Quantitative phase analysis and microstructural characterization of urinary tract calculi with X-ray diffraction Rietveld analysis on a Caribbean island

In the twin-island state of Trinidad and Tobago, urinary stone analysis is not routinely performed. This study investigates, via powder X-ray diffraction, 52 urinary tract calculi collected from hospitals in Trinidad. Of these, 46 stones were analysed with Rietveld refinement for quantitative analysis and materials characterization. Refined unit-cell, microstructural and weight fraction parameters were obtained, with the last being used for stone classification. The results revealed seven distinct mineralogical phases of varying frequency: calcium oxalate monohydrate (COM, 58%), calcium oxalate dihydrate (COD, 23%), carbonated apatite (APA, 48%), brushite (BRU, 6%), struvite (STR, 42%), uric acid (UA, 23%) and ammonium acid urate (AAU, 19%). The average refined crystallite sizes were 1352 ± 90 Å (COM), 1921 ± 285 Å (COD), 83 ± 5 Å (APA), 1172 ± 9 Å (BRU), 1843 ± 138 Å (STR), 981 ± 87 Å (UA) and 292 ± 83 Å (AAU). Subsequently, 36.5% of stones were categorized as phosphates, 34.6% as oxalates, 13.5% as uric acid/urates and 15.4% as mixed compositions. The study findings highlight the importance of stone analysis as a necessary step towards disease management of local patients, and endorse the application of Rietveld refinement as a natural extension to diffraction-based kidney stone investigations.

Stone composition of renal stone formers from different global regions

Objective: To study urinary stone composition patterns in different populations around the world. Materials and methods: Data were collected by reviewing charts of 1204 adult patients of 10 countries with renal or ureteral stones (> 18 years) in whom a stone analysis was done and available. Any method of stone analysis was accepted, but the methodology had to be registered. Results: In total, we observed 710 (59%) patients with calcium oxalate, 31 (1%) with calcium phosphate, 161 (13%) with mixed calcium oxalate/calcium phosphate, 15 (1%) with carbapatite, 110 (9%) with uric acid, 7 (< 1%) with urate (ammonium or sodium), 100 (9%) with mixed with uric acid/ calcium oxalate, 56 (5%) with struvite and 14 (1%) with cystine stones. Calciumcontaining stones were the most common in all countries ranging from 43 to 91%. Oxalate stones were more common than phosphate or mixed phosphate/oxalate stones in most countries except Egypt and India. The rate of uric acid containing stones ranged from 4 to 34%, being higher in Egypt, India, Pakistan, Iraq, Poland and Bulgaria. Struvite stones occurred in less than 5% in all countries except India (23%) and Pakistan (16%). Cystine stones occurred in 1% of cases. Conclusions: The frequency of different types of urinary stones varies from country to country. Calcium-containing stones are prevalent in all countries. The frequency of uric acid containing stones seems to depend mainly on climatic factors, being higher in countries with desert or tropical climates. Dietary patterns can also lead to an increase in the frequency of uric acid containing stones in association with high obesity rates. Struvite stones are decreasing in most countries due to improved health conditions.

Endoscopic Papillary Abnormalities and Stone Recognition (EPSR) during Flexible Ureteroscopy: A Comprehensive Review

Introduction: The increasing efficiency of the different lasers and the improved performance of endoscopic devices have led to smaller stone fragments that impact the accuracy of microscopic evaluation (morphological and infrared). Before the stone destruction, the urologist has the opportunity to analyze the stone and the papillary abnormalities endoscopically (endoscopic papillary recognition (EPR) and endoscopic stone recognition (ESR)). Our objective was to evaluate the value for those endoscopic descriptions. Methods: The MEDLINE and EMBASE databases were searched in February 2021 for studies on endoscopic papillary recognition and endoscopic stone recognition. Results: If the ESR provided information concerning the main crystallization process, EPR provided information concerning the origin of the lithogenesis and its severity. Despite many actual limitations, those complementary descriptions could support the preventive care of the stone formers in improving the diagnosis of the lithogenesis mechanism and in identifying high-risk stone formers. Conclusion: Until the development of an Artificial Intelligence recognition, the endourologist has to learn EPSR to minimize the distortion effect of the new lasers on the stone analysis and to improve care efficiency of the stone formers patients.

The factors that affecting shockwave lithotripsy treatment outcome of kidney stones

Bacground: We aimed to analyze combination of the schockwave lithotripy (SWL) success predictors. Methods: In this retrospective study, the outcomes of the patients with kidney stones treated with SWL were analyzed. Adult patients (≥18 years) with complete records with non-contrast computed tomography (NCCT), stone analysis, laboratory data were involved in the study. Patients who were with urinary system anomalies, who were receiving alpha-blocker and/or calcium channel blockers and whom with impaired kidney function were excluded. The effect of stone density, skin-to-stone distance (SSD), perirenal tissue density (PTD), subcutaneous tissue density (STD), stone size, stone burden, stone localization, infundibulopelvic angle (IA), as well as body mass index (BMI) and stone analysis results on the success of the treatment was evaluated. Results: SSD, PTD, STD, stone localization, IA, as well as body-mass index, did not have any association with SWL success. Stone size and stone burden had a significant association with treatment success (p = 0.0001), and the cut-off values determined for stone size and stone burden were 12.95 mm (p = 0.0006) and 121.38 mm2 (p = 0.004) respectively. Stone density also had a significant association with treatment success (p = 0.0001), and the cut-off value determined for stone density was 739 HU (Hounsfield Unit) (p = 0.001). Treatment success was significantly lower in cystine and calcium oxalate monohydrate stones compared to other stone types (p = 0.019). Conclusion: Significant markers that determine SWL effectiveness are stone size, stone burden, stone density and, besides, stone type.

The first epidemiology study of urolithiasis in New Brunswick

Introduction: Understanding the compositions of a kidney stone is crucial in leading to proper treatment and in preventing reoccurring urolithiasis. This study aimed to investigate the prevalence of urolithiasis in the province of New Brunswick (NB), Canada. Methods: A total of 3828 kidney stone analysis reports from October 1, 2016 to September 30, 2019, were reviewed from laboratory information systems. Among them, 3311 were identified as new cases. Stone compositions were analyzed by the Fourier Transform Infrared spectrometry. Incident rates were compared using Chi-squared analysis of different age, sex, and regional health authority (RHA) zones. Results: The prevalence of urolithiasis in NB was 147.8 per 100 000 person-years. Males had a significantly higher (X2=254, p<0.001) incident rate of 189 (95% confidence interval [CI] 182–198) than females (107 [95% CI 102–114]) per 100 000 person-years. Zone 1 had significantly higher (245 per 100 000 person-years, p<0.001) prevalence compared to other RHA zones. Age group over 65 years had the highest incidence rate of 253 per 100 00 person-years of all groups. The predominant kidney stone types in NB were whewellite (60.68%) and weddellite (11.58%). Those patients aged 0–18 years had a high percentage of struvite (4.32%) vs. the provincial average (2.19%) (p<0.001). Conclusions: The prevalence of NB’s urolithiasis is slightly higher than that of Ontario. Since both zones 1.1 and 1.2 have significantly high prevalence and are situated in the Moncton area (combined zone 1), it may suggest that geographical factors play a role in the prevalence of urolithiasis in NB.

Gallstone Ileus Decades after Cholecystectomy and Pylorus-Preserving Whipples

We report a case of small bowel obstruction due to gallstone ileus found in a patient with previous pancreaticoduodenectomy (Whipple procedure). Investigation by computed tomography of the abdomen showed a transition point in the midjejunum due to a radioopaque intraluminal mass. Following resuscitation, the patient underwent laparotomy to remove the offending mass from the midjejunum. Subsequent stone analysis confirmed a cholesterol-rich gallstone. This is thus the first description of gallstone ileus following Whipple procedure. The rarity of this presentation and a literature review is presented.