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 data consistent with thoracic myelopathy.</li>
	<li>Exclude patients based on the following criteria: the presence of cervical spinal stenosis or lumbar spinal stenosis (confirmed by MRI), thoracic disk herniation or ossification of the posterior longitudinal ligament (confirmed by CT), fracture, or an infection or tumor of the spine.</li>
	<li>Place the patient in a prone position under general anesthesia.</li>
	<li>Conduct neurophysiological monitoring involving somatosensory evoked potentials (SSEPs) and motor-evoked potentials (MEPs) throughout the surgery.</li>
	<li>Identify the TOLF levels with the C-arm before the operation.</li>
</ol>
2. Incision and approach
<ol>
	<li>Disinfect the surgical area using povidone-iodine (PVP-I), and drape the area with sterile surgical towels.</li>
	<li>Identify the involved levels of the TOLF preoperatively using the C-arm X-ray machine.</li>
	<li>Make a longitudinal midline incision over the spinous processes using a scalpel, extending from the spinous process above to the spinous process below the level of the TOLF. 
	NOTE: One segment is about 10 cm long. The incision should extend from the spinous process above to the spinous process below the level of the TOLF.</li>
	<li>Expose the posterior bony structure, including the spinous processes, bilateral lamina, and zygapophyseal joints of the involved levels using a unipolar electrotome.</li>
	<li>Determine the pedicle screw entry points (the intersection between the midlines of the facet joint and transverse process). Insert pedicle marker pins to mark the pedicle screw entry points, and use these as a reference for the lateral border of the thoracic spinal cord.</li>
	<li>Define a rectangular decompression zone as the area between the midpoint of the facet joints bilaterally and between the inferior portions of the superior lamina (beneath the caudal edge of the pedicle, which can be located by the pedicle marker pins) and the superior portions of the inferior lamina (above the cranial edge of the pedicle) of the involved TOLF segments (Figure 3).</li>
</ol>
3. Decompression
<ol>
	<li>Remove the spinous processes, along with the supraspinous and interspinous ligaments, using a bone rongeur from the cranial to the caudal end of the decompression zone. Usually, maintain a part of the spinous process to help in removing the lamina.
	<ol>
		<li>Irrigate the incision with saline to identify bleeding sites, and block any bleeding sites with sterilized medical styptic gauge on the residual supraspinous.</li>
	</ol>
	</li>
	<li>Use an ultrasonic osteotome to cut the lamina horizontally on the cranial and the caudal ends of the decompression zone and longitudinally between the midpoint of the facet joints bilaterally. Perform the cutting until the surgeon feels the lamina has been cut through (The cutting can be done multiple times).</li>
	<li>Use a conventional osteotome to lever the lamina upward and turn it from side to side. A cracking sound of the bone indicates that the lamina has been completely cut off (Figure 4).</li>
	<li>After the lamina has been loosened, use one or two towel clamps to clamp the root of the spinous process, and elevate the entire lamina carefully. When there is adhesion between the ossified tissue and the dura mater, use a nerve dissector for disattachment.</li>
	<li>Trim the remaining articular process and the edge of the lamina on both sides with Kerrison rongeurs to ensure full decompression.</li>
</ol>
4. Internal fixation
<ol>
	<li>After thorough hemostasis with bipolar electrocoagulation and styptic cream, cover the dural surface with a gelatin sponge, or fluid gelatin, and neurosurgical sponge (e.g., Cottonoid). Then, replace the pedicle marker pins with pedicle screws.</li>
	<li>Connect the screws with titanium rods, and tighten the screw nuts.</li>
	<li>Mince the bone fragments from the vertebral lamina, and implant the fragments bilaterally between the transverse processes. Throughout the operation, achieve hemostasis using bipolar electrocoagulation and styptic cream.</li>
</ol>
5. Postoperative treatment
<ol>
	<li>Perform Jackson-Pratt drainage routinely for 24-48 h in patients without dural tears14. Administer dehydration management and neurotrophic medications after the operation.</li>
	<li>Administer intravenous methylprednisolone (40 mg) for 3 days.</li>
	<li>Instruct the patients to perform rehabilitation exercises to help functional recovery.</li>
</ol>

<ol>
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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. 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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. 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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. 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The authors have nothing to disclose.

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 ...

laminectomy-for-removal-thoracic-ossification-ligamentum-flavum-tolf

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2.5K Views.  Zhejiang University. 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.

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

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 ...

Collection and Extraction of Saliva DNA for Next Generation Sequencing

The preferred source of DNA in human genetics research is blood, or cell lines derived from blood, as these sources yield large quantities of high quality DNA. However, DNA extraction from saliva can yield high quality DNA with little to no degradation/fragmentation that is suitable for a variety of DNA assays without the expense of a phlebotomist and can even be acquired through the mail. However, at present, no saliva DNA collection/extraction protocols for next generation sequencing have been presented in the literature. This protocol optimizes parameters of saliva collection/storage and DNA extraction to be of sufficient quality and quantity for DNA assays with the highest standards, including microarray genotyping and next generation sequencing.

DNA extraction from saliva can provide a readily available source of high molecular weight DNA, with little to no degradation/fragmentation. This protocol provides optimized parameters for saliva collection/storage and DNA extraction to be of sufficient quality and quantity for downstream DNA assays with high quality requirements.

The preferred source of DNA in human genetics research is blood, or cell lines derived from blood, as these sources yield large quantities of high quality ...

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.

We describe methods for longitudinal monitoring of the efficacy of therapeutics for the treatment of colonic pathologies in mice using a rigid endoscope. This protocol can be readily used for the characterization of the therapeutic response of an individual tumor in live mice and also for monitoring potential disease relapse.

Animal models of inflammatory bowel disease (IBD) and colorectal cancer (CRC) have provided significant insight into the cell intrinsic and extrinsic ...

Surgical Models of Gastroesophageal Reflux with Mice

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 ...

Assessment of Sarcoplasmic Reticulum Calcium Reserve and Intracellular Diastolic Calcium Removal in Isolated Ventricular Cardiomyocytes

Intracellular calcium recycling plays a critical role in regulation of systolic and diastolic function in cardiomyocytes. Cardiac sarcoplasmic reticulum (SR) serves as a Ca2+ reservoir for contraction, which reuptakes intracellular Ca2+ during relaxation. The SR Ca2+ reserve available for beats is determinate for cardiac contractibility, and the removal of intracellular Ca2+ is critical for cardiac diastolic function. Under some pathophysiological conditions, such as diabetes and heart failure, impaired calcium clearance and SR Ca2+ store in cardiomyocytes may be involved in the progress of cardiac dysfunction. Here, we describe a protocol to evaluate SRCa2+ reserve and diastolic Ca2+ removal. Briefly, a single cardiomyocyte was enzymatically isolated, and the intracellular Ca2+ fluorescence indicated by Fura-2 was recorded by a calcium imaging system. To employ caffeine for inducing total SR Ca2+ release, we preset an automatic perfusion switch program by interlinking the stimulation system and the perfusion system. Then, the mono-exponential curve fitting was used for analyzing decay time constants of calcium transients and caffeine-induced calcium pulses. Accordingly, the contribution of the SR Ca2+-ATPase (SERCA) and Na+-Ca2+ exchanger (NCX) to diastolic calcium removal was evaluated.

Intracellular calcium recycling plays a critical role in regulation of systolic and diastolic function in cardiomyocytes. Here, we describe a protocol to evaluate sarcoplasmic reticulum Ca2+ reserve and diastolic calcium removal function in cardiomyocytes by a calcium imaging system.

Intracellular calcium recycling plays a critical role in regulation of systolic and diastolic function in cardiomyocytes. Cardiac sarcoplasmic reticulum ...

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 ...