The Effectiveness of Ultrasound Guidance in Caudal Epidural Block

STUDY DESIGN: A prospective study. OBJECTIVES: To evaluate the effectiveness of ultrasound guidance in caudal epidural block and sonographic feature of sacral hiatus. SUMMARY OF LITERATURE REVIEW: High success rate of ultrasound-guided regional nerve block has been reported and recently, ultrasound-guided nerve block in spinal field has been introduced. MATERIALS AND METHODS: Ultrasound-guided caudal epidural block was performed in 48 patients with radiating pain to leg. Patient was placed in the prone position and sonographic image of sacral hiatus was obtained using linear probe. After measuring the intercornual distance, thickness of sacrococcygeal membrane and depth of sacral canal in transverse view, then the probe was rotated 90degrees to obtain the longitudinal view of the sacral hiatus. Under ultrasound guidance, a 21-gauge needle was inserted into the sacral hiatus in parallel with sacrum base. After contrast dye injection, needle placement was checked by the fluoroscopy and then medication was injected into the caudal epidural space. We investigated the change of radiating pain after caudal epidural block using visual analogue scale(VAS). RESULTS: The intercornual distance was mean 16.4+/-2.3mm, thickness of sacrococcygeal membrane was mean 2.8+/-0.9mm and depth of sacral hiatus was mean 2.6+/-0.9mm. There was 97.9% success rate of the caudal epidural block under ultrasound guidance. The mean VAS for radiating pain was improved from 7.5+/-0.7 before the block to 2.8+/-1.5 after the block. CONCLUSIONS: Ultrasound-guided caudal epidural block seems to provide good anatomical landmark of sacral hiatus and an effective tool with high success.

The Validation of Ultrasound-Guided Lumbar Facet Nerve Blocks as Confirmed by Fluoroscopy

STUDY DESIGN: This is a prospective study. PURPOSE: To develop a methodological approach for conducting ultrasound-guided lumbar facet nerve block by defining essential ultrasound-guided landmarks in order to assess the feasibility of this method. OVERVIEW OF LITERATURE: The current role of ultrasound guidance for musculoskeletal intervention treatments has been reported upon in previous literature. METHODS: Ultrasound-guided facet nerve block was done in 95 segments for 50 patients with chronic back pain by facet arthropathy. After the surface landmarks of the spinous process and iliac crest line were confirmed, longitudinal facet views were obtained by a curved array transducer to identify the different spinal segments. The spinous process and facet joint with transverse process were delineated by transverse sonograms at each level and the target point for the block was defined as lying on the upper edge of the transverse process. The needle was inserted toward the target point. After a contrast injection, the placement of the needle and contrast was checked by fluoroscopy. RESULTS: Eighty-seven segments (91.6%) could be guided successfully to the right facet nerve block by using ultrasound. After fluoroscopic control, 8 needles had to be corrected because of problems with other segments (3 cases) and lamina placements (5 cases). For the 42 patients who underwent successful block by ultrasound, however, the mean visual analogue score for back pain was improved from 6.2 +/- 0.9 before the block to 4.0 +/- 1.0 after the block (p = 0.001). CONCLUSIONS: Ultrasound-guided longitudinal facet view and the surface landmarks of the spinous process and iliac crest line seems to be a promising guidance technique for the lumbar facet nerve block technique.