[Cystine lithiasis: study of a series of 116 cases]. / Lithiase cystinique: enseignements de l'étude d'une série de 116 cas.

INTRODUCTION: Cystine stones is a rare disease, related to a genetic metabolic disease. Its management must treat both the stones and their complications, and prevent recurrences by controlling cystinuria. OBJECTIVE: The objective of this study was to define the natural history of cystine stones, identify reliable diagnostic criteria and propose a simple treatment regimen. MATERIAL AND METHOD: The authors studied the clinical, biochemical and radiological data of a retrospective series of 116 cases, treated by the same urologist between 1953 and 1999. RESULTS: Cystinuria is often diagnosed in young adults on the basis of urine biochemistry (Brand's reaction, urinary cystine assay) or spectrophotometric analysis of the stones or urinary crystals. This assessment, not performed routinely, must be guided by a family history, recurrent stones or following failure of lithotripsy. The appearance of the stones, macroscopically a waxy yellow, radiologically only slightly opaque with a large component in the renal pelvis associated with a small round caliceal stones, is highly suggestive. Radiological assessment by IVU is generally sufficient. Treatment of the disease is medical and surgical: dietary measures, alkalinization of the urine and possibly drug treatments, are associated with extracorporeal lithotripsy or surgical treatment. These modalities eliminate cystine stones in 70% of cases. Recurrent stones are observed in 42% of cases followed for more than 5 years, mainly due to the presence of residual fragments (60% of recurrences). Surveillance and dietary measures must be maintained for life. Surveillance is based on biannual radiographic follow-up (plain x-rays +/- ultrasound) to detect and consequently treat small stones. A test for cystinuria must be proposed to all relatives of affected patients. CONCLUSION: This disease presents very polymorphic clinical features and clinical course. It can be responsible for impaired renal function and must therefore be investigated in the presence of suggestive clinical signs or history to avoid a delayed diagnosis, as treatment modalities are available to decrease the frequency of recurrence and which can potentiate treatment by surgical or lithotripsy. However, there are no predictive factors of deterioration of the disease, and biannual surveillance, for life, is essential to detect and treat small stones.

[Urinary calculi, consisting of dehydrated calcium phosphate. Clinical, biological, radiologic aspects, clinical course and management]. / Lithiase urinaire de brushite. Particularités cliniques, biologiques, radiologiques, évolutives et thérapeutiques.

Seventeen cases of urinary calculi analyzed by infrared spectrophotometry were found to be composed entirely or nearly entirely of bihydrated calcium hydrophosphate. The observations are summarized here. This type of stone occurs with a frequency of about 1% (0.85% in our experience) of all urinary calculi, predominantly in men (14 of our 17 cases). Diagnosis is based on the physical and chemical analysis of the stone and on infrared spectrophotometry. Most of these stones are pure or nearly pure compounds. The macroscopic aspect of the stones or fragments of stones can guide diagnosis. These stones are cream coloured stones with a smooth regular outer surface. Broken fragments show the same cream colour, sometimes with strips radiating from the centre of the fracture surface. Radiologically, these stones are homogeneously radio-opaque, often oval-shaped with a regular outline. Blood tests can demonstrate suspected or proven hyperparathyroidism (4 out of 10 cases in our 17 observations) with hypercalcemia, hypophosphatemia and hypercalciuria. Complementary examinations may be needed to search for a parathyroid adenoma. With or without hyperparathyroidism, 24-h urinalysis usually shows hypercalciuria up to ro over 500 to 600 mg/24 h. Crystallization usually occurs in the upper urinary tract, in the bladder or in indwelling catheters. These stones are extremely hard and are difficult to break in vitro. To be successful, lithotripsy requires prolonged treatment: up to 3000 to 6000 shockwaves at 22-23 kv with the Dornier apparatus. Despite the notion of hypercalciuria, the pathogenesis of bihydrated calcium hydrophosphate calculi remains to be elucidated.

[Extracorporeal shockwave lithotripsy and cystine lithiasis. Our experience apropos of 11 cases]. / Lithotritie extracorporelle par ondes de choc et lithiase cystinique. Notre expérience à propos de onze cas.

The authors report their experience of the treatment of cystine lithiasis by ESWL on the basis of 11 cases from 1984 to 1987.