TAIPEI, TAIWAN (UroToday.com) - Introduction and Objectives: The Triple D (DDD) score utilizes CT findings to predict the probability of shockwave lithotripsy (SWL) success. A recent cost-effectiveness analysis reported that SWL outperforms URS when the SWL stone-free (SF) rate is greater than 65%. We hypothesize that many patients undergoing URS with a favorable DDD score may have been excellent SWL candidates.
Methods: The last 100 patients undergoing URS at our institution were reviewed. 75 had available preoperative CT imaging. Patients with distal ureteral stones, acute presentation, or multiple stones larger than 4 mm on the side of treatment were excluded. DDD score was calculated from stone density, volume and skin-to-stone distance.
Results: 61 patients were included. 29/61 (47.5%) of patients had a DDD score greater than or equal to 2. Among these, 22/61 (36.0%) patients had a DDD score of 2 and 7/61 (11.4%) had a DDD score of 3, which correlate with SWL SF rates of 75% and 95%, respectively. The overall URS SF rate for our cohort was 92%. 66% of patients that failed initial treatment had multiple stones and the remaining 33% had stone volume greater than 500 mm3.
Conclusions: Cost-effective stone treatment requires careful patient selection. The DDD score identifies patients with a high probability for successful SWL. We conclude that many patients undergoing URS as first line therapy would be excellent single-session SWL candidates. These findings reinforce the importance of proper patient selection, which allow for SWL to be a noninvasive and cost-effective treatment modality for the management of urinary stones.
Source of Funding: None
| Listen to an interview with Timothy Tran, one of the authors of this study. |
Presented by Timothy Tran, Andrew Leone, Simone Thavaseelan, and Gyan Pareek at the 32nd World Congress of Endourology & SWL - September 3 - 7, 2014 - Taipei, Taiwan
Alpert Medical School of Brown University, Providence, RI USA
