What is Laser?
Laser is an acronym for “light amplification by stimulated emission of radiation”. It produces a highly concentrated beam of light of a given wave length. The commonest laser used for stone is pulsed holmium YAG laser, emitting radiation at 2100nm, and is invisible to the human eye.
What are the indications for laser lithotripsy?
Indications for laser lithotripsy include ureteral calculi, intrarenal small (upto 1 cm size) calculi, or residual small renal calculi after ESWL (Extracorporeal Shock Wave Lithotripsy) / PCNL (Percutaneous Nephrolithotomy). Stones that are difficult to reach by regular rigid instruments can be accessed with flexible scopes and fragmented by laser. Even when stones are located within a cavity of the kidney (calyceal diverticulum) the laser energy can be used to make an opening in the wall of the cavity and all the stones dealt with.
What are the advantages of this method?
The holmium laser is one of the safest, and most effective method of fragmenting all stones regardless of composition. The laser energy is transmitted through a flexible fiber, which can reach all parts of the urinary tract. Since the laser fiber is thin (273µ to 550µ), it can be passed through small caliber endoscopes and hence can also be used in children. It is also therefore very useful in instances where stones are spread out in different parts of the kidneys.
It is also useful when migration of the stone during fragmentation is a risk. In laser lithotripsy, this risk is negligible.
How is the stone broken?
If a stone is in the ureter, a fiber optic instrument called ureteroscope is passed into the ureter and the stone identified. Using holmium laser lithotripsy the stone is vaporized. The goal of holmium laser lithotripsy is to reduce the stone to fine dust/fragments 2 mm or less in diameter, which will pass through the urinary tract easily. If the stone is in the kidney, a flexible ureteroscope can be used to access the stone.
Does this procedure need anesthesia?
Yes, it needs admission in the hospital, and this procedure is commonly performed under general or spinal anesthesia.
What is the success rate of clearance of stones with this procedure?
In smaller size stones, this is in excess of 90%, but otherwise depends upon the size, number and location of these stones.
Are there any disadvantages of the procedure?
The cost of laser lithotripsy is more than the regular lithotripsy, but this is offset by the ability to break a stone in a difficult location.
What is the post operative course?
Generally you are discharged the day after the procedure. You also will be encouraged to have high fluid intake, to keep the daily volume of urine produced to around 2 liters a day. You may have burning sensation while passing urine, pass small fragments of stone in the urine and the urine may be tinged with blood.
What are the complications associated with this procedure?
By and large this procedure is safe. Some risks that are associated with all surgical procedures are the possibility of pain, bleeding and fever. Fever if present will require a change in antibiotic. Rare complications include perforation of the ureter and sepsis.
Will there be significant pain after the procedure?
Some discomfort is inevitable after surgical intervention for stones for a day or two. If needed, your urologist will prescribe medication to help control the pain during the recovery period.
When can one get back to work?
Most patients return to average activity levels within 2 to 3 days. A return to vigorous activity should probably take place after 1 week.
When should I come back after the procedure?
Your first review would be at 2 weeks. If you have a ureteric stent (tube in your ureter), it is usually removed then. You would also need a urine culture to check for any urinary tract infection. Further reviews will be advised by your doctor.
What are signs of a problem postoperatively?
If the fever rises above 102° F, it could be a sign of active infection and should be reported to your urologist. Flank discomfort is common after surgical interventions. However, if the pain becomes increasingly worse or unbearable, despite medication, your urologist should be notified.
How do I prevent recurrence of these stones?
It is advisable to maintain a urine output of 2 liters per day. Your doctor may also advise dietary changes and medications, which will be individualized. Generally a high fiber diet, with avoidance of high calorie foods is recommended.
Laser Fiber within the flexible ureteroscope