A ureteral stent is a thin, flexible tube placed inside the ureter, the passage that carries urine from the kidney down to the bladder. The stent is typically made of plastic and designed with a coil on each end (often called a double-J stent) to keep it securely positioned. This device is frequently used in kidney stone treatment to restore or maintain the flow of urine. The goal is to ensure the kidney drains properly and to facilitate the healing of the urinary tract.
Purpose of the Ureteral Stent
The role of the ureteral stent is to bypass any obstruction that prevents urine from flowing freely from the kidney to the bladder. A kidney stone lodged in the ureter causes pain and pressure, and the stent creates a temporary conduit around the blockage. This immediately relieves the pressure buildup in the kidney, a condition known as hydronephrosis.
Stents are also placed immediately after surgical procedures for kidney stones, such as ureteroscopy. The passage of instruments can cause the ureter lining to swell and become inflamed. The presence of the stent holds the ureter open, preventing collapse and ensuring that stone fragments, blood clots, and urine can still pass through while the ureter heals.
In cases where a severe kidney infection is present alongside a stone blockage, a stent is placed urgently to drain infected urine and decompress the kidney. This urgent drainage is considered a life-saving measure.
Factors Determining How Long the Stent Stays In
The duration a ureteral stent remains in place depends on the specific reason for its insertion, ranging from a few days to several weeks. A common timeframe following a routine stone procedure is usually between three to seven days. The physician determines the necessary dwell time based on the patient’s healing timeline and the nature of the urinary tract injury.
The type of procedure performed is a variable in the duration of stenting. If a stent is placed temporarily to drain an infected kidney, it may only remain for a few days to stabilize the patient. Conversely, after a complex ureteroscopy or if the ureter lining was injured, the stent may remain for one to two weeks to ensure adequate healing.
Another consideration is the status of the stone fragments; if the stone was broken up into small pieces that need time to pass, the stent will stay in longer to facilitate this process. The risk of the stent developing encrustation, where mineral deposits accumulate on the tube, increases the longer it stays in the body.
Stents are rarely left in for more than a few months without a plan for replacement or removal, as encrustation makes removal more complicated and can damage the ureter. Leaving a stent in longer than the prescribed period significantly raises the risk of complications. Stent encrustation can occur in nearly three-quarters of stents left in past 12 weeks, which can necessitate an additional, more invasive procedure to remove the calcified tube.
The Stent Removal Process
The removal of the ureteral stent is generally a quick outpatient procedure, with the method depending on whether the stent was placed with an extraction string. If the stent was placed for a short duration, it may have a thin string attached that extends out through the urethra. The string allows the patient or a healthcare provider to gently pull the stent out in the office or at home.
For stents that were in place for a longer period and do not have an external string, removal requires a procedure called cystoscopy. During this process, the physician inserts a thin, flexible scope through the urethra into the bladder. The scope allows the doctor to visualize the coiled end of the stent and grasp it with a small instrument before gently pulling it out.
Patients typically report a brief moment of discomfort or a pulling sensation during the removal. Following removal, it is common to experience a temporary increase in urinary urgency or frequency, along with possible blood in the urine (hematuria). These temporary symptoms usually resolve within 24 hours as the urinary tract adjusts.