Aim
Based on three randomised controlled trials performed more than a decade ago, several national guidelines recommend prolonged venous thromboprophylaxis for 28 days following elective surgery for colon cancer. None of these studies were conducted within enhanced recovery after surgery setting. Newer studies indicate that prolonged prophylaxis might not be necessary with enhanced recovery after surgery. We aimed to provide further evidence to this unresolved discussion.

Method
Retrospective study of patients undergoing elective surgery for colon cancer stage I-III with enhanced recovery after surgery in the Capital Region of Denmark from 2014 to 2017. Patients were excluded if discharged on postoperative day 28 or later, dying before discharge, undergoing concomitant rectum resection, or discharged with vitamin K antagonists, direct-oral anticoagulants, or low molecular weight heparin treatment. All patients received only low-dose low molecular weight heparin as prophylaxis during their admission.

The primary endpoint was symptomatic lower limb deep venous thrombosis or pulmonary embolism diagnosed within 60 days postoperatively.

Results
Out of the included population of 1806 patients, only three experienced a symptomatic venous thromboembolic event; none was fatal. Two had pulmonary embolism associated with pneumonia, while one patient was diagnosed with lower limb deep venous thrombosis at postoperative day 15 after an uncomplicated course with first discharge at postoperative day 2.

Conclusion
The risk of symptomatic venous thromboembolism after elective surgery for colon cancer with enhanced recovery after surgery seems negligible even without prolonged prophylaxis. The current guidelines need to be reconsidered.