Clinical characteristics of the study participants
| LAT group (n=38) | CLO group (n=41) | P value | |
| Age (years) | 64.0 (56.0–72.0) | 63.0 (58.0–70.0) | 0.768 |
| Sex, male (%) | 22 (57.9) | 30 (73.2) | 0.233 |
| Body mass index (kg/m2) | 23.4±3.2 | 23.5±2.9 | 0.816 |
| Cause of interventions | 0.473 | ||
| Spontaneous intracranial hypotension | 2 (5.3) | 0 (0.0) | |
| Herpes zoster and postherpetic neuralgia | 7 (18.4) | 9 (22.0) | |
| Cancer pain | 0 (0.0) | 2 (4.9) | |
| Chronic postsurgical pain | 2 (5.3) | 2 (4.9) | |
| Acute postoperative pain* | 25 (65.8) | 27 (65.9) | |
| Others† | 2 (5.3) | 1 (2.3) | |
| Type of intervention | 0.329 | ||
| Epidural steroid injection | 11 (28.9) | 13 (31.7) | |
| Blood patch | 2 (9.5) | 0 (0.0) | |
| Epidural catheter placement | 25 (65.8) | 28 (68.3) | |
| Target level | 0.600 | ||
| T4−T5 | 4 (10.5) | 7 (17.1) | |
| T5−T6 | 3 (7.9) | 4 (9.8) | |
| T6−T7 | 12 (31.6) | 8 (19.5) | |
| T7−T8 | 19 (50.0) | 22 (53.7) | |
| Location of needle insertion, right (%) | 20 (52.6) | 28 (68.3) | 0.233 |
Data are expressed as means (SD), numbers (%), or medians (IQR). LAT and CLO groups comprised patients who underwent mid-thoracic epidural access under the fluoroscopic lateral view and contralateral oblique view, respectively.
*Acute postoperative pain corresponded to the acute pain after thoracic and upper abdominal surgeries.
†Others included thoracic herniated intervertebral disc and thoracic spinal stenosis.
CLO, contralateral oblique; LAT, lateral.