Impact of early versus class I-triggered surgery on postoperative survival in severe aortic regurgitation: An observational study from the Aortic Valve Insufficiency and Ascending Aorta Aneurysm International Registry.

OBJECTIVES: Class I triggers for severe and chronic aortic regurgitation surgery mainly rely on symptoms or systolic dysfunction, resulting in a negative outcome despite surgical correction. Therefore, US and European guidelines now advocate for earlier surgery. We sought to determine whether earlier surgery leads to improved postoperative survival. METHODS: We evaluated the postoperative survival of patients who underwent surgery for severe aortic regurgitation in the international multicenter registry for aortic valve surgery, Aortic Valve Insufficiency and Ascending Aorta Aneurysm International Registry, over a median follow-up of 37 months. RESULTS: Among 1899 patients (aged 49 ± 15 years, 85% were male), 83% and 84% had class I indication according to the American Heart Association and European Society of Cardiology, respectively, and most were offered repair surgery (92%). Twelve patients (0.6%) died after surgery, and 68 patients died within 10 years after the procedure. Heart failure symptoms (hazard ratio, 2.60 [1.20-5.66], P = .016) and either left ventricular end-systolic diameter greater than 50 mm or left ventricular end-systolic diameter index greater than 25 mm/m2 (hazard ratio, 1.64 [1.05-2.55], P = .030) predicted survival independently over and above age, gender, and bicuspid phenotype. Therefore, patients who underwent surgery based on any class I trigger had worse adjusted survival. However, patients who underwent surgery while meeting early imaging triggers (left ventricular end-systolic diameter index 20-25 mm/m2 or left ventricular ejection fraction 50% to 55%) had no significant outcome penalty. CONCLUSIONS: In this international registry of severe aortic regurgitation, surgery when meeting class I triggers led to postoperative outcome penalty compared with earlier triggers (left ventricular end-systolic diameter index 20-25 mm/m2 or ventricular ejection fraction 50%-55%). This observation, which applies to expert centers where aortic valve repair is feasible, should encourage the global use of repair techniques and the conduction of randomized trials.

Coronary Perfusion After Valve-in-Valve Transcatheter Aortic Valve Implantation in Small Aortic Root: In Vitro Experimental Assessment.

Coronary flow obstruction following transcatheter aortic valve-in-valve implantation (VIV-TAVI) is associated with a high mortality risk. The aim of this work was to quantify the coronary perfusion after VIV-TAVI in a high-risk aortic root anatomy. 3D printed models of small aortic root were used to simulate the implantation of a TAVI prosthesis (Portico 23) into surgical prostheses (Trifecta 19 and 21). The aortic root models were tested in a pulsatile in vitro bench setup with a coronary perfusion simulator. The tests were performed at baseline and post-VIV-TAVI procedure in aligned and misaligned commissural configurations under simulated hemodynamic rest and exercise conditions. The experimental design provided highly controllable and repeatable flow and pressure conditions. The left and right coronary mean flow did not differ significantly at pre- and post-VIV-TAVI procedure in any tested configurations. The commissural misalignment did not induce any significant alterations to the coronary flow. High-risk aortic root anatomy did not trigger coronary ostia obstruction or coronary flow alteration after transcatheter aortic valve implantation in a surgical bioprosthesis as shown from in-vitro flow loop tests.

Morphometric Characterization of an Ex Vivo Porcine Model of Functional Tricuspid Regurgitation.

Emerging treatments for tricuspid valve (TV) regurgitation require realistic TV pathological models for preclinical testing. The aim of this work was to investigate structural features of fresh and defrosted porcine right-heart samples as models of mild and severe functional tricuspid regurgitation (FTR) condition in ex-vivo pulsatile flow platform. Ten fresh hearts were tested ex-vivo under steady and pulsatile flow in typical right-heart loading conditions. Hemodynamics and 3D echocardiographic imaging of TV and right ventricle (RV) were acquired. Hearts were then kept frozen for 14 days, defrosted, and tested again with the same protocol. Morphometric parameters of TV and RV were derived from 3D reconstructions based on echo data. Fresh samples showed a slightly dilated TV morphology, with coaptation gaps among the leaflets. Sample freezing induced worsening of TV insufficiency, with significant (p < 0.05) increases in annulus size (annulus area and perimeter 7.7-3.1% respectively) and dilation of RV (9.5%), which led to an increase in tenting volume (123.7%). These morphologic alterations reflected into a significant increment of regurgitation fraction (27%). Together, such results suggest that fresh porcine heart samples may be a reliable ex-vivo model of mild FTR condition, which can be enhanced through freezing/thawing treatment to model a severe pathological condition.

Commissural repositioning in bicuspid aortic valve repair: an in vitro acute model to explore and explain different results.

OBJECTIVES: Commissural orientation <160° is a recognized risk factor for bicuspid aortic valve repair failure. Based on this observation, repairing this subtype of aortic valve by reorienting the 2 commissures at 180° has recently been proposed. METHODS: Nine porcine hearts with aortic annulus diameters of 25 mm were selected. A pathological model of a Sievers 1 bicuspid aortic valve was obtained by suturing the coaptation line between the left and right leaflets. Each heart underwent reimplantation procedures both in the native (120°) and the reoriented (180°) configuration. After the operation, each sample was tested on a pulse duplicator at rest (heart rate 60 beats per min) and with mild exercise (heart rate 90 beats per min) conditions. RESULTS: No statistically significant difference was noted in mean and peak transvalvular aortic gradients between the 2 configurations at rest (18.6 ± 5 vs 17.5 ± 4 for the mean aortic gradient; 42.8 ± 12.7 vs 36.3 ± 5.8 for the peak aortic gradient) but the group with the 120°-oriented commissures had significantly higher mean transaortic gradients compared to the group with the 180°-oriented commissures at initial exercise stress conditions (30.1 ± 9.1 vs 24.9 ± 3.8; p value 0.002). CONCLUSIONS: The 180° commissural reorientation of the asymmetrical bicuspid aortic valve does not improve the transvalvular aortic gradient in an acute model at rest conditions, but it could do so under stress situations. Even if it is surgically more complex and time-consuming, this approach could be a good strategy to improve long-term results, particularly in young patients.

Hybrid Surgery to Manage Aortic Arch Pathology.

Background and Objectives: Aortic arch disease is still a high-risk surgical challenge despite major advances both in surgical and anesthesiological management. A combined surgical and endovascular approach has been proposed for aortic arch disease treatment to avoid hypothermia and circulatory arrest in high-risk patients. Materials and Methods: Between June 2004 and June 2021, 112 patients were referred to our department for aortic arch surgery; 38 (33.9%) patients underwent supra-aortic debranching and endovascular treatment. Of these, 21 (55%) patients underwent type I aortic arch hybrid debranching procedure and in 17 (45%) patients a type II aortic arch hybrid debranching procedure was performed. None of the patients were emergent. Results: No intra-operative deaths were recorded. In the type I aortic arch hybrid debranching patients' group, one patient died at home waiting the endovascular step, one developed ascending aortic dissection and another one developed a pseudoaneurysm at the site of the debranching at follow-up. In the type II aortic arch hybrid debranching patients' group, left carotid artery branch closure was detected at follow-up in one patient. Thirty day/in-hospital rates of adverse neurological events for both the surgical and endovascular procedures were 3% for minor stroke, with no permanent neurological deficit and 0% for permanent paraplegia/paraparesis. In 100% of the cases, the endovascular step succeeded and the type Ia endoleak rate was 0%. Conclusions: Hybrid arch surgery is a valuable option for aortic arch aneurysm treatment in patients with high surgical risk. The choice of aortic arch debranching between type I or type II is crucial and depends on anatomic and clinical patient characteristics. Further larger scale studies are needed to better define the advantages of these techniques.

Open supra-aortic revascularization and arch reconstruction after previous TEVAR in a complex arch anatomy.

We propose a technique to minimize the neurological and systemic risks involved in rerouting the blood flow toward the brain in a "single remaining vessel" configuration with a 90% stenosis by means of complete hypothermic cerebral protection associated with normothermic systemic blood flow with a "restitutio ad integrum" of the supra-aortic trunks flow. The perfusion of the brain and the arms was almost completely separated from the systemic perfusion by the deployment 1 year before of a thoracic endoprosthesis in association with complete chronic occlusion of the brachiocephalic trunk and a functioning carotid-subclavian bypass. The Free Flow of the prosthesis, which acted as a hook, moved the calcium toward the left carotid ostium, creating a 90% stenosis with intermittent acute cerebral hypoperfusion and amaurosis. We achieved an optimal result: The patient was discharged on postoperative day 7 with no neurological problems and with patency and direct blood flow in all the supra-aortic trunks.

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.

Optilene, a new non-absorbable monofilament is safe and effective for CABG anastomosis. OPTICABG - A prospective international, multi-centric, cohort study.

INTRODUCTION: Coronary artery bypass grafting (CABG) is performed to improve quality of life and to reduce cardiac-related mortality and morbidity in patients with coronary artery disease (CAD). The aim of the present observational study was to assess the performance of a new suture material (Optilene) for anastomosis construction in CABG surgery using a routine clinical procedure. Performance was assessed using the incidence of major adverse cardiac and cerebrovascular events (MACCE). METHODS: The study was designed as an international, multi-centre, prospective cohort study to evaluate the safety and efficacy of a new non-absorbable monofilament for CABG surgery compared to data published in a previous meta-analysis. Optilene suture was used to create the distal and proximal coronary artery anastomoses. The primary endpoint was the cumulative MACCE rate up to discharge. Secondary parameters were intraoperative handling of the suture material and QoL up to 3 months after surgery. Patients were examined 30 days and 3 months postoperatively. RESULTS: In total, 199 patients were enrolled in 3 centres in Europe. The cumulative CABG adverse event rate up to the day of discharge was 3%, in contrast to the 8.46% given by the data generated by Nalysnyk et al. A t-test showed that our CABG rate was significantly lower. QoL significantly increased from preoperatively until 3 months after surgery. Ease of handling the suture material was rated as very good. CONCLUSION: Optilene suture material represents a safe and effective alternative to existing sutures used in CABG surgery for anastomosis construction.

Modelling of Lesions Associated with Functional Mitral Regurgitation in an Ex Vivo Platform.

Functional mitral regurgitation (FMR) is a complex pathology involving valvular and subvalvular structures reconfiguration, and its treatment is considered challenging. There is a lack of experimental models allowing for reliable preclinical FMR treatments' evaluation in a realistic setting. A novel approach to simulate FMR was developed and incorporated into an ex vivo passive beating heart platform. FMR was obtained by dilating the mitral annulus (MA) mainly in the antero-posterior direction and displacing the papillary muscles (PMs) apically and laterally by ad hoc designed and 3D printed dilation and displacing devices. It caused hemodynamic and valve morphology alterations. Isolated MA dilation (MAD) led to significantly increased antero-posterior distance (A-P) and decreased coaptation height (CH), tenting area (TA) and systolic leaflets angulation, resembling clinically recognized type I of mitral regurgitation with normal leaflet motion. Whereas concomitant MAD with PM displacement caused an increase in A-P, TA, CH. This geometrical configuration replicated typical determinants of type IIIb lesion with restricted leaflet motion. The proposed methods provided a realistic and repeatable ex vivo FMR model featuring two lesions clinically associated with the pathology. It bears a promise to be successfully utilized in preclinical studies, clinical training and medical education.

A novel system for the treatment of aortic annular dilation: an ex vivo investigation.

OBJECTIVES: The main reason for aortic repair failures is recurrent annular dilatation. The fibrous portion of left ventricular outflow tract dilates. A novel device was designed to tackle this problem. METHODS: The device consists of an internal ring applied at the aortic annulus plus an external flexible band at the level of the aortic root. The internal ring has a semi-rigid portion (40%, placed at ventriculo-arterial junction) and a flexible portion to allow it to conform along the curves of the non-coronary/right coronary leaflet and right coronary/left coronary leaflet commissures. The external band acts as a reinforcement to the internal ring. A pulsatile mock loop capable of housing porcine aortic valve was used. Working conditions were 60 bpm of heart rate, 75 of stroke volumes and 120-80 mmHg of simulated pressure. Mean gradient, effective orifice area, annular diameter, coaptation height and length were recorded on 11 aortic root units (ARUs). High-speed video and standard echocardiographic images were also recorded. All data were acquired in the following conditions: (i) basal (untreated ARU); (ii) pathological condition (left coronary/non-coronary triangle was dilated by suturing an aortic patch); and (iii) ARU treated with the device. RESULTS: Gradients and effective orifice area were respectively 0.9 ± 0.64 mmHg and 3.1 ± 0.7cm2 (pathological) and 3.7 ± 1.1 mmHg and 1.5 ± 0.2cm2 (treated, P < 0.05). Left coronary/non-coronary diameter decreased from 2.4 ± 0.2 cm (pathological) to 2.0 ± 0.2 (treated, P < 0.05). Coaptation length and height were fully restored to basal values following treatment. Visual inspection showed proper dynamics of the leaflet, confirmed by high-speed video and echocardiography. CONCLUSIONS: The device allowed for restoring physiologic-like coaptation in the experimental model, without inducing clinically relevant worsening of the haemodynamics of the treated ARU.

Preoperative Computed Tomography Scan Analysis of Interleaflets Triangles to Guide Aortic Root Repair Procedures.

BACKGROUND: Stabilization of the ventriculo-aortic junction (VAJ) is gaining increasing interest in the context of aortic valve repair, since its dilation is a well-recognized risk factor for long-term repair failure. Interleaflets triangles are key elements of the VAJ, but cannot be completely visualized using echocardiography. A three-dimensional (3D) reconstruction of electrocardiogram-triggered computed tomography (CT) scan images allows an analysis of the real dimensions and anatomic characteristics of the subcommissural triangles. METHODS: A method was developed to visualize the interleaflets triangle at the CT-scan based on multiplanar post-processing reconstructions. Attention was focused on the triangles' apical angle evaluation. The data obtained with CT-scan reconstructions were compared with those collected in a previous post-mortem study to validate this measurement method. RESULTS: In the CT-scan group the angles between the left and right coronary sinuses, and the right non-coronary and left non-coronary sinuses were 46.23 ± 7.79°, 47.38 ± 6.97°, 45° [range: 42.75- 50.75°], respectively, and in the post-mortem group were 45.44 ± 12.39°, 48.31 ± 1218°, 50.25 ± 7.29°. No statistically significant differences between the two groups were identified (p = 0.84, 0.81, and 0.23). CONCLUSIONS: Based on experience acquired in the operating room, the acute-angle subcommissural triangles were considered normal, the equilateral triangles mildly dilated, and the obtuse triangles severely dilated. According to this classification, different reparative approaches were selected. A CTscan 3D reconstruction method, as validated by the present data, allows a preoperative evaluation of the triangles and VAJ in order to best plan a surgical reparative approach tailored to a single patient.

Comparison of the Performance of a Sutureless Bioprosthesis With Two Pericardial Stented Valves on Small Annuli: An In Vitro Study.

BACKGROUND: Aortic valve replacement has evolved recently with the development of the sutureless bioprosthesis. One such valve is the Perceval bioprosthesis, which is built by mounting leaflets of bovine pericardium to a thin stent; this approach has the potential to provide an excellent fluid dynamic performance. We undertook an in vitro study to compare the hydrodynamic performance of the sutureless bioprosthesis with two standard pericardial stented bioprostheses (Crown and Magna). METHODS: Tests were conducted using a mock loop, testing on two sizes of the three prostheses. The prosthesis sizes were chosen to house the valves in porcine aortic roots with a native annulus diameter of 19 mm (n = 6) or 21 mm (n = 6). The stroke volume ranged from 25 mL to 105 mL at a simulated heart rate of 70 beats per minute. RESULTS: Mean pressure drop and energy loss rose with increasing stroke volume in all of the valves tested (p < 0.001), with the sutureless valve showing the lowest values for both variables (p < 0.001). Effective orifice area values were stable across the stroke volume intervals and were larger in the sutureless valves (p < 0.001). CONCLUSIONS: All of the valves tested provided good fluid dynamic performances. The sutureless bioprosthesis provided the best performance with the least hindrance to flow behavior. From the hydrodynamic perspective, the sutureless prosthesis may present an advance in the evolution of bioprostheses, ensuring low gradients and potential for low incidence of patient-prosthesis mismatch even in small annuli.

Transcatheter Edge-to-Edge Treatment of Functional Tricuspid Regurgitation in an Ex Vivo Pulsatile Heart Model.

BACKGROUND: Although associated with left heart pathologies, functional tricuspid regurgitation (FTR) is often left untreated during left heart surgery. Hence, owing to its degenerative character, reoperation is often needed, encompassing an impressive (25% to 35%) mortality rate. Thus transcatheter approaches to FTR are raising great interest. OBJECTIVES: The authors evaluated the post-treatment effectiveness of the edge-to-edge technique using the percutaneous mitral valve repair device in an ex vivo pulsatile model of FTR. METHODS: The devices were implanted in 11 porcine hearts simulating FTR. In each heart, single-clip treatments involved grasping leaflet pairs in the medial or commissural position (6 combinations). Two-clip treatments were then performed considering all possible 15 combinations of leaflet pairs and medial/commissural grasping. Cardiac output, mean pulmonary pressure, and mean diastolic valve pressure gradient were evaluated in physiological and simulated pathological conditions (FTR), and post-treatments. RESULTS: Grasping the septal and anterior leaflets allowed for the best post-procedural outcome, ensuring a complete re-establishment of physiological-like hemodynamics. Septal and posterior grasping induced a significant recovery from FTR, although less marked. Conversely, grasping the anterior and posterior leaflets did not reduce FTR, and was detrimental in some specific cases. CONCLUSIONS: This experimental work demonstrated that the transcatheter edge-to-edge repair technique is a feasible approach for FTR. The study investigated this approach to develop a selective, specific structural intervention methodology for treating FTR, considering the several biomechanical factors that alter proper functionality of valvular substructures. These results can be used to guide the development of edge-to-edge repair techniques in treatment of FTR.

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.

Reimplantation Technique: A New Approach to Increase Aortic Valve Coaptation.

The reimplantation technique is one of the most popular valve-sparing procedures. Previously published in-vitro studies have demonstrated the success of the aortic interleaflets triangle reshaping approach in increasing the coaptation surface. An alternative positioning of the pledgeted stitches used in the proximal suture line of the David operation is proposed to simultaneously stabilize the annulus and improve the valve functional reserve in case of annulo-aortic ectasia due to dilation of the interleaflet triangles.

In vitro study of a standardized approach to aortic cusp extension.

PURPOSE: Cusp extension technique (CET) is a reparative surgical procedure for restoring aortic valve function by suturing patches to the compromised native leaflets. Its outcomes are strongly dependent on the ability of the surgeon. We proposed and tested a novel approach on an in vitro model, aimed at standardizing and simplifying the surgical procedure. METHODS: A set of standard pre-cut bovine pericardium patches, available in different sizes, was developed. The surgeon can choose the leaflet-specific patches to be implanted according to the patient anatomy, using a geometrical model of the aortic valve whose inputs are the measured intercommissural distances. The hemodynamic performance of this approach was evaluated on porcine aortic roots in a pulsatile mock loop. Hydrodynamic and kinematic evaluation of the samples was provided. RESULTS: After CET, mean and maximum pressure drops were 3.1±1.3 mmHg and 25.4±5.0 mmHg respectively, and EOA was 3.8±0.8 cm. CONCLUSIONS: Our approach to cusp extension proved to be reliable and effective in restoring valve functioning, without significantly altering the physiological kinematics. The use of pre-cut patches considerably simplified the surgery, increasing standardization and repeatability.

In-vitro study of a porcine quadricuspid aortic valve.

BACKGROUND AND AIM OF THE STUDY: Quadricuspid aortic valve (QAV) is an extremely rare congenital defect in which the valve features an additional fourth cusp. It is often associated with an alteration in valve functionality such as valve regurgitation, stenosis and coronary disease. These associated pathologies entail surgical correction in about 50% of patients at a mean age of 50 years. METHODS: A swine QAV was studied in a pulsatile mock loop in the laboratory. Rest (70 bpm) and exercise (100 bpm) conditions were simulated, and opening and closing kinematics were evaluated from a high-speed video. Short- and long-axis echocardiograms were recorded. The pressure drop across the valve, valve competence and effective orifice area were evaluated and compared to data from healthy samples tested in the same experimental apparatus. RESULTS: Hemodynamic quantities were physiologic-like, despite the QAV showing an altered kinematics (longer closing and opening times compared to healthy samples) and an asynchronous closing phase (the extra cusps reached the closed configuration at the end of systole systematically earlier with respect to the other three cusps). Echocardiographic data showed an increased coaptation height between the left and right coronary cusps, and a mismatch between the lunule of the extra cusp and the non-coronary cusp. CONCLUSION: The altered kinematics, together with incorrect coaptation, can alter the biomechanics of the structure, inducing an anomalous distribution of local stress which could lead to structural failure over time.