What are Ureteric Stents?
A ureteric stent is a specially designed hollow tube, made of a flexible plastic material that is placed in the ureter. The length of the stents used in adult patients varies between 24 and 30cm. Although there are different types of stents, all of them serve the same purpose, which is to relieve an obstruction in the ureter (the tube that carries urine between the kidney and the bladder) on a temporary basis.
Your kidneys produce urine. Normally there are two kidneys situated in the upper part of the abdomen, towards the back. The urine formed in the kidney is carried to the bladder by a fine muscular tube called a ureter. The urinary bladder acts as a reservoir for the urine and when it is full it is emptied via the urethra (water passage).
What causes the obstruction?
Common causes of obstruction of the kidneys and ureter are:
• A kidney stone or its fragment moving into the ureter, either spontaneously, or occasionally following such treatment as shock wave therapy.
• A narrowing (stricture) of the ureter anywhere along its path. This can be due to various causes e.g. scarring of wall of the ureter, narrowing of the area where ureter leaves from the kidney (pelvi-ureteric junction).
• As a temporary measure, following an operation or after an instrument has been inserted into the ureter and kidneys.
• Occasionally, obstruction can occur because of diseases of the prostate or tumours of the urinary system.
Why this procedure?
Because of the obstruction, pressure can build up behind the kidney. Due to high pressure, the function of the kidneys starts to suffer over a period of weeks. The obstruction can also cause stagnation of the urine, which can lead to infection and further damage to the kidneys. It is, therefore, important to relieve or prevent obstruction of the kidneys.
It is not always possible to identify what has caused an obstruction and to treat this immediately. It is therefore essential to relieve the obstruction on a temporary basis before treatment is carried out. Also, following an operation on the ureters, it takes time for the ureters to heal and a temporary measure to prevent obstruction becomes essential.
What is the procedure?
A stent is usually put in place when you are under a general anaesthetic using a special telescope (cystoscope) which is passed through the urethra (water passage) into the bladder. The stent(s) is then placed in the ureter and kidney via the opening of the ureter in the bladder.
The stent may also be inserted as an additional part of an operation on the ureter and kidney (e.g. ureteroscopy). Occasionally they are placed from the kidney down to the bladder using special x-ray techniques.
The correct position of a stent is checked by x-ray.
The stent has to be kept in place as long as necessary, i.e. until the obstruction is relieved. This depends on the cause of obstruction and the nature of its treatment. In the majority of patients, the stents are required for only a short duration, from a few weeks to a few months. However, a stent in the right position can stay in place for much longer if necessary and using the right kind of stent.
Your urologist will tell you how long they expect your stent to remain in place.
How is a stent removed?
This is a short procedure and consists of removal of the stent using a flexible cystoscope, usually under local anaesthesia.
Before, during and after the procedure:
Ureteric stents are designed to allow people to lead as normal a life as possible. However, they may not be without side effects. In placing a stent, there is a balance between its advantages in relieving the obstruction and any possible side effects. The majority of patients with a stent will be aware of it’s presence most of the time. Common side effects are:
An increased frequency of passing urine.
The need to rush to pass urine (urgency).
A small amount of blood in the urine. This is quite common and the situation can improve with a greater fluid intake.
Stents can also result in a sensation of incomplete emptying of the bladder.
Very occasionally, especially in women, there is a slight risk of episodes of incontinence.
It is essential that you drink at least 1.5 to 2 litres of fluids, mainly water, a day, this will help to cut down the risk of an infection and reduce the amount of blood in the urine. If you experience pain or discomfort you can take painkillers, after consulting your doctor.