 Hello, ladies and gentlemen. My name is Mike Lee. I'm a clinical fellow from the Division of Cardiovascular Surgery at the Hospital for Sick Children. Thank you very much for allowing me to talk about incidental TR from Surgeon's perspective. So, TREC-Hospital Regurgitation is a common presentation in adult cardiac surgery. As a matter of fact, the TR prevalence has been shown to be similar to aortic stenosis and mitral regurgitation. So, in the US, more than 1.6 million individuals are estimated to have moderate or greater TR, and the prevalence of moderate or greater TR has been proposed to be around 0.55% that may be as high as 3% after age 75. The ideology of TR can be primary or secondary, and the vast majority would fall into the latter category, and of the 10% within the secondary TR, they are considered idiopathic, which we'll cover in upcoming slides. So, primary TR includes disorders that affect the trachea survival apparatus, including congenital heart disease, rheumatic fever, endocarditis, radiation, carcinois syndrome, trauma, endocardial biopsy, and intracardial device and leads. By comparison, secondary TR is a result of RV pressure and volume overload from conditions such as pulmonary hypertension, left-sided alveolar disease, myocardial disease, RV volume overload, secondary to intracardial shunts, and an emerging population with atrial fibrillation as the predominant mechanism leading to annular dilatation, and thus secondary TR. Secondary TR frequently manifests as an annular dilatation, where the normal chakras valve annulus, which is usually saddle-shaped and elliptical, becomes flatter and circular, as it dilates in the anterior posterior direction. It may also involve leaflet tethering, and some and unfortunately, sometimes these changes may persist, even after relief of the RV strain. The idiopathic TR, which was briefly alluded to before, comprises of 10% of secondary TR, and this occurs when there's no obvious cause that's identified. However, it appears to be more commonly found in patients who are older and with atrial fibrillation that lead to extreme annular dilatation as a proposed mechanism. In terms of isolated TR management, diuretics are often used to reduce right-heart pressures, but the only definitive treatment for isolated TR is chakras valve surgery. As it stands, isolated TV surgery is rare, and in the US it is estimated around 4,000 to 8,000 chakras valve operations occur per year, which compared to a prevalence of greater than 1.6 million people with moderate or greater TR, this number is very little by comparison. The vast majority of chakras valve operations occur during left-off surgery, leaving about 20% of stand-alone operations, frequently for conditions such as endocarditis. This graph demonstrates that the isolated chakras valve surgical volume highlighted by the red arrow has remained constant throughout the years, despite the overall number of chakras valve cases increasing in blue. And Shonen Yellow demonstrates how most of the increase in the chakras valve surgery occurred as a combined operation during left-off surgery. This graph demonstrates as highlighted by red arrow that most of chakras valve surgery occur as repair. And so chakras valve surgery is rare, and the current trend is to leave isolated TR untreated. And this practice pattern is based on contradictory beliefs stating that severe TR is a benign condition, but isolated chakras valve surgery represents a high-risk operation. Growing evidence in literature suggests that chakras valve agitation is not benign, and that presence of severity of TR increases mortality in cardiovascular events. As a matter of fact, moderate to severe chakras valve agitation may lead to a greater than two-fold increase in cardiovascular mortality, independent of PA pressures, LV function, and RV dysfunction. This graph demonstrates worsening survival with greater TR as highlighted by red arrow showing severe functional chakras valve agitation. There are challenges in chakras valve surgery. For one, the inhospitable mortality for isolated TR surgery has been around 8 to 10 percent in most series, which is a very high number. However, this must be taken into account that a lot of these historical series include a small sample size, and most of these studies spanned over multiple decades. These studies often included heterogeneous populations, often including patients who underwent left valve surgery, who often were candidates undergoing multi-valvular operation with advanced heart failure and redo operations, all of which are known to increase the postoperative mortality. This graph demonstrates that the inhospitable mortality following chakras valve surgery has remained similar, despite increasing overall chakras valve surgical volume over the years, with the red arrow pointing to an average inhospitable mortality of 8.8 percent. And it makes one wonder why we have not been able to make improvements in hospital mortality following chakras valve surgery, despite increasing surgical volume and increasing familiarity with chakras valve operation. Unlike the aeroticket mitral surgery, where the surgical referral is based on an integration of symptoms, disease severity, and markers of LV dysfunction and dilatation, isolated TR has little data to base timing off of chakras valve surgery. As a result, chakras valve surgical mortality may be adversely affected as a result of delayed operative interventions and resultant RV dysfunction and end organ damage. A lot of TR patients present with advanced disease consequently, in the form of CHF, kidney, liver, or RV dysfunction. And it's interesting to know that the Charleston Index, which is a marker of tenure mortality for isolated TR patients, is more than two times that of aerotixtenosis patients during the early days of TAVR. We understand now that chakras valve surgery has consistently shown to improve symptoms. But what remains uncertain is regarding the long-term outcomes after chakras valve operation. In particular, there is very limited information regarding the long-term survival in cases of isolated TR. When comparing medical therapy versus surgery group, there was a prospective propensity-matched study, comprised of secondary TR in 66% of patients with a non-significant trend towards improved survival after surgery. However, more studies are needed in this area. At the moment, the only class 1 indication for chakras valve surgery is at the time of left-sided valve surgery as highlighted in the red box. Chakras valve intervention in other situations remain less clear. Some common chakras valve operative techniques include the K bicuspidization, the vega suture anaeroplasty, band anaeroplasty, and chakras valve replacement. The decision to repair versus replace is largely driven by anatomic factors such as the extent of leaflet damage and the degree of annular dilatation. Most of chakras valve surgery occurs at the time of left valve surgery and most of chakras valve surgery are done as repairs. That valve repair may be preferred, when feasible, to reduce the risk of prosthetic valve thrombosis, bioprosthetic valve degeneration, and long-term anticoagulation. There's a question of whether to use ring anaeroplasty versus the vega anaeroplasty. The residual TR at five years has been shown to be less using a rigid ring at 10 percent versus the vega at 20 to 35 percent. And also, when comparing rigid ring anaeroplasty versus band anaeroplasty, both techniques seem to provide similar freedom from early TR, but rigid ring anaeroplasty has been shown to be associated with ring dehiscence, typically occurring near the chakras valve septal leaflet. And as one can imagine, ring dehiscence is associated with significant greater residual TR. So recurrent 3 plus TR, or more following chakras valve repair, is overall estimated to be 3 to 14 percent in months and up to 20 percent by five years. Some of the risk factors that have been associated with recurrent TR are baseline TR severity, pulmonary hypertension, alve dysfunction, intracardial device, annual dilatation, and leaflet tethering. So these considerations become important from a surgeon's perspective because re-operation for recurrent TR carries a very high mortality, up to 37 percent in the hospital after surgery. When comparing mortality in chakras valve repair versus replacement, they appear to be similar if adjusted for comorbidities. And the decision to proceed between bioprosthetic versus mechanical, thankfully for bioprosthetic valves and chakras valve positions, they appear to be more durable, possibly as a result of lower pressures and velocities. But keeping in mind that the risk of severe bioprosthetic degeneration may be as high as 7 percent at 7 to 80 years. And at this time, overall, there's no definite survival benefit between mechanical versus bioprosthetic valve. So we get to our first case, which is a six-year-old female with wolf parkinson white, status post-EP ablation. She made good recovery post procedure and was asymptomatic. She underwent routine echo, which showed moderate TR, and it was decided to be followed with serial annual echo, which unfortunately showed progressive TR. And by the time of her referral for surgical correction, her preoperative echo showed torrential TR of unclear ideology. She had mild to moderate MR, no palming hypertension, and preserved biventricular function. She was in sinus rhythm without significant coronary artery disease. And this is her preoperative echo. It's a mid esophageal short axis view at 50 degrees. There's a significant TV annular dilatation and the maximal co-optation defect as a result of annular dilatation measures approximately 1.2 centimeters. There's also some tethering of the leaflets as well. Color flow Doppler shows severe TR. This appears somewhat slightly eccentric, secondary to more tethering of the septal leaflet. And on the right video, one can appreciate severe right atrial dilatation. This is a 3D echo demonstrating tracheous valve co-optation defect. So in the OR, this patient was found to have scarred right atrial tissue from previous ablation, very thinned and dilated right atrial wall, leading to severely dilated tracheous valve annulus. So the patient underwent tracheous valve repair in the form of band annular plastic using simplicity band. And this is the echo status post tracheous valve repair. It's a right modified parasternal long axis demonstrating normal leaflet motion status post repair. No significant residual TR. And there's a good viventric killer function and there's no significant trans-vabular gradient, a mean of three and peak of eight. The second case is a 40-year-old male previously healthy, a construction worker, who had a right bundle branch block and had a cardiology workup, was found to have a dilated right ventricle incidentally. And so a follow-up echo was arranged to rule out ASD and no ASD was found, but there was severe isolated tracheuspid regurgitation. And it appeared that the culprit was flail anterior tracheous valve leaflet with a small piece of ruptured anterior papillary muscle with tethered posterior leaflet component. Although there was no documentation of prior chest trauma, given that this patient is involved in construction work with use of heavy machinery at work, there were some concerns that were raised regarding the possibility of trauma component leading to his incidental finding of TR. So this is the preoperative echo in right modified parasternal long axis. One can visualize the tracheous valve septal and anterior leaflets. You can appreciate the anterior leaflet flail. On the right is showing dilated RV NRA with preserved function. By color, there's severity R, which appears eccentric towards the interatural septum, rising from the flail anterior leaflet. And here by transes aphageal echo, we can appreciate severity R by color flow Doppler. There's a flail anterior leaflet with the gap measuring 13 millimeters. There's also some restriction of posterior leaflet that is also generating a secondary jet directed more posteriorly towards the lateral wall of the right atrium. And again the TR jet is shown here. So this patient was taken to the operating room and interoperative inspection demonstrated disrupted anterior papillary muscle. So tracheous valve repair was performed by reattachment of the anterior papillary muscle to the interventricular septum using Gore-Tex suture combined with a ring annular plastic 30 millimeter carpenteria physio. And this is a four-chamber view after tracheous valve repair showing normal tracheous valve leaflet motion without significant residual TR goodbye ventricular function and no significant post repair tracheous valve stenosis with mean of 2 and peak of 4. In conclusion, the majority of isolated TR is functional as much as 80 percent and frequently these are adjusted during left heart surgery. Recent data suggests that despite the overall increase in all tracheous valve surgery volumes there has really been minimal increase in isolated tracheous valve surgery. We do appreciate now better that isolated significant TR is not benign and that it may lead to advanced RV dysfunction and end organ injury and that uncorrected TR for prolonged periods of time may lead to reduced survival. Tracheous valve surgery mortality remains quite high around 8 percent which is much higher than left valve surgery but this must be taken into account the heterogeneous population, the mixed indications and different study eras. Given the paucity of data the interventional criteria in isolated TR remains unclear at this time which frequently leads to delayed surgical referral and unfortunately many patients suffer from RV dysfunction and end organ failure prior to their surgical correction of TR. We are beginning to appreciate more the need for earlier TR correction preferably before the onset of irreversible RV dysfunction and end organ injury and this growing awareness highlights an urgent need for us to develop more objective interventional criteria for tracheous valve surgery. We now understand better that tracheous valve surgery certainly improve symptoms arising from isolated TR. What remains less clear at this time is the long-term survival advantage that may be associated with standalone tracheous valve operation and so more research would be needed in this field to determine the protective effect of tracheous valve surgery and how it may alter the natural history of isolated TR. Thank you.