QS307 - Apixaban as Chemoprophylaxis After Colorectal Surgery: A Pilot Case-Control Study

Tuesday, June 4, 2024

8:27 AM – 8:30 AM ET, USA

Location: Room 327

Quick Shot Presenter(s)

Julia L. Nugent, MD

Fellow
University of Wisconsin-Madison
Madison, WI, United States

All relevant financial disclosures have been managed and will be listed below.
This individual has no financial relationships with ineligible companies.

Author(s)

EC

Evie Carchman, MD

Associate Professor
University of Wisconsin-Madison
Madison, Wisconsin, United States

Disclosure information not submitted.
AD

Ana De Roo, MD MSc

Assistant Professor
University of Wisconsin-Madison
Madison, Wisconsin, United States

Disclosure information not submitted.
Dana M. Hayden, MD, MPH

Professor
University of Wisconsin-Madison
University of Wisconsin-Madison
Madison, Wisconsin, United States

All relevant financial disclosures have been managed and will be listed below.
This individual has no financial relationships with ineligible companies.
Charles P. Heise, MD, FACS, FASCRS

Professor of Surgery
University of Wisconsin, Madison
Madison, Wisconsin, United States

Disclosure information not submitted.
EL

Elise Lawson, MD, MSHS

Associate Professor of Surgery
University of Wisconsin School of Medicine and Public Health
Madison, Wisconsin, United States

Disclosure information not submitted.
CS

Cristina B. Sanger, MD

Associate Professor of Surgery
University of Wisconsin-Madison
Madison, Wisconsin, United States

All relevant financial disclosures have been managed and will be listed below.
This individual has no financial relationships with ineligible companies.
BT

Beth E. Thompson, BS, RT(R)(CT)

Colorectal Database Manager
University of Wisconsin School of Medicine & Public Health, Madison, WI
Verona, Wisconsin, United States

Disclosure information not submitted.

Senior Author(s)

Julia R. Berian, MD, MS (she/her/hers)

Assistant Professor of Surgery
University of Wisconsin-Madison
University of Wiscosin - Madison
Madison, Wisconsin, United States

All relevant financial disclosures have been managed and will be listed below.
This individual has no financial relationships with ineligible companies.

Purpose/Background: Colorectal cancer and inflammatory bowel disease (IBD) have been shown to be prothrombogenic diseases, and following major abdominal surgery, rates of venous thromboembolism (VTE) may be as high as 13%. Consideration for extended VTE chemoprophylaxis after colorectal surgery for cancer and IBD is recommended in the American Society of Colon and Rectal Surgeons practice guidelines. Extended chemoprophylaxis is typically accomplished with subcutaneous enoxaparin. However, enoxaparin is often costly for patients, or undesirable due to the need for self-injection. Apixaban is an oral direct factor Xa inhibitor and has been reported to be noninferior to enoxaparin for chemoprophylaxis after surgery for malignant gynecologic neoplasms. Our institution implemented utilization of apixaban for extended chemoprophylaxis when enoxaparin was found to be too costly. We aim to compare readmission, bleeding, and VTE rates for patients discharged with apixaban compared to a matched control cohort of patients discharged with enoxaparin.

Methods/Interventions: Patients who underwent diversion, colectomy, or proctectomy for IBD or cancer and were discharged on apixaban in 2023 were identified by an institutional database supplemented with chart review. A control cohort prescribed prophylactic enoxaparin was matched by age, sex, ASA class, BMI, diagnosis (malignancy, ulcerative colitis, Crohn’s disease), and surgery type (laparoscopic versus open, pelvic versus non-pelvic resection). The primary outcome was 30-day readmission rate. Secondary outcomes were 30-day bleeding events and 30-day VTE events. Results are expressed as mean ± SEM.

Results/Outcomes: Thirty-two patients were included in this study (16 in apixaban cohort, 16 in enoxaparin cohort). Each group was 50% male; mean age was 65 ± 3 years and mean BMI was 28 ± 1 kg/m2. 72% of patients had colorectal or anal cancer, 16% had ulcerative colitis, and 19% had Crohn’s disease (one patient in each cohort had an overlapping IBD and cancer diagnosis). Most operations were non-pelvic resections (84%) with 50% performed laparoscopically and 50% open. There were no readmissions within 30 days of surgery in either cohort. There were no noted VTE events or major bleeding events within 30 days after surgery in either cohort. One patient discontinued apixaban on postoperative day 11 due to bright red blood per rectum without associated anemia.

Conclusion/Discussion: This single-institution, retrospective, matched case-control study provides preliminary data to support the use of apixaban compared to enoxaparin for extended chemoprophylaxis after major abdominal colorectal surgery for cancer or IBD. There were no 30-day readmissions postoperatively and no major bleeding or VTE events in either cohort. This study is limited by a small sample size and its retrospective nature. Given low event rates, we are unable to assess differences with statistical significance. However, in this preliminary analysis we are able to demonstrate acceptable safety and efficacy in a small cohort. Future work will aim to expand sample size as well as investigate differences in insurance coverage, cost, and patient satisfaction and adherence with use of prophylactic apixaban after surgery.