Name: laminectomy for the removal of thoracic ossification of the ligamentum flavum (tolf) using ultrasonic and conventional osteotomes
Uploaded: 2023-04-21T12:20:00
Description: Watch this Scientific Journal Video about Laminectomy for the Removal of Thoracic Ossification of the Ligamentum Flavum TOLF Using Ultrasonic and Conventional Osteotomes at JoVE.com

Funding was provided by the Zhejiang Medical and Health Science and Technology project (project numbers: 2021433841 and 2023564481).

Ethical approval was obtained from the Medical Ethics Committee of the authors&#39; hospital. Informed consent was obtained from each patient.
1. Inclusion/exclusion criteria and preoperative preparation
<ol>
	<li>Include patients with the following preoperative symptoms: unable to walk steadily, numbness of the lower limbs, atrophy of the lower limbs, leg weakness, uncontrolled movement of the lower extremities, or sphincter dysfunction, etc., as well as signs and imaging d...

<ol>
	<li>Miura, K., 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=Thoracic+myelopathy+caused+by+calcification+of+the+ligamentum+flavum.">Thoracic myelopathy caused by calcification of the ligamentum flavum.</a> Journal of Rural Medicine. 15 (2), 65-67 (2020).</li><li>Wang, T., Yin, C., Wang, D., Li, S., Chen, X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Surgical+technique+for+decompression+of+severe+thoracic+myelopathy+due+to+tuberous+ossification+of+ligamentum+flavum.">Surgical technique for decompression of severe thoracic myelopathy due to tuberous ossification of ligamentum flavum.</a> Clinical Spine Surgery. 30 (1), 7-12 (2017).</li><li>Baba, S., 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=Microendoscopic+posterior+decompression+for+the+treatment+of+thoracic+myelopathy+caused+by+ossification+of+the+ligamentum+flavum:+A+technical+report.">Microendoscopic posterior decompression for the treatment of thoracic myelopathy caused by ossification of the ligamentum flavum: A technical report.</a> European Spine Journal. 25 (6), 1912-1919 (2016).</li><li>Ahn, D. K., 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=Ossification+of+the+ligamentum+flavum.">Ossification of the ligamentum flavum.</a> Asian Spine Journal. 8 (1), 89-96 (2014).</li><li>Isaacs, R. E., 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=Minimally+invasive+microendoscopy-assisted+transforaminal+lumbar+interbody+fusion+with+instrumentation.">Minimally invasive microendoscopy-assisted transforaminal lumbar interbody fusion with instrumentation.</a> Journal of Neurosurgery. Spine. 3 (2), 98-105 (2005).</li><li>Li, K. K., Chung, O. M., Chang, Y. P., So, Y. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Myelopathy+caused+by+ossification+of+ligamentum+flavum.">Myelopathy caused by ossification of ligamentum flavum.</a> Spine. 27, 308-312 (2002).</li><li>Okada, K., 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=Thoracic+myelopathy+caused+by+ossification+of+the+ligamentum+flavum.+Clinicopathologic+study+and+surgical+treatment.">Thoracic myelopathy caused by ossification of the ligamentum flavum. Clinicopathologic study and surgical treatment.</a> Spine. 16 (3), 280-287 (1991).</li><li>Ikuta, K., 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=Decompression+procedure+using+a+microendoscopic+technique+for+thoracic+myelopathy+caused+by+ossification+of+the+ligamentum+flavum.">Decompression procedure using a microendoscopic technique for thoracic myelopathy caused by ossification of the ligamentum flavum.</a> Minimally Invasive Neurosurgery. 54 (5-6), 271-273 (2011).</li><li>Osman, N. S., 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=Outcomes+and+complications+following+laminectomy+alone+for+thoracic+myelopathy+due+to+ossified+ligamentum+flavum:+A+systematic+review+and+meta-analysis.">Outcomes and complications following laminectomy alone for thoracic myelopathy due to ossified ligamentum flavum: A systematic review and meta-analysis.</a> Spine. 43 (14), 842-848 (2018).</li><li>Hou, X., 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=A+systematic+review+of+complications+in+thoracic+spine+surgery+for+ossification+of+ligamentum+flavum.">A systematic review of complications in thoracic spine surgery for ossification of ligamentum flavum.</a> Spinal Cord. 56 (4), 301-307 (2018).</li><li>Hu, X., Ohnmeiss, D. D., Lieberman, I. H. <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+an+ultrasonic+osteotome+device+in+spine+surgery:+experience+from+the+first+128+patients.">Use of an ultrasonic osteotome device in spine surgery: experience from the first 128 patients.</a> European Spine Journal. 22 (12), 2845-2849 (2013).</li><li>Florence, J. 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=Intrarater+reliability+of+manual+muscle+test+(Medical+Research+Council+scale)+grades+in+Duchenne's+muscular+dystrophy.">Intrarater reliability of manual muscle test (Medical Research Council scale) grades in Duchenne's muscular dystrophy.</a> Physical Therapy. 72 (2), 115 (1992).</li><li>Kumar, S. P., Ramasubramanian, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Babinski+sign--A+reappraisal.">The Babinski sign--A reappraisal.</a> Neurology India. 48 (4), 314-318 (2000).</li><li>Liu, T., 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=Analysis+of+the+surgical+strategy+and+postoperative+clinical+effect+of+thoracic+ossification+of+ligament+flavum+with+dural+ossification.">Analysis of the surgical strategy and postoperative clinical effect of thoracic ossification of ligament flavum with dural ossification.</a> Frontiers in Surgery. 9, 1036253 (2022).</li><li>Li, X., 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=Surgical+results+and+prognostic+factors+following+percutaneous+full+endoscopic+posterior+decompression+for+thoracic+myelopathy+caused+by+ossification+of+the+ligamentum+flavum.">Surgical results and prognostic factors following percutaneous full endoscopic posterior decompression for thoracic myelopathy caused by ossification of the ligamentum flavum.</a> Scientific Reports. 10, 1305 (2020).</li><li>Hosono, N., 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=Potential+risk+of+thermal+damage+to+cervical+nerve+roots+by+a+high-speed+drill.">Potential risk of thermal damage to cervical nerve roots by a high-speed drill.</a> The Journal of Bone and Joint Surgery. British Volume. 91 (11), 1541-1544 (2009).</li><li>Hara, M., Takayasu, M., Takagi, T., Yoshida, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=En+bloc+laminoplasty+performed+with+threadwire+saw.">En bloc laminoplasty performed with threadwire saw.</a> Neurosurgery. 48 (1), 235-239 (2001).</li><li>Vercellotti, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Technological+characteristics+and+clinical+indications+of+piezoelectric+bone+surgery.">Technological characteristics and clinical indications of piezoelectric bone surgery.</a> Minerva Stomatologica. 53 (5), 207-214 (2004).</li><li>Nickele, C., Hanna, A., Baskaya, M. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Osteotomy+for+laminoplasty+without+soft+tissue+penetration,+performed+using+a+harmonic+bone+scalpel:+Instrumentation+and+technique.">Osteotomy for laminoplasty without soft tissue penetration, performed using a harmonic bone scalpel: Instrumentation and technique.</a> Journal of Neurological Surgery. Part A, Central European Neurosurgery. 74 (3), 183-186 (2013).</li><li>Sanborn, M. R., 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=Safety+and+efficacy+of+a+novel+ultrasonic+osteotome+device+in+an+ovine+model.">Safety and efficacy of a novel ultrasonic osteotome device in an ovine model.</a> Journal of Clinical Neuroscience. 18 (11), 1528-1533 (2011).</li><li>Schaeren, S., 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=Assessment+of+nerve+damage+using+a+novel+ultrasonic+device+for+bone+cutting.">Assessment of nerve damage using a novel ultrasonic device for bone cutting.</a> Journal of Oral and Maxillofacial Surgery. 66 (3), 593-596 (2008).</li><li>St&#252;binger, S., Kuttenberger, J., Filippi, A., Sader, R., Zeilhofer, H. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intraoral+piezosurgery:+Preliminary+results+of+a+new+technique.">Intraoral piezosurgery: Preliminary results of a new technique.</a> Journal of Oral and Maxillofacial Surgery. 63 (9), 1283-1287 (2005).</li><li>Vercellotti, T., Pollack, A. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+new+bone+surgery+device:+Sinus+grafting+and+periodontal+surgery.">A new bone surgery device: Sinus grafting and periodontal surgery.</a> Compendium of Continuing Education in Dentistry. 27 (5), 319-325 (2006).</li></ol>

Laminectomy is the conventional treatment method for thoracic ossified ligamentum flavum. However, the improper use of traditional bone-cutting equipment, such as high-speed drills and revolving burrs, can result in nerve thermal injury, grasping the soft tissue, tearing the dura mater, and mechanical injury15,16,17. An ultrasonic osteotome is a novel bone-cutting tool used for precise osteotomies. This device allows for bone di...

Thoracic ossification of the ligamentum flavum (TOLF) is one of the major causes of thoracic spinal stenosis and has been established as the primary cause of thoracic myelopathy1,2,3. TOLF is characterized by the replacement of the ligamentum flavum by ectopic new bone formation. The incidence of TOLF is as high as 36% in Japan and 63.9% in China. Most patients show slow progression to symptomatic thoracic canal stenosis or thoracic myelopathy4. Decompression is the only effective treatment for TOLF once it becomes symptomatic since conservative treatment is usually ineffective5.
Laminoplasty, laminectomy, and lamina fenestration are three surgical techniques that have been demonstrated to be effective for TOLF6,7,8. However, the surgical outcomes are not always satisfactory. The conventional methods can result in a high rate of perioperative complications such as dural laceration and/or iatrogenic spinal cord injury9,10. Therefore, it is important to develop a more efficient and secure surgical technique for TOLF.
Here, we describe in detail a method for laminectomy of the thoracic spine using an ultrasonic osteotome combined with a conventional osteotome to resect the lamina (Figure 1). An ultrasonic osteotome is a precision tool that uses ultrasonic oscillations in its blade to selectively cut mineralized tissue, preventing collateral tissue damage11. The technique presented herein is a relatively safe and easy-to-learn method that should be recommended for the treatment of TOLF.
An ultrasonic osteotomy system is designed to cut hard bone structures effectively while preserving soft tissues by converting the electrical input signal into vertically mechanical oscillations at an amplitude of 0-120 &#181;m and a frequency of 39 kHz. The system consists of a power unit, a handpiece, several tips, and a footswitch. An irrigation pump is also integrated into the system, and this delivers saline to the cutting edge to reduce local thermal necrosis.
Presented here is a case of 57 year old male patient who presented with lower limb weakness with unsteady walking for 3 years. The symptoms were more pronounced on the right side. Physical examination revealed that the patient&#39;s muscle strength grade12 was 5 (barely detectable weakness) for both the lower limbs. Additionally, numbness of the skin occurred when acupuncture was applied below the left inguinal plane, hypoesthesia was observed when needling the skin in the saddle area, the deep tendon reflexes were slightly increased in both lower limbs, and the Babinski sign13 was positive. X-ray, CT, and MRI showed thoracic ossification of the ligamentum flavum at T10-11. The preoperative data are presented in Figure 2.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>C-arm X-ray machine</td>
			<td>GE&#160;</td>
			<td>20192060063</td>
			<td>/</td>
		</tr>
		<tr>
			<td>Cera styptica</td>
			<td>Johnson&#38;Johnson (China) Medical Equipment Co., Ltd</td>
			<td>W810T</td>
			<td>/</td>
		</tr>
		<tr>
			<td>Conventional osteotome</td>
			<td>Suzhou qingniu medical instrument co.</td>
			<td>10012.01</td>
			<td>/</td>
		</tr>
		<tr>
			<td>Cottonoids</td>
			<td>Piaoan Holding Group Co., Ltd</td>
			<td>20182640073</td>
			<td>/</td>
		</tr>
		<tr>
			<td>Fluid gelatin</td>
			<td>Johnson&#38;Johnson (China) Medical Equipment Co., Ltd</td>
			<td>20183142459</td>
			<td>/</td>
		</tr>
		<tr>
			<td>Gelatin sponge</td>
			<td>B.Braun Melsungen AG&#160;</td>
			<td>20163642299</td>
			<td>/</td>
		</tr>
		<tr>
			<td>Jackson&#8211;Pratt drainage</td>
			<td>Suzhou Weikang Medical Equipment Co., Ltd</td>
			<td>20162140955</td>
			<td>/</td>
		</tr>
		<tr>
			<td>Kerrison Rongeurs</td>
			<td>Jinzhong Medical Instruments Co., Ltd</td>
			<td>2100888</td>
			<td>/</td>
		</tr>
		<tr>
			<td>Nerve dissector</td>
			<td>Jinzhong Medical Instruments Co., Ltd</td>
			<td>p23110</td>
			<td>/</td>
		</tr>
		<tr>
			<td>Pedicle screw</td>
			<td>Medtronic</td>
			<td>76446545</td>
			<td>/</td>
		</tr>
		<tr>
			<td>Towel clamps</td>
			<td>KEWEIDUN</td>
			<td>10058468134417&#160;&#160;&#160;</td>
			<td>/</td>
		</tr>
		<tr>
			<td>Ultrasonic Osteotomy Surgical System</td>
			<td>SMTP Technology Co.</td>
			<td>FD880A</td>
			<td>/</td>
		</tr>
		<tr>
			<td>Unipolar/bipolar electrotome</td>
			<td>Shanghai Hutong Electronics Co., Ltd&#160;</td>
			<td>20143251899</td>
			<td>/</td>
		</tr>
	</tbody>
</table>

laminectomy for the removal of thoracic ossification of the ligamentum flavum (tolf) using ultrasonic and conventional osteotomes

Thoracic ossification of the ligamentum flavum (TOLF) is a common cause of progressive thoracic myelopathy. TOLF is typically treated with surgical decompression. A variety of surgical techniques, including laminoplasty, laminectomy, and lamina fenestration, are used for the effective treatment of TOLF. However, traditional methods are associated with a substantial risk of perioperative complications, including dural laceration and/or iatrogenic spinal cord injury. Therefore, it is important to develop an efficient and secure surgical technique for TOLF. Herein, we describe a method for laminectomyperformed at the thoracic spine using an ultrasonic osteotome combined with a conventional osteotome. This technique can reduce intraoperative complications. This is a relatively safe and easy-to-learn method that should be recommended for the treatment of TOLF.

Representative case results 
On the first postoperative day, the CT scans revealed that the ossification had been fully removed, and the spinal cord had been completely decompressed (Figure 5). The patient could walk steadily. The muscle strength of both lower limbs was 5. The patient was discharged 3 days after the operation.
A total of 71 patients were enrolled in the study. All surgeries were carried out satisfactorily. The mean duration o...

Watch this Scientific Journal Video about Laminectomy for the Removal of Thoracic Ossification of the Ligamentum Flavum TOLF Using Ultrasonic and Conventional Osteotomes at JoVE.com

Laminectomy for the Removal of Thoracic Ossification of the Ligamentum Flavum TOLF Using Ultrasonic and Conventional Osteotomes

We present a methodology for using an ultrasonic osteotome combined with a conventional osteotome for laminectomy in thoracic ossification of the ligamentum flavum. This is a relatively safe and easy-to-learn method that avoids the perioperative complications associated with the conventional method.

Laminectomy for the Removal of Thoracic Ossification of the Ligamentum Flavum (TOLF) Using Ultrasonic and Conventional Osteotomes

Thoracic ossification of the ligamentum flavum (TOLF) is a common cause of progressive thoracic myelopathy. TOLF is typically treated with surgical ...

In this video we'll share a case using laminectomy for the removal of thoracic ossification of the ligamentum flavum using ultrasonic and conventional osteotome. Thoracic ossification of the ligamentum flavum is a well-known cause of thoracic spinal stenosis that has been identified as a primary cause of thoracic myelopathy. The conservative treatment is generally ineffective, so once the TOLF is symptomatic, decompression is almost the only effective method.Several types of surgical methods has been shown to be effective for TOLF including laminoplasty, laminectomy, and lamina fenestration. There's a high rate of perioperative complications, such as dural laceration and/or iatrogenic spinal cord injury. Here, we report in detail a method for laminectomy in thoracic spine using ultrasonic osteotome combined with conventional osteotome to resect the lamina, which is effective and safer for the treatment of TOLF.Ethical approval was obtained from the Medical Ethics Committee of the author's hospital, and informed the consent was obtained from each patient. Here is a brief history of the patient. And we find ossification of the ligamentum flavum between T10 and 11.Under general anesthesia, the patient was placed in prone position. Neurophysiological monitoring involving SSEPs and MEPs was conducted throughout the surgery. The TOLF levels were identified with a C-arm before operation.Surgery area was disinfected using PVP-I, and draped with sterile surgical towels. They involved the levels of TOLF were identified intra-operatively via a C-arm X-ray machine. A longitudinal midline incision was made over the spinous process extending from the spinous process above to the spinous process below the level of pathology.The posterior bony structure including the spinous processes, bilateral lamina, and zygapophyseal joints of the involved levels were exposed using unipolar electrotome. The pedicle screw entry points were determined based on anatomical landmarks according to the AO method, which is the intersection between the midlines of the facet joint and transverse process. Pedicle marker pins were inserted to mark the pedicle screw entry points, and also used as a reference for the lateral border of the thoracic spinal cord.The spinous processes, along with the supraspinous and interspinous ligaments were then removed using a bone rongeur from the cranial to the caudal end of the decompression zone. Usually a part of the spinous process was maintained to help removing the lamina. The incision was irrigated with saline to identify bleeding sites, a sterilized medical cera sryptica was used for hemostasis on the residual supraspinous.A rectangular decompression zone was identified as a area between the midpoints of the facet joints bilaterally and between the inferior portions of the superior lamina and superior portions of the inferior lamina of the TOLF involved segments. The ultrasonic osteotome was used to cut the lamina horizontally on cranial and the caudal ends of the decompression zone. And longitudinally between the midpoints of the facet joints bilaterally.The cutting can be performed for multiple times until your feeling the lamina is cutting through. The conventional osteotome was used to lever the lamina upwards in turn from side to side. The bounce sound of the bone indicates the lamina has been completely cut off.After lamina was loosened, one or two towel clamps were used to clamp the root of the spinous process, and the entire lamina is elevated carefully. When there is adhesion between the ossified tissue and the dura matter, a nerve dissector can be used for this attachment. The remaining articular process and the edge of the lamina on both sides were further detected and trimmed using Kerrison Rongeur to ensure fully decompression.After thoroughly hemostasis with bipolar electrocoagulation and cera styptica, the dural surface was covered with gelatin sponge or fluid gelatin, and cottonoids. Then, the pedicle marker pins were replaced by pedicle screws. In some cases, the bone fragments from the vertebral lamina were minced and implanted bilaterally between the transverse processes.Titanium rods were connected and screw nuts were tightened. Throughout the operation, hemostasis were achieved using bipolar electrocoagulation and cera styptica. Jackson-Pratt drainage was routinely performed for 24 to 48 hours in patient without the dura tears.Dehydration management and neurotrophic medications were administered after the operation. Intravenous methylprednisone was administrated for three days. Patients were instructed to perform rehabilitation exercise to help functional recovery.The muscle strength was improved remarkably and the patient was discharged three days after operation. On the first postoperative day CD scans revealed that the ossification has been fully removed and the spinal cord has been completely decompressed. For the whole 71 patients, no catastrophic complications, such as major vascular injury, spinal cord injury, or pleural effusion formation occurred during surgery.The CT result on the first postoperative day confirmed that the ossification was completely resected and that spinal cord decompression was sufficient. The bone structure can be selectively removed without damaging the adjacent nerve tissue, due to the precise oscillations of the ultrasonic blade. Combined with careful removal of the lamina with the use of osteotome and towel clamps mentioned above, the low operation time, low blood loss, low complication rate was achieved.In conclusion, based on the result of the current study, ultrasonic osteotome combined with conventional osteotome to resect the lamina for laminectomy has been shown as an effective, safe, and feasible option for the treatment of thoracic ossification of the ligamentum flavum.

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Clinical Testing and Spinal Cord Removal in a Mouse Model for Amyotrophic Lateral Sclerosis (ALS)

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder resulting in progressive degeneration of motoneurons. Peak of onset is around 60 years for the sporadic disease and around 50 years for the familial disease. Due to its progressive course, 50% of the patients die within 30 months of symptom onset. In order to evaluate novel treatment options for this disease, genetic mouse models of ALS have been generated based on human familial mutations in the SOD gene, such as the SOD1 (G93A) mutation. Most important aspects that have to be evaluated in the model are overall survival, clinical course and motor function. Here, we demonstrate the clinical evaluation, show the conduction of two behavioural motor tests and provide quantitative scoring systems for all parameters. Because an in depth analysis of the ALS mouse model usually requires an immunohistochemical examination of the spinal cord, we demonstrate its preparation in detail applying the dorsal laminectomy method. Exemplary histological findings are demonstrated. The comprehensive application of the depicted examination methods in studies on the mouse model of ALS will enable the researcher to reliably test future therapeutic options which can provide a basis for later human clinical trials.

Clinical Testing and Spinal Cord Removal in a Mouse Model for Amyotrophic Lateral Sclerosis ALS

A mouse model for amyotrophic lateral sclerosis (ALS) is examined clinically and behaviorally. As a prerequisite for an accompanying immunohistological analysis the preparation of the spinal cord is depicted in detail.

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder resulting in progressive degeneration of motoneurons. Peak of onset is around 60 ...

Ultrasonic Assessment of Myocardial Microstructure

Echocardiography is a widely accessible imaging modality that is commonly used to noninvasively characterize and quantify changes in cardiac structure and function. Ultrasonic assessments of cardiac tissue can include analyses of backscatter signal intensity within a given region of interest. Previously established techniques have relied predominantly on the integrated or mean value of backscatter signal intensities, which may be susceptible to variability from aliased data from low frame rates and time delays for algorithms based on cyclic variation. Herein, we describe an ultrasound-based imaging algorithm that extends from previous methods, can be applied to a single image frame&#160;and accounts for the full distribution of signal intensity values derived from a given myocardial sample. When applied to representative mouse and human imaging data, the algorithm distinguishes between subjects with and without exposure to chronic afterload resistance. The algorithm offers an enhanced surrogate measure of myocardial microstructure and can be performed using open-access image analysis software.

Echocardiography is commonly used to noninvasively characterize and quantify changes in cardiac structure and function. We describe an ultrasound-based imaging algorithm that offers an enhanced surrogate measure of myocardial microstructure and can be performed using open-access image analysis software.

Echocardiography is a widely accessible imaging modality that is commonly used to noninvasively characterize and quantify changes in cardiac structure and ...

Non-invasive Assessment of the Efficacy of New Therapeutics for Intestinal Pathologies Using Serial Endoscopic Imaging of Live Mice

Animal models of inflammatory bowel disease (IBD) and colorectal cancer (CRC) have provided significant insight into the cell intrinsic and extrinsic mechanisms that contribute to the onset and progression of intestinal diseases. The identification of new molecules that promote these pathologies has led to a flurry of activity focused on the development of potential new therapies to inhibit their function. As a result, various pre-clinical mouse models with an intact immune system and stromal microenvironment are now heavily used. Here we describe three experimental protocols to test the efficacy of new therapeutics in pre-clinical models of (1) acute mucosal damage, (2) chronic colitis and/or colitis-associated colon cancer, and (3) sporadic colorectal cancer. We also outline procedures for serial endoscopic examination that can be used to document the therapeutic response of an individual tumor and to monitor the health of individual mice. These protocols provide complementary experimental platforms to test the effectiveness of therapeutic compounds shown to be well tolerated by mice.

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Multiple surgical procedures have been reported to induce gastroesophageal reflux in animals. Herein, we report three surgical models with mice aiming to induce reflux of gastric contents, duodenal contents or mixed contents. Surgical procedures and general principles have been described in detail. A researcher with surgical experience should be able to grasp the technique after a short period of practice. After surgery, most mice can survive and develop reflux esophagitis similar to that in humans. However, it should be noted that histological differences between mouse and human esophagus are the inherent limitations of these surgical models. If used for research on Barrett&#8217;s esophagus and adenocarcinoma, these procedures may need to be combined with genetic modifications.

This article demonstrates surgical procedures of gastroesophageal reflux with mice. These models are useful tools for research on mechanisms and treatment of gastroesophageal reflux disease and potentially Barrett&#8217;s esophagus and esophageal adenocarcinoma.

Multiple surgical procedures have been reported to induce gastroesophageal reflux in animals. Herein, we report three surgical models with mice aiming to ...

Chronic Thromboembolic Pulmonary Hypertension and Assessment of Right Ventricular Function in the Piglet

An original piglet model of Chronic Thromboembolic Pulmonary Hypertension (CTEPH) associated with chronic Right Ventricular (RV) dysfunction is described. Pulmonary Hypertension (PH) was induced in 3-week-old piglets by a progressive obstruction of the pulmonary vascular bed. A ligation of the left Pulmonary Artery (PA) was performed first through a mini-thoracotomy. Second, weekly embolizations of the right lower pulmonary lobe were done under fluoroscopic guidance with n-butyl-2-cyanoacrylate during 5 weeks. Mean Pulmonary Arterial Pressure (mPAP) measured by ritght heart catheterism, increased progressively, as well as Right Atrial pressure and Pulmonary Vascular Resistances (PVR) after 5 weeks compared to sham animals. Right Ventricular (RV) structural and functional remodeling were assessed by transthoracic echocardiography (RV diameters, RV wall thickness, RV systolic function). RV elastance and RV-pulmonary coupling were assessed by Pressure-Volume Loops (PVL) analysis with conductance method. Histologic study of the lung and the right ventricle were also performed. Molecular analyses on RV fresh tissues could be performed through repeated transcutaneous endomyocardial biopsies. Pulmonary microvascular disease in obstructed and unobstructed territories was studied from lung biopsies using molecular analyses and pathology. Furthermore, the reliability and the reproducibility was associated with a range of PH severity in animals. Most aspects of the human CTEPH disease were reproduced in this model, which allows new perspectives for the understanding of the underlying mechanisms (mitochondria, inflammation) and new therapeutic approaches (targeted, cellular or gene therapies) of the overloaded right ventricle but also pulmonary microvascular disease.

Chronic Thromboembolic Pulmonary Hypertension (CTEPH) and Right Ventricular (RV) dysfunction were induced in piglets by progressive obstruction of the pulmonary arteries. Consequences were remarkably similar to those observed in CTEPH patients. This animal model would be a very useful tool for pathophysiology and therapeutic experiments on CTEPH and RV failure.

An original piglet model of Chronic Thromboembolic Pulmonary Hypertension (CTEPH) associated with chronic Right Ventricular (RV) dysfunction is described. ...

Intravital Microscopy and Thrombus Induction in the Earlobe of a Hairless Mouse

Thrombotic complications of vascular diseases are one leading cause of morbidity and mortality in industrial nations. Due to the complex interactions between cellular and non-cellular blood components during thrombus formation, reliable studies of the physiology and pathophysiology of thrombosis can only be performed in vivo. Therefore, this article presents an ear model in hairless mice and focuses on the in vivo analysis of microcirculation, thrombus formation, and thrombus evolution. By using intravital fluorescence microscopy and the intravenous (iv) application of the respective fluorescent dyes, a repetitive analysis of microcirculation in the auricle can easily be performed, without the need for surgical preparation. Furthermore, this model can be adapted for in vivo studies of different issues, including wound healing, reperfusion injury, or angiogenesis. In summary, the ear of hairless mice is an ideal model for the in vivo study of skin microcirculation in physiological or pathophysiological conditions and for the evaluation of its reaction to different systemic or topical treatments.

The ear model of the hairless SKH1-Hrhr mouse enables intravital fluorescence microscopy of microcirculation and phototoxic thrombus induction without prior surgical preparation in the examined microvascular bed. Therefore, the ear of the hairless mouse is an excellent in vivo model to study the complex interactions during microvascular thrombus formation, thrombus evolution, and thrombolysis.

Thrombotic complications of vascular diseases are one leading cause of morbidity and mortality in industrial nations. Due to the complex interactions ...

Cardiac Magnetic Resonance for the Evaluation of Suspected Cardiac Thrombus: Conventional and Emerging Techniques

We present the conventional cardiac magnetic resonance (CMR) protocol for evaluating a suspected thrombus and highlight emerging techniques.&#160;The appearance of a mass on certain magnetic resonance (MR) sequences can help differentiate a thrombus from competing diagnoses such as a tumor. T1 and T2 signal characteristics of a thrombus are related to the evolution of hemoglobin properties. A thrombus typically does not enhance following contrast administration, which also helps differentiation from a tumor. We also highlight the emerging role of T1 mapping in the evaluation of a thrombus, which can add another level of support in diagnosis. Prior to any CMR exam, patient screening and interviews are critical to ensure safety and to optimize patient comfort. Effective communication during the exam between the technologist and the patient promotes proper breath holding technique and higher quality images. Volumetric post processing and structured reporting are helpful to ensure that the radiologist answers the ordering services&#39; question and communicates these results effectively. Optimal pre-MR safety evaluation, CMR exam execution, and post exam processing and reporting allow for delivery of high quality radiological service in the evaluation of a suspected cardiac thrombus.

The goal of this article is to describe how cardiac magnetic resonance can be used for the evaluation and diagnosis of a suspected cardiac thrombus. The method presented will describe data acquisition as well as the pre-procedure and post-procedure protocol.

We present the conventional cardiac magnetic resonance (CMR) protocol for evaluating a suspected thrombus and highlight emerging techniques.&#160;The ...

Ultrasound Imaging of the Thoracic and Abdominal Aorta in Mice to Determine Aneurysm Dimensions

Contemporary high-resolution ultrasound instruments have sufficient resolution to facilitate the measurement of mouse aortas. These instruments have been widely used to measure aortic dimensions in mouse models of aortic aneurysms. Aortic aneurysms are defined as permanent dilations of the aorta, which occur most frequently in the ascending and abdominal regions. Sequential measurements of aortic dimensions by ultrasound are the principal approach for assessing the development and progression of aortic aneurysms in vivo. Although many reported studies used ultrasound imaging to measure aortic diameters as a primary endpoint, there are confounding factors, such as probe position and cardiac cycle, that may impact the accuracy of data acquisition, analysis, and interpretation. The purpose of this protocol is to provide a practical guide on the use of ultrasound to measure the aortic diameter in a reliable and reproducible manner. This protocol introduces the preparation of mice and instruments, the acquisition of appropriate ultrasound images, and data analysis.

Ultrasound imaging has become a common modality to determine the luminal dimensions of thoracic and abdominal aortic aneurysms in mice. This protocol describes the procedure to acquire reliable and reproducible two-dimensional ultrasound images of the ascending and abdominal aorta in mice.

Contemporary high-resolution ultrasound instruments have sufficient resolution to facilitate the measurement of mouse aortas. These instruments have been ...

Transaxillary First Rib Resection for Treatment of the Thoracic Outlet Syndrome

Thoracic outlet syndrome (TOS) is a common disorder that causes a significant loss of productivity. The transaxillary first rib resection (TFRR) protocol has been used for the decompression of trapped neurovascular structures in the TOS. Among the other surgical procedures, the advantage of the TFRR is that it has the smallest rate of recurrence and better cosmetic outcomes. The disadvantage of TFRR is that it provides a narrow, and deep working corridor that makes obtaining vascular control challenging.

Here, we present a protocol of the transaxillary resection of the first rib for treatment of thoracic outlet syndrome caused by compression of the brachial plexus, subclavian vein and artery.

Thoracic outlet syndrome (TOS) is a common disorder that causes a significant loss of productivity. The transaxillary first rib resection (TFRR) protocol ...

Murine Surgical Model of Topical Elastase Induced Descending Thoracic Aortic Aneurysm

According to the Center for Disease Control, aortic aneurysms (AAs) were considered a leading cause of death in all races and both sexes from 1999-2016. An aneurysm forms as a result of progressive weakening and eventual dilation of the aorta, which can rupture or tear once it reaches a critical diameter. Aneurysms of the descending aorta in the chest, called descending thoracic aortic aneurysms (dTAA), make up a large proportion of aneurysm cases in the United States. Uncontained dTAA rupture is almost universally lethal, and elective repair has a high rate of morbidity and mortality. The purpose of our model is to study dTAA specifically, to elucidate the pathophysiology of dTAA and to search for molecular targets to halt the growth or reduce the size of dTAA. By having a murine model to study thoracic pathology precisely, targeted therapies can be developed to specifically test dTAA. The method is based on the placement of porcine pancreatic elastase (PPE) directly on the outer murine aortic wall after surgical exposure. This creates a destructive and inflammatory reaction, which weakens the aortic wall and allows for aneurysm formation over weeks to months. Though murine models possess limitations, our dTAA model produces robust aneurysms of predictable size. Furthermore, this model can be used to test genetic and pharmaceutical targets which may arrest dTAA growth or prevent rupture. In human patients, interventions such as these could help avoid aneurysm rupture, and difficult surgical intervention.

We describe a surgical protocol to consistently induce robust descending thoracic aortic aneurysms in mice. The procedure involves left thoracotomy, thoracic aorta exposure, and placement of a sponge soaked in porcine pancreatic elastase on the aortic wall.

According to the Center for Disease Control, aortic aneurysms (AAs) were considered a leading cause of death in all races and both sexes from 1999-2016. ...