Deep vein thrombosis due to migrated graft bone after posterior lumbosacral interbody fusion. Case report.

The authors report the case of an 83-year-old woman with refractory sciatica attributable to isthmic spondylolisthesis at L-5. Her symptoms were successfully improved after posterior lumbar interbody fusion (PLIF) at L5-S1; however, notable swelling in her left leg suddenly developed 2 days postoperatively. Anterior migration of a fragment of bone graft was demonstrated on computed tomography scanning, and there was obvious occlusion of the left common iliac vein (CIV) on magnetic resonance venography. Ultrasonography revealed a thrombus in the left CIV at the site of compression. To prevent a pulmonary embolism during manipulation of the affected vein, an inferior vena cava filter was placed just before excision of the migrated bone fragment. The swelling in the patient's leg subsided quickly after the surgery, and she was treated with heparin and warfarin to prevent recurrent deep vein thrombosis (DVT). Six months after the second surgery, complete restoration of blood flow to the left CIV and no recurrence of DVT were demonstrated on magnetic resonance venography. Especially in elderly patients with degenerative disc disease, excessive curettage and impaction of disc materials during the PLIF procedure may cause migration of bone graft fragments. Surgeons should be aware of the possible vascular complications of PLIF.