Defining the Economic Burden of Perioperative Venous Thromboembolism in Inflammatory Bowel Disease in the United States

Timing and Location of Venous Thromboembolisms After Surgery for Inflammatory Bowel Disease

INTRODUCTION

Patients with inflammatory bowel disease are reported to be at elevated risk for postoperative venous thromboembolism (VTE). The rate and location of these VTE complications is unclear.

METHODS

Patients with ulcerative colitis (UC) or Crohn's disease (CD) undergoing intestinal operations between January 2006 and March 2021 were identified from the medical record at a single institution. The overall incidence of VTEs and their anatomic location were determined to 90 days postoperatively.

RESULTS

In 2716 operations in patients with UC, VTE prevalence was 1.95% at 1-30 days, 0.74% at 31-60 days, and 0.48% at 90 days (P < 0.0001). Seventy two percent of VTEs within the first 30 days were in the portomesenteric system, and this remained the location for the majority of VTE events at 31-60 and 61-90 days postoperatively. In the first 30 days, proctectomies had the highest incidence of VTEs (2.5%) in patients with UC. In 2921 operations in patients with CD, VTE prevalence was 1.43%, 0.55%, and 0.41% at 1-30 days, 31-60 days, and 61-90 days, respectively (P < 0.0001). Portomesenteric VTEs accounted for 31% of all VTEs within 30 days postoperatively. In the first 30 days, total abdominal colectomies had the highest incidence of VTEs (2.5%) in patients with CD.

CONCLUSIONS

The majority of VTEs within 90 days of surgery for UC and Crohn's are diagnosed within the first 30 days. The risk of a VTE varies by the extent of the operation performed, with portomesenteric VTE representing a substantial proportion of events.

Postoperative Venous Thromboembolism in Colon and Rectal Cancer: Do Tumor Location and Operation Matter?

BACKGROUND

Existing venous thromboembolism (VTE) risk scores help identify patients at increased risk of postoperative VTE who warrant extended prophylaxis in the first 30 days. However, these methods do not address factors unique to colorectal surgery, wherein the tumor location and operation performed vary widely. VTE risk may extend past 30 days. Therefore, we aimed to determine the roles of tumor location and operation in VTE development and evaluate VTE incidence through 90 days postoperatively.

STUDY DESIGN

Adult patients undergoing surgery for colorectal cancer between January 1, 2005, and December 31, 2021, at a single institution were identified. Patients were then stratified by cancer location and by operative extent. VTEs were identified using diagnosis codes in the electronic medical record and consisted of extremity deep venous thromboses, portomesenteric venous thromboses, and pulmonary emboli.

RESULTS

A total of 6,844 operations were identified (72% segmental colectomy, 22% proctectomy, 6% total (procto)colectomy), and tumor location was most commonly in the ascending colon (32%), followed by the rectum (31%), with other locations less common (sigmoid 16%, rectosigmoid junction 9%, transverse colon 7%, descending colon 5%). The cumulative incidence of any VTE was 3.1% at 90 days with a relatively steady increase across the entire 90-day interval. Extremity deep venous thromboses were the most common VTE type, accounting for 37% of events, and pulmonary emboli and portomesenteric venous thromboses made up 33% and 30% of events, respectively. More distal tumor locations and more anatomically extensive operations had higher VTE rates.

CONCLUSIONS

When considering extended VTE prophylaxis after colorectal surgery, clinicians should account for the operation performed and the location of the tumor. Further study is necessary to determine the optimal length of VTE prophylaxis in high-risk individuals.

Cost-Effectiveness of Aspirin for Extended Venous Thromboembolism Prophylaxis After Major Surgery for Inflammatory Bowel Disease

BACKGROUND AND PURPOSE

Venous thromboembolism extended prophylaxis after inflammatory bowel disease surgery remains controversial. The purpose of this study was to evaluate if adopting an aspirin-based prophylaxis strategy may address current cost-effectiveness limitations.

METHODS

A decision analysis model was used to compare costs and outcomes of a reference case patient undergoing inflammatory bowel disease-associated colorectal surgery considered for post-discharge thromboembolism prophylaxis. Low-dose aspirin was compared to an enoxaparin regimen as well as no prophylaxis. Source estimates were obtained from aggregated existing literature. Secondary analysis included out-of-pocket costs. A 10,000-simulation Monte Carlo probabilistic sensitivity analysis accounted for uncertainty in model estimates.

RESULTS

An enoxaparin-based regimen compared to aspirin demonstrated an unfavorable incremental cost-effectiveness ratio of $908,268 per quality-adjusted life year. Sensitivity analysis supported this finding in > 75% of simulated cases; scenarios favoring enoxaparin included those with > 4% post-discharge event rates. Aspirin versus no prophylaxis demonstrated a favorable ratio of $106,601 per quality-adjusted life year. Findings were vulnerable to a post-discharge thromboembolism rate < 1%, aspirin-associated bleeding rate > 1%, median hospital costs of bleeding > 3 × , and decreased efficacy of aspirin (RR > 0.75). The average out-of-pocket cost of choosing an aspirin ePpx strategy increased by $54 per patient versus $708 per patient with enoxaparin.

CONCLUSIONS

Low-dose aspirin extended prophylaxis following inflammatory bowel disease surgery has a favorable cost-safety profile and may be an attractive alternative approach.