The authors have no acknowledgements.

The protocol illustrated here follows the guidelines of the human research ethics committee at Brigham and Women&#39;s Hospital.
1. Preoperative Protocol
<ol>
	<li>Assess patients with spinal pathology in clinic and determine eligibility for spinal surgery. Perform neurological assessment and obtain CT or MRI scan to identify spinal lesion.</li>
	<li>Include patients who have an intradural pathology such as schwannoma, ependymoma, meningioma, astrocytoma, etc.; or patients who have ...

<ol>
	<li>Reid, M. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ultrasonic+visualization+of+a+cervical+cord+cystic+astrocytoma.">Ultrasonic visualization of a cervical cord cystic astrocytoma.</a> AJR. American Journal of Roentgenology. 131 (5), 907-908 (1978).</li><li>Dohrmann, G. J., Rubin, J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intraoperative+ultrasound+imaging+of+the+spinal+cord:+syringomyelia,+cysts,+and+tumors--a+preliminary+report.">Intraoperative ultrasound imaging of the spinal cord: syringomyelia, cysts, and tumors--a preliminary report.</a> Surgical Neurology. 18 (6), 395-399 (1982).</li><li>Rubin, J. M., Dohrmann, G. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Use+of+ultrasonically+guided+probes+and+catheters+in+neurosurgery.">Use of ultrasonically guided probes and catheters in neurosurgery.</a> Surgical Neurology. 18 (2), 143-148 (1982).</li><li>Braun, I. F., Raghavendra, B. N., Kricheff, I. I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Spinal+cord+imaging+using+real-time+high-resolution+ultrasound.">Spinal cord imaging using real-time high-resolution ultrasound.</a> Radiology. 147 (2), 459-465 (1983).</li><li>Hutchins, W. W., Vogelzang, R. L., Neiman, H. L., Fuld, I. L., Kowal, L. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Differentiation+of+tumor+from+syringohydromyelia:+intraoperative+neurosonography+of+the+spinal+cord.">Differentiation of tumor from syringohydromyelia: intraoperative neurosonography of the spinal cord.</a> Radiology. 151 (1), 171-174 (1984).</li><li>Juthani, R. G., Bilsky, M. H., Vogelbaum, M. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Current+Management+and+Treatment+Modalities+for+Intramedullary+Spinal+Cord+Tumors.">Current Management and Treatment Modalities for Intramedullary Spinal Cord Tumors.</a> Current Treatment Options in Oncology. 16 (8), 39 (2015).</li><li>Knake, J. E., Gabrielsen, T. O., Chandler, W. F., Latack, J. T., Gebarski, S. S., Yang, P. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Real-time+sonography+during+spinal+surgery.">Real-time sonography during spinal surgery.</a> Radiology. 151 (2), 461-465 (1984).</li><li>Montalvo, B. M., Quencer, R. M., Green, B. A., Eismont, F. J., Brown, M. J., Brost, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intraoperative+sonography+in+spinal+trauma.">Intraoperative sonography in spinal trauma.</a> Radiology. 153 (1), 125-134 (1984).</li><li>Montalvo, B. M., Quencer, R. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intraoperative+sonography+in+spinal+surgery:+current+state+of+the+art.">Intraoperative sonography in spinal surgery: current state of the art.</a> Neuroradiology. 28 (5-6), 551-590 (1986).</li><li>Pasto, M. E., Rifkin, M. D., Rubenstein, J. B., Northrup, B. E., Cotler, J. M., Goldberg, B. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Real-time+ultrasonography+of+the+spinal+cord:+intraoperative+and+postoperative+imaging.">Real-time ultrasonography of the spinal cord: intraoperative and postoperative imaging.</a> Neuroradiology. 26 (3), 183-187 (1984).</li><li>Mari, A. R., Shah, I., Imran, M., Ashraf, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Role+of+intraoperative+ultrasound+in+achieving+complete+resection+of+intra-axial+solid+brain+tumours.">Role of intraoperative ultrasound in achieving complete resection of intra-axial solid brain tumours.</a> JPMA. The Journal of the Pakistan Medical Association. 64 (12), 1343-1347 (2014).</li><li>Ivanov, M., Budu, A., Sims-Williams, H., Poeata, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Using+Intraoperative+Ultrasonography+for+Spinal+Cord+Tumor+Surgery.">Using Intraoperative Ultrasonography for Spinal Cord Tumor Surgery.</a> World Neurosurgery. 97, 104-111 (2017).</li><li>Blumenkopf, B., Daniels, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intraoperative+ultrasonography+(IOUS)+in+thoracolumbar+fractures.">Intraoperative ultrasonography (IOUS) in thoracolumbar fractures.</a> Journal of Spinal Disorders. 1 (1), 86-93 (1988).</li><li>McGahan, J. P., Benson, D., Chehrazi, B., Walter, J. P., Wagner, F. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intraoperative+sonographic+monitoring+of+reduction+of+thoracolumbar+burst+fractures.">Intraoperative sonographic monitoring of reduction of thoracolumbar burst fractures.</a> AJR. American Journal of roentgenology. 145 (6), 1229-1232 (1985).</li><li>Quencer, R. M., Montalvo, B. M., Eismont, F. J., Green, B. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intraoperative+spinal+sonography+in+thoracic+and+lumbar+fractures:+evaluation+of+Harrington+rod+instrumentation.">Intraoperative spinal sonography in thoracic and lumbar fractures: evaluation of Harrington rod instrumentation.</a> AJR. American Journal of roentgenology. 145 (2), 343-349 (1985).</li><li>Sosna, J., Barth, M. M., Kruskal, J. B., Kane, R. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intraoperative+sonography+for+neurosurgery.">Intraoperative sonography for neurosurgery.</a> Journal of Ultrasound in Medicine: Official Journal of the American Institute of Ultrasound in Medicine. 24 (12), 1671-1682 (2005).</li><li>Raymond, C. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Brain,+spine+surgeons+say+yes+to+ultrasound.">Brain, spine surgeons say yes to ultrasound.</a> JAMA. 255 (17), 2258-2262 (1986).</li><li>Toktas, Z. O., Sahin, S., Koban, O., Sorar, M., Konya, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Is+intraoperative+ultrasound+required+in+cervical+spinal+tumors?+A+prospective+study.">Is intraoperative ultrasound required in cervical spinal tumors? A prospective study.</a> Turkish Neurosurgery. 23 (5), 600-606 (2013).</li><li>. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Surgical Approaches to the Spine. , (2015).</li><li>Friedman, J. A., Wetjen, N. M., Atkinson, J. L. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Utility+of+intraoperative+ultrasound+for+tumors+of+the+cauda+equina.">Utility of intraoperative ultrasound for tumors of the cauda equina.</a> Spine. 28 (3), 288-290 (2003).</li><li>Zhou, H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intraoperative+ultrasound+assistance+in+treatment+of+intradural+spinal+tumours.">Intraoperative ultrasound assistance in treatment of intradural spinal tumours.</a> Clinical Neurology and Neurosurgery. 113 (7), 531-537 (2011).</li><li>Harrop, J. S., Ganju, A., Groff, M., Bilsky, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Primary+intramedullary+tumors+of+the+spinal+cord.">Primary intramedullary tumors of the spinal cord.</a> Spine. 34, 69-77 (2009).</li><li>Quencer, R. M., Montalvo, B. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Normal+intraoperative+spinal+sonography.">Normal intraoperative spinal sonography.</a> AJR. American journal of roentgenology. 143 (6), 1301-1305 (1984).</li><li>Aoyama, T., Hida, K., Akino, M., Yano, S., Iwasaki, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Detection+of+residual+disc+hernia+material+and+confirmation+of+nerve+root+decompression+at+lumbar+disc+herniation+surgery+by+intraoperative+ultrasound.">Detection of residual disc hernia material and confirmation of nerve root decompression at lumbar disc herniation surgery by intraoperative ultrasound.</a> Ultrasound in Medicine &amp; Biology. 35 (6), 920-927 (2009).</li><li>Bose, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Thoracic+extruded+disc+mimicking+spinal+cord+tumor.">Thoracic extruded disc mimicking spinal cord tumor.</a> The Spine Journal: Official Journal of the North American Spine Society. 3 (1), 82-86 (2003).</li><li>Harel, R., Knoller, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intraoperative+spine+ultrasound:+application+and+benefits.">Intraoperative spine ultrasound: application and benefits.</a> European Spine Journal: Official Publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society. 25 (3), 865-869 (2016).</li><li>Lazennec, J. Y., Saillant, G., Hansen, S., Ramare, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intraoperative+ultrasonography+evaluation+of+posterior+vertebral+wall+displacement+in+thoracolumbar+fractures.">Intraoperative ultrasonography evaluation of posterior vertebral wall displacement in thoracolumbar fractures.</a> Neurologia Medico-Chirurgica. 39 (1), 8-15 (1999).</li><li>Matsuyama, Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cervical+myelopathy+due+to+OPLL:+clinical+evaluation+by+MRI+and+intraoperative+spinal+sonography.">Cervical myelopathy due to OPLL: clinical evaluation by MRI and intraoperative spinal sonography.</a> Journal of Spinal Disorders &amp; Techniques. 17 (5), 401-404 (2004).</li><li>Mueller, L. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ultrasound-guided+spinal+fracture+repositioning,+ligamentotaxis,+and+remodeling+after+thoracolumbar+burst+fractures.">Ultrasound-guided spinal fracture repositioning, ligamentotaxis, and remodeling after thoracolumbar burst fractures.</a> Spine. 31 (20), 739-747 (2006).</li><li>Nishimura, Y., Thani, N. B., Tochigi, S., Ahn, H., Ginsberg, H. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Thoracic+discectomy+by+posterior+pedicle-sparing,+transfacet+approach+with+real-time+intraoperative+ultrasonography:+Clinical+article.">Thoracic discectomy by posterior pedicle-sparing, transfacet approach with real-time intraoperative ultrasonography: Clinical article.</a> Journal of Neurosurgery. Spine. 21 (4), 568-576 (2014).</li><li>Randel, S., Gooding, G. A., Dillon, W. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sonography+of+intraoperative+spinal+arteriovenous+malformations.">Sonography of intraoperative spinal arteriovenous malformations.</a> Journal of Ultrasound in Medicine: Official Journal of the American Institute of Ultrasound in Medicine. 6 (9), 539-544 (1987).</li><li>Seichi, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intraoperative+ultrasonographic+evaluation+of+posterior+decompression+via.+laminoplasty+in+patients+with+cervical+ossification+of+the+posterior+longitudinal+ligament:+correlation+with+2-year+follow-up+results.">Intraoperative ultrasonographic evaluation of posterior decompression via. laminoplasty in patients with cervical ossification of the posterior longitudinal ligament: correlation with 2-year follow-up results.</a> Journal of Neurosurgery. Spine. 13 (1), 47-51 (2010).</li><li>Tian, W., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intraoperative+3-dimensional+navigation+and+ultrasonography+during+posterior+decompression+with+instrumented+fusion+for+ossification+of+the+posterior+longitudinal+ligament+in+the+thoracic+spine.">Intraoperative 3-dimensional navigation and ultrasonography during posterior decompression with instrumented fusion for ossification of the posterior longitudinal ligament in the thoracic spine.</a> Journal of Spinal Disorders &amp; Techniques. 26 (6), 227-234 (2013).</li><li>Tokuhashi, Y., Matsuzaki, H., Oda, H., Uei, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effectiveness+of+posterior+decompression+for+patients+with+ossification+of+the+posterior+longitudinal+ligament+in+the+thoracic+spine:+usefulness+of+the+ossification-kyphosis+angle+on+MRI.">Effectiveness of posterior decompression for patients with ossification of the posterior longitudinal ligament in the thoracic spine: usefulness of the ossification-kyphosis angle on MRI.</a> Spine. 31 (1), 26-30 (2006).</li><li>Vasudeva, V. S., Abd-El-Barr, M., Pompeu, Y. A., Karhade, A., Groff, M. W., Lu, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Use+of+Intraoperative+Ultrasound+During+Spinal+Surgery.">Use of Intraoperative Ultrasound During Spinal Surgery.</a> Global Spine Journal. 7 (7), 648-656 (2017).</li><li>Alaqeel, A., Abou Al-Shaar, H., Alaqeel, A., Al-Habib, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+utility+of+ultrasound+for+surgical+spinal+decompression.">The utility of ultrasound for surgical spinal decompression.</a> Medical Ultrasonography. 17 (2), 211-218 (2015).</li><li>Della Pepa, G. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Real-time+intraoperative+contrast-enhanced+ultrasound+(CEUS)+in+vascularized+spinal+tumors:+a+technical+note.">Real-time intraoperative contrast-enhanced ultrasound (CEUS) in vascularized spinal tumors: a technical note.</a> Acta Neurochirurgica. 160 (6), 1259-1263 (2018).</li><li>Della Pepa, G. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Integration+of+Real-Time+Intraoperative+Contrast-Enhanced+Ultrasound+and+Color+Doppler+Ultrasound+in+the+Surgical+Treatment+of+Spinal+Cord+Dural+Arteriovenous+Fistulas.">Integration of Real-Time Intraoperative Contrast-Enhanced Ultrasound and Color Doppler Ultrasound in the Surgical Treatment of Spinal Cord Dural Arteriovenous Fistulas.</a> World Neurosurgery. 112, 138-142 (2018).</li></ol>

The authors have nothing to disclose.

Intraoperative ultrasound in the spinal surgery has largely fallen out of favor with the advent of newer technology, however, it continues to provide several advantages over the other available imaging modalities such as MRI and CT6,9,16,17,18. In addition to being inexpensive, in this protocol we also show that it is simple to use and can provide visualizatio...

Ultrasound is one of the most common diagnostic tools in medicine, particularly for visualizing pathology in the abdomen, limbs, and neck. However, its use to investigate cranial and spinal lesions is not currently widely utilized. In 1978, Reid was the first to report the use of ultrasound to visualize cervical cord cystic astrocytoma1. Here, scans were performed with the patient&#39;s neck flexed to allow opening of the intralaminar window. Four years later, in 1982, Dohrmann and Rubin reported the use of ultrasound intraoperatively to visualize the intradural space in 10 patients2. Pathologies identified with intraoperative ultrasound among the 10 patients included syringomyelia, spinal cord cysts, and intramedullary and extramedullary tumors. They further demonstrated the use of intraoperative ultrasound to guide catheters and probes for biopsy of tumors, drainage of cysts, and ventricular shunt catheter placement3. This allowed the real-time monitoring and precise positioning of probes/catheters, reducing inaccuracy and errors in placement. Following these initial reports, several others have published the use of intraoperative ultrasound for guiding spinal cord cyst drainage, intramedullary and extramedullary tumor resection, and syringo-subarachnoid shunt catheter placement4,5,6,7,8,9,10. Additionally, it has been shown to also increase rate of complete resection of intra-axial solid brain tumors and spinal intradural tumors11,12. Intraoperative ultrasound has also proven to be useful for the intraoperative surgical planning before manipulation of the tissue and subsequent visualization of adequate neural element decompression in patients with spine fractures7,9,13,14,15.
With the advent of newer intraoperative technology allowing clearer visualization of soft tissues, such as magnetic resonance imaging (MRI) and computed tomography (CT), intraoperative ultrasound has become less common and a less favored intraoperative imaging modality among neurosurgeons today16. However, intraoperative ultrasound can have advantages over these newer technologies in certain operative cases (Table 1). Intraoperative ultrasound has shown to demonstrate better soft tissue visualization of intradural structures when compared with intraoperative CT (iCT) or cone-beam CT (cbCT)9,17. While intraoperative MRI (iMRI) is useful where available because of the higher soft tissue resolution it provides, it is costly, time consuming and does not provide real-time images6, 16,18. An example is in the circumstance of an intradural mass ventral to the thecal sac that the surgeon is unable to directly visualize. Additionally, despite being operator dependent, from our experience, intraoperative ultrasound is fairly simple to use and can be easily read without a radiologist.

<table border="0" cellpadding="0" cellspacing="0" style="width:848px;" width="847">
	<tbody>
		<tr height="40">
			<td height="40" style="height:40px;width:215px;">Aloka Prosound 5 mobile ultrasound machine</td>
			<td style="width:123px;">Hitachi</td>
			<td style="width:344px;">N/A</td>
			<td style="width:167px;">any comparable devices on the market should suffice</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">UST-9120 transducer probe.</td>
			<td>Hitachi</td>
			<td>UST-9120</td>
			<td>Has a 20mm diameter with 10 to 4.4 MHz frequency range (any comparable compatible transducer should suffice).</td>
		</tr>
	</tbody>
</table>

intraoperative ultrasound in spinal surgery

Since the 1980s, there have been several reports for the use of intraoperative ultrasound as a useful adjunct in spinal surgery. However, with the advent of newer cutting-edge imaging modalities, the use of intraoperative ultrasound in spine surgery has largely fallen out of favor. Despite this, intraoperative ultrasound continues to provide several advantages over other intraoperative techniques such as magnetic resonance imaging and computed tomography including being more cost-effective, efficient, and easy to operate and interpret. Additionally, it remains the only method for the real-time visualization of soft tissue and pathologies. This paper focuses on the advantages of using intraoperative ultrasound, especially in cases of intradural lesions and lesions ventral to the thecal sac when approaching posteriorly.

On normal spine ultrasound imaging, the dura is an echogenic layer that surrounds the anechoic spinal fluid. The spinal cord is distinguished by its homogenous appearance and low echogenicity which is surrounded by an echogenic rim. This echogenic rim is due to the density shift from the spinal fluid to the spinal cord. The central canal appears as a bright central echo, while exiting nerve roots appear highly echogenic, particularly at the cauda equina16. Intraope...

Watch this Scientific Journal Video about Intraoperative Ultrasound in Spinal Surgery at JoVE.com

Intraoperative Ultrasound in Spinal Surgery

Here, we present a protocol on the use of intraoperative ultrasound in spinal surgery, particularly in cases of intradural lesions and lesions in the ventral spinal canal when using a posterior approach.

Since the 1980s, there have been several reports for the use of intraoperative ultrasound as a useful adjunct in spinal surgery. However, with the advent ...

Intraoperative ultrasound for spine surgery is very useful for intradural pathology or ventral spinal cord pathology that allow the surgeon to visualize the lesion before opening dura. This also help the surgeon to locate where the lesion is and also to confirm the adequate decompression of the spinal cord after the lesion removal, tumor removal. It provides the real time information that's very, very useful for the spine surgeon during the case.The main advantage of this technique is to allow the surgeon to visualize the lesion intradurally before opening dura in the real time. Before beginning the procedure, perform a Magnetic Resonance Imaging, or MRI scan, to identify the spinal lesion. After general anesthesia administration, position the patient so the back is exposed, and sterilize the surgical area with a povidone-iodine scrub.Next, use a scalpel to make an incision along the length of the spine over the appropriate vertebrae levels. Continuing the incision down through the tissue until the bone is reached. Perform a subperiosteal dissection by electrosurgical cautery and expose the spinous process.Turn the cutting edge of the cautery ventrally, and sweep it across the laminar, and use a combination of a Lexer bone plier and a high speed drill to remove the bony lamina and spinous process to expose the ligamentum flavum underneath. Use an angled curette and Karrison bone punch to remove the ligamentum flavum to reveal the dura mater underneath. Then use a bipolar and hemostatic matrix to achieve hemostasis.After the bony removal and dura exposure, fill the surgical field with 100 to 500 Ml saline solution such that an ultrasound tranducer probe with a 20 mm diameter can be submerged. Turn on the mobile ultrasound machine and place the ultrasound probe within the saline bath at the level of interest to begin acquiring images. To visualize the spinal cord and the lesion similar to the sagittal images from the MRI move the probe in line with the direction of the spinal canal and acquire realtime images in the longitudinal plane.To visualize the spinal cord and the lesion, like the axial images from the MRI, place the probe perpendicular to the spinal canal and acquire real-time images in the transverse plane. Then acquire real-time images to verify the location of any lesions that cannot be directly visualized to correlate with the preoperative computer tomography or MRI images to guide the surgical tool placement, and/or to confirm the resolution of the pathology. Preoperative imaging approximates the location of an intradural mass with respect to its known adjacent structures.Here, the intraoperative ultrasound correlated with the preoperative MRI imaging revealing a fluid collection above the lesion site. An axial intraoperative ultrasound showed the mass encompassing the majority of the spinal cord and a 0.5 by 0.5 centimeter piece of sterile compressed sponge was used to confirm the card limit of the tumor. A post resection intraoperative ultrasound was then obtained to confirm a complete removal of the tumor and the resolution of the mass effect.In asymptomatic thoracic disc herniation, resection by a posterior approach an intraoperative ultrasound aided in evaluating the decompression and ensuring that all of the compressive disc fragments were excised. Similarly, in the case of a lumbar burst fracture, an intraoperative ultrasound was useful in confirming an adequate decompression and the removal of all of the fragments. So while performing the intra ultrasound for spine surgeries, is important to be patient and provide a wider view for the area and use a big probe to obtain a clean imaging.Take the patient to obtain nice clean axial and sagittal view of the spinal cord so that the relationship between the spinal cord and the tumor or the lesion is cleanly defined with the ultrasound images.

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4.4K visualizações.  Harvard Medical School. O ultrassom intraoperatório para cirurgia na coluna vertebral é muito útil para patologia intradural ou patologia da medula espinhal ventral que permite ao cirurgião visualizar a lesão antes de abrir a dura. Isso também ajuda o cirurgião a localizar onde está a lesão e também a confirmar a descompressão adequada da medula espinhal após a remoção da lesão, remoção do tumor. Ele fornece a informação em tempo real que é muito, muito útil para o cirurgião da coluna vertebral...