 Good morning, everyone. My name is Marcin Von Sovic. I'm anesthesiologist and critical care physician practicing at Toronto General Hospital. I'm also a member of perioperative echocardiography group in our site. It's my pleasure to lead this session. I was curator by Andrew Deno. I don't think Andrew needs any presentation or introduction. He is truly the friend of our meeting for the last 21 years. He presented on most of our meetings. He rescued us in emergency situation when some lectures were cancelled in the very last moment for personal reasons. The title of the session is Extracaldiac ultrasound and definitely Andrew and his group are pioneers. He assembled three lecturers. I'm looking forward. I listened to all lectures yesterday because of my role. It's fascinating. What else I can add? Andres, professor of anesthesia and critical care in Montreal Heart Institute and University of Montreal. He published over 300 papers, wrote multiple chapters. He's editor of three books and I believe many of us are using them as a daily reference. And among your multiple research interests is Extracaldiac ultrasound. Andres, we are looking forward for your presentation. I know that you are also closing with some cases. Just as a housekeeping reminder, please post your questions or Q&A part and we will moderate discussion at the end of this session. Andres, floor is yours. Thank you so much. Thanks again for the invitation. I think we're ready to start so we could start the presentation now. They were pre-recorded by our team. So enjoy. My name is Andres De Noux. I'm professor of anesthesia at the University of Montreal. I'd like to thank the organizer for inviting me to discuss with you about trans-gastric abdominal ultrasound. I work at the Montreal Heart Institute as a cardiac anesthesiologist and these are my disclosures. I'm also supported by the Montreal Heart Institute Foundation and the Richard Kaufman Diamond Fund in anesthesia and critical care. My objectives are to present an overview of extracaldic organs in the vasculature that T can interrogate, to describe normal intrabdominal organs using T imaging, and also to identify common pathologies beyond the kidney and the liver. This presentation will be done in collaboration with Dr. Jean-Simon La Dancette, who is a cardiologist and also a critical care fellow at the University of Montreal, and also Dr. William Boubien-Soudigny, who is a nephrologist and the researcher at the University of Montreal. The classical application of extracardiac T are lung and upper GI cancer differential diagnosis and staging, and also ciliate blockade for pancreatic cancer related pain. However, the perioperative applications of these modalities include determining the cause of hypoxemia, which is done through transophageal lung ultrasound or TILUS, to identify any extracardiac cause of hemodynamic instability, and to monitor splenchnic and renal perfusion, which can be done using transgastric abdominal ultrasound or TGOs. In this article on the practice guideline for perioperative TEE, it is mentioned that TEE should be used in unexplained persistent hypotension or hypoxemia. Importantly, those conditions can be extracardiac. Similar to those James Bond glasses, extracardiac TEE will allow you to identify with ultrasound unsuspected dangers for your patients. In 2016, Alex Kaveyes reported the use of TILUS, and in 2021, we published this article on transgastric abdominal ultrasound that we will discuss. The following examples will be part also of our upcoming TEE multimedia manual third edition, which is scheduled for 2024 with all those editors. This is how we're using extracardiac TEE. So if you have hemodynamic instability but hypoxemia, then you would consider looking at the heart, but mostly looking at the long and performing transophageal long ultrasound. However, if there's no hypoxemia, then you would consider that you may have a cardiogenic or non-cardiogenic hemodynamic instability, and for the non-cardiogenic, those are the conditions that can be diagnosed with transgastric abdominal ultrasound. With transgastric abdominal ultrasound, most upper abdominal structures can be identified. The position of the TEE probe can easily be described. Solid organs can be interrogated, but also the Arta, its branches, and also you can assess perfusions and also signs of venous congestion. So in our article on TEE GUS, we identified 10 specific views and described their usefulness in perioperative medicine. Some of those views are interior, some views are on the right side, posterior, and on the left side. So the stomach is interior, to some extent. The splinic vein and the superior mesenteric vein are posterior to the stomach. They join together to form the portal vein. The kidneys are posterior. The spleen is between the stomach and the left kidney. The pancreas is posterior to the stomach, but anterior to the splinic vein. This is the large transverse colon, which is just below the stomach. And finally, on the right side there is the liver, with an interior extension with the left liver lobe. In order to scan vessels such as the aorta or the IVC, the ultrasound beam is electronically positioned at zero degree, and we will slowly advance the probe back and forth to identify the structures. In order to allow scanning of solid organs like the liver, the ultrasound beam will be electronically rotated to 90 degree. We will then perform axial rotation on the ultrasound beam from the left to the right. Using a TE probe outside the heart can change the orientation of the 2D image from the ultrasound beam. Normally from a transgastric view at zero degree, the TE ultrasound beam is relatively interior to the TE probe. The position of the dual knob on the TE probe will follow the position of the beam. In a normal neutral position it will describe as a clock, 12 o'clock. In this example, when we obtain a transgastric view, what you see on the right side of the screen is the left structure of the patient, and what you see on the left side of the screen is the right-sided structure. At zero degree, the dual rotating knob undergo an axial rotation. For instance, at 6 o'clock, right portion of the screen will correspond to the right posterior structures, and the left posterior position of the screen corresponds to the left-sided structure. When the probe is rotated at 90 degree, the right side of the screen will always display cephalate structure. The left of the screen will always display codal structure, and they will be interior-right, posterior, and left with axial rotation from 12, 3, 6, and 9 o'clock. Precise position of the terasic and abdominal structure can be done using the depth marker on the TE probe and the 2D orientation of the dual rotating knob at 3, 6, 9, or 12 o'clock for both transophageal lung and transomintegos. In order to use venous Doppler, there are some specific rules. First, very important to reduce the velocity scale from 5 to 20 a centimeter per second. Second, a normal Positile venous Doppler velocity, such as the epithetic vein, is always abnormal if not Positile, and a normal non- Positile venous Doppler, as the portal or the splenic vein, is always abnormal if Positile. Finally, if there's an abnormal venous Doppler, confirm it in another site, and this is the concept of the vexus core. In this view of the kidney, the color scale was reduced to 3 centimeter per second. Higher velocity scale could mask preserved renal perfusion. You will be able to notice that some vendors do not offer the ability to go below 15 centimeter per second. This is an example of a splenic vein. What you can do in those cases is to use tissue Doppler, and then you'll be able to identify very low velocity scale on your venous Doppler signals. Those are the rules for arterial Doppler interrogation. It's important to analyze your waveform. First, there should be a rapid systolic portion in a normal arterial Doppler signal. If you have pulse of stardust, it can be cardiac, but it can be extra cardiac such as vascular stenosis. There are quantitative values. The peak velocities, we will typically use pulse width Dopplers on the S-seria velocities are more than 200 centimeter per second, which would indicate a stenosis. The systolic velocities are definitively related to your stroke volume and your cardiac output, and the dastolic velocities are mostly related to resistance. And from those values, you can calculate the resistance index or the possibility index. And very important, if you have an abnormal arterial signal, never analyze it in isolation. This is an abnormal arterial Doppler signal from the splenic artery. Note the dastolic reversal and the very high resistance. However, you have a similar signal on the transcranial Doppler with low dastolic velocities. And this was secondary to severe aortic regurgitation signal obtained just before aortic valve replacement. Those are the normal arterial velocities of the abdominal vessels. Stomach is the first portion of the Tegos exam. We can examine the stomach structure, the content, the wall, but also the elements which are external to the stomach. All the transgastric abdominal ultrasound views originate from the stomach. The Tee probe is in the stomach, which surrounds it. The ultrasound beam can be at zero degree, or as shown here, adjusted to obtain the largest portion of the stomach, which can vary among patient. This is an oblique view that allow visualization of the largest portion of the stomach. This is the corresponding ultrasound image. This is a 2D view of an empty stomach and a 3D view of a stomach with clear fluid, where you can see the normal cirrus wall of the stomach. The role of the stomach view is to identify for stomach, upper GI bleed, bowel wall edema, gastric varices, and peritoneal fluid. This is a stomach filled with fluid, and this is a full stomach with food particles. 61 year old woman, cardiogenic shock with ECMO install. In this patient, gastric distention and full stomach was present. This can be the result of gut hyperperfusion and lead to abdominal compartment syndrome, which can be fatal if unrecognized. These are unstable patient, one with upper GI bleed, and this one has blood clots in the stomach. This is an example of the use of color Doppler around the stomach wall. Those are gastric varices in a patient with liver cirrhosis. 72 year old woman, undergoing both mitral and tracheal spit valve replacement. This patient has gastric edema, more than four millimeter wall thickness, which is often observed in patients with splenchnic penis congestion as a result of right heart failure and pulmonary hypertension. 50 year old hemodynamic unstable patient after a cardiac arrest. This patient had a significant hyperdynamic heart with almost leventcular alfotrack obstruction. He had free peritoneal fluid present anterior to the stomach and around the tip of the left lobe of the liver as shown here. So again, in patients who are unstable with a normal heart, it is relevant to look outside the heart as in this case. When the T probe is turned to the right, you can examine the inferior vena cava for its tracheal consent, respiratory variation, the external content. You can also interrogate the hepatic vein using Doppler. And you can also look at the liver again for the intrinsic content and the external structures. This is an interoperative view of the inferior vena cava as it enters into the right atrium to the tox just above the diaphragm. So this is the inferior vena cava. From the stomach, a transverse view of the IVC and the hepatic vein can be obtained. The ultrasound being can be initially at zero degree. And this would correspond to the ultrasound image that you would see in this position. From the stomach, a longitudinal view of the inferior vena cava and the right hepatic vein can be obtained. The ultrasound beam is aligned on the inferior vena cava at 90 plus or minus 10 degree. And this is the corresponding ultrasound image that you would see in this patient. The transverse orientation of the hepatic vein is not necessarily at zero degree, but by minus 30 plus or minus 10 degree. In order to visualize the three hepatic veins, it's often preferable to move from zero to 140 degree as in this example. You will then be able to see the middle hepatic vein, the right hepatic vein and the left hepatic vein. This is a patient in which the three hepatic veins are clearly seen at 157 degree. So these are the hepatic vein. However, rotating the image on the ultrasound system will allow easier analysis of the structures. Dr. Lalancet will discuss in more detail the Doppler analysis of the hepatic and the portal vein also. So another relevant diagnosis that can be made with liver ultrasound is acides, but also liver cirrhosis as shown here by the abnormal contour of the liver or the round liver edge. This is an example of a carcinoid tumor that was present in a patient with severe tracheuspid regurgitation. Note the irregular texture of the liver. The portal triad view can be useful for several reasons. The portal vein looking at intrinsic content, Doppler velocities, the hepatic artery and also the bile duct. The portal vein is anterior to the inferior vena cava, but not parallel and it is slightly oblique. From the stomach, a longitudinal view of the origin of the main portal vein can be obtained at about 70 degrees. The portal vein is formed by the junction of the splenic vein and the mesenteric vein. This is the corresponding ultrasound image where you can also see a portion of the inferior vena cava. In patients who have undergone a colisistectomy, you will often see two parallel portal veins. The real one is this one, but the following corresponds to a dilated bile duct. The term double barrel gun is used to describe this condition. 85 year old man, hypotensive with lactic acidosis after corneatory revascularization and intratheic balloon pump removal. This patient had a normal nurse which to some extent exclude the cardiogenic condition. Indeed, the transophageal echocardiographic exam was unchanged. However, when we examined the abdomen and we look at the portal vein, there was a significant amount of air into the portal vessel. A CT scan was ordered and you can see air which was present in the left lobe of the liver as a result of mesenteric ischemia. Again, a normal cerebral and somatic saturation indicated a non-cardiogenic type of shock. In this patient, you can appreciate again the tick and stomach, but also asides as a result of venous congestion and not surprisingly a normal portal vein possibility. This is a normal pericardium and this one is from a 63 year old man undergoing mitral valve replacement. Note the significant pericardial venous congestion which was associated with elevated central venous pressure, large V-wave and also portal possibility. Dr. Lalancette will discuss this in more detail. The aorta and its branches can be examined with transgastric abdominal ultrasound. In addition, all those vessels can also be analyzed. From the stomach, posterior rotation of the T probe will allow visualization of the celiac trunk at zero degree. This is the corresponding ultrasound image that you will see, but remember in this position the right is on the right and the left is on the left side of the screen. This is the aorta, this is the celiac trunk, this is the hepatic artery, the splinic artery and the pancreas. This image is typically called the whale tail sign. From the same previous position, T probe advance will allow visualization of the superior mesenteric artery and the surrounding vessel. This is the corresponding ultrasound image. In this position, remember again that the right side structure will be on the right, left side structure on the left. This is an example where you can see the aorta, the superior mesenteric artery, the right renal artery with the corresponding arterial Doppler signal, the left renal vein with the corresponding versatile venous signal and the superior mesenteric vein, which normally is a continuous non-positile signal. The role of those views are the following. They can be used to monitor your patient during arctic dissection or vascular stenting to evaluate also the adequate position of the enterotic balloon pump to detect compromise the splinic flow with celiac trunk and mesenteric artery monitoring. And finally, to diagnose splinic vascular stenosis and the nutcracker syndrome. We often verify the cephalate position of the enterotic balloon pump in the aorta, but less frequently the codial position. In this study published in circulation in 2010, Rastan et al. look at the visceral arterial compromise during enterotic balloon pump therapy. They look at 63 patients with an enterotic balloon pump requiring a CT scan. And based on the radiography, the proximal balloon position was correct in 96.8%, but appropriate only on 30% based on CT scan. In 97% of those patients, there was at least one visceral artery which was compromised, the celiac trunk in 97% of the time and the superior mesenteric artery 87% and the renal artery about two turns of the time. The paratomy for mesenteric ischemia was required in 23.8% of those patients and the hospital mortality was 60%. This is a 69-year-old woman redo aortic valve replacement and during the operation, the late lactate went up to 5.1%. When you look at the superior mesenteric artery, you can see an increase in the adiasing which suggests that this patient has a stenosis. Indeed, her peak velocity was 3 m per second. Fortunately, this patient died postoperatively from mesenteric ischemia and lactate increased up to 20 mm per liter. Left side structure will include the spleen in which the splenic vein and the splenic artery can be interrogated, but also the dimension, the content, the dimension, the content and the external structure around the spleen. From the stomach, left-sided rotation of the T-probe can result in a transverse view of the spleen. The ultrasound beam can be initially at zero degree and this would correspond to the ultrasound image that you would see on your TEE system. This is an example of a view of the spleen and the hyalum, the systolic artery velocities and the normal continuous splenic vein dopper signal can be analyzed. The splenic view can be used to monitor RV dysfunction which is associated with venous congestion and also evaluation of response to medical treatment. We can also diagnose splenic rupture, cyst and also abscess in the spleen. Presence of free abdominal fluid can also be detected in this view. This is a 57-year-old patient after cardiac arrest. He's a very unstable necmo. He had his cardiac arrest after hockey game. This is the splenic view. You can see the stomach and this is the spleen with free blood to your right portion of the screen and blood clot to the spleen. This is the lever and his hemoperitoneum was secondary to an hepatic laceration from the cardiac massage. The renal exam will be discussed in more detail by Dr. William Beaubien-Souligny. This is a transverse and a longitudinal pancreatic view which are mostly useful to interrogate also the splenic vein and the splenic artery. This view is similar to the supérieure mesenteric artery view but we will focus on the splenic vein which is just under the pancreas. The ultrasound beam will be typically at zero degree and this is the corresponding ultrasound image. So this is an example of a normal splenic vein with color Doppler. The pancreatic view can be used to interrogate the splenic vein and detect the severity of RV systolic and dastoid dysfunction. In addition we can use it to evaluate response to medical treatment. That is the return report or experience using this view before the procedure where you can see some degree of velocity immediately after bypass where you can see a normal but reduced velocity and then after return of cell saver fluid where you can appreciate the increase in velocity. She mentioned that the portal vein is easily made with surface ultrasound but the alignment is more problematic with TE. Doppler interrogation of the splenic vein with TE is much more easy to obtain. 77 year old man during off-punk bypass you have the hemodynamic value. There's a normal right ventricular pressure waveform. The brain saturation is normal and there's a normal continuous splenic venous Doppler. 56 year old woman to post bypass after aortic valve replacement. There is a normal right ventricular waveform with the dastolic slope. There is significant splenic venous Doppler possibility with also brain desaturation. So in conclusion TE is more than transsophageal echocardiography. TE is transsophageal echography. TELUS is indicated if you have a patient who is hypoxemic or abnormal blood gas you need to examine the lung. If you have an innermodernally unstable patient with a normal looking heart or hyperdynamic or left ventricular outflow tract obstruction and TELUS is normal it's important to examine the abdomen. TGAS in fact represent a new area of research in perioperative anesthesia. Thank you for your attention. Thank you. Thank you Andrea for fantastic lecture. I'm sure there will be plenty of questions at the end of the session.