Management of left subclavian artery in type B aortic dissection treated with thoracic endovascular aorta repair.

OBJECTIVE: Thoracic endovascular aortic repair (TEVAR) has been the favored approach for the treatment of type B aortic dissection (TBAD). To obtain an adequate proximal landing zone, coverage of the left subclavian artery (LSA) will often be necessary. The occurrence of possible neurologic complications has continued to be debated. We investigated the management of the LSA in patients with TBAD undergoing endovascular repair. METHODS: We searched the PubMed and MEDLINE databases to October 2020 for studies of TEVAR for TBAD. Data on the study design, demographics, endograft details, LSA coverage and revascularization, mortality, complications, and follow-up were extracted and analyzed. The effects of LSA coverage and revascularization on neurologic complications and outcomes were investigated. RESULTS: A total of 26 reports (24 retrospective and 2 prospective) were deemed eligible for our study. A total of 1483 patients (mean age, 56.9 ± 6.2 years) had undergone TEVAR for acute (n = 932; 62.9%), subacute (n = 36; 2.4%), or chronic (n = 515; 34.7%) TBAD, with a success rate of 97.8% and hospital mortality of 4.9%. The LSA origin had been covered for 707 patients (47.7%), and 326 had undergone LSA revascularization (surgical, n = 96; endovascular, n = 170; unspecified or not reported, n = 60). LSA revascularization was concomitant for 68.1% of cases, after TEVAR for 1.8%, and not reported for 30.1%. Of 1146 patients, 10 (0.9%) had experienced left arm claudication, and the overall stroke rate was 3.3% (2.7% for the LSA group and 1% for the uncovered LSA group; P = .0815). Of the patients with stroke and a covered LSA, 1% (2 of 203) had undergone LSA revascularization and 4.8% (5 of 105) had not (P = .0478). Twenty-six patients (1.9%) had developed paraplegia: 0.7% (3 of 433) with a covered LSA, 1.4% (7 of 491) with an uncovered LSA (P = .3508), and not reported for 16 patients. Endoleak was present in 138 patients (13.4%) at a mean follow-up of 32.1 ± 25.6 months. CONCLUSIONS: Our review has shown that LSA coverage during endovascular repair for complicated TBAD will does not significantly increase the risk of neurologic complications; however, revascularization of the LSA should be always recommended.

Five-Year Survival of Patients Treated with Minimally Invasive Direct Coronary Artery Bypass (MIDCAB) Compared with the General Swiss Population.

BACKGROUND: To evaluate the midterm follow-up and 5-year survival outcome of the minimally invasive direct coronary artery bypass (MIDCAB) procedure compared with the survival of the general Swiss population. METHODS: Retrospective study on preoperative data, intraoperative data, and postoperative outcome of patients who underwent MIDCAB surgery between June 2010 and February 2019. To assess validity of this surgical therapy, outcomes were compared with survival data of a gender- and age-matched cohort of the general Swiss population taken from the database of the Swiss Federal Statistical Office. RESULTS: A total of 88 patients were included. Median (interquartile range [IQR[) age was 66 (56-75) years, and 27% (n = 24) were female. The median (IQR) length of the in-hospital stay was 7 (6-8) days. No postoperative stroke occurred. The 30-day mortality was 1.1% (n = 1). Reintervention for failed left internal mammary artery was needed in 1.1% (n = 1). The median (IQR) ejection fraction was 58% (47-60) preoperatively and remained stable during follow-up. The median (IQR) follow-up period was 3 (1.1-5.2) years. Five years postoperatively, 83% (confidence interval, 69-91) of the patients were alive, showing an overlap with the range of survival of the matched subcohort of the general Swiss population (range, 84-100%). CONCLUSION: Though suffering from coronary heart disease, patients after MIDCAB show almost equal survival rates as an equivalent subcohort corresponding to the general Swiss population matched on age and gender. Thus, our data show this treatment to be safe and beneficial.

Outcome of right ventricular assist device implantation following left ventricular assist device implantation: Systematic review and meta-analysis.

OBJECTIVES: The main aim was a systematic evaluation of the current evidence on outcomes for patients undergoing right ventricular assist device (RVAD) implantation following left ventricular assist device (LVAD) implantation. METHODS: This systematic review was registered on PROSPERO (CRD42019130131). Reports evaluating in-hospital as well as follow-up outcome in LVAD and LVAD/RVAD implantation were identified through Ovid Medline, Web of Science and EMBASE. The primary endpoint was mortality at the hospital stay and at follow-up. Pooled incidence of defined endpoints was calculated by using random effects models. RESULTS: A total of 35 retrospective studies that included 3260 patients were analyzed. 30 days mortality was in favour of isolated LVAD implantation 6.74% (1.98-11.5%) versus 31.9% (19.78-44.02%) p = 0.001 in LVAD with temporary need for RVAD. During the hospital stay the incidence of major bleeding was 18.7% (18.2-19.4%) versus 40.0% (36.3-48.8%) and stroke rate was 5.6% (5.4-5.8%) versus 20.9% (16.8-28.3%) and was in favour of isolated LVAD implantation. Mortality reported at short-term as well at long-term was 19.66% (CI 15.73-23.59%) and 33.90% (CI 8.84-59.96%) in LVAD respectively versus 45.35% (CI 35.31-55.4%) p ⩽ 0.001 and 48.23% (CI 16.01-80.45%) p = 0.686 in LVAD/RVAD group respectively. CONCLUSION: Implantation of a temporary RVAD is allied with a worse outcome during the primary hospitalization and at follow-up. Compared to isolated LVAD support, biventricular mechanical circulatory support leads to an elevated mortality and higher incidence of adverse events such as bleeding and stroke.

Performance characteristics of the new Eurosets magnetically suspended centrifugal pump.

OBJECTIVE: The aim was to evaluate the performance of a newly developed magnetically suspended centrifugal pump head intended for use as a ventricular assistance device with a newly developed extracorporeal membrane oxygenator setup. METHODS: In an experimental setup, an extracorporeal membrane oxygenator circuit was established in three calves with a mean weight of 68.2 ± 2.0 kg. A magnetically levitated centrifugal pump was tested, along with a newly designed extracorporeal membrane oxygenator console, at three different flow ranges: (a) 0.0 to 5.2 L/min, (b) 0.0 to 7.1 L/min, and (c) 0.0 to 6.0 L/min. For each setup, the animals were supported by a circuit for 6 h. Blood samples were collected just before caridiopulmonary bypass (CPB) after 10 min on bypass and after 1, 2, 5, and 6 h of perfusion for hemolysis determination and biochemical tests. Values were recorded for blood pressure, mean flow, and pump rotational speed. Analysis of variance was used for repeated measurements. RESULTS: Mean pump flows achieved during the three 6 h pump runs for the three pump heads studied were as follows: (a) flow range 0.0 to 5.2 L/min, 3.6 ± 1.5 L/min, (b) flow range 0.0 to 7.1 L/min, 4.9 ± 1.3 L/min, and (c) flow range 0.0 to 6.0 L/min, 3.8 ± 1.5 L/min. Blood trauma, evaluated by plasma hemoglobin and lactate dehydrogenase levels, did not help in detecting any significant hemolysis. Thrombocytes and white blood cell count profiles showed no significant differences between the groups at the end of the 6 h perfusion. At the end of testing, no clot deposition was found in the oxygenator, and there was no evidence of peripheral emboli. CONCLUSION: The results suggest that the newly developed magnetically suspended centrifugal pump head provides satisfactory hydrodynamic performance in an acute perfusion scenario without increasing hemolysis.

Echocardiographic and Clinical Follow-up After Aortic Valve Neocuspidization Using Autologous Pericardium.

INTRODUCTION: Mid-term data from a single centre showed the safety and durability of aortic valve neocuspidization using autologous pericardium (OZAKI procedure). Since validation data from other centres are missing, aim of this study was to analyze echocardiographic and clinical results of our first patients that were operated with the OZAKI technique. METHODS: Thirty-five patients (24 males, median (IQR) age 72.0 (59.0, 76.0) years) with aortic stenosis (AS; n = 10), aortic insufficiency (AR; n = 13) or a combination of both (AS/AR; n = 12), underwent aortic valve neocuspidization in our institution between September 2015 and May 2017. Echocardiographic follow-up was performed using a standardized examination protocol. RESULTS: Clinical follow-up was completed in 97% of the patients. Median (IQR) follow-up time was 645 (430, 813) days. Mortality rate was 9% (n = 1: aspiration pneumonia; n = 1: unknown; n = 1: anaphylactic shock), and the reoperation rate was 3% (n = 1: endocarditis). No pacemaker implantation was necessary after isolated OZAKI procedures. Echocardiographic follow-up was performed in 83% of the patients (n = 29; median (IQR) time 664 (497, 815) days). Median (IQR) mean and peak gradients were 6 (5,9) mmHg and 12 (8, 17) mmHg. Moderate aortic regurgitation was seen in 2 patients (7%). No severe aortic regurgitation or moderate or severe aortic stenosis occurred within the follow-up period. CONCLUSIONS: The OZAKI procedure is reliable and reoperation due to structural valve deterioration nil within a median 645 days follow-up period. The low rate of moderate aortic regurgitation will be surveilled very closely. Further studies are required to evaluate the significance of this procedure in aortic valve surgery. CLINICAL REGISTRATION NUMBER: ClinicalTrials.gov (ID NCT03677804).

Impact of Modified Frozen Elephant Trunk Procedure on Downstream Aorta Remodeling in Acute Aortic Dissection: CT Scan Follow-Up.

OBJECTIVES: The aim was to evaluate the impact of a modified frozen elephant trunk procedure (mFET) on remodeling of the downstream aorta following acute aortic dissections. METHODS: Over a period of 8 years, 205 patients (mean age 62.6 ± 12.6 years) underwent a mFET (n = 69, 33.7%) or isolated ascending aorta replacement (n = 136, 66.3%) (iAoA). Aortic diameter was assessed at the aortic arch (AoA), at the mid of the thoracic aorta (mThA), at the thoracoabdominal transition (ThAbd) and at the celiac trunk level (AbdA). RESULTS: Mean follow-up was 3.3 ± 2.6 years. In-hospital mortality was 14% (n = 28), 7% in mFET and 17% in the iAoA group (p = 0.08). At the end of the follow-up, overall survival was 84% (95% CI 70-92%) and 75% (65-82%) and freedom from aorta-related reoperation was 100% and 95% (88-98%) for mFET and iAoA, respectively. At iAoA, the average difference in diameter change per year between mFET and iAoA was for total lumen 0 mm (- 0.95 to 0.94 mm, p = 0.99), and for true lumen, it was 1.23 mm (- 0.09 to 2.55 mm) per year, p = 0.067. False lumen demonstrated a decrease in diameter in mFET as compared to iAoA by - 1.43 mm (- 2.75 to - 0.11 mm), p = 0.034. In mFET, at the aortic arch level the total lumen diameter decreased from 30.7 ± 4.8 mm to 30.1 ± 2.5 mm (Δr + 2.90 ± 3.64 mm) and in iAoA it increased from 31.8 ± 4.9 to 34.6 ± 5.9 mm (Δr + 2.88 ± 4.18 mm). CONCLUSION: The mFET procedure provides satisfactory clinical outcome at short term and mid-term and has a positive impact on aorta remodeling, especially at the level of the aortic arch.

Microplegia versus Cardioplexol® in Coronary Artery Bypass Surgery with Minimal Extracorporeal Circulation: Comparison of Two Cardioplegia Concepts.

BACKGROUND: The aim of this study is to compare the combined use of the Myocardial Protection System and our microplegia (Basel Microplegia Protocol) with Cardioplexol® in coronary artery bypass grafting using the minimal extracorporeal circulation. METHODS: The analysis focused on propensity score matched pairs of patients in whom microplegia or Cardioplexol® was used. Primary efficacy endpoints were high-sensitivity cardiac troponin-T on postoperative day 1 and peak values during hospitalization. Furthermore, we assessed creatine kinase and creatinine kinase-myocardial type, as well as safety endpoints. RESULTS: A total of 56 patients who received microplegia and 155 patients who received Cardioplexol® were included. The use of the microplegia was associated with significantly lower geometric mean (confidence interval) peak values of high-sensitivity cardiac troponin-T (233 ng/L [194-280 ng/L] vs. 362 ng/L [315-416 ng/L]; p = 0.001), creatinine kinase (539 U/L [458-633 U/L] vs. 719 U/L [645-801 U/L]; p = 0.011), and creatinine kinase-myocardial type (13.8 µg/L [9.6-19.9 µg/L] vs. 21.6 µg/L [18.9-24.6 µg/L]; p = 0.026), and a shorter length of stay on the intensive care unit (1.5 days [1.2-1.8 days] vs. 1.9 days [1.7-2.1 days]; p = 0.011). Major adverse cardiac and cerebrovascular events occurred with roughly equal frequency (1.8 vs. 5.2%; p = 0.331). CONCLUSIONS: The use of the Basel Microplegia Protocol was associated with lower peak values of high-sensitivity cardiac troponin-T, creatinine kinase, and creatinine kinase-myocardial type and with a shorter length of stay on the intensive care unit, as compared with the use of Cardioplexol® in isolated coronary artery bypass surgery using minimal extracorporeal circulation.

Analysis of Myocardial Ischemia Parameters after Coronary Artery Bypass Grafting with Minimal Extracorporeal Circulation and a Novel Microplegia versus Off-Pump Coronary Artery Bypass Grafting.

BACKGROUND: To compare the performance of our institutionally refined microplegia protocol in conjunction with minimal extracorporeal circulation system (MiECC) with off-pump coronary artery bypass grafting (OPCAB). METHODS: We conducted a single center study including patients undergoing isolated CABG surgery performed either off-pump or on-pump using our refined microplegia protocol in conjunction with MiECC. We used propensity modelling to calculate the inverse probability of treatment weights (IPTW). Primary endpoints were peak values of high-sensitivity cardiac troponin T (hs-cTnT) during hospitalization, and respective first values on the first postoperative day. Endpoint analysis was adjusted for intraoperative variables. RESULTS: After IPTW, we could include 278 patients into our analyses, 153 of which had received OPCAB and 125 of which had received microplegia. Standardized differences indicated that treatment groups were comparable after IPTW. The multivariable quantile regression yielded a nonsignificant median increase of first hs-cTnT by 39 ng/L (95% CI -8 to 87 ng/L, p = 0.11), and of peak hs-cTnT by 35 ng/L (CI -13 to 84, p = 0.11), and of peak hs-cTnT by 35 ng/L (CI -13 to 84, p = 0.11), and of peak hs-cTnT by 35 ng/L (CI -13 to 84, p = 0.11), and of peak hs-cTnT by 35 ng/L (CI -13 to 84. CONCLUSION: The use of our institutionally refined microplegia in conjunction with MiECC was associated with similar results with regard to ischemic injury, expressed in hs-cTnT compared to OPCAB. MACCE was seen equally frequent. ICU discharge was earlier if microplegia was used.

Aortic root and ascending aorta dimensions in acute aortic dissection.

OBJECTIVES: Aim of this study was to evaluate ascending aorta and aortic root dimension at acute type A dissection (acute aortic dissection) and to identify demographics elements being allied to the acute event. METHODS: In a period between 2009 and 2017, 225 (n = 71, 32% female, mean age = 63 ± 12 years) patients eligible for analysis of ascending aorta and 223 (n = 70, 31% female, mean age = 63 ± 13 years) of aortic root were included in this study. Aortic diameter was assessed in preoperative computed tomography scan. The predissection diameters were modeled from the diameters obtained at diagnosis, assuming 30% augmentation of the diameter at acute event. RESULTS: The mean diameter of the ascending aorta at dissection was 46 ± 8 mm and the modeled diameter was 32.3 ± 5.7 mm. The diameter of the aortic root at dissection was 42 ± 8 mm and modeled diameter was 29.5 ± 5.6 mm. In multivariate analysis, female gender (p = 0.026) and history of cerebrovascular event (p = 0.001) were associated with acute aortic dissection in small aortic root. Patient age (p < 0.001) and history of inguinal hernia (p = 0.001) in ascending aorta <55 mm correlated with acute aortic dissection. CONCLUSION: Modeling indicates that more than 90% of patients had aortic root and ascending aorta diameter <45 mm. It seems that the aortic diameter expansion over the 55 mm in development of acute aortic dissection is overestimated. Parameters other than aortic size were identified, which may be considered when patients at high risk for dissection were identified.

Clinical implementation of a novel myocardial protection pathway in coronary artery bypass surgery with minimal extracorporeal circulation.

INTRODUCTION: The aim of this study was to report the clinical implementation of the joint use of the Myocardial Protection System (MPS®) and the minimal extracorporeal circulation system (MiECC), in conjunction with an institutionally refined dose/volume-dependent microplegia in coronary artery bypass grafting (CABG). METHODS: Patients with isolated CABG surgery were included. The final protocol to achieve cardioplegic arrest consisted of warm blood cardioplegia with 20 mmol potassium (K), 1.6 g magnesium (Mg) and 40 mg lidocaine per liter (L) blood. We prospectively collected intra- and postoperative data to monitor and validate this novel approach. RESULTS: Eighty patients were operated accordingly. Mean (SD) aortic clamping time and extracorporeal perfusion time were 67.5 (22.6) and 101.1 (31.9) minutes, respectively. Failure to induce cardiac arrest was seen in six patients at the early stage of refinement of the formula. Median (IQR) high -sensitivity cardiac troponin T (hs-cTnT) on the first postoperative day (POD) and peak hs-cTnT were 262.5 ng/L (194.3-405.8) and 265.5 ng/L (194.3-405.8), respectively. Median (IQR) creatine kinase-myocardial type (CK-MB) on POD 1 and peak CK-MB were 14.2 µg/L (10.5-22.7) and 14.2 µg/L (10.7-23.2), respectively. Median (IQR) creatine kinase (CK) on POD 1 and peak CK were 517.5 U/L (389.3-849.8) and 597.5 U/L (455.0-943.0), respectively. No patient died during hospitalization. CONCLUSIONS: The combination of this cardioplegic formula with MPS® and MiECC in CABG was safe and feasible. With the final chemical makeup, cardiac arrest was reliably achieved. Remarkably low postoperative cardiac markers indicate shielded cardiac protection during surgery.

Impact of aortic root annuloplasty on 3D aortic root geometry.

BACKGROUND: The aim was to evaluate the impact of aortic root (AoR) annuloplasty on 3D AoR deformation. METHODS: In experimental setup, Yacoub procedure and Yacoub with annuloplasty were performed. Results were compared to native AoR. In each AoR modality, six microsonometric (2 mm, 200 Hz) crystals were implanted at the sinotubular junction (STJ) and at the AoR base (AoB). 3D deformation of the AoR was determined by AoR tilt (α) and rotation (ß) angle changes. RESULTS: Tilt angle in Yacoub AoR with annuloplasty and in Yacoub AoR was maximal at ejection, 26.71 ± 0.18° and 24.91 ± 0.13°, respectively, and minimal at diastole, 25.34 ± 0.15° and 21.90 ± 0.15°, respectively. Rotation angle in Yacoub AoR with and without annuloplasty was maximal at ejection, 27.04 ± 0.25° and 23.53 ± 0.54°, respectively, and minimal at diastole, 24.84 ± 0.14° and 21.62 ± 0.16°, respectively. In native AoR, tilt angle and rotation were minimal at ejection, 14.34 ± 0.81° and 18.1 ± 3.20°, respectively, and maximal at diastole, 18.78 ± 0.84° and 21.23 ± 021°, respectively. AoB and STJ had maximal expansion at ejection; 2.59 ± 2.40% and 6.05 ± 0.66 for Yacoub and 3.75 ± 0.66% and 3.08 ± 0.24% for Yacoub with annuloplasty. In native AoR, the expansion at ejection for AoB was 7.13 ± 2.68% and for STJ was 16.42 ± 0.63%. CONCLUSIONS: AoB annuloplasty reduces AoB deformation and has an impact on STJ dynamics. In both the Yacoub AoR modalities, during ejection, the AoR takes on more of a cone-like geometry, whereas in native AoR, it is of a cylinder-like shape.

New, optimized, dual-lumen cannula for veno-venous ECMO.

OBJECTIVE: The present study was designed to assess in vivo a new, optimized, virtually wall-less, dual-lumen, bi-caval cannula for veno-venous ECMO in comparison to a commercially available cannula. METHODS: Veno-venous extracorporeal membrane oxygenation (ECMO) was carried out in a bovine study (n=5, bodyweight 75±5kg). Following systemic heparinization, ECMO was established in a trans-jugular fashion through a calibrated 23F orifice, using a new, optimized, virtually wall-less, dual-lumen, bi-caval 24F cannula (Smartcanula LLC, Lausanne, Switzerland) versus a commercially available 23F bi-caval, dual-lumen control cannula (Avalon Elite®, Maquet, Rastatt, Germany) in a veno-venous ECMO setup. Veno-venous ECMO was initiated at 500 revolutions per minute (RPM) and increased by incremental steps of 500 RPM up to 2500 RPM. Catheter outlet pressure, catheter inlet pressure, oxygen saturation and pump flow were recorded at each stage. RESULTS: Mean flow accounted for 0.37±0.04 L/min for wall-less versus 0.29± 0.07 L/min for control at 500 RPM, 0.97±0.12 versus 0.67±0.06 at 1000 RPM, 1.60±0.14 versus 1.16±0.08 at 1500 RPM, 2.31±0.13 versus 1.52±0.13 for 2000 RPM and 3.02±0.5 versus 2.11±0.18 (p<0.004). The mean venous suction required was 19±8 mmHg for wall-less versus 20±3 mmHg for control at 500 RPM, 7±3 versus 9±4 for 1000 RPM, -11±10 versus -12±8 at 1500 RPM, -39±15 versus -49±10 for 2000 RPM and -60±28 versus -94±7 for 2500 RPM. The mean venous injection pressure accounted for 29±7 mmHg for wall-less versus 27±5 mmHg for control at 500 RPM, 50±6 versus 61±7 at 1000 RPM, 89±10 versus 99±17 for 1500 RPM, 142±14 versus 161±9 at 2000 RPM and 211±41 versus 252 ±3 for 2500 RPM. CONCLUSION: Compared to the commercially available control cannula, the new, optimized, virtually wall-less, dual-lumen, bi-caval 24F cannula allows for significantly higher blood flows, requires less suction and results in lower injection pressures in vivo.

Rapid-deployment aortic valve replacement versus standard bioprosthesis implantation.

OBJECTIVE: To compare the outcome and the 1-year hemodynamic results of the rapid-deployment Intuity valve versus the Perimount Magna bioprosthesis in matched populations. METHODS: Between March 2014 and May 2015, 32 patients underwent aortic valve replacement with the Intuity valve (Intuity-group). These patients were compared to a matched population of Perimount valves implanted during the same period of time (Perimount-group). Clinical data were compared and echocardiographic 1-year follow-up was performed. RESULTS: There were more female patients in the Intuity-group (47% vs 22%, p = 0.035); mean age was 78 ± 5.6 and 72.5 ± 6 years in the Intuity-group and Perimount-group (p < 0.001); coronary disease was more common in the Intuity-group (65% vs 25%, p = 0.005). Other characteristics were similar. Implants were 100% successful. Mean cross-clamp (50.3 ± 25 vs 53 ± 22 min, p = 0.004), cardiopulmonary bypass (68 ± 27 vs 72 ± 31.8 min; p = 0.006), and surgical times (156.8 ± 54 vs 165 ± 40 min; p = 0.018) were shorter with the Intuity despite more concomitant procedures. Mean valve size was 23.7 mm (Intuity-group) and 24.1 mm (Perimount-group); hospital mortality was zero (Intuity-group) and 3% (Perimount-group); new pacemaker implants were 6% (Intuity) and 3% (Perimount) (p = 0.55) and hospital stay was equivalent. Mean gradients were: 9.9 ± 3.4 (Intuity) versus 12.5 ± 3.8 mmHg (Perimount) (p = 0.022) at discharge and 9 ± 4 mmHg (Intuity) versus 14 ± 4 mmHg (Perimount) (p = 0.02) at follow-up. At discharge, one Intuity valve had 3+ aortic insufficiency (AI) which was unchanged at 1 year and will require an intervention. Another patient had 1 + AI which progressed to 2+ at 1 year. There were no paravalvular leaks in the Perimount valves at discharge and follow-up. CONCLUSION: Intuity valves showed lower gradients compared to Perimount valves with the same mean size. Paravalvular leaks identified at the time of implantation in Intuity valves need to be addressed at the time of surgery.

Analysis of flow dynamics in right ventricular outflow tract.

BACKGROUND: The mechanism behind early graft failure after right ventricular outflow tract (RVOT) reconstruction is not fully understood. Our aim was to establish a three-dimensional computational fluid dynamics (CFD) model of RVOT to investigate the hemodynamic conditions that may trigger the development of intimal hyperplasia and arteriosclerosis. METHODS: Pressure, flow, and diameter at the RVOT, pulmonary artery (PA), bifurcation of the PA, and left and right PAs were measured in 10 normal pigs with a mean weight of 24.8 ± 0.78 kg. Data obtained from the experimental scenario were used for CFD simulation of pressure, flow, and shear stress profile from the RVOT to the left and right PAs. RESULTS: Using experimental data, a CFD model was obtained for 2.0 and 2.5-L/min pulsatile inflow profiles. In both velocity profiles, time and space averaged in the low-shear stress profile range from 0-6.0 Pa at the pulmonary trunk, its bifurcation, and at the openings of both PAs. These low-shear stress areas were accompanied to high-pressure regions 14.0-20.0 mm Hg (1866.2-2666 Pa). Flow analysis revealed a turbulent flow at the PA bifurcation and ostia of both PAs. CONCLUSIONS: Identified local low-shear stress, high pressure, and turbulent flow correspond to a well-defined trigger pattern for the development of intimal hyperplasia and arteriosclerosis. As such, this real-time three-dimensional CFD model may in the future serve as a tool for the planning of RVOT reconstruction, its analysis, and prediction of outcome.

The aortic root: simple as possible, but not simpler.

During the past decades, replacement of the aortic valve (AVR) was considered a straightforward treatment of aortic valve disease. The technique is simple, with a relatively low perioperative mortality and morbidity (3-5%) and, as such, does not require a detailed knowledge of aortic root anatomy. However, with the renaissance of reconstructive procedures on the aortic root, an increased use of biological aortic valve prostheses (especially of stentless devices) and, finally, the revival of the Ross procedure, a more detailed understanding of aortic root function and morphology was required in the operating room.

Aortic root rotation: morphological analysis of the aortic root with three-dimensional computed tomography.

OBJECTIVES: The aortic root (AoR) rotation and its spatial morphology at the base of the heart were postulated but not described in every detail. AoR rotation modalities may play an important role in decision-making during AoR surgery and its outcome. The aim was to provide a detailed spatial anatomy of the AoR rotation and its relation to the vital surrounding structure. METHODS: The AoR rotation and its relation to the surrounding structure were assessed in 104 patients with tricuspid aortic valve. The interatrial septum was chosen as a reference to describe AoR rotation that marked the midline of the heart base as a landmark for the AoR rotation direction. Intermediate, clockwise and counterclockwise AoR rotations were defined based on the mentioned reference structures. RESULTS: The AoR rotation was successfully assessed in 104 patients undergoing ascending aorta and or AoR intervention by multidetector row computed tomography. AoR was positioned normally in 53.8% of cases (n = 56) and rotated counterclockwise in 5.8% (n = 6) and clockwise in 40.4% (n = 42) of cases. In clockwise AoR rotation, the right coronary sinus was positioned in proximity to the right atrium and of the tricuspid valve, whereas in a counterclockwise rotation, the noncoronary sinus was placed over the tricuspid valve just over the membranous septum. CONCLUSIONS: The AoR's rotation can be diagnosed using multidetector row computed tomography. Understanding the anatomy of the aortic valve related to rotational position helps guide surgical decision-making in performing AoR reconstruction.

In-Hospital Graft Occlusion in Post-Coronary Artery Bypass Grafting Patients in the Early Postoperative Period: A Systematic Review and Meta-Analysis.

Objectives: The objectives of this paper are to evaluate the incidence of early graft occlusion during hospital stays following coronary bypass surgery (CABG) and to assess the factors influencing the odds of in-hospital early graft occlusion. Methods: Reports evaluating the early in-hospital occlusion of coronary bypass grafts were identified through PubMed, Embase, and Cochrane databases. The primary endpoint was to determine the incidence of early graft occlusion following CABG before discharge and to identify and quantify the impact of demographic, clinical, and procedural risk factors on the occurrence of early graft occlusion. The meta-analysis was conducted using a random-effects inverse-variance model with the DerSimonian-Laird estimator, assessing incidence rates, risk factors, and study heterogeneity, with statistical analysis performed using Stata. Results: A total of 22 studies with 35,798 patients were included in the analysis. The overall incidence of in-hospital early graft occlusion was 5% (95% CI: 3% to 7%). In studies using symptom-driven patency assessment, the incidence of occlusion was 2%, whereas in those employing systematic graft patency assessment, it was 6%. Only the presence of a vein graft OR 2.13 (95% CI: 1.19-3.82) was significantly associated with in-hospital graft occlusion. Conclusions: The incidence of in-hospital early graft occlusion seems substantially underestimated if imaging is restricted only to symptomatic patients. Moreover, female gender, increased PI, and the presence of a composite graft could also be potential risk factors for this complication.

Early silent coronary bypass graft occlusion following coronary bypass surgery, implication of routine coronary computed tomography angiography.

Objective: To evaluate incidence and predictors of early silent bypass occlusion following coronary bypass surgery using cardiac computed tomography angiography. Methods: A total of 439 consecutive patients with mean age of 66 ± 10 years comprising 17% (n = 75) females underwent isolated coronary bypass surgery followed by CT scan before discharge. Graft patency was evaluated in 1,319 anastomoses where 44% (n = 580) arterial and 56% (n = 739) vein graft anastomosis were performed. Cardiovascular risk factors, demographics, and intraoperative variables were analyzed. We conducted univariable and multivariable logistic regression analyses to analyze variables potentially associated with graft occlusion following CABG. Variables included gender, surgery duration, graft flow, pulsatility index, vein vs. artery graft, and recent MI. Results: Overall incidence of graft occlusion was 2.4% (31/1,319), and it was diagnosed in 6.6% (29/439) of patients. The difference in occlusion between arterial (2.1%) and vein (2.6%) grafts was not significant, p = 0.68. The duration of intervention p = 0.034, cross clamp time p = 0.024 as well the number of distal anastomosis p = 0.034 were significantly higher in occlusion group. The univariate and multivariate logistic regression indicated duration of surgery being predictive for bypass graft occlusion with OR = 1.18; 95% CI: 1.01-1.38; p = 0.035. Conclusions: Early graft occlusion was associated with surgical factors. The number of distant anastamoses, along duration of surgical intervention were, significantly influenced the risk of EGO. Prolonged procedural time reflecting complex coronary pathology and time-consuming revascularization procedure was as well associated to the elevated risk of occlusion.

Estimation of Systolic and Diastolic Left Ventricular Blood Flow From Derivatives of Transesophageal Echocardiographic 3D Volume Curves in Cardiac Surgery Patients: A Proof-of-Concept Study.

OBJECTIVES: To examine whether estimates of peak global systolic (S') and diastolic (E') left ventricular (LV) flow rates based on 3D echocardiographic volumes are feasible and match physiology. METHODS: In this retrospective feasibility study, we included patients undergoing major cardiac surgery. S' and E' were derived from 190 patients by taking the first derivative of the volume-time relationship of 3D ecg-gated transesophageal echocardiography (TEE) images. To examine the quality of images upon which the estimates of flow were based we correlated intraoperative 3D TEE and preoperative 2D transthoracic echocardiography (TTE) volumes. As a proof-of-concept, we then correlated S' flow with stroke volume and S' and E' were compared by valve pathology. RESULTS: In each of the 190 images, S' and E' were derived. There was good correlation between 1) the ejection fraction (EF) of 3D LV images obtained intraoperatively by TEE and preoperatively by TTE (Pearson's r = 0.65) and also 2) S' and stroke volume (Pearson's r = 0.73). Patients with aortic or mitral regurgitation showed higher S' than patients without valve pathologies (-315 mL/s [95% CI -388 mL/s to -264 mL/s]P = 0.001, -319 mL/s [95% CI -397 mL/s to -246 mL/s]P = 0.001 vs -242 mL/s [95% CI -300 mL/s to -196 mL/s]). These patients also showed higher E' than patients without valve pathologies (302 mL/s [95% CI 237 mL/s to 384 mL/s]P = 0.006, 341 mL/s [95%CI 227 mL/s to 442 mL/s]P = 0.001 vs 240 mL/s [95%CI 185 mL/s to 315 mL/s]). Patients with aortic stenosis showed no difference in S' or E' (-263 mL/s [95%CI -300 mL/s to -212 mL/s]P = 0.793, 255 mL/s [95%CI 188 mL/s to 344 mL/s]P = 0.400). CONCLUSIONS: Estimates of global peak systolic and diastolic LV flow based on 3D TEE are feasible, promising, and match valve pathologies.

Aortic root rupture: implications of catheter-guided aortic valve replacement.

PURPOSE OF REVIEW: The safety and efficiency of trans catheter aortic valve implantation (TAVI) has been clearly demonstrated. In high-risk patients, the number of procedures is constantly increasing and in western European countries this procedure is employed in more than 30% of isolated aortic valve replacements. The literature, however, focusing on perioperative aortic root (AoR) rupture is rather limited to just a few reports. The aim of this review is to analyze the pathophysiology of AoR rupture during TAVI, stressing the implications of the morphology of the AoR for this devastating complication. RECENT FINDINGS: Currently, perioperative AoR rupture ranges between 0.5 and 1.5% during TAVI, with almost 100% mortality. Recently, valve oversizing and balloon dilatation in a calcified and small AoR were considered as the most important predictive factors for this complication. SUMMARY: The most fragile unit of the AoR is its anchoring substrate to the ostium of the left ventricle. This membranous structure is not involved in the degenerative process leading to aortic valve stenosis. Due to the TAVI and/or balloon dilatation of the calcium stationed on the three leaflets and their attachment, a lesion may result on this structure. And, as a consequence, there is rupture of the AoR.