Chan LH et al, 2017: Primary SWL Is an Efficient and Cost-Effective Treatment for Lower Pole Renal Stones Between 10 and 20 mm in Size: A Large Single Center Study.
Chan LH, Good DW, Laing K, Phipps S, Thomas BG, Keanie JY, Tolley DA, Cutress ML.
Department of Urology, The Scottish Lithotriptor Centre, Western General Hospital, NHS Lothian, Edinburgh, Scotland.
Abstract
INTRODUCTION: To assess the clinical features, outcomes, complications, and cost-effectiveness of shockwave lithotripsy (SWL), flexible ureterorenoscopy (FURS), and percutaneous nephrolithotomy (PCNL) in the treatment of lower pole (LP) stones (10-20 mm) in a large tertiary referral center.
PATIENTS AND METHODS: Consecutive patients treated for solitary LP stones (10-20 mm) between 2008 and 2013 were identified from a prospective database. SWL was used as primary treatment in all cases (following a stone multidisciplinary team assessment), with FURS and PCNL reserved for SWL contraindications, failure, or patient choice. "Success" was defined as stone free and/or clinically insignificant stone fragments (≤3 mm) at 1 and 3 months follow-up. Effect of anatomy on SWL success was determined from using CT images and regression analysis. Average cost per treatment modality (including additional second-line treatments) was calculated for each group using the National Health Service England 2014/15 National Tariff Healthcare Resource Group codes.
RESULTS: Two hundred twenty-five patients were included (mean age 54.9; median stone size 12 mm). One hundred ninety-eight (88%), 21 (9.3%), and 6 (2.7%) patients underwent SWL, FURS, and PCNL as primary treatments, respectively, for median stone sizes of 12, 12, and 20 mm. Overall success rates were 82.8%, 76.1%, and 66.7%, respectively (p < 0.05). Sixty-three percent of patients undergoing primary SWL were effectively treated after one session. Anatomical analysis determined infundibulopelvic angle and infundibular length to be significantly different in patients effectively treated with SWL (p = 0.04). The average cost per treatment modality was also significantly lower for SWL (£750) than for FURS (£1261) or PCNL (£2658) (p < 0.01).
CONCLUSION: SWL is both an efficacious and cost-effective primary treatment for patients with solitary LP stones (10-20 mm). The majority of patients can be effectively treated with primary SWL in a dedicated stone center, with the benefits of a short length of stay, low complication, and auxiliary treatment rates. The referral of such patients to high-volume lithotripsy centers with demonstrable outcomes should be given due consideration.
J Endourol. 2017 Mar 29. doi: 10.1089/end.2016.0825. [Epub ahead of print]
Comments 1
At a time when the advantages of RIRS and PCNL are repeatedly emphasized in the literature and at various stone conferences, the results presented in this study deserve serious consideration.
The authors used SWL as the primary procedure for stone treatment when patients with contraindications to this technique were excluded. The current report shows the results obtained with stones located in the lower calyces and with a largest diameter in the range of 10-20 mm.
When the cost of health care continuously is escalating it is reassuring to note that for the 225 patients subjected to SWL successful treatment (stone-free or with minimal fragments ≤ 3 mm) was recorded in as many as 83%! Moreover, the treatments were carried out in an out-patient setting with only analgesics, with a lower rate of complications than in patients treated with FURS or PCNL and at a much lower cost.
Reported cost for SWL, RIRS and PNL:
COST
SWL £ 750
FURS £ 1261
PCNL £ 2658
It is of particular note that success after one single treatment was recorded in 63%. The average number of treatments was 1.24 (calculated form the data).
It is obvious that the authors have used their cumulated experience and expertise to complete SWL in an optimal way, a factor that is of fundamental importance for successful outcome.
There are some other interesting observations:
The anatomy of the lower calyx system apparently was less important than generally believed. In terms of stone-free outcome the measured variables (IPA, IL and IV) there was no significant difference between those rendered stone-free and those not.
The bottom-line of this report is that to maintain a non-invasive out-patient procedure for stone removal with lowest possible rate of complications and lowest cost, SWL still is an excellent choice. This report is worthwhile reading for all those who care about patients and the health economy, rather than giving preference the most recent endoscopic technical achievements.