Abstract: BACKGROUND: Lower extremity deep vein thrombosis is a catastrophic complication after lumbar spine fusion, and previous studies have shown that some patients, such as those with prosthetic arthroplasty and abdominal surgeries, suffer from a combination of preoperative anemia, which predisposes them to postoperative deep vein thrombosis of the lower extremities. However, whether preoperative anemia increases the risk of lower extremity deep vein thrombosis after lumbar spine fusion is unclear.
OBJECTIVE: To investigate the correlation between preoperative anemia and deep vein thrombosis of the lower extremities in patients after lumbar fusion.
METHODS: The clinical data of 1 178 patients who underwent lumbar spinal fusion treatment admitted to Third Affiliated Hospital of Anhui Medical University from January 2020 to December 2023 were retrospectively analyzed. According to whether or not the patients developed lower extremity deep vein thrombosis after the operation, and the patients were divided into the deep vein thrombosis group (ultrasound report suggestive of lower extremity deep vein thrombosis) and the non-deep vein thrombosis group (ultrasound report suggestive of no lower extremity deep vein thrombosis manifestation). The incidence of anemia was compared between the two groups. The risk factors for lower extremity deep vein thrombosis in patients undergoing lumbar spinal fusion were determined by univariate analysis and multifactorial logistic regression analysis.
RESULTS AND CONCLUSION: (1) Of the 1 178 patients, 43 (3.7%) were in the deep vein thrombosis group and 1 135 (96.4%) in the non-deep vein thrombosis group. (2) The prevalence of preoperative anemia in the deep vein thrombosis group was 32.6%, which was significantly higher than that in the non-deep vein thrombosis group, which was 10.9% (P < 0.05). (3) The results of univariate analysis showed significant differences in preoperative hemoglobin (P < 0.001), preoperative erythrocytes (P=0.028), D-dimer positivity (P=0.029), hypertension (P=0.019), the number of fused segments (P=0.023), anemia (P < 0.001), and transfusion (P=0.006) (P < 0.05). (4) Multifactorial analysis showed that preoperative anemia (OR=4.221, 95%CI:1.198-14.802, P=0.025) and D-dimer positivity (OR=2.023, 95%CI:1.065-3.844, P=0.031) were independent risk factors for the development of deep vein thrombosis after lumbar fusion. (5) It is indicated that patients undergoing elective lumbar fusion have a high incidence of preoperative anemia, and preoperative anemia is an independent risk factor for deep vein thrombosis after lumbar fusion. It is recommended that preoperative anemia should be actively managed and corrected before performing elective lumbar fusion to reduce the risk of deep vein thrombosis.

Key words: lumbar fusion, anemia, deep vein thrombosis of the lower extremities, lumbar disc herniation, univariate analysis