Metabolic Diagnosis of Nephrolithiasis. Clinical cases (Part I)

Abstract

Nephrolithiasis is one of the most frequent causes of hospitalization in nephrology and urology units in our country and is an important source of discomfort in affected patients. Despite the availability of modern, minimally invasive endourological procedures to remove stones from the urinary tract, prevention of stone recurrences remains an essential strategy. Chemical analysis of stones, whether passed spontaneously or removed surgically, is a crucial step in etiological diagnostics aimed at devising adequate prevention strategies. Modern endoscopic lithotripsy techniques provide complete fragmentation of stones and, compared to extracorporeal shock wave lithotripsy, have the advantage of avoiding painful elimination of fragments through the urinary tract. This means, however, that stone fragments are often unavailable for analysis, thereby depriving the nephrologist of an important tool for diagnosis. As a consequence, metabolic evaluation tends to be the only means of establishing the etiology of stones and preventing their recurrence. Among patients attending our kidney stone center, we selected five clinical cases representative of a rational diagnostic workup in specific clinical contexts. Two of these nephrolithiasis cases (in a patient with osteoporosis and in a patient with primary hyperparathyroidism) are reported here (Part I); the remaining three will be discussed in the next issue of this journal (Part II).