Historical evolution of robot-assisted cardiac surgery: a 25-year journey.

Many patients and surgeons today favor the least invasive access to an operative site. The adoption of robot-assisted cardiac surgery has been slow, but now has come to fruition. The development of modern surgical robots took surgeons close collaboration with mechanical, electrical, and optical engineers. Moreover, the necessary project funding required entrepreneurs, federal grants, and venture capital. Non-robotic minimally invasive cardiac surgery paved the way to the application of surgical robots by making changes in operative approaches, instruments, visioning modalities, cardiopulmonary perfusion techniques, and especially surgeons' attitudes. In this article, the serial development of robot-assisted cardiac surgery is detailed from the beginning and through clinical application. Included are references to the historical and most recent clinical series that have given us the evidence that robot-assisted cardiac surgery is safe and provides excellent outcomes. To this end, in many institutions these procedures now have become a new standard of care. This evolution reflects Sir Isaac Newton's famous 1676 quote when referring to Rene Descartes, "If have seen further [sic] than others, it is by standing on the shoulders of giants".

Initial in-human experience with the conveyor cardiovascular system for the delivery of large profile transcatheter valve devices.

OBJECTIVES: To determine the safety and efficacy of the conveyor cardiovascular system (CCS) to facilitate the delivery of large profile transcatheter valve devices. BACKGROUND: Transcatheter valve devices rely on force provided by the operator to be delivered to their intended position. This delivery may be challenging in a variety of anatomic scenarios. The ability to provide steering from the tip of the device by forming an arterial venous loop may help overcome these challenges. METHODS: Between May, 2019 and October, 2020, five patients were recruited for delivery of transcatheter valve devices with the CCS. These patients were deemed by the operators to have challenging anatomy which could make conventional valve delivery difficult or impossible. These patients were recruited as part of an FDA approved early feasibility study or through an institutional review board approved compassionate use protocol. RESULTS: Three patients underwent transcatheter mitral valve replacement with a SAPIEN-3 valve. One patient each underwent transcatheter aortic valve (TAVR) implantation with a SAPIEN 3 and 1 patient underwent TAVR implantation with a Lotus valve. All patients underwent successful implantation of the valve and removal of the CCS and valve delivery systems. There was no more than trivial mitral regurgitation post procedure in any patient and there was no more than trivial paravavular leak. There were no major in-hospital complications. CONCLUSIONS: The CCS facilitates the delivery of large profile transcatheter valve devices in challenging anatomic scenarios. Further studies are needed with additional valve technologies.

Comparative differences of mitral valve-in-valve implantation: A new mitral bioprosthesis versus current mosaic and epic valves.

OBJECTIVE: Evaluate transcatheter mitral valve replacement (TMVR) valve-in-valve (VIV) outcomes in three different mitral bioprostheses (of comparable measured internal diameters) under stable hemodynamic and surgical conditions by bench, echocardiographic, computerized tomography (CT), and autopsy comparisons pre- and post-valve implantation in a porcine model under matched controlled conditions. BACKGROUND: Impact of surgical bioprosthesis design on TMVR VIV procedures is unknown. METHODS: Fifteen similar-sized Yorkshire pigs underwent pre-procedural CT screening. Twelve had consistent anatomic features and underwent implantation of mitral bioprostheses. Four valves from each of three manufacturers were implanted in randomized fashion: 27-mm Epic, 27-mm Mosaic, and 25-mm Mitris, followed by TMVR VIV with 26 Edwards Sapien3. Post-VIV, suprasternal TEE studies were performed to assess hemodynamic function, followed by a gated contrast CT. After euthanasia, animals underwent necropsy for anatomic evaluation. RESULTS: All 12 animals had successful VIV implantation with no study deaths. The post vivMitris (3.77 ± 0.36)/(2.2 ± 0.25 mmHg) had the lowest peak/mean trans-mitral gradient and the vivEpic the highest (15.5 ± 2.55)/(7.09 ± 1.13 mmHg). All THVs (transcatheter heart valves) had greatest deformation within the center of the THV frame; with the smallest waist opening area in the vivEpic (329 ± 35.8 mm2 ) and greatest in the vivMitris (414 ± 33.12 mm2 ). Bioprosthetic frames without obvious radiopaque markers resulted in the most ventricular implantation of the THV's anteroseptal frame (Epic: -4.52 ± 0.76 mm), versus the most radiopaque bioprosthesis (Mitris: -1.18 ± 2.95 mm), and higher peak LVOT gradients (Epic: 4.82 ± 1.61 mmHg; Mitris: 2.91 ± 1.47 mmHg). CONCLUSIONS: The current study demonstrates marked variations in hemodynamics, THV opening area, and anatomic dimensions among measured similarly sized mitral bioprostheses. These data suggest a critical need for understanding the potential impact of variations in bioprosthesis design on TMVR VIV clinical outcomes.

Impact of Anchor Location on Mitral Neochordae Forces: An In Vitro Study.

PURPOSE: This study examined changes in force distribution between the neochordae corresponding to different ventricular anchor locations. DESCRIPTION: Seven porcine mitral valves were mounted in a left heart simulator. Neochordae (expanded polytetrafluoroethylene) originated from either a simulated left ventricular apex, papillary muscle base, or papillary muscle tip location. The neochordae were attached at three sites along the P2 leaflet segment: P2Lateral; P2Center, and P2Medial. Mitral regurgitation was induced by cutting posterior leaflet P2 marginal chordae. The forces on each neochord required to restore normal mitral valve coaptation were quantified for different ventricular anchoring origins and leaflet insertion sites. EVALUATION: The results showed that under both normotensive and hypertensive conditions, the force exerted was much higher at P2Center than either P2Lateral or P2Medial, independent of ventricular anchor location. Also, forces on both P2Lateral and P2Medial were not statistically different. CONCLUSIONS: Artificial neochordae treatment for all anchoring locations was effective in correcting induced mitral regurgitation. The P2 central neochordae had a significantly higher force than both lateral neochords under all conditions.

Comparison of a new bioprosthetic mitral valve to other commercially available devices under controlled conditions in a porcine model.

BACKGROUND/AIM: To evaluate three mitral bioprostheses (of comparable measured internal diameters) under controlled, stable, hemodynamic and surgical conditions by bench, echocardiographic, computerized tomography and autopsy comparisons pre- and postvalve implantation. METHODS: Fifteen similar-sized Yorkshire pigs underwent preprocedural computerized tomography anatomic screening. Of these, 12 had consistent anatomic features and underwent implantation of a mitral bioprosthesis via thoracotomy on cardiopulmonary bypass (CPB). Four valves from each of three manufacturers were implanted in randomized fashion: 27-mm Epic, 27-mm Mosaic, and 25-mm Mitris bioprostheses. After CPB, epicardial echocardiographic studies were performed to assess hemodynamic function and define any paravalvular leaks, followed by postoperative gated contrast computerized tomography. After euthanasia, animals underwent necropsy for anatomic evaluation. RESULTS: All 12 animals had successful valve implantation with no study deaths. Postoperative echocardiographic trans-valve gradients varied among bioprosthesis manufacturers. The 25-mm Mitris (5.1 ± 2.7)/(2.6 ± 1.3 torr) had the lowest peak/mean gradient and the 27-mm Epic bioprosthesis had the highest (9.2 ± 3.7)/(4.6 ± 1.9 torr). Surgical valve opening area (SOA) varied with the 25-mm Mitris having the largest SOA (2.4 ± 0.15 cm2 ) followed by the 27-mm Mosaic (2.04 ± 0.23 cm2 ) and the 27-mm Epic (1.8 ± 0.27 cm2 ) valve. Bench device orthogonal internal diameter measurements did not match manufacturer device size labeling: 25-mm Mitris (23 × 23 mm), 27-mm Mosaic (23 × 22 mm), 27-mm Epic (21 × 21 mm). CONCLUSIONS: Current advertisement/packaging of commercial surgical mitral valves is not uniform. This study demonstrates marked variations in hemodynamics, valve opening area and anatomic dimensions between similar sized mitral bioprostheses. These data suggest a critical need for standardization and close scientific evaluation of surgical mitral bioprostheses to ensure optimal clinical outcomes.

Reoperative, transapical off-pump neochordae implantation for recurrent degenerative mitral regurgitation resulting from a newly ruptured native chord.

Transapical mitral valve repair with NeoChord implantation is effective and safe to replace ruptured chordae due to degenerative disease. Redo transapical neochordae implantation has never been reported in the literature. We present a case report of a 53-year-old man who underwent a reoperative neochord implantation for recurrent severe mitral regurgitation, resulting from degenerative disease progression with a new native chordal rupture. We report the midterm durability of reoperative Neochord repair.

The EACTS simulation-based training course for endoscopic mitral valve repair: an air-pilot training concept in action.

OBJECTIVES: We have developed a high-fidelity minimally invasive mitral valve surgery (MIMVS) simulator that provides a platform to train skills in an objective and reproducible manner, which has been incorporated in the European Association for Cardiothoracic Surgery (EACTS) endoscopic mitral valve repair course. The aim of the study is to provide data on the application of simulation-based training in MIMVS using an air-pilot training concept. METHODS: The 2-day EACTS endoscopic mitral training course design was based on backwards chaining, pre- and post-assessment, performance feedback, hands-on training on MIMVS, theoretical content and follow-up. One hundred two participants who completed the full programme throughout 2016-2018 in the EACTS endoscopic mitral training courses were enrolled in the current study. RESULTS: Of the 102 participants, 83 (83.3%) participants were staff/attending surgeons, 12 (11.8%) participants had finished residency and 5 (4.9%) participants were residents. Theoretical pre- and post-assessment showed that participants scored significantly higher on post-assessment (median score 58% vs 67%, P < 0.001). Pre- and post-assessment of skills on MIMVS showed that participants could work with long-shafted instruments more accurately (suture accuracy 43% vs 99%, P < 0.001) and faster (87 vs 42 s, P < 0.001). Follow-up, based on course evaluation and a survey, had a response rate of 55% (57 participants). Of all surveyed participants, 33.3% (n = 19) had started an endoscopic mitral programme successfully, while 66.7% (n = 38) did not yet start. CONCLUSIONS: The MIMVS is a valuable tool for the development and assessment of endoscopic mitral repair skills. This EACTS course provides surgeons with theoretical knowledge and necessary skills to start an endoscopic mitral valve programme successfully.

A propensity matched analysis of robotic, minimally invasive, and conventional mitral valve surgery.

OBJECTIVES: Institutional studies suggest robotic mitral surgery may be associated with superior outcomes. The objective of this study was to compare the outcomes of robotic, minimally invasive (mini), and conventional mitral surgery. METHODS: A total of 2300 patients undergoing non-emergent isolated mitral valve operations from 2011 to 2016 were extracted from a regional Society of Thoracic Surgeons database. Patients were stratified by approach: robotic (n=372), mini (n=576) and conventional sternotomy (n=1352). To account for preoperative differences, robotic cases were propensity score matched (1:1) to both conventional and mini approaches. RESULTS: The robotic cases were well matched to the conventional (n=314) and mini (n=295) cases with no significant baseline differences. Rates of mitral repair were high in the robotic and mini cohorts (91%), but significantly lower with conventional (76%, P<0.0001) despite similar rates of degenerative disease. All procedural times were longest in the robotic cohort, including operative time (224 vs 168 min conventional, 222 vs 180 min mini; all P<0.0001). The robotic approach had comparable outcomes to the conventional approach except there were fewer discharges to a facility (7% vs 15%, P=0.001) and 1 less day in the hospital (P<0.0001). However, compared with the mini approach, the robotic approach had more transfusions (15% vs 5%, P<0.0001), higher atrial fibrillation rates (26% vs 18%, P=0.01), and 1 day longer average hospital stay (P=0.02). CONCLUSION: Despite longer procedural times, robotic and mini patients had similar complication rates with higher repair rates and shorter length of stay metrics compared with conventional surgery. However, the robotic approach was associated with higher atrial fibrillation rates, more transfusions and longer postoperative stays compared with minimally invasive approach.

Permanent Pacemaker Implantation After Rapid Deployment Aortic Valve Replacement.

BACKGROUND: Expandable, rapid deployment aortic valves may interfere with the cardiac conduction system, which can lead to permanent pacemaker implantation (PPI). We sought to characterize PPI after rapid deployment aortic valve replacement with the Edwards Intuity valve system (Edwards Lifesciences, Irvine, CA) and investigate associated factors. METHODS: We analyzed 708 patients from 29 centers in the Multicenter Experience With Rapid Deployment Edwards Intuity Valve System for Aortic Valve Replacement (TRANSFORM) trial undergoing rapid deployment aortic valve replacement with or without coronary artery bypass graft surgery without preexisting pacemakers. Intrinsic conduction status was recorded as well as PPI incidence through 1 year. The PPI indications were categorized based on expert review of patient PPI source documents. Multivariate analysis was conducted to identify characteristics associated with PPI. RESULTS: After rapid deployment aortic valve replacement, the PPI incidence through 30 days (PPI30) was 13.6%, with 10.9% due to atrioventricular block. In the 423 of 708 patients (59.7%) without any baseline conduction abnormalities, all-cause PPI30 was 8%, 5% for atrioventricular block. For PPIs inserted before discharge, the median time to PPI was 5 days, with 22% placed within 48 hours. Independent predictors of PPI30 were baseline right bundle branch block (odds ratio 7.35, p < 0.0001), female gender (2.62, p = 0.004), larger valve size (1.20, p = 0.016), and atrioventricular block (1.80, p = 0.062). Subset analysis revealed a greater than twofold difference in PPI30 among the largest enrolling centers. CONCLUSIONS: Patient factors associated with PPI after rapid deployment aortic valve replacement were right bundle branch block, atrioventricular block, female gender, and larger valve size. Interestingly, a strong center-level effect was associated with PPI. This effect may reflect differences in practice patterns, such as postoperative drug management or timing to PPI. These findings provide a deeper understanding of PPI after rapid deployment aortic valve replacement and help guide clinical practice and patient management.

Step-by-Step Aortic Valve Replacement With a New Rapid Deployment Valve.

PURPOSE: Rapid deployment/sutureless aortic valve replacement is aimed at minimizing the invasiveness of surgical aortic valve replacement. We describe the implantation techniques of a new rapid deployment aortic valve, focusing on its unique and challenging features. DESCRIPTION: The EDWARDS INTUITY Elite aortic valve (Edwards Lifesciences, Irvine, CA) represents a hybrid between the surgical PERIMOUNT Magna Ease (Edwards Lifesciences) pericardial valve, but with advanced features of the percutaneous SAPIEN valve system (Edwards Lifesciences). A flexible delivery system, with a balloon-expandable subannular frame, facilitates insertion. Important implantation steps include an extended oblique "hockey-stick" aortotomy, symmetrical annular debridement, intra-annular and supra-annular sizing, guiding suture placement, and balloon expansion of the subannular valve frame. EVALUATION: Although this valve provides advantages over conventional aortic valves, its implantation is unique, and special operative considerations must be heeded for optimal outcomes. Implantation requires minimal suturing, enabling smaller incisions. Also, the intra-annular inflow frame may promote improved hemodynamics. CONCLUSIONS: The INTUITY Elite system represents a significant innovation in bioprosthesis technology. It has been shown to be safe and effective, but its implantation requires detailed attention to several unique operative steps.