Readmission Rates Due To Venous Thromboembolism In Cancer Patients After Abdominopelvic Surgery
Authors: Klimowicz White Christine , Langholtz Jessica , Burns Zackory T. , Sullivan Susan Kruse , Sallee Kimberly , Henry David H. 
Published: October 2019

Abstract
In current medical practice, duration of hospitalizations and readmission rates have become focal points, often determining hospital reimbursements and acting as a measure of the quality of patient care. Oncology patients and patients undergoing major surgery have an increased risk for venous thromboembolism (VTE), a serious clinical problem with potentially fatal and costly consequences. It is the most common cause of death in oncology patients within the first 30 days post-operatively, and the second most common cause of death in cancer patients after cancer itself.
The national guidelines currently recommend thromboprophylaxis for cancer patients undergoing major surgery for at least 7 to 10 days postoperatively with either unfractionated heparin (UFH) or low molecular weight heparin (LMWH). Cancer patients undergoing major abdominopelvic surgery with high-risk features should have extended prophylaxis for 4 weeks.
To study this problem, we examined the incidence of VTE in cancer patients after abdominopelvic surgery. The primary study outcome was to define the most common causes of 30-day readmission rates. Secondary outcomes were to determine if VTE prophylaxis was prescribed for this patient population upon discharge, to assess compliance with VTE guidelines, and to agree or disagree with these guidelines.
We identified 6949 patients who underwent abdominopelvic surgeries at Pennsylvania Hospital between 2010 and 2012. Patients were excluded if they did not have a proven abdominopelvic malignancy or if the surgery was an outpatient procedure. During hospitalization, 4 patients died and were excluded, resulting in 264 patients for final analysis. Electronic medical records were used to collect patient demographics and disease characteristics. We reviewed inpatient and outpatient records to account for hospital readmissions.
The median patient age was 67 years, 48.5% were male, and 42% had metastatic disease. The most common malignancy locations were colorectal (44%) and pancreas (11%).
During hospitalization, 99% (262/264) received perioperative anticoagulation for a median of 5.5 days. Upon discharge, 14 patients (5%) received anticoagulation with LMWH or Coumadin, but only 2 received it primarily for VTE prevention. Patients were also discharged on aspirin and/or clopidogrel (Table 1).
Within 30 days of discharge, 35 patients (13%) were readmitted to hospital after a median of 7 days. Fourteen patients were lost to follow up. Reasons for readmission were abdominal symptoms (11), post-operative complications or surgical problems (11), infectious causes (8), cardiopulmonary symptoms (6), and electrolyte disturbances (2). Three patients were readmitted with multiple presenting symptoms, and 2 had planned surgeries.
Two patients were readmitted with a VTE, but 1 VTE was previously known and excluded. The remaining patient was readmitted 4 days post-discharge for chest pain, later found to be a symptomatic pulmonary embolism.
As current guidelines recommend extended 4-week thromboprophylaxis in oncology patients after major abdominopelvic surgery, we anticipated that VTE as cause of 30-day readmission would be much more common. In our study, 95% were not discharged from the hospital on anticoagulation, which shows that the guidelines are not routinely followed in this surgical setting. Only 1 patient, not discharged on anticoagulation, was readmitted within 30 days for symptomatic VTE, indicating that the incidence of symptomatic VTE in post-operative oncology patients may not be as high as previously suggested. Furthermore, these recommendations are primarily based on decreased incidence of asymptomatic VTE, despite a lack of clear evidence proving a benefit to the patient in reducing asymptomatic VTE and limited data assessing this recommendation for those with symptomatic VTE. Extended anticoagulation may also lead to increased costs and potential for bleeding. Due to the low incidence of symptomatic VTE in our findings, we recommend that further multicenter studies will need to be conducted to better quantify the need for extended VTE prophylaxis in post-operative patients with abdominopelvic malignancies.

Disclosures:
No relevant conflicts of interest to declare.