Laser Kidney Stone Surgery (Ureteroscopy)

Overview

Surgical options for patients with symptomatic kidney stones include extracorporeal shock wave lithotripsy (ESWL), ureteroscopy, and percutaneous nephrolithotomy  (PCNL). Your renal anatomy, stone composition, and body habitus all play major roles in determining outcomes and operative approach.

The role of ureteroscopy over the last ten years has undergone a dramatic evolution, due to improvements in the ureteroscope size and deflection capabilities, video-imaging, miniature baskets and instruments, and in lithotripsy (stone breakage) with the advent of holmium laser. Over 25% of all kidney stone surgeries are now done using small ureteroscope technology.

About kidney stone surgery

Once you are asleep, your urologist passes a small lighted tube (ureteroscope), through the urethra and bladder and into the ureter to the point where the stone is located. If the stone is small, it may be snared with a basket device and removed whole from the ureter. If the stone is large and/or if the diameter of the ureter is narrow, the stone will need to be fragmented, which is usually accomplished with a laser. Once the stone is broken into tiny pieces, these pieces are usually removed from the ureter. In most cases, to ensure that the kidney drains urine well after surgery, a ureteral stent is left in place.

Ureteroscopy can also be performed for stones located within the kidney. Similar to ureteral stones, kidney stones can be fragmented and removed with baskets. Occasionally, a kidney stone will fragment with a laser into very small pieces (grains of sand), too small to be basketed. The urologist will usually leave a stent and allow these pieces to clear by themselves over time. Lastly, if the ureter is too small to advance the ureteroscope, the urologist will usually leave a stent, allowing the ureter to “dilate” around the stent, and reschedule the procedure for 2-3 weeks later. Ureteroscopy is usually performed as an outpatient procedure. Some patients, however, may require an overnight hospital stay if the procedure proves lengthy or difficult.

What are the risks?

As with any major surgery, complications, although rare, may occur with ureteroscopy. Potential risks and complications with this operation include but are not limited to the following:

• Stent pain: About 50% of patients who undergo ureteroscopy and have a stent will have “stent pain,” and this is by far the most common risk/complaint following ureteroscopy. A stent is a soft plastic tube (about half the size of IV tubing) that allows the kidney to drain to the bladder regardless of edema or obstruction. Not only can the stent “rub” on the inside of the bladder, causing a feeling of needing to urinate/overactive bladder, but also the stent allows urine to pass up from the bladder to the kidney during urination – causing symptoms from a warm, tingling sensation to intense pain in the affected flank. Ask your surgeon about the risks/benefits of a ureteral stent following surgery.
• Stone fragments: Residual stones within the kidney or ureter may be present up to 40% of the time following ureteroscopy, depending on the original stone size and location. These stone fragments will be seen and addressed on follow-up imaging. Ask your urologist to give you some idea of success rates for your particular stone size and location.
• Ureteral injury: Injury to the ureter is the most common intra-operative complication during ureteroscopy. The reported risk of perforation ranges greatly, depending on whether it is defined as a complete perforation (0.1-0.7% — think of this as a hole through the entire ureter), a partial perforation (1.6% — a hole nearly through the entire ureter), or mucosal tear/scrape (5% — these are similar to a sore on the inside of the mouth). Almost 100% of these will heal with prolonged stenting (anywhere between 2 – 4 weeks). Should a large perforation occur, your urologist may chose to stop the procedure and return on another day when the ureter has had time to heal. Should your urologist not be able to place a stent after a perforation, a tube called a “nephrostomy tube” will be placed through the skin of your back into the kidney. This tube temporarily diverts the urine away from the hole and out into a bag until healing can occur and the hole close.
• Ureteral stricture and avulsion: Ureteral strictures (scar tissue within the ureter) and ureteral avulsion (complete dissociation of the ureter from the kidney) are the most feared complication of ureteroscopy. Fortunately, due to the advent of small ureteroscopes and heightened surgeon awareness, the risk of avulsion (0.05%, 1/2000) or stricture (0.2%, 1/500) is rare.
• Haematuria and infection: Bleeding and infection are certainly possible following ureteroscopy (5%), but most of these are self-limiting and resolve with hydration and antibiotics, respectively.

What to expect after surgery

• Immediate post-operative period: After the surgery you will be taken to the recovery room. If a urinary catheter (foley) was placed during surgery, this may be removed by your nurse once you are awake, alert, and moving comfortably. Once your pain is controlled and you are able to urinate, you may be discharged from the recovery room to home. Expect blood in the urine with almost every urination. With time and hydration, the urine should slowly turn from a watermelon red colour to pink to clear. You may have stent pain or bladder spasms (see complications of ureteroscopy above) that can be helped by overactive bladder medications or by an indwelling foley catheter. Due to instrumentation, most patients will receive 4-5 days of oral antibiotics to prevent a urinary tract infection.
• Postoperative Pain: Most patients after ureteroscopy experience mild to moderate pain in the flank and/or bladder area. This is generally well controlled by use of oral narcotics (pain medication) such as Percocet or Vicodin. As you get further out from your ureteroscopy, you may be able to decrease the strength of the medication.
• Ureteral Stent: Almost always after ureteroscopy, a small tube called a ureteral stent will be placed. The stent serves to facilitate drainage of urine down to the bladder.  At a later date, the stent will be removed in the office by your surgeon. You may experience bladder spasms related to the ureteral stent that was placed at the end of your procedure.
• Nausea: Nausea is fairly common following any surgery especially related to general anaesthesia. This is usually transient and is self-limiting. Should you have excessive nausea and vomiting, you should contact your surgeon for advice.
• Showering:  Patients can shower immediately upon discharge from the hospital
• Activity:  Patients may begin driving once they are off all narcotic pain medication. Most patients are able to perform normal, daily activities within 5-7 days after ureteroscopy. However, many patients describe more fatigue and discomfort with a ureteral stent in the bladder. This may limit the amount of activities that you can perform.
• Diet: Most patients only desire clear liquids for the first 24 hours following ureteroscopy, as your intestinal function may be sluggish due to the effects of surgery and general anaesthesia. Following this period, Patients may resume a regular diet as tolerated.
• Fatigue: Fatigue is quite common following surgery and should subside in several days following surgery.
• Constipation/Gas Cramps: You may experience sluggish bowels for several days following your ureteroscopy as a result of the anaesthesia. Suppositories and stool softeners are usually given to help with this problem. Taking a teaspoon of mineral oil daily at home will also help to prevent constipation. Narcotic pain medication can also cause constipation and therefore patients are encouraged to discontinue any narcotic pain medication as soon after surgery as tolerated.

What are the advantages of ureteroscopy compared to other stone treatments?

• Provided that the kidney stones are an appropriate size and location, an advantage of flexible ureteroscopy is that it allows entry into all parts of the kidney. As long as the ureter is large enough to allow the ureteroscope to pass, there is a good chance that the stone can be broken and removed with one surgery.
• Compared to SWL, a kidney or ureteral stone can be seen under direct vision by the ureteroscope, allowing lithotripsy with lasers followed by basketting and removal. With shock wave lithotripsy, patients are asked to pass stone fragments themselves, causing potential additional pain or obstruction. Additionally, shock wave lithotripsy may not break up very dense, hard stones (termed SWL resistant stones). Ureteroscopy with a contact holmium laser can break up any stone, as long as the stone itself is accessible to the ureteroscope. Additionally, ureteroscopy allows the treatment of stones are invisible on plain x-ray (“acid” stones).
• Compared to percutaneous procedures, the ureteroscope is passed through natural body orifices and involve no skin incisions. It is an outpatient procedure, where PCNL requires at least an overnight hospital stay. Certain patient groups who cannot be treated with ESWL or PCNL (such as patients on blood thinners, women who are pregnant, the morbidly obese, and airline pilots/astronauts) can be treated safely and effectively by ureteroscopy.