Should venous thromboembolism chemoprophylaxis be utilized following spinal fusions?-a systematic review and literature-based decision analysis.

BACKGROUND

Venous thromboembolism (VTE) is a potentially life-threatening complication of spinal fusion. The balance of benefits and harms associated with chemoprophylaxis (CPX) remains uncertain in traditional studies. This study aimed to consolidate the available evidence and develop an exploratory model to quantify these competing outcomes.

METHODS

A thorough literature search was conducted across multiple databases, with study selection criteria including outcomes of interest for model parameters. Abstracts and full texts were screened independently by five reviewers, with data extracted to derive event probabilities and health utility values. Probabilities of outcomes included occurrence of post-operative VTE, deep vein thrombosis (DVT), pulmonary embolism (PE), and epidural hematoma. Utility assignments were derived from the literature with senior author review to ensure alignment.

RESULTS

A total of six studies with 2,023 patients were included in the final analysis. A clinical decision tree was generated using weighted averages of each outcome's probability and their corresponding utility values. We integrated branch-specific probabilities and utilities from the terminal nodes through each chance and decision node in a rollback analysis to calculate the overall expected utility for each strategy. The base-case analysis demonstrated that VTE CPX (n=1,049) yielded an expected utility of 0.79 compared to 0.88 for no VTE CPX (n=974). This pattern persisted across tested probability ranges (0.78-0.79 vs. 0.85-0.94) and tested utility ranges for 'epidural hematoma' and 'VTE without epidural hematoma' (0.78-0.79 vs. 0.87-0.89). However, varying the utility of 'no epidural hematoma and no VTE' produced overlapping ranges (0.40-0.97 vs. 0.45-0.97) and changed the preferred strategy at 0.8 and 0.9 utility values, respectively.

CONCLUSIONS

Based on heterogeneous outcome and health-utility estimates from the available literature, our exploratory decision-tree analysis found limited evidence of incremental benefit from VTE CPX after spinal fusion. This finding is sensitive to the model assumptions and should not be interpreted as definitive guidance for clinical practice.