الفهرس 
BASICS OF ULTRASOUNDOnly 14 pages are availabe for public view
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Abstract
Ultrasound is a valuable tool for imaging critical soft tissue structures relevant to the sympathetic chain; guiding needle advancement, and confirming the spread of injectate in the proper fascial plane, without exposing healthcare providers and patients to the risks of radiation.
There are only a few reports and observational studies that have demonstrated the advantages of ultrasound-guided stellate ganglion block over the traditional fluoroscopy-guided technique. However, despite a lack of scientific evidence in the past, pain practitioners followed a common-sense and sound-judgment approach when they transitioned from the blind approach to the now-routine fluoroscopic-guided approach for performing stellate ganglion block (SGB). And with the introduction of ultrasound guidance in pain management, many pain practitioners are following the same path.
Ultrasound-guided stellate ganglion block, with direct visualization of the multiple vulnerable soft tissue structures compacted in a tight vascular space around the sympathetic chain, appears to be safer and more effective than traditional approaches. While future clinical studies will undoubtedly further establish ultrasound-guided SGB as the superior approach, the concept is already very appealing today, to the point that RCTs comparing ultrasound-guided SGB to the blind approach, or even to the fluoroscopy guided technique, may not be necessary in the future.
That will be useful in treatment of pain syndromes as complex regional pain syndromes type I (reflex sympathetic dystrophy) and type II (causalgia), hyperhidrosis, refractory angina, phantom limb pain, herpes zoster, and pain of the head and neck. Also, it is of value in arterial vascular insufficiency which include Raynaud syndrome, scleroderma, obliterative vascular diseases, vasospasm, trauma, and emboli. No benefit is seen in patients with venous insufficiency.
Recent advances in US technology and image processing capabilities of US machines have made it possible to image the Thoracic Paravertebral Space(TPVS). Being able to delineate the relevant anatomy of the TPVS before and during a TPVB in real-time may offer several advantages. Ultrasound is noninvasive, safe, simple to use, with no radiation, and it appears to be a promising alternative to traditional landmark-based techniques for thoracic paravertebral block (TPVB). Using US, one is able to preview the paravertebral anatomy before block placement and determine the depth to the transverse process and pleura. The latter defines the maximum safe depth for needle insertion and may help reduce the incidence of pleural puncture. Ultrasound guidance during TPVB also allows the block needle to be advanced accurately to the TPVS and visualize the distribution of the local anesthetic during the injection in real-time. This may translate into improved technical outcomes, higher success rates, and reduced needle-related complications. It is also an excellent teaching tool for demonstrating the anatomy of the TPVS and has the potential to improve the learning curve of this technique.
Endoscopic ultrasound (EUS)-guided celiac plexus block is a promising new method for controlling the abdominal pain associated with chronic pancreatitis. The EUS-guided celiac plexus block technique provided more substantial pain relief and a greater duration of pain relief than the CT technique. Furthermore, the EUS technique was the preferred procedure among the majority of study subjects who had experienced both techniques. This was attributed to a more liberal use of conscious sedation and the lack of back pain usually associated with the transposterior CT approach.
Indications for celiac plexus block are several. Celiac plexus block with local anesthetic is indicated as a diagnostic tool to determine whether flank, retroperitoneal, or upper abdominal pain is sympathetically mediated via the celiac plexus. Daily celiac plexus blocks with local anesthetic are also useful in the palliation of pain secondary to acute pancreatitis. Celiac plexus block is also used successfully to palliate the acute pain of arterial embolization of the liver for cancer therapy and to reduce the pain of abdominal “angina” associated with visceral arterial insufficiency.
Neurolytic celiac plexus block used to treat pain secondary to malignancies of the retroperitoneum and upper abdomen. It is also useful in some chronic benign abdominal pain syndromes.
Ultrasound can be successively used to locate thesacrococcygeal joint and facilitate the performance of ganglion impar block. However, ultrasound does not replace fluoroscopy, because lateral fluoroscopy is still required to establish safe depth, and monitor the spread of the injectate.
Ganglion impar block can be useful in the evaluation and management of sympathetically mediated pain of the perineum, rectum, and genitalia. Visceral pain or sympathetically maintained pain in the perineal area associated with the malignancies of the pelvis may be effectively treated with neurolysis of the ganglion impar.