Histologic Findings of Intestine after Injection of Tumor Necrosis Factor-alpha in Rats - Comparison with Gross Findings -

Abstract

Deciding a resection margin or extent of manipulation during a surgery of necrotizing enterocolitis(NEC) is difficult due to irregular wide spectrum of gros findings. Pathologic features of NEC is a nonspecific inflammation compatible with ischemic necrosis, findings represents distended loops of intestine with serosal edema, hemorrhage and peritoneal fluid, and normal segment alternate with irregular gray or reddish black blotch as the disease progress. Tumor necrosis factor-alpha(TNF) is a cytokine which is able to produce bowel necrosis invivo. Experimental NEC has been impossible to reproduce with diverse etiologic factors, and TNF has been known to involve in the pathophysiology of NEC7). Our aim is 1) to confirm the effect of TNF to produce bowel necrosis, 2) to compare gross and histologic findings of different part of gastrointestinal tract after TNF infusion, and 3) to validate the concept of minimal surgery. TNF was infused into Sprague-Dawley rats(N=6) via right femoral vein over 10 minutes, and bowel necrosis was observed in 4 out of 6 after 60 minutes. Istologic examination of distal ileum showed same degree of mucosal damage irrespective to irregular gross findings. Jejunum showed worst transmuaral necrosis which is not commpatible with gross findings. These resultsnot a reliable clue for deciding a resection margin, and second look surgery of minimal surgery is recommended in NEC.