Background and aims: Restorative proctocolectomy with ileal pouch-anal anastomosis (IPAA) has become a standard of care in patients with ulcerative colitis (UC). Nephrolithiasis is common in patients with inflammatory bowel disease (IBD), but has never been studied as a complication of IPAA. We aimed to assess the risk factors for nephrolithiasis in patients with IPAA.
Methods: Using an IRB-approved, prospectively maintained pouch registry, we identified 1221 patients between 2000 and 2010. Those with post-IPAA nephrolithiasis served as the study group whereas IPAA patients without nephrolithiasis served as the controls. Demographic and clinical variables were analyzed using multivariable logistic regression to identify risk factors.
Results: There were a total of 218 IPAA patients: 81 with nephrolithiasis (37%) and 137 without (63%). Of the 81 patients in the study group, 17 were excluded due to limited clinical data. Three risk factors were found to be associated with nephrolithiasis: the presence of extra-intestinal manifestations (odd's ratio [OR] = 2.9, 95% confidence interval [CI]: 1.4, 5.8, p = 0.003), no use of antibiotics (OR = 3.2, 95% CI: 1.5, 6.5, p = 0.002) and low serum bicarbonate level (OR = 0.87, 95% CI: 0.77, 0.99, p = 0.038).
Conclusion: Nephrolithiasis was a common finding in our patients with IPAA. As pouch patients with nephrolithiasis can develop adverse clinical complications, those with at least one of the risk factors we identified may need to be monitored more closely and possibly receive prophylactic treatment with oral bicarbonate.
Keywords: Inflammatory bowel disease; Ileal pouch anal anastomosis; Kidney stones; Nephrolithiasis; Restorative proctocolectomy; Ulcerative colitis
Journal Article. 5075 words. Illustrated.
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