A Comparison Study Between Contrast Spread and Loss of Resistance Techniques

Identification of Epidural Space: A Comparison Study Between Contrast Spread and Loss of Resistance Techniques

Early epidural space identification is critical to the efficacy and safety of cervical epidural steroid injections (CESI) [1]. Currently, the accepted method for epidural space recognition is the loss of resistance technique (LORT). I perform CESIs with fluoroscopy only [2]. I hypothesized that the contrast spread technique (CST) might recognize epidural space concurrently with or sooner than LORT. I also suggested that smaller needles might be employed with CST but not with LORT. To test my hypotheses, I conducted a comparison study.

The study participants were patients of Astoria Pain Management, New York, USA (age 28-72 years) with a clinical diagnosis of cervical radiculitis. The Canadian SHIELD Ethics Review Board approved this study (July 18, 2019. REB tracking number: 19-06-002), conducted from August 19, 2019, to October 8, 2019. There was no funding for this study. Patients were eligible for the study if they met the criteria for cervical ESI, which included clinical and recent MRI findings confirming the diagnosis of cervical radiculitis and inadequate pain relief with conservative care for more than 3 months. Other criteria were if the procedure was covered by medical insurance, and if they signed informed consent. Patients were excluded from the study if they were taking anticoagulants or had serious comorbidities such as congestive heart failure. The patients were divided into two groups of 20 each and underwent CESI with either an 18G or a 25G Tuohy needle. The skin was anesthetized with 1% lidocaine in the 18G group but not in the 25G group. All cervical epidurals were performed utilizing the fluoroscopy only method when the needle was navigated from the skin toward the epidural space under contralateral oblique fluoroscopy [3], and the contrast spread technique [4,5] was employed for epidural space identification. After radiological confirmation of the epidural spread, LOR was tested using an Epidrum® device (Exmoor Innovations Ltd., Somerset, UK). I utilized the Epidrum device as I consider it a more objective and reproducible method for epidural space identification independent of the provider's skill with the LORT, and because its success rate is comparable to the results attained by trained anesthesiologists employing the LOR syringe [6, 7, 8]. Subsequently, accompanied by the radiology assistant, I observed the Epidrum for 30 seconds or more; if the Epidrum deflated, the result was positive. However, if the device remained inflated, the result was reported as negative. The collected data was then analyzed.

Fluoroscopy only, cervical epidural steroid injection, contrast spread technique, loss of resistance technique, epidural space identification

The patients were divided into two groups of 20 each and underwent CESI with either an 18G or a 25G Tuohy needle.

In the 18G group, all CESIs were performed utilizing the fluoroscopy only method when the needle was navigated from the skin toward the epidural space under contralateral oblique fluoroscopy, and the contrast spread technique was employed for epidural space identification. After radiological confirmation of the epidural spread, LOR was tested using an Epidrum® device (Exmoor Innovations Ltd., Somerset, UK).

In the 25G group, all CESIs were performed utilizing the fluoroscopy only method when the needle was navigated from the skin toward the epidural space under contralateral oblique fluoroscopy, and the contrast spread technique was employed for epidural space identification. After radiological confirmation of the epidural spread, LOR was tested using an Epidrum® device (Exmoor Innovations Ltd., Somerset, UK).

Cervical epidural procedure and epidural space recognition were performed utilizing the fluoroscopy only method. With this technique, needle navigation from the skin toward the epidural space is performed under contralateral oblique fluoroscopy. With the needle at the ventral interlaminar line, the contrast spread technique was employed for epidural space identification. After radiological confirmation of the epidural spread, LOR was tested using an Epidrum® device (Exmoor Innovations Ltd., Somerset, UK). Subsequently, accompanied by the radiology assistant, I observed the Epidrum for 30 seconds or more; if the Epidrum deflated, thus confirming LOR, the result was positive. However, if the device remained inflated, the result was reported as negative. The collected data was then analyzed.

Cervical epidural procedure and epidural space recognition were performed utilizing the fluoroscopy only method. With this technique, needle navigation from the skin toward the epidural space is performed under contralateral oblique fluoroscopy. With the needle at the ventral interlaminar line, the contrast spread technique was employed for epidural space identification. After radiological confirmation of the epidural spread, LOR was tested using an Epidrum® device (Exmoor Innovations Ltd., Somerset, UK). Subsequently, accompanied by the radiology assistant, I observed the Epidrum for 30 seconds or more; if the Epidrum deflated, thus confirming LOR, the result was positive. However, if the device remained inflated, the result was reported as negative.

Cervical epidural procedure and epidural space recognition were performed utilizing the fluoroscopy only method. With this technique, needle navigation from the skin toward the epidural space is performed under contralateral oblique fluoroscopy. With the needle at the ventral interlaminar line, the contrast spread technique was employed for epidural space identification. After radiological confirmation of the epidural spread, LOR was tested using an Epidrum® device (Exmoor Innovations Ltd., Somerset, UK). Subsequently, accompanied by the radiology assistant, I observed the Epidrum for 30 seconds or more; if the Epidrum deflated, thus confirming LOR, the result was positive. However, if the device remained inflated, the result was reported as negative.

Inclusion Criteria: Clinical and recent MRI findings confirming the diagnosis of cervical radiculitis Inadequate pain relief with conservative care for more than 3 months Signed informed consent The procedure was covered by medical insurance Exclusion Criteria: Bleeding disorder or anticoagulants therapy Serious comorbidities such as congestive heart failure Pregnancy Uncontrolled diabetes mellitus Refusal to participate in the study

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