Metabolic changes contribute to maladaptive right ventricular hypertrophy in pulmonary hypertension beyond pressure overload: an integrative imaging and omics investigation.

Right ventricular (RV) failure remains the strongest determinant of survival in pulmonary hypertension (PH). We aimed to identify relevant mechanisms, beyond pressure overload, associated with maladaptive RV hypertrophy in PH. To separate the effect of pressure overload from other potential mechanisms, we developed in pigs two experimental models of PH (M1, by pulmonary vein banding and M2, by aorto-pulmonary shunting) and compared them with a model of pure pressure overload (M3, pulmonary artery banding) and a sham-operated group. Animals were assessed at 1 and 8 months by right heart catheterization, cardiac magnetic resonance and blood sampling, and myocardial tissue was analyzed. Plasma unbiased proteomic and metabolomic data were compared among groups and integrated by an interaction network analysis. A total of 33 pigs completed follow-up (M1, n = 8; M2, n = 6; M3, n = 10; and M0, n = 9). M1 and M2 animals developed PH and reduced RV systolic function, whereas animals in M3 showed increased RV systolic pressure but maintained normal function. Significant plasma arginine and histidine deficiency and complement system activation were observed in both PH models (M1&M2), with additional alterations to taurine and purine pathways in M2. Changes in lipid metabolism were very remarkable, particularly the elevation of free fatty acids in M2. In the integrative analysis, arginine-histidine-purines deficiency, complement activation, and fatty acid accumulation were significantly associated with maladaptive RV hypertrophy. Our study integrating imaging and omics in large-animal experimental models demonstrates that, beyond pressure overload, metabolic alterations play a relevant role in RV dysfunction in PH.

Root-commando operation with a modified self-assembled aortic root conduit for endocarditis after sutureless aortic valve replacement.

We present a case of a Staphylococcus epidermidis early prosthetic valve endocarditis after minimally invasive sutureless aortic valve replacement. The patient developed a root abscess with a fistula, severe mitral and periprosthetic regurgitations, with a large mitral vegetation and a residual patent foramen ovale. The surgical approach consisted of a redo median sternotomy, explantation of a sutureless aortic prosthesis, resection of an intervalvular fibrosa and anterior mitral leaflet and debridement of an aortic root-left ventricle outflow tract abscess. These procedures were followed by a root-commando procedure with mitral and aortic root placement using a self-assembled mechanical aortic root conduit. The technique used is an alternative to a root-commando procedure performed with an allograft or a Medtronic Freestyle bioprosthesis. The same technique can be utilized with a commercially available stented bioprosthesis.

Repair of mitral prolapse: comparison of thoracoscopic minimally invasive and conventional approaches.

OBJECTIVES: Surgical repair remains the best treatment for severe primary mitral regurgitation (MR). Minimally invasive mitral valve surgery is being increasingly performed, but there is a lack of solid evidence comparing thoracoscopic with conventional surgery. Our objective was to compare outcomes of both approaches for repair of leaflet prolapse. METHODS: All consecutive patients undergoing surgery for severe MR due to mitral prolapse from 2012 to 2020 were evaluated according to the approach used. Freedom from mortality, reoperation and recurrent severe MR were evaluated by Kaplan-Meier method. Differences in baseline characteristics were adjusted with propensity score-matched analysis (1:1, nearest neighbour). RESULTS: Three hundred patients met inclusion criteria and were divided into thoracoscopic (N = 188) and conventional (sternotomy; N = 112) groups. Unmatched patients in the thoracoscopic group were younger and had lower body mass index, New York Heart Association class and EuroSCORE II preoperatively. After matching, thoracoscopic group presented significantly shorter mechanical ventilation (9 vs 15 h), shorter intensive care unit stay (41 vs 65 h) and higher postoperative haemoglobin levels (11 vs 10.2 mg/dl) despite longer bypass and cross-clamp times (+30 and +17 min). There were no differences in mortality or MR grade at discharge between groups nor differences in survival, repair failures and reinterventions during follow-up. CONCLUSIONS: Minimally invasive mitral repair can be performed in the majority of patients with mitral prolapse, without compromising outcomes, repair rate or durability, while providing shorter mechanical ventilation and intensive care unit stay and less blood loss.

Difficult ventilation in a patient with a giant aortic aneurysm: A challenge for the anesthesiologist.

Patients with Marfan syndrome present anatomic variations that may increase the risk of a difficult airway. Moreover, they can present large aortic aneurysms, which may cause extrinsic airway compression. Therefore, difficult ventilation during general anesthesia poses a challenge in that the anesthesiologist has to promptly make a crucial differential diagnosis. Multidisciplinary preoperative assessment and planning of the airway and ventilation management are of utmost importance in such uncommon and highly complex clinical cases. Fiberoptic bronchoscopy is probably a really useful tool in order to assess the severity and extent of the airway compression, both preoperatively and intraoperatively. We present a clinical case where difficult ventilation occurred immediately after the induction of general anesthesia.

Closure of Left Atrial Appendage Has no Effect on Thromboembolic Rates after Mitral Valve Repair in Patients in Sinus Rhythm.

Closure of the left atrial appendage (LAA) reduces the rates of TIA/stroke in patients in atrial fibrillation (AF) but its role in patients in sinus rhythm who undergo mitral valve repair (MV) for leaflet prolapse remains unknown. This study examined the effects of closing the LAA in TIA/stroke after MV repair. Our database on patients who had MV repair for leaflet prolapse from 2000 through 2019 was reviewed. After excluding patients at higher risk of TIA/stroke, 1050 patients in sinus rhythm were entered into the study: 781 with open LAA and 269 with surgically closed LAA. Using a propensity score analysis to compensate from clinical differences, 267 pairs of patients with open and closed LAA were matched. Follow-up was truncated at 5 years because routine closure of the LAA was performed only during recent years. The cumulative incidence of TIA/stroke at 5 years in the entire cohort was 2.7% [95% CI 1.9, 4.0]; it was 2.9% [95% CI 1.9, 4.4] in patients with open LAA,and 1.8% [95% CI 0.7, 4.9] in patients with closed LAA (P = 0.53). In the matched cohorts, the cumulative incidences of TIA/stroke did not differ significantly (match-adjusted HR [95% CI] = 0.80 [0.21, 2.98], P = 0.74), and multivariable Cox proportional hazard regression analysis also confirmed no difference in the risk of TIA/stroke between the 2 groups (regression-adjusted HR [95% CI] = 0.58 [0.12, 2.9], P = 0.47). This study failed to show a reduction in the risk of TIA/stroke by closing the LAA in patients in sinus rhythm (Figure 6). Closure of the LAA during MV repair warrants a larger and more rigorous study.

In-hospital thromboembolic complications after frozen elephant trunk aortic arch repair.

OBJECTIVE: This study evaluated the frequency and clinical impact of thromboembolic complications after frozen elephant trunk aortic arch repair using the Thoraflex device (Terumo Aortic). METHODS: A total of 128 consecutive patients (mean age 67.9 ± 13.7 years, 31.0% female) underwent frozen elephant trunk aortic arch repair using the Thoraflex device between September 2014 and May 2021 in 4 Canadian centers. Patient baseline characteristics, intraoperative details, and frozen elephant trunk thromboembolic complications were collected retrospectively and analyzed. RESULTS: Fifteen patients (11.7%) had thrombus visualized within the frozen elephant trunk stent graft on imaging (n = 8; 53.3%) or had a thromboembolic event (n = 9; 60.0%) before hospital discharge. Sites of embolism were mesenteric (n = 8; 88.9%), renal (n = 4; 44.4%), and iliofemoral (n = 1; 11.1%). Patients who experienced thromboembolic complications were more likely to have a history of autoimmune disease (n = 3; 20.0% vs n = 2; 1.8%; P = .01) and implantation of a longer frozen elephant trunk stent graft (150 mm vs 100 mm) (n = 13; 86.7% vs n = 45; 39.8%; P < .001). All patients with thromboembolic complications received therapeutic anticoagulation, and a smaller proportion required an open surgical (n = 5; 33.3%) or an endovascular (n = 2; 13.3%) intervention. Radiographic resolution of thromboembolic complications was observed in 86.7% of patients (n = 13). In-hospital mortality occurred in 1 patient, stroke occurred in 1 patient, and transient spinal cord injury occurred in 1 patient. CONCLUSIONS: Thromboembolic complications occur more often than previously recognized after frozen elephant trunk aortic arch repair using the Thoraflex device and are associated with increased rates of surgical and endovascular reintervention. Prevention and management of these complications require further study.

Open descending thoracic aorta aneurysm repair with removal of multiple previous endovascular devices.

False lumen patency is a poor prognostic factor for favorable aortic remodeling in patients with chronic aortic dissection. Several endovascular techniques are available to obliterate the false lumen; however, they are not always successful. We present the case of a 55-year old male with a chronic type B dissection and a large descending thoracic aortic aneurysm with rapid growth, up to 90 mm, despite attempted control of the false lumen with several endovascular devices (thoracic aortic stent graft, Amplatzer device, glue and candy plug). Successful aneurysmal open repair was achieved by removing these devices during the procedure. This case demonstrates the technical challenges of explanting an aortic stent graft and multiple other devices during distal aortic repair.

Infective endocarditis of a native quadricuspid aortic valve.

Quadricuspid aortic valve complicated with infective endocarditis is an uncommon clinical scenario. The indications for surgery and medical management do not differ from other types of aortic valve endocarditis. Commonly present structural abnormalities pose an increased risk of complete heart block and coronary occlusion during valve replacement. We present a case of quadricuspid aortic valve complicated with infective endocarditis, with surgical images of the valve.

Postinfarction posterior ventricular septal defect repair: Infarct exclusion technique.

A 61-year-old man, an active smoker with associated chronic obstructive pulmonary disease on bronchodilator therapy, presented with acute inferior ST-elevation myocardial infarction. The right coronary artery was shown to be the infarct-related artery and was ultimately treated with a drug-eluting stent with an optimal angiographic result. Despite treatment, the patient continued to experience chest pain. Echocardiography showed an extensive posterior mid-ventricular septal defect. Given the scenario of an acute ventricular septal defect with impending hemodynamic repercussions, emergency surgery was pursued. After a median sternotomy and institution of cardiopulmonary bypass with bicaval cannulation, the inferior wall was exposed to assess the necrotic scar. After ventriculotomy, there was an irregular large septal defect with poorly defined margins. In this case, the posterior papillary muscle showed patchy areas of necrosis, requiring a mitral valve replacement. The ventricular septal defect was repaired using an oval-shaped bovine pericardial patch sutured with 3-0 polypropylene sutures, secured with Teflon pledgets, placed transmurally in healthy endocardium. The same patch was incorporated in the ventriculotomy closure.

Direct true lumen cannulation for type A aortic dissection (Samurai technique) in emergency scenarios.

Choosing the optimal arterial cannulation site in type A aortic dissection may be challenging. Aortic dissection is a dynamic condition that can change at any time. Thus all the alternatives available should be known by surgeons in order to adapt to the possible problems that may arise. In this video tutorial, we present a patient with acute type A aortic dissection who, after cardiopulmonary bypass with axillary arterial cannulation, developed a major complication: intraoperative malperfusion due to pressurization of the false lumen. The patient developed occlusion of the right coronary artery with electrocardiogram changes, inferior akinesia, and ventricular arrhythmias. Cerebral saturation was also significantly decreased. This scenario of acute malperfusion calls for immediate action.  We proceeded to switch the cardiopulmonary bypass configuration from axillary to direct true lumen cannulation. This technique, also known as the Samurai technique, is feasible in most cases and advantageous in this emergency situation, allowing prompt reestablishment of adequate perfusion of the true lumen . Some authors even advocate more widespread use of this technique because it may ensure antegrade perfusion while avoiding progression of the dissection flap and reduce the rate of the most common complications of other cannulation sites such as plexus injury during axillary cannulation or cerebral embolization through mobilization of thrombi or calcification from femoral retrograde perfusion. This technique is useful in cases of circumferential dissection and in patients with relative contraindications for peripheral cannulation such as morbid obesity or peripheral arterial occlusion by atherosclerosis or by the dissection itself.

Extended septal myectomy and left ventricular outflow tract intervention for hypertrophic obstructive cardiomyopathy.

Hypertrophic obstructive cardiomyopathy is the most common inherited cardiomyopathy. Septal myectomy is a low-risk operation and remains the first septal reduction therapeutic option. We present a patient with hypertrophic obstructive cardiomyopathy requiring extended septal myectomy and concomitant left ventricular outflow tract intervention. In addition to septal reduction therapy, this patient also underwent anterior mitral valve plication, trigonal release, and secondary chordal division to relieve the obstruction. A tailored approach to hypertrophic obstructive cardiomyopathy with a comprehensive left ventricular outflow tract intervention is necessary to ensure the best hemodynamic outcome. Preoperative heart failure and recurrent syncope fully resolved after this intervention.

Operative management of ascending aorta thrombus and bilateral pulmonary embolism in the setting of breast cancer.

Pulmonary embolism (PE) and concomitant floating aortic thrombus are a rare and potentially life-threatening association. Several therapeutic options are available and best management can be controversial when these conditions coexist. We describe a case of a 79-year-old woman presented with massive PE and simultaneous floating thrombus in the ascending aorta. She underwent concomitant ascending aortic replacement and surgical pulmonary embolectomy with an uneventful postoperative recovery. Open surgical repair is a one stage approach that may offer the most efficient treatment to allow survival.

Effect of sildenafil on right ventricular performance in an experimental large-animal model of postcapillary pulmonary hypertension.

Right ventricle (RV) dysfunction is a main determinant of morbidity and mortality in postcapillary pulmonary hypertension (PH). However, currently there are not available therapies. Since reduced nitric oxide (NO) availability and cyclic guanylate monophosphate (cGMP) levels are central in this disease, therapies targeting the NO pathway might have a beneficial effect on RV performance. In this regard, sildenafil has shown contradictory results. Our objective was to evaluate the effect of sildenafil on RV performance in an experimental pig model of postcapillary PH induced by a fixed banding of the venous pulmonary confluent. Animals were evaluated by right heart catheterization and cardiac magnetic resonance before randomization and after 8 weeks on sildenafil (n = 8) or placebo (n = 8), and myocardial tissues were analyzed with histology and molecular biology. At the end of the study, animals receiving sildenafil showed better RV performance as compared with those on placebo (improvement in RV ejection fraction of 7.3% ± 5.8% versus -0.6% ± 5.0%, P= 0.021) associated with less apoptotic cells and gene expression related with reduced oxidative stress and increased anti-inflammatory activity in the myocardium. No differences were observed in pulmonary hemodynamics. In conclusion, in a translational large animal model of chronic postcapillary PH, sildenafil improved RV systolic function independently of afterload. Further research with pharmacological approaches able to manipulate the NO-cGMP axis are needed to confirm this potential cardioprotective effect.

Root-commando operation for multivalvular endocarditis and pericardiectomy.

This video tutorial  presents the reconstruction of the intervalvular fibrosa and a triple valve replacement, due to prosthetic valve endocarditis, in a patient with previous chest irradiation and bicuspid aortic valve replacement. Constrictive pericarditis was also present since the original operation. A detailed step-by-step demonstration of the reconstruction of the intervalvular fibrosa and debridement of extensive prosthetic valve endocarditis with paravalvular root abscess are provided.  A secondary sternotomy was performed and, in the process, the ascending aorta was injured, with associated life-threatening bleeding. Manual compression was applied while peripheral cannulation and cardiopulmonary bypass were started. The bleeding was controlled with cooling and circulatory arrest and the ascending aorta was replaced with a Dacron graft. The intervalvular fibrosa was reconstructed using a folded pericardial patch.  Aortic root replacement with a cryopreserved homograft was performed and the mitral and tricuspid valves were replaced with tissue valve prostheses. A complete pericardiectomy was performed. The chest was left packed with cotton due to diffuse bleeding. At the time of the delayed chest closure, a permanent epicardial pacemaker was implanted.

Cone repair for Ebstein's anomaly and atrial fibrillation ablation in an adult patient.

We present a 52-year-old woman with Ebstein's anomaly not previously treated. In this subset of patients, there are no clear guidelines regarding the best surgical strategy for treating the tricuspid valve: replace it or repair it.  In this case, extensive repair of the tricuspid valve and the right ventricle is achieved using the cone repair technique popularized by Dr. José Pedro Da Silva. Because the patient also presented with symptomatic paroxysmal atrial fibrillation, a right atrial maze procedure combined with isolation of the pulmonary veins was performed using both radiofrequency and cryotherapy. At the last follow-up, 2 years after the repair, the patient is asymptomatic and maintains sinus rhythm. The last echocardiogram showed mild tricuspid regurgitation with normal right ventricular function.