[Occurrence of uroliths - age-, breed-, and gender-specific differences in dogs from Germany]. / Auftreten von Harnsteinen ­ alters-, rasse- und geschlechtsspezifische Unterschiede bei Hunden aus Deutschland.

OBJECTIVES: The aim of this study was to assess the distribution and frequency of uroliths in dogs in Germany and to evaluate age-, gender-, and breed-specific differences. MATERIAL AND METHODS: A total of 2772 uroliths from dogs in Germany that had been submitted from veterinary practices during the years 2017-2019 were analyzed by infrared spectroscopy. RESULTS: Uroliths were analyzed as follows: Struvite (44.7 %), calcium oxalate monohydrate (whewellite 24.5 %), cystine (15.2 %), ammonium urate (5.3 %), calcium oxalate dihydrate (weddellite 4.4 %), calcium phosphate (1.6 %), xanthine (1.2 %), whewellite/weddellite (11 %), brushite (0.4 %) and other substances (1.7 %). The dogs' median age (in years) with regards to the urolith type amounted to: struvite 8, calcium oxalate (whewellite and weddellite) 10, cystine 5, brushite 11, xanthine 6.5, and ammonium urate 6 years. Struvite uroliths were most common in intact females (83.8 %) and neutered females (80.8 %), while cystine uroliths (36.7 %) and calcium oxalates (35.7 % whewellite and weddellite) were most common in intact males. Calcium oxalate (50 %), struvite (17.3 %), and cystine uroliths (10.5 %) were found in male neutered dogs. The most frequent breeds with struvite uroliths were Pug (75.9 %), Labrador (73.1 %), Shih Tzu (62.2 %), Dachshund (50.4 %) and Maltese (36 %). Calcium oxalates were most frequently encountered in the breeds Miniature Schnauzer (54.8 %), Jack Russell Terrier (49.5 %), and Yorkshire Terrier (48.2 %). Cystine uroliths were most frequent in the breeds French Bulldog (47.2 %), Bulldogs (44.8 %), Chihuahua (44.1 %) and Dachshund (32.8 %). CONCLUSION AND CLINICAL RELEVANCE: Dogs from Germany displayed age-, gender- and breed-specific differences in the frequency of urine calculi occurrence. Knowledge of the frequent occurrence of the distinct uroliths in Germany as well as potential breed dispositions allow the veterinarian to implement an appropriate preventive treatment plan. This would involve a targeted monitoring program for the prevention and follow-up care of the patient in conjunction with the pet owner.

The Association of Encrustation and Ureteral Stent Indwelling Time in Urolithiasis and KUB Grading System.

PURPOSE: To evaluate the management of prolonged indwelling ureteral stents and the newly developed KUB (kidney, ureter, and bladder) grading system for the classification of encrusted stents in urolithiasis. METHOD: This study involved 69 patients that had indwelling and forgotten ureteral stents for more than 6 months after urolithiasis treatment. They were categorized into 4 groups based on indwelling time and were reviewed retrospectively. Patients whose ureteral stent could not be removed with simple cystoscopy were graded according to stone surface area and the KUB system. RESULTS: The mean stent indwelling time was 23.1 months. Stone burden in KUB and, in proportion to that, total KUB (T) score showed increased association that was directly proportional to indwelling time (p < 0.001, p = 0.008). Surgical intervention was required in 73.9% of patients. Among patients requiring surgery, 78.4% were treated in a single session and multi-modal interventions were performed in 70.5%. K score ? 3 was found to be associated with multiple surgery requirements (odds ratio [OR];11.25, %95 confidence interval [CI]:2.132-59.375),multi-modal procedure requirements (OR;16.50, %95 CI:3.434-79.826 ), and lower stone-free rates (p = 0.04). Bscore ? 3 was associated with multi-modal procedure requirements (OR;8.90, %95 CI:1.052-75.462). U score ? 3and T score ? 9 were associated with an operating time >180 minutes (p < 0.001, p = 0.008). CONCLUSION: Prolonged indwelling time of the ureteral stent in urolithiasis is associated with increased encrustation and stone burden. Since the KUB system specifies stone burden and its particular localization, it can be used as a simple, convenient method for the planning treatment of encrusted ureteral stents.

[Etiopathogenic factors of the different types of urinary litiasis.] / Factores etiopatogénicos de los diferentes tipos de urolitiasis.

In this review, we analyze the etiopathogenic principles of urinary lithiasis formation. In the kidney, calcifications that may cause renal lithiasis are produced as a consequence of processes that injury the urothelium at the papilla and Bellini's ducts. With the improvement of imaging techniques, mainly micro CT scan, it is possible to detect them and we may be able to anticipate to the formation of lithiasis. As we well know, there are different factors that influence the formation of the calculi depending on their composition. In calcium lithiasis it is key to review the modification of the categories of hypercalciuria, we currently distinguish two types instead of three, thanks to the fasting calcium/ creatinine ratio, differentiating absorptive hypercalciuria and fasting hypercalciuria. In the fasting hypercalciuria, it is important to emphasize the relationship between this factor and the loss of bone mineral density in patients with recurrent renal calcic lithiasis, so that in this kind of patients it is compulsory the study of bone metabolism by bone remodelling markers and bone densitometry. Regarding the other factors that participate in the formation of calcium lithiasis we should specially emphasize on hypercalciuria and its growing increase because of its relationship with obesity and metabolic syndrome, as well as hipocitraturia, present in an important percentage of patients and related in some cases with metabolic acidosis and osteopenia-osteoporosis too. In relation to uric acid lithiasis it should be highlighted that urinary pH is the most determinant factor and, therefore, its control and modifications would be paramount for prevention of this type of lithiasis. In the infectious lithiasis, the presence of germs that split urea is mandatory. They generate ammonia ions with the ability to injure the urothelium and to form magnesium ammonium phosphate lithiasis mainly. Regarding cystine lithiasis, rare, it was classically divided in three types and now passed to be classified in type A and B depending on the muted gene, and it is more useful to perform direct 24-hour urine measurement than screening tests which have low sensitivity. In general, we tried to give a comprehensive view of the various types of lithiasis emphasizing the most interesting clinical points for the urologist.

Children with spinal abnormalities have an increased health burden from upper tract urolithiasis.

OBJECTIVE: To examine the epidemiology and health care burden of upper tract urolithiasis in children with spinal abnormalities using a large, national database. Children with spinal dysraphism are predisposed to urolithiasis for many reasons, including immobility, bacteriuria, and urinary stasis. No large epidemiologic studies exist regarding stones in this specific group. Isolated spinal curvature may lead to hypercalciuria from immobility; however, urolithiasis rates are unknown. METHODS: We extracted data from the Pediatric Health Information Systems database over an 8-year period. Hospitals reporting inpatient visits, emergency room visits, and ambulatory surgery visits were included. Using International Classification of Diseases, Ninth Revision codes and Current Procedural Terminology codes, we identified children with upper tract urolithiasis, spinal dysraphism, and spinal curvature. Data regarding demographics, prevalence, surgical procedures, costs related to stone procedures were extracted. RESULTS: A total of 11,987 patients had urolithiasis. Prevalence of stones in patients with normal spines was 0.24% compared with 1.40% and 4.03% among children with spinal curvature and spinal dysraphism, respectively (P<.001). Children with spinal curvature and spinal dysraphism were more likely to have multiple procedures for stones than those without spinal abnormalities (25% vs 25.7% vs 13.1%, P<.001). Costs per patient were significantly higher for children with spinal abnormalities compared with those with normal spines. CONCLUSION: Children with spinal curvature and spinal dysraphism have a much greater rate of upper tract urolithiasis, resulting in more procedures and related costs. Urolithiasis represents a significant, chronic health burden for children with spinal abnormalities. Screening and preventive care may reduce the impact of urolithiasis in these patients.