Comparative Study of the Quantity of Gas in the Bowel in Simple and Closed-Loop Obstruction. ∗

Abstract

The results of previous studies have indicated that whereas the accumulation of gas as detected by X-ray examination is a reliable agent in the early diagnosis of simple obstruction, in strangulation obstructions Roentgen evidence is not of the same value in its early recognition. 1 , 2 , 3 . The results of the following study are based on direct measurements of gas in simple and closed-loop obstructions.

Method: Studies of 36 dogs form the basis of this report. Dogs with closed-loop rather than strangulation obstructions were used in this comparison because the dogs with strangulation obstructions only survive for short periods. In the closed-loop, as a rule there are no gross vascular changes until late in the course of the obstruction at which time closed-loop obstruction partakes of the features of strangulation obstruction. In the closed loop obstruction the oral source of gas has been eliminated and in establishing this type of obstruction every trace of gas was “milked out” of the bowel before the last bowel end was inverted. Thirty-one closed-loop obstructions of small bowel of varying lengths and at various sites were established by the usual standard methods. The dogs were then observed for various lengths of time and either killed when they appeared moribund or were reoperated upon before they reached this stage. At operation the closed-loops were removed and immediately thereafter the gas and contents were measured by aspiration with a syringe and hollow needle. The length of gut, site and duration of obstruction were accurately recorded in all cases. In some the diameter of the bowel was also measured. If the dogs were killed, an autopsy was performed immediately after death and similar measurements of the gas, fluid contents, etc., were made.