PURPOSE: To determine the incidence of simultaneous vascular and

epidural injection in cervical transforaminal epidural injections.

STUDY DESIGN/SETTING: A prospective observational study at an

academic university-based spine clinic.

PATIENT SAMPLE: Any patient scheduled for a cervical transforaminal

epidural corticosteroid injection by their treating physiatrist or spine sur-

geon was considered a candidate for this study. Patients were excluded

from the study for pregnancy, coagulopathy, systemic infection, allergy

to contrast dye, mental disability, or being unable to give informed

consent. A total of 19 injections were observed.

OUTCOME MEASURES: The presence or absence of an epidural

contrast pattern, vascular contrast pattern, or simultaneous vascular and

epidural contrast pattern was observed under live fluoroscopy and

documented. Fluoroscopy time for each injection was also recorded.

METHODS: Injection of contrast was performed under real-time dynamic

fluoroscopy. The observed uptake pattern was classified into one of three

categories: epidural only, vascular only, or mixed epidural and vascular

when the two occurred simultaneously. The incidence of each pattern

was calculated based on these results.

RESULTS: The incidence of simultaneous epidural and intravascular con-

trast injection was 21%. Another 5% demonstrated intravascular injection

alone, for a total vascular injection incidence of 26%. When present, intra-

vascular injection was more than four times as likely to occur simulta-

neously with epidural injection than it was to be vascular alone.

Compared with the epidural only group, fluoroscopy time was increased

by a mean of 25 seconds in the mixed group, and a mean of 20 seconds

in the vascular only group.

CONCLUSIONS: As with any procedure, safety of epidural injection is

partly related to technique. Other research has shown that aspiration on

the syringe is not a sensitive test to exclude intravascular needle placement.

Due to the transient appearance of vascular contrast patterns, intermittent

fluoroscopy during contrast injection may not demonstrate the vascular

component of simultaneous vascular and epidural injections. Still, it will

show the static epidural contrast image, giving a false impression of epidu-

ral only injection. Serious complications have been reported from acciden-

tal injection of steroids and local anesthetics in the vascular space. In

addition to safety concerns, efficacy may decline with partial injection

outside the desired epidural location. In our opinion, a 21% incidence of

simultaneous epidural and vascular injections is sufficient to warrant live

dynamic fluoroscopy during contrast administration to prevent inadvertent

intravascular injection during cervical transforaminal epidural injections.

FDA DEVICE/DRUG STATUS: This abstract does not discuss or include

any applicable devices or drugs.

CONFLICT OF INTEREST: No conflicts.

doi: 10.1016/j.spinee.2006.06.275

P17. Cervical Disc Chondrocyte Apoptosis and Herniation

Masato Tanaka, MD, Kazuo Nakanishi, Yoshihisa Sugimoto,

Haruhiko Ikuta; Orthopaedic Surgery, Okayama University Medical

School, Japan, Okayama, Japan

BACKGROUND CONTEXT: The cause of degenerative change in the

cartilaginous end plate of human cervical spine remains unclear. Apoptosis

of end plate chondrocytes may play an important role in intervertebral disc

degeneration or herniation, but there is no study about chondrocytes

apoptosis using human cadaver specimen.

PURPOSE: The immunohistochemical study was performed using the

TUNEL (triphosphate-biotin nick end labeling) method to evaluate apopto-

sis in cervical disc cells in the human cadaver specimen. Also the relation

between chondrocyte apoptosis and disc herniation was evaluated.

STUDY DESIGN/SETTING: The apoptosis in human end plate chondro-

cytes was examined using the TUNEL method. The specimens were ob-

tained from human cadavers.

PATIENT SAMPLE: 39 human cervical disc tissues (5 men and 6

women, average 82 years old) were examined to investigate the TUNEL

(þ) end plate chondrocyte using human cadaver specimens.

OUTCOME MEASURES: The specimens were cut on a microtome and

immunostained by TUNEL method. The percentage of cell apoptosis was

calculated in 3 portions: anterior, middle, posterior portion, in each upper

and lower end plate.

METHODS: We evaluated the percentage of chondrocyte apoptosis using

the TUNEL method. The TUNEL method was used to detect the fragmented

DNA known to be associated with apoptotic cell death. The disc tissues were

fixed in 10% neutral formalin and decalcified in 20% EDTA. Tissue samples

then were dehydrated and embedded in paraffin. The specimens were cut on

a microtome and immunostained by TUNEL method. DNA fragmentation

was evaluated by terminal deoxynucleotidyl transferase (TdT)-mediated bi-

otinylated UTP nick end labeling (TUNEL). Detection of apoptotic cells

was performed using the TdT FragEL DNA Fragmentation Detection Kit

(QIA33; Oncogene, Boston, MA, USA) according to manufacturer’s proto-

col. The number of positively stained cells was counted per section and av-

eraged for three sections for each end plate (Fig. 1).

RESULTS: There were 3 disc herniations; 2 were posterior and 1 was an-

terior herniation. Apoptotic cells in end plate chondrocytes were highly ob-

served in the portion of herniated side of the discs. In an anterior herniation

disc specimen, the percentage of cell apoptosis was 15%, 35%, 48%, in

anterior, middle, and posterior portion, respectively. In another anterior

herniation disc specimen, the percentage of cell apoptosis was 16%, 8%,

and 25%, in anterior, middle, and posterior portion, respectively. In a pos-

terior herniation disc specimen, the percentage of cell apoptosis was 28%,

9%, 8%, in anterior, middle, and posterior portion, respectively. There was

no herniation in the other 36 discs, in which apoptosis pattern was divided

into 3 types. Type 1: 6 discs (15.4%); less apoptosis was found in the mid-

dle portion; Type 2: 6 discs (15.4%); less apoptosis was found in upper end

plate; and type 3: 27 discs (69.2%); same percentage of apoptosis.

CONCLUSIONS: Apoptosis of end plate chondrocytes plays an impor-

tant role in intervertebral disc herniation.

FDA DEVICE/DRUG STATUS: This abstract does not discuss or include

any applicable devices or drugs.

CONFLICT OF INTEREST: No conflicts.

doi: 10.1016/j.spinee.2006.06.276

P18. Involvement of Bax-Mediated Apoptosis in Degenerative

Intervertebral Disc

Takuya Fujita, MD, PhD, Yoshihito Yasuda, MD, Hidetaka Hosokawa,

MD, Eiju Hatano, MD, Tetsuhito Okuda, MD, Tadami Matsumoto, MD;

Kanazawa Medical University, Ishikawa, Japan

BACKGROUND CONTEXT: It has been reported that apoptosis of disc

cells occurs in the degenerative intervertebral disc. However, the exact

molecular mechanism of apoptotic disc cell death remains obscure.

PURPOSE: In the present study, the gene expression of Bax (which is an

apoptosis inducer of mitochondrial pathway) and Bcl-2 (an apoptosis

Fig. 1. TUNEL (þ) chondrocytes in human cervical intervertebral disc

end plate.

91SProceedings of the NASS 21st Annual Meetings / The Spine Journal 6 (2006) 1S–161S