Traction-Induced Avulsion of an Iliocaval Venous Branch During Multilevel OLIF for Degenerative Scoliosis: Case Report.

Adult degenerative scoliosis can be effectively treated with lateral or oblique lumbar interbody fusion (LLIF/OLIF), but vascular injury remains a rare and potentially catastrophic complication. We report the case of a 78-year-old woman with long-standing degenerative scoliosis who underwent multilevel OLIF from L2 to L5. During trial cage placement at L2-3, massive venous hemorrhage occurred, with an estimated blood loss of approximately 3750 mL. Intraoperative angiography showed no arterial extravasation, suggesting a venous source. The wound was packed, and the patient was stabilized with aggressive resuscitation. Reexploration 3 days later, performed with a vascular surgeon, identified an avulsed iliocaval venous branch at the anterior aspect of the L2 vertebral body. Hemostasis was achieved using a fibrin sealant patch and sustained compression. After recovery, staged posterior fixation was completed without further complication. The patient recovered without neurologic deficit and maintained satisfactory alignment at follow-up. This case highlights a rare indirect vascular injury mechanism during deformity correction, likely caused by traction on a stiff iliocaval venous branch during multilevel distraction. Careful preoperative vascular assessment, gradual disc-space distraction, readiness for staged management, and early vascular surgery involvement are essential to improve safety in complex OLIF procedures.