Blunk James A, Nowotny Markus, Scharf Johann, Benrath Justus
Department of Anaesthesiology and Intensive Care Medicine, University Hospital of Cologne, Cologne, Germany.
Pain Med. 2013 Oct;14(10):1593-9. doi: 10.1111/pme.12173. Epub 2013 Jun 11.
Patients presenting with buttock pain syndromes are common. Up to 8% of these conditions may be attributed to piriformis syndrome. Included in several therapeutic and diagnostic approaches, injections directly into the piriformis muscle may be performed. Because the muscle lies very close to neurovascular structures, electromyographic, fluoroscopic, computed tomographic, and magnetic resonance imaging (MRI) guidance have been employed. In few studies, an ultrasound-guided technique was used to inject a local anesthetic into the piriformis muscle without impairing adjacent neuronal structures.
Feasibility study in healthy human subjects. Confirmation of ultrasound-guided injections by MRI.
In 10 male human subjects, ultrasound-guided injections of 3 mL of a local anesthetic into the piriformis muscle were performed.
Directly after the injection, the subjects were placed in an MRI scanner, and the placement of the liquid depot was confirmed by MRI imaging. Somatosensory deficits were evaluated after the injection.
The MRI showed that 9 of 10 of the injections were correctly placed within the piriformis muscle. The distance of the depot to the sciatic nerve decreased over time due to dispersion, but the nerve itself was not reached in the MRI. Only one subject experienced slight, short-term sensorimotor deficits.
MRI confirmed the correct placement of the local anesthetic within the muscle. The dispersion of the fluid 30 minutes after the injection could be visualized. Moreover, only one subject experienced slight motor deficits without anatomical correlate. This ultrasound-guided method will be further employed in ongoing clinical studies.
出现臀部疼痛综合征的患者很常见。这些病症中高达8%可能归因于梨状肌综合征。在多种治疗和诊断方法中，可对梨状肌直接进行注射。由于该肌肉紧邻神经血管结构，因此已采用肌电图、荧光镜检查、计算机断层扫描和磁共振成像（MRI）引导。在少数研究中，使用超声引导技术向梨状肌注射局部麻醉剂而不损伤相邻神经结构。
在健康人体受试者中进行的可行性研究。通过MRI确认超声引导注射。
对10名男性人体受试者进行了超声引导下向梨状肌注射3毫升局部麻醉剂的操作。
注射后立即将受试者置于MRI扫描仪中，通过MRI成像确认液体储库的位置。注射后评估躯体感觉缺陷。
MRI显示10次注射中有9次正确注入梨状肌内。由于扩散，储库与坐骨神经的距离随时间缩短，但MRI未显示神经本身受到影响。只有一名受试者出现轻微的短期感觉运动缺陷。
MRI证实局部麻醉剂在肌肉内的正确位置。注射30分钟后液体的扩散情况可以可视化。此外，只有一名受试者出现轻微运动缺陷，且无解剖学关联。这种超声引导方法将在正在进行的临床研究中进一步应用。
