Evolution of stone management in Australia

Transcription

1 Evolution of stone management in Australia Ming-Chak Lee and Simon Virgil Bariol Department of Urology, Westmead Hospital, Sydney, Australia OBJECTIVE To examine trends in the operative management of upper urinary tract stone disease in Australia over the past 15 years. MATERIALS AND METHODS What s known on the subject? and What does the study add? There is very little contemporary data regarding stone management in Australia. This study assesses the impact of technological advances on stone management practises, and raises questions as to why there is an increasing rate of intervention for stone disease in Australia. Knowledge of management trends as demonstrated in this paper give individual surgeons a guideline for contemporary practise in this country. The Medicare Australia and Australian Institute of Health and Welfare databases were used to determine the annual number of renal colic presentations and procedural interventions undertaken for stone disease. RESULTS In Australia over the past 15 years, the annual number of procedural interventions for upper urinary tract stones has increased, primarily due to the rising number of endoscopic procedures performed. During this period, shock wave lithotripsy numbers have remained steady whilst open and percutaneous procedures have been in decline. CONCLUSION The introduction of and subsequent preference for less invasive techniques has changed the management pathway of patients presenting with stone disease in Australia. Further studies are necessary to determine whether this escalation in endoscopic procedures is due to an increase in the incidence of stone disease, earlier detection, a lower intervention threshold or a higher retreatment rate. KEYWORDS kidney, kidney stones, urolithiasis, treatment, epidemiology, Australia INTRODUCTION The management of upper urinary tract stone disease has evolved significantly in the last three decades. Improvement in endoscopic equipment and the discovery of shock wave lithotripsy (SWL) has resulted in a paradigm shift in the way stones are now managed. With the recent expanding use of laser technology, the numerous operative modalities available have led to a rise in multi-step interventions, repeat treatments and combination therapy, which have the potential to increase the number of treatments performed. Therefore, while minimally invasive techniques may be associated with reduced morbidity, modern treatments are often less streamlined [1,2 ]. The limited availability of comprehensive epidemiological health data in Australia has made it difficult to analyse trends in the management of stone disease. This is particularly unfortunate given our country s unique racial diversity, geography, climate and diet, all of which can affect the incidence of the disease. Management trends from overseas may not apply to Australia due to differences in health funding and delays in the implementation of new techniques. Our objective was to examine trends over the past 15 years in the presentation and management of upper urinary tract stone disease in Australia. MATERIALS AND METHODS The Medicare Australia database was used to determine the number of procedures performed for stone disease annually between 1995 and 2010 using item number reports, which we subsequently grouped into four categories for analysis (see Table 1 ). The Medicare Australia database includes all claimed procedures which are performed by a registered provider and qualify for a Medicare Benefit. Services provided to public patients in public hospitals and services which fall under the Department of Veterans Affairs National Treatment Account were not included [3 ]. Information regarding age, gender and racial origin were also unavailable. The Australian Institute of Health and Welfare (AIHW) database was used to calculate the number of renal colic presentations and stone management procedures in Australian hospitals. Despite minor year-to-year variations in the data collection process, the database covers essentially all medium to large public and private hospitals with the exception of those operated by the Department of Defence and correctional authorities [4 ]. Again, the stone management interventions have been categorized in four groups: (i) open procedures; (ii) percutaneous nephrolithotomy (PCNL); (iii) SWL; and (iv) endoscopic procedures. Only data from 108, SUPPLEMENT 2,

2 LEE and BARIOL 1 to were available. Due to the potential for patients to be billed for more than one item number in a single operation, the absolute number of patients managed non-operatively could not be determined. RESULTS In 1995, there were 4842 stone treatments claimed under Medicare Australia, with this figure more than doubling to by 2010 ( Fig. 1 ). Even accounting for the increase in population, the per capita rate of interventions has risen from 27 per in 1995 to 53 per in 2010 [ 5,6 ]. Most of this rise is attributed to the considerable increase in endoscopic stone procedures. In 1994, claimed items from endoscopic stone treatments numbered 1579 and represented only 32.6% of total procedures, compared with 57.0% for SWL. By, the proportion of SWL and endoscopic treatments was approximately equal. Over the past decade, however, the number of endoscopic interventions has increased to 8232 or 69.7% of total procedures at the expense of all other treatment modalities (Fig. 2 ). Whilst absolute SWL numbers have remained fairly steady over the 15 years examined, PCNL has been in decline, from almost 6% of Medicare claimed procedures in 1995 to less than 3.5% in Open stone removal techniques currently comprise less than 0.5% of all stone procedures. The AIHW database demonstrates similar trends amongst the four stone management categories. A comparison of treatment numbers against renal colic presentations revealed roughly equal usage of SWL and endoscopic procedures at around 18 per 100 presentations in 1 for both groups. By , however, 28% of patients presenting with renal colic were managed with retrograde endoscopic ureteroscopy or pyeloscopy, representing an absolute increase of 10%. This corresponded to only a small 2% decline in the rate of SWL to 16% ( Fig. 3 ). Using the two-way ANOVA test comparing stone management techniques between 1 and revealed a significant increase in the proportion of renal colic presentations treated endoscopically compared with SWL ( P = 0.025). Open and percutaneous interventions TABLE 1 Categorization of stone management procedures and corresponding Medicare item numbers Procedure Item number(s) Group 1 (open) Nephrolithotomy, pyelolithotomy and 36540, 36543, ureterolithotomy Group 2 Percutaneous nephrolithotomy 36639, 36642, 36645, Group 3 Shock wave lithotripsy Group 4 (endoscopic) Ureteroscopy with laser/basket and pyeloscopy with laser/basket 36806, 36809, 36654, FIG. 1. Number of stone treatment procedures claimed under Medicare Australia between 1995 and Number of procedures FIG. 2. Number of procedures claimed under Medicare Australia for different stone treatment modalities between 1995 and Number of procedures x x x x x x x x x x x x x x x x x Open nephrolithotomy, pyelolithotomy and ureterolithotomy Percutaneous nephrolithotomy Shockwave lithotripsy Ureteroscopy and pyeloscopy 30

3 EVOLUTION OF STONE MANAGEMENT IN AUSTRALIA FIG. 3. Proportional comparison of stone treatment modalities for renal colic presentations between 1 and FIG. 4. Rate of procedural intervention for renal colic presentations in Australia from to Interventions per 100 presentations represent only a small component of stone disease treatment in Australia with less than 3% of renal colic presentations currently managed with either operative modality. The AIHW data also revealed an increasing trend in the percentage of patients with renal colic presentations receiving operative intervention for upper urinary tract stones, from 40% in 1 to 47% in (Fig. 4 ). DISCUSSION Although the data source is incomplete, analysis of national trends in stone disease management is highly informative and worthwhile. It is clear that innovations in stone treatment over the past three decades have revolutionized upper tract stone management and resulted in a considerable decline in open surgical procedures. Originally described by Goodwin et al. in 1955 [7 ], PCNL was first performed by Fernstrom and Johansson in 1976 [8 ] but only gained worldwide popularity in the early 1980s with the development of more effective nephroscopes and ultrasonic lithotriptors [9 ]. The procedure was first introduced to Australia in 1982 at the Royal Melbourne Hospital [10 ]. Although PCNL remains the treatment of choice for large kidney stones, its use with smaller stones diminished considerably with the introduction of SWL. Initially developed by Chaussy et al. [11 ] in 1980 by applying aerospace technology, SWL was first performed in Britain in 1984 and then Australia in 1986 [9,12 ]. The non-invasive nature of SWL compared with open and percutaneous surgery had huge appeal, at a time when ureteroscopic equipment was still evolving. In fact, the biggest factor preventing higher usage of SWL in Australia during this time is likely to have been geographical, due to the vast distance between patients and the major centres where lithotripsy units were located [9 ]. By 1987 there were still only three lithotriptors in Australia, all confined to the southeastern seaboard. These social and logistic barriers were expressed in government health reports, which found a significant discrepancy in the use of SWL between patients from urban and rural areas [13 ], and this was eventually addressed by the establishment of mobile lithotriptor units. Diffusion of the technology was also enhanced by the provision for a Medicare rebate and reduction in the capital cost of second generation lithotriptors. Although already in use worldwide in the late 1970s, ureteroscopy was only popularized in Australia in the late 1980s following refinements in the calibre of the telescope and energy sources for intracorporeal lithotripsy [9 ]. Ureteroscopes and their paraphernalia have continued to evolve and this study demonstrates their increasing popularity over the past decade. This technological refinement probably underpins the increased rate of intervention demonstrated in our results, with the proportion of patients presenting with renal colic and undergoing intervention increasing from 40% to 47% between and Our analysis of the Medicare Australia and AIHW databases illustrates the changes in stone management in Australia since the mid-1990s with a significant increase in endoscopic interventions, steady levels of SWL and declining use of more invasive percutaneous and open procedures. Although the number of SWL procedures has remained static, its use as a proportion of total interventions has fallen considerably. It is interesting to compare management data from AIHW (nearly all public and private hospitals) and Medicare (private hospitals mostly, plus private patients in public hospitals). In , over 60% of endoscopic procedures performed overall were performed in private hospitals. This may be a result of differences in access to more sophisticated endoscopic equipment and in particular lasers, which had very limited availability in public hospitals until recently [14 ]. The expansion of emergency departments into private hospitals, resulting in a proportion of patients attending for primary treatment in an appropriately equipped hospital, may have also contributed to this increase. The total number of annual stone procedures has increased significantly over the past 15 years. The billing of more than one item number is not uncommon during endoscopic stone procedures, as patients may have ureteric and renal stones treated in the same operation. Our database does not distinguish the effect of multiple procedures in one patient, but certainly this could impact on the total number of endoscopic procedures presented in our paper. However, this does not explain the continuation of this trend from 2003 to the present. 31

4 LEE and BARIOL The increase in overall, and particularly endoscopic, stone treatments could indicate an increased prevalence of stone disease. The incidence of renal colic appears unchanged in AIHW data from 1 to We postulate that this higher prevalence may be a result of increased detection through the widespread use of CT scanning, which is highly sensitive for identifying kidney stones, although this cannot be proven from our data alone. The improved resolution of CT imaging and greater potential for incidental detection of kidney stones may have brought about a downward stage migration of sorts, facilitating an increase in minimally invasive stone treatments. The indications for treatment of kidney stones have not changed in the last 15 years; however, it is possible that as treatments have become less invasive they are easier to justify, both in patients who may have been considered suitable for conservative non-operative management as well as in asymptomatic individuals. Whilst the intervention threshold may have reduced, this is likely to be offset by a reduced overall treatment time. Patients presenting for emergency stone treatment may have longer hospitalization, longer duration of stenting and longer time off work than those managed electively [14 ]. Certainly the opportunity to treat renal calculi at the time of endoscopic removal of symptomatic ureteric stones is a unique consequence of refinement in endoscopic equipment and technique and the availability of a flexible energy source (laser). This would appear to be a reasonable approach based on the risk of renal calculi becoming symptomatic. Numerous studies have attempted to evaluate the natural history of renal stones. Hubner et al. [15 ] reviewed 63 patients with renal stones over 7 years and found that 40% required surgical intervention whilst over half experienced at least one episode of pain. Glowacki et al. [16 ] followed 107 patients with asymptomatic stones and reported a 48.5% probability of a symptomatic episode within 5 years. Although these findings support the prophylactic treatment of stones, a more recent prospective randomized control study by Keeley et al. [ 17 ] of 228 patients followed over a mean of 2.2 years revealed no significant benefit for patients managed with SWL for asymptomatic stones compared with conservative treatment in terms of quality of life, risk of symptomatic episodes, renal function or stone-free rate. These conflicting studies highlight the need for longer-term follow-up of patients before a consensus on the utility of prophylactic stone treatment can be reached. Finally, the increased number of endoscopic stone management procedures annually may be a result of higher retreatment rates, although this cannot be confirmed by our data. Despite its declining popularity in Australia, PCNL was reported in the Cochrane reports to have a higher success rate and lower retreatment rate compared with both SWL and pyeloscopy. No differences in complication rates were noted and only in the outcomes of procedural time and length of hospital stay did PCNL compare unfavourably [18 ]. This is supported by a study in Western Australia in the last decade on treatment patterns for primary urolithiasis, which found a significant sudden increase in 1991 of short-term procedural readmissions for patients presenting with stone disease, corresponding to when SWL was introduced to that state [19 ]. Comparing SWL and endoscopic procedures, although there was marked heterogeneity in the equipment used for stone management in both groups, a Cochrane meta-analysis of the stone-free rate revealed a small but significant difference favouring ureterosopy (relative risk 0.83, 95% CI ) [2 ]. Despite the limitations in data available for a comprehensive analysis of changing stone management practices in Australia, obvious trends have emerged showing an increase in overall interventions and a preference for endoscopic procedures in the treatment of upper urinary tract stones. Additional studies are necessary to determine whether this higher rate of intervention is a result of the increased prevalence or detection of stone disease, higher retreatment rates or a change in the indications for operative management. ACKNOWLEDGEMENTS The authors would like to acknowledge the administrative staff at Medicare Australia and AIHW for their assistance. CONFLICT OF INTEREST None declared. REFERENCES 1 Young JG, Keeley FX Jr. Indications for surgical removal, including asymptomatic stones. In Rao NP, Preminger GM, Kavanagh JP eds, Urinary Tract Stone Disease, Chapt 38. London : Springer, : Nabi G, Downey P, Keeley F, Watson G, McClinton S. Extra-corporeal shock wave lithotripsy (ESWL) versus ureteroscopic management for ureteric calculi. Cochrane Database Syst Rev 2007 ; 1 : CD Medicare Australia. Medicare Item Reports, Canberra, Available at statistics/mbs_item.shtml. Accessed May 4 Australian Institute of Health and Welfare. Australian Hospital Statistics 2007, Canberra, Data cube, available at procedures-data-cubes. Accessed May 5 Australian Bureau of Statistics. Australian Social Trends, Available from abs@.nsf./2f762f aeca25706c0 0834efa/e2f62e625b7855bfca2570ec007 3cdf6!OpenDocument. Accessed May 6 Australian Bureau of Statistics. Australian Demographic Statistics, Available at ausstats/abs@.nsf/mf/ Accessed May 7 Goodwin WE, Casey WC, Woolf W. Percutaneous trocar (needle) nephrostomy in hydronephrosis. JAMA 1955 ; 157 : Fernstrom I, Johansson B. Percutaneous pyelolithotomy. A new extraction technique. Scand J Urol Nephrol 1976 ; 10 : Hirsch, NA. Diffusion of new technologies to treat renal stones in Australia. Aust J Pub Health 1993 ; 17 : Nunn IN, Hare WSC. Percutaneous ultrasonic disintegration and removal of renal calculi. Med J Aust 1985 ; 142 : Chaussy C, Brendel W, Schmiedt E. 32

5 EVOLUTION OF STONE MANAGEMENT IN AUSTRALIA Extracorporeally induced destruction of kidney stones by shock waves. Lancet 1980 ; 2 : Wickham, JEA, Webb DR, Payne SR, Kellet MJ, Watkinson G, Whitfield HN. Extracorporeal shockwave lithotripsy: the first 50 patients treated in Britain. BMJ 1985 ; 290 : Australian Health Technology Advisory Committee. (1991 ). Renal Stone Therapy. Canberra : Australian Institute of Health 14 McNeill F, McNeill J, Brooks AJ. Management of kidney stone disease in New South Wales: an observational study. Med J Aust 2008 ; 189 : Hubner WA, Irby P, Stoller ML. Natural history and current concepts on the treatment of small ureteral calculi. Eur Urol 1993 ; 24 : Glowacki LS, Beecroft ML, Cook RJ, Pahl D, Churchill DN. The natural history of urinary lithiasis. J Urol 1992 ; 147 : Keeley FX Jr, Tilling K, Elves A, Menezes P, Wills M, Rao N, Feneley R. Preliminary results of a randomized controlled trial of prophylactic shock wave lithotripsy for small asymptomatic renal calyceal stones. BJU Int 2001 ; 87 : Srisubat A, Potisat S, Lojanapiwat B, Setthawong V, Laopaiboon M. Extracorporeal shock wave lithotripsy (ESWL) versus percutaneous nephrolithotomy (PCNL) or retrograde intrarenal surgery (RIRS) for kidney stones. Cochrane Database Syst Rev 2009 ; 4 : CD Holman CD, Wisniewski ZS, Semmens JB, Bass AJ. Changing treatments for primary urolithiasis: impact on services and renal preservation in 16,679 patients in Western Australia. BJU Int 2002 ; 90 : 7 15 Correspondence: Simon Bariol, Westmead Hospital Urology, PO Box 533, Wentworthville, Sydney, NSW 2145, Australia. bariols@bigpond.net.au Abbreviations : SWL, shock wave lithotripsy ; AIHW, Australian Institute of Health and Welfare ; PCNL, percutaneous nephrolithotomy. 33