Antithrombotic drugs do not increase the risk of laparotomy for gastrointestinal cancer

Abstract

Abstract Background Some patients with gastrointestinal cancer requiring laparotomy take antithrombotic drugs (AT). However, safety of continuing or withdrawing AT before surgery is controversial. Purpose To investigate whether the use of AT increases intraoperative blood loss, perioperative thromboembolic event and mortality in patients undergoing laparotomy for gastrointestinal cancer. Methods In this retrospective study carried out from January 2016 to July 2019, we took a survey of laparotomy for gastrointestinal cancer in our hospital. AT was defined as aspirin, Adenosine-diphosphate receptor antagonists (ADPi), direct oral anticoagulants (DOAC) and vitamin K antagonists (VKA). Patients were stratified into three groups; non-AT (group N), continuing AT (group C) and withdrawing AT before surgery (group W). We investigated differences in risks of events, including intraoperative blood loss, thromboembolic events within 60 days including acute coronary syndrome, cerebral infarction and venous thromboembolism, and long-term mortality. We also compared between continuing and withdrawing AT after propensity score matching. Results A total of 335 patients (123 females, mean age 72.5±9.5 years) were enrolled and stratified into group C (n=24), W (n=45) and N (n=266). Mean follow-up period was 684±400 days. Aspirin was taken in twenty of group C and twenty-six of group W. ADPi was taken in ten and nine of each group respectively. DOAC was taken in three and six of each group respectively. And VKA was taken in one and eleven of each group respectively. Patients of group C had more coronary artery disease (75.0% of group C, 33.3% of group W and 2.3% of group N, p<0.001) and prior coronary stent implantation (54.2%, 20.0% and 0% of each group respectively, p<0.001). There was no significant difference in cancer site and cancer stage. There was no significant difference in intraoperative blood loss (median [interquartile] (mL): 102 [8, 154] in group C, 140 [50, 310] in group W, and 150 [53, 324] in group N (p=0.095). Thromboembolic event had occurred in 4.4% of group W and 1.9% of group N (p=NS). Long term mortality was 33.3% of group C, 20% of group W and 22.9% of group N (p=NS). Kaplan-Meier analysis showed there was also no significant difference of long-term mortality (Log-rank p=NS). In patients with AT, after propensity score matching, there was no significant difference in intraoperative blood loss (102 [8,154] vs. 88 [18,217], p=NS), thromboembolic event (none in both group) and long-term mortality (33.3% vs. 12.5%, p=0.168) between continuing AT and withdrawing AT. Kaplan-Meier analysis revealed there was a tendency of higher mortality in group C but not significant difference (Log-rank p=0.0643). Conclusion This study suggests that patients taking AT do not have significant higher risk of intraoperative blood loss, thromboembolic event and mortality in laparotomy of gastrointestinal cancer. Funding Acknowledgement Type of funding source: None