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The 7^th ESD Conference has come to an end, and in this special edition of Stone News, we have selected key highlights from the event, focusing on some of the most relevant advances in Kidney stone disease.

For this issue, i am pleased to cede the content to Professor Athanasios Papatsoris, from the National and Kapodistrian University of Athens and Sismanoglio General Hospital, who offers his expert insights on key topics discussed during the conference. These include distal tubular acidosis, management of struvite stones, novel molecules, stone analysis, and digital tools for patient care.

Enjoy the read!

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Distal Renal Tubular Acidosis (dRTA) is a renal tubular disorder characterized by a reduced ability of the distal nephron to secrete hydrogen ions (H⁺) into the urine. This defect leads to systemic metabolic acidosis and a persistently alkaline urine (pH > 6). The acid-base imbalance triggers bone resorption, as the skeleton attempts to buffer the excess acid by releasing calcium salts, resulting in hypercalciuria and often hypocitraturia—both recognized risk factors for kidney stone formation.

The urinary environment in dRTA—with alkaline pH, high calcium, and low citrate—favors the development of calcium phosphate stones (apatite and brushite) and calcium oxalate dihydrate stones.

Dr. Guimerà proposes a triple approach for managing idiopathic stone formers with dRTA:

1. Alkalinize the urine with citrate (e.g. Lit-Control^® pH Up) to increase urinary citrate and help correct systemic acidosis.
2. Use phytate (e.g. Lit-Control^® pH Balance) to inhibit bone resorption.
3. Administer thiazides to reduce urinary calcium excretion.

Patients with dRTA should be actively identified and treated not only to address the systemic acidosis, but also to correct its metabolic consequences, particularly hypercalciuria and hypocitraturia, in order to prevent stone recurrence. 

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Struvite stones are infection-related calculi, formed in the presence of urease-producing bacteria that elevate urinary pH and promote the crystallization of magnesium ammonium phosphate. These stones often grow rapidly and may develop into large staghorn calculi, making them particularly complex to manage.

The standard treatment includes complete surgical removal, typically via percutaneous nephrolithotomy, along with appropriate antibiotic therapy. In recent years, metabolic strategies have gained attention for their role in long-term prevention. A study by Siener et al., published in 2016 (Urolithiasis), showed that a single dose of L-methionine (1500 mg) significantly lowered urinary pH and reduced the relative supersaturation of struvite by 34% and brushite by 25%, without increasing urinary calcium excretion.

Furthermore, a 10-year prospective study conducted by Siener and Hesse, published in 1996 in Urological Research, evaluated long-term use of L-methionine (1500–3000 mg/day) in patients with recurrent struvite stones. The results showed that urinary pH decreased from 7.5 to 5.5, with 90% of patients remaining stone-free and 84% without recurrent UTIs over the follow-up period. Crucially, no cases of metabolic acidosis were observed, confirming the efficacy and long-term safety of L-methionine as a therapeutic agent.

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The morphocompositional analysis of kidney stones offers unique insight into the origin and development of stones, revealing nucleation conditions, growth patterns, and the involvement of factors like infection or drug-induced crystallization. Unlike metabolic studies, which reflect a patient’s current state, this analysis reconstructs the stone’s formation history. Despite recommendations from the European Association of Urology to analyze at least one stone per patient, this practice remains uncommon, and outdated chemical methods—often inaccurate, especially for mixed stones—are still widely used.

The ideal approach combines stereoscopic microscopy, SEM-EDS, and FTIR, enabling the detection of both major and minor components, including markers of subclinical infection. In this context, stone culture can identify embedded pathogens often missed in routine urine tests, highlighting its value in recurrent cases.

At the Renal Lithiasis Research Laboratory (University of the Balearic Islands), over 15,000 stones have been analyzed using this method, resulting in comprehensive reports with therapeutic, diagnostic, and dietary recommendations, transforming the stone into a critical tool for personalized prevention and care.

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The myLit-Control^® App is the first mobile health application specifically designed for kidney stone patients, offering an interactive and intuitive platform to support daily monitoring, education, and long-term prevention. It allows users to track essential health parameters such as water intake, urinary pH, and treatment intake, which are key to reducing the risk of stone recurrence.

Beyond tracking, the app provides educational resources to help patients better understand their condition and make informed lifestyle choices. One of its most innovative features is its gamified structure, encouraging users to complete health-related challenges and receive rewards, such as discounts on relevant products.

The app also delivers smart notifications—reminders to hydrate, monitor pH, and take medication—ensuring that patients remain engaged and consistently adhere to their treatment plan.

Supported by multiple clinical studies, the myLit-Control^® App has proven to be a valuable tool in enhancing treatment adherence, patient empowerment, and overall disease management. It represents a significant step forward in the digital transformation of kidney stone prevention through personalized and proactive care.

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