Epidemiologic, Tomographic, and Infrared Spectroscopic Analysis of Double J Stent Encrustations.

Introduction: Double J (DJ) stent is a common medical device, and it may become encrusted, causing significant concern. Understanding the composition and associated risk factors for encrusted stents is crucial for appropriate management.

Objective: The aim of the study was to evaluate the types of DJ encrustation by infrared spectroscopy and correlate them with patient characteristics and computerized tomographic (CT) findings.

Methods: All encrusted stents surgically removed over a 1-year period underwent infrared spectroscopy analysis, and types of encrustations were compared with the patient's demographic, clinical, and imaging features. For categorical variables, frequency tables were generated, and for comparing continuous measurements across multiple groups, the Kruskal-Wallis test was used, considering p < 0.05 as statistically significant.

Results: Thirty-three patients were included; the mean age was 46 years, and the mean BMI was 32.9 ± 8.98 kg/m2. The average DJ indwelling time was 8.3 ± 7.78 months. Spectroscopic analysis: 34.3% struvite, 22.8% uric acid, 17.1% calcium oxalate, 11.4% ammonium urate, 5.7% brushite, 5.7% calcium oxalate dihydrate, and 2.9% protein. Lower urine pH was associated with uric acid encrustations (p = 0.017). Uric acid and urate encrustations presented significantly lower densities on CT readings (p = 0.043). Brushite prevalence was surprisingly high in our series, and therefore, it has to be considered for early DJ encrustation.

Conclusion: The types of mineral deposits depicted in our study differed from the literature, where calcium oxalate is the most common; therefore, other compositions such as struvite and uric acid/ammonium urate should be considered. Urine pH demonstrated an association with uric acid and urate calcifications, which can be predicted by lower densities in CT readings.