This retrospective study used abdominal computed tomography (CT) scan images to determine the optimal safe oblique angle for fluoroscopy in fluoroscopeassisted coeliac plexus block (CPB). Abdominal CT scans from 131 patients were included in the study: 42 patients with cancer of the pancreas head, 45 with cancer of the pancreas body and tail and 44 with chronic pancreatitis. The oblique angle and entry distance from the midline were measured at the T12 and L1 levels, and the safe angle range that avoided puncture of the organs was also measured. The optimal angle varied between the T12 and L1 levels, and between the right and left sides at the T12 level. There was no difference in the oblique angle between the patient groups. The optimal oblique angle for fluoroscopy was determined to be 17° for right T12, 18° for left T12, and 19° for both left and right L1.

SummaryWe investigated the forces required to remove thoracic epidural catheters to determine the effect of patient position on removal. Eighty-four patients undergoing open thoracotomy and thoracic patient-controlled epidural analgesia were enrolled. Catheterisation was performed under fluoroscopic guidance before surgery, and the patients were allocated to one of three position groups for removal: prone; sitting; and lateral. On the third postoperative day, the peak tension during withdrawal in the assigned position was measured. No differences in mean (SD) forces were found between groups: prone 1.61 (0.39) N, Thoracic epidural catheters are usually removed without complications. Although shearing or breakage of an epidural catheter during removal is a rare occurrence, it may require surgical extraction [1,2]. Shearing or breakage of an epidural catheter may result from unintended trauma during insertion or removal [3,4]. Some papers have evaluated the factors (position, sex, age, height, length of catheter under skin, etc.) possibly affecting the necessary withdrawal force for lumbar epidural catheters and spinal catheters [4][5][6][7][8]. However, there are no studies regarding factors affecting the withdrawal forces required for thoracic epidural catheters. Differences in anatomy and techniques used to identify the epidural space mean data cannot automatically be extrapolated from lumbar to thoracic epidural catheters. In particular, the position of patients could plausibly influence catheter removal as in lumbar epidural epidural catheters [5,6]. Therefore, we investigated the effects of patient position (prone, sitting or lateral flexed) on the withdrawal forces necessary to remove thoracic epidural catheters. We also evaluated the influence of other factors such as sex, age, height, body mass index (BMI), the depth from the skin to the epidural space, the angle made by the skin and the Tuohy needle and the length of the catheter in the epidural space on withdrawal forces. MethodsThis prospective randomised study was approved by the Institutional Review Board of our institute and written informed consent was obtained from all participants.Eighty-four patients, aged 25-75 years, undergoing elective open thoracotomy and thoracic patient-controlled epidural analgesia (PCEA) for postoperative pain control were consecutively enrolled in this study. Exclusion criteria included: an allergy to contrast media; general contraindications to thoracic epidural catheterisation (blood clotting disorders, infection at the proposed insertion site, patient