Migration of a Nelaton Catheter Into the Pulmonary Artery During Spinal Surgery Requiring Surgical Removal: A Regrettable Case.

Perioperative complications in spinal surgery include dural injury, postoperative epidural hematoma, and surgical site infections. More severe complications involve paralysis, sensory deficits due to nerve injury, and bladder or bowel dysfunction. During fusion surgery, attention must also be paid to risks such as guide wire breakage, cage migration or dislodgement, and major vascular injury during intervertebral disc gauge placement. A common empirical practice during bone drilling with a high-speed drill involves placing a 15 mm segment of a Nelaton catheter over the tip of the suction tube to prevent damage to the tissue. This is referred to as a "Nelaton cover." We report a regrettable case in which a Nelaton cover became dislodged during lumbar disc curettage, subsequently migrating into the common iliac vein and leading to pulmonary artery embolism, which required surgical removal. The patient was a 71-year-old man with independent activities of daily living and a history of diabetes mellitus and lumbar disc herniation (L5/S1). He presented with lower back pain, bilateral lower extremity pain and numbness, and intermittent claudication that had persisted for one year. At presentation, there was no significant muscle weakness, but he experienced pain and numbness extending from the left buttock to the lateral aspect of the left lower leg. Lumbar MRI showed left L5 foraminal stenosis, and posterior lumbar decompression and fusion at L5/S1 was planned. During surgery, following L5 laminectomy, active bleeding was noted within the disc space during L5/S1 disc curettage. A venous injury on the ventral side of the disc was suspected. Hemostasis was attempted using a suction tube fitted with a Nelaton cover. However, after completing the hemostatic maneuver, the Nelaton cover was found to be missing and not visible in the surgical field. The operation proceeded, with disc cage and pedicle screw placement completed as planned. Postoperative lumbar X-ray revealed the Nelaton cover had likely migrated into the inferior vena cava at the L3/4 level. A postoperative CT scan confirmed its presence in the left pulmonary artery. Thoracic surgeons performed surgical removal. Fortunately, the patient showed no decline in pulmonary function, experienced improvement in bilateral leg numbness, and was discharged ambulatory with a modified Rankin Scale score of 1. In this case, bleeding during disc curettage was likely due to common iliac vein injury. During compression hemostasis using the suction tube with a Nelaton cover, the cover became detached and entered the venous circulation, ultimately resulting in pulmonary embolism. This case highlights the need for caution when managing bleeding near major vessels during spinal surgery and underscores the risk of using improvised tools such as Nelaton covers for hemostasis.