Treatments for Kidney Stones
If a stone (or stones) have been identified, you will have a detailed discussion with your Urologist regarding the options for its further management, ranging from observation with repeat imaging through minimally invasive treatments such as Shock Wave Lithotripsy to surgical interventions including Ureteroscopy and PCNL (see below). Open surgery for stone disease is now vanishingly uncommon, and is usually only needed for kidneys that have become non-functioning with stones in situ, and for which the best treatment is to remove the whole of the kidney rather than just the stone itself.
Small stones in the kidney that are “incidental” (i.e. found on imaging for other reasons, and not causing symptoms) may be observed with follow up imaging and treated if they enlarge or cause symptoms during the follow up interval. Active intervention is likely to be recommended for stones that are symptomatic, causing obstruction, are associated with infection, or are sufficiently large at the time that they are identified that delaying treatment, during which time the stone might enlarge further, would mean that the treatment required would either be more invasive (see below) or less effective in terms of stone clearance.
The list below gives a short summary of the types of treatment that your Urologist might discuss. Each of these may be used in combination with one of the others (for example, it is common to require a JJ stent after stone treatment by ureteroscopy or flexible Ureterorenoscopy, and it is also common for a nephrostomy tube to be inserted after percutaneous treatment of larger stones). The more extensive / complex the stone burden, combined with additional complexity with the anatomy of the patient and any associated medical problems mean a more “tailor made” stone treatment is needed: this means a “strategy” for the clearance of the stone is needed, perhaps with a more major intervention first (such as PCNL) followed by a second phase procedure such as ESWL or FURS to treat any residual stone fragments.
Pain relief is the first priority, particularly in the emergency setting of acute ureteric colic. Regular paracetamol (one gram four times a day) is a good painkiller and provides a useful “baseline” to which the use of anti-inflammatory agents (NSAID) can be added. Not all patients require hospital admission, even in acute ureteric colic. However, in some circumstances, especially in the presence of infection and kidney blockage, or when there is a risk of renal impairment (such as in patients who have only one kidney, or are already known to have reduced renal function, or rarely when there are stones in both ureters at once) admission to hospital is needed to allow one of the active interventions mentioned below to be performed urgently.
Small, symptomless stones in the kidney can be monitored by regular checks with either an Ultrasound of the Kidneys or an X-ray depending upon the characteristics of the stone, and at the recommendation of your Urologist.
Stones in the ureter that have caused acute ureteric colic can also be observed, particularly if they are small and close to the bladder at the time they present with pain. Overall, most stones in the ureter pass by themselves but active treatment will be recommended if the stone shows no sign of passage after 2-3 weeks. Larger stones (for example those more than 6mm or more in size) are less likely to pass spontaneously; your urologist may recommend early pre-emptive treatment in this case, particularly if your pain / discomfort is difficult to control with the painkillers mentioned above.
Over the past decade, there has been a vogue for giving “medical expulsive therapy” (medicines that relax the muscle of the ureter, in the belief that these improved stone clearance). However, there have been a number of large clinical trials recently that suggest there is no benefit to taking these medications, which, like all medicine can have side effects. So the mainstay of management of acute ureteric colic remains effective pain relief and a period of waiting for the stone to pass spontaneously (thereby avoiding intervention) or undergoing one of the active interventions mentioned below and linked to more detailed information in the appropriate BAUS patient information leaflet.
This is the most common treatment recommended for stones less than 10mm in maximum diameter in the kidneys and in the upper ureter (the drainage tube between kidney & bladder). Many stones will clear with a single treatment, but you should expect two or possibly three sessions to clear your stone if it is one of the larger ones. Unfortunately, some stone types do not respond well to lithotripsy and sometimes the fragments do not drain very well, such that some patients may need surgical intervention as an additional treatment. There is also the possibility of acute ureteric colic whilst the fragments pass. If your stone does not responded to two successive treatments with ESWL, it is unlikely to fragment and clear with further treatments and therefore other removal methods should be considered.
ESWL should not be performed in pregnant women or patients who have a bleeding tendency (including patients on heparin, Warfarin or other blood-thinning agents). ESWL may not be possible in patients whose size precludes the ability to of the machine’s focus to reach the distance from the skin to their stone.
Insertion of an Ureteric Stent
As a “stand alone” treatment, this is performed in the emergency situation, when a stone is blocking the ureter with severe pain that does not respond to pain killers. The insertion of a stent under general anaesthetic relieves the blockage so that definitive treatment can be performed at a later stage. In fact, many small stones will often pass spontaneously whilst the stent is in situ, so that removal of the stent alone, rather than requiring a Ureteroscopy, may be possible. If there is concern that there is infection in an obstructed system, this is a Urological emergency, and a JJ stent is an alternative form of drainage to a Nephrostomy Tube (see below) to help treat the infection. Under these circumstances, the stone SHOULD NOT BE TREATED at the same sitting, but deliberately left alone until the patient has recovered properly before being fragmented and removed.
Finally, stents are often placed after stone treatment by ureteroscopy / flexible ureteroscopy to allow the ureter to “recover” from the procedure. Depending upon the presence of any residual stone, these stents are often removed a week or two after the original procedure, usually under local anaesthetic. If there are residual stones requiring a “second phase” procedure, then the stent is likely to remain in situ for longer, as this allows the ureter to passively dilate, and thereby facilitate access with the telescopes at the second procedure.
Percutaneous Nephrostomy Tube Insertion
In the emergency situation of a blocked kidney with an infection due to a stone in the ureter, a nephrostomy drainage tube may be inserted directly into the kidney via the skin of the loin under local anaesthetic. This provides excellent drainage of the kidney and helps to allow the infection to be treated with antibiotics. As mentioned for the use of JJ stents for this type of problem, the stone SHOULD NOT BE TREATED at the same sitting. Since a nephrostomy is an external tube, it is not as convenient to manage as an internal JJ stent, so a JJ stent may be inserted “antegradely” (from above down, via the kidney) by an interventional radiologist, allowing the nephrostomy to be removed before you go home. Sometimes, it is better to leave the nephrostomy in until the operation to treat the stone – your Urologist will explain why this is the case if it applies to you and your stone.
Rigid Ureteroscopy (URS)
Stones in the ureter can be extracted or fragmented with a laser, using a rigid telescope passed through your bladder. This is the main alternative to observation or ESWL for a stone in the ureter causing colic. The advantages include the fact that all stones, however hard, succumb to laser energy, and that a fragment of stone is easier to obtain at the procedure than hoping to catch one after Shock Wave Lithotripsy. However, the disadvantages include the need for hospital admission, and a general anaesthetic, and the fact that, despite being a “minimally invasive treatment” (which does not require an incision, as the telescope is passed via the “natural orifice” of the urethra), it is a surgical procedure that carries certain risks that your Urologist will discuss and explain before you give your informed consent to undergo it. In particular, you may require a temporary stent to be inserted, which can cause bothersome symptoms, and which MUST be removed to avoid future problems from the stent itself.
Flexible Uretero-renoscopy (FURS)
Smaller stones in the kidney can be treated in situ using a flexible Ureterorenoscope (a telescope passed through your bladder to the kidney) and a laser to fragment the stones and/or a basket retrieval device to remove them. As for ureteroscopy above, although “minimally invasive”, this is a technically complex surgical procedure which you and your Urologist will discuss in detail before you chose to go ahead with it. In particular, the pros and cons of this approach compared with ESWL (which is less invasive, and is the main alternative to treating stones smaller than 10mm) and PCNL (which is more invasive, but which gives a better chance of complete stone clearance in a single procedure for stones 15mm and above). Again, there is a high chance that you will require a temporary stent following the procedure – if a second phase operation is needed (i.e. for one of the larger stones), the stent is likely to be needed for a number of weeks between the procedures, but which would ideally be removed at the second operation when the remaining stones have been treated and cleared.
Percutaneous (keyhole) Surgery (PCNL)
This approach is used for large stones in the kidney or upper ureter. It is best chosen as a primary measure for these stones, but can also be used as a “salvage treatment” if the other options have been undertaken first but not succeeded at identifying / fragmenting / clearing the stone for one or other reason. PCNL is the most major intervention performed for stones nowadays (with open surgery more or less confined to the history books, other than for the removal of an entire kidney rendered non-functioning by longstanding obstruction from the stones within). The advantage of a more major procedure is the ability to clear larger volumes of stone in a single procedure, or to treat stones in anatomically challenging positions that would not be easy to reach with a flexible ureterorenscope or to target and drain following ESWL. The disadvantage is greater risk, particularly of bleeding (given their importance to the body, the kidneys have a very rich blood supply) which carries the possibility of needing a blood transfusion or additional manoeuvres to stop the bleeding if it is particularly significant. Whilst uncommon (1-2% overall, but you should discuss this with your urologist if contemplating this type of surgery) this is an important risk and therefore, like ESWL, means patients who have a bleeding tendency, or who are anticoagulated for any reason (taking blood thinners) might not be suitable for this type of stone treatment, and would be better served by a phased ureterorensoscopic approach.