Routine ultrasound and blood tests after laparoscopic cholecystectomy-are they worthwhile? A diagnostic accuracy study.

Abstract

Delayed recognition of complications can have life-threatening sequelae and is a leading cause of medical litigation. Minimal evidence exists for benefits of postoperative surveillance. This study investigated whether ultrasound (US) and blood tests can detect complications after laparoscopic cholecystectomy. A series of 772 laparoscopic cholecystectomies performed between February 2008 and October 2009 was retrospectively analyzed. Routine US was performed within 6h postoperatively, and a blood sample was taken at the second postoperative day. Postoperative US was performed in 722 patients. Fluid accumulation was documented in 104 patients; only two of these patients had clinically significant findings requiring treatment. The best predictor of infectious complications was elevated postoperative C-reactive protein (≥123mg/L), with an area under the curve (AUC) of 0.94 and a number needed to misdiagnose (NNM) of 8.7. To predict postoperative choledocholithiasis, a combination of total bilirubin, aspartate aminotransferase and alkaline phosphatase elevations, with cutoff values of 1.3mg/dL, 37IU/L, and 136IU/L, respectively, attained the highest accuracy with a NNM of 29.5. Ultrasonographic detection of bile duct dilation further improved specificity, while lowering sensitivity. The value of early routine postoperative US is low, unless there is clinical suspicion of complications. Routine blood tests have a high sensitivity for infectious complications and a high specificity for remnant biliary duct stones. Therefore, we recommend avoiding routine US postoperatively and performing routine postoperative blood tests. We also recommend facilitating easy access to postoperative US, as it can aid the decision to take therapeutic measures in symptomatic patients.