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Correspondence  |   September 1999
An Unusual Case of Epidural Catheter Obstruction 
Author Notes
  • Resident in Anesthesiology
  • Staff Anesthesiologist and Intensivist
  • Department of Anesthesiology and Critical Care
  • Beth Israel Deaconess Medical Center
  • Boston, Massachusetts 02215
Article Information
Correspondence
Correspondence   |   September 1999
An Unusual Case of Epidural Catheter Obstruction 
Anesthesiology 9 1999, Vol.91, 895. doi:
Anesthesiology 9 1999, Vol.91, 895. doi:
To the Editor:—
A 48-year-old man presented for a colostomy take-down. His medical history was significant for Crohn's disease, necessitating colon resection and colostomy. Combined epidural–general anesthesia was planned.
After achieving intravenous access, localization of the epidural space was achieved via  the L1–L2 interspace with the patient in the sitting position. A Perifix Continuous Anesthesia kit was used (B. Braun Medical Inc., Bethlehem, PA) A Tuohy–Schliff epidural needle (18-gauge × 10 cm) was placed in the epidural space without difficulty using the loss-of-resistance-to-injection-air technique. A radiopaque polyamide epidural catheter was inserted through the epidural needle. After the removal of the epidural needle over the catheter, a screw-cap connector was fixed to the distal end of the epidural catheter in the usual fashion.
It was then observed that injection of the test dose via  the catheter was impossible. Incremental withdrawal of the catheter did not correct this situation. The epidural catheter was eventually withdrawn completely. Subsequent attempts to flush the catheter proved futile. Close scrutiny of the epidural catheter assembly unit showed that the screw-cap catheter connector revealed a complete absence of the lumen within it (fig. 1). It is interesting to note that a simple naked-eye examination of the epidural screw-cap connector would have been sufficient to avoid the need for a second attempt at epidural catheterization. This coupled with an “injection test” of the epidural catheter and epidural screw-cap connector assembly would eliminate several mishaps of this nature. 1 
Fig. 1. Screw cap connectors, (  left  ) without lumen, (  right  ) normal lumen, as indicated by the arrows. 
Fig. 1. Screw cap connectors, (  left  ) without lumen, (  right  ) normal lumen, as indicated by the arrows. 
Fig. 1. Screw cap connectors, (  left  ) without lumen, (  right  ) normal lumen, as indicated by the arrows. 
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Difficult or impossible injection via  the epidural catheter can be a result of several causes, resulting in mechanical obstruction of the epidural catheter at various levels. Apart from accidental kinking, knotting, axial torsion, and malposition of the catheter, occasional manufacturing defects of the catheter (e.g.  , catheter without terminal helical “eyes”2) can lead to this problem. As far as we are aware, this is the first report of such a manufacturing defect of the screw-cap connector.
References 
References 
Albright GA: Anesthesia in obstetrics, Maternal, fetal and neonatal aspects. Menlo Park, Addison-Wesley Publishing, 1978, pp 228–9
Husemeyer RP: A defective epidural cannula. Anaesthesia 1980; 35 (9): 922
Fig. 1. Screw cap connectors, (  left  ) without lumen, (  right  ) normal lumen, as indicated by the arrows. 
Fig. 1. Screw cap connectors, (  left  ) without lumen, (  right  ) normal lumen, as indicated by the arrows. 
Fig. 1. Screw cap connectors, (  left  ) without lumen, (  right  ) normal lumen, as indicated by the arrows. 
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