Imaging Guidance for Thoracic Epidural Catheter Placement
With epidural analgesia as a part of many enhanced surgical recovery protocols, there is increasing realization that the traditional palpation and loss-of-resistance method for placement of a catheter in the epidural space has a substantial failure rate.1 In response, ultrasound guidance to assist with identification of the lumbar epidural space for placement of a lumbar epidural catheter has seen increasing use. Tawfik et al2 recently reported in this journal their results from a randomized trial on use of ultrasound to assist with identification of the epidural space in parturients. An accompanying editorial provided an excellent perspective on the topic.3 Missing from this and almost all investigations on use of ultrasound to facilitate lumbar epidural catheter placement is a discussion of imaging assistance with the technically more challenging placement of thoracic epidural catheters. Since 2010, we have routinely used fluoroscopy to place epidural catheters that will be used for non-obstetric postoperative analgesia. With this approach, our failure rate for thoracic epidural catheters (defined as unable to obtain loss-of-resistance, nonfunctioning catheter, catheter dislodgement, and leakage) went from 25% to 2%.4 Use of fluoroscopy may, at first, seem to represent a substantial, even insurmountable investment of resources. In reality, any additional resource investment is small and attended by several benefits. The equipment commitment includes availability of a C-arm (already available in almost all operating areas) and an x-ray–compatible table. From a training standpoint, interpretation of the images obtained is straightforward and does not require specialized training. Finally, since we sedate our patients in the prone position during catheter placement, a trained sedation nurse (also employed in most surgical centers) cares for the patient during the procedure. More importantly, several benefits accrue from this approach including:
Epidural analgesia for major abdominal and thoracic surgery continues to be an important part of the perioperative care plan for complex surgical patients. In these settings, it has been associated with significantly improved clinical outcome and cost benefits. The emerging use of fluoroscopy for thoracic epidural catheter placement could play an important role in caring for these surgical patients.