Removing knotted or stuck epidural catheters: a systematic review of case reports

The knotting or in vivo entrapment of epidural catheters is an uncommon but challenging issue for anesthesiologists. This study aimed to identify the possible causes behind entrapped epidural catheters and the effective methods for their removal.

A systematic review of relevant case reports and series was conducted using the patient/population, intervention, comparison and outcome framework and keywords such as "epidural," "catheter," "knotting," "stuck," "entrapped," and "entrapment." The Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement was followed, and the review protocol was registered with International Prospective Register for Systematic Reviews (CRD42021291266).

The analysis included 59 cases with a mean depth of catheter insertion from the skin of 11.825 cm and an average duration of 8.17 h for the detection of non-functioning catheters. In 27 cases (45.8%), a radiological knot was found, with an average length of 2.59 cm from the tip. The chi-squared test revealed a significant difference between the initial and final positions of catheter insertion (P = 0.049).

Deep insertion was the primary cause of epidural catheter entrapment. To remove the entrapped catheters, the lateral decubitus position should be attempted first, followed by the position used during insertion. Based on these findings, recommendations for the prevention and removal of entrapped catheters have been formulated.