"The Starry Sky." A new intraprocedural three-dimensional echocardiographic technique.

The NeoChord procedure is a micro-invasive, trans-ventricular, beating-heart chordal replacement technique for patients with severe degenerative mitral valve regurgitation resulting from prolapsed or flail leaflets. Three dimensional transoesophageal echocardiographic guidance is crucial to assist the operator during the procedure. Equidistant placement of neochordae along the free edge of the prolapsing leaflet segment is important to ensure uniform stress distribution and to avoid damaging any of the previously placed neochordae. Lowering the image gain associated with the three-dimensional surgical view of the mitral valve allows for signal attenuation of the native structures delineating the precise placement location of the neochordae.

A novel percutaneous solution to limb ischemia due to arterial occlusion from a femoral artery ECMO cannula.

PURPOSE: To describe a novel percutaneous technique for distal limb perfusion in the face of femoral artery occlusion secondary to extracorporeal membrane oxygenation (ECMO) cannula placement. TECHNIQUE: The technique is described in a 59-year-old man who presented with an inferior wall myocardial infarction and a large ventricular septal defect (VSD) requiring the initiation of ECMO via right femoral artery and vein cannulae. He subsequently developed right lower limb ischemia secondary to cannula occlusion of the femoral artery. Percutaneous transfemoral placement of a flush catheter in the right common femoral artery was performed angiographically. Ischemic symptoms resolved, and the patient was subsequently able to undergo repair of his VSD without any further lower limb ischemic sequelae. CONCLUSION: Percutaneous transfemoral placement of a flush catheter in the common femoral artery distal to ECMO cannula insertion has not to our knowledge been reported and carries the added benefit of restoring perfusion to both superficial and profunda femoris arteries.

Transcatheter Mitral Valve Chordal Repair: Current Indications and Future Perspectives.

Transcatheter Mitral Valve Repair (TMVRe) technologies constitute a rapidly expanding field, and have the potential of being adopted as a valuable alternative to surgery in selected patients. TMVRe devices can be distinguished depending on the targeted part of the Mitral Valve (MV) apparatus. Standard classification includes leaflet repair, direct/indirect annuloplasty, chordal repair, and ventricular/chamber remodeling devices. We present the current device situation on chordal repair technologies. Nowadays, transapical off-pump beating heart chordal implantation procedure has become a safe and reproducible option for Degenerative Mitral Regurgitation (DMR). Besides the truly minimally-invasiveness of the procedure, another unique advantage offered by a beating-heart chordal implantation is the real-time assessment of chordal length adjustment during heart cycle with a normally filled left ventricle. Currently, one system is commercially available in Europe, the NeoChord DS 1000 (NeoChord, Inc., St. Louis Park, MN) and the Harpoon TDS-5 (Edwards Lifesciences, Irvine, CA) should become available soon. There is also a diffuse and strong interest to move from a transapical procedure toward a fully transcatheter (transfemoral and transeptal) procedure as shown by the increased number of preclinical programs under development. Interestingly, to achieve outcomes that equate to those of open surgery in DMR, transcatheter therapies will need to follow rigid indications due to strict patient selection criteria for each device, or adopt multiple techniques in a single repair procedure for complex MV disease. Continuous analysis of current clinical results together with future dedicated trial will be of extreme importance to foster the new and upcoming field of transcatheter MV therapy technology development.

The dynamic cardiac biosimulator: A method for training physicians in beating-heart mitral valve repair procedures.

OBJECTIVE: Previously, cardiac surgeons and cardiologists learned to operate new clinical devices for the first time in the operating room or catheterization laboratory. We describe a biosimulator that recapitulates normal heart valve physiology with associated real-time hemodynamic performance. METHODS: To highlight the advantages of this simulation platform, transventricular extruded polytetrafluoroethylene artificial chordae were attached to repair flail or prolapsing mitral valve leaflets. Guidance for key repair steps was by 2-dimensional/3-dimensional echocardiography and simultaneous intracardiac videoscopy. RESULTS: Multiple surgeons have assessed the use of this biosimulator during artificial chordae implantations. This simulation platform recapitulates normal and pathologic mitral valve function with associated hemodynamic changes. Clinical situations were replicated in the simulator and echocardiography was used for navigation, followed by videoscopic confirmation. CONCLUSIONS: This beating heart biosimulator reproduces prolapsing mitral leaflet pathology. It may be the ideal platform for surgeon and cardiologist training on many transcatheter and beating heart procedures.

Off-Pump NeoChord Mitral Valve Repair to Simultaneously Treat Posterior Leaflet Prolapse and Systolic Anterior Motion.

This case represents the first report of complete elimination of systolic anterior motion by beating-heart implantation of artificial chordae tendineae on a prolapsing and redundant posterior leaflet.

Transapical off-pump mitral valve repair. First experience with the NeoChord system in Poland (report of two cases).

BACKGROUND: Artificial chord implantation to repair a flail or prolapsing mitral valve leaflet requires open heart surgery and cardiopulmonary bypass. AIM: Transapical off-pump artificial chordae implantation is a new surgical technique proposed to treat degenerative mitral valve regurgitation. The procedure is performed using the NeoChord DS1000 system (NeoChord, Inc., St. Louis Park, MN, USA), which facilitates both implantation and lenght adjustment of the artificial chordae under two (2D)- and three (3D)-dimensional transoesophageal echocardiographic (TEE) guidance on a beating heart. METHODS: Two male patients aged 60 and 55 years with severe mitral regurgitation due to posterior leaflet prolapse underwent transapical off-pump artificial chordae implantation on September 3, 2015. The procedure was performed by left minithoracotomy under general anaesthesia in a cardiac surgical theatre, using 2D and 3D TEE guidance. RESULTS: Early procedural success as confirmed by 3D TEE was achieved in both patients, with implantation of 6 artificial chordae in the first patient and 3 artificial chordae in the second patient. Both procedures were uneventful, and no postoperative complications were noted. The patients were discharged home on the 8th and 6th postoperative day, respectively. CONCLUSIONS: The NeoChord DS1000 system allows both implantation and lenght adjustment of artificial chordae under 2D and 3D TEE guidance on a beating heart. Our initial experience in 2 patients with posterior mitral leaflet prolapse indicates that the procedure is feasible and safe.

"The balloon plug concept" for tricuspid valve repair: ex vivo proof of concept.

OBJECTIVE: Functional tricuspid regurgitation (TR) is recognized as a significant cause of morbidity and mortality in cardiothoracic surgery. We hypothesized that a variably expandable, transvalvular balloon mounted on a catheter could be percutaneously inserted and fixed to the right ventricle apex. This novel approach could provide a minimally invasive way to eliminate clinically relevant TR caused by annular dilatation. This study was performed to test the ex vivo hemodynamic effects and the feasibility of the "balloon plug concept." METHODS: Twenty harvested calf tricuspid valves were placed in a mechanical simulator. Tricuspid regurgitation was created by annular stretching and displacement of the papillary muscles so as to create central TR. A flexible catheter with a 4-cm-long, soft, fusiform balloon was positioned across the valve so that the balloon was suspended centrally across the valve annular plane. After activating the mechanical ventricle, data were collected with balloon inflation volumes of saline from 5 to 20 mL. Transvalvular pressure gradients and leaflet mechanics were evaluated with incremental inflation. RESULTS: In all cases, 5-mL inflation did not significantly reduce TR and 20-mL inflation caused obstruction to antegrade flow (mean transvalvular gradient > 4 mm Hg). Inflation between 10 and 15 mL caused significant reduction in TR with acceptable transvalvular gradients (<3 mm Hg). CONCLUSIONS: The balloon plug concept showed promising ex vivo hemodynamic results. In vivo investigations are warranted to evaluate percutaneous techniques, thrombogenicity, and effects of repeated balloon-leaflet contact on valve integrity.

Hemostatic effects of tranexamic acid in elective thoracic aortic surgery: a prospective, randomized, double-blind, placebo-controlled study.

OBJECTIVE: We studied the hemostatic effects of tranexamic acid in patients undergoing elective surgery involving the thoracic aorta. METHODS: In a double-blind, randomized fashion, 60 consecutive patients were assigned to two treatment groups: 30 patients (placebo group) received infusion of saline solution, and 30 (treatment group) received tranexamic acid (1 g before skin incision, an infusion of 400 mg/h during the operation, and 500 mg in the pump priming). Perioperative bleeding was considered as a primary outcome. Perioperative allogeneic transfusions, major thrombotic complications (myocardial infarction, pulmonary embolism, renal insufficiency), and surgical outcomes were also considered. RESULTS: Patients treated with tranexamic acid showed significant reductions in postoperative bleeding, both in terms of the amount collected during the first 4 postoperative hours (median 307 mL, interquartile range 253-361 mL in the placebo group vs median 211 mL, interquartile range 108-252 mL in the treatment group, P =.002) and in terms of total bleeding (median 722 mL, interquartile range 574-952 mL in the placebo group vs median 411 mL, interquartile range 313-804 mL in the treatment group, P =.04). Consequently, the number of patients transfused differed significantly between groups (21 patients [72.4%] in the placebo group vs 13 [44.8%] in the treatment group, P =.033). Patients in the treatment group showed significant reductions in the total amount for the entire group of packed red cells transfused (13,500 mL in the treatment group vs 28,000 mL in the placebo group, P =.012) and in the total amount of allogeneic transfusions (23,400 mL in the treatment group vs 53,000 mL in the placebo group, P =.024). No differences in perioperative thrombotic complications were found. CONCLUSIONS: In this initial series of patients undergoing thoracic aortic surgery, tranexamic acid appeared effective in reducing perioperative bleeding, with a significant reduction in the need for allogeneic transfusions and without any increased risk of thrombotic complications.

Beating-heart, off-pump mitral valve repair by implantation of artificial chordae tendineae: an acute in vivo animal study.

OBJECTIVE: To evaluate the effectiveness of a new off-pump mitral valve repair technology in restoring valve competency in a porcine model of acute mitral regurgitation. METHODS: Acute mitral regurgitation was induced in 6 anesthetized pigs by cutting anterior leaflet chordae. Artificial chordae were then transapically implanted on the prolapsing segment under epicardial echocardiographic guidance and secured outside the left ventricular apex. All intracardiac manipulations were performed off-pump, through a stab wound incision on the left ventricular apex. RESULTS: Cutting the anterior leaflet chordae caused an eccentric, posteriorly directed jet of mitral regurgitation that could be visualized by color Doppler sonography. Implantation of chordae through the left ventricular apex completely eliminated valve regurgitation in 4 animals and reduced regurgitation in 2. Intraoperative measurement of artificial chordal tensions gave similar values to those reported for native chordae. CONCLUSIONS: Off-pump, transapical implantation of artificial chordae between a prolapsing anterior mitral valve leaflet and the left ventricular apex was effective in reducing acutely induced mitral regurgitation. Long-term studies are planned to assess the stability in this animal model.

Transapical off-pump removal of the native aortic valve: a proof-of-concept animal study.

OBJECTIVE: This study evaluates the feasibility of off-pump native aortic valve removal in preparation for transapical aortic valve replacement. Off-pump aortic valve replacement is performed by balloon predilatation of the native valve followed by insertion of a stented prosthesis. In patients with calcified annuli and cusps, particulate embolization, suboptimal prosthesis sizing, and perivalvular leaks may occur. Therefore, native valve removal may improve outcomes after transapical aortic valve replacement. METHODS: The aortic cusps were sequentially removed from 10 pigs in an off-pump procedure. A temporary valve was inserted percutaneously into the ascending aorta to prevent aortic regurgitation. The electrocardiogram, coronary blood flow, and arterial, left atrial, and ventricular pressures were continuously monitored. RESULTS: Removal of the aortic cusps caused a drop in diastolic arterial pressure and its equalization with left ventricular diastolic pressure. Systolic pressure decreased by 13.5%. Left atrial pressure increased by 86.0%. Coronary blood flow decreased by 39.9% and its pattern changed from mostly diastolic to mostly systolic. Electrocardiographic signs of ischemia appeared almost immediately. Percutaneous insertion of a temporary valve in the ascending aorta increased diastolic pressure and caused a tendency toward echocardiographic normalization. CONCLUSIONS: Aortic valve removal in a healthy beating heart causes acute massive aortic regurgitation, hemodynamic instability, and the rapid onset of myocardial ischemia. Reduction of left ventricular volume overload, by placement of a temporary valve in the ascending aorta, mitigates myocardial distress, helps stabilize hemodynamic parameters, and may be a useful tool to allow surgical manipulations of the aortic valve and annulus during transapical aortic valve replacement procedures.

In vitro testing of a temporary catheter-based aortic "parachute" valve.

Recently developed technologies allow aortic valve implantation off-pump in a beating heart. In this procedure, the native, stenotic aortic valve is not removed, but simply crushed by a pressure balloon mounted on a percutaneous catheter. Removal of the native aortic cusps before valve replacement may reduce the incidence of annular or cuspal calcium embolization and late perivalvular leaks and increase implantable valve size. However, a temporary valve system in the ascending aorta may be necessary to maintain hemodynamic stability by reducing acute aortic regurgitation and left ventricular volume overload. This study evaluates the hemodynamic effects of a wire-mounted, monoleaflet, temporary valve apparatus in a mechanical cardiovascular simulator. Aortic flow, systemic pressure and left ventricular pressure were continuously monitored. An intraluminal camera obtained real-time proximal and distal images of the valve in operation. Insertion of the parachute valve in the simulator increased diastolic pressure from 7 to 38 mm Hg. Cardiac output increased from 2.08 to 4.66 L/min and regurgitant volume decreased from 65 to 23 mL. In conclusion, placement of a temporary valve in the ascending aorta may help maintain hemodynamic stability and improve off-pump aortic valve replacement.

Tension measurement of artificial chordae tendinae implanted between the anterior mitral valve leaflet and the left ventricular apex: an in vitro study.

OBJECTIVE: : A newly developed surgical technique allows implantation of artificial chordae tendinae between a mitral valve leaflet and the left ventricular (LV) apex in a closed-chest, off-pump mitral valve repair operation. However, this orientation causes tension vectors on the mitral valve leaflet in a different direction than those of native chordae. The purpose of this study was to investigate the relationship between systolic LV pressure and the tension of artificial chordae secured at the ventricular apex to assess if the altered tension vectors on the mitral leaflet resulted in excessive stress on the chordae/leaflet system. METHODS: : Freshly harvested porcine mitral valves were suspended in a mechanical LV simulator. Two 5-0 Gore-Tex sutures were secured to the free edge of the middle scallop of the anterior leaflet adjacent to the insertion point of two major native chordae. The native chordae were then cut. A simulator pump was activated at different pressure levels, and the tension of the artificial chordae was measured with a digital tensiometer during several cardiac cycles. RESULTS: : The numerical relationship between chordal tension (in Newtons, N) and LV pressure (in mm Hg/100) averaged at 0.8 (range 0.6-1.05). This tension/pressure relationship was similar in order of magnitude and range to that measured in native chordae in previously published studies. CONCLUSIONS: : In this in vitro model, orienting artificial chordae in a direction mimicking implantation between the valve and the LV apex does not result in excessive tension stress on either the chordae or the mitral leaflet.

Intraoperative low-volume acute normovolemic hemodilution in adult open-heart surgery.

BACKGROUND: Recently, various studies have questioned the efficacy of intraoperative acute normovolemic hemodilution (ANH) in reducing bleeding and the need for allogeneic transfusions in cardiac surgery. The aim of the present study was to reevaluate the effects of a low-volume ANH in elective, adult open-heart surgery. METHODS: Two hundred four consecutive adult patients undergoing cardiac surgery were prospectively randomized in a nonblinded manner into two groups: ANH group (103 patients), where 5-8 ml/kg of blood was withdrawn before systemic heparinization and replaced with colloid solutions, and a control group, where no hemodilution was performed (101 patients). Procedures included single and multiple valve surgery, aortic root surgery, coronary surgery combined with valve surgery, or partial left ventriculectomy. The purpose of the study was to evaluate the efficacy of ANH in reducing the need for allogeneic blood components. Routine hematochemical evaluations, perioperative blood loss, major complications, and outcomes were also recorded. RESULTS: No differences were found between the groups regarding demographics, baseline hematochemical data, and operative characteristics. There was no difference in the amount of transfusions of packed red cells, fresh frozen plasma, platelet concentrates, total number of patients transfused (control group, 36% vs. ANH group, 34.3%; P = 0.88), and amount of postoperative bleeding (control group, 412 ml [313-552 ml] vs. ANH group, 374 ml [255-704 ml]) (median [25th-75th percentiles]); P = 0.94. Further, perioperative complications, postoperative hematochemical data, and outcomes were not different. CONCLUSIONS: In patients undergoing elective open-heart surgery, low-volume ANH showed lack of efficacy in reducing the need for allogeneic transfusions and postoperative bleeding.