Urinary Evaluation After RYGBP: a Lithogenic Profile with Early Postoperative Increase in the Incidence of Urolithiasis

Abstract

RYGBP determined profound changes in urinary composition which predisposed to a lithogenic profile. The prevalence of urinary lithiasis increased almost 70% in the postoperative period. Postoperative urinary oxalate and uric acid were the only predictors for new stone formers.

Risk of nephrolithiasis, hyperoxaluria, and calcium oxalate supersaturation increased after Roux-en-Y gastric bypass surgery: a systematic review and meta-analysis

“…We separately analyzed data in 2 types of studies. First, we compared baseline urine chemistries before and after bariatric surgery, including 24-hour urine brushite SS (4 studies [16][17][18][19]), calcium (7 studies [16][17][18][19][20][21][22]), citrate (7 studies [16][17][18][19][20][21][22]), calcium oxalate SS (6 studies [16][17][18][19][20][21]), uric acid SS (5 studies [16][17][18][19]21]), oxalate (7 studies [16][17][18][19][20][21][22]), urine pH (6 studies [16,[18][19][20][21][22]), phosphorus (5 studies [16][17][18][19][20]), and volume (6 studies [16][17]<...>…”

Kidney Stones After Bariatric Surgery: Risk Assessment and Mitigation

“…17 Twelve months after RYGB, both mean urinary citrate levels (268 to 170 mg/day) and urine volumes (1.31 to 0.93 L/day) significantly ( p < 0.001) decreased by 36% and 29%, respectively. Of note, all 151 patients were found to be hypocitraturic at 12 months post-RYGB.…”

“…In addition, their group also found hyperuricosuria to be a significant predictor of developing nephrolithiasis 1 year after RYGB (OR 1.09, 95% CI 1.002-1.016; p = 0.013). 17 In 2015 Lieske et al reported an 11.1% incidence in bariatric patients over a mean follow-up of 6 years compared with a 4.3% in obese controls. 30 Most of the bariatric procedures performed (n = 591, 78%) were standard RYGB surgeries.…”

“…A summary of mean 24-h urine data from retrospective RYGB, SG, or gastric banding surgeries are stratified by stone history in Table 1. [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28] Prospectively collected 24-h urine chemistry profiles from primarily nonstone formers before and after either RYGB (n = 275) or BPD (n = 2) procedure are summarized in Table 1. [14][15][16][17][18][19] In the six prospective studies, 24-h urine chemistry profiles collected from 277 patients in a mean of 11 months after RYGB or BPD, revealed a 36.4% increase (28 to 44 mg/day) in urine oxalate levels after their bariatric surgery.…”

“…Kidney stone incidence with at least 2 years followup in obese patients or following bariatric surgery. 17,[32][33][34][35][36][37] associated with decreased calcium stone risks in patients with low oxalate urine excretion levels. 41 Recently, Sakhaee et al assessed 24 and 15 patients, at a mean of 4.7 and 4.2 years after RYGB, respectively, in two-phase, randomized placebo crossover studies comparing the effect of a potassium citrate combined formula, potassium-calcium citrate (PCC), on calcium oxalate crystallization.…”