Oxalate nephropathy in a diabetic patient after gastric by-pass.

We report a case of 48-year-old woman with history of diabetes and hypertension, who presented with acute to chronic kidney injury. Sixteen months before presentation, she had undergone Roux-en-Y gastric by-pass (RYGB) for morbid obesity. Kidney biopsy showed lesions consistent with oxalate nephropathy and deposition of calcium oxalate crystals. An extensive workshop excluded other causes of kidney injury. The patient subsequently required dialysis with no improvement of renal function on follow-up. The mechanism by which patients develop hyperoxaluria after RYGB remains obscure; it is suggested that RYGB provokes fat malabsorption, which results in increased load of free fatty acid in the intestine. Thus, calcium binds to free fatty acids provoking reduced synthesis of calcium oxalate. Consequently, increased quantity of oxalate remains free and is absorbed in the intestine causing hyperoxaluria. Similar to our case, oxalate nephropathy after RYGB is seen in patients with diabetes, hypertension and chronic kidney injury. Treatment includes low-fat, low-oxalate diet along with administration of calcium supplements. Unfortunately, prognosis is rather poor with the majority of patients eventually requiring permanent dialysis. Therefore, patients with history of chronic kidney disease undergoing RYGB should be closely monitored, particularly those with long standing history of diabetes and hypertension.

Sclerosing encapsulating peritonitis secondary to CAPD: the effect of fibrotic debridement on further dialysis.

BACKGROUND: Sclerosing peritonitis (SCP) is a complication of continuous ambulatory peritoneal dialysis (CAPD) and is characterized by progressive fibrosis of the peritoneum. Entrapment of the intestine in a fibrous sac resulting in complete intestinal obstruction is called sclerosing-encapsulating peritonitis (SEP) and represents the most severe form of the disease. Various reports have been pessimistic regarding the surgical outcome when SEP has caused complete intestinal obstruction. Continuation of CAPD after laparotomy is generally considered not feasible. The aim of this article is to present our experience in the surgical management of SEP and, in particular, in the postoperative continuation of CAPD. MATERIAL AND METHODS: Seventeen consecutive patients with SCP among 175 patients undergoing CAPD during a period of 14 years in a single Unit were retrospectively reviewed. Two groups of patients were recognized. The SCP group included 9 patients with incomplete intestinal obstruction that were treated with single peritoneal catheter removal and switching to haemodialysis. The SEP group included 8 patients with complete obstruction that necessitated laparotomy for surgical debridement of the fibrotic tissue and release of the intestinal loops. RESULTS: Switching to haemodialysis improved the majority of the group of patients. In 2 of the SEP group of patients (early in the series), where enterectomy was inevitable, performance of an intestinal anastomosis resulted in leakage with subsequent fatal outcome. Two of the SEP group of patients were transferred to haemodialysis after the laparotomy. In the remaining 4 SEP patients (50%), exposure of a significant portion of active peritoneal surface was achieved - called "neoperitonization"-and allowed effective continuation of peritoneal dialysis for an average duration of 16 months (range 1-32). CONCLUSIONS: In patients with SEP, careful release of the intestinal loops avoiding enterectomies and even inadvertent intestinal wounds is mandatory. Continuation of peritoneal dialysis after meticulous debridement and removal of the fibrotic tissue is possible and may be effective. To the best of our knowledge, there have not been previously reported cases of continuations of CAPD after laparotomy for SEP.