Kidney Week

Abstract: PO2255

A Case of Sevelamer-Induced Colon Perforation

Session Information

• Pathology and Lab Medicine: Clinical
  October 22, 2020 | Location: On-Demand
  Abstract Time: 10:00 AM - 12:00 PM

Category: Trainee Case Report

• 1602 Pathology and Lab Medicine: Clinical

Authors

• Manchala, Venkata Ramana, University of Arkansas for Medical Sciences, Little Rock, Arkansas, United States

Venkata Ramana Manchala,

• Mandalapu, Rajendra, University of Arkansas for Medical Sciences, Little Rock, Arkansas, United States

Rajendra Mandalapu,

• Thumma, Soumya Preethi, University of Arkansas for Medical Sciences, Little Rock, Arkansas, United States

Soumya Preethi Thumma,

• Karakala, Nithin, University of Arkansas for Medical Sciences, Little Rock, Arkansas, United States

Nithin Karakala,

Introduction

Sevelamer is an anion exchange resin used to treat hyperphosphatemia in patients with chronic kidney disease. It does not cause hypercalcemia or vascular calcification associated calcium based phosphate binders. Common adverse effects include nausea, vomiting, diarrhea, dyspepsia and constipation ¹. Case reports of sevelamer associated bowel perforation have been reported in the literature². Here we report a case of sevelamer induced colon perforation.

Case Description

61 year old Caucasian male with history of ESRD from diabetic nephropathy on automated peritoneal dialysis presented to the emergency department with abdominal pain. Physical exam was notable for epigastric tenderness. Labs were unremarkable except for hyperglycemia of 427 mg/dL. CT scan abdomen showed cholelithiasis and moderate ascites. PD fluid analysis ruled out peritonitis. Patient’s abdominal pain persisted despite several days of supportive care, prompting repeat CT scan abdomen which revealed large pneumoperitoneum with possible colon perforation. Patient was emergently taken for exploratory laparotomy requiring right hemicolectomy with ileocolic anastomosis. Histopathological exam of the resected colon showed scattered yellow eosinophilic, acellular crystalline material with "fish scale" morphology within the lumen suggestive of sevelamer resins. Patient was on sevelamer 800mg TID for several years. Patient improved with appropriate medical management. Sevelamer was discontinued prior to discharge.

Discussion

Sevelamer is composed of a non-absorbable hydrogel with ammonia on the hydrochloride (Renagel) or the carbonate (Renvela). In the acid milieu of stomach, the polymer dissociates from its anion, is protonated to ammonium which is available to bind phosphate in the intestine³. The exact pathogenesis of intestinal perforation remains unclear. It is hypothesized that presence of sevelamer crystals in the gastrointestinal tract was associated with mucosal abnormalities including inflammation, ischemia and necrosis. Recognition of characteristic sevelamer crystals (typically seen as bright pink linear accentuations with a rusty yellow background and irregularly spaced fish-scales) on pathology along with the supporting clinical history clinches the diagnosis.
It is important for clinicians to be aware of this rare but a serious potential complication of bowel perforation associated with sevelamer.