Butterfly-like Knotting of a Lumbar Epidural Catheter

We report a female patient with osteoarthritis of both knees, who was scheduled for bilateral total knee arthroplasty under spinal and lumbar (L) epidural anesthesia. An epidural catheter was inserted at the L3-L4 intervertebral space and threaded 9 cm cephalad beyond the tip of the Tuohy needle. Attempts to remove the catheter met with resistance. Because changing the patient's position failed to relieve the resistance, we suspected that the epidural catheter had kinked. After explaining to the patient and her family the need for surgical removal of the catheter and its associated risks, the catheter was successfully removed by an orthopedist by laminectomy. A butterfly-like knot was found about 5 cm away from the tip of the epidural catheter. She experienced no complications during surgery and no neurological sequelae were observed during her stay in hospital.