Feasibility of Epidural Localization Using the EpiFaith® Syringe: A Cadaveric Study

Achieving accurate epidural access during surgery is challenging, with failure rates reported as high as 40%. The loss of resistance (LOR) technique remains the standard but relies heavily on the clinician's tactile sense, which can lead to inaccuracies. The EpiFaith® (Flat Medical) syringe, designed with a visual LOR cue, aims to enhance the accuracy of physicians' attempts to achieve epidural access.

This study aimed to evaluate the usability and accuracy of the EpiFaith® syringe for epidural access at the cervical, thoracic, and lumbar levels. The syringe was tested by 2 physicians-one with prior clinical experience using the device and one who would use it for the first time-on cadaver models.

A cadaveric study was conducted by 2 providers who tested the EpiFaith® syringe across multiple spinal levels.

The study was carried out in medical facilities equipped with cadaveric simulation and fluoroscopic imaging.

Five fresh adult cadavers were used, with both providers performing epidural access procedures at spinal levels from C7 to S1. One provider had prior experience using the EpiFaith® syringe, while the other had none. Each procedure used 1 mL of normal saline for LOR detection, and successful epidural access was confirmed using contrast and fluoroscopy. Variables recorded included injection site, number of attempts, first-attempt success rates, device usage, and instances of false LOR.

The experienced provider (Provider 1) performed procedures on 16 spinal levels across 4 cadavers, achieving a 100% first-attempt success rate with no false LOR events. The inexperienced provider (Provider 2) performed procedures on 7 spinal levels, achieving a 57.1% (4/7) first-attempt success rate, with 3 false LOR events (30%). Provider 2 accessed the epidural space successfully after adjusting the technique in response to false LOR signals.

Cadaveric models lack normal physiological conditions, and the small sample size limits generalizability. Further studies in live settings are needed to validate the EpiFaith® syringe's clinical utility and learning curve.

The EpiFaith® syringe is an effective tool for achieving epidural access, particularly for experienced clinicians. Even inexperienced users can adapt to the device's feedback to access the epidural space successfully. Further clinical validation is necessary to confirm the syringe's potential to improve procedural accuracy and reduce false LOR events in real-world settings.