All about kidney stones
When a kidney stone becomes lodged in the ureter, which is the muscular tube that drains urine from the kidney to the bladder, it may cause serere pain called renal colic. This pain has historically been compared in intensity to that associated with childbirth. The pain is cause by blockage of the flow of urine from the kidney and the resulting distension of the ureter, and if this is not corrected kidney damage can result. Renal colic normally requires treatment in a hospital A+E department, after the pain is controlled the patient may be discharged to wait for the stone to pass spontaneously, in other situations admission into hospital is required and an operation to place a ureteric stent is performed. The stent allows the urine to flow past the stone and relieves the pain, however can also makes it less likely for the stone to pass and thereafter the patient usualy requires another operation to remove the stone and the stent. The stent itself can cause additional symptoms some of which are very troublesome.
Problems with ureteral stents
It is important that the ureteral stent is removed as soon as possible as it can become encrusted with more stones, which can make subsequent removal more difficult. The length of time a stent can be in the body before this happens varies, with some patients not having any problems for months, in others the stent can start encrusting within weeks. Ureteric stents also commonly cause sympmtoms including blood in the urine, abdominal and loin pain, and pain when passing urine, and an unpleasant feeling of needing to pass urine all the time but being unable to do so. There are new drugs available which can reduce these symptoms while patients are waiting for their stent to be removed.
What causes kidney stones?
Kidney stones can be made from a variety of substances normally excreted in the urine. The most common stones contain calcium and are visible on X-rays. Many biochemical and anatomical abnormalities that predispose to kidney stones have been discovered, it it likely that a combination of mild disturbances in urine composition occuring simultaneously are required for stones to form. These disturbances can occur due to diet, fluid intake, medicines, anatomical abnormalities of the urinary tract and rare biochemical diseases.
What problems can kidney stones cause?
Kidney stones form slowly and often cause no symptoms until they fall down the ureter and cause renal colic. Sometimes they can reach several centimeters in size with no symptoms in the kidney. In others however, small stones in the kidney can cause severe discomfort. A stone that stays in the kidney may also cause urinary infections that keep coming back despite antibiotics. Strangely, the severe pain of renal colic does not always occur when a stone gets stuck in the ureter, and it is possible for the kidney to be permanently damaged by the blockage with maybe only a temporary dull back ache caused. Stones that grow to a very large size in the kidney can cause permanent kidney damage due to chronic infections.
What treatments for kidney stones are available?
The treatment of kidney stones depends upon the size, location and consistency of the stone and also patient factors and choice. Kidney stones can often be treated by shock wave lithotripsy (ESWL) without the need for invasive surgery. At North London Urology we have access to the best lithotripsy service in London. Even at the best centres however, lithotripsy can be ineffective due to the hardness of the stone or size of the patient and for these very hard stones laser surgery is recommended. This technique involves passing very small instruments through the urological tract to the stone, and fragmenting it using targeted laser energy without damaging the surrounding tissues. We have access to specialised operating theatres and perform this procedure regularly. Sometimes stones in the kidney are too large for laser treatment, and these stones require removal through a specially made tract into the kidney through the back. This is called percutaneous nephrolithotomy. We specialise in performing this operation with the patient lying on their back rather than their front and this dramatically reduces operative time and potential complications. Our post operative hospital stays are amongst the shortest, and our complication rates amongst the lowest in the country.
How can I prevent kidney stones?
Once a patient has formed a stone there is approximately a fifty:fifty chance of them forming another within ten years. This chance can be reduced in a number of ways. The stone should always be analysed if possible, and once its composition determined, precise dietry and biochemical abnormalities can often be identified and corrected. Recurrent stone formers, and those with complex stones should undergo a detailed investigation invloving analysing the content of a 24 hour urine collection and special blood tests. In the absence of this, good advice is to drink enough to maintain the urine a clear or light straw colour, avoid added salt and excess animal protein in the diet. A daily intake of citrus fruit juice is also protective for some types of stones.
Minimally invasive treatments for kidney stones
We have particular expertise in Endourological surgery and the treatment of kidney stones. Endourology is the sub-speciality of urology concerned with the investigation and treatment of urological symptoms and diseases using closed or minimally invasive surgical techniques. This involves passing highly specialised instruments through the urological tract or keyhole surgery through the abdomen for the treatment of kidney stones, tumours, and a wide range of other diseases of the kidneys, ureters, bladder, prostate or urethra.
Kidney stones can often be treated by shock wave lithotripsy (ESWL) without the need for invasive surgery and we have access to the best lithotripsy service in London. Even at the best centres however, lithotripsy can be ineffective and for these very hard stones laser surgery is recommended. This technique involves passing very small instruments through the urological tract to the stone, and fragmenting it using targeted laser energy without damaging the surrounding tissues. Sometimes stones in the kidney are too large for laser treatment, and these stones require removal through a specially made tract into the kidney through the back. This is called percutaneous nephrolithotomy.
Endourology also encompasses laparoscopic (keyhole) surgery of the kidneys and ureters. These very advanced surgical techniques allow complete or partial removal of the kidney for benign diseases or cancer, removal of very large stones impacted in the ureter, and also reconstructive procedures for conditions such as pelviureteric junction (PUJ) obstruction in the form of laparoscopic pyeloplasty, and combined laparoscopic stone removal and pyeloplasty.