Special Poster Session 50th International Society for the Study of the Lumbar Spine Annual Meeting 2024

INTRODUCTION: In the context of increased longevity, the number of patients with symptomatic, degenerative spinal conditions related to spondylosis, lumbar stenosis, and instability is also increasing. Anterior approach lumbar spinal surgery may facilitate the utilization of intervertebral devices with larger endplate coverage and increased lordosis. Despite the advantages of the anterior approach lumbar spinal surgery, risks related to vascular injury in older patients have been described in the literature. The purpose of the current study was to investigate the impact of age on the incidence of vascular complications in a large series of patients undergoing anterior lumbar approach surgery.

METHODS: This was a retrospective cohort study of 751 consecutive patients who underwent stand-alone anterior lumbar interbody fusion procedures (ALIF), ALIF combined with posterior fusion or instrumentation, total disc replacement (TDR), or hybrid surgery (ALIF and TDR) for the treatment of degenerative spinal pathology at no more than 3 levels. Patients undergoing surgery for fracture, tumor, complex deformity, or involving a lateral approach were excluded. Charts were reviewed to collect general patient descriptive data, surgery details, intra-operative vascular injury, and post-operative vascular complications (deep vein thrombosis (DVT) and/or pulmonary embolism (PE)). Rates of vascular complications were compared across age groups divided by decade of age at the time of surgery. Data were also analyzed comparing the mean age of patients with no vascular complications to those in each of the vascular complication subgroups.

RESULTS: The overall mean age was 50.4 years (range 20 to 83 years). The majority of patients (53.1%) underwent combined ALIF/posterior surgery, 31.7% underwent TDR, 11.3% underwent ALIF, and the remaining patients underwent hybrid surgery. With respect to the number of levels operated: 468 were 1-level, 253 were 2-level, and 30 were 3-level. Mean estimated blood loss was 91.3 ml (range 10 to 2800 ml). A total of 15 patients, 2.0%, had vascular complications. There were 10 cases (1.3%) of intra-operative injury to iliac arteries or iliolumbar veins. The mean blood loss in these cases was 721 ml and all were successfully repaired intra-operatively.  Postoperatively, 6 patients, 0.8%, developed DVT and/or PE (one patient had both intra-operative and post-operative vascular complications). With respect to age, there were no significant differences in the rates of intra-operative, post-operative, or combined vascular complication rates with respect to age (Table 1; all p>0.38). Additionally, there were no statistically significant differences in the mean ages of patients with vs. those without vascular complications (Table 2; all p>0.17). Further analyses confirmed that the lack of relationship between age and vascular events could not be attributed  to the possible confounding factors of the number of levels operated or anterior only vs. anterior/posterior surgery being performed.

DISCUSSION: The overall incidence of vascular complications was 2.0%. No correlation between the risk of vascular complications and patient age was demonstrated. While there is generally increased concern for vascular complications in older patients undergoing anterior approach lumbar spine surgery, these data suggest that increased age is not necessarily a contraindication for this approach.