392 CHAPTER 8 Stone disease

Ureteric stones: indications for intervention to relieve obstruction and/or remove the stone

-Pain that fails to respond to analgesics or recurs and cannot be controlled with additional pain relief.

-Fever. Have a low threshold for draining the kidney (usually done by percutaneous nephrostomy).

-Impaired renal function (solitary kidney obstructed by a stone, bilateral ureteric stones, or pre-existing renal impairment that gets worse as

a consequence of a ureteric stone). The threshold for intervention is lower.

-Prolonged unrelieved obstruction. This can result in long-term loss of renal function.1 How long it takes for this loss of renal function to occur is uncertain, but generally speaking, the period of watchful waiting for spontaneous stone passage tends to be limited to 4–6 weeks.

-Social reasons. Young, active patients may opt for surgical treatment because they need to get back to work or their childcare duties, whereas some patients will be happy to sit things out. Airline pilots and some other professions are unable to work until they are stone

free.

Emergency temporizing and definitive treatment of the stone

When the pain of a ureteric stone fails to respond to analgesics or renal function is impaired because of the stone, then temporary relief of the obstruction can be obtained by insertion of a JJ stent or percutaneous nephrostomy tube. (Percutaneous nephrostomy tube can restore efficient peristalsis by restoring the ability of the ureteric wall to coapt.)

JJ stent insertion or percutaneous nephrostomy tube can be done quickly, but the stone is still present (Fig. 8.13). It may pass down and out of the ureter with a stent or nephrostomy in situ, but in many instances it simply sits where it is and subsequent definitive treatment is still required.

While JJ stents can relieve stone pain, they can cause bothersome irritative bladder symptoms (pain in the bladder, frequency, and urgency). JJ stents do make subsequent stone treatment in the form of ureteroscopy technically easier by causing passive dilatation of the ureter.

The patient may elect to proceed to definitive stone treatment by immediate ureteroscopy (for stones at any location in the ureter) or ESWL (if the stone is in the upper and lower ureter—ESWL cannot be used for stones in the mid-ureter because this region is surrounded by bone, which prevents penetration of the shock waves) (Fig. 8.14).

Local facilities and expertise will determine whether definitive treatment can be offered immediately. Not all hospitals have access to ESWL or endoscopic surgeons 365 days a year.

1 Holm–Nielsen A, Jorgensen T, Mogensen P, Fogh J (1981). The prognostic value of probe renography in ureteric stone obstruction. Br J Urol 53:504–507.

URETERIC STONES 393

Emergency treatment of an obstructed, infected kidney

The rationale for performing percutaneous nephrostomy rather than JJ stent insertion for an infected, obstructed kidney is to reduce the likelihood of septicemia occurring as a consequence of showering bacteria into the circulation. It is thought that this is more likely to occur with JJ stent insertion than with percutaneous nephrostomy insertion.

Figure 8.13 A JJ stent.

Figure 8.14 Ureteroscopic stone fragmentation for a lower ureteric stone.

394 CHAPTER 8 Stone disease

Ureteric stone treatment

Many ureteric stones are 4 mm in diameter or smaller and most such stones (90%+) will pass spontaneously, given a few weeks of watchful waiting, with analgesics for exacerbations of pain.1,2

Average time for spontaneous stone passage for stones 4–6 mm in diameter is 3 weeks. Stones that have not passed in 2 months are much less likely to do so, though large stones do sometimes drop out of the ureter at the last moment.

Indications for stone removal

-Pain that fails to respond to analgesics or recurs and cannot be controlled with additional pain relief

-Impaired renal function (solitary kidney obstructed by a stone, bilateral ureteric stones, or pre-existing renal impairment that gets worse as a consequence of a ureteric stone)

-Prolonged unrelieved obstruction (generally speaking, ~4–6 weeks)

-Social reasons. Young, active patients may opt for surgical treatment because they need to get back to work or their childcare duties, whereas some patients will be happy to sit things out. Airline pilots and some other professions are unable to work until they are stone free.

These indications need to be related to the individual patient—their stone size, their renal function, presence of a normal contralateral kidney, their tolerance of exacerbations of pain, their job and social situation, and local facilities (the availability of surgeons with appropriate skill and equipment to perform endoscopic stone treatment).

Twenty years ago, when the only options were watchful waiting or open surgical removal of a stone (open ureterolithotomy), surgeons and patients were inclined to sit it out for a considerable time in the hope that the stone would pass spontaneously.

Currently, the advent of ESWL and of smaller ureteroscopes with efficient stone fragmentation devices (e.g., the holmium laser) has made stone treatment and removal a far less morbid procedure, with a far smoother and faster post-treatment recovery. It is easier for both the patient and the surgeon to opt for intervention, in the form of ESWL or surgery, as a quicker way of relieving them of their pain, and a way of avoiding unpredictable and unpleasant exacerbations of pain.

It is clearly important for the surgeon to inform the patient of the outcomes and potential complications of intervention, particularly given the fact that many of stones would pass spontaneously if left a little longer.

1 Segura JW, et al. (1997). Ureteral stones guidelines panel summary report on the management of ureteral calculi. J Urol 158:1915–1921.

2 Miller OF, et al. (1999). Time to stone passage for observed ureteral calculi. J Urol 162:688–691.