Experimental evaluation of various available contrast agents for use in the gastrointestinal tract in case of suspected leakage. Effects on pleura.

Intrapleural injections of seven contrast agents were carried out in experimental rats in order to find a safe contrast agent to use in the radiological examination of the upper gastrointestinal tract in cases where leakage outside the upper gastrointestinal tract into the pleural space could be suspected, particularly post-operatively. The contrast agent in such cases could enter the mediastinum, pleura, peritoneum or lungs and bronchi. Hexabrix (May and Baker) and Gastrografin (Schering AG) produced the least tissue reaction in the pleura. Due to the potential risk of aspiration in such cases Gastrografin is not suitable as it is known to produce significant reaction in the lungs and may even prove to be fatal. Hexabrix, therefore, appears to be the safest contrast agent where leakage into the pleural space may be suspected.