Oxalate Nephropathy Causing Irreversible Renal Failure After Roux-en-Y Gastric Bypass Surgery

Oxalate nephropathy after RYGB, albeit rare, has a poor prognosis with a rapid progression to kidney failure. Oxalate nephropathy has many etiologies and is one of the rare causes of renal failure. A 39-year-old diabetic woman came to our nephrology clinic because of a progressive increase in serum creatinine from 1 to 4.2. She had a history of Roux-en-Y gastric bypass (RYGB) surgery six months earlier. In view of the unexplained progressive increase in creatinine, a kidney biopsy was done. The histological diagnosis of oxalate nephropathy with diabetic nephropathy class 2b was made. Oxalate nephropathy is a rare and most severe renal complication after bariatric surgery that is reported in some patients after jejunoileal bypass and RYGB surgery. Oxalate nephropathy is progressive in nature and has a poor prognosis. In our case, oxalate nephropathy and kidney failure occurred six months after RYGB surgery. Since the histological finding in our patient revealed oxalate nephropathy with diabetic nephropathy class 2b, it seems diabetic nephropathy can probably facilitate calcium oxalate crystals formation. This important point should be considered that oxalate nephropathy could rapidly progress to renal failure; so, patients who undergo Roux-en-Y gastric bypass surgery should have regular follow-ups.