Na L. et al., 2023: Development and validation of a predictive model for major complications after extracorporeal shockwave lithotripsy in patients with ureteral stones: based on a large prospective cohort
Na L, Li J, Pan C, Zhan Y, Bai S.
Department of Urology, Shengjing Hospital of China Medical University, 36 Sanhao Street, Shenyang, 110004, People's Republic of China.
Department of Urology, Shengjing Hospital of China Medical University, 36 Sanhao Street, Shenyang, 110004, People's Republic of China.
Department of Urology, Shengjing Hospital of China Medical University, 36 Sanhao Street, Shenyang, 110004, People's Republic of China.
Abstract
The risk factors of complications after SWL are not well characterized. Therefore, based on a large prospective cohort, we aimed to develop and validate a nomogram for predicting major complications after extracorporeal shockwave lithotripsy (SWL) in patients with ureteral stones. The development cohort included 1522 patients with ureteral stones who underwent SWL between June 2020 and August 2021 in our hospital. Five hundred and fifty-three patients with ureteral stones participated in the validation cohort from September 2020 to April 2022. The data were prospectively recorded. Backward stepwise selection was applied using the likelihood ratio test with Akaike's information criterion as the stopping rule. The efficacy of this predictive model was assessed concerning its clinical usefulness, calibration, and discrimination. Finally, 7.2% (110/1522) of patients in the development cohort and 8.7% (48/553) of those in the validation cohort suffered from major complications. We identified five predictive factors for major complications: age, gender, stone size, Hounsfield unit of stone, and hydronephrosis. This model showed good discrimination with an area under the receiver operating characteristic curves of 0.885 (0.872-0.940) and good calibration (P = 0.139). The decision curve analysis showed that the model was clinically valuable. In this large prospective cohort, we found that older age, female gender, higher Hounsfield unit, size, and grade of hydronephrosis were risk predictors of major complications after SWL. This nomogram will be helpful in preoperative risk stratification to provide individualized treatment recommendations for each patient. Furthermore, early identification and appropriate management of high-risk patients may decrease postoperative morbidity.
Urolithiasis. 2023 Mar 2;51(1):42. doi: 10.1007/s00240-023-01417-7. PMID: 36862228. FREE ARTICLE
Comments 1
This is another publication on SWL of ureteral stones by the same group (1)
The inclusion criteria are identical except that stone size was not limited to 6-20 mm (1), but to > 6mm in the present study. One would expect that consequently the cohort and the stones would be larger. However, in the present study the development and the validation cohort included 1522 and 553 patients resp. while in the first study (1) the relevant numbers were 1698 and 712. In fact, the stones were slightly smaller in the present study! Obviously, patients were selected but there is no hint on the selection bias in the manuscripts. Other than, in the first study here are some details on the lithotripter: “11 cm served as the focal depth, 7 mm served as the focus area, 45–50 mm served as the focal area, and 6–30 MPa served as the focal pressure.”
Now there are two nice studies with scoring systems on the success (1) and complications of SWL of ureteral stones. Why will they not make it into the standards of SWL therapy? I will ask Hans-Göran Tiselius and Christian Chaussy for comments and answers.
1 Yin X, et al. Development and validation of a predictive model for stone-free failure after extracorporeal shockwave lithotripsy in patients with ureteral stone in a large prospective cohort.
World J Urol. 2023 Mar 13. doi: 10.1007/s00345-023-04358-3. PMID: 36912972
Peter Alken