Hospital admission for treatment of complications after extracorporeal shock wave lithotripsy for renal stones: a study of risk factors

Risk factors of hematoma after SWL for renal calculi: analysis from RCTs and a literature review

OBJECTIVE

To identify risk factors of perinephric hematoma following extracorporeal shockwave lithotripsy (SWL) for renal calculi through combined analysis of two randomized controlled trials.

PATIENTS AND METHODS

This post-hoc analysis included adult patients with solitary renal calculi ranging from 5 to 15 mm, treated with SWL between 2016 and 2022. All patients received cross-sectional imaging (either non-contrast computer tomography scan or magnetic resonance imaging) two days post-SWL to assess the presence and severity of perinephric hematoma.

RESULTS

Among 573 patients analyzed, 173 (30.9%) developed perinephric hematoma by Day 2 post-SWL. Multivariate logistic regression identified higher total energy delivered (odds ratio [OR] = 1.533, p = 0.003), higher mean stone density (OR = 2.603, p = 0.01), higher maximal stone density (OR = 3.578, p = 0.03), and lower pole stone location (OR = 1.545, p = 0.029) were risk factors for the development of hematoma. Conversely, the stepwise ramping protocol was a protective factor for hematoma formation. (OR = 0.572, p = 0.042).

CONCLUSIONS

This study elucidates key factors influencing the risk of perinephric hematoma post-SWL, highlighting the importance of procedural adjustments such as the stepwise ramping protocol to reduce complications. These insights call for targeted patient and treatment strategy optimization to enhance SWL safety and efficacy.

Predictive markers for infections after extracorporeal shockwave lithotripsy in patients with kidney stone based on a large prospective cohort

OBJECTIVE

Infections in patients with kidney stones after extracorporeal shockwave lithotripsy (SWL) is a common clinical issue. However, the associated factors are unclear. Therefore, we aim to develop and validate a predictive model for infections after SWL in patients with kidney stone.

METHODS

Between June 2020 and May 2022, consecutive kidney stone patients were enrolled. Of them, 553 patients comprised the development cohort. One hundred sixty-five patients comprised the validation cohort. The data were prospectively collected. The stepwise selection was applied using the likelihood ratio test with Akaike's information criterion as the stopping rule; A predictive model was constructed through multivariate logistic regression. The performance was evaluated regarding discrimination, calibration, and clinical usefulness.

RESULTS

Predictors of infections after SWL in treating kidney stones included older age (OR = 1.026, p = 0.041), female (OR = 2.066, p = 0.039), higher BMI (OR = 1.072, p = 0.039), lower stone density (OR = 0.995, p < 0.001), and higher grade of hydronephrosis (OR = 5.148, p < 0.001). For the validation cohort, the model showed good discrimination with an area under the receiver operating characteristic curve of 0.839 (95% CI 0.736, 0.941) and good calibration. Decision curve analysis demonstrated that the model was also clinically useful.

CONCLUSION

This study indicated that age, gender, BMI, stone density, and hydronephrosis grade were significant predictors of infections after SWL in treating kidney stones. It provided evidence in optimizing prevention and perioperative treatment strategies to reduce the risk of infection after SWL.

Clinical use of renal point-of-care ultrasound after extracorporeal shock wave lithotripsy

Background

Extracorporeal shock wave lithotripsy is widely used to treat symptomatic nephrolithiasis. Complications of this procedure can occur and point-of-care ultrasound can help to diagnose and manage some of these cases.

Case presentation

A 61-year-old man was admitted to the hospital with intense right lumbar pain 24 h after being submitted to a extracorporeal shock wave lithotripsy. Bedside ultrasound showed a hyperechoic subcapsular lesion along the right kidney. This finding, along with the clinical examination, suggested the diagnosis of subcapsular renal hematoma. The patient was managed conservatively with clinical and ultrasound reassessments.

Conclusions

This case shows the use of bedside ultrasound to diagnose a subcapsular renal hematoma as a complication of extracorporeal shock wave lithotripsy. However, the sensitivity is low and other image methods can be necessary to make the diagnosis.

Influence of acetylsalicylic acid and low-molecular weight heparins on the formation of renal hematoma after shock wave lithotripsy

PURPOSE

To investigate the risk of renal hematoma (RHT) after shock wave lithotripsy (SWL) among patients on acetylsalicylic acid (ASA) or low-molecular-weight heparin (LMWH).

PATIENTS AND METHODS

Retrospective analysis of 434 patients treated with SWL for nephrolithiasis and ureterolithiasis of the proximal ureter. Primary endpoint was detection of RHT by ultrasound the day after SWL. Secondary outcome variables included transfusion of erythrocyte concentrate(s), interventions, hospital readmission or death due to RHT within 30 days of SWL. Binary logistic regression analysis was used including a post hoc one-way analysis.

RESULTS

Of 434 patients, 33 (7.6%) and 67 (15.4%) patients were medicated with ASA and LMWH, respectively. RHT was detected in 20 of 434 (4.6%) patients. Of those, 3 (20%) were on ASA, 6 (35%) were on LMWH, 1 (5%) was on ASA and LMWH, and 10 (50%) had no anticoagulation. Univariate analysis showed a statistically significant higher risk for RHT among patients on ASA (p = 0.04) and LWMH (p = 0.02) with an untreated urinary tract infection (UTI) (p = 0.008) and history of cardiovascular disease (p = 0.028). On multivariate analysis, ASA medication, untreated UTI (OR 4.4, 95% CI 1.31-14.75, p = 0.016 and OR 5.79, 95% CI 1.65-20.32, p = 0.03) and a therapeutic dose of LMWH (OR 10.4, 95% CI 1.74-62.27, p = 0.01) were independent predictors for RHT.

CONCLUSIONS

Before SWL, a patient risk profile should be evaluated. If feasible, LMWH in therapeutic dosing should be avoided, and ASA should be discontinued. UTI should be treated before SWL in any case.

TRIAL REGISTRATION

http://www.clinicaltrials.gov ; Identifier NCT02875717.