Bilan métabolique et prise en charge médicale de la lithiase : une mise au point du CLAFU

2022 Recommendations of the AFU Lithiasis Committee: Medical management - from diagnosis to treatment

The morphological-compositional analysis of urinary stones allows distinguishing schematically several situations: dietary, digestive, metabolic/hormonal, infectious and genetic problems. Blood and urine testing are recommended in the first instance to identify risk factors of urinary stone disease in order to avoid recurrence or progression. The other objective is to detect a potential underlying pathology associated with high risk of urinary stone disease (e.g. primary hyperparathyroidism, primary or enteric hyperoxaluria, cystinuria, distal renal tubular acidosis) that may require specific management. Lifestyle-diet measures are the basis of the management of all stone types, but pharmacological treatments may be required. METHODOLOGY: These recommendations were developed using two methods: the Clinical Practice Recommendation (CPR) method and the ADAPTE method, depending on whether the question was considered in the European Association of Urology (EAU) recommendations (https://uroweb.org/guidelines/urolithiasis) [EAU 2022] and their adaptability to the French context.

Evaluation and understanding of automated urinary stone recognition methods

OBJECTIVE

To assess the potential of automated machine-learning methods for recognizing urinary stones in endoscopy.

MATERIALS AND METHODS

Surface and section images of 123 urinary calculi (109 ex vivo and 14 in vivo stones) were acquired using ureteroscopes. The stones were more than 85% 'pure'. Six classes of urolithiasis were represented: Groups I (calcium oxalate monohydrate, whewellite), II (calcium oxalate dihydrate, weddellite), III (uric acid), IV (brushite and struvite stones), and V (cystine). The automated stone recognition methods that were developed for this study followed two types of approach: shallow classification methods and deep-learning-based methods. Their sensitivity, specificity and positive predictive value (PPV) were evaluated by simultaneously using stone surface and section images to classify them into one of the main morphological groups (subgroups were not considered in this study).

RESULTS

Using shallow methods (based on texture and colour criteria), relatively high sensitivity, specificity and PPV for the six classes were attained: 91%, 90% and 89%, respectively, for whewellite; 99%, 98% and 99% for weddellite; 88%, 89% and 88% for uric acid; 91%, 89% and 90% for struvite; 99%, 99% and 99% for cystine; and 94%, 98% and 99% for brushite. Using deep-learning methods, the sensitivity, specificity and PPV for each of the classes were as follows: 99%, 98% and 97% for whewellite; 98%, 98% and 98% for weddellite; 97%, 98% and 98% for uric acid; 97%, 97% and 96% for struvite; 99%, 99% and 99% for cystine; and 94%, 97% and 98% for brushite.

CONCLUSION

Endoscopic stone recognition is challenging, and few urologists have sufficient expertise to achieve a diagnosis performance comparable to morpho-constitutional analysis. This work is a proof of concept that artificial intelligence could be a solution, with promising results achieved for pure stones. Further studies on a larger panel of stones (pure and mixed) are needed to further develop these methods.

[The basis of endoscopic stones recognition, a prospective monocentric study]

INTRODUCTION

To evaluate by junior urologists the morphology of urinary stone using visual endoscopic recognition after expert teaching. Material From December 2017 to May 2018, surface and section stone pictures extracted from digital ureteroscopy had been submitted to description and recognition. Participants could take benefit from an expert coaching. Each stone was evaluated by a different coherence questionnaire (score 1-5).

RESULTS

Nine stones had been analyzed by 15 junior urologists. Mean score was initially 1.94/4 and then from 2.07 to 4.07/5 during the study. A perfect stone recognition and a matching etiological lithiasis research had been observed in 40.7% and 55.6% of cases respectively.

CONCLUSION

This first teaching experience of the urinary stone morphological endoscopic typing confirms the possibility to train urologists to gain this specific initial skill. Thereby, they could play a more important role in the etiological and diagnostic lithiasis research.

Metabolic Syndrome and Kidney Stone Disease: A Systematic Review of Literature

INTRODUCTION

Worldwide obesity has more than doubled since 1980 with more than 600 million obese patients in 2014. Metabolic syndrome (MetS) is the co-occurrence of metabolic abnormalities, including centrally distributed obesity, hypertension, dyslipidemia, and hyperglycemia. With a concurrent rise in the incidence of kidney stone disease, we wanted to conduct a systematic review focused on the association of MetS to nephrolithiasis.

MATERIALS AND METHODS

A systematic review was performed according to the Cochrane and preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines on all English language articles for the following relevant keywords: association, metabolic syndrome, metabolic syndrome traits, syndrome X, nephrolithiasis, kidney stones, and renal calculi. Our inclusion criteria were studies comparing the prevalence of kidney stone disease in patients with and without MetS.

RESULTS

The initial literature search identified 355 potentially relevant studies. After screening, 22 full text articles were reviewed and 6 (219,255 patients) were included in the final review. All studies displayed increasing odds of nephrolithiasis with increasing number of MetS traits, where patients with three or more MetS traits tended to have a higher prevalence of nephrolithiasis. Studies also showed different significant components of MetS contributing to nephrolithiasis.

CONCLUSIONS

Our review shows a definite association of MetS with kidney stone disease. Although multifactorial in etiology, lifestyle and dietary factors seem to be increasingly important in prevention of stone disease.

[Urinary stones and bowel diseases: Systematic review]

PURPOSE

The aim of the study was to explain the relationship between urinary stones and bowel disease.

METHODS

A systematic review was performed on Medline, Embase and Cochrane using following keywords: urinary stones; urolithiasis; bowel; enteric and digestive. The literature selection was based on evidence and practical considerations.

RESULTS

Fifty-three articles were selected. Three types of urolthiasis are mainly involved in digestive pathologies: calcium oxalate stones, uric acid and ammonium acid urate stones. Bowel pathologies responsible for stone disease are divided into small bowel diseases, colonic lesions and lack of an oxalate degrading bacteria (Oxalobacter formigenes) in the intestinal flora. Resulting in a decreased urine output, pH, hyperoxaluria, hypocitraturia or a hypomagnesurie. Blood and urinary explorations are the basis of diagnostic management.

CONCLUSION

Bowel diseases can be responsible for urolthiasis. Understanding of the mechanisms, and metabolic evaluations can prevent recurrences. Increase fluid intake associated with specific supplementation and diet are the key of the treatment.

[Effectiveness of flexible ureteroscopy versus extracorporeal shock wave lithotripsy for kidney stones treatment]

Primary endpoint was to objective a better effectiveness of flexible ureteroscopy (fURS) compared to extracorporeal shock wave lithotripsy (ESWL) 3 months after treatment of a unique kidney stone from 5 to 20mm. Secondary endpoints were to evaluate effectiveness in subgroup and tolerance. We conducted a prospective comparative randomised trial between May 2012 and February 2014. A computerised tomography was done before treatment and another 3 months after treatment. Of the 30 randomised patients, 8 dropped out from the study and 4 were lost to follow-up. Median time of follow-up was 3.82 months. In per-protocol analysis, success rate was 60% for fURS group versus 28.6% for ESWL group (P=0.29). In intention to treat analysis, success rate was 77.8% in fURS group versus 53.8% in ESWL group (P=0.38). In ESWL group, 5 patients (41.7%) needed a second treatment versus none in fURS group but it was not significant. During follow-up, 1 patient in each group presented a complication. Results of this feasibility study did not allowed to conclude on superiority of a technic. A multicenter study with more important enrollment is necessary considering economic side and tolerance of these treatments.