A Simple Objective Method to Assess the Radiopacity of Urinary Calculi and its Use to Predict Extracorporeal Shock Wave Lithotripsy Outcomes

Role of Noncontrast Computed Tomography Parameters in Predicting the Outcome of Extracorporeal Shock Wave Lithotripsy for Upper Urinary Stones Cases: A Meta-analysis

RATIONALE

Extracorporeal shock wave lithotripsy (ESWL) is widely considered the primary approach for managing urinary tract stones. This study aimed to assess the predictive factors associated with non-contrast computed tomography (NCCT)-based parameters of upper urinary stones in relation to the outcomes of ESWL.

MATERIALS AND METHODS

A systematic search was conducted in PubMed, ScienceDirect, Web of Science, and Cochrane Library to identify all relevant studies published up to June 3, 2023. Several NCCT-based parameters to predict ESWL outcomes, comprised of mean stone density (MSD), skin-to-stone distance (SSD), and stone size, were extracted and analyzed using Review Manager software.

RESULTS

Out of 979 publications screened, a total of 39 publications, involving 7869 patients, were enrolled in the analysis. The pooled estimate demonstrated significant differences between MSD, and stone size between successful and failure of stone fragmentation groups, in which lower values of these parameters are associated with successful ESWL outcomes.

CONCLUSION

The results from the current study suggested that lower NCCT parameters, notably MSD, SSD, and stone size, are significantly associated with successful ESWL outcome. However, additional large-scale prospective studies are required to utilize these parameters effectively, and the optimal cutoff value should be determined.

Three-dimensional mean stone density on non-contrast computed tomography can predict ureteroscopic lithotripsy outcome in ureteral stone cases

The association between mean stone density (MSD) and ureteroscopic lithotripsy outcome remains controversial. MSD automatically measured by 3D images of stones (3D-MSD) was recently reported to be more useful than manual measuring methods for predicting outcomes of shock-wave lithotripsy. This study aims to investigate whether 3D-MSD can predict ureteroscopic lithotripsy outcome. We retrospectively identified 218 patients who underwent ureteroscopic lithotripsy for kidney stones (n = 135) and ureteral stones (n = 83) between February 2011 and April 2017 with pretreatment non-contrast computed tomography (NCCT) at our hospital. Stone volume and 3D-MSD were automatically measured using high functional viewer. Logistic regression analysis was performed to identify factors contributing to treatment failure. Treatment failure was determined as residual fragments ≥ 4 mm using NCCT within 3 months after operation. Treatment failure rate was 20.1% (44/218 cases). Patients in treatment failure group had higher percentage of kidney stones (< 0.01) and multiple stones (p < 0.01), larger stone volume (p < 0.01) and higher 3D-MSD (p < 0.01). Multivariate analysis revealed that stone location (p < 0.01), stone number (p < 0.01), stone volume (p = 0.02) and 3D-MSD (p = 0.02) independently predicted the outcome. Categorized by stone location, 3D-MSD was the only significant independent predictor in cases of ureteral stones (p < 0.01), but was not significant in cases of kidney stones. 3D-MSD is useful for predicting ureteroscopic lithotripsy outcome in cases of ureteral stones.

Noncontrast Computed Tomography Parameters for Predicting Shock Wave Lithotripsy Outcome in Upper Urinary Tract Stone Cases

Kidney stones are a major public health concern with continuously increasing worldwide prevalence. Shock wave lithotripsy (SWL) is the first line treatment choice for upper urinary tract calculi with ureteroscopy and has advantages of safety and noninvasiveness, but the treatment success rate of SWL is lower than that of other therapies. It is therefore important to identify predictive factors for SWL outcome and select a suitable treatment choice for patients with upper urinary tract calculi. In recent years, computed tomography (CT) has become the gold standard for diagnosis of upper urinary tract calculi. Several factors based on CT images, including skin-to-stone distance, mean stone density, stone heterogeneity index, and variation coefficient of stone density, have been reported to be useful for predicting SWL outcome. In addition, a new method of analysis, CT texture analysis, is reportedly useful for predicting SWL outcomes. This review aims to summarize CT parameters for predicting the outcome of shock wave lithotripsy in stone cases in the upper urinary tract.

The efficacy of radiographic anatomical measurement methods in predicting success after extracorporeal shockwave lithotripsy for lower pole kidney stones

OBJECTIVES

To assess the impact of lower pole calyceal anatomy on clearace of lower pole stones after extracorporeal shockwave lithotripsy (ESWL) by means of a new and previously defined radiographic measurement method.

MATERIALS AND METHODS

Sixty-four patients with solitary radiopaque lower pole kidney stones were enrolled in the study. Infundibulopelvic angle (IPA), infundibulotransverse angle (ITA), infundibular lenght(IL), and infundibular width (IW) were measured on the intravenous urographies which were taken before the procedure.

RESULTS

48 of 64 patients (75%) were stone-free after a follow-up period of 3 months. The IPA,ITA,IL and IW were determined as statistically significant factors, while age,gender and stone area were found to have no impact on clearance.

CONCLUSION

By the help of radiographic measurement methods related to lower pole kidney anatomy, appropriate patient selection and increment in success after ESWL may be achieved.

Prediction of the energy required for extracorporeal shock wave lithotripsy of certain stones composition using simple radiology and computerized axial tomography

OBJECTIVE

To demonstrate that urinary lithiasis have a specific susceptibility to fracture through extracorporeal shock wave lithotripsy (ESWL), which is common for all calculi with the same composition and which can be estimated before treatment using CT or plain x-ray.

MATERIAL AND METHOD

We present an in vitro, prospective, randomized, blind and multi-centre study involving 308 urinary calculi. 193 of these met the inclusion criteria: whole calculi composed purely of calcium oxalate monohydrate (COM), uric acid (UA) or carbonate apatite (CA), or a mix of oxalate (COMix) and of a size greater than 0.5 cm. The samples were broken using lithotripsy until reaching a pre-established level of comminution. The variables employed were energy dose (Edose) per cm(3) of lithiasis and Edose adjusted to lithiasic surface (EdAJ) per cm(3).

RESULTS

COM was the hardest, requiring an Edose of 119,624 mJ/cm(3) and an EdAJ of 36,983 mJ/cm(3), followed by COMix (75,501/36,983), CA (22,734/21,186) and UA (22,580/6,837) (P < .05). Gmax y Gmda were correlated with Edose (r = 0.434/r = 0.420) and EdAJ (r = 0.599/r = 0.545) (P < .01). UH were correlated, in bone window and soft tissue window, with Edose/cm(3) (r = 0.478/r = 0.539) y EdAJ/cm(3) (r = 0.745/r = 0.758) (P < .01).

CONCLUSIONS

In our in vitro research lithiasis require, due to the specific nature of their composition, a given amount of energy in order to be broken by ESWL, which is inherent to all those sharing the same composition, and can be predicted using CT or plain x-ray.