Wertigkeit der Luftprobe nach (Stapler-)Anastomosen bei kolorektalen Anastomosen

Background Anastomotic leakage is still one of the most serious complications after colorectal surgery (Buchs et al. 2008). The air leak test is the most frequently used intraoperative test to check the tightness of a new anastomosis and to identify a leaky suture (Nachiappan et al. 2014). To date, the significance of the air leak test regarding the risk for anastomotic leakage has been rarely considered. Therefore we have decided to perform this research to determine the effec-tiveness of the air leak test and in addition possible risk factors for anastomotic leakage. Method Data from all patients who underwent surgery for colorectal cancer between 2009 and 2014 at the Marburg Universitiy Medical Centre were analyzed. 237 of the 588 data sets fulfilled the criteria for inclusion. The factors age, sex, location of colorectal cancer, performed surgical intervention, laparoscopic assisted surgery vs. open surgery, use of a stapler, result of the air leak test, postoperative anastomotic leakage, grade of anastomotic leakage, duration of opera-tion, emerceny vs. elective surgery, anesthesiological parameters such as intraoperative fluid management, intraoperative blood transfusion and intraoperatives catecholamines and pre-operative factors such as alcohol and nicotine abuse, diabetes mellitus, body mass index, ASA-score and neoadjuvant radiochemotherapy were collected. Results The air leak test was performed in all of the 237 patients. Anastomotic leakage occured in 42 (17.7%) patients. The air leak test proved to be intraoperative tight (negative test result) in 224 (94.5%) patients. The test showed leaks in 13 (5.5%) patients (positive test result). 39 (17.42%) of 224 patients with negative test results developed an anastomotic leak. Of the 13 patients with positive test results an anastomotic leakage was observed in 3 (23.11%) pa-tients. The p-value of the correlation between the result of the air leak test and the incidence of anastmotic leak was 0.7065; thus the difference of anastomotic leak rate between patients with negative and patients with positive test results were statistically not significant. The univariate analysis of risk factors showed no significance. 85 Conclusion Is a leak observed during the intraoperative test and reinforcing sutures are made, the risk for developing a leakage is equal to the risk of leakage after negative test result in the first place. This suggests that reinforcing sutures of an anastomosis after a postive air leak test will be adequate and reconstruction of the anastomosis won´t be necessary. Due to the fact that the analysis of the single risk factors showed no significance and the risk for anastomotic leakage is possibly affected by an indivual combination of risk factors, the risk stays statistically in-calculable. The technical correctness in performing an anastomosis and the associated sur-geon´s surgical skills could be the most important single factors. The air leak test is certainly informative in evaluating the technical correctness of the anasto-mosis. Since the risk for anastomotic leak is possibly influenced by other circumstances, the air leak test is limited in predicting the real risk for anastomotic leakage. Thus the effective-ness of air leak test seems to be limited.