eP379 - Venous Thromboembolism in Pelvic Exenteration Patients

Purpose/Background: Pelvic exenteration is a complex surgical intervention that involves multi-visceral resection of organs involved mostly by malignancies. These surgeries are known to have long operative times as well as higher morbidity and mortality postoperatively.

Postoperative venous thromboembolism (VTE), including deep venous thromboses (DVT) and pulmonary embolism (PE), is a complication that can increase the overall morbidity and mortality of patients. Many studies have shown risk factors that increase these rates, including malignancy and abdominal pelvic surgery. Previous studies have shown higher rates of VTE in patients undergoing colon and rectal surgery due to the higher number of risk factors.

Previous studies have looked at morbidity, mortality and outcomes associated with pelvic exenteration, or VTE in the colon and rectal surgery population undergoing various procedures. There is a relative scarcity of studies that specifically focus on the risk of VTE after pelvic exenteration using large databases in the United States.

This study aims to assess the procedure specific incidence and risk factors of VTE in patients undergoing pelvic exenteration.Methods/Interventions: The American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) database was queried from January 1 to December 31, 2021. We included patients who had pelvic exenteration for the diagnosis of malignant tumors of the rectum, bladder or pelvic organs. Study patients were identified based on the Current Procedural Terminology (CPT) codes: 45126, 51597, and 58240.

Perioperative factors analyzed included patient characteristics (age, sex), smoking history, American Society of Anesthesiologists (ASA) class, body mass index (BMI), disseminated cancer, bleeding disorder, and operative time. The rate of postoperative VTE for up 30-days was assessed. Multivariate regression analysis was performed using Microsoft® Excel.Results/Outcomes: 406 patients underwent pelvic exenteration, 5 were excluded from this study as there were null data points for some variables. Of the remaining 401 patients, the mean age was 63.8 years (range: 25-90). 167 (41.6%) were male. 285 (71.1%) patients had an ASA class of 3. 150 patients had a diagnosis of malignant neoplasm of the colon or rectum (37.4%), 160 had malignant neoplasm of the bladder (39.9%), and 4 had a gynecological malignancy (1.0%) and the remaining had a diagnosis not falling into the previous 3 categories.

10 patients had a diagnosis of PE (2.5%), 12 had a diagnosis of DVT (3.0%), with a total VTE rate of 5.5% (n=22) in this patient population. Average operative time for the entire cohort was 416.9 minutes.

The results of the multivariate analysis show that operative time in pelvic exenteration was an independent predictor for VTE (p=0.03).Conclusion/

Discussion: This study assessed the incidence of VTE in patients undergoing multivisceral organ resection from the NSQIP database and related risk factors of postoperative VTE. Analysis of the 2021 data identified a 5.5% incidence of VTE in this population, which is more than twice the risk of VTE reported for colorectal cancer patients. Multivariate regression identified longer operative times as an independent risk factor for VTE in patients undergoing pelvic exenteration. The high risk of VTE associated with this specific extensive pelvic colorectal surgery suggests that enhanced attention is required with regard to compliance with mechanical and chemical prophylactic measures perioperatively to minimize associated morbidity and mortality.Table 1Table 2Table 3