Emergency Temporising and Definitive Treatment of the Stone
Where the pain of a ureteric stone fails to respond to analgesics or where 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. This has the advantage of not taking much time to perform. However, the disadvantage is that the stone is still present. While the stone may pass down and out of the ureter with a stent in situ, in many instances the stone simply sits where it is and subsequent definitive treatment is still required. Furthermore, though a JJ stent can relieve the pain due to the stone, it can cause bothersome irritative bladder symptoms (pain in the bladder, frequency, and urgency). Having said this, a JJ stent will usually result in passive dilatation of the ureter so that subsequent stone treatment in the form of ureteroscopy is technically easier and therefore more likely to be successful. Similarly, by allowing passive dilatation of the ureter, fragments of stone produced by extracorporeal shock-wave lithotripsy (ESWL) may be more easily able to pass out of the ureter.
3. NONTRAUMATIC RENAL EMERGENCIES 29
General options for definitive treatment of a ureteric stone are ESWL and ureteroscopic stone removal. ESWL is suitable for stones in the upper and lower ureter. Ureteroscopy can be used to treat stones at any level in the ureter, although access and fragmentation of stones in the lower ureter is generally easier (Fig. 3.6).
FIGURE 3.6. Ureteroscopic approach to a lower ureteric stone. Note the presence of 2 guidewires-one is a 'safety' line; the ureteroscope is passed over the other to the level of the stone.
30 J. REYNARD
Whether you decide to carry out definitive stone treatment, and what type of treatment you offer, will depend on local facilities and expertise. Many hospitals do not have daily access to ESWL. In others, surgeons with experience of ureteroscopic stone fragmentation are not always available.