OBJECTIVES

To describe the demographics of patients undergoing supine PCNL (s-PCNL) and prone PCNL (p-PCNL) at Veterans Memorial Medical Center (VMMC) and to compare different data collected between the two approaches.

Retrospective data collection was done through chart review of patients who underwent supine and prone PCNL at VMMC from 2018 to 2022. Information collected includes patient demographics, clinical profile, stone burden and laterality, surgical technique, hospital days, complications and management.

A total of 176 cases, 132 s-PCNL and 44 p-PCNL, were included. Demographic data show no statistical difference as to age and sex. There is no statistical difference in the stone burden, stone density, and Guy’s stone scores between the two groups. There was no statistical difference in the mean operative time and stone free rates between the two groups. Mean hospital stay was 6.11 days for s-PCNL and 6.76 for p-PCNL, with significant statistical difference in favor of s-PCNL. Complication rates were 15.2% for supine PCNL and 13.6% for prone PCNL. There was no statistical significant difference in Clavien-Dindo complications between the two groups. There was no mortality reported for both groups.

There is an observed increasing trend in the number of supine PCNL versus prone PCNL from 2018 to 2022. Supine PCNL is as effective and safe as prone PCNL. Supine PCNL appears to be more beneficial in terms of hospital stay in days. However, one limitation of the study its being retrospective and collated data which is the cause of the discrepancy in sample population size between the two groups.

Renal calculus is a common disease with complex etiology and high recurrence rate. Recent studies have revealed that gene mutations may lead to metabolic defects which are associated with the formation of renal calculus, and single gene mutation is involved in relative high proportion of renal calculus. Gene mutations cause changes in enzyme function, metabolic pathway, ion transport, and receptor sensitivity, causing defects in oxalic acid metabolism, cystine metabolism, calcium ion metabolism, or purine metabolism, which may lead to the formation of renal calculus. The hereditary conditions associated with renal calculus include primary hyperoxaluria, cystinuria, Dent disease, familial hypomagnesemia with hypercalciuria and nephrocalcinosis, Bartter syndrome, primary distal renal tubular acidosis, infant hypercalcemia, hereditary hypophosphatemic rickets with hypercalciuria, adenine phosphoribosyltransferase deficiency, hypoxanthine-guanine phosphoribosyltransferase deficiency, and hereditary xanthinuria. This article reviews the research progress on renal calculus associated with inborn error of metabolism, to provide reference for early screening, diagnosis, treatment, prevention and recurrence of renal calculus.
Infant ; Humans ; Hypercalciuria/genetics* ; Kidney Calculi/genetics* ; Urolithiasis/genetics* ; Nephrocalcinosis/genetics* ; Metabolism, Inborn Errors/genetics*

Kidney stone is a highly recurrent disease in the urinary tract system. Most kidney stones are calcium stones, usually consisting of either calcium oxalate or calcium phosphate. Supersaturation of soluble calcium, oxalate, phosphate, and citrate in the urine is the basis for calcium stone formation. Genetics, diet, low physical activity, and individual habits contribute to the formation of kidney stones. In this review, the associations of the risk of kidney stones with oxalate consumption and some individual habits, such as smoking, alcohol drinking, and opium consumption, are summarized.
Humans ; Calcium/urine* ; Oxalates ; Kidney Calculi/urine* ; Calcium Oxalate/urine* ; Habits

This paper analyzed the clinical data, diagnosis and treatment of 4 asymptomatic patients with ureteral calculi without hydrops in our hospital from October 2018 to January 2019, and comprehensively discussed the previous literature. The 4 patients in this group had no obvious clinical symptoms, no positive stones were found in the B-ultrasound of the urinary system, and no hydroureter and hydroureter of the affected side was found. Urinary CT scan confirmed ureteral stones. They were all located in the lower ureter, and the stones obstructed the lumen. The stones were round and smooth, and there was no obvious hyperplasia and edema in the surrounding mucosa. The lithotripsy was completed in the first-stage operation, and the DJ catheter was left behind for one month after the operation. Based on the clinical diagnosis and treatment process of the 4 cases of asymptomatic calculi in this group and the analysis of previous studies, these patients were mostly detected by imaging examinations or other systematic imaging examinations during the regular review of urinary calculi. Ureteral stones with obstruction did not necessarily have stone-related symptoms. The onset of renal colic involved an increase in intraluminal pressure, related stimulation of nerve endings, smooth muscle spasms caused by stretching of the ureteral wall, and systemic changes in cytokines and related hormones. Cascade reactions, etc., were associated with the movement of stones down. Ureteral stones without hydrops were mostly located in the lower ureter, which had a certain buffering effect on obstructive pressure. Asymptomatic ureteral calculi could also induce irreversible damage to renal function, and the proportion of damage increased with the diameter of the stone. Patients with a history of urinary calculi, especially those with asymptomatic stones for the first time, should be paid attention to during clinical follow-up. At present, there are few research reports on asymptomatic and non-accumulating ureteral calculi. We analyze the clinical diagnosis and treatment process and characteristics of this group of patients combined with previous literature to provide a reference for the diagnosis and treatment of such patients.
Humans ; Ureteral Calculi/therapy* ; Urinary Calculi/therapy* ; Ureter ; Lithotripsy/methods* ; Edema/therapy* ; Kidney Calculi/therapy*

OBJECTIVE: To investigate the efficacy and safety of laparoscopic pyeloplasty combined with ultrasonic lithotripsy via nephroscope in the treatment of ureteropelvic junction obstruction (UPJO) with renal calculi. METHODS: From June 2016 to January 2022, eight patients including five males and three females underwent laparoscopic pyeloplasty combined with ultrasonic lithotripsy via 19.5F(1F≈0.33 mm) nephroscope in Peking University People' s Hospital. The age ranged from 23-51 years (mean: 40.5 years) and the body mass index (BMI) ranged from 18.8-32.4 kg/m² (mean 27.0 kg/m²). The lesion located on the left side in all of the eight patients. Two patients had solitary kidney and one patient had horseshoe kidney. Solitary stone was seen in one patient and the other seven patients suffered multiple stones, with two patients had staghorn stones. The largest diameter of stones ranged from 0.6-2.5 cm (mean: 1.5 cm). CT or ultrasound showed that moderate nephrosis was seen in five patients and severe nephrosis was seen in three patients. During surgery, after exposure of renal pelvis and proximal ureter, a small incision of 1.5 cm was performed in the anterior wall of the renal pelvis, and a 19.5F nephroscope was introduced into renal pelvis through laparoscopic trocar and renal pelvis incision. Stones were fragmented and sucked out by 3.3 mm ultrasonic probe placed through nephroscope. After stones were removed, modified laparoscopic pyeloplasty was performed. RESULTS: Surgery was successfully completed in all of the eight patients without conversion to open surgery. The operation time ranged from 160-254 min (mean 213 min) and the time of nephroscopic management time was 25-40 min (mean: 33 min). The hemoglobin was decreased by 3-21 g/L (mean: 10.3 g/L). The stone-free rate was 75% (6/8 cases), stones were incompletely removed in two patients due to abnormal intrarenal structure. The modified Clavien classification system (MCCS) grade ⅢA complication occurred in one patient postoperatively, which was nephrosis due to intrarenal bleeding, and nephrostomy was performed. With the mean follow-up of 30 months (ranged from 2-68 months), there was no evidence of obstruction in all the patients, and one patient underwent percutaneous nephrolithotomy to treat residual calculi. CONCLUSION Laparoscopic pyeloplasty combined with ultrasonic lithotripsy via 19.5F nephroscope is feasible and safe, and could be a complementary method to treat UPJO and renal calculi.
Adult ; Female ; Humans ; Kidney Calculi/surgery* ; Kidney Pelvis ; Laparoscopy/methods* ; Lithotripsy ; Male ; Middle Aged ; Nephrosis/surgery* ; Ureter ; Ureteral Obstruction/surgery* ; Young Adult

OBJECTIVE: To evaluate the relationship between 24 h urinary ion content and kidney stones, and to explore the diagnostic values of kidney stone in primary gout patients. METHODS: Patients diagnosed with primary gout had ultrasound scanning of both feet and kidneys in Peking University First Hospital from Jan. 2020 to May 2021. Their clinical characteristics were compared between the positive and negative kidney stone groups, and the relationship between kidney stone and urinary ion composition were analyzed. Risk factors of kidney stone were analyzed. The explored diagnostic values were evaluated for urinary oxalate and citrate according with uric acid kidney stones by dual-energy computed tomography (DECT). RESULTS: Among the 100 gouty patients, 80 patients had uric acid crystal deposition in lower joints of extremity by ultrasonography, 61 patients had kidney stone, and 34 had kidney uric acid stones by DECT. All the multiple kidney stones were proved as uric acid kidney stones by DECT. Compared with patients without kidney stone group proved by ultrasonography, patients with kidney stone had longer gouty duration [(48.7±26.6) months vs. (84.0±30.6) months, P=0.01], higher 24 h urinary oxalate [(20.1±9.6) mg vs. (28.6±20.7) mg, P=0.001] and lower 24 h urinary citrate [(506.3±315.4) mg vs. (355.7±219.6) mg, P=0.001]. Compared with the patients without kidney stone by DECT, the patients with uric acid kidney stone also had longer disease duration [(49.1±28.4) months vs. (108.3±72.2) months, P=0.001], higher 24 h urinary oxalate [(23.6±16.9) mg vs. (28.5±18.8) mg, P < 0.05], lower 24 h urinary citrate [(556.0±316.3) mg vs. (391.7±261.2) mg, P < 0.05], higher serum uric acid [(466.2±134.5) μmol/L vs. (517.2±18.1) μmol/L, P < 0.05] and higher 24 h urinary uric acid [(1 518.1±893.4) mg vs. (1 684.2±812.1) mg, P < 0.05]. Logistic regression analysis showed long gout disease duration (OR=1.229, 95%CI: 1.062-1.522, P < 0.05), high serum uric acid level (OR=1.137, 95%CI: 1.001-1.213, P=0.01), low 24 h urinary citrate (OR=0.821, 95%CI: 0.659-0.952, P=0.01) were all risk factors of kidney stones by ultrasonography. Also, long gout disease duration (OR=1.201, 95%CI: 1.101-1.437, P=0.005), high serum creatine uric level (OR=1.145, 95%CI: 1.001-1.182, P=0.04), low 24 h urinary citrate (OR=0.837, 95%CI: 0.739-0.931, P=0.02) were all risk factors of kidney uric acid stones by DECT. CONCLUSION Long disease duration and low 24 h urinary citrate were risk factors for kidney stones.
Humans ; Urinary Calculi ; Uric Acid/analysis* ; Citric Acid ; Kidney Calculi/diagnostic imaging* ; Gout/diagnostic imaging* ; Citrates ; Oxalates

Objective: To evaluate the associations of body mass index (BMI) and waist circumference with hospitalization risk of kidney stones in Chinese adults. Methods: This study used long-term follow-up data from China Kadoorie Biobank. After excluding participants with chronic kidney disease, cancer, and extreme BMI or waist circumference values at baseline, 502 096 participants were included in the present analysis. Cox proportional hazards regression models were used to estimate the associations of BMI and waist circumference with hospitalization risk of kidney stones. Results: During an average follow-up period of (10.7±2.2) years, 12 396 participants were hospitalized for the first time with kidney stones. Using the participants with BMI (kg/m²) of 20.5-22.4 as reference, the multivariable-adjusted HR (95%CI) for those with BMI of <18.5, 18.5-20.4, 22.5-23.9, 24.0-25.9, 26.0-27.9, 28.0-29.9, and ≥30.0 were 0.96 (0.87-1.05), 0.94 (0.88-1.00), 1.11 (1.05-1.17), 1.25 (1.18-1.32), 1.29 (1.21-1.37), 1.39 (1.28-1.50), and 1.54 (1.40-1.71), respectively. For every 1 kg/m² increase in BMI, the HR of kidney stones hospitalization increased by 4% (HR=1.04, 95%CI: 1.04-1.05). Using the participants with waist circumference (cm) of 75.0-79.9 as reference, the multivariable-adjusted HR (95%CI) for those with waist circumference of <65.0, 65.0-69.9, 70.0-74.9, 80.0-84.9, 85.0-89.9, 90.0-94.9, and ≥95.0 were 0.82 (0.74-0.91), 0.85 (0.80-0.92), 0.95 (0.89-1.00), 1.16 (1.09-1.22), 1.22 (1.15-1.30), 1.28 (1.19-1.38), and 1.46 (1.35-1.58), respectively. For every 5 cm increase in waist circumference, the HR of kidney stones hospitalization increased by 9% (HR=1.09, 95%CI: 1.08-1.10). After mutually adjusting for BMI and waist circumference in the above models, the association between BMI and hospitalization risk of kidney stones disappeared. In contrast, the association between waist circumference and hospitalization risk of kidney stones remained unchanged. Conclusions: BMI and waist circumference were positively associated with hospitalization risk of kidney stones. The increased waist circumference was an independent risk factor for kidney stones among Chinese adults.
Adult ; Body Mass Index ; Hospitalization ; Humans ; Kidney Calculi/epidemiology* ; Risk Factors ; Waist Circumference

OBJECTIVE: To compare the short-term effects and long-term outcomes of incisional procedure and dilatation procedure to manage diverticular neck in percutaneous nephrolithotomy for diverticular stones. METHODS: Clinical data of 61 patients with diverticular stones who underwent percutaneous nephrolithotomy from June 2009 to January 2019 were retrospectively collected and analyzed, which was as follous: (1) basic information: age, gender, body mass index (BMI), American Society of Anesthesiology (ASA) classifications and preoperative symptoms.(2)stone characteristic and procedure-related data: location and size of stone, skinned renal access length and procedure time.(3)perioperative clinical data: hemoglobin drop, Clavien's classification and stone-free rate. Long-term follow-ups were performed for more than 5 years after the patients were discharged. RESULTS: Fifty-three patients were included based on the inclusion and exclusion criteria, and were divided into the dilation group (n=37) and the incision group (n=16) by the treatment methods of diverticular neck. There were 24 male patients (45.3%) and 29 female patients (54.7%), with a mean age of 39.96±12.88 years. Stones were mainly located in the upper pole (n=32, 60.38%) and posterior area (n=41, 77.4%), with a predominance of single stone (n=36, 67.9%). There was no statistically significant difference in demographic data and stone characteristics between the two groups except for age and stone burden. Forty-five patients (84.9%) reached stone-free status after surgeries, and 44 patients (83.0%) postoperative symptoms improved. Twelve patients were lost to the follow-ups, and 41 cases were followed up for an average of 77 months. One recurrence occurred 1 year after surgery. Fifteen patients underwent operations within the past 5 years and the overall 5-year recurrence rate for the remaining 26 patients was 34.6%. There was no statistically significant difference in the incidence of perioperative complications, postoperative stone-free rate and recurrence rate between the two groups, and the recurrence rate was significantly higher 5 years postoperatively than 1 year postoperatively. The proportion of the patients who remained lithotripsy-free and residual stone status decreased significantly. CONCLUSION Both incisional and dilatation procedures in percutaneous nephrolithotomy to manage diverticular neck could bring the satisfactory postoperative stone free rate. The recurrence rate was about 30% to 40% 5 years after surgery.
Adult ; Female ; Humans ; Kidney Calculi/surgery* ; Male ; Middle Aged ; Nephrolithotomy, Percutaneous ; Nephrostomy, Percutaneous ; Retrospective Studies ; Treatment Outcome

Humans ; Kidney Calculi/surgery* ; Nephrolithotomy, Percutaneous ; Nephrostomy, Percutaneous ; Obesity, Morbid/surgery* ; Radiography ; Retrospective Studies ; Treatment Outcome

BACKGROUND: The dietary habits and lifestyle changes during the COVID-19 pandemic could affect the urinary risk factors in kidney stone formers. In this study, we investigated the effects of the COVID-19 pandemic on 24-h urine metabolites, as a surrogate for dietary intake, in patients with kidney stones, in Tehran, Iran. METHODS: We evaluated the medical records of all patients with urolithiasis who visited in our stone prevention clinic from the beginning of COVID-19 in Iran to 1 year later (Feb 2020-Feb 2021) and compared it with the patients' medical records in the same period a year before COVID-19 (Feb 2019-Feb 2020). RESULTS: The results of our stone prevention clinic showed a decrease in the number of visits during COVID-19. Twenty-four-hour urine urea, sodium, and potassium were significantly lower, and 24-h urine magnesium was significantly higher during COVID-19. Higher 24-h urine oxalate was only shown in patients with the first-time visit, whereas lower 24-h urine uric acid and citrate were only shown in patients with the follow-up visits. CONCLUSIONS COVID-19 pandemics may change some of the dietary habits of the patients, including lower salt, protein, and fruit and vegetable intake. Although economic issues, restricted access, or sanitation issues may be the reason for the undesirable dietary changes, the importance of a quality diet should be discussed with all patients, as possible. Since the number of patients visited in the stone clinic was lower during COVID-19, virtual visits could be an excellent alternative to motivate patients with kidney stones.
COVID-19 ; Humans ; Iran/epidemiology* ; Kidney ; Kidney Calculi/prevention & control* ; Pandemics ; Risk Factors ; SARS-CoV-2