Kidney stones

Kidney stones are one of the commonest diseases affecting us. These stones are formed mainly from calcium oxalate deposition and crystal formation. Calcium oxalate crystals are not water soluble and the presence of citric acid in the urine allow us to dissolve these crystals and excrete them. But some people have lesser production of citric acid and these people then develop calcium oxalate stones.

Uric acid crystals can often form in the urine and these can serve as a nidus for the development of the calcium oxalate stones. Therefore, patients who have higher uric acid levels in the blood can also develop calcium oxalate stones.

Rarely one can have stagnation of urine and infection in this stagnant urine, which results in production of infective matrix stones.

When urine gets stagnant for a long time then one can develop secondary stones in this stagnant urine, as is typically found in obstructed kidney and obstructed urinary bladder.

What are the main symptoms of stone disease?

Initially the kidney stones are silent and don’t produce any symptoms. But as the stones become larger or start obstructing the urine passage then the patient often encounters pain in the side of the body which radiates down to the lower abdomen or to the testis in men.

In case the stone gets stuck in the urine passage it can also cause red colored urine or blood in the urine. Some stones may also present with infection and foul smell in the urine.

Since nowadays routine ultrasonography is often performed therefore often silent stones can also be detected incidentally .

Diagnosis of stone disease

Stone disease when diagnosed should be immediately evaluated by a trained uro-surgeon. Initially routine tests are performed like ultra-sonography and urine and blood tests.

But CT scan is the most important tool to assess the location and the size of the stone also the kidney function can be easily and accurately assessed by the surgeon.

Therefore today ct scan has become indispensable in assessment of stone disease.

Medical management

Stones cannot be dissolved by medication and stones located inside the kidney cannot be excreted by any medication. However stones which are smaller than 5mm in size and have passed into the ureter, can be treated with a medical trial. Ureter is the narrow tube which carries the urine from each of the kidneys to the bladder. The ureter is narrowest in the lowest part where it enters the bladder. Therefore the stones get most badly impacted in this part of the ureter.

We have a medicine called tamsulosin, which can relax the muscles of the lower most part of the ureter. Therefore, when the stones are smaller than 5mm, and located in the lowest part of the ureter, a medical trial can be attempted.

However, it is very important that, the renal function is good and the patient has no infection or severe pain. If however the kidney is dilated and infected and or there is severe pain, then medical trial should not be tried.

Once we start a medical trial then the patient is kept in close follow up. If the patient develops severe pain or fever then we have to proceed to surgical care immediately.

Medical trial can be continued for only two weeks, if the stone has not passed in two weeks, then we need to convert the management to microsurgical care. Therefore, after two weeks of medical trial we advise the patient to undergo a ct scan to assess whether the stone has passed or not.

If the stone has not passed by two week then it is advisable to convert to endo-surgical management.

1 small ureteral stones less than 6mm are best suited for medical trial

2 stone located in the lower ureter are best suited for medical trial

3 medical trial is possible when the kidney has good function and the patient has no infection and little or no pain

4 medical trial can be carried out for two weeks and not more since the kidney can sustain permanent damage after two weeks.

When is surgical treatment essential in stone disease?

Whenever kidney stones are larger than 6mm it is best to treat them endo-surgically since no medical management is available for renal stones. However, in the case of ureter stones, those which are larger than 6mm, or those which are unlikely to pass with medical management are best treated with laser endo-surgery. Also if medical trial has failed in case of ureteral stones then also we should immediately opt for surgical care.

1 stone in the kidney larger than 6mm are best treated with endosurgery

2 ureter stone larger than 6mm are best treated with surgery

3 those ureteral stone which are not suitable for medical management or medical trial has failed are also selected for surgical care.

trial has failed are also selected for surgical care.

What is stone endo-surgery?

Earlier all stone were operated by open surgery. However these techniques have mostly become obsolete and now open surgery is hardly ever needed in cases of stone disease. Nowadays we use endo-surgery, which means we use very fine telescopes to enter the urinary passage, these being the natural passage of urine flow. Inside the passage the stone is localized and then using energy the stone is fragmented and then removed.

Therefore, the trauma to the patient is very limited and the patient can recover with very less pain.

 

Lasers in stone disease

When the surgeon enters the urine tract and then can visualize the stone, the stone is generally hard and can almost never be pulled out intact. Therefore, the surgeon must use some source of energy to destroy or fragment the stone. This allows the stone to be reduced to small fragments which can then be removed or they can pass out by themselves.

Earlier we used pneumatic hammers, which are micro-hammers to break the stones. But these hammers very often created larger fragments, which could remain back in the urinary system resulting in residual stone burden.

Lasers on the other hand create a plasma bubble which destroys the stone and therefore the chance of residual stones is very limited, also the stone is not pushed back, but destroyed exactly at the site where it is lodged.

Therefore today in any major stone center lasers have become indispensable in the management of stone disease.

 

Why is shock wave lithotripsy not used nowadays?

ESWL or extracorporeal shock wave lithotripsy was very popular in the past. This entailed generation of shock waves, which can pass into the body and fragment the hard stones, while sparing the softer kidney. However this has become almost obsolete now, since the shock waves very often create large fragments, and very often the stone is not cleared completely.

It also may take multiple sessions for the complete clearance of the stone, and in many cases even after multiple sessions the stone may not be cleared completely.

There is also the question of damage to the ureter and the kidney due to the shock waves and also the large sharp and hard fragments of the stone getting impacted into the ureter or the kidney.

1 ESWL results very often in larger fragments of the stone

2 stone clearance may be incomplete even after multiple sessions

3 eswl may result in kidney or ureter damage

4 it is hardly used now since lasers have changed the management of stone disease completely

Why is shock wave lithotripsy not used nowadays?

ESWL or extracorporeal shock wave lithotripsy was very popular in the past. This entailed generation of shock waves, which can pass into the body and fragment the hard stones, while sparing the softer kidney. However this has become almost obsolete now, since the shock waves very often create large fragments, and very often the stone is not cleared completely.

It also may take multiple sessions for the complete clearance of the stone, and in many cases even after multiple sessions the stone may not be cleared completely.

There is also the question of damage to the ureter and the kidney due to the shock waves and also the large sharp and hard fragments of the stone getting impacted into the ureter or the kidney.

1 ESWL results very often in larger fragments of the stone

2 stone clearance may be incomplete even after multiple sessions

3 eswl may result in kidney or ureter damage

4 it is hardly used now since lasers have changed the management of stone disease completely

 

Ureteroscopy and laser lithotripsy

When the stone is located in the ureter then we perform ureteroscopy and laser lithotripsy to destroy the stone. Ureter is the tube which carries the urine from the kidney to the bladder, and ureteroscope is the endoscope which allows us to access the ureter and focus the laser accurately on the stone.

This procedure is performed via the natural urine passage and therefore there is no cut or incision needed for this procedure. This procedure is generally performed under spinal anesthesia, unless there are some other factors demanding general anesthesia.

Once the stone is focused then we use the advanced holmium laser. The laser energy focused on the stone can destroy the stone and therefore the patient can be rendered stone free.

1 ureter is the tube which drains the urine from the kidney to the bladder

2 ureteroscopy is the endoscopic procedure to access the ureter via the natural urine passage

3 we use laser to destroy the stone

4 generally this is performed under spinal anesthesia and the patient can be discharged after one to two nights stay.

 

RIRS

Retrograde intrarenal surgery, or RIRS, is the removal of stones from the kidney, by a flexible uretero-renoscope, introduced via the urine passage.

The flexible uretero-renoscope is a long narrow and flexible endoscope. It is placed via the natural urine passage, under anesthesia. The surgeon is able to negotiate to within the kidney from where he enters the calyceal system. Then once the stone is visualized then a laser is used to destroy the stone.

This procedure is performed for stones which are smaller than 10mm and located within the kidney.

1 retrograde intra renal surgery is meant for stones 6-10 mm in size

2 the surgery is performed under anesthesia

3 the procedure is performed via the natural urine passage and no incision is needed for the access

4 the stones are completely fragmented, but the clearance is confirmed after two month by a CT scan.

 

 

MINI PERC

This is one of the latest additions to the arsenal of the uro surgeon. Herein under anesthesia the procedure is performed. The surgeon places a 5mm or smaller incision and using very advanced microsurgery telescope enters the kidney and removes the stone using laser surgery.

Since the telescopes used are very fine therefore the kidney sustains mnimum trauma and the results are very good.

The patient can return to work very fast.

1 for kidney stones larger than 10mm this is the ideal technique

2 since the telescope used is very fine therefore the trauma to the kidney is very minimal

3 patient has minimum pain and can return to work very soon .

 

PCNL

This is time tested and reliable technique for removal of stones which are very large and located in the kidney. These stones are removed by conventional large caliber nephroscope where in even very large staghorn stones can be removed.

These patients stay in the hospital for two to four days and can return to work after two week.

1 this is designed for very large renal stones more than 20mm in size

2 here we use a large caliber nephroscope for removal of these stones

3 the patient can return to work after two weeks of the surgery

 

PCNL

This is time tested and reliable technique for removal of stones which are very large and located in the kidney. These stones are removed by conventional large caliber nephroscope where in even very large staghorn stones can be removed.

These patients stay in the hospital for two to four days and can return to work after two week.

1 this is designed for very large renal stones more than 20mm in size

2 here we use a large caliber nephroscope for removal of these stones

3 the patient can return to work after two weeks of the surgery

 

Follow up of these cases

Generally, the patients are advised to review after one month with a fresh ct scan. To confirm the complete clearance of the stones. If a stent has been placed it is also removed. After this date the patient can resume normal work and life.

Diet in stone disease

The kidney stones are most often formed due to presence of less citric acid in the urine. Therefore, these patients should be asked to consume one mousambi or orange daily and lifelong. Since these citrus fruits contain high levels of citric acid therefore these patients are not likely to form stones again, as long as the citrus fruit is consumed daily. Since lemon contains large quantities of vitamin c and this can increase the chance of renal stone formation therefore the common lemon, nimbu is best avoided.