DOES NEOSTIGMINE HAVE A DELETERIOUS EFFECT ON THE RESISTANCE OF COLONIC ANASTOMOSES

The aim of the present study was to evaluate the effects of neostigmin e as a final anaesthetic manoeuvre on colonic anastomoses. A colonic a nastomosis was constructed in 40 Sprague-Dawley rats. The animals were divided into two groups: (1) rats receiving intravenous saline soluti on (placebo); and (2) rats receiving an intravenous injection of neost igmine. The size of the caecum, and the diameters of the preanastomoti c and post-anastomotic colon were measured during the operation and 4 days after surgery, when all the animals were sacrificed. At this time , the presence of adhesions was also investigated. Each segment contai ning an anastomosis was removed, and the bursting pressure and burstin g wall tension were determined. Loss of caecum diameter was significan tly greater in group 2 than in group 1 (P=0.03). Dilatation and obstru ction of the colon were significantly more frequent in group 1 (dilata tion, P=0.01; obstruction, P=0.047). Also, consumption of water by gro up 2 was greater than that by group 1 (P=0.049). No statistically sign ificant differences were found between the diameters of the colon (pre -and post-anastomosis), or with respect to general adhesions and adhes ions to the anastomotic line. No significant differences were found be tween anastomotic resistance (determined in terms of bursting pressure and bursting wall tension) in the two groups. The inclusion of neosti gmine in an anaesthetic protocol under experimental setting did not re duce the resistance of colonic anastomoses and did not compromise norm al healing. Moreover, obstruction caused by peristaltic weakness might be prevented by the expulsion of stool that is induced by the strong contraction of the colonic smooth muscle.