A comparative histopathologic evaluation of the effects of three differentsolutions used for whole bowel irrigation: An experimental study

Purpose: Although whole bowel irrigation (WBI) is a widely used method of b owel preparation in daily surgical practice, almost nothing is known about the histopathologic alterations caused by WBI and whether these differences have any detrimental effect on the outcome of gastrointestinal surgical pr ocedures. Therefore, an experimental study has been conducted to evaluate a nd compare the effects of WBI with various solutions on the histology of ga strointestinal tract. Methods: During the experimental procedures animals were divided into 4 gro ups consisting of 8 animals each as follows: group A, WBI performed by usin g isotonic saline solution; group B, WBI performed by using an isoosmolar s olution containing polyethylene glycol (PEG); group C,WBI performed by usin g Lactated Ringer's solution; group D, Animals that were not irrigated but sham operations that were performed served as controls. Four hours after WB I the animals underwent laparotomy and a segment of transverse colon with i ntact vascular peduncle was prepared. After waiting for 30 minutes, specime ns from duodenum, small intestine, large bower, colonic segment, and liver were obtained from each animal. Histopathologically, all of the specimens w ere evaluated and graded by 3 parameters including congestion, edema, and i nflammation. Results: Although varying degrees of congestion, edema, and inflammation we re encountered from all of the specimens of group A, B, and C, only slight congestion was noted in all specimens of group D. The difference between gr oup D and other groups was statistically very significant (P < .001). When the sections from duodenums of groups were evaluated, the degree of congest ion, edema, and inflammation were found to be moderate in group B, mild-mod erate in group A, and mild in group C. Histopathologic examinations of spec imens of the small, large bowel, and isolated colonic segment showed severe congestion, edema, and inflammation in group A, moderate-mild in group B, and mild in group C. The difference between A and B, A and C, and A and D w as statistically significant (P < .01). Although severe congestion was enco untered in liver specimens of group A, only mild congestion was encountered in groups B and C(P = .0001). The matched durations of irrigations and tot al volume of irrigation solutions were found to be not related with the dif ference in histopathologic findings. Conclusions: WBI has induced varying deg rees of histopathologic alteration s from mild to severe in the rat gastrointestinal tract. Lactated Ringer's solution and PEG solution have induced the least alterations. Therefore, WB I with Lactated Ringer's solution and PEG solution seem to be safe alternat ives of mechanical bowel preparation before elective large bowel surgery. B ecause saline solution has caused detrimental alterations in distal gastroi ntestinal tract histology, WBI with saline solution seems to be unadvisable . Copyright (C) 2000 by W.B. Saunders Company.