1.
Effect of parathyroidectomy on renal stone recurrence.
Charles, PY, Letavernier, E, Périé, S, Gauthé, M, Daudon, M, Haymann, JP
Urolithiasis. 2021;(4):327-334
Abstract
Parathyroidectomy (PTX) is routinely performed in hypercalciuric renal stone patients with primary hyperparathyroidism (PHPT). However, some data indicate a persistent stone activity following PTX, raising the issue of the link between PHPT and stone disease. We performed an observational study on 30 renal stone patients diagnosed with PHPT. Patients were selected among 1448 hypercalciuric patients referred in our department for a diagnostic evaluation. Patients with no parathyroid surgery or any biological follow-up were excluded. Clinical and biological data (including 24-h urine collection and a calcium load test) were collected before and within 12 months following surgery. Stone recurrence was evaluated by direct phone contact (median 43 months). Comparison of biological data before and after surgery showed a significant decrease of ionized calcium and serum parathyroid hormone after PTX. All stones contained calcium-dependent species such as carbapatite, brushite or dihydrate calcium oxalate. Urine saturation indexes and calciuria significantly decreased after surgery (from 9.9 to 5.9 mmol/d, p < 0.0001), but a persistent hypercalciuria was detected in 47% of patients. The other stone risk factors including diuresis stayed similar. Stone activity that was increasing (from 0.20-0.30 to 0.50-0.75/year) the 2 years before PTX, significantly decreased after surgery [0.05-0.15/year (p < 0.001)]. PTX in calcium-dependent renal stone formers with PHPT significantly decreases both stone recurrence and urine saturation indexes. However, PTX unmasked an underlying renal stone disease related to idiopathic hypercalciuria in half of patients with a remaining stone activity, testifying the need for patient's follow-up to prevent stone recurrence.
2.
Changes in separate renal function in patients who underwent minimally invasive renal stone surgery according to the preoperative functional deterioration.
Choo, MS, Park, J, Cho, MC, Son, H, Jeong, H, Cho, SY
Scientific reports. 2019;(1):3610
Abstract
The significant predictors for the postoperative deterioration of separate renal function after minimally invasive stone surgery were investigated in the present prospective and observational study. A total of 117 consecutive patients who underwent retrograde intrarenal surgery or mini-percutaneous nephrolithotomy for renal calculi >10 mm were included in the present study. Perioperative changes in separate renal function were evaluated with Technetium-99m-Diethylene TriaminePenta acetic acid scan prior to intervention and at postoperative 3 months. Based on the functional differences between bilateral renal units, deterioration of separate renal function was graded into the following three groups: normal deterioration (<10%), moderate deterioration (10-20%), and severe deterioration (>20%). A total of 46 patients had a normal separate renal function, while 71 (60.7%) showed abnormal separate function in the involved side, including 29 (24.8%) moderate and 42 (35.9%) severe deterioration. Postoperatively, 48 patients (41.0%) showed aggravation or no recovery of separate renal function. Of the 46 patients with normal separate function, only 9 patients (19.5%) showed postoperative aggravation. Patients with moderate and severe deterioration showed aggravation (n = 7, 24.1%) or no recovery of separate renal function (n = 32, 76.1%, P < 0.001). Preoperative severe deterioration of separate renal function was an independent significant predictor for the postoperative deterioration of renal function (OR: 9.09, 95% CI: 4.007-20.624, P < 0.001). Lower preoperative deterioration of separate renal function showed a high probability of functional recovery. Therefore, it is hypothesized that early intervention might be necessary in cases where the patient exhibits severe aggravation of renal function.
3.
How Protective Mechanisms Interact to Prevent Overnight Calcium Phosphate Precipitation - An Observational Study to Determine Factors Against Calcium Phosphate Lithogenesis in a Healthy Cohort.
Shafiee, MA, Logan, AG, Halperin, ML
Nephron. 2016;(3):238-43
Abstract
BACKGROUND/AIMS: As restful, non-interrupted sleep is essential for normal mental and physical functioning, the urine flow rate (UFR) overnight remains low. Due to this reduced UFR, the kidneys produce a lower urine volume, which may lead to supersaturation of lithogens in the renal collecting system. The protective mechanisms that prevent the rise in the concentration of the lithogenic substances in urine, such as calcium phosphate, are explored. METHODS Urine samples were collected from 26 subjects every 2-3 h during daylight with one nocturnal collection; the UFR was calculated in the median time for each collection period. Urinary constituents for calcium phosphate precipitation including electrolytes, calcium, phosphate, citrate, and pH were measured. Comparisons within individuals were done by paired t test. RESULTS The calcium excretion rate fell significantly overnight (from 2.4 ± 0.2 µmol/min during the daytime to 1.5 ± 0.3 µmol/min, p < 0.05), in parallel with sodium excretion (54 ± 16 µmol/min from its daytime 127 ± 12 µmol/min, p < 0.05), preventing nocturnal calcium concentration from increasing (3.0 ± 0.3 mmol/l daytime to 2.5 ± 0.5 mmol/l overnight), while citrate concentration did not change significantly. The total urine phosphate concentration rose significantly overnight (daytime 18.7 ± 1.4 µmol/min vs. nocturnal 20.9 ± 1.7 µmol/min), but the concentration of divalent phosphate did not increase in the overnight period. CONCLUSIONS Although the UFR was lower overnight, there was no evidence that the risk of calcium phosphate precipitate formation in healthy subjects was increased.