Is there an association between urolithiasis and roux-en-y gastric bypass surgery?

Abstract

Purpose: Several studies have documented high incidence of urinary lithiasis after jejunoileal by-pass. Roux-en-y gastric bypass surgery (RYGB) is currently the most common bariatric procedure. Because of its difficult for absorption, RYGB has a potential risk to increase the incidence of lithiasis. This study was conducted in order to test the hypothesis that RYGB increases the incidence urolithiasis after 50% of excessive weight loss. Materials and Methods:We performed a retrospective cohort study to evaluate 58 patients who underwent RYGB at the Obesity Service at Santa Casa de Misericordia de Sao Paulo, between 2000 and 2005, with minimum follow-up of 10 and maximum of 72 months, after the procedure. Results: Forty-five (77.6%) patients had ≥ 50% loss of weight excess. There was no difference between the frequency of urolithiasis before and after the procedure, and nephrolithiasis was observed after surgery in only one patient, however this had been detected before the procedure. Conclusion: In the period studied, RYGB does not seem to affect the incidence of urolithiasis after weight reduction. This may be due to its smaller malabsorptive component as compared with jejunoileal "by-pass", thereby possibly not significantly influencing the oxalate metabolism.

Association of Kidney Stone Disease (KSD) with Primary Gastrointestinal Surgery: a Systematic Review over Last 2 Decades

“…This is then exacerbated by GI surgery where segments are resected or rendered dysfunctional. This state of hyperoxaluria leads to urinary calcium oxalate supersaturation which then leads to crystal aggregation and stone formation [10,21,22]. It is also reported that the other factors which increase the risk of KSD in this population are low volume and hypocitraturia.…”

“…There are 5 case series [8][9][10][11][12], 3 retrospective cohort studies [13, 14•, 15], 3 prospective cohort studies [16•, 17•, 18] and 1 case-control study [19•] (Tables 1 and 2). Majority of the studies took place in the USA (n = 9) with two studies authored in Brazil and one in Japan.…”

“…Ascertainment of KSD diagnosis ranged from clinical history to different imaging modalities. The most popular method was imaging (n = 5), of which two studies relied on ultrasound (US) [10,11]; only one study relied on computed tomography (CT) only [17•]; and two studies relied on a combination of US or CT or magnetic resonance imaging [12, 16•]. Other studies mentioned the identification of patients via coding [14•, 15, 16•] or clinical history [9], but they did not state the imaging modality of diagnosis, which is presumed to be during follow-up of their primary GI pathology.…”

“…Mukewar was the only study to use both clinical history and formal imaging to ensure those patients were caught [16•]. Of interest, the two Brazilian studies relied on US imaging for diagnosis of KSD [10,11]. The use of US imaging (rather than CT) as a first line might lead to underdiagnosing KSD in these patient groups, and the highly inconsistent incidence rates support this (1.7% and 17.9%, respectively) [10,11].…”

Kidney Stones After Bariatric Surgery: Risk Assessment and Mitigation

“…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.…”