Management of stones: recent developments, new concepts and definitions
For those of us who were urological trainees in the 1980s, nothing since has compared to the revolution in the management of urinary tract stone disease that occurred then. The massive and rapid development of endourological techniques – percutaneous nephrolithotomy, then rapidly following this lithotripsy and in its wake ureteroscopy and ureterorenoscopy with means of stone fragmentation and pulverisation – completely changed the means of management of renal and ureteric stones. The last 30 years has seen more gradual evolution, with consolidation of techniques that have occurred largely on the back of finer endoscopic instruments with better optics and cameras and the move to third-generation lithotripters together with experiences shared.
This year’s annual meeting of the EAU in Madrid was, as in the last 10 years, demonstrating steady progress in this area against the increased prevalence of stone disease both in Europe and North America. The reasons for this increase is in part felt to be due to rising levels of obesity causing a rise in the metabolic syndrome and thus in turn increased risk factors to form stones. In addition, Galan and Skolarikos drew attention to a further increased risk of urolithiasis in patients undergoing bariatric surgery who have added dehydration and disturbance of oxalate absorption in the small bowel giving increased risk of stone formation.
An excellent series of papers dealt with the particular problem of lower pole renal stones. Micro PCNL has now come of age, with the design of specialist instruments now more widely available, and is certainly a very good alternative to standard PCNL, lithotripsy and flexible retrograde ureterorenoscopy. Three views were put as to how to deal with lower pole caliceal stones, which remains a very common and not always successful area to treat. Trinchieri showed how modern lithotripsy can still be effective, yet overall has limitations, with clearance rates of only 80% being typical. Various manoeuvres may improve this, the provision of drugs (tamsulosin and nifedipine) and patient positioning together with improved acoustic coupling may all increase stone clearance. Retrograde endoscopy certainly is more possible and less hazardous with modern flexible instruments and accessories, yet their delicacy and the need to gain access up the ureter and thus potentially damaging the ureter remains and the need for a JJ stent may make this less attractive than the third option discussed of micro PCNL. Certainly Hoznek’s exposition of this technique in expert hands was persuasive and offers a more certain means of clearing the inferior pole calix of a stone of 1cm or more. His and others’ data suggest a significant reduction in complications over standard PCNL, particularly blood loss and all that follows.
A good review of the complications that can follow ureteroscopy was given by Geavlete and served as a warning to all of us performing this type of surgery: as he stated, honesty in reporting such complications is vital and its avoidance by proper training, experience and the use of modern equipment are all paramount. Significant complications should be 5% or less in incidence, but he emphasised the importance of their recognition and their treatment.
Wendt-Nordahl spoke on the important topic of radiation exposure not only to the patient but also to the practitioner treating upper urinary tract stones. In both groups it remains of extreme importance to cut down unnecessary radiation and although appropriate planning and treatment of upper tract stones generally requires some radiation, this must be carefully monitored and controlled.
Moving away from surgery and lithotripsy, the prevention of stones in stone formers was emphasised in talks by Reis Santos and Siener. There remains the overriding need for hydration (of course first recognised by Hippocrates) and the well-known tip of making patients measure their urinary output such that they produce two to two and a half litres of urine per 24 hours as the means of deciding fluid intake was emphasised. Similarly, the emphasis on increasing citrate levels in urine was made by both speakers and the fact that this can be easily achieved by drinking a litre of fresh orange juice a day or by squeezing two lemons per day are both well-established pieces of advice.
Stone disease remains an extremely large and important part of urology and the gradual evolution of knowledge and techniques was helpfully covered at the sessions on stone disease at the EAU.
Consultant Urological Surgeon, London Urology Group