Ultrasonographic and histopathological features in 8 cats with fibrotic small intestinal stricture.

Andrew Holloway,Roberta Rasotto,Mauro Pivetta

doi:10.1111/vru.12756

Abstract

Benign stricture is an uncommon cause of chronic small intestinal obstruction in the cat. The purpose of this retrospective case series was to describe the ultrasonographic features, histopathological findings, and clinical presentation in a group of cats with benign small intestinal stricture. Inclusion criteria were cats presenting during the period 2010-2017, and that had ultrasonography and small intestinal stricture confirmed at surgery. For each cat, clinical data and ultrasonographic findings were retrieved from the medical record, and histopathology, where available, was reviewed. Eight cats met the inclusion criteria. The location of strictures was duodenum (1/8), mid- to distal jejunum (4/8), and ileum (3/8). Ultrasonographic findings included gastric distension (8/8) and generalized (3/8) or segmental (5/8) intestinal dilation consistent with mechanical obstruction. Ingesta did not propagate beyond the strictured segment. Wall thickening was mild to moderate (3-6mm). Normal wall layering was disrupted in all cats. Strictures were predominantly hypoechoic (7/8) and associated with hyperechoic peri-intestinal mesentery (6/8). Annular strictures (5/8) were less than 15mm in length whereas long-segment strictures (3/8) were greater than 15mm in length. Histopathology showed transmural disease with fibrosis and inflammation (8/8), often (6/8) extending into the bordering mesentery. The mucosa was the most severely affected layer and epithelial injury accompanied the mucosal fibrosis/inflammation. Clinical presentation reflected delayed diagnosis of chronic bowel obstruction with debilitation (8/8), marked weight loss (8/8), and prerenal azotemia (5/8). Benign fibrostenotic stricture should be considered a differential diagnosis in debilitated young cats presenting with chronic bowel disease and ultrasonographic features of intestinal obstruction.

Highlights

Chronic intestinal obstruction may result from intraluminal foreign body, intussusception or intestinal stenosis caused by intra – or extramural disease.[1,2,3,4]
The clinical signs of chronic obstruction are non-specific including inappetence, lethargy, vomiting, weight loss and diarrhoea and must be distinguished from inflammatory bowel disease (IBD), intestinal small cell lymphoma (ISCL), hyperthyroidism, dietary and infectious disease which can present with similar clinical signs.[1,4,5,6]
This report demonstrates that the transition zone in fibrotic strictures causing small intestinal obstruction in the cat is variable in length and can present as either an annular or as a long-segment stricture

Summary

Introduction

Chronic intestinal obstruction may result from intraluminal foreign body, intussusception or intestinal stenosis caused by intra – or extramural disease.[1,2,3,4] The clinical signs of chronic obstruction are non-specific including inappetence, lethargy, vomiting, weight loss and diarrhoea and must be distinguished from inflammatory bowel disease (IBD), intestinal small cell lymphoma (ISCL), hyperthyroidism, dietary and infectious disease which can present with similar clinical signs.[1,4,5,6] Intramural intestinal obstruction in the cat is usually caused by intestinal wall neoplasia.[1,4,7] Nonneoplastic intramural obstruction is uncommon arising secondary to pyogranuloma, duplication cyst and, occasionally, due to benign intestinal stricture.[1,8]A benign intestinal stricture is a circumscribed narrowing or stenosis of the intestinal lumen caused by inflammation, adhesion, incarceration or cicatricial contracture (fibrostenotic stricture).[9]. Strictures are usually solitary lesions and the extent of the intestinal stenosis may be focal and annular or involve long segments of bowel, and result in partial or complete intestinal obstruction.[10,11,12,13] Reports of benign stricture in the veterinary literature are rare but have been described in the dog as a postanastomotic complication, due to strangulation associated with spontaneous mesenteric hernia and secondary to rupture of a congenital intestinal diverticulum.[1,14]

Methods

Results

Discussion

Conclusion