Faculty Collaboration Database

A prospective, observational study of the relationship between body mass index and depth of the epidural space during lumbar transforaminal epidural steroid injection. Reg Anesth Pain Med 2009;34(2):100-5

Date

03/14/2009

Pubmed ID

19282707

Pubmed Central ID

PMC2715548

DOI

10.1097/AAP.0b013e31819a12ba

Scopus ID

2-s2.0-62949099667 (requires institutional sign-in at Scopus site)   18 Citations

Abstract

BACKGROUND AND OBJECTIVES: Previous studies have concluded that transforaminal epidural steroid injections (ESIs) are more effective than interlaminar injections in the treatment of radiculopathies due to lumbar intervertebral disk herniation. There are no published studies examining the depth of epidural space using a transforaminal approach. We investigated the relationship between body mass index (BMI) and the depth of the epidural space during lumbar transforaminal ESIs.

METHODS: Eighty-six consecutive patients undergoing lumbar transforaminal ESI at the L3-L4, L4-L5, and L5-S1 levels were studied. Using standard protocol, the foraminal epidural space was attained using fluoroscopic guidance. The measured distance from needle tip to skin was recorded (depth to foraminal epidural space). The differences in the needle depth and BMI were analyzed using regression analysis.

RESULTS: Needle depth was positively associated with BMI (regression coefficient [RC], 1.13; P < 0.001). The median depths (in centimeters) to the epidural space were 6.3, 7.5, 8.4, 10.0, 10.4, and 12.2 for underweight, normal, preobese, obese I, obese II, and obese III classifications, respectively. Sex (RC, 1.3; P = 0.02) and race (RC, 0.8; P = 0.04) were also significantly associated with needle depth; however, neither factor remained significant when BMI was accounted as a covariate in the regression model. Age, intervertebral level treated, and oblique angle had no predictive value on foraminal depth (P > 0.2).

CONCLUSION: There is a positive association between BMI and transforaminal epidural depth, but not with age, sex, race, oblique angle, or intervertebral level.

Author List

Brummett CM, Williams BS, Hurley RW, Erdek MA

Author

Robert W. Hurley MD, PhD Adjunct Professor of Anesthesiology and CTSI in the Anesthesiology department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Adolescent
Adult
Aged
Aged, 80 and over
Body Mass Index
Child
Epidural Space
Female
Humans
Injections, Epidural
Low Back Pain
Lumbosacral Region
Male
Middle Aged
Prospective Studies
Steroids
Young Adult