Migration of Intraureteral Stents Compared to Conventional Double-J Stents.

The purpose of this study is to determine if stents placed with only one loop in the kidney move more than stents placed with a loop in both the kidney and a bladder. Participants in this study will undergo placement of a stent into the ureter that drains urine from the kidney into the bladder. The stent will be placed in 1 of 2 ways: either with only a loop of the stent is left in the kidney or in the regular manner where a loop of the stent is left in both the kidney and in the bladder. The position of the stent will be measured at the time of placement. When the stent is removed, the position of the stent will be measured prior to pulling the stent.

The ureteral stent is one of the most extensively used tools in the field of urology. They are used for aiding post-operative healing of the ureter, visualizing the ureteral during procedures, and alleviating ureteral obstruction (eg. nephrolithiasis). Double-J stents, which are secured by loops in both the renal pelvis and the bladder, have become most urologists' go-to choice for ureteral stents since they were introduced in the 1970s. Unfortunately, it has been shown that 80-90% of patients with ureteral stents have urinary complaints following stent placement. Interestingly, a recent study suggested utility of intraureteral stents. These stents have one loop in the renal pelvis while their distal end is positioned proximal to the ureteral orifice. The above-mentioned study showed that patients with intraureteral stents had less discomfort as opposed to the those that had double-J stents. Due to the immense number of patients that require ureteral stent placement, this improvement in comfort is very promising for the urological field. However, no one has studied if stents placed intraureterally migrate from the time they are placed to the time they are removed. If stents migrate proximally toward the renal pelvis, it is possible that retrieval could be more difficult, and the ureteral patency established by the stent could be compromised. The objective of this study is to determine if intraureterally placed stents migrate as compared to ureteral stents placed via the conventional method. This study will be a prospective, randomized controlled, single-blinded trial. The subjects will include up to 140 patients (about 70 subjects per group) from ages 1-100 years old that are to undergo stent placement for nephrolithiasis, hydronephrosis, and urological cancer. Prior to the procedure, each patient that has agreed to participate in this study will be randomly assigned to receive a stent placed intraureterally or a stent placed in the conventional manner. After each intraureteral stent is placed via cystoscopy, the distance of the distal end of the stent to the ureteral orifice will be measured via fluoroscopy that was calibrated prior to the procedure. After each double-J stent is placed via cystoscopy, the length of stent that is present in the bladder will also be measured using calibrated fluoroscopy . Subjects will not be informed of which group they are assigned to. When the patients return for stent removal, the previously mentioned distances will be measured again prior to pulling the stent. They will also be asked to complete the ureteral stent symptom questionnaire (USSQ) to assess stent-associated discomfort. The primary endpoint of the study would be stent migration distance (mm). Secondary endpoints would include patient comfort level. All medical records will be accessed on secure devices and networks. All subjects will be assigned a subject number upon enrolled in the study. When a researcher needs to record data from a patient's medical records, they will record this information with the patient's corresponding subject number. Only the researchers involved in this study will have access to the document that includes patient identifiers and their subject number. At the conclusion of this study, the document with patient identifiers and subject numbers will be destroyed. Data will be collected from electronic medical records of patients from ULP (University of Louisville Physicians) Urology.

This study will be a prospective, randomized controlled, single-blinded trial. The subjects will include up to 140 patients (about 70 subjects per group) from ages 1-100 years old that are to undergo stent placement for nephrolithiasis, hydronephrosis, and urological cancer. They will be randomized to one of two groups: intraureteral stent or conventional double-J stent. Upon removal of the stent, migration distance will be measured via fluoroscopy using a calibrated x-ray system.

Patients assigned to this group will undergo placement of an intraureteral stent, a tube that drains urine from the kidney to the bladder and has a loop of tube in only in the kidney and NOT in the bladder. This group will be the experimental group.

Patients assigned to this group will undergo placement of a double-J ureteral stent, a tube that drains urine from the kidney to the bladder and has a loop of tube in both the kidney and the bladder. This group will serve as the control.

This intervention involves the placement of an intraureteral stent, a tube that drains urine from the kidney to the bladder and has a loop of tube only in the kidney and NOT in the bladder. The distal end of the tube will stay in the ureter just proximal to the opening to the bladder.

This intervention involves the placement of a conventional double-J stent, a tube that drains urine from the kidney to the bladder and has a loop of tube in both the kidney and in the bladder.

Inclusion Criteria: Those undergoing ureteral stent placement for nephrolithiasis, hydronephrosis, and urological cancer. Exclusion Criteria: none

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