이 작품은 중국 국립 자연과학 재단(81770271; Y, 랴오)의 보조금, 중국 국립자연과학재단 공동기금(U1908205; Y, 랴오)의 공동기금, 광저우 과학기술 도시계획프로젝트(201804020083; 리아오 박사)의 보조금으로 지원되었다.

모든 절차는 미국 국립 보건원 (NIH 간행물 번호 85-23, 1996년에 개정됨)에 의해 간행된 실험실 동물의 배려 그리고 사용의 지침에 따라 행해졌습니다. C57BL/6J 남성 마우스(8-10주, 20-25g)는 사우스 의과대학의 동물 센터에서 제공하였다.
1. 수술 전 준비
<ol><li>바늘 홀더와 25 G 바늘의 끝을 꼬집어 홀더와 같은 단단한 물체로 무딘.</li>
	<li>바늘을 통해 5-0 흡수 봉합사를 통과한 다음 홀더13로90°로 곡선을 이드합니다. 참고: 다른 연구 목적에 따르면, 조사자 다른 흡수 시간으로 흡수 성 라인을 선택할 수 있습니다. 이 프로토콜에서는 대동맥 아치를 수축시키기 위해 2주 동안 흡수 가능한 봉합사를 사용했습니다.</li>
	<li>또 다른 25 G 바늘을 120°로 구부리고 결찰 단계에서 스페이서로 사용할 홀더로 팁을 부드럽게 합니다. 참고: 25 G 바늘은 체중(BW) >25g을 갖는 마우스를 위한 스페이서로 사용되었다. 19-24 g BW를 가진 마우스를 위해 26 G 바늘을 사용하십시오.</li>
	<li>75 %의 알코올로 수술 부위를 소독하십시오.</li>
	<li>가열 패드 온도를 37 °C로 조정합니다.</li>
	<li>멸균 수술 기구(안과 가위 1개, 마이크로 가위 1개, 미세 수술 팔꿈치 핀셋 2개, 바늘 홀더 1개, 마이크로 바늘 홀더 1개 포함)를 준비합니다.</li>
</ol>2. 마취및 면도의 유도
<ol><li>식염수 용액(0.9% NaCl)에서 희석된 자일라진(5 mg/kg)과 케타민(100 mg/kg)의 혼합물을 관성 주사로 마우스를 마취한다. 네거티브 페달 철수 반사로 완전한 마취를 확인합니다.</li>
	<li>봉합사로 절개를 고정하고 접착 테이프로 팔다리를 고정하여 마우스를 supine 위치에 두십시오.</li>
	<li>목과 xiphoid에 머리카락을 제거하기 위해 탈모 크림을 바르습니다. 요오드로 지역을 소독한 다음 75%의 알코올을 제거합니다.</li>
</ol>3. 수술
<ol><li>슈프라 흉골 노치와 메스가 있는 가슴 사이의 중간 위치에서 10mm 이상의 절개를 합니다. 그런 다음 피부와 피상적 인 근막을 분리합니다.</li>
	<li>흉부 각도에서 갈비뼈를 세어 첫 번째 늑간 공간을 식별합니다. 첫 번째 늑간 공간에서 절개를 수행하고 흉골에 가능한 한 가깝게 수행하십시오. 이 공간을 열기 위해 팔꿈치 핀셋으로 무뚝뚝하게 침투합니다.</li>
	<li>횡방향 대동맥 아치가 보일 때까지 완두엽과 흉막을 부드럽게 분리합니다. 참고: 폐렴을 피하기 위해 정수리 흉막을 손상시키지 마십시오.</li>
	<li>brachiocephalic 동맥과 래치 바늘(14)으로좌측 일반적인 경동맥 사이의 대동맥 아치 아래 5-0 흡수 봉합사를 통과한다. 브라치오페할릭 동맥, 왼쪽 공통 경동맥 및 왼쪽 아파르비아 동맥이 수술 장에서 볼 수 있는지 확인하십시오.</li>
	<li>1.3단계에서 준비된 스페이서를 횡방향 대오르타에 놓고 3.4단계에서 봉합사를 가진 스페이서에 이중 매듭을 수행한다. 참고: 스페이서의 끝은 비뚤어져야 제거하면서 횡방향 대어를 손상시키지 않도록 무디어야 합니다.</li>
	<li>스페이서를 빠르고 부드럽게 제거한 다음 봉합사의 끝을 잘라냅니다.</li>
	<li>5-0 나일론 봉합사를 사용하여 첫 번째 늑간 공간과 피부를 닫습니다. 75%의 알코올로 피부를 다시 소독합니다.</li>
	<li>복구를 촉진하기 위해 가열 패드에 마우스를 배치합니다. 수술 후 첫 3일 동안 부프레노르핀(0.1 mg/kg, q12h)을 인트라피톤으로 주입합니다.</li>
	<li>의식을 회복할 때 12h 의 빛/어두운 사이클 룸에서 마우스를 케이지로 되돌려 놓습니다.</li>
	<li>위의 모든 단계와 동일한 가짜 수술을 수행하지만 수축없이 (단계 3.5).</li>
	<li>위의 모든 단계와 동일하지만 1.2 단계에서 5-0 실크 봉합사를 사용하여 실크 봉합사 그룹에 대한 수술을 수행합니다.</li>
</ol>4. 성공적인 결찰 및 측정에 대한 심초음파 평가
<ol><li>수술 후 7일(D) 심초음파 평가를 실시합니다.</li>
	<li>흡입을 위한 흡입을 통해 3% 이소플루란으로 마우스를 마취하고, 마취의 깊이를 유지하기 위한 1.5%,산소 유량은 0.5-1L/min로 마우스를 마취한다.</li>
	<li>37°C에서 유지된 마우스를 플랫폼에 스핀 위치에 놓고 팔다리를 전극에 테이프로 놓습니다.</li>
	<li>분모 크림으로 가슴 머리를 제거하고 마우스의 가슴에 초음파 커플링 제를 적용합니다.</li>
	<li>30MHz 프로브를 통해 횡방향 대동맥 수축을 평가합니다.<ol>
<li>플랫폼을 맨 왼쪽으로 기울이게 합니다. 프로브를 수직 위치에 두고 오른쪽 파라스테랄 라인을 따라 가슴에 낮춥습니다. 그런 다음 대동맥 아치가 명확하게 표시될 때까지 B 모드에서 X축 및 Y축을 조작합니다.</li>
		<li>대동맥 아치뷰(11)를얻기 위해 B 모드로 수축을 찾습니다. 색상 도플러 모드와 펄스 웨이브를 사용하여 피크 유량 속도를 측정하고 TAC 그룹으로 3,000mm/s 이상의 속도를 가진 마우스를 선택합니다(값은 예비 실험을 기반으로 합니다).</li>
		<li>베르누이 의 방정식11의수정 된 버전에 따라 압력 그라데이션을 계산합니다 . 압력 그라데이션 = 4 x V최대2. 참고: 횡방향 대동맥 수축 모델에 대한 이상적인 압력 그라데이션은 40-80 mmHg11범위입니다.</li>
		<li>Cine 스토어 및 프레임 스토어를 사용하여 데이터와 이미지를 저장합니다.</li>
	</ol>
</li>
	<li>30MHz 프로브를 통해 왼쪽 심실(LV)의 치수와 수축도 평가합니다.<ol>
<li>플랫폼을 수평 위치로 재설정합니다. 프로브를 왼쪽 파라스테랄 라인을 기준으로 시계 반대 방향으로 30° 유지합니다.</li>
		<li>B 모드를 사용하여 X와 Y를 조작하여 심장의 명확하고 전체 긴 축 보기를 얻습니다.</li>
		<li>M 모드를 눌러 표시선을 표시합니다. Cine Store 및 프레임 스토어를 통해 이미지를 획득하여 LV 챔버 치수, 분수 단축 및 LV 벽 두께를 나중에 측정합니다.</li>
	</ol>
</li>
	<li>완료되면 이소플루란 흡입을 멈추고 마우스가 마취에서 회복되도록 하십시오. 그런 다음 12h 의 빛 / 어두운 사이클 룸에서 동물을 케이지로 돌려 놓습니다.</li>
	<li>수술 후 D14 및 D28에서 위의 단계를 반복하여 심장 매개 변수를 측정한 다음 조직학 연구를 위해 심장을 수확합니다.</li>
</ol>

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저자는 공개 할 것이 없습니다.

심장 비 허혈성 사전 조절에 여전히 크게 미개척 지역이 있다. 이전 연구에 따르면, 우리는 심근 비대 성 사전 조절 모델을 개선하기 위해 흡수 가능한 봉합사를 사용하여 전환했습니다.
이전 보고서에서 많은 조사관이 실크 봉합사를 사용하여 대동맥 아치8,14,15를수축시했습니다. 실크 봉합사는 쉽게 사용...

허혈성 사전 조절은 허혈과 재관류의 짧은 비치명적인 에피소드를 심장에 유도하고 심근 손상을 극적으로 감소시킬 수 있는 능력을 가진현상이다 1. 심근 경색 크기2제한 및 심근 방부 제3후 심실 타키야르 리듬을 억제하는 등 허혈성 사전 조절의 명백한 임상적 의미를 감안할 때,4,5에의해 유도된 유산소 보호 효과의 기전을 해부하기 위한 연구가 많이 있었다. 대조적으로, 사전 조절의 그밖 비 허혈성 모형은 상대적으로 작은 주의를 수신했습니다. 대동맥 판막 교체6을겪고 있는 대동맥 협착증 환자에서 심장 비대증이 무디게 될 수 있다. 병리학적 심근 비대의 상태가 존재하는 곳마다, 사전 조절의 원리는 거의 보고되지 않습니다.
1991년, Rockman 외. 먼저 횡방향 대동맥 수축(TAC)7에의해 좌심실 비대의 마우스 모델을 확립하였다. 마우스에서 TAC를 두 번 작동시킴으로써, 우리는 이전에 심근 대위 부전 (MHP)이 심장의 일시적인 비대성 자극으로 이어져 향후8에서지속적인 비대성 스트레스에 더 강한 심장을 만드는 것을 입증했습니다. MHP 모델의 특성은 초음파 생체 현미경 및 혈역학 평가9에의해 검증되었습니다. 모델을 구성하는 데 핵심사항은 소라코토미를 세 번, 일주일 동안 TAC, 일주일 동안 탈장, 6주 동안 보조 TAC를 수행하는 것이었습니다. 그러나, 탈대는 출혈을 일으킬 수 있습니다., 어렵게 초보자에 의해 마스터 하 고 대중화 하기 어려운. 또한 마우스를 삽관하는 기술적 과제이기도 합니다. 부적절한 삽관은 기관 손상, 기발성, 심지어 마우스의 사망을 일으킬 수 있습니다. 따라서 MHP 모델을 구성하는 동안 일부 절차를 개선하는 것이 필요하고 가치가 있습니다.
모델의 난이도를 줄이고 성공을 높이기 위해, 우리는 첫 번째 TAC에 대한 흡수 봉합사로 전환하고 에코카르디그래피10에서대동맥 수축을 가로 질러 압력 그라데이션을 측정하여 모델의 성공을 모니터링했습니다. 우리의 예비 실험에 근거하여, 너무 저압 그라데이션을 가진 마우스에 있는 충분한 심근 비대를 유도하는 것은 어려울 것입니다, 너무 고압 그라데이션을 가진 마우스는 급성 심부전또는 정지를 개발할 것입니다 동안. 모델에 이상적인 압력 그라데이션은 40-80 mmHg11범위입니다. 또한,이 실험은 인공 호흡기에 의존하지 않았으며, 이는 인공호흡기 관련 기술적 조작 및부상(12)을효과적으로 피할 수 있었다.

<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

마우스의 두 번 횡단 대동맥 수축 (TAC)에 기초하여, 심근 비대영양 (MHP)이 심근 세포 비대증을 감쇠하고 심부전으로진행을 늦출 수 있음을 입증된다. 그러나 초보자의 경우, MHP 모델은 일반적으로 인공호흡기 작동, 반복적으로 가슴을 열고 탈구로 인한 출혈로 인해 기술적 장애물로 인해 확립하기가 매우 어렵습니다. 이 모델을 용이하게하기 위해 수술 성공률을 높이고 출혈발생률을 줄이기 위해, 우리는 인공호흡기가 없는 기술로 첫 TAC 빗질을 위한 흡수성 봉합사로 전환했습니다. 2 주 흡수 봉합사를 사용 하 여, 우리는이 절차는 2 주에 중요 한 심근 비대를 일으킬 수 있습니다 입증; 그리고 수술 후 4 주, 심근 비대는 거의 완전히 기준선으로 회귀했다. 이 프로토콜을 사용하여 운영자는 낮은 작업 사망률로 MHP 모델을 쉽게 마스터할 수 있습니다.

본 연구에서는 45명의 마우스를 무작위로 3개 군, 샴, 실크 봉합사군 및 흡수가능한 봉합사군(TAC 후 D0(기준), D14 및 D28의 각 그룹의 수를 각각 15, 10 및 5로 나눕니다. D7, D14, D21 및 D28에서 수술 후 수축된 피크 속도는 에코카르디노그래피에 의해 결정되었다. 우리는 수축에서 혈류 속도가 여전히 3,000 mm /s보다 더 큰 것을 발견 TAC 후 두 번째 주에 흡수 봉합사가 대동맥 아치를 수축하는 데 사용되었음?...

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

이 프로토콜은 흡수 가능한 봉합사를 사용하여 일시적인 심근 비대증을 얻는 향상된 방법을 제시하며 압력 과부하를 제거 한 후 좌심실 비대 감소를 시뮬레이션합니다. 심근 대위 축 대 사전 조절에 대 한 연구에 대 한 가치가 있을 수 있습니다.

과도 심근 비대증을 얻기 위해 흡수 가능한 봉합사와 횡단 대동맥 수축 을 작동

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

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Research

JoVE Journal

Medicine

6.2K 조회수.  Southern Medical University. 이 프로토콜은 흡수 가능한 봉합사를 사용하여 일시적인 심근 비대증을 얻는 향상된 방법을 제시하며 압력 과부하를 제거 한 후 좌심실 비대 감소를 시뮬레이션합니다. 심근 대위 축 대 사전 조절에 대 한 연구에 대 한 가치가 있을 수 있습니다.

비디오: 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.

지속적인 ST 세그먼트 분석을 사용하여 의심되는 급성 관상 증후군 환자에서 심근 국소 빈혈 과도를 검출하기위한 연구 방법

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

연구

의학

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.

압력 과부하 심장 비대 모델의 창조를위한 쥐의 대동맥 수축 오름차순

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.

심정지 체포와 심근 놀라운 연합의 쥐 절연 심장 모델

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.

심 초음파 이미징에 의해 가로 대동맥 수축의 마우스 모델에서 심장 형태 학적 평가 및 기능 변경

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.

마우스의 최소 침습 가로 대동맥 수축

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.

작은 대동맥 근위 대동맥을 가진 환자에서 스텐트리스 대동맥 이식편을 이용한 대동맥 판막 치환술

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.

왼쪽된 심 실 비 대의 유도 대 한 생쥐에서 최소 침 습 가로 대동맥 수축의 기술

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.

마우스에 가로 대동맥 수축 유도를 폐쇄 가슴 모델

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

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.

수정된 비봉합사 커프 기술을 사용한 뮤린 자궁 경부 대동맥 이식 모델

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

Using Q Suture to Enhance Resistance to Gap Formation and Tensile Strength of Repaired Flexor Tendons

Peripheral epitendinous sutures are believed to enhance core suture strength in tendon repair and decrease the risk of gapping between tendon ends. Here Q suture, an alternative to peripheral sutures, is presented for the use in tendon repair. Its effects on gap formation and tensile strength of the repaired tendons were compared with conventional running peripheral sutures. Three 2-strand sutures and three 4-strand sutures were used in repairing porcine tendons. The time required for performing 2Q and running sutures were recorded. The repaired tendons were subjected to a cyclic loading test, and the cycle number, during which a 2-mm gap was formed, was determined. After the cyclic loading, the gap size at the tendon ends and the ultimate strength of the repaired tendons were measured. Augmentation with the Q sutures reduced the number of tendons showing 2-mm gaps at tendon ends during cyclic loading. With addition of Q sutures 2-strand sutures significantly increased the ultimate strength of the repaired tendons and 4-strand sutures decreased the gap distance at the repair site of tendons. The time required for performing 2Q sutures was significantly less than that for running sutures. Therefore, we conclude that the Q suture is efficient in enhancing the tensile resistance and tendon repair strength and can be an alternative to conventional peripheral sutures.

Here, we present a &#8220;Q&#8221; suture technique that can be performed in tendon repair and its effects on the gap formation and tensile strength of the repaired tendons. Q suture is shown to be efficient in enhancing the tensile resistance and tendon repair strength.

Q 봉합사를 사용하여 수리된 굴곡 텐돈의 갭 형성 및 인장 강도에 대한 저항력을 향상시킵니다.

Peripheral epitendinous sutures are believed to enhance core suture strength in tendon repair and decrease the risk of gapping between tendon ends. Here Q ...