1. Introduction

Epidural steroid injections are known to be the most effective method for the treatment of the back pain and radicular pain caused by herniated disks or spinal stenosis. The injection methods can be divided into the dorsal epidural approach such as interlamina and ventral epidural approach such as transforaminal injection. In general, it is known that drug injection into the ventral epidural space is more effective. This is possible in thoracic and lumbar region, but it is so dangerous in cervical region for vertebral artery. This author has tried the transforaminal epdidural approach in upper thoracic region as an alternative methods for injecting drugs into cervical ventral space in patient with unsatisfactory to interlamina cervical epidural injection or cervical transforaminal epidural injection. This study is to evaluate the effectiveness of thoracic approach by analysing the outpatient progress note and PACS data.

2. Materials and methods

Patients

By using PACS data, I selected 130 patients who visited our clinic from May 1, 2018 to March 31, 2019. Among them, patients diagnosed with herpes zoster, post-herpetic neuralgia were excluded, and in case of multiple injections in the same patient, only the first case was included. If the image quality is not good to determine the success of the injection, excluded the case.(In the first 3 months, I used analogue type, 6 inch fluoroscope)

Estimation

Estimation for Block quality

1 ml of contrast agent(Omnipaque 300, GE healthcare korea) per intervertebral foramen was injected and after that I classified the quality by 5 categories(Excellent, Good, Moderate, Poor) base on the fluoroscopic image.

  • Criterias for Block Quality Estimation
    • Excellent: More than 90% of contrast agent was injected into epidural space or multilevel spread
    • Good: More than 50% of contrast agent was injected into epidural space
    • Moderate: It was injected into epidural space but almost contrast was injected into surrounding tissue
    • Poor: It was not injected into epidural space
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Block Quality Classification

Block Quality Classification

Estimation for clinical responses

After contrast injection, Diluted 2% mepivacaine with NSS 20ml(0.1% mepivacaine) and hyaluronidase 1500IU was injected. I checked the clinical response on the next visit(after 3days ~ 7days), and classified the responses by 5 catergories(Excellent, Good, Moderate, No change, Aggravated).

  • Criteria for Clinical Response Estimation
    • Excellent: Pain improved more than 80% than before injection and there was no inconvenience in daily life
    • Good: Pain improved more than 50% than before injection and there was minor inconvenience in daily life
    • Moderate: Pain improved than before injection but there were disabilities in daily life
    • No Change: There was no change than before injection
    • Aggravated: Pain aggravated or other type of pain occurred than before injection

Data analysis

I chose the linear-by-linear test for the association of block quality and clinical response. Statistical program was R.

3. Results

Patients chracteristics

Table 1. Demographics

Variables
Sex
Male 33
Female 46
Age
Median 59
Range 37 - 81

Table 2. Pain referring area

Pain area Frequency(%)
Upper arm 28(35.4)
Lower arm 23(29.1)
Neck 21(26.6)
Shouder 20(25.3)
Scapular 19(24.1)
Hand 15(19.0)
Inerscapular 7(8.9)
Headache 5(5.3)
Trapezius 5(5.3)

Table 3. Pain characteristics

Pain characteristics Frequency(%)
Aching 59(74.7)
Paraesthesia 25(31.6)
Tightness 9(11.4)
Tingling 7(8.9)
Cramps 3(3.8)
Decreased sense 2(2.5)
Coldness 1(1.3)
Pinrpicking 1(1.3)
Weakness 1(1.3)

Total 79 patients were included in this study. Descriptive statistics expressed in graphical way. The p-value of asymptotic Linear-by-Linear association test was 0.0006, so there is a statitically significant association between block quality and clinical response.

Graphical summary

Distribution of Sex and Age

Distribution of Sex and Age

Pain referring area and character

Pain referring area and character

Balloon plotting for association

Balloon plotting for association

Linear-by-linear test for assocaition

lbl_test(tab1)
## 
##  Asymptotic Linear-by-Linear Association Test
## 
## data:  Var2 (ordered) by
##   Var1 (Poor < Moderate < Good < Excellent)
## Z = -3.41, p-value = 0.0006496
## alternative hypothesis: two.sided

4. Conclusion

It can be effective with T1/2 ro T2/3 transforaminal epidural approach for the cervical ventral epidural injection.