What future for coronary artery bypass surgery.

The future of coronary artery bypass graft can be bright if cardiac surgeons will change the paradigm followed so far and will return in history, abandoning the current comfortable life and accepting the burden represented by the cost of innovation, which has a path already mapped out but not sufficiently trodden for guilty lack of commitment.

How to recycle a misused left internal thoracic artery: Tips and tricks.

In this case report, we describe how to recycle the left internal thoracic artery (LITA) when misused but not damaged. Eight years after a left anterior small thoracotomy followed by left anterior descending (LAD) stenting for STEMI in first postoperative day, a 67-years-old woman had an NSTEMI with angiographic evidence of intrastent re-stenosis with a perfectly patent LITA, harvested only from the fourth to the sixth intercostal space. During redo surgery, LITA was harvested as a pedicle from the anastomosis to the fourth intercostal space and primarily from the first to the fourth intercostal space. Special attention was paid at the level of the fourth intercostal space where the vessel was stuck to the sternum: a 15-blade was used being scissors or cautery too dangerous. At the end of harvesting, the LITA was full-length available for a new coronary anastomosis on LAD, distal to the previous one.

Features of degenerative mitral valve prolapse in the North East of China: repair characteristics, and short-term follow-up results.

BACKGROUND: We aimed to assess the clinical and echocardiographic characteristics of patients who underwent surgery for degenerative mitral valve prolapse (MVP) in our center, and its relation to outcomes. METHODS: We enrolled 117 consecutive patients from North-East China with an echocardiographic diagnosis of MVP related mitral regurgitation (MR) between April 2018 and November 2019. A complexity scoring system was used for valve anatomy, and patients were re-evaluated at 3-6 months after surgery. RESULTS: Most patients (57.3%) were 40-59 years old. Ejection fraction was <60% in one third, and pulmonary hypertension was present in 64.3% of operated patients. Etiology was myxomatous in 58.9%, with flail as main lesion. Leaflet involvement was posterior in 59.8% patients, anterior in 32.5%, bileaflet in 6%, and commissural in 25.6%. Lesion score was intermediate in >50% of patients, and myxomatous lesions scored higher compared to fibroelastic deficiency (FED). Degree of MR left atrial volume and estimated wedge pressure were significantly higher in intermediate and complex lesions. Repair was performed in 93/101 patients (95.8% success rate). No in-hospital major adverse events, nor deaths at follow-up were reported. Residual MR was ≤ mild in 86.7% of patients at follow-up and was associated with FED etiology and complex lesions. CONCLUSIONS: Compared to Western countries, in our sample of Chinese population degenerative severe MR occurred in younger patients. The MVP lesion characteristics are similar, can be accurately detected by non-invasive preoperative evaluation, allowing predictable results. Advanced tailored repair techniques allow excellent immediate and short-term results regardless of the underlying complexity.

Committee Recommendations for Resuming Cardiac Surgery Activity in the SARS-CoV-2 Era: Guidance From an International Cardiac Surgery Consortium.

Recommendations for the safe and optimized resumption of cardiac surgery care, research, and education during the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) era were developed by a cardiovascular research consortium, based in 19 countries and representing a wide spectrum of experience with COVID-19. This guidance document provides a framework for restarting cardiac surgery in the outpatient and inpatient settings, in accordance with the current understanding of SARS-CoV-2, the risks posed by interrupted cardiovascular care, and the available recommendations from major societies.

Minimally Invasive coronary surgery compared to STernotomy coronary artery bypass grafting: The MIST trial.

RATIONALE: Minimally invasive cardiac surgery has emerged as a safe alternative to standard cardiac surgery. Minimally invasive coronary surgery (MICS CABG) was developed to allow adequate exposure and complete revascularization in CABG from a small thoracotomy incision without cardiopulmonary bypass. Multiple studies have reported significant shorter length of hospital stay and earlier postoperative physical recovery for MICS CABG patients when compared to sternotomy CABG patients. However, there have been no convincing clinical trials that demonstrate improvement in post-operative quality of life for patients who undergo MICS CABG. STUDY DESIGN: The Minimally Invasive Coronary Surgery compared to Sternotomy Coronary Artery Bypass Grafting (MIST) trial is a multi-centered, prospective randomized controlled trial that compares the quality of life and recovery in the early post-operative period between patients undergoing MICS CABG versus patients undergoing sternotomy CABG. Patients will be randomized either to the MICS CABG group or the sternotomy CABG group, and the target enrollment is 88 patients per group. The primary outcome is quality of life assessment performed by SF-36 questionnaire at 1 month. CONCLUSION: The MIST trial is the first prospective study that compares the quality of life between MICS CABG and sternotomy CABG patients. The results of this trial may enhance the procedural desirability of MICS CABG by patients and provide an incentive for surgeons and institutions to increase the availability of MICS CABG in suitable patients.

In vitro assessment of mitral valve function in cyclically pressurized porcine hearts.

Recent approaches to the in vitro experimental study of cardiac fluid mechanics involve the use of whole biological structures to investigate in the lab novel therapeutic approaches for the treatment of heart pathologies. To enhance reliability and repeatability, the influence of the actuation strategy of the experimental apparatuses on the biomechanics of biological structures needs to be assessed. Using echography and intracardiac high-speed imaging, we compared the mitral valve (MV) anatomo-functional features (coaptation areas/lengths, papillary muscles-valvular plane distances) in two passive-beating-heart mock loops with internal (IPML) or external (EPML) pressurization of the ventricular chamber. Both apparatuses showed fluid dynamic conditions that closely resembled the physiology. The MVs analyzed in the EPML presented coaptation areas and lengths that were systematically higher, and exhibited greater variability from early-to peak-systole, as compared to those in the IPML. Moreover, in the EPML, the MV leaflets exhibited a convexity with high curvature toward the atrium. With the IPML, MV coaptation lengths ranged similar to available clinical data and the papillary muscles-valve plane distances were more stable throughout systole. In conclusion, both the apparatuses allow for reproducing in vitro the left heart hemodynamics, in terms of flow rates and pressures, with proper mitral valve continence. Results suggest that the IPML is more suitable for replicating the physiological MV functioning, while the EPML may have more potential as a model for the study of MV pathologies.

A geometric approach to aortic root surgical anatomy.

OBJECTIVES: The aim of this study was the analysis of the geometrical relationships between the different structures constituting the aortic root, with particular attention to interleaflet triangles, haemodynamic ventriculo-arterial junction and functional aortic annulus in normal subjects. METHODS: Sixteen formol-fixed human hearts with normal aortic roots were studied. The aortic root was isolated, sectioned at the midpoint of the non-coronary sinus, spread apart and photographed by a high-resolution digital camera. After calibration and picture resizing, the software AutoCAD 2004 was used to identify and measure all the elements of the interleaflets triangles and of the aortic root that were objects of our analysis. Multiple comparisons were performed with one-way analysis of variance for continuous data and with Kruskal-Wallis analysis for non-continuous data. Linear regression and Pearson's product correlation were used to correlate root element dimensions when appropriate. Student's t-test was used to compare means for unpaired data. Heron's formula was applied to estimate the functional aortic annular diameters. RESULTS: The non coronary-left coronary interleaflets triangles were larger, followed by inter-coronary and right-non-coronary ones. The apical angle is <60° and its standard deviation can be considered an asymmetry index. The sinu-tubular junction was shown to be 10% larger than the virtual basal ring (VBR). The mathematical relationship between the haemodynamic ventriculo-arterial junction and the VBR calculated by linear regression and expressed in terms of the diameter was: haemodynamic ventriculo-arterial junction = 2.29 VBR (diameter) + 47. DISCUSSION: Conservative aortic surgery is based on a better understanding of aortic root anatomy and physiology. The relationships among its elements are of paramount importance during aortic valve repair/sparing procedures and they can be useful also in echocardiographic analysis and in computed tomography reconstruction.

Aortic valve repair: a ten-year single-centre experience†.

OBJECTIVES: Aortic valvuloplasty could represent an alternative to valve replacement resulting in optimal haemodynamic conditions, avoiding anticoagulation and allowing, in young people, normal aortic annulus growth. We analysed our results of aortic valve repair for incompetence due to leaflets and root pathology. METHODS: From January 2003 to January 2013, 235 patients affected by aortic valve regurgitation, pure or associated with aortic dilatation, were treated with a combination of the principal leaflet repair techniques and, when necessary, sparing procedures. Of these patients, 218 were considered eligible in this study. All of them were submitted to pre- and postoperative transthoracic echocardiography and pre- and post-repair transoesophageal echocardiography. Follow-up was achieved with periodic echocardiograms and clinical evaluations. RESULTS: Eight patients (3.40%) died before discharge. Median clinical and echocardiographic follow-up for all patients was 2.94 (1.41-5.41) years. Mean cross-clamping time was 101.94 ± 40.22 min and mean hospital stay was 10 ± 6.69 days. Kaplan-Meier freedom from aortic regurgitation >2 and freedom from aortic valve replacement were, respectively, 92.9 ± 2.8 and 94.5 ± 2.5% at 9.24 years: 6 patients (2.75%) were reoperated on with aortic valve replacement for severe aortic regurgitation. We also observed a good effect of aortic surgery on the left ventricle: the end-diastolic volume decreased from 137.89 ± 50.23 ml in the preop to 105.17 ± 31.19 ml at follow-up. CONCLUSIONS: Aortic valve leaflet repair seems to be a good and feasible option for selected patients, both alone or associated with an aortic sparing technique concerning long-term results.

Aortic interleaflet triangles reshaping: hydrodynamic, kinematic and morphological effects in in-vitro analysis.

BACKGROUND AND AIM OF THE STUDY: Subcommissural triangles reshaping is a reparative technique used to remodel the ventriculo-aortic junction. The study aim was to evaluate, by means of in-vitro testing, the effects of this technique on hemodynamics, leaflet kinematics and aortic root functional unit morphology. METHODS: Twenty-one porcine aortic roots were tested in a pulsatile mock loop under basal conditions and after subcommissural triangles reshaping performed at 50% of the interleaflet triangles height. During each test, hydrodynamic quantities, high-speed digital videos and echocardiographic images were recorded. RESULTS: The comparison between pre- and post-surgery data showed a statistically significant increase in coaptation height (p < 0.01) and length (p < 0.01). Significant reductions were found in the virtual basal ring diameter (p < 0.01), sinus of Valsalva diameters (p < 0.01), maximum leaflet opening (p < 0.01), leaflet opening before rapid valve closing time (p < 0.01) and maximum opening area (p < 0.01). An opened valve time reduction (p <0.01) was observed due to an opening time reduction (p < 0.01), offset by a closed valve time increase (p < 0.01). A slow closing period increase (p < 0.07) and a rapid closing phase reduction (p < 0.01), were also highlighted without influence on the total closing time. A statistical, but not clinically significant, increase in pressure drop across the valve (p < 0.01) and an effective orifice area reduction (p < 0.01) were observed. CONCLUSION: Subcommissural triangles reshaping performed at 50% of the interleaflet triangles' height determines an increase in leaflet coaptation by remodeling the ventriculo-aortic junction. Some hydrodynamic and kinematic changes also occur, without any acute clinically threatening alterations.

Minimally invasive cardiac surgery-coronary artery bypass graft.

Coronary artery bypass graft (CABG) is among the most common operations performed in the world. Different surgical strategies can be used with different invasiveness. This paper describes a recent development of the technique that merges the advantages resulting from both the adoption of an 'off-pump no-touch aorta operation' and a 'complete arterial revascularization through a left minithoracotomy' in a single procedure. This operation is currently known with the acronym MICS (minimally invasive cardiac surgery)-CABG (minimally invasive cardiac surgery). It is an off-pump operation performed through a minithoracotomy in the fourth or fifth left intercostal space across the midclavicular line. The left internal thoracic artery (LITA) is harvested under direct vision using a special rib-retractor with multiple interchangeable thoracotomy blades, including blades to use with lift systems for proximal artery harvesting, while the right radial artery (RA) is harvested endoscopically. A Y-connection is made between the two arteries. The LITA is used to bypass the left anterior descending coronary artery, while the right RA is used on the obtuse marginal branches and/or the posterior descending coronary artery. A special coronary stabilizer and a heart positioner with a shaft for remote thoracic insertion are needed.

On-pump versus off-pump coronary artery bypass surgery in high-risk patients: operative results of a prospective randomized trial (on-off study).

OBJECTIVE: To analyze the risk reduction of cardiopulmonary bypass complications between on-pump and off-pump coronary artery bypass grafting in high-risk patients. METHODS: This multicenter, prospective, randomized, parallel trial enrolled patients for elective or urgent isolated coronary artery bypass grafting with an additive European System for Cardiac Operative Risk Evaluation of 6 or more. The patients in cardiogenic shock were excluded. The composite primary end point included operative mortality, myocardial infarction, stroke, renal failure, reoperation for bleeding and adult respiratory distress syndrome within 30 days after surgery. The total sample size was 693 patients, according to a scheduled interim analysis at 400 patients enrolled (α-spending = 0.029, Pocock method). RESULTS: A total of 411 patients were included in the interim analysis. Randomization assigned 203 patients to on-pump and 208 patients to off-pump treatment. Of the 411 patients, 24 crossed over; thus, 195 patients were actually treated on-pump and 216 off-pump. According to the intention to treat analysis, the rate of the composite primary end point was significantly lower (unadjusted P = .009, adjusted P = .010) in the off-pump group (5.8% vs 13.3%). The risk of experiencing the primary end point was significantly greater for the on-pump group (unadjusted odds ratio, 2.51; 95% confidence interval, 1.23-5.10; P = .011; adjusted odds ratio, 3.07; 95% confidence interval, 1.32-7.14; P = .009). CONCLUSIONS: Off-pump coronary artery bypass grafting reduces early mortality and morbidity in high-risk patients.

The aortic interleaflet triangles annuloplasty: a multidisciplinary appraisal.

OBJECTIVE: Aortic interleaflets triangles annuloplasty (AITA) reduces interleaflet triangles' circumferential extent through properly placed sutures. To achieve aortic root functional unit (ARFU) stabilization, we aimed at quantifying the effect of suture extent (SE) on aortic valve function and at finding general optimization criteria. METHODS: A previously published ARFU finite element model was modified to simulate ARFU dilation and AITA, systematically varying the SE and quantifying the corresponding regurgitant orifice (RO), leaflets co-aptation area (CA) and annular diameter (D(a)). Computational outcomes were tested by comparison with postoperative virtual basal ring echo data of 105 successfully corrected ARFUs. RESULTS: According to our finite element simulations of AITA, RA and CA depended linearly on SE, through a relationship that predicted optimal surgical results when SE was equal to 48% of the interleaflet triangle height (ITH). Follow-up data showed that, after AITA, ARFU diameter decreased from 23.4 ± 3.93 to 20.1 ± 1.8mm, (p<0.05) at the annulus, from 41.53 ± 6.347 to 38.2 ± 4.0 mm, (p<0.01) at the sinuses, and from 41.3 ± 6.47 to 35.25 ± 5.95 mm (p=ns) at the sinotubular junction (STJ). The mean ITH was 11.18 ± 1.74 mm and the mean SE predicted by our model was 5.34 ± 0.6mm, that is, 47.76% of the ITH, comparable to 48% of the computational model. Leaflet co-aptation length (CL) increased from 2.73 ± 1.25 to 7.56 ± 2.36 mm (p<0.001), while the CA evaluated via finite element modeling changed from 8% to 48%. CONCLUSIONS: So far, the AITA seems to be a valuable technique to increase leaflet CL in aortic valve repair and in silico models seem to be able to predict the principles of the phenomena but not the individual complexity.

Radial artery versus saphenous vein conduits for coronary artery bypass surgery: forty years of competition--which conduit offers better patency? A systematic review and meta-analysis.

The internal thoracic artery is the most effective conduit for coronary artery bypass surgery; however, most patients have multivessel disease and require additional saphenous vein or radial artery grafts. In this systematic review of the literature and meta-analysis, we aim to compare reported patency rates for these conduits and explore if differences are homogeneous across follow-up intervals. A literature search was performed using Embase, Medline, Cochrane Library, Google Scholar and randomised controlled trial databases to identify studies published between 1965 and October 2009. All studies reporting angiographic comparison of saphenous vein and radial artery conduit patency were included, irrespective of language. The end point was angiographic graft patency stratified over different follow-up intervals. Meta-analysis was performed according to recommendations from the Cochrane Collaboration and Meta-analysis Of Observational Studies in Epidemiology guidelines. We used a random-effect model and the odds ratio as the summary statistic. A total of 35 studies were identified. They reported early patency (≤ 1 year, 6795 grafts), medium-term patency (1-5 years, 3232 grafts) and long-term patency (>5 years, 1157 grafts). Significant variation of comparative patency existed across different follow-up intervals. Early saphenous vein patency was similar to radial artery patency with odds ratio of 1.04 (95% confidence interval 0.68-1.61). Medium-term saphenous vein patency, however, deteriorated significantly (odds ratio 2.06, 95% confidence interval 1.29-3.29). Similarly, long-term patency was better for radial artery conduits (odds ratio 2.28, 95% confidence interval 1.32-3.94). Heterogeneity was due to angiographic patency characteristics and related to risk of bias. In conclusion, the findings of this systematic review of the published literature and meta-analysis support the use of radial artery in preference to saphenous vein conduits for coronary artery bypass surgery.

Finite element modelling of the tricuspid valve: A preliminary study.

The incomplete efficacy of current surgical repair procedures of the tricuspid valve (TV) demands a deeper comprehension of the physiological TV biomechanics. To this purpose, computational models can provide quantitative insight into TV biomechanical response and allow analysing the role of each TV substructure. We present here a three-dimensional finite element model of the tricuspid valve that takes into account most of its peculiar features. Experimental measurements were performed on human and porcine valves to obtain a more detailed TV anatomical framework. To overcome the complete lack of information on leaflets mechanical properties, we performed a sensitivity analysis on the parameters of the adopted non-linear hyperelastic constitutive model, hypothesizing three different parameter sets for three significant collagen fibre distributions. Results showed that leaflets' motion and maximum principal stress distribution were almost insensitive to the different material parameters considered. Highest stresses (about 100kPa) were located near the annulus of the anterior and septal leaflets, while the posterior leaflet experienced lower stresses (about 55kPa); stresses at the commissures were nearly zero. Conversely, changes in constitutive parameters deeply affected leaflets' strains magnitude, but not their overall pattern. Strains computed assuming that TV leaflets tissue are reinforced by a sparse and loosely arranged network of collagen fibres fitted best experimental data, thus suggesting that this may be the actual microstructure of TV leaflets. In a long-term perspective, this preliminary study aims at providing a starting point for the development of a predictive tool to quantitatively evaluate TV diseases and surgical repair procedures.

A novel approach to the in vitro hydrodynamic study of the aortic valve: mock loop development and test.

The aortic root functional unit (ARFU) is a complex structure whose functions are strictly dependent on the biomechanical interaction among each of its anatomically defined elements. The classical approach to the in vitro study of aortic hydrodynamics does not take this complexity into account. We propose a novel methodology based on the possibility to house whole natural ARFU samples in a purposely designed pulsatile mock loop, allowing for aortic surgery simulation. To point out the usability and potentialities of the device, the mock loop was tested with untreated porcine ARFU samples and with one ARFU prosthesized with a state-of-the-art bioprosthesis. The sample holder design was proved to allow the clinician to house and treat the ARFU sample in the mock loop with easiness and repeatability. The valve leakage with the prosthesized ARFU was comparable with literature data, and Effective orifice areas were consistent with the constructor's data. In contrast, the recorded pressure drops exceeded the data from the manufacturer and were quite aligned with in vivo postop echo-Doppler data acquired in implant recipients. This result suggests that our apparatus and methodology provide a way to investigate aortic hydrodynamic phenomena that resemble in a close way to those taking place in the final recipients' circulation.

Right mini-thoracotomy for left maze with transesophageal echo guidance.

Minimally invasive surgery (MIS) is widening with the development of new specialized instrumentation, allied with improved surgical experience and techniques, some of which have shown to be effective for the ablation of atrial fibrillation (AF). These developments enable us to achieve a so-called 'ideal procedure', epicardially on beating hearts, with less operative risk, high cure rates and rapid patient recovery. Epicor (St Jude Medical, Sunnyvale, CA, USA) low profile (LP) system is a device using high intensity focused ultrasound (HIFU). We describe the use of this technology for ablation of AF through MIS approach using transesophageal echocardiography (TEE) to pilot the ablation on mitral isthmus. Ten patients underwent monolateral small thoracotomy, through the 4th intercostal space. HIFU was carried out in all cases to create an epicardial box lesion of the pulmonary veins (PVs) and mitral isthmus. TEE was employed to guide the positioning of the ablation device on mitral isthmus, in all patients. There were no mortalities or major complications, including pacemaker implantation. One patient had postoperative atrial tachycardia and was cardioverted before hospital discharge. Three patients had a postoperative AF and were scheduled for cardioversion after three months, and one patient spontaneously revealed a normal sinus rhythm (SR). During the follow-up period, all patients recorded a normal SR. We consider Epicor LP system safe and effective for AF ablation through a single right minimal invasive approach.