这项工作得到了中国国家自然科学基金委员会（81770271:给Y，廖），中国国家自然科学基金联合基金（U1908205:给Y，廖）和广州市科技规划项目（201804020083:廖博士）的资助。

所有程序都是按照美国国家卫生研究院出版的《 实验室动物的护理和使用 指南》进行的（NIH出版物第85-23号，1996年修订）。C57BL/6J雄性小鼠（8~10周，20~25克）由南方医科大学动物中心提供。
1. 术前准备
<ol><li>用针架捏掉 25 G 针的尖端，用像支架这样的硬物将其钝化。</li>
	<li>通过针头传递一个5+0可吸收的缝合线，然后弯曲到90°与持有人13。 注:根据不同的研究目的，研究者可以选择吸收时间不同的可吸收线。在此协议中，我们使用 2 周的可吸收缝合收缩主动脉拱门。</li>
	<li>将另一根 25 G 针弯曲至 120°，并用支架平滑尖端，用作配扎步骤中的垫片。 注:25 G 针头用作体重 （BW） + 25 g 的小鼠的垫片。使用 26 G 针对小鼠与 19–24 g BW.</li>
	<li>用75%的酒精对手术现场进行消毒。</li>
	<li>将加热垫温度调整为 37 °C。</li>
	<li>准备消毒手术器械（包括1把眼科剪刀、1把微剪刀、2把微手术肘钳、1个针架和1个微型针架）。</li>
</ol>2. 麻醉和剃须的感应
<ol><li>通过在盐溶液中稀释的西拉津（5毫克/千克）和氯胺酮（100毫克/千克）的混合物（0.9%NaCl）进行腹膜注射，使小鼠麻醉。用负踏板戒断反射确认完全麻醉。</li>
	<li>通过用缝合针固定切口和用胶带固定四肢，使鼠标保持超细位置。</li>
	<li>涂抹脱毛霜，去除颈部和西福的头发。用碘对该地区进行消毒，然后用75%的酒精消毒。</li>
</ol>3. 手术
<ol><li>用手术刀在超胸缺口和胸部之间的中线位置切口超过 10 毫米。然后，将皮肤和表面筋膜分开。</li>
	<li>通过从骨部角度计算肋骨来识别第一个间距空间。在第一个间歇空间中执行切口，并尽可能靠近胸骨。用肘部钳子模糊地穿透它， 打开这个空间。</li>
	<li>轻轻地将帕奇马和胸腺分开，直到可以看到横向主动脉拱门。 注意:不要损坏胸膜，以避免肺气管。</li>
	<li>通过主动脉之间的主动脉拱门下的5–0可吸收缝合，用闩锁针14。请确保手术场内可见胸动脉、左侧普通胡萝卜动脉和左下腹动脉。</li>
	<li>将垫片放在第 1.3 步准备的隔横主动脉上，并在垫片上执行双结，并在第 3.4 步中用缝合线进行。 注意:垫片的尖端必须钝，以避免在取出横向主动脉时损坏它。</li>
	<li>快速但轻轻地拆下垫片，然后切开缝合线的末端。</li>
	<li>使用 5–0 尼龙缝合线关闭第一个间歇空间和皮肤。用75%的酒精再次消毒皮肤。</li>
	<li>将鼠标放在加热垫上，以促进恢复。手术后头3天静脉注射丁丙诺啡（0.1毫克/千克，q12h）。</li>
	<li>当老鼠恢复知觉时，将鼠标放回笼子，在12小时光/暗循环室中。</li>
	<li>执行与上述所有步骤相同的虚假手术，但没有收缩（步骤 3.5）。</li>
	<li>为丝绸缝合组执行手术，与上述所有步骤相同，但在第 1.2 步使用 5–0 丝缝合。</li>
</ol>4. 成功配对和测量的回声心电图评估
<ol><li>手术后在日（D）7进行心电图评估。</li>
	<li>麻醉小鼠3%通过吸入吸入感应，1.5%保持麻醉深度，0.5+1 L/分钟氧气流速。</li>
	<li>将鼠标置于平台上的超平位置，保持在 37 °C，并将四肢贴在电极上。</li>
	<li>用脱毛霜去除胸毛，在鼠标的胸部涂抹超声波耦合剂。</li>
	<li>使用 30 MHz 探头评估横向主动脉收缩。<ol>
<li>将平台向最左边倾斜。将探针保持垂直位置，并沿着右侧栏杆线将其放在胸部。然后，在 B 模式下操纵 X 轴和 Y 轴，直到主动脉拱门清晰可见。</li>
		<li>通过B模式定位收缩以获得主动脉拱视图11。使用彩色多普勒模式和脉冲波测量峰值流速，并选择速度超过 3，000 mm/s 的小鼠作为 TAC 组（值基于初步实验）。</li>
		<li>根据伯努利方程11的修改版本计算压力梯度: 压力梯度 =4 x V最大2。 注:横向主动脉收缩模型的理想压力梯度范围为40-80 mmHg11。</li>
		<li>使用 Cine 商店和帧存储保存数据和图像。</li>
	</ol>
</li>
	<li>使用 30 MHz 探头评估左心室 （LV） 的尺寸和收缩度。<ol>
<li>将平台重置为水平位置。相对于左侧的抛物线，将探头保持在 30° 逆时针。</li>
		<li>使用 B 模式并操纵 X 和 Y 以获得清晰而完整的心轴视图。</li>
		<li>按 M 模式显示指示线。使用 Cine 商店和框架存储获取图像，以以后测量 LV 腔室尺寸、部分缩短和 LV 壁厚度。</li>
	</ol>
</li>
	<li>一旦完成，停止异氟烷吸入，让小鼠从麻醉中恢复过来。然后，将动物送回笼子，在12小时光/暗循环室。</li>
	<li>在手术后的D14和D28上，重复上述步骤测量心脏参数，然后收获心脏进行组虫学研究。</li>
</ol>

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作者没有什么可透露的。

在心脏非缺血预科中，仍然存在着一个大大不足的区域。根据我们以前的研究，我们改用可吸收的缝合线来改善心肌肥大预后模式。
在先前的报告中，许多调查人员使用丝绸缝合来收缩主动脉拱门8号、14号、15号。丝绸缝合很容易获得，经常用于手术伤口缝合，组织结块和组织固定。在此协议中，我们用?...

缺血性先导是一种现象，诱发短暂的非致命性缺血发作和对心脏的再灌注，并有能力显著减少心肌损伤1。鉴于缺血性先决条件的明显临床意义，如限制心肌梗塞大小2和抑制心室心肌梗塞后心肌复明3，已经有很多研究来解剖机制潜在的心防作用诱导的先决条件4，5。相比之下，其他非缺血的先决条件却很少受到关注。心脏肥大可能钝化在主动脉狭窄患者进行主动脉瓣更换6。在存在病理心肌萎缩状态的地方，很少报告先决条件原理。
1991年，罗克曼等人首次建立了通过横向主动脉收缩（TAC）7导致左心室肥大的小鼠模型。通过在小鼠中两次操作TAC，我们先前已经证明心肌肥大预后（MHP）会导致心脏短暂性肥大刺激，从而使心脏在未来8月对持续的肥大压力更具抵抗力。MHP模型的特点已通过超声波生物显微镜和血动力学评估9得到验证。构建模型的要点是执行胸腔切除术三次，TAC 一周，解散一周，二级 TAC 6 周。然而，去组织可能导致出血，这使得新手难以掌握，也难以推广。此外，给小鼠进行管网也是一项技术挑战。不当的受管可能导致气管损伤、肺气管损伤，甚至导致小鼠死亡。因此，在构建MHP模型的同时，改进一些程序是必要和有价值的。
为了降低模型的难度并增加其成功率，我们切换到可吸收的缝合线为第一个TAC，并通过测量压力梯度通过回声心动图10下主动脉收缩监测模型的成功。根据我们的初步实验，在压力梯度过低的小鼠中很难诱发足够的心肌肥大，而压力梯度过高的小鼠会发展成急性心力衰竭甚至死亡。模型的理想压力梯度范围为 40–80 mmHg11。此外，这个实验没有依靠呼吸机，它可以有效地避免呼吸机相关的技术操作和伤害12。

<table>
	<tbody>
		<tr>
			<td>Absorbable suture (5-0)</td>
			<td>Shandong Kang Lida Medical Products Co., Ltd</td>
			<td>5-0</td>
			<td>Ligation</td>
		</tr>
		<tr>
			<td>Animal ultrasound system VEVO2100</td>
			<td>Visual Sonic</td>
			<td>VEVO2100</td>
			<td>Echocardiography</td>
		</tr>
		<tr>
			<td>Cold light illuminator</td>
			<td>Olympus</td>
			<td>ILD-2</td>
			<td>Light</td>
		</tr>
		<tr>
			<td>Heat pad- thermostatic surgical system (ALC-HTP-S1)</td>
			<td>SHANGHAI ALCOTT BIOTECH CO</td>
			<td>ALC-HTP-S1</td>
			<td>Heating</td>
		</tr>
		<tr>
			<td>Isoflurane</td>
			<td>RWD life science</td>
			<td>R510-22</td>
			<td>Inhalant anaesthesia</td>
		</tr>
		<tr>
			<td>Matrx VIP 3000 Isofurane Vaporizer</td>
			<td>Midmark Corporation</td>
			<td>VIP 3000</td>
			<td>Anesthetization</td>
		</tr>
		<tr>
			<td>Medical nylon suture (5-0)</td>
			<td>Ningbo Medical Needle Co.</td>
			<td>5-0</td>
			<td>Close the skin</td>
		</tr>
		<tr>
			<td>Pentobarbital sodium salt</td>
			<td>Merck</td>
			<td>25MG</td>
			<td>Anesthetization</td>
		</tr>
		<tr>
			<td>Precision electronic balance</td>
			<td>Denver Instrument</td>
			<td>TB-114</td>
			<td>Weighing sensor</td>
		</tr>
		<tr>
			<td>Self-made spacer</td>
			<td></td>
			<td></td>
			<td>25-gauge needle</td>
		</tr>
		<tr>
			<td>Silk suture (5-0)</td>
			<td>Yangzhou Yuankang Medical Devices Co., Ltd.</td>
			<td>5-0</td>
			<td>Ligation</td>
		</tr>
		<tr>
			<td>Small animal microsurgery equipment</td>
			<td>Napox</td>
			<td>MA-65</td>
			<td>Surgical instruments</td>
		</tr>
		<tr>
			<td>Transmission Gel</td>
			<td>Guang Gong pai</td>
			<td>250ML</td>
			<td>Echocardiography</td>
		</tr>
		<tr>
			<td>Veet hair removal cream</td>
			<td>Reckitt Benchiser</td>
			<td>RQ/B 33 Type 2</td>
			<td>Remove hair of mice</td>
		</tr>
		<tr>
			<td>Vertical automatic electrothermal pressure steam sterilizer</td>
			<td>Hefei Huatai Medical Equipment Co.</td>
			<td>LX-B50L</td>
			<td>Auto clean the surgical instruments</td>
		</tr>
	</tbody>
</table>

operating transverse aortic constriction with absorbable suture to obtain transient myocardial hypertrophy

基于小鼠两次横向主动脉收缩（TACs），证明心肌肥大预后（MHP）可以减轻心肌细胞肥大，减缓心力衰竭的进展。然而，对于新手来说，MHP模型通常很难建立，因为呼吸机操作的技术障碍，反复打开胸部，以及脱体引起的出血。为了促进这种模式，提高手术成功率和减少出血的发生率，我们改用可吸收的缝合线进行第一次TAC梳理，采用无呼吸机技术。使用2周的可吸收缝合，我们证明这个程序可能会导致严重的心肌萎缩在2周:手术后4周，心肌萎缩几乎完全退回到基线。使用此协议，操作员可以轻松掌握 MHP 模型，降低操作死亡率。

在这项研究中，我们随机将45只小鼠分成三组，分别是假象组、丝缝组和可吸收缝合组（TAC之后D0（基线）、D14和D28上每组的数量分别为15、10和5）。手术后的D7、D14、D21和D28，收缩的峰值速度由心电图确定。我们发现，在TAC之后的第二周，收缩处的血流速度仍然大于3，000毫米/秒，即使使用可吸收的缝合线收缩主动脉拱门（图1A）。此外，可吸收缝合组收缩时的压力梯度在2周...

Watch this Scientific Journal Video about Operating Transverse Aortic Constriction with Absorbable Suture to Obtain Transient Myocardial Hypertrophy at JoVE.com

Operating Transverse Aortic Constriction with Absorbable Suture to Obtain Transient Myocardial Hypertrophy

该协议提出了一个改进的方法，以获得可吸收的缝合的瞬时心肌肥大，模拟左心室肥大减少后，消除压力过载。它可能对心肌肥大先天性研究很有价值。

操作横向主动脉收缩与可吸收的缝合获得瞬时心肌萎缩

Based on twice transverse aortic constrictions (TACs) in mice, it is proved that myocardial hypertrophic preconditioning (MHP) could attenuate ...

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Medicine

6.2K 次观看.  Southern Medical University. 该协议提出了一个改进的方法，以获得可吸收的缝合的瞬时心肌肥大，模拟左心室肥大减少后，消除压力过载。它可能对心肌肥大先天性研究很有价值。

视频: Operating Transverse Aortic Constriction with Absorbable Suture to Obtain Transient Myocardial Hypertrophy

A Research Method For Detecting Transient Myocardial Ischemia In Patients With Suspected Acute Coronary Syndrome Using Continuous ST-segment Analysis

Each year, an estimated 785,000 Americans will have a new coronary attack, or acute coronary syndrome (ACS). The pathophysiology of ACS involves rupture of an atherosclerotic plaque; hence, treatment is aimed at plaque stabilization in order to prevent cellular death. However, there is considerable debate among clinicians, about which treatment pathway is best: early invasive using percutaneous coronary intervention (PCI/stent) when indicated or a conservative approach (i.e., medication only with PCI/stent if recurrent symptoms occur).
There are three types of ACS: ST elevation myocardial infarction (STEMI), non-ST elevation MI (NSTEMI), and unstable angina (UA). Among the three types, NSTEMI/UA is nearly four times as common as STEMI. Treatment decisions for NSTEMI/UA are based largely on symptoms and resting or exercise electrocardiograms (ECG). However, because of the dynamic and unpredictable nature of the atherosclerotic plaque, these methods often under detect myocardial ischemia because symptoms are unreliable, and/or continuous ECG monitoring was not utilized.
Continuous 12-lead ECG monitoring, which is both inexpensive and non-invasive, can identify transient episodes of myocardial ischemia, a precursor to MI, even when asymptomatic. However, continuous 12-lead ECG monitoring is not usual hospital practice; rather, only two leads are typically monitored. Information obtained with 12-lead ECG monitoring might provide useful information for deciding the best ACS treatment.
Purpose. Therefore, using 12-lead ECG monitoring, the COMPARE Study (electroCardiographic evaluatiOn of ischeMia comParing invAsive to phaRmacological trEatment) was designed to assess the frequency and clinical consequences of transient myocardial ischemia, in patients with NSTEMI/UA treated with either early invasive PCI/stent or those managed conservatively (medications or PCI/stent following recurrent symptoms). The purpose of this manuscript is to describe the methodology used in the COMPARE Study.
Method. Permission to proceed with this study was obtained from the Institutional Review Board of the hospital and the university. Research nurses identify hospitalized patients from the emergency department and telemetry unit with suspected ACS. Once consented, a 12-lead ECG Holter monitor is applied, and remains in place during the patient's entire hospital stay. Patients are also maintained on the routine bedside ECG monitoring system per hospital protocol. Off-line ECG analysis is done using sophisticated software and careful human oversight.

Continuous 12-lead electrocardiographic (ECG) monitoring can identify transient myocardial ischemia, even when asymptomatic, among patients with suspected acute coronary syndrome (ACS). In this article we describe our method for initiating patient monitoring using a Holter device, downloading the ECG data for off-line analysis, and how to utilize the ECG software to identify transient ischemia.

研究方法检测疑似急性冠脉综合征患者短暂心肌缺血的连续ST段分析

Each year, an estimated 785,000 Americans will have a new coronary attack, or acute coronary syndrome (ACS). The pathophysiology of ACS involves rupture ...

科研

医学

Ascending Aortic Constriction in Rats for Creation of Pressure Overload Cardiac Hypertrophy Model

Ascending aortic constriction is the most common and successful surgical model for creating pressure overload induced cardiac hypertrophy and heart failure. Here, we describe a detailed surgical procedure for creating pressure overload and cardiac hypertrophy in rats by constriction of the ascending aorta using a small metallic clip. After anesthesia, the trachea is intubated by inserting a cannula through a half way incision made between two cartilage rings of trachea. Then a skin incision is made at the level of the second intercostal space on the left chest wall and muscle layers are cleared to locate the ascending portion of aorta. The ascending aorta is constricted to 50&#8211;60% of its original diameter by application of a small sized titanium clip. Following aortic constriction, the second and third ribs are approximated with prolene sutures. The tracheal cannula is removed once spontaneous breathing was re-established. The animal is allowed to recover on the heating pad by gradually lowering anesthesia. The intensity of pressure overload created by constriction of the ascending aorta is determined by recording the pressure gradient using trans-thoracic two dimensional Doppler-echocardiography. Overall this protocol is useful to study the remodeling events and contractile properties of the heart during the gradual onset and progression from compensated cardiac hypertrophy to heart failure stage.

We describe a stepwise procedure for creating pressure overload and left ventricular hypertrophy in Wistar rats by constriction of the ascending aorta using a small metallic clip. This model is extensively used for studying remodeling changes during cardiac hypertrophy and for identifying and evaluating strategies for regression of such changes.

大鼠建立压力超负荷心肌肥厚模型在升主动脉缩窄

Ascending aortic constriction is the most common and successful surgical model for creating pressure overload induced cardiac hypertrophy and heart ...

Murine Isolated Heart Model of Myocardial Stunning Associated with Cardioplegic Arrest

The following protocol is of use to evaluate impaired cardiac function or myocardial stunning following moderate ischemic insults. The technique is useful for modeling ischemic injury associated with numerous clinically relevant phenomenon including cardiac surgery with cardioplegic arrest and cardiopulmonary bypass, off-pump CABG, transplant, angina, brief ischemia, etc. The protocol presents a general method to model hypothermic hyperkalemic cardioplegic arrest and reperfusion in rodent hearts focusing on measurement of myocardial contractile function. In brief, a mouse heart is perfused in langendorff mode, instrumented with an intraventricular balloon, and baseline cardiac functional parameters are recorded. Following stabilization, the heart is then subject to brief infusion of a cardioprotective hypothermic cardioplegia solution to initiate diastolic arrest. Cardioplegia is delivered intermittently over 2 hr. The heart is then reperfused and warmed to normothermic temperatures and recovery of myocardial function is monitored. Use of this protocol results in reliable depressed cardiac contractile function free from gross myocardial tissue damage in rodents.

The goal of this protocol to assess myocardial stunning following ischemic cardioplegic arrest in rodents.

心肌顿抑相关的小鼠离体心脏模型心脏停搏

The following protocol is of use to evaluate impaired cardiac function or myocardial stunning following moderate ischemic insults. The technique is useful ...

Assessment of Cardiac Morphological and Functional Changes in Mouse Model of Transverse Aortic Constriction by Echocardiographic Imaging

Transverse aortic constriction (TAC) in mice has been used as a valuable model to study mechanisms of cardiac hypertrophy and heart failure1. A reliable noninvasive method is essential to assess real-time cardiac morphological and functional changes in animal models of heart disease. Transthoracic echocardiography represents an important tool for noninvasive assessment of cardiac structure and function2. Here we used a high-resolution ultrasound imaging system to monitor myocardial remodeling and heart failure progression over time in a mouse model of TAC. B-mode, M-mode, and Doppler imaging were used to precisely assess cardiac hypertrophy, ventricular dilatation, and functional deterioration in mice following TAC. Color and pulse wave (PW) Doppler imaging was used to noninvasively measure pressure gradient across the aortic constriction created by TAC and to assess transmitral blood flow in mice. Thus transthoracic echocardiographic imaging provides comprehensive noninvasive measurements of cardiac dimensions and function in mouse models of heart disease.

The goal of this protocol is to noninvasively assess cardiac structural and functional changes in a mouse model of heart disease created by transverse aortic constriction, using B- and M-mode echocardiography and color/pulse wave Doppler imaging.

在横向主动脉缩窄的小鼠模型和心脏形态学评估功能改变通过超声心动图成像

Transverse aortic constriction (TAC) in mice has been used as a valuable model to study mechanisms of cardiac hypertrophy and heart failure1. A reliable ...

Minimally Invasive Transverse Aortic Constriction in Mice

Minimally invasive transverse aortic constriction (MTAC) is a more desirable method for the constriction of the transverse aorta in mice than standard open-chest transverse aortic constriction (TAC). Although transverse aortic constriction is a highly functional method for the induction of high pressure in the left ventricle, it is a more difficult and lengthy procedure due to its use of artificial ventilation with tracheal intubation. TAC is oftentimes also less survivable, as the newer method, MTAC, neither requires the cutting of the ribs and intercostal muscles nor tracheal intubation with a ventilation setup. In MTAC, as opposed to a thoracotomy to access to the chest cavity, the aortic arch is reached through a midline incision in the anterior neck. The thyroid is pulled back to reveal the sternal notch. The sternum is subsequently cut down to the second rib level, and the aortic arch is reached simply by separating the connective tissues and thymus. From there, a suture can be wrapped around the arch and tied with a spacer, and then the sternal cut and skin can be closed. MTAC is a much faster and less invasive way to induce left ventricular hypertension and enables the possibility for high-throughput studies. The success of the constriction can be verified using high-frequency trans-thoracic echocardiography, particularly color Doppler and pulsed-wave Doppler, to determine the flow velocities of the aortic arch and left and right carotid arteries, the dimension of the blood vessels, and the left ventricular function and morphology. A successful constriction will also trigger significant histopathological changes, such as cardiac muscle cell hypertrophy with interstitial and perivascular fibrosis. Here, the procedure of MTAC is described, demonstrating how the resulting flow changes in the carotid arteries can be examined with echocardiography, gross morphology, and histopathological changes in the heart.

Minimally invasive transverse aortic constriction (MTAC) conserves the essentials of regular transverse aortic constriction (TAC) while eliminating the use of a ventilator with tracheal intubation. It proves to be a highly desirable method for high-throughput studies on left ventricular overload, particularly in translational studies.

微创横向主动脉缩窄小鼠

Minimally invasive transverse aortic constriction (MTAC) is a more desirable method for the constriction of the transverse aorta in mice than standard ...

Full-root Aortic Valve Replacement by Stentless Aortic Xenografts in Patients with Small Aortic Roots

In patients with small aortic roots who need an aortic valve replacement with biological valve substitutes, the implantation of the stented pericardial valve might not meet the functional needs. The implantation of a too-small stented pericardial valve, leading to an effective orifice area indexed to a body surface area less than 0.85 cm2/m2, is regarded as prosthesis-patient mismatch (PPM). A PPM negatively affects the regression of left ventricular hypertrophy and thus the normalization of left ventricular function and the alleviation of symptoms. Persistent left ventricular hypertrophy is associated with an increased risk of arrhythmias and sudden cardiac death. In the case of predictable PPM, there are three options: 1) accept the PPM resulting from the implantation of a stented pericardial valve when comorbidities of the patient forbid the more technically demanding operative technique of implanting a larger prosthesis, 2) enlarge the aortic root to accommodate a larger stented valve substitute, or 3) implant a stentless biological valve or a homograft. Compared to classical aortic valve replacement with stented pericardial valves, the full-root implantation of stentless aortic xenografts offers the possibility of implanting a 3-4 mm larger valve in a given patient, thus allowing significant reduction in transvalvular gradients. However, a number of cardiac surgeons are reluctant to transform a classical aortic valve replacement with stented pericardial valves into the more technically challenging full-root implantation of stentless aortic xenografts. Given the potential hemodynamic advantages of stentless aortic xenografts, we have adopted full-root implantation to avoid PPM in patients with small aortic roots necessitating an aortic valve replacement. Here, we describe in detail a technique for the full-root implantation of stentless aortic xenografts, with emphasis on the management of the proximal suture line and coronary anastomoses. Limitations of this technique and alternative options are discussed.

Full-root aortic valve replacement by stentless aortic xenograft is a viable option in patients with small aortic roots. We describe, a technique for the full-root implantation of stentless aortic xenografts, with emphasis on the management of the proximal suture line and coronary anastomoses, and discuss its limitations and alternative options.

全根主动脉瓣置换主动脉瓣狭窄主动脉异种移植患者小主动脉根

In patients with small aortic roots who need an aortic valve replacement with biological valve substitutes, the implantation of the stented pericardial ...

Technique of Minimally Invasive Transverse Aortic Constriction in Mice for Induction of Left Ventricular Hypertrophy

Transverse aortic constriction (TAC) in mice is one of the most commonly used surgical techniques for experimental investigation of pressure overload-induced left ventricular hypertrophy (LVH) and its progression to heart failure. In the majority of the reported investigations, this procedure is performed with intubation and ventilation of the animal which renders it demanding and time-consuming and adds to the surgical burden to the animal. The aim of this protocol is to describe a simplified technique of minimally invasive TAC without intubation and ventilation of mice. Critical steps of the technique are emphasized in order to achieve low mortality and high efficiency in inducing LVH.
Male C57BL/6 mice (10-week-old, 25-30 g, n=60) were anesthetized with a single intraperitoneal injection of a mixture of ketamine and xylazine. In a spontaneously breathing animal following a 3-4 mm upper partial sternotomy, a segment of 6/0 silk suture threaded through the eye of a ligation aid was passed under the aortic arch and tied over a blunted 27-gauge needle. Sham-operated animals underwent the same surgical preparation but without aortic constriction. The efficacy of the procedure in inducing LVH is attested by a significant increase in the heart/body weight ratio. This ratio is obtained at days 3, 7, 14 and 28 after surgery (n = 6 - 10 in each group and each time point). Using our technique, LVH is observed in TAC compared to sham animals from day 7 through day 28. Operative and late (over 28 days) mortalities are both very low at 1.7%.
In conclusion, our cost-effective technique of minimally invasive TAC in mice carries very low operative and post-operative mortalities and is highly efficient in inducing LVH. It simplifies the operative procedure and reduces the strain put on the animal. It can be easily performed by following the critical steps described in this protocol.

The aim of this protocol is to describe step-by-step the technique of minimally invasive transverse aortic constriction (TAC) in mice. By elimination of intubation and ventilation which are mandatory for the commonly used standard procedure, minimally invasive TAC simplifies the operative procedure and reduces the strain put on the animal.

小鼠横主动脉狭窄诱导左心室肥厚的技术研究

Transverse aortic constriction (TAC) in mice is one of the most commonly used surgical techniques for experimental investigation of pressure ...

A Closed-chest Model to Induce Transverse Aortic Constriction in Mice

Research on cardiac hypertrophy and heart failure is frequently based on pressure overload mouse models induced by TAC. The standard procedure is to perform a partial thoracotomy to visualize the transverse aortic arch. However, the surgical trauma caused by the thoracotomy in open-chest models changes the respiratory physiology as the ribs are dissected and left unattached after chest closure. To prevent this, we established a minimally invasive, closed chest approach via lateral thoracotomy. Herein we approach the aortic arch via the 2nd intercostal space without entering the chest cavities, leaving the mouse with a less traumatic injury to recover from. We perform this operation using standard laboratory settings for open chest TAC procedures with equal survival rates. Apart from maintaining physiological breathing patterns due to the closed chest approach, the mice seem to benefit by showing rapid recovery, as the less invasive technique appears to facilitate a fast healing process and to reduce immune response after trauma.

Here, we present a protocol of Transverse Aortic constriction (TAC) via a lateral thoracotomy. This technique is a minimally invasive, closed chest surgical procedure aiming to simulate pressure overload and heart failure in mice utilizing standard TAC laboratory settings.

诱导小鼠横向主动脉狭窄的闭合胸模型

Research on cardiac hypertrophy and heart failure is frequently based on pressure overload mouse models induced by TAC. The standard procedure is to ...

Laparoscopic Repair of Para-Esophageal Hernia Using Absorbable Biosynthetic Mesh

Para-esophageal hernia repairs are challenging procedures and there is no consensus on the optimal approach to repair. Mesh reinforcement has been associated with lesser hernia recurrence when compared to the primary suture repair. The type of mesh that is most appropriate is still debatable. Synthetic and biosynthetic materials have been studied in the literature. It is well documented that a synthetic mesh is associated with esophageal erosion and migration into the stomach. Though there are limited long-term data on biosynthetic mesh, the short-term results are excellent and promising.
This paper illustrates how a biosynthetic prosthesis can be safely used with fibrin glue fixation and anterior Dor fundoplication to repair any para-esophageal defect. The absorbable biosynthetic mesh has been shown to produce good long-term patient satisfaction outcomes and low recurrence rates compared to conventional methods including repair with synthetic mesh. This technique also avoids the risk of esophageal erosion whilst strengthening the repair. Tacks that are still widely used to secure the mesh can be abandoned due to the associated risk of developing cardiac tamponade, or other disastrous consequences. This repair method, also, highlights how the prosthesis can be fashioned into a V-shape and easily placed in an onlay fashion behind the esophagus. The protocol demonstrates an alternative and safer method for mesh fixation using fibrin glue.

Presented here is a protocol of para-esophageal hernia repair. Use of absorbable biosynthetic mesh avoids the risk of erosion through the esophagus whilst reinforcing the repair. Glue fixation is preferred to avoid the risk of trauma such as bleeding or cardiac tamponade, which are associated with stitches or tacks.

使用可吸收的生物合成网格对副食管气喘进行拉帕罗镜修复

Para-esophageal hernia repairs are challenging procedures and there is no consensus on the optimal approach to repair. Mesh reinforcement has been ...

Murine Cervical Aortic Transplantation Model using a Modified Non-Suture Cuff Technique

With the introduction of powerful immunosuppressive protocols, distinct advances are possible in the prevention and therapy of acute rejection episodes. However, only minor improvement in the long-term results of transplanted solid organs could be observed over the past decades. In this context, chronic allograft vasculopathy (CAV) still represents the leading cause of late organ failure in cardiac, renal and pulmonary transplantation.
Thus far, the underlying pathogenesis of CAV development remains unclear, explaining why effective treatment strategies are presently missing and emphasizing a need for relevant experimental models in order to study the underlying pathophysiology leading to CAV formation. The following protocol describes a murine heterotopic cervical aortic transplantation model using a modified non-suture cuff technique. In this technique, a segment of the thoracic aorta is interpositioned in the right common carotid artery. With the use of the non-suture cuff technique, an easy to learn and reproducible model can be established, minimizing the possible heterogeneity of sutured vascular micro anastomoses.

Here, we present a protocol of heterotopic aortic transplantation in mice using the non-suture cuff technique in a cervical murine model. This model can be used to study the underlying pathology of chronic allograft vasculopathy (CAV) and can help evaluate new therapeutic agents in order to prevent its formation.

使用改性非缝合铐技术的宫颈主动脉移植模型

With the introduction of powerful immunosuppressive protocols, distinct advances are possible in the prevention and therapy of acute rejection episodes. ...