Finally, a More Balanced View of Venous Thromboembolism Prophylaxis

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.

Do Cost Limitations of Extended Prophylaxis After Surgery Apply to Ulcerative Colitis Patients?

BACKGROUND

Colorectal surgery patients with ulcerative colitis are at increased risk of postoperative venous thromboembolism. Extended prophylaxis for thromboembolism prevention has been used in colorectal surgery patients, but it has been criticized for its lack of cost-effectiveness. However, the cost-effectiveness of extended prophylaxis for postoperative ulcerative colitis patients may be unique.

OBJECTIVE

This study aimed to assess the cost-effectiveness of extended prophylaxis in postoperative ulcerative colitis patients.

DESIGN

A decision analysis compared costs and benefits in postoperative ulcerative colitis patients with and without extended prophylaxis over a lifetime horizon.

SETTING

Assumptions for decision analysis were identified from available literature for a typical ulcerative colitis patient's risk of thrombosis, age at surgery, type of thrombosis, prophylaxis risk reduction, bleeding complications, and mortality.

MAIN OUTCOME MEASURES

Costs ($) and benefits (quality-adjusted life year) reflected a societal perspective and were time-discounted at 3%. Costs and benefits were combined to produce the main outcome measure, the incremental cost-effectiveness ratio ($ per quality-adjusted life year). Multivariable probabilistic sensitivity analysis modeled uncertainty in probabilities, costs, and disutilities.

RESULTS

Using reference parameters, the individual expected societal total cost of care was $957 without and $1775 with prophylaxis (not cost-effective; $257,280 per quality-adjusted life year). Preventing a single mortality with prophylaxis would cost $5 million (number needed to treat: 6134 individuals). Adjusting across a range of scenarios upheld these conclusions 77% of the time. With further sensitivity testing, venous thromboembolism cumulative risk (>1.5%) and ePpx regimen pricing (<$299) were the 2 parameters most sensitive to uncertainty.

LIMITATIONS

Recommendations of decision analysis methodology are limited to group decision-making, not an individual risk profile.

CONCLUSION

Routine ePpx in postoperative ulcerative colitis patients is not cost-effective. This finding is sensitive to higher-than-average rates of venous thromboembolism and low-cost prophylaxis opportunities. See Video Abstract at http://links.lww.com/DCR/B818.

SE APLICAN LAS LIMITACIONES DE COSTOS DE LA PROFILAXIS PROLONGADA DESPUS DE LA CIRUGA A LOS PACIENTES CON COLITIS ULCEROSA

ANTECEDENTES:Los pacientes de cirugía colorrectal con colitis ulcerosa tienen un mayor riesgo de tromboembolismo venoso posoperatorio. La profilaxis extendida para la prevención de la tromboembolia se ha utilizado en pacientes con cirugía colorrectal, aunque ha sido criticada por su falta de rentabilidad. Sin embargo, la rentabilidad de la profilaxis prolongada para los pacientes posoperados con colitis ulcerosa puede ser aceptable.OBJETIVO:Evaluar la rentabilidad de la profilaxis prolongada en pacientes posoperados con colitis ulcerosa.DISEÑO:Un análisis de decisiones comparó los costos y beneficios en pacientes posoperados con colitis ulcerosa con y sin profilaxis prolongada de por vida.AJUSTE:Los supuestos para el análisis de decisiones se identificaron a partir de la literatura disponible para el riesgo de trombosis de un paciente con colitis ulcerosa típica, la edad al momento de la cirugía, el tipo de trombosis, la reducción del riesgo con profilaxis, las complicaciones hemorrágicas y la mortalidad.PRINCIPALES MEDIDAS DE RESULTADO:Los costos ($) y los beneficios (año de vida ajustado por calidad) reflejaron una perspectiva social y se descontaron en el tiempo al 3%. Los costos y los beneficios se combinaron para producir la principal medida de resultado, la relación costo-efectividad incremental ($ por año de vida ajustado por calidad). El análisis de sensibilidad probabilística multivariable modeló la incertidumbre en probabilidades, costos y desutilidades.RESULTADOS:Utilizando parámetros de referencia, el costo total de atención social esperado individual fue de $957 sin profilaxis y $1775 con profilaxis (no rentable; $257,280 por año de vida ajustado por calidad). La prevención de una sola mortalidad con profilaxis costaría $5.0 millones (número necesario a tratar: 6.134 personas). El ajuste en una variedad de escenarios mantuvo estas conclusiones el 77% de las veces. Con más pruebas de sensibilidad, el riesgo acumulado de TEV (>1,5%) y el precio del régimen de ePpx (<$299) fueron los dos parámetros más sensibles a la incertidumbre.LIMITACIONES:Las recomendaciones de la metodología de análisis de decisiones se limitan a la toma de decisiones en grupo, no a un perfil de riesgo individual.CONCLUSIÓN:La profilaxis extendida de rutina en pacientes posoperados con colitis ulcerosa no es rentable. Este hallazgo es sensible a tasas de TEV superiores al promedio y oportunidades de profilaxis de bajo costo. Consulted Video Resumen en http://links.lww.com/DCR/B818. (Traducción-Dr. Felipe Bellolio).