Real-time ultrasound-guided mid-thoracic epidural access using a novel paramedian cross (PX) view and drip infusion technique: a brief technical report

Abstract

Background: Real-time ultrasound guidance (USG) has been applied for lower thoracic epidural access, but the more challenging mid-thoracic epidural (MTE) access remains underexplored. This report presents a technique of real-time US guidance with a novel paramedian cross view, termed "the PX view," for securing MTE catheters, along with an outcome analysis from a retrospective case series.

Methods: Medical records of patients who underwent USG-MTE catheter placement with the PX view and drip infusion technique from January to December 2022 were reviewed. All catheters were placed with patients in the prone position under mild to moderate procedural sedation. The process of acquiring the PX view, in-plane needling technique, and the use of drip infusion to identify loss of resistance were detailed. The incidence of successful PX view attainment, the number of attempts, redirections, failures, and any technique-related complications were recorded.

Results: Fifty-one patients underwent USG-MTE catheter attempts, (42 with median sternotomy, 3 fractured ribs, 3 upper abdominal laparotomies, 2 modified radical mastectomies, and 1 thoracotomy). A satisfactory PX view was obtained in all patients, and the epidural space was identified during the first needle entry in 49 cases, resulting in a 96% first-attempt success rate. Seven patients required needle redirections, while two patients needed a second needle entry. No technique-related complications were documented.

Conclusion: The combination of the PX view and the drip infusion method proved effective for real-time ultrasound-guided MTE catheter placement.

Keywords: REGIONAL ANESTHESIA; Treatment Outcome; Ultrasonography.

Figure 1. Showing the systematic scanning technique with probe position and corresponding sonoanatomy to be identified. *yellow star - represents the superior articular process of the T5 lamina. CTJ, costotransverse joint; SAP, superior articular process; SP, spinous process; TP, transverse process; USG, ultrasound guidance.

Figure 2. Image showing the probe position (A) and sonoanatomy (B) of the Paramedian Cross view along with a simulated needle track with the view (C). *The superior articular processes of T4 and T5 vertebrae. SAP, superior articular process; SP, spinous process; TP, transverse process.

Figure 3. Image showing the photograph of needle insertion and sononatomy of the paramedian cross view with needle in situ. PX, paramedian cross view; SP, spinous process; TP, transverse process; USG, ultrasound guidance.