Preoperative Hospitalization Is Independently Associated With Increased Risk for Venous Thromboembolism in Patients Undergoing Colorectal Surgery: A National Surgical Quality Improvement Program Database Study.

Abstract

An important factor in the pathophysiology of venous thromboembolism is blood stasis, thus, preoperative hospitalization length of stay may be contributory to risk. We assessed preoperative hospital length of stay as a risk factor for venous thromboembolism. We performed a retrospective review of patients who underwent colorectal operations using univariate and multivariable propensity score analyses. This study was conducted at a tertiary referral hospital. Data on patients was obtained from the American College of Surgeons National Surgical Quality Improvement Program 2005-2011 Participant Use Data Files. Short-term (30-day) postoperative venous thromboembolism was measured. Our analysis included 242,670 patients undergoing colorectal surgery (mean age, 60 years; 52.9% women); of these, 72,219 (29.9%) were hospitalized preoperatively. The overall rate of venous thromboembolism was 2.07% (1.4% deep vein thrombosis, 0.5% pulmonary embolism, and 0.2% both). On multivariable analysis, the most predictive independent risk factors for venous thromboembolism were return to the operating room (OR, 1.62 (95% CI, 1.44-1.81); p < 0.001) and chronic steroid use (OR, 1.59 (95% CI, 1.41-1.80); p < 0.001); preoperative hospitalization also independently predicted venous thromboembolism (OR, 1.39 (95% CI, 1.28-1.51); p < 0.001), whereas the use of laparoscopy was protective (OR, 0.75 (95% CI, 0.67-0.83); p < 0.001). Propensity score stratification (capped at 7 days, 100 strata, area under the curve = 0.73) indicated that each day of preoperative hospitalization increased the odds of venous thromboembolism (OR, 1.42 (95% CI, 1.32-1.53); p < 0.001). All of the analyses showed a dose-response relationship between preoperative lengths of stay and risk of postoperative venous thromboembolism (p < 0.001). Patients who experienced venous thromboembolism had a higher 30-day mortality rate (3.7% vs 8.9%; p < 0.001). This study has limited potential generalizability and a retrospective design. Preoperative hospitalization is an independent risk factor for venous thromboembolism and its associated increase in mortality after colorectal surgery, whereas laparoscopy is a strong protective variable. Further research into preoperative screening for highest-risk patients is indicated.