COMMENTS © 2006 THE AUTHORS JOURNAL COMPILATION © 2006 BJU INTERNATIONAL 1143 CURRENT OPINION AMONGST RADIOLOGISTS AND UROLOGISTS IN THE UK ON PERCUTANEOUS NEPHROSTOMY AND URETERIC STENT INSERTION FOR ACUTE RENAL UNOBSTRUCTION: RESULTS OF A POSTAL SURVEY Mark F. Lynch, Ken M. Anson and Uday Patel* – Departments of Urology and *Radiology, St George’s Hospital and Medical School, London, UK Accepted for publication 14 June 2006 KEYWORDS percutaneous nephrostomy, ureteric stenting, guidelines, renal unobstruction INTRODUCTION Percutaneous nephrostomy (PCN) and ureteric stenting have been in clinical use for the last three or more decades, but there are still no approved guidelines for the recommended use of these procedures within the UK, or indeed elsewhere. Presently there is controversy on the most effective method of urinary diversion when unobstruction is indicated, whether it be PCN or retrograde ureteric stenting (RUS). Proponents of PCN cite the relative ease with which a large- calibre drainage tube can be placed under sedation, with near 100% success rates [1]. Those who advocate RUS propose that internal drainage can be placed with less risk of significant complications and with no need for external tubes and collection devices [2]. Many factors influence the decision to proceed with unobstruction, and there is limited agreement amongst clinicians about the optimum timing and method of intervention. Such consensus would help healthcare planning, particularly for ‘out-of-hours’ service provision, a topic already debated in radiological reports [3–6]. Thus far there have been only two comparative randomized studies comparing the performance of PCN and RUS [1,2], with relatively few patients in each study (42 and 40, respectively), and the studies might have been under-powered, but at the least they highlighted several points. Pearle et al. [2] reported no difference in superiority or availability of either method, but showed a higher cost associated with RUS. However, Mokhmaliji et al. [1] reported a failure rate of 20% with RUS for stone-induced hydronephrosis, compared with complete success with PCN. A further study by Yossepowitch et al. [7] showed that the success of RUS was 94% and 73% for intrinsic and extrinsic ureteric compression, respectively. As well as the differences in the technical success between these procedures they also diverge in their risk profile. Complication rates after RUS are not as well reported as for PCN, but it is generally agreed that severe bleeding and renal loss have not been reported. However, there is an undoubted major complication rate associated with PCN insertion, with guidelines recommending that these are < 4% [8], with a recent series showing that this value is achievable [9]. In light of the issues on the indications and means of urgent renal unobstruction, we composed a postal survey to establish the level of unanimity or otherwise among radiologists and urologists in the UK. Various typical clinical scenarios were constructed, and accompanying questions were composed to address the indications for urinary diversion and the preferred method to accomplish this. We also evaluated the local provision of current out-of-hours PCN and stenting services. A questionnaire was sent to 153 radiologists and 132 endourologists within the UK. Despite a disappointing response of 19.3% (18.3% of radiologists and 20.5% urologists) there are issues that arose from the results, that prompt discussion. There was a broad similarity in the proportions of radiologists and urologists choosing de-obstruction in each clinical scenario, but there was, in some cases, a complete dichotomy of decision- making within a group. There were areas of strong consensus, as in clinical scenarios of ‘clinical sepsis’ or ‘elevated creatinine and potassium’, where there was 90–100% agreement amongst all clinicians on the need for unobstruction. However, when considering, e.g. ‘ureteric obstruction with hydronephrosis with advanced malignancy for palliation’ only half of all respondents thought that unobstruction was indicated, highlighting the difficulties faced in this contentious scenario. The strongest divergence was that urologists favoured PCN more often than radiologists (mean, median and range of percentage preference for PCN were 48% vs 69%, 49% vs, 74%, and 6–100% vs 18–100% for radiologists vs urologists, respectively; P < 0.001, unpaired t -test). Stents were preferred by urologist only in patients with uncomplicated benign disease and in those with coagulopathy. Reasons for these differences are speculative, as current evidence, although not strong, suggests that the two methods are equally successful despite each having their strengths and weaknesses. The analysis of current service provision in the survey showed only 44% of respondents have an urgent PCN service every day and night, which seemed a large proportion compared to the previously reported values of 11% of hospitals having a separate interventional radiology on-call rota [3]. From our discussions with many clinicians, there seems to be extrinsic logistical and intrinsic patient factors that influence the decision of when and how to de-obstruct. The extrinsic factors are those of availability and priority of theatre and anaesthetic cover out- of-hours, and whether the urologist on call is an experienced endourologist with a high success rate with difficult stent procedures, or a less experienced urologist. Some of the intrinsic or patient factors include the clinical situation, evidence of pelvic malignancy or radiotherapy, or chronic upper ureteric obstruction due to calculi that are difficult to stent. Decision making in the UK is not financially driven, as these procedures do not carry with them any financial reward, unlike in some other healthcare services. The anecdotal view of the urologist is that PCN drainage of an obstructed system is the technique of choice and more readily obtained than RUS. The most significant finding of the present survey is the absence of a consensus view about the best method for urgent renal