Serum amylase isoenzymes in patients undergoing operation for ruptured andnon-ruptured abdominal aortic aneurysm

Objective: Previous work has suggested that hyperamylasemia in patients who undergo operation for ruptured abdominal aortic aneurysm (AAA) is associat ed with poor outcome. The aims of this study were to determine, for the fir st time, the source of serum amylase in such patients and to examine the pr ognostic significance of amylase isoenzyme expression. Methods: This study was designed as a prospective clinical and laboratory s tudy. The study consisted of 40 patients who underwent operation for ruptur ed AAA and 10 patients who underwent operation for non-ruptured AAA. The ma in outcome measures were serum total and pancreatic and salivary amylase ac tivities determined with enzymatic colorimetric assay before operation and 6 hours after aortic clamp release. Results: Five of 40 patients (12.5%) with rupture and one of 10 patients (1 0%) with non-rupture had elevated total amylase levels before operation, an d seven of 31 patients (23%) with rupture and five of 10 patients (50%) wit h non-rupture had elevated total amylase levels after operation. The preope rative salivary amylase (P =.05) and postoperative pancreatic amylase (P <. 02) levels were significantly lower in ruptured AAA as compared with non-ru ptured AAA. The preoperative salivary amylase level was significantly lower in non-survivors of rupture, such that a level equal to or less than 45 U/ L was associated with death in 11 of 13 patients (85%). Conclusion: These data do not support previous works that suggest that hype ramylasemia is associated with poor outcome in ruptured AAA. By contrast, a low preoperative salivary amylase level was associated with increased mort ality in ruptured AAA and may be a marker of the severity of shock.