Turbulent blood dynamics in the left heart in the presence of mitral regurgitation: a computational study based on multi-series cine-MRI.

In this work, we performed a computational image-based study of blood dynamics in the whole left heart, both in a healthy subject and in a patient with mitral valve regurgitation. We elaborated multi-series cine-MRI with the aim of reconstructing the geometry and the corresponding motion of left ventricle, left atrium, mitral and aortic valves, and aortic root of the subjects. This allowed us to prescribe such motion to computational blood dynamics simulations where, for the first time, the whole left heart motion of the subject is considered, allowing us to obtain reliable subject-specific information. The final aim is to investigate and compare between the subjects the occurrence of turbulence and the risk of hemolysis and of thrombi formation. In particular, we modeled blood with the Navier-Stokes equations in the arbitrary Lagrangian-Eulerian framework, with a large eddy simulation model to describe the transition to turbulence and a resistive method to manage the valve dynamics, and we used a finite element discretization implemented in an in-house code for the numerical solution.

An Image-Based Computational Fluid Dynamics Study of Mitral Regurgitation in Presence of Prolapse.

PURPOSE: In this work we performed an imaged-based computational study of the systolic fluid dynamics in presence of mitral valve regurgitation (MVR). In particular, we compared healthy and different regurgitant scenarios with the aim of quantifying different hemodynamic quantities. METHODS: We performed computational fluid dynamic (CFD) simulations in the left ventricle, left atrium and aortic root, with a resistive immersed method, a turbulence model, and with imposed systolic wall motion reconstructed from Cine-MRI images, which allowed us to segment also the mitral valve. For the regurgitant scenarios we considered an increase of the heart rate and a dilation of the left ventricle. RESULTS: Our results highlighted that MVR gave rise to regurgitant jets through the mitral orifice impinging against the atrial walls and scratching against the mitral valve leading to high values of wall shear stresses (WSSs) with respect to the healthy case. CONCLUSION: CFD with prescribed wall motion and immersed mitral valve revealed to be an effective tool to quantitatively describe hemodynamics in case of MVR and to compare different regurgitant scenarios. Our findings highlighted in particular the presence of transition to turbulence in the atrium and allowed us to quantify some important cardiac indices such as cardiac output and WSS.

Urgent Surgery for Pituitary Adenoma Bleeding After Coronary Bypass Surgery.

Pituitary gland adenoma bleeding is an uncommon complication after coronary artery surgery. Clinical presentation may be variable. We report a case of hemorrhagic complication of a pituitary gland adenoma requiring urgent surgery in a 60-year-old male patient who underwent coronary artery bypass grafting operation.

Hybrid Coronary Revascularization Versus Off-Pump Coronary Artery Bypass Grafting: Comparative Effectiveness Analysis With Long-Term Follow-up.

Background Hybrid coronary revascularization (HCR) involves the integration of coronary artery bypass grafting (CABG) and percutaneous coronary intervention to treat multivessel coronary artery disease. Our objective was to perform a comparative analysis with long-term follow-up between HCR and conventional off-pump CABG. Methods and Results We compared all double off-pump CABG (n=216) and HCR (n=147; robotic-assisted minimally invasive direct CABG of the left internal thoracic artery to the left anterior descending artery and percutaneous coronary intervention to one of the non-left anterior descending vessels) performed at a single institution between March 2004 and November 2015. To adjust for the selection bias of receiving either off-pump CABG or HCR, we performed a propensity score analysis using inverse-probability weighting. Both groups had similar results in terms of re-exploration for bleeding, perioperative myocardial infarction, stroke, blood transfusion, in-hospital mortality, and intensive care unit length of stay. HCR was associated with a higher in-hospital reintervention rate (CABG 0% versus HCR 3.4%; P=0.03), lower prolonged mechanical ventilation (>24 hours) rate (4% versus 0.7%; P=0.02), and shorter hospital length of stay (8.1±5.8  versus 4.5±2.1 days; P<0.001). After a median follow-up of 81 (48-113) months for the off-pump CABG and 96 (53-115) months for HCR, the HCR group of patients had a trend toward improved survival (85% versus 96%; P=0.054). Freedom from any form of revascularization was similar between the 2 groups (92% versus 91%; P=0.80). Freedom from angina was better in the HCR group (73% versus 90%; P<0.001). Conclusions HCR seems to provide, in selected patients, a shorter postoperative recovery, with similar excellent short- and long-term outcomes when compared with standard off-pump CABG.

Total Endovascular Aortic Arch Repair with Branched Graft.

In selected cases, the utilization of branched endografts for the treatment of aortic arch aneurysms could be a safe and advantageous alternative to high-risk procedures such as open total aortic arch replacement or hybrid arch repair. We present the case of a 70-year-old man with saccular aneurysm of a bovine aortic arch which was endovascularly treated using a double-branched custom-made aortic endoprosthesis based on the Relay NBS (Non-Bare Stent) Plus platform intended for zone 0 deployment. The postoperative clinical course was uneventful. The postoperative computed tomography scan showed a good result of the implant. The patient was discharged 6 days after the procedure.

Hybrid Coronary Revascularization Versus On-Pump Coronary Artery Bypass Grafting.

BACKGROUND: Hybrid coronary revascularization (HCR) is an evolving coronary revascularization strategy for the treatment of multivessel coronary artery disease. We provide a comparative analysis to conventional on-pump coronary artery bypass graft surgery (CABG) with long-term follow-up. METHODS: We included all double on-pump CABG (n = 682) and HCR (147 robotic-assisted minimally invasive bypass grafts of the left internal thoracic artery to the left anterior descending coronary artery and percutaneous coronary intervention to one of the non-left anterior descending coronary artery vessels) performed in our institution between March 2004 and November 2015. We performed an adjusted analysis using inverse-probability weighting based on the propensity score of receiving either on-pump CABG or HCR. RESULTS: In the adjusted analysis, there was no statistically significant difference in the incidence of reexploration for bleeding, perioperative myocardial infarction, stroke, need for hemodialysis, blood transfusion rate, prolonged mechanical ventilation, and intensive care unit length of stay. Hybrid coronary revascularization was associated with lower inhospital mortality (CABG 1.3%, HCR 0%, p = 0.008), and shorter mean (± SD) hospital length of stay (CABG 6.7 ± 4.7 days, HCR 4.5 ± 2.1 days, p < 0.001). After a median follow-up period of 70 months (range, 37 to 106) for the CABG group and 96 months (range, 53 to 114) for the HCR group, there was no significant difference in survival (CABG 92%, HCR 97%, p = 0.13) or freedom from any form of revascularization (CABG 93%, HCR 91%, p = 0.27). Hybrid coronary revascularization was superior in freedom from angina (CABG 70%, HCR 91%, p < 0.001). CONCLUSIONS: For selected patients, HCR is associated with a faster postoperative recovery as well as similar short-term and long-term outcomes when compared with standard on-pump CABG.

Robotic-assisted coronary artery bypass surgery: an 18-year single-centre experience.

BACKGROUND: Minimally invasive robot-assisted direct coronary artery bypass (RADCAB) has emerged as a feasible minimally invasive surgical technique for revascularization that might offer several potential advantages over conventional approaches. We present our 18-year experience in RADCAB. METHODS: Between February 1998 and February 2016, 605 patients underwent RADCAB. Patients underwent post-procedural selective graft patency assessment using cardiac catheterization. RESULTS: The mortality rate was 0.3%. The rate of conversion to sternotomy for any cause was reduced from 16.0% of the first 200 cases to 6.9% of the last 405 patients. The patency rate of the LITA-to-LAD anastomosis was 97.4%. Surgical re-exploration for bleeding occurred in 1.8% of patients, and the transfusion rate was 9.2%. Average ICU stay was 1.2 ± 1.4 days, and average hospital stay was 4.8 ± 2.9 days. CONCLUSIONS: Robot-assisted coronary artery bypass grafting is safe, feasible and it seems to represent an effective alternative to traditional coronary artery bypass grafting in selected patients.

Is the Future of Coronary Arterial Revascularization a Hybrid Approach?: The Canadian Experience Across Three Centers.

OBJECTIVE: Hybrid coronary revascularization offers and combines the advantages of both surgical and percutaneous revascularization and eliminates at the same time the disadvantages of both procedures. The objective of this study was to assess graft and stent patency at 6 months, rate of bleeding, intensive care unit and hospital stay, rate of reintervention, and long-term clinical follow-up. METHODS: From March 2004 to November 2015, a total of 203 patients underwent robotic-assisted minimally invasive direct coronary artery bypass graft of the left internal thoracic artery to the left anterior descending artery and PCI of a non-left anterior descending vessel in a single or two stage, at three different centers. Patients underwent 6-month angiographic follow-up. The mean ± SD clinical follow-up was 77.82 ± 41.4 months. RESULTS: Successful hybrid coronary revascularization occurred in 196 of the 203 patients. One hundred forty-six patients underwent simultaneous surgical and percutaneous intervention. Nineteen patients underwent PCI before surgery, and 38 patient underwent PCI after surgery. No in-hospital mortality occurred. The mean ± SD ICU stay was 1 ± 1 days and the mean ± SD hospital stay was 5 ± 2 days. Only 13.3% of the patients required a blood transfusion. Six-month angiographic follow-up has been performed in the 95 patients, and it demonstrated a left internal thoracic artery anastomotic patency of 97.9% and stent patency of 92.6%. A total of 77.8 ± 41.4-month clinical follow-up demonstrated 95.1% survival, 92.6% freedom from angina, and 90.7% freedom from any form of coronary revascularization. CONCLUSIONS: Hybrid coronary revascularization seems to be a promising and safe revascularization strategy. It provides selected patients with an alternative, functionally complete revascularization with minimal surgical trauma and good long-term clinical outcomes.

Consequences of Hybrid Procedure Addition to Robotic-Assisted Direct Coronary Artery Bypass.

OBJECTIVE: Patients postcoronary artery revascularization surgery often receives blood product transfusion, which could delay their intensive care unit and hospital discharge. We investigated our robotic-assisted direct coronary artery bypass (RADCAB) transfusion rate to determine whether performing the minimal invasive coronary surgery with percutaneous coronary intervention in one stage would increase the incidence of blood transfusion, morbidity, and length of stay. METHODS: Between November 2003 and November 2015, 483 consecutive patients underwent RADCAB surgery. They were divided into two groups. Group 1 (147 patients; mean ± SD age, 61.2 ± 11 years; 23% females) underwent robotic-assisted hybrid coronary artery revascularization with left internal thoracic artery to the left anterior descending coronary artery with percutaneous coronary intervention to a nonleft anterior descending coronary artery vessel in the same stage. Group 2 (336 patients; mean ± SD age, 61.2 ± 10.5 years; 25% females) underwent nonhybrid RADCAB. Early and late postoperative follow-up at mean ± SD of 83.6 ± 11.1 months was obtained. RESULTS: Blood transfusion rate in group 1 was statistically different, as illustrated in Table 2. Based on the intraoperative cardiac catheterization, the incidence of graft revision was higher in the nonhybrid group. There was no difference between the two groups in terms of renal failure, neurological complication, prolonged mechanical ventilation, and gastrointestinal bleed. CONCLUSIONS: Despite similar preoperative demographics in the two groups, we have observed a significant difference in the blood transfusion rate in group 1. However, this did not lead into a statistically significant re-exploration rate for bleeding. Hence, we assume that dual antiplatelet therapy usage in the hybrid group might be the cause of the increase in blood transfusion rate. Nevertheless, it did not affect postoperative morbidity and length of hospital stay. A randomized multicenter clinical trial is needed.

Alternative Surgical Approach to Repairing a Giant Sinus of Valsalva Aneurysm.

We report our method of surgically repairing an unruptured giant aneurysm of the right coronary sinus of Valsalva, a lesion that caused moderate aortic regurgitation but no symptoms in a 61-year-old woman. We excised the aneurysm, reconstructed the right sinus of Valsalva with use of a patch, performed mechanical aortic valve replacement directly through the excised aneurysm's cavity, and constructed a single bypass graft to the right coronary artery. The patient was discharged from the hospital after 5 days. Twelve months postoperatively, her clinical and echocardiographic results were normal, and she was doing well. To our knowledge, our surgical approach to this repair has not been described previously.