Purpose: Venous thromboembolic (VTE) conditions such as deep venous thrombosis (DVT) and pulmonary embolism (PE) can be a major source of morbidity and mortality in colorectal surgical patients. Risk stratification tools which aid in the choice of mechanical and pharmacologic prophylaxis include many risk factors; however, emergent surgery has not been identified as a specific risk factor for the development of VTE. The purpose of this study was to utilize the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) Participant Use Data File (PUF) to evaluate the association between emergent colorectal surgery and the incidence of VTE. Methods: The 2007 ACS-NSQIP PUF (consisting of 152,490 locked and de-identified cases from 2005-6) was queried by ICD-9 code for cases of colon (153) or rectal (154) cancer, diverticulosis/diverticulitis (562), regional enteritis (555) or ulcerative colitis (556). The 30-day incidence of DVT and/or PE was compared between emergent versus non-emergent cases using multinomial logistic regression. This analysis was repeated to control for known risk factors for VTE such as age, immobility, malignancy, chemotherapy, radiation therapy, smoking, pregnancy, thrombophilia, etc.Results: A total of 5,342 cancer and 3,418 diverticulitis and inflammatory bowel disease cases were identified. Age was statistically higher (p<0.001) in emergent versus non-emergent cases for both malignant: 70±14.4 years vs. 66±13.8 and benign: 60±17.3 vs. 53±15.8. Sex was not statistically different between groups. When controlled for weighted risk factors commonly used to stratify patients for VTE prophylaxis, patients who underwent emergent surgery were at increased risk for DVT and/or PE for both malignant and benign cases (table). Conclusion: Patients undergoing emergent colorectal surgery for both benign and malignant disease are at significantly higher risk for VTE. Unless contraindicated, VTE prophylaxis should be administered in the perioperative period in patients undergoing emergent colorectal surgery.

	Emergent		Non-Emergent
	Total	VTE (%)	Total	VTE (%)
Malignant	273	11 (4.03%)	5,069	88 (1.74%)	p<0.001, OR 1.20*
Benign	468	20 (4.27%)	2,950	55 (1.86%)	p<0.001, OR 1.20*

* Odds Ratio per one unit weighted increase in risk factors