Visualization of a looped and knotted epidural catheter with a guidewire

Purpose: To describe the management of a looped and knotted epidural cathet er after analgesia for labour and delivery Clinical Features: Obstetrical epidural pain relief was provided for a 37-y r old woman in early labour. A 20-gauge Portex(R) catheter was inserted at the L2 - L3 interspace, Six centimetres of catheter was left in the epidura l space. After vaginal delivery the catheter could not be removed. The cath eter was left in situ for 24 hr. Repeated attempts at removal were again un successful. The epidural catheter was not visible with fluoroscopy and it w as impossible to inject radiopaque dye into the catheter. However, we succe ssfully advanced a 0.016 inch guidewire through the epidural catheter and r adiologically demonstrated a knot and part of a loop. The catheter was remo ved by an orthopedic surgeon using blunt dissection under local anesthetic from the soft tissue just lateral to the interspinous ligament. Conclusions: A knot can be a rare cause of a trapped epidural catheter. A s uggested approach to the trapped lumbar epidural catheter: 1) Gentle tracti on on the catheter with the patient in various positions and in various deg rees of lumbar flexion. 2) Test for catheter patency by injecting sterile, preservative-free normal saline through the catheter. 3) Radiological imagi ng to determine if a knot is present and to determine its location, using r adiopaque contrast for patent catheters or a guidewire for occluded cathete rs. 4) The approach to definitive management is based on the position of th e knot. This can range from excision under local anesthetic to consultation with a surgical specialty for more invasive retrieval.