Name: monitoring of systemic and hepatic hemodynamic parameters in mice
Uploaded: 2014-10-04T14:00:00
Description: Watch this Scientific Journal Video about Monitoring of Systemic and Hepatic Hemodynamic Parameters in Mice at JoVE.com

This research was supported by the German Federal Ministery for Education and Research (BMBF) funded &#8220;Virtual Liver Network&#8221;. I&#8217;d like to thank Frank Schubert and Rene Gumpert from the media center of Jena University Hospital for their help in producing the video and creating the animation and Isabel Jank for recording the audio.

Housing and all procedures carried out were in accordance with German Animal Welfare Legislation.
1. Sensors Calibration&#160;(Follow Manufacturer&#39;s Instructions for Sensors Calibration)
1.1) Millar catheter calibration. Pre-soak the tip of the catheter in sterile water or saline for 30 min prior to balance (zeroing) and calibration.
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	<li>Connect the millar sensor to the millar1 channel of bridge amplifier and insert the millar sensor tip into water column.<...

<ol>
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Biol. 25 (6), 725-731 (2001).</li><li>Cheever, A. W., Warren, K. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Portal+vein+ligation+in+mice:+portal+hypertension,+collateral+circulation,+and+blood+flow.">Portal vein ligation in mice: portal hypertension, collateral circulation, and blood flow.</a> 18, 405-407 (1963).</li><li>Costa, G., Aguiar, B. G., Coelho, P. M., Cunha-Melo, J. 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Monitoring of hepatic hemodynamics is an important research tool in hepatology and hepatobiliary surgery. Acquisition of hepatic hemodynamic data helps to characterize the effect of hepatobiliary procedures on the circulatory system. Acquisition of hepatic hemodynamic data is also needed to study the effect of drugs affecting portal pressure and portal flow, e.g., as needed in studies evaluating vasoactive drugs.
Despite the small size, the vital parameters, systemic and hepatic hemod...

The overall goal of this video was to demonstrate a real-time monitoring procedure for acquiring systemic and hepatic hemodynamic parameters. The rationale for developing this procedure is its great value for experimental interventions in mice&#160;that require&#160;obtaining systemic and hepatic hemodynamic parameters. The procedure can be applied to na&#239;ve animals and during or after a given hepato-biliary experimental surgical intervention, such as partial hepatectomy, portal vein ligation and liver transplantation.
Acquisition of hepatic hemodynamic data in rodents requires the proposed invasive procedure. Hepatic perfusion cannot be obtained non-invasively. However, there are alternatives for the acquisition of the systemic blood pressure. Monitoring techniques such as the tail cuff technique8 have been utilized for acquiring the blood pressure in both rats and mice. The tail cuff technique can be applied in conscious animals. When measuring the blood pressure, the animal needs to be placed and fixed in a specific uncomfortable position. In the manual of the tail-cuff device, the manufacturer states that mice may become nervous and stressed which may diminish the circulation in the tail. Under that circumstance, the peripheral blood pressure acquired in the tail may be much lower than the central blood pressure.
The full monitoring procedure was performed with an integrated multiple-channel monitor using a series of sensors for data acquisition. The blood pressure was obtained by inserting a catheter into the respective vessel after careful microsurgical dissection and exposure under the microscope. The flow rate was measured by placing a transonic flow probe around each vessel.
We already reported a similar intraoperative monitoring procedure for rats resulting in a comprehensive series of physiological hemodynamic data comparable to single data reported from other groups7. Therefore we considered this procedure to represent a good basis for adapting it to the mouse, a species 10-fold smaller than the rat. The key difference to the rat procedure is the use of Millar catheters for acquiring blood pressure data instead of a fluid-based catheter system. Flow data were also acquired with transonic flow probes, just much smaller ones than for the corresponding rat vessels.
Due to the small size of the animal, instrumentation of mice is technically challenging, but feasible. Once instrumentation is completed, data acquisition and primary life data analysis is simple, since a predefined setting file can be used. The setting file has to be defined once at the beginning of a series of experiments and can be stored and used for all subsequent experiments.
Up to now we applied this procedure to assess hepatic hemodynamic effects in acute experiments. We measured CAP and PVP before and immediately after 70% partial hepatectomy (PH) and in clamping/de-clamping experiments. We clamped the hepato-duodenal ligament of the right lobe representing 20% of the liver mass followed by brief (5min) clamping of the median and left lateral lobe representing totally 90% of the liver mass. De-clamping started with releasing the clamp from the right lobe followed by freeing the median and left lateral lobe. Maximal clamping time was below 10 min.

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			<td height="21" style="height:21px;width:216px;">10-0 prolene</td>
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			<td height="21" style="height:21px;width:216px;">Tail cut-off device&#160;</td>
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			<td height="21" style="height:21px;width:216px;">LabChart7</td>
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			<td style="width:167px;">data&#160; analysis software&#160;</td>
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monitoring of systemic and hepatic hemodynamic parameters in mice

The use of mouse models in experimental research is of enormous importance for the study of hepatic physiology and pathophysiological disturbances. However, due to the small size of the mouse, technical details of the intraoperative monitoring procedure suitable for the mouse were rarely described. Previously we have reported a monitoring procedure to obtain hemodynamic parameters for rats. Now, we adapted the procedure to acquire systemic and hepatic hemodynamic parameters in mice, a species ten-fold smaller than rats. This film demonstrates the instrumentation of the animals as well as the data acquisition process needed to assess systemic and hepatic hemodynamics in mice. Vital parameters, including body temperature, respiratory&#160;rate&#160;and heart&#160;rate were recorded throughout the whole procedure. Systemic hemodynamic parameters consist of carotid artery pressure (CAP) and central venous pressure (CVP). Hepatic perfusion parameters include portal vein pressure (PVP), portal flow rate as well as the flow rate of the common hepatic artery (table 1). Instrumentation and data acquisition to record the normal values was completed within 1.5 h. Systemic and hepatic hemodynamic parameters remained within normal ranges during this procedure.
This procedure is challenging but feasible. We have already applied this procedure to assess hepatic hemodynamics in normal mice as well as during 70% partial hepatectomy and in liver lobe clamping experiments. Mean PVP after resection (n= 20), was 11.41&#177;2.94 cmH2O which was significantly higher (P&#60;0.05) than before resection (6.87&#177;2.39 cmH2O). The results of liver lobe clamping experiment indicated that this monitoring procedure is sensitive and suitable for detecting small changes in portal pressure and portal flow rate. In conclusion, this procedure is reliable in the hands of an experienced micro-surgeon but should be limited to experiments where mice are absolutely needed.

Vital parameters of the mice such as respiratory rate and heart rate are obviously much higher than in rat. Mean systemic blood pressure and jugular vein pressure are similar to rat values and even similar to the human data.
Hepatic hemodynamic data are obviously different. We obtained normal values from 8 mice. Portal blood flow in normal mice ranged between 1.6 to 2.3 ml/min. Flow in the common hepatic artery ranged from 0.10 to 0.35 ml/min. Portal vein pressure in normal animals was in the ...

Watch this Scientific Journal Video about Monitoring of Systemic and Hepatic Hemodynamic Parameters in Mice at JoVE.com

Monitoring of Systemic and Hepatic Hemodynamic Parameters in Mice

This film demonstrates how to acquire systemic and hepatic hemodynamics in mice. The whole monitoring includes acquisition of vital parameters, systemic blood pressure, central venous pressure, common hepatic artery flow rate, and portal vein pressure as well as the portal flow rate in mice.

The use of mouse models in experimental research is of enormous importance for the study of hepatic physiology and pathophysiological disturbances. ...

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Medicine

The bm12 Inducible Model of Systemic Lupus Erythematosus (SLE) in C57BL/6 Mice

Systemic lupus erythematosus (SLE) is an autoimmune disease with diverse clinical and immunological manifestations. Several spontaneous and inducible animal models mirror common components of human disease, including the bm12 transfer model. Upon transfer of bm12 splenocytes or purified CD4 T cells, C57BL/6 mice rapidly develop large frequencies of T follicular helper cells (Tfh), germinal center (GC) B cells, and plasma cells followed by high levels of circulating anti-nuclear antibodies. Since this model utilizes mice on a pure C57BL/6 background, researchers can quickly and easily study disease progression in transgenic or knockout mouse strains in a relatively short period of time. Here we describe protocols for the induction of the model and the quantitation Tfh, GC B cells, and plasma cells by multi-color flow cytometry. Importantly, these protocols can also be used to characterize disease in most mouse models of SLE and identify Tfh, GC B cells, and plasma cells in other disease models.

The bm12 Inducible Model of Systemic Lupus Erythematosus SLE in C57BL/6 Mice

The transfer of bm12 lymphocytes into a C57BL/6 recipient is an established model of systemic lupus erythematosus. Here we describe how to initiate disease using this model and how to characterize T follicular helper cells, germinal center B cells and plasma cells by flow cytometry.

Systemic lupus erythematosus (SLE) is an autoimmune disease with diverse clinical and immunological manifestations. Several spontaneous and inducible ...

Uncontrolled Hemorrhagic Shock Modeled via Liver Laceration in Mice with Real Time Hemodynamic Monitoring

Uncontrolled hemorrhage is an important cause of preventable deaths among trauma patients. We have developed a murine model of uncontrolled hemorrhage via a liver laceration that results in consistent blood loss, hemodynamic alterations, and survival.
Mice undergo a standardized resection of the left-middle lobe of the liver. They are allowed to bleed without mechanical intervention. Hemostatic agents can be administered as pre-treatment or rescue therapy depending on the interest of the investigator. During the time of hemorrhage, real-time hemodynamic monitoring via a left femoral arterial line is performed. Mice are then sacrificed, blood loss is quantified, blood is collected for further analysis, and organs are harvested for analysis of injury. Experimental design is described to allow for simultaneous testing of multiple animals.
Liver hemorrhage as a model of uncontrolled hemorrhage exists in the literature, primarily in rat and porcine models. Some of these models utilize hemodynamic monitoring or quantify blood loss but lack consistency. The present model incorporates quantification of blood loss, real-time hemodynamic monitoring in a murine model that offers the advantage of using transgenic lines and a high-throughput mechanism to further investigate the pathophysiologic mechanisms in uncontrolled hemorrhage.

Uncontrolled hemorrhage, an important cause of mortality among trauma patients, can be modeled using a standard liver laceration in a murine model. This model results in consistent blood loss, survival, and allows for testing hemostatic agents. This article provides the step-by-step process to perform this valuable model.

Uncontrolled hemorrhage is an important cause of preventable deaths among trauma patients. We have developed a murine model of uncontrolled hemorrhage via ...

Invasive Hemodynamic Characterization of the Portal-hypertensive Syndrome in Cirrhotic Rats

This is a detailed protocol describing invasive hemodynamic measurements in cirrhotic rats for the characterization of portal hypertensive syndrome. Portal hypertension (PHT) due to cirrhosis is responsible for the most severe complications in patients with liver disease. The full picture of the portal hypertensive syndrome is characterized by increased portal pressure (PP) due to the increased intrahepatic vascular resistance (IHVR), hyperdynamic circulation, and increased splanchnic blood flow. Progressive splanchnic arterial vasodilation and increased cardiac output with elevated heart rate (HR) but low arterial pressure characterizes the portal hypertensive syndrome.
Novel therapies are currently being developed that aim to decrease PP by either targeting IHVR or increased splanchnic blood flow &#8212; but side effects on systemic hemodynamics may occur. Thus, a detailed characterization of portal venous, splanchnic, and systemic hemodynamic parameters, including measurement of PP, portal venous blood flow (PVBF), mesenteric arterial blood flow, mean arterial pressure (MAP), and HR is needed for preclinical evaluation of the efficacy of novel treatments for PHT. Our video article provides the reader with a structured protocol for performing invasive hemodynamic measurements in cirrhotic rats. In particular, we describe the catheterization of the femoral artery and the portal vein via an ileocolic vein and the measurement of portal venous and splanchnic blood flow via perivascular Doppler-ultrasound flow probes. Representative results of different rat models of PHT are shown.

Here we describe a detailed protocol for invasive measurements of hemodynamic parameters including portal pressure, splanchnic blood flow, and systemic hemodynamics in order to characterize the portal hypertensive syndrome in rats.

This is a detailed protocol describing invasive hemodynamic measurements in cirrhotic rats for the characterization of portal hypertensive syndrome. ...

Invasive Hemodynamic Monitoring of Aortic and Pulmonary Artery Hemodynamics in a Large Animal Model of ARDS

One of the leading causes of morbidity and mortality in patients with heart failure is right ventricular (RV) dysfunction, especially if it is due to pulmonary hypertension. For a better understanding and treatment of this disease, precise hemodynamic monitoring of left and right ventricular parameters is important. For this reason, it is essential to establish experimental pig models of cardiac hemodynamics and measurements for research purpose. 
This article shows the induction of ARDS by using oleic acid (OA) and consequent right ventricular dysfunction, as well as the instrumentation of the pigs and the data acquisition process that is needed to assess hemodynamic parameters. To achieve right ventricular dysfunction, we used oleic acid (OA) to cause ARDS and accompanied this with pulmonary artery hypertension (PAH). With this model of PAH and consecutive right ventricular dysfunction, many hemodynamic parameters can be measured, and right ventricular volume load can be detected. 
All vital parameters, including respiratory rate (RR), heart rate (HR) and body temperature were recorded throughout the whole experiment. Hemodynamic parameters including femoral artery pressure (FAP), aortic pressure (AP), right ventricular pressure (peak systolic, end systolic and end diastolic right ventricular pressure), central venous pressure (CVP), pulmonary artery pressure (PAP) and left arterial pressure (LAP) were measured as well as perfusion parameters including ascending aortic flow (AAF) and pulmonary artery flow (PAF). Hemodynamic measurements were performed using transcardiopulmonary thermodilution to provide cardiac output (CO). Furthermore, the PiCCO2 system (Pulse Contour Cardiac Output System 2) was used to receive parameters such as stroke volume variance (SVV), pulse pressure variance (PPV), as well as extravascular lung water (EVLW) and global end-diastolic volume (GEDV). Our monitoring procedure is suitable for detecting right ventricular dysfunction and monitoring hemodynamic findings before and after volume administration.

We present a protocol of creating right ventricular dysfunction in a pig model by inducing ARDS. We demonstrate invasive monitoring of left and right ventricular cardiac output using flow probes around the aorta and the pulmonary artery, as well as blood pressure measurements in the aorta and pulmonary artery.

One of the leading causes of morbidity and mortality in patients with heart failure is right ventricular (RV) dysfunction, especially if it is due to ...

Measurement of the Hepatic Venous Pressure Gradient and Transjugular Liver Biopsy

Here we provide a detailed protocol describing the clinical procedure of hepatic venous pressure gradient (HVPG) measurement in patients with advanced chronic liver disease followed by an instruction for transjugular biopsy. Under local anesthesia and ultrasound guidance, a catheter introducer sheath is placed in the right internal jugular vein. Using&#160;fluoroscopic guidance, a balloon catheter is advanced into the inferior vena cava (IVC) and inserted into a large hepatic vein. Correct and sufficient wedge position of the catheter is ensured by injecting contrast media while the balloon is blocking the outflow of the cannulated hepatic vein. After calibrating the external pressure transducer, continuous pressure recordings are obtained with triplicate recordings of the wedged hepatic venous pressure (WHVP) and free hepatic venous pressure (FHVP). The difference between FHVP and WHVP is referred to as HVPG, with values &#8805;10 mm Hg indicating clinically significant portal hypertension (CSPH). Before removing the catheter, pressure readings obtained in the IVC at the same level, as well as the right atrial pressure are recorded.
Finally, a transjugular liver biopsy can be obtained via the same vascular route. Different systems are available; however, core biopsy needles are preferred over aspiration needles, especially for cirrhotic livers. Again, under fluoroscopic guidance a biopsy needle introducer sheath is advanced into an hepatic vein. Next, the transjugular biopsy needle is gently advanced through the introducer sheath: (i) in case of aspiration biopsy, the needle is advanced into the liver parenchyma under aspiration and then removed quickly, or (ii) in case of a core biopsy, the cutting-mechanism is triggered inside the parenchyma. Several separate passages can be safely performed to obtain sufficient liver specimens via transjugular biopsy. In experienced hands, the combination of these procedures takes about 30-45 min.

Here, we present a protocol for measurement of hepatic venous pressure gradient (HVPG),the gold standard to diagnose clinically significant portal hypertension. Moreover, we describe how to perform a transjugular liver biopsy within the same session.

Here we provide a detailed protocol describing the clinical procedure of hepatic venous pressure gradient (HVPG) measurement in patients with advanced ...

Standardized Hemorrhagic Shock Induction Guided by Cerebral Oximetry and Extended Hemodynamic Monitoring in Pigs

Hemorrhagic shock ranks among the main reasons for severe injury-related death. The loss of circulatory volume and oxygen carriers can lead to an insufficient oxygen supply and irreversible organ failure. The brain exerts only limited compensation capacities and is particularly at high risk of severe hypoxic damage.This article demonstrates the reproducible induction of life-threatening hemorrhagic shock in a porcine model by means of calculated blood withdrawal. We titrate shock induction guided by near-infrared spectroscopy&#160;and extended hemodynamic monitoring to display systemic circulatory failure, as well as cerebral microcirculatory oxygen depletion. In comparison to similar models that primarily focus on predefined removal volumes for shock induction, this approach highlights a titration by means of the resulting failure of macro- and microcirculation.

Hemorrhagic shock is a severe complication in seriously injured patients, which leads to life-threatening oxygen undersupply. We present a standardized method to induce hemorrhagic shock via blood withdrawal in pigs that is guided by hemodynamics and microcirculatory cerebral oxygenation.

Hemorrhagic shock ranks among the main reasons for severe injury-related death. The loss of circulatory volume and oxygen carriers can lead to an ...

Invasive Hemodynamic Assessment for the Right Ventricular System and Hypoxia-Induced Pulmonary Arterial Hypertension in Mice

Pulmonary arterial hypertension (PAH) is a chronic and severe cardiopulmonary disorder. Mice are a popular animal model used to mimic this disease. However, the evaluation of right ventricular pressure (RVP) and pulmonary artery pressure (PAP) remains technically challenging in mice. RVP and PAP are more difficult to measure than left ventricular pressure because of the anatomical differences between the left and right heart systems. In this paper, we describe a stable right heart hemodynamic measurement method and its validation using healthy and PAH mice. This method is based on open-chest surgery and mechanical ventilation support. It is a complicated procedure compared to closed chest procedures. While a well-trained surgeon is required for this surgery, the advantage of this procedure is that it can generate both RVP and PAP parameters at the same time, so it is a preferable procedure for the evaluation of PAH models.

Here, we present a protocol to perform an invasive hemodynamic assessment of the right ventricle and pulmonary artery in mice using an open-chest surgery approach.

Pulmonary arterial hypertension (PAH) is a chronic and severe cardiopulmonary disorder. Mice are a popular animal model used to mimic this disease. ...

Dosage-Dependent Induction of Endotoxemia in Pigs via LPS Infusion

Lipopolysaccharide Infusion as a Porcine Endotoxemic Shock Model

Sepsis and septic shock are frequently encountered in patients treated in intensive care units (ICUs) and are among the leading causes of death in these patients. It is caused by a dysregulated immune response to an infection. Even with optimized treatment, mortality rates remain high, which makes further insights into the pathophysiology and new treatment options necessary. Lipopolysaccharide (LPS) is a component of the cell membrane of gram-negative bacteria, which are often responsible for infections causing sepsis and septic shock. 
The severity and high mortality of sepsis and septic shock make standardized experimental studies in humans impossible. Thus, an animal model is needed for further studies. The pig is especially well suited for this purpose as it closely resembles humans in anatomy, physiology, and size. 
This protocol provides an experimental model for endotoxemic shock in pigs by LPS infusion. We were able to reliably induce changes frequently observed in septic shock patients, including hemodynamic instability, respiratory failure, and acidosis. This will allow researchers to gain valuable insight into this highly relevant condition and evaluate new therapeutic approaches in an experimental setting.

Author Spotlight: Induction of Experimental Endotoxemic Shock in Pigs for Studying Hemodynamic and Respiratory Failure

We provide a protocol for an experimental endotoxemic shock model in pigs by infusion of lipopolysaccharide.

Sepsis and septic shock are frequently encountered in patients treated in intensive care units (ICUs) and are among the leading causes of death in these ...

Oleic Acid&amp;#45;Induced Acute Respiratory Decompensation in Pigs

A Porcine Model of Acute Respiratory Failure with a Continuous Infusion of Oleic Acid

This protocol outlines an acute respiratory distress model utilizing centrally administered oleic acid infusion in Yorkshire pigs. Prior to experimentation, each pig underwent general anesthesia, endotracheal intubation, and mechanical ventilation, and was equipped with bilateral&#160;jugular vein central vascular access catheters. Oleic acid was administered through a dedicated pulmonary artery catheter at a rate of 0.2 mL/kg/h. The infusion lasted for 60-120 min, inducing respiratory distress. Throughout the experiment, various parameters including heart rate, respiratory rate, arterial blood pressure, central venous pressure, pulmonary artery pressure, pulmonary capillary wedge pressure, end-tidal carbon dioxide, peak airway pressures, and plateau pressures were monitored. Around the 60 min mark, decreases in partial arterial oxygen pressure (PaO2) and fraction of oxygen-saturated hemoglobin (SpO2) were observed. Periodic hemodynamic instability, accompanied by acute increases in pulmonary artery pressures, occurred during the infusion. Post-infusion, histological analysis of the lung parenchyma revealed changes indicative of parenchymal damage and acute disease processes, confirming the effectiveness of the model in simulating acute respiratory decompensation.

Author Spotlight: Exploring Venous Waveforms for Non&amp;#45;Invasive Respiratory Monitoring in Pigs

Infusing oleic acid continuously into the pulmonary artery of an anesthetized adult pig induces acute respiratory failure, enabling controlled experimentation during acute respiratory decompensation.

This protocol outlines an acute respiratory distress model utilizing centrally administered oleic acid infusion in Yorkshire pigs. Prior to ...

Ascending Aortic Banding and Left Ventricle/Aorta Catheterization in Swine for Pressure Measurements and Hemodynamic Monitoring 

After performing arterial cannulation in an anesthetized pig, using the cardiac ultrasound transducer, locate the position of the ascending aorta. Then mark the incision site and disinfect the chest of the animal. Using a scalpel, make a two to three centimeter skin incision at the level of the three-fourth intercostal space.Then dissect the underlying fascia and muscle layers until the intercostal space is reached. Stop the ventilation without positive and expiratory pressure. Incise the intercostal muscles to enter the thorax.Then increase the incision to allow the placement of the retractor blades. Retract the ribs and visualize the underlying structures. Using minimally invasive cardiac surgery forceps and scissors, open the pericardium.Then use with sterile gauze to retract the left atria and any lung tissue covering the view of the aorta. Carefully separate the aorta from the pulmonary artery until the transverse pericardial sinus is reached. To facilitate aortic catheterization, place a radiopaque marker in the banding area.Position the ePTFE graft or the nylon band around the ascending aorta. Connect a dual hemostasis valve adapter to a six French MP1 guide catheter, and flush it with heparinized saline. Preload the guide catheter with a 260-centimeter 0.035-inch J-tip guidewire and introduce this assembly through the femoral arterial sheath.Under fluoroscopic guidance, advance the guide wire and guide the catheter into the ascending aorta. When the aortic valve is identified, carefully cross it with a guidewire and introduce the guide catheter into the left ventricle. Check pressure traces to confirm left ventricle positioning.Next, remove the guidewire while leaving the guide catheter in the left ventricle. After aspirating the blood, flush the catheter with sterile saline and ensure no air bubbles are present in the catheter. After advancing two high-fidelity pressure sensors through the dual hemostasis valve adapter, pull the guide catheter back into the ascending aorta distally to the radiopaque marker placed on the banding site.While leaving one of the high-fidelity pressure sensors in the left ventricle, confirm the catheter position using pressure traces. After left ventricle catheterization, close the nylon band one click at a time while closely monitoring pressures. Place sterile plastic tubing on the nylon band end to avoid accidental damage to the surrounding structures.for ePTFE ends, constrict the band using 45-degree forceps. Monitor the pressure to estimate the relative location of the constriction. Finally, place a titanium hemoclip on the forceps position.The use of high fidelity pressure sensors enables obtaining high quality pressure signals, allowing real time and accurate calibration of the stenosis. Transthoracic echocardiography confirm significant aortic stenosis immediately after surgery and during follow-up. Banding surgery resulted in significant aortic stenosis and left ventricular concentric hypertrophy.Post-mortem macroscopic analysis of the heart revealed larger hearts and a thicker left ventricular wall.