Analysis of Comparative Studies Using Different Contrast Agents for Endoscopic Retrograde Cholangiopancreatography

Abstract

Abstract: Pancreatitis induced by ERCP ha been associated with numerous pathogenic factors such as a previous history of pancreatitis, acinarization, mechanical and thermal injury, medications, and lastly the type of contrast agent used. Conventional contrast agents are characterized by both ionicity and high osmolality. These traditional agents have demonstrated deleterious effects upon multiple organ systems. Newer contrast agents have been developed with properties of low osmolality and non‐ionicity in efforts to their decrease potential toxic effects, This review analyzes the current literature regarding the role of different contrast agents in the incidence of ERCP related pancreatitis.Nine randomized, double‐blind, prospective studies have been published comparing low and high osmolality contrast agents for ERCP. Although five studies have shown lower degrees of amylase/lipase elevation after ERCP for the low osmolality agents, only three studies demonstrated a statistically significant advantage for the reduction of clinical pancreatitis among the low osmolality agent groups. In addition, these studies also varied in terms of specific contrast agents used, inclusion and exclusion criteria, rates of acinarization, and definition of clinical pancreatitis. However, after combining all of the data from these studies, there was a statistically significant advantage in reducing ERCP induced pancreatitis for non‐ionic, low osmolality agents (1.44%) compared with the ionic, high osmolality agents (7.39%) [p = 0.007] and the ionic, low osmolality agents (9.67%) [p = 0.0001]. There was no statistical difference between the ionic, high osmolality agents and the ionic, low osmolaltiy agents [p = 0.5481. This data seem to suggest that ionicity rather than osmolality may play a more significant role in the incidence of ERCP induced pancreatitis. The major disadvantage of the use of low osmolality, non‐ionic agents is their relatively high cost. Overall, controversy remains about whether these newer agents should be utilized in all patients or be selectively used in only high risk patients. Presently, we utilize these agents routinely.