Comparison of liver function tests after hepatic lobectomy and hepatic wedge resection

Abstract

Prior studies have suggested that changes in liver function tests may vary with the postoperative time interval and may be related to the extent of hepatic resection. This study describes characteristic profiles in parenchymal liver enzymes and other serum liver function tests over a 4-week course comparing anatomic to nonanatomic hepatic resections. The records of 48 patients undergoing successful major hepatic resection during a 3-year period were retrospectively reviewed. Of these 48 patients, 28 underwent formal anatomic resection (hepatic lobectomy), and 20 underwent nonanatomic resections (wedge resection). Routine postoperative management in lobectomy patients included drawing liver function tests and enzymes daily for the first week, then at approximately 2 and 4 weeks postoperatively. These tests included: prothrombin time (PT), partial thromboplastin time, total serum bilirubin, total protein (TP), aspartate transaminase, lactate dehydrogenase (LDH), alkaline phosphatase, albumin (A), and glucose. Patients undergoing wedge resections had these values checked less frequently, approximately 3 to 5 days, 2 weeks, and 4 weeks postoperatively. Profiles of these values were plotted over the 4-week postoperative time course for each group of patients. Patients undergoing hepatic lobectomy showed a characteristic laboratory value profile. PT elevated within 48 hours to a mean high of 16.0 seconds, then returned to normal by postoperative day 4. Partial thromboplastin time levels remained normal throughout the entire perioperative course. Total bilirubin rose slightly, to a mean high of 2.6 mg/100 cc, then returned to normal by postoperative day (POD) 14. Parenchymal liver enzymes aspartate transaminase and LDH rose abruptly to very high levels, then returned abruptly to normal (by POD 5). TP and A both fell to approximately 50 per cent of normal, gradually rising to normal by POD 14. Glucose rose to a mean high of 199 mg/100 cc within the first 5 days, then returned to normal by POD 7. Alkaline phosphatase remained normal initially, then showed a progressive rise to a high of 288 mg/100 cc on POD 14. Patients undergoing wedge resections did not show the same changes in total serum bilirubin, but showed similar trends in all other tests, although the magnitude of these changes was smaller. TP and A levels fell acutely after resection, then began a slow rise toward normal by POD 21. TP and A profiles were similar for both lobectomy patients and those undergoing wedge resection. The only tests that may have altered clinical management were the PT and total bilirubin. Patients undergoing major hepatic resection have characteristic postoperative profiles of liver enzymes and liver function tests. These laboratory profiles differ with the extent of hepatic resection. The profiles reflect changes in volume status, parenchymal liver destruction, transient hepatic insufficiency, and postoperative hepatic regeneration. However, except possibly for PT and bilirubin, the routine use of these tests is not recommended, given that the results do not alter clinical management.