Spectrum of urinary stone composition in Northwestern Rajasthan using Fourier transform infrared spectroscopy

Predictive factors for functional improvement and assessment of outcomes in CKD patients after PCNL

INTRODUCTION

Patients with urinary stone disease may present with CKD. The incidence of developing end stage renal disease (ESRD) in patients with renal calculi is 0.2%-3.2%. In the present study we aim to discuss outcomes of PCNL in CKD patients.

MATERIALS AND METHODS

This was a prospective observational study done, from January 2023 to March 2024. Data of 96 CKD patients with renal stones who underwent standard PCNL were recorded. Patients were followed up with urinalysis, serum creatinine and ultrasound KUB. Preoperative eGFR were compared with eGFR 36 months follow up. Patients were divided into two groups. Group 1- improved and group 2- stable or worsened disease since the final follow up visit.

OBSERVATIONS AND RESULTS

After PCNL renal function improvement was seen in 52 (54%) patients that is, Group I & in 44 (46%) patients it was stable or declined that is, Group II. In Group I, mean preoperative eGFR was 41.13 ± 14.23 ml/min/m2 which improved to 46.91 ± 12.14. In Group II mean preoperative eGFR was 37.14 ± 12.32 which declined to 33.17 ± 12.57. The statistically significant factor decreasing the efficacy of PCNL in CKD patients were presence of co morbidities (Hypertension, DM; p = 0.007), staghorn stones (p = 0.001), history of previous renal surgery (p = 0.001), operation time > 100 min (p < 0.0001), post PCNL stone free status(p < 0.0001), and Complications(p = 0.03). After 6 months follow up 8 patients in Group I shifted from CKD stage 4 to CKD stage 3 and four patients in group II shifted from CKD stage 3 to CKD stage 4.

CONCLUSION

Factors like presence of comorbidities, staghorn calculus, previous surgery operative time and post operative complications affects improvement of renal function in CKD patients after stone clearance.

The not so 'simple' laparoscopic nephrectomy: Experience with 3D laparoscopy from a tertiary care centre

INTRODUCTION

Laparoscopic simple nephrectomy (LSNx) is among the gold standard options for management of selected poorly functioning and most non-functioning kidneys (PFK/NFKs). Our objective was to audit our patients who had undergone LSNx for benign causes and assess their perioperative outcomes and analyse the factors correlating with these outcomes.

MATERIALS AND METHODS

We reviewed our prospectively collected data of patients with PFK/NFKs due to benign causes who underwent a LSNx on a three-dimensional (3D) system via a transperitoneal approach between January 2017 and June 2023. Details on clinical profile, radiological findings and peri-operative details were recorded and analysed.

RESULTS

A total of 302 patients underwent LSNx in the study duration. Urolithiasis was the most common cause of PFK/NFKs in 66.5% of patients followed by pelvi-ureteric junction obstruction in 14.9%. Rate of conversion to open surgery was 5.3%. Final histopathology revealed chronic pyelonephritis in 82% patients and Xanthogranulomatous pyelonephritis (XGPN) in 14%. Multivariate analysis revealed presence of pre-operative fat stranding on imaging, larger kidney size, presence of XGPN and pyonephrosis to be significantly associated with longer operation times. Prior renal surgery, positive urine culture, presence of XGPN and a higher body mass index was associated with a longer hospital stay and increased rate of post-operative complications.

CONCLUSION

LSNx is commonly employed for management of PFK/NFKs from various aetiologies, the most common of which is urolithiasis in our experience. Multiple clinico-radiological factors as described correlated with longer operative times and prolonged hospital stay, which aids in surgical planning and patient counselling.

Retrospective analysis of urinary tract stone composition in a Chinese ethnic minority colony based on Fourier transform infrared spectroscopy

To analyze the relationship between the composition of urinary stones and various influencing factors in the Enshi region. We used FT-IR to examine the composition of 1092 stone samples. Combined with the relevant clinical materials, the data were analyzed using both one-dimensional statistical methods and multivariate statistical methods. The study included 1092 stone samples, classified as follows: 457 (41.8%) with a single component, 453 (41.5%) with two components, 149 (13.6%) with three components, and 33 (3.0%) with four components. Stones were categorized into five types: Calcium Oxalate (CaOx) (76.4%), carbapatite (CaP) (9.3%), Struvite (ST) (8.3%), Uric Acid (UA) (4.9%), and Others (1.0%). Age, gender, urinary tract infection (UTI), family history of urinary stones (FH), hyperuricemia (HUA) and stone location were significantly associated with stone type. Logistic regression revealed that females and UTI were relative risk factors for predicting CaP and ST, while FH and HUA were relative risk factors for predicting UA. Our study indicates that the overall composition of urinary tract stones in the Enshi region is consistent with that of the entire China. Additionally, the predisposing factors for stone formation vary in terms of gender, age, FH, UTI, hyperuricemia HUA, and stone location.

Machine learning based multi-label classification of single or mixed-composition urinary stones in in vivo spectral CT

BACKGROUND

Urinary stones comprise both single and mixed compositions. Knowledge of the stone composition helps the urologists choose appropriate medical interventions for patients. The parameters from the spectral computerized tomography (CT) analysis have potential values for identification of the urinary stone compositions.

PURPOSE

The present study aims to identify the compositions of urinary stones in vivo using parameters from spectral CT and machine learning, based on multi-label classification modeling.

METHODS

This retrospective study collected 252 urinary stone samples with single/mixed compositions (including carbapatite [CP], calcium oxalate monohydrate [COM], calcium oxalate dehydrate [COD], uric acid [UA], and struvite [STR]), which were confirmed by ex vivo infrared spectroscopy. Parameters were extracted from an energy spectrum analysis (ESA) of the spectral CT, including the effective atomic number (Z_eff ), Z_eff histogram, CT values at a given x-ray energy level, and material densities. These ESA parameters were utilized for composition analysis via a multi-label classification fusion framework, where 250 multi-label models were built and the classification decisions from the top performance models were integrated by a multi-criterion weighted fusion (MCWF) approach in order to reach a consensus prediction. An example-based metric A c c e x a m $Ac{c_{exam}}$ and label-based metric A c c l a b e l $Ac{c_{label}}$ were used for global and label-wise accuracy evaluations, respectively. The top-ranked parameters associated with discriminating the stone composition were also identified.

RESULTS

The multi-label classification fusion framework achieved an overall A c c e x a m $Ac{c_{exam}}$ of 81.2%, with A c c l a b e l $Ac{c_{label}}$ of 86.7% (CP), 90.6% (COM), 80.6% (COD), 95.0% (UA), and 94.4% (STR) for each composition on the independent testing cohort 1, and A c c e x a m $Ac{c_{exam}}$ of 76.4% with A c c l a b e l $Ac{c_{label}}$ of 80.5% (CP), 88.7% (COM), 74.9% (COD), 94.4% (UA), and 98.5% (STR) on the independent testing cohort 2.

CONCLUSION

The parameters extracted from the ESA on spectral CT can be utilized to characterize single or mixed stone compositions via multi-label classification modeling. The generalization capability of the proposed methodology still requires further verification.

Renal vein injury during percutaneous nephrolithotomy: A surgical catastrophe - Management and lessons learned

Percutaneous nephrolithotomy (PCNL) is the treatment of choice for large and complex renal calculi. We encountered a patient who was planned for PCNL in a peripheral hospital, without a preoperative computed tomography scan but was abandoned during tract dilatation due to intractable bleeding and was referred to our institute with nephrostomy in situ in a clamped state. After evaluation, the tip of the nephrostomy tube was found to be in the left renal vein causing secondary thrombosis. Due to the nonfunctional status of the kidney in the dynamic scan, the patient underwent laparoscopic left simple nephrectomy with thrombectomy without any major intraoperative complication and was discharged in stable condition.

The Associations Between Tea and Coffee Drinking and Risk of Calcium-Oxalate Renal Stones

Findings regarding the association between tea and coffee consumption and oxalate-calcium stone are sparse and uncertain. The purpose of this study was to investigate the relations of tea and coffee with the risk of calcium oxalate stone formation. A total sample of 215 newly diagnosed patients with calcium oxalate stones and 215 controls matched for sex and age were recruited. Dietary intake of participants was assessed using a validated food frequency questionnaire over the preceding year and participants were asked to determine how many glasses of tea and cups of coffee they usually use. The associations between tea and coffee and kidney stone were examined using multivariable logistic regression. Compared with controls, cases had greater intake of tea (2.18±0.76 vs. 1.82±0.79 glasses/d) but lower intake of coffee (1.18±0.38 vs. 1.26±0.44 cups/week). After adjustment for potential confounders, compared with those who drank <2 glasses of tea/d, individuals with tea consumption of ≥4 glasses/d had greater risk for having calcium oxalate stone (OR= 2.73; 95 % CI: 1.50, 4.99). In the crude model, compared with coffee consumption for <1 cup/week, consumption of ≥1 cup/week was associated with a 38 % decrease in the risk of calcium oxalate stone. However, adjustment for potential confounders disappeared the significance (OR=0.81; 95 % CI: 0.48, 1.35). These results suggest that while high consumption of tea is associated with increased risk of calcium oxalate kidney stone, coffee drinking is not pertinent. However, due to low consumption of coffee in this population, our results should be interpreted cautiously.

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.

A 13 year hospital based study on the Trend of Urinary Stone Disease in Uttarakhand, India

Background

The present retrospective study on urinary stone disease in the Uttarakhand state was necessitated as no study has been done yet.

Methods

A 13 year retrospective study (from 2005 to 2018) was conducted on the urinary stones removed from the patients, admitted at Himalayan Institute of Medical Sciences, Dehradun. The incidence of the disease, site of stones in urinary tract upon diagnosis, composition of removed stones and occurrence of a possible co-relationship between the incidence of the urinary stone disease at different times, age, sex, religion of the patients was investigated.

Results

The frequency of occurrence of urinary stones in males was found to be almost three times more as compared to their female counterparts. The above trend was consistent over the entire period of the study. Interestingly, in the Muslim and Sikh population of the area, females were found to be less prone to the problem as compared to their Hindu counterparts. However, in all religious groups, 21-40 years old subjects were found to be most susceptible to the problem and approximately 90% of the urinary stones were recovered from the kidneys and primarily composed of calcium oxalate.

Conclusion

The co-relationship between the occurrence of urinary stones with age, sex of the patients, their religion & site of stones on diagnosis was found to be statistically significant.

Revolution spectral CT for urinary stone with a single/mixed composition in vivo: a large sample analysis

PURPOSE

To analyze various compositions of urinary stones using revolution spectral CT (rapid kV switching dual-energy CT) in vivo.

METHODS

202 patients with urinary stones underwent spectral CT before surgery. Zeff peak, overall scope and CT values were detected. Moreover, water/iodine attenuating material images were obtained. Removed stones were subjected to infrared spectroscopy after surgery. The results of infrared spectroscopy were compared with CT.

RESULTS

28 stones (14.08%) with single composition, 165 stones with two mixed compositions (81.68%), and 9 stones with three mixed compositions (4.46%) were observed. When Zeff peaks of stones with single/mixed compositions were summarized together, 146 peaks of calcium oxalate monohydrate, 119 peaks of calcium oxalate dihydrate, 55 peaks of carbapatite, 38 peaks of urate, 16 peaks of struvite, and 11 peaks of brushite were totally observed. 93.8% of calcium oxalate monohydrate had Zeff peaks between 13.3 and 14.0. 91.6% of calcium oxalate dihydrate had peaks between 12.0 and 13.3. For carbapatite, 90.9% of stones had peaks from 14.0 to 15.0. A total of 94.8% of urate had peaks between 7.0 and 11.0. 93.8% of struvite had peaks between 11.0 and 13.0, and 90.9% of brushite had peaks between 12.0 and 14.0. Moreover, densities of urate, struvite and brushite were low density in iodine-based images and high-density in water-based images.

CONCLUSION

The in-vivo analysis of spectral CT in urinary stone revealed characteristics of different compositions, especially mixed compositions. An in-vivo predictive model may be constructed to distinguish stone compositions.