Entrapped Epidural Catheter Case

Removing an epidural catheter rarely poses any technical difficulty. Few anaesthesiologists or Advanced Practice Nurses (APNs) having expertise in surgical pain management have personal experience in dealing with epidural catheters that cannot be removed by gentle traction [1]. The cause and location of the epidural entrapment is seldom apparent and the optimum approach to its extraction while avoiding catheter breakage is not evident [1].


Introduction
Removing an epidural catheter rarely poses any technical difficulty. Few anaesthesiologists or Advanced Practice Nurses (APNs) having expertise in surgical pain management have personal experience in dealing with epidural catheters that cannot be removed by gentle traction [1]. The cause and location of the epidural entrapment is seldom apparent and the optimum approach to its extraction while avoiding catheter breakage is not evident [1].

Case Description
An 81-year-old male underwent lung, chest wall and liver resection for a recurrent lung carcinoma. The epidural was sited at a T 6 level intraoperatively by the surgeon through the surgical field. The depth of the epidural catheter was 10 cm. Anesthesia and surgery were uneventful and effective postoperative analgesia was achieved by patient controlled epidural analgesia with bupivacaine and hydromorphone for the first four postoperative days.
On the fifth post-operative day, the APS APN encountered significant resistance while trying to remove the epidural catheter. An anaesthesiologist confirmed that the catheter was trapped and could not be extracted despite firm traction while placing the patient in a variety of positions. The decision was made to leave the catheter in place and attempt its removal using a guide wire under fluoroscopy. While in the prone position the skin of the upper back was prepped and draped in a sterile fashion. The epidural catheter was cut and an 18" Mandrill wire was advanced through it under fluoroscopy until its tip was near but did not extend beyond the end of the epidural catheter. No knot or loop was observed. The wire and the intact epidural catheter were removed together without significant resistance. On subsequent visits, the epidural site remained free of inflammation.

Discussion
Catheter entrapment is known complication of epidural analgesia and may occur at the all levels of the epidural space [2]. Proposed management of the entrapped epidural catheter includes visualization of the catheter by fluoroscopy, CT or MRI and based on the imaging findings may require removal of the catheter surgically. Non-surgical options were described by [3] and include trying to remove the catheter while placing the patient in a variety of positions including the insertion, lateral decubitus, extreme flexion and extension positions and the injection of preservative-free normal saline through the catheter. These maneuvers were unsuccessful in our case. We had previous success in removing a trapped epidural catheter uneventfully by passing a wire through the catheter under fluoroscopy and so proceeded promptly to pursue this option again. In both cases the trapped catheters were removed easily and without complications while employing this technique. Although the using of a guide wire to identify an entrapped epidural catheter has been described previously, [4] to our knowledge, our case report is the first to demonstrate the utility of a guide wire for the non-surgical removal of trapped epidural catheters.
Renehan et al. [4] described the use of the guide wire to visualize a knot in their trapped epidural catheter with fluoroscopy, which was subsequently surgically removed. Our case demonstrates that a guide wire may be useful not only for visualization and defining the causes of entrapment but also as a tool to potentially remove the catheter without proceeding to surgical intervention [5,6].

Conclusion
Entrapped epidural catheters may be safely and easily removed using an 18" Mandrill wire.