Urological stones form through the sticking together (crystallization) of small crystals inside the calyces, renal pelvis or the ureter. They form primarily inside the kidney and then wander downwards to the ureter. The cause of their formation is mainly due to the presence of the ability for stone formation. This is aided by strong (concentrated) urine which permits the coming together of the crystals to form stones.
The smaller the stone, the more liability for its coming out without interference (spontaneous passage). These spontaneously passable stones are of 2-3 mm in diameter. Larger stones must be treated otherwise.
The urinary stones are of different composition. They may be Calcium Oxalate, Calcium Phosphate, Urate, Cystine or other substances. They form in adults but also to lesser extent in children.
Diet in form of avoiding chocolate, tomato and spinach (Oxalate), milk (Calcium) may help in rare cases and it is not approved scientifically.
So the best way to avoid stones is to drink at least 2 litres of fluids, in particular water, per day. This leads to thinning (dilution ) of the urine to prevent crystallization and stone formation.
The treatment of ureteric stones is dependant on its size and symptoms. If the stone is too small, it left for spontaneous passage.
If the stone is small, the best way is to disintegrate it with the machine. This is the so called electromagnetic shock wave lithotrepsy (ESWL).
If the stone is large and causing widening of the pelvis of the kidney, Then a catheter is inserted into the kidney from outside to reduce its pressure and hence pain. then the stone is disintegrated with ESWL or sometimes with the laser through the endoscope; ureterolitholapaxy (URL).
X- ray of ureteric stone
Note that the stone is projecting along the anatomic course of the ureter downwards S stone
Who qualifies for the ESWL?
Patients who have their stones in the ureter.
Stones which cast on the bones are very difficult to localize and a contrast dye may be used. It is applied into a vein and sometimes through the kidney or ureteric catheter.
How does the disintegration work?
The stone is examined by x-ray examination (urogram). The patient is positioned either on the back or the abdomen according to the accessibility of the stone. Special water pads are put in contact with his body.
The x-ray/energy beamer is positioned on the body. The stone is localised by x-ray and positioned in the middle of the cross at the screen. The stone is shot from outside using a weak energy which is increased to a certain limit. The number of impulses and its frequency are also determined. The patient takes a normal physiological salt solution in the veins. Some patients may need pain medication if they experience it during the treatment.
Patients may experience red urine after the disintegration which is normal.
How does URL works?
This operation is done under general anaesthesia. The bladder is viewed by a cystoscope. The ureter carrying the stone is dilated by a centrally opened thin catheter.
The way to the ureter is defined using contrast dye and x-ray and is secured by a special smooth guide wire. The ureteroscope is inserted through the ureter on this guide wire. The stone is localised. It is held in place by a stone basket. The stone is disintegrated by ultrasonic or laser energy. It is then pulled out of the ureter.
A double-J (D-J) ureteric is put sometimes to drain the kidney and ureter.
--
--
Ureteric stone
Note the dilatation of the ureter arround the stone then
its narrowing behind it.
K = kidney
U = ureter
S = stone
Frequently asked questions (FAQ):
- What is a non-invasive treatment of ureteric stone?
The non-touch disintegration of ureteric stones is done through a special energy which results from electro hydraulic, electromagnetic or piezoelectric source. It is transferred through water and through the body (high water content) to meet the surface of the stone. The surface of the stone is hard. It cannot transfer the energy as it is different from water. The stone reacts through breaking into small fragments.
--
- Is ESWL suitable for all types of stones?
No, it is suitable for stones with less water content. Soft stones do not disintegrate. Also large casting stones (stag horn stones) are difficult to destroy. They are too big and they need many settings to react.
--
- Is ESWL painful?
Mostly not. If the energy meets a part of the chest cage (rib) or bones of the pelvis, it may be painful.
--
- Is it possible to avoid pain during the treatment?
Yes, if pain is experienced, medications are giving through the veins to stop it. Generally you do not experience agonizing pain during treatment.
--
- Shall I become stone free immediately after treatment?
No, you need a few days to weeks to become stone free. This depends on the size of the stone and the degree of disintegration.
--
- Is URL painful?
It is not painful as it is done under anaesthesia.
--
- What are the complications of URL?
Most important is ureteric injury, infection and swelling of the ureter.
--
- When can I get rid of the ureteric stent?
One to a few days after the procedure.
--
- How do I get rid of it?
The stent is pulled out through a cystoscope. This is a very short harmless procedure.
--
- Do I become stone free after URL?
Mostly yes. Sometimes the fragments jump to a high level. You should wait for their spontaneous decent then.
--
- What happen if the ureter becomes injured or swollen?
The doctor should insert a draining tube to the kidney above to drain it and avoid increase of pressure inside it.
--
- How can I help to become stone free?
You should drink at least 2 litres of fluids, preferably water, and jump or move a lot to help the immigration of the small particles of the stones to travel through the ureter to the bladder and then outside.
--
- Should I have medications after the treatment?
I give some capsules which help the propagation of the particles together with water.
--
- How can I avoid stone formation?
This is achieved through drinking of at least 2 litres of fluids (preferably water) per day. This should be increased in hot countries. Please consult your specialist of internal medicine for the amount of fluid, if you have a heart disease.
--
- Is it true that sand and dust are causes of stone formation?
No, this is not true.
--
- Is it true that I can avoid stone formation through certain diets?
This is a controversy. Most preventive measures are done through the intake of fluids and some medications. There is no need for strict diets except in very special types of stones which are rare.
|
