To Örebro University

Objective: The aim of the study was to find laboratory samples for early diagnosis of anastomotic leak.

Summary background data: Anastomotic leakage after rectal cancer surgery is a severe complication with high mortality. Outcome is highly dependent on early diagnosis.

Methods: 29 patients were investigated postoperatively after having undergone low anterior resection due to cancer recti. Patient outcomes were divided into three groups: Anastomotic leak in 7 patients, other complications in 9 patients and 13 patients who were free of complications. Patients were monitored every 6^th hour with blood and intraperitoneal samples in order to identify laboratory markers for early detection of anastomotic leakage. An anastomotic leak index was created, a scoring system where points count for values higher than reference values of CRP and interleukin 6 in blood and intraperitoneal lactate, lactate/pyruvate ratio and interleukin 6 were measured at 18, 24, 42 and 48 hours postoperatively.

Results: Significant differences between groups were found regarding CRP, Interleukin 6, fibrinogen and D-dimer in blood. Intraperitoneal differences were found not only in lactate and lactate/pyruvate ratio measured by microdialysis, significant differences in interleukin 6, interleukin 10 and tumour necrosis factor-α could also be demonstrated between the groups. The anastomotic leak index had a sensitivity and specificity of 86% (p=0.0007).

Conclusions: The most important factor was time after operation. No laboratory parameter in itself could predict an anastomotic leak but the anastomotic leak index was a useful tool in the monitoring and assessment of clinical outcome.

Mini abstract: Patients with anastomotic leak after rectal surgery were monitored with higher intraperitoneal cytokines and lactate/pyruvate ratio. The results suggest intraperitoneal microdialysis combined with blood samples of CRP and IL 6 as a feasible method for early diagnosis of anastomotic leak.