Introduction
In patients who have, or might have, an obstruction (blockage) of the kidney, an internal drainage tube called a ‘stent’ is commonly placed in the ureter, between the kidney and the bladder. This is placed there in order to temporarily relieve the obstruction.

Your urologist is planning to use such a stent for you

The information presented here explains the benefits to be derived from ureteric stents and mentions some of the drawbacks that patients might experience. It is divided into two parts.

• The first part explains about the urinary system, obstruction of the kidneys and treatment of this obstruction using ureteric stents.

• The second part describes what to expect while the stent is in place and any possible side effects.

The urinary system and ureters
How does a kidney become obstructed?
What is a Ureteric Stent?
How is a ureteric stent put in place?
How long will the stent stay in the body?
How is a stent removed?
Is there an alternative option to the use of a stent?

Introduction
What are the possible side effects?
Duration of the side effects - can they improve?
Can the side effects interfere with daily life?
What other complications are possible?
Is there a possibility of a urinary tract infection?
What care do I need to take?
When should I call for a help?
Further reading

The urinary system and the ureter

How does a kidney become obstructed?

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 treatment, such as shock wave lithotripsy.
• 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 starts from the kidney (pelvi-ureteric junction).
• temporarily, 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. Your urologist will provide further details applicable to you.

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. This is commonly achieved by inserting a ureteric stent to make a channel for the urine to pass and allow the kidneys to drain.

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 to 30 cm. Although there are different types of stents, all of them serve the same purpose (see Figure 2). Your urologist can explain in detail about the different types of stents.

Usually a stent is placed under a general anaesthetic using a special telescope (cystoscope) which is passed through the urethra into the bladder. The stents are then placed in the ureter and kidney via the opening of the ureter in the bladder. The stent may 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 taking a x-ray.

There is no hard and fast rule about this. 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 for up to three months without the need to replace it. When the underlying problem is not a kidney stone, the stent can stay in even longer. There are special stents, which may be left in for a much longer time. Your urologist will tell you how long he expects your stent to remain in place.

How is a stent removed?

Introduction

Commonly noted side effects are:

• The majority of patients with a stent in place will be aware of its presence most of the time.
  
  
  
• Urinary symptoms
  There might be:
  • 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.
  • the stents can also result in a sensation of incomplete emptying of the bladder.
  • very occasionally, especially in women, there is a slight risk of incontinence episodes.

  These effects are possibly due to the presence of the stent inside the bladder causing mechanical irritation. These effects resolve when the stent is removed.

• Discomfort or pain
  Stents can cause discomfort or pain, commonly in the bladder and kidney (loin) area, but sometimes in other areas such as the groin, urethra and genitals. The discomfort or pain may be more noticeable after physical activities and after passing urine.

There is some evidence that some of the symptoms, such as pain while passing urine and blood in the urine, may improve with time. However, this remains unpredictable.

It has been reported that around 20-70% of patients with a stent experience one or more of these side effects.

Medical science and the stent manufacturers are working to develop a stent that will cause the least possible side effects.

Let us look at this in relation to various daily activities:

• Physical activities and sports
  You can carry on with various physical activities while the stent is in place provided the underlying kidney condition and your health allows you to do it. However, you may experience some discomfort in the kidney area and passing of blood in your urine, especially if sports and strenuous physical activities are involved. Sometimes side effects associated with a stent can make you feel more tired than normal.
  
  
• Work activities
  You can continue to work normally with the stent inside your body. However, if the work involves lot of physical activities, you may experience more discomfort. Occasionally side effects, such as urinary symptoms and pain associated with the stent, may make you feel tired. If the stent causes significant problems, you can discuss it with your manager and colleagues so that possible temporary adjustments can be made at your work place.
  
  
• Social life and interactions
  The presence of a stent should not affect this in a significant way. In case you get urinary symptoms such as, increased frequency and urgency, you may need to use public toilets more frequently while taking part in outdoor activities. Occasionally you may need a little more help from family members or colleagues, because of any pain or tiredness you may feel.
  
  
• Travel and holidays
  It is possible to travel with a stent in place, provided the underlying kidney condition and your general health allows this . However, presence of significant side effects associated with the stent may make travel and holidays less enjoyable. Also there is a small possibility that you may require additional medical help while the stent is in place.
  
  
• Sex
  There are no restrictions on your sex life due to the presence of a stent. Few patients experience discomfort during sexual activities. Occasionally the side effects associated with the stent may have an effect on the sexual desire. If you have a stent with a thread coming outside the body through the urethra, sexual activities may be difficult. Care will also be required so as not to dislodge the thread, which could then in turn displace the stent.

• It is essential that you drink at least 1½ to 2 litres (approximately four pints) of fluids, mainly water, a day. This will help to cut down the risk of getting an infection and will reduce the amount of blood in the urine. It will also help in the treatment of stones.
  
  
• If you experience bothersome pain you can take painkillers for relief, on the advice of a doctor.
  
  
• If you have got a stent with a thread coming down from the urethra outside the body, then more care will be needed so as not to dislodge the thread.
  If in any doubt please seek medical help (contact your GP/Local Hospital).

You should contact a doctor or a hospital:-

• if you experience a constant and unbearable pain associated with the stent.
• if you have symptoms of urinary tract infection as mentioned above (e.g. a raised temperature, pain during passing urine and feeling unwell)
• the stent gets dislodged or falls out.
• if you notice a significant change in the amount of blood in your urine.

If you would like to know more about ureteric stents here are the details of some relevant articles for further reading:

1. Ureteral stents- Materials; Endourology update: Mardis HK, Kroeger RM: Urological Clinics of North America, 1988, Vol. 15, No.3, 471-479.

2. Ureteral stents – indications, variations and complications: Saltzman B: Endourology update : Urological Clinics of North America, 1988, Vol.15, No.3, 481-491.

3. Self retained internal ureteral stents: Use and complications: Mardis HK: AUA update series, 1997, Lesson 29, Volume XVI.