Long-term incidence of urolithiasis post-bariatric surgery

Abstract

Introduction: The risk of urolithiasis post-Roux-en-Y gastric bypass (RYGB) surgery is higher when compared to the general population. Calcium and vitamin D supplementation is routinely prescribed to these patients, yet compliance with these supplements is unknown. The aim of this study was to assess the incidence of symptomatic de novo urolithiasis post-RYGB and compliance with calcium and vitamin D supplementation. Methods: A standardized telephone questionnaire was administered to patients who underwent RYGB between 1996 and 2011. Personal and medical histories were obtained with emphasis on episodes of symptomatic urolithiasis and calcium and vitamin D supplementation. Results: The response rate was 48% with 478 patients completing the telephone questionnaire. After a mean follow-up of 7.0 years (range: 1-15), the incidence of post-RYGB symptomatic urolithiasis was 7.3%, while the rate of de novo symptomatic urolithiasis was 5%. The overall median time to present with symptomatic urolithiasis was 3.1 years, with 3.3 years for de novo stone-formers, and 2.0 years for recurrent stone-formers (p = 0.38). In de novo stone-formers, 33% presented with symptomatic urolithiasis 4 to 14 years postoperatively. Compliance with calcium and vitamin D supplementation was 56% and 51%, respectively. Conclusions: Despite recall bias and lack of confirmatory imaging studies, a high postoperative incidence of symptomatic urolithiasis was found in a large sample of post-RYGB patients. A third of patients with de novo stones, presented with symptomatic urolithiasis 4 to 14 years postoperatively. Compliance with postoperative calcium and vitamin D supplementation was poor and needs improvement.

Urinary Lithiasis Risk Assessment after Bariatric Surgery

“…The largest cohort on this subject, with nearly 4636 American patients who underwent GB surgery, showed an increased risk of urolithiasis in operated patients, with 7.65% of them presenting with stones, whereas only 4.63% of obese non-operated patients did [ 4 ]. These results are consistent with those of a Canadian phone study showing a 7.3% incidence of renal colic after gastric bypass [ 5 ].…”

“…Despite large studies [ 3 , 5 ], reviews [ 8 , 9 , 10 ], and meta-analyses [ 6 , 11 ], we did not find a tool to evaluate the risk of urolithiasis after GB. We established a rapid and reliable screening questionnaire to evaluate the risk of urolithiasis after gastric bypass.…”

“…Currently, there is no screening protocol for the risk of urolithiasis after bypass surgery. Urolithiasis leads to increased medical morbidities and medical costs due to hospital stays and surgical procedures [ 2 , 4 , 5 ]. This study aimed to create and evaluate the accuracy of a simple and short retrospective questionnaire for urolithiasis risk assessment after bypass surgery.…”

Kidney Stones After Bariatric Surgery: Risk Assessment and Mitigation

“…34 The median BMI before surgery was 51 kg/m 2 and the mean follow-up after RYGB was 7 years. The rate of overall post-RYGB symptomatic urolithiasis was 7.3% (35 patients out of 478) with a median stone incident time of 3.1 years following RYGB.…”

“…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.…”