement ] [ Designated as safety issue: No ]
  Patients will return for radiographic test(s) after the stent placement as determined by the physician which can include kidney-ureter-bladder (KUB) x-ray, renal and bladder ultrasound, or CT scan. This imaging helps determine 2 things: the degree of kidney swelling (hydronephrosis), stent migration and whether their stone is still present or not.
  
  

• Pain relief [ Time Frame: 0, 1, 2, 3, 4, 5, 6, 7 post stent placement, and days 1 and 7 post stent removal ] [ Designated as safety issue: No ]
  Before stent placement the subject will complete Visual Analog Scale (VAS) questionnaire. After stent placement and discharge home study questionnaires will be completed each day at the end of the day, until stent removal which will be in approximately 7 days. Each VAS questionnaire takes approximately 10 minutes to complete. The subject will be instructed to bring these at their clinic visit for stent removal at Vancouver General Hospital. After the stent removal 2 more questionnaires are completed, at 1 day and at 7 days. These are sent back in a stamped return envelope.
  
  
• Migration of stent [ Time Frame: 1-2 weeks following stent placement ] [ Designated as safety issue: No ]
  Patients will return for radiographic test(s) after the stent placement as determined by the physician which can include kidney-ureter-bladder (KUB) x-ray, renal and bladder ultrasound, or CT scan. This imaging helps determine 2 things: the degree of kidney swelling (hydronephrosis), stent migration and whether their stone is still present or not.
  
  

This study is to evaluate a new type of ureteral stent to relieve kidney obstruction from a stone lodged in the ureter. This stent would be placed when a patient presents with pain in the Emergency Room or clinic in a patient that has no signs of infection. It is designed to continue drainage of the kidney and unlike other ureteral stents, is also designed to help dilate the ureter to facilitate spontaneous stone passage. This means the stent may also be therapeutic and the patient would be less likely to undergo another procedure to have the stone removed. Research performed at the Stone Centre at VGH shows that in ex vivo pig kidneys, this stent provides very good urinary drainage of the kidney. This has been published in a peer-reviewed journal (Lange D, Hoag NA, Poh BK, Chew BH. Drainage characteristics of the 3F MicroStent using a novel film occlusion anchoring mechanism. J Endourol. 2011 Jun;25(6):1051-6.).