Dietary measures to reduce stone formation. (content reproduced from BAUS website)

How much do I need to drink?
Drinking enough fluid is the most important aspect
of preventing stone formation and will reduce your
risk of stone formation by almost one third. Not
drinking enough fluid can make you urine
concentrated and make stones more likely to form.

Aim to drink 2-3 litres (4-6 pints) of fluid each day
(e.g. water, squash, or fizzy drinks). You should
aim to keep your urine colourless throughout the
day; this equates to a urine output of at least 2 litres (4 pints) per day. In patients
with cystine stones, however, an output of 3.5 litres per day is required.

Tea, coffee & alcohol can be consumed in moderation but the majority of your fluid
intake should be as above.

In addition, it is helpful to try and drink 1 or 2 glasses of water before going to bed
and on rising in the morning.

Should I restrict my protein intake?
Yes. A high intake of animal protein appears to increase the risk of stone formation.
Avoid large portions of meat, fish, eggs, cheese and milk. Aim for 4 of the following
exchanges each day:

50-75g red meat, fish or chicken
2 eggs
½ pint of milk
50g cheese
120g yogurt (1 small pot)

2 of the 4 exchanges should be milk, cheese or yogurt to ensure an adequate intake
of calcium.

You can replace protein with starchy foods (e.g. bread, potatoes, pasta, fruit &
vegetables) to fill you up.

Reducing your protein intake also increases the amount of citrate you excrete in your
urine; citrate is a known inhibitor of stone formation.

Example menu plan:

Breakfast: 2 eggs scrambled on toast
Lunch: Sandwich with 50g cheddar cheese & salad
1 apple
Dinner: 1 small chicken breast (approx 75g)
New potatoes
Vegetables
Fruit salad

Should I restrict the amount of salt I take?
Yes. A high salt intake can contribute to calcium stone formation. Do not add salt to
your food at the table but use pepper, herbs, spices or vinegar as alternative
flavourings. You can, however, add a small amount of salt during cooking.Foods which contain less than 0.4g (40mg) of sodium per serving are low-salt choices and you should aim to keep your salt intake down to these levels. Avoid high-salt, tinned, packet and processed foods (e.g. soups, salted crisps or nuts, tinned meats, meat paste, smoked fish and fish paste).

Do oxalates play a part in stone formation?
You need to avoid oxalate-rich foods to reduce the amount of oxalate in your urine.
The following foods are high in oxalate:

Tea (more than 2-3 cups per day)
Chocolate
Nuts & peanut butter
Cocoa & carob
Strawberries
Rhubarb
Celery, spinach & beetroot
Parsley

It is not necessary to exclude oxalate-rich foods completely; simply eat them in small
amounts.

Does calcium restriction help?
Severe calcium restriction can actually be harmful and increase the risk of stone
formation because it will result in high levels of oxalate in your urine. If you follow the
recommendations above for milk, cheese and eggs, no further action is needed.

The calcium you drink in the water cannot cause kidneys stones and there is no need
to restrict your intake of tap water, drink mineral water or purchase a water softener

Should I take vitamin supplements?
Most vitamins are harmless but do not take Vitamin D preparations, including fish oils
and multivitamin preparations since they increase calcium absorption.

Avoid Vitamin C supplements because they can increase the excretion of oxalate in
your urine.

Summary
A normal calcium, low-salt, low-protein, dietary regime can reduce your risk of stone
formation by a half. Keeping your urine colourless may reduce the risk by a further
one third.

Medications

Your doctor may prescribe certain medications to help prevent kidney stones based on the type of stone formed or conditions that make a person more prone to form stones:

• hyperuricosuria—allopurinol (Zyloprim), which decreases uric acid in the blood and urine
• hypercalciuria—diuretics, such as hydrochlorothiazide
• hyperoxaluria—potassium citrate to raise the citrate and pH of urine
• uric acid stones—allopurinol and potassium citrate
• cystine stones—mercaptopropionyl glycine, which decreases cystine in the urine, and potassium citrate
• struvite stones—antibiotics, which are bacteria-fighting medications, when needed to treat infections, or acetohydroxamic acid with long-term antibiotic medications to prevent infection

People with hyperparathyroidism sometimes develop calcium stones. Treatment in these cases is usually surgery to remove the parathyroid glands. In most cases, only one of the glands is enlarged. Removing the glands cures hyperparathyroidism and prevents kidney stones.

Lithotripsy was first used in Germany in 1984 by Chaussy and colleagues. They used a Dornier HM3 lithotriptor which was very powerful and patients had to be given a general anaesthetic during treatment. As technology has advanced lithotriptors have changed and generally cause less pain and therefore treatments can be carried out with the patient awake although painkillers may have to be used during and after the procedure. Lithotripsy breaks the stone via shock waves which enter the body from outside.

The shock wave may be generated via 3 mechanisms i.e spark gap, electromagnetic, piezoelectric.

The shock wave is targeted onto the stone and the shockwave breaks the stone. Analgesia is usually given during the procedure.The stone will not pass immediately but over the next few days to weeks. Occassionally more than one treatment is required to break the stone. If the stone does not break with lithotripsy surgery may be necessary. Very small (less than 4mm) and very large stones (greater than 2cm) are usually not suitable for lithotripsy.

Shockwave treatment is a non invasive treatment for stones. It is not appropriate for all stones and your specialist will advise you whether this therapy is appropriate for you. The specialist will provide you with analgesia (pain killers) before and after the procedure if necessary. You will usually require an xray  / scan at a time decided by your specialist. Once your treatment is completed you will be able to return home the same day. You will normally require an xray after the treatment to see if your stone/s have broken successfully. Some patients with larger or harder stones may require more than one treatment. The success rate depends on the position, the stone composition and the stone size. Your specialist will provide you with more details regarding the success rates when he sees you.

If lithotripsy fails or is not appropriate as a first line treatment a surgical approach may be necessary.

As with all treatments there is always a risk of complications. These are listed below.

Common (greater than 1 in 10)
Bleeding on passing urine for a short period after the procedure
Pain in the kidney as small fragments of stone pass after treatment (20%)
Urinary tract infection due to bacteria released from the stone during
fragmentation, requiring antibiotic treatment (10%)
Bruising or blistering of the skin in the loin or on the front of the abdomen
Need for repeated ESWL treatments (15-20%)
Failure to fragment very hard stone(s) requiring an alternative treatment (less
than approximately 14%)

Occasional (between 1 in 10 and 1 in 50)
Severe infection requiring intravenous antibiotics (less than 1%) and
sometimes drainage of the kidney by a small drain placed through the
back into the kidney
Stone fragments occasionally get stuck in the tube between the kidney and
the bladder requiring hospital attendance and, occasionally, surgery to
remove the stone fragments

Rare (less than 1 in 50)
Kidney damage (bruising) or infection needing further treatment
Recurrence of stones (less than 1%)

For kidney or ureteric stones that are not suitable for treatment with shockwaves or other forms of surgery a procedure called ureteroscopy may be necessary. This usually involves the insertion of a thin scope which is either rigid or flexible depending on the site of the stone. If the stone is in the ureter ( tube which runs between the kidney and the bladder ) a rigid scope is used. If it is in the kidney a flexible scope is used. A laser fibre is usually inserted through the scope when the stone is reached and is used to break the stone so that fragments can be removed from the ureter or kidney with a small retireval device called a basket. On occassion  it may not be able to remove all the stone at one time and further treatment may be required to render the patient stone free.

The surgeon may have to leave a stent draining the kidney for up to 2 weeks or occassionally longer after the procedure. This is usually removed as a day case under local anaesthetic.

As with any surgical procedure there is a small risk of complications. These are listed below:

Common (greater than 1 in 10)
Mild burning or bleeding on passing urine for short period after operation

Temporary insertion of a bladder catheter
Insertion of a stent with a further procedure to remove it
The stent may cause pain, frequency and bleeding in the urine

Occasional (between 1 in 10 and 1 in 50)
Inability to retrieve the stone or movement of the stone back into kidney
where it is not retrievable (rigid ureteroscopy)
Kidney damage or infection needing further treatment
Failure to pass the telescope if the ureter is narrow
Recurrence of stones

Rare (less than 1 in 50)
Damage to the ureter with need for open operation or tube placed into
kidney directly from back to allow any leak to heal (nephrostomy)
Very rarely, scarring or stricture of the ureter requiring further procedures.

This procedure is usually performed under a general anaesthetic and usually requires a hospital stay between 2 to 5 days. The procedure involves insertion of a wire into the kidney under xray or ultrasound control. Once the wire is placed in the kidney a track is formed over this from the skin to the kidney. The track is then dilated with metal dilators (alken) or with a special narrow balloon (balloon dilatation) and then a sheath placed over this into the kidney. A scope called a nephroscope is then passed into the kidney and the stone broken with a special ultrasound and lithoclast probe. The stone is then removed through the sheath. A small drain (nephrostomy) may be left in the kidney for a few days after the procedure and is removed prior to discharge home. Occassionally a stent may be placed which runs from the kidney to the bladder which may be removed several weeks after discharge.

The success rate varies depending on the size of the stone and complexity of the case. In up to 20% of cases were the stone is large e.g. staghorn calculus more than 1 procedure may be required or additional shockwave treatment may be required before the patient is rendered stone free.

As with all surgical procedures there is the risk of complications. These may include:

Common (greater than 1 in 10)
Temporary insertion of a bladder catheter and ureteric stent/ kidney tube
needing later removal
Transient blood in the urine
Transient raised temperature

Occasional (between 1 in 10 and 1 in 50)
Occasionally more than one puncture site is required
No guarantee of removal of all stones & need for further operations
Recurrence of new stones
Failure to establish access to the kidney resulting in the need for further
surgery

Rare (less than 1 in 50)
Severe kidney bleeding requiring transfusion, embolisation or at last resort
surgical removal of kidney.
Damage to lung, bowel, spleen, liver requiring surgical intervention.
Kidney damage or infection needing further treatment
Over-absorption of irrigating fluids into blood system causing strain on
heart function