The learning curve of robotic coronary arterial bypass surgery: A report from the STS database

Robotic Assisted Minimally Invasive Coronary Revascularisation: Midterm Results

BACKGROUND

Robotic assistance has many advantages in minimally invasive coronary bypass surgery, such as the harvest of a longer portion of the LIMA in addition to the avoidance of sternotomy, thus offering a less invasive approach for multivessel revascularisation. We present the midterm clinical outcomes of robotic-assisted minimally invasive coronary bypass (RA-CABG) cases at our centre.

METHODS

One hundred and fifty consecutive patients who underwent RA-CABG with preoperative computed tomography angiography guidance were studied. Robotic LIMA harvesting was performed. The main outcome measure of the study was the midterm survival and incidence of major adverse cardiovascular events (MACE) up to 5 years.

RESULTS

The median follow-up was 19.8 months. In the Kaplan-Meier survival analysis, 1-year survival was 99.1% and 5-year survival was 97.5%. 1-year freedom from MACE was 97.3% and 5-year freedom from MACE was 95%.

CONCLUSIONS

Robotic-assisted minimally invasive coronary bypass surgery has safe midterm outcomes and can be performed with excellent results.

Patient complexity does not affect surgical learning curve and clinical outcomes during early experience in robotic assisted coronary surgery

Adoption of robot-assisted coronary artery bypass grafting (RA-MIDCAB) remains limited due to concerns about learning curves, outcomes, and patient-specific anatomic challenges. This study evaluates our initial single-center experience with RA-MIDCAB. Between December 2022 and June 2024, 52 patients underwent RA-MIDCAB. Inclusion criteria comprised isolated left anterior descending artery (LAD) stenosis or LAD revascularization as part of a hybrid valvular/coronary strategy. Primary endpoints were 30-day mortality, conversion to sternotomy, and graft injury. Operative times and biometric indices (body indices such as body mass index [BMI], Haller Index, and Cardiothoracic Ratio) were analyzed for correlation with learning curve progression and surgical outcomes. Mean age was 68.5 ± 11.5 years, and 82.7% (43/52) were males. Robotic LITA harvesting was successfully completed in 98.1% (51/52) of patients (one patient had a graft injury), with no perioperative mortality. Postoperative complications occurred in 38.5% (20/52), mostly due to atrial fibrillation (19.2%, 10/52) and acute kidney injury (13.5%, 7/52) with no correlation with operative times at logistic regression. According to thoracic indexes, no correlation was found between chest complexity and postoperative complications. Neither EuroSCORE II, BMI nor thoracic indices significantly impacted operative times. Linear regression demonstrated significant reductions in overall surgical and graft-harvesting times across the experience, suggesting improved efficiency. RA-MIDCAB is feasible and safe, even in patients with challenging thoracic anatomy. This early experience demonstrated promising outcomes and significant learning curve improvements, supporting the potential for broader adoption of this technique even in patients unlikely deemed suitable for minimally invasive cardiac revascularization surgery.

Dynamic Virtual Simulation with Real-Time Haptic Feedback for Robotic Internal Mammary Artery Harvesting

Coronary heart disease, a leading global cause of mortality, has witnessed significant advancement through robotic coronary artery bypass grafting (CABG), with the internal mammary artery (IMA) emerging as the preferred "golden conduit" for its exceptional long-term patency. Despite these advances, robotic-assisted IMA harvesting remains challenging due to the absence of force feedback, complex surgical maneuvers, and proximity to the beating heart. This study introduces a novel virtual simulation platform for robotic IMA harvesting that integrates dynamic anatomical modeling and real-time haptic feedback. By incorporating a dynamic cardiac model into the surgical scene, our system precisely simulates the impact of cardiac pulsation on thoracic cavity operations. The platform features high-fidelity representations of thoracic anatomy and soft tissue deformation, underpinned by a comprehensive biomechanical framework encompassing fascia, adipose tissue, and vascular structures. Our key innovations include a topology-preserving cutting algorithm, a bidirectional tissue coupling mechanism, and dual-channel haptic feedback for electrocautery simulation. Quantitative assessment using our newly proposed Spatial Asymmetry Index (SAI) demonstrated significant behavioral adaptations to cardiac motion, with dynamic scenarios yielding superior SAI values compared to static conditions. These results validate the platform's potential as an anatomically accurate, interactive, and computationally efficient solution for enhancing surgical skill acquisition in complex cardiac procedures.

Developing Proficiency in Robotic Cardiac Surgery

BACKGROUND

The purpose of this review is to provide recommendations for cardiac surgeons interested in adopting a robotic platform into their programs.

METHODS

The recommendations are based on the experience of the authors and cover a diverse array of cardiac surgical procedures that are currently performed with robotic assistance. The focus, as with any innovative surgical approach, is to ensure patient safety, maximize quality and efficacy, and set realistic expectations about what is required to achieve proficiency in robotic cardiac surgery.

RESULTS

Even though there may be steady growth in robotic cardiac procedures, it is possible that these procedures will be concentrated in higher-volume programs that already offer expertise in mitral valve or coronary surgery. Once success and proficiency with robotic cardiac approaches to coronary or valvular heart disease is achieved, as outlined in this review, surgeons may wish to embark on more complex robotic procedures, such as reoperative mitral valve surgery, totally endoscopic coronary artery bypass, or aortic valve replacement.

CONCLUSIONS

Maintaining the same principles and techniques for coronary surgery or intracardiac procedures and maintaining the fundamentals of myocardial protection and cardiopulmonary bypass are essential to ensure excellent technical and clinical outcomes and to optimize patient safety.

A machine learning framework to adjust for learning effects in medical device safety evaluation

OBJECTIVES

Traditional methods for medical device post-market surveillance often fail to accurately account for operator learning effects, leading to biased assessments of device safety. These methods struggle with non-linearity, complex learning curves, and time-varying covariates, such as physician experience. To address these limitations, we sought to develop a machine learning (ML) framework to detect and adjust for operator learning effects.

MATERIALS AND METHODS

A gradient-boosted decision tree ML method was used to analyze synthetic datasets that replicate the complexity of clinical scenarios involving high-risk medical devices. We designed this process to detect learning effects using a risk-adjusted cumulative sum method, quantify the excess adverse event rate attributable to operator inexperience, and adjust for these alongside patient factors in evaluating device safety signals. To maintain integrity, we employed blinding between data generation and analysis teams. Synthetic data used underlying distributions and patient feature correlations based on clinical data from the Department of Veterans Affairs between 2005 and 2012. We generated 2494 synthetic datasets with widely varying characteristics including number of patient features, operators and institutions, and the operator learning form. Each dataset contained a hypothetical study device, Device B, and a reference device, Device A. We evaluated accuracy in identifying learning effects and identifying and estimating the strength of the device safety signal. Our approach also evaluated different clinically relevant thresholds for safety signal detection.

RESULTS

Our framework accurately identified the presence or absence of learning effects in 93.6% of datasets and correctly determined device safety signals in 93.4% of cases. The estimated device odds ratios' 95% confidence intervals were accurately aligned with the specified ratios in 94.7% of datasets. In contrast, a comparative model excluding operator learning effects significantly underperformed in detecting device signals and in accuracy. Notably, our framework achieved 100% specificity for clinically relevant safety signal thresholds, although sensitivity varied with the threshold applied.

DISCUSSION

A machine learning framework, tailored for the complexities of post-market device evaluation, may provide superior performance compared to standard parametric techniques when operator learning is present.

CONCLUSION

Demonstrating the capacity of ML to overcome complex evaluative challenges, our framework addresses the limitations of traditional statistical methods in current post-market surveillance processes. By offering a reliable means to detect and adjust for learning effects, it may significantly improve medical device safety evaluation.

Examining the learning curves in robotic cardiac surgery wet lab simulation training

BACKGROUND

Simulation-based training has gained distinction in cardiothoracic surgery as robotic-assisted cardiac procedures evolve. Despite the increasing use of wet lab simulators, the effectiveness of these training methods and skill acquisition rates remain poorly understood.

OBJECTIVES

This study aimed to compare learning curves and assess the robotic cardiac surgical skill acquisition rate for cardiac and noncardiac surgeons who had no robotic experience in a wet lab simulation setting.

METHODS

In this prospective cohort study, participants practiced 3 robotic tasks in a porcine model: left atriotomy closure, internal thoracic artery harvesting and mitral annular suturing. Participants were novice robotic cardiac and noncardiac surgeons alongside experienced robotic cardiac surgeons who established performance benchmarks. Performance was evaluated using the time-based score and modified global evaluative assessment of robotic skills (mGEARS).

RESULTS

The participants were 15 novice surgeons (7 cardiac; 8 noncardiac) and 4 experienced robotic surgeons. Most novices reached mastery in 52 (±22) min for atrial closure, 32 (±18) for internal thoracic artery harvesting and 34 (±12) for mitral stitches, with no significant differences between the cardiac and noncardiac surgeons. However, for mGEARS, noncardiac novices faced more challenges in internal thoracic artery harvesting. The Thurstone learning curve model indicated no significant difference in the learning rates between the groups.

CONCLUSIONS

Wet lab simulation facilitates the rapid acquisition of robotic cardiac surgical skills to expert levels, irrespective of surgeons' experience in open cardiac surgery. These findings support the use of wet lab simulators for standardized, competency-based training in robotic cardiac surgery.

Association between caseload volume and outcomes in left ventricular assist device implantations - a EUROMACS analysis

AIMS

This EUROMACS study was conducted with the primary aim of investigating the association between a centre's annual caseload and postoperative outcomes among patients undergoing left ventricular assist device (LVAD) implantation.

METHODS AND RESULTS

A total of 4802 patients identified between 2011 and 2020 from 35 participating centres were dichotomized based on the annual caseload of the treating centre at the time of device implant (≤30 vs. >30 LVAD implantations/year). The primary endpoint was 1-year survival. Secondary outcomes included overall survival analysis, device-related adverse events and readmissions. Cumulative follow-up was 10 003 patient-years, with a median follow-up of 1.54 years (interquartile range 0.52-3.15). Patients from higher volume centres more frequently presented in INTERMACS levels 1 and 2, suffered from right heart dysfunction and needed inotropic support. No difference was observed in adjusted 1-year survival. Adjusted overall survival probability was lower in higher volume centres (p = 0.002). In the subgroup analysis of HeartMate 3 devices only, higher volume centres were associated with decreased odds of 1-year survival (adjusted odds ratio 0.43, 95% confidence interval 0.20-0.97, p = 0.041). Similar findings were observed in the cumulative (i.e. learning curve) caseload analyses.

CONCLUSION

In patients undergoing LVAD implantation, centre volume was not associated with 1-year survival, but was related to device-related adverse events. Patient profiles differed with respect to centre size. These findings underscore the necessity for ongoing quality improvement initiatives in all centres, regardless of their annual caseload. Efforts are needed to standardize patient selection and preconditioning to further improve patient outcome.

Nonphysician Evaluators and Recording-Based Tools in Surgical Skill Assessment: A Feasibility Study

OBJECTIVES

To investigate the feasibility of nonmedically trained evaluators and image- and video-based tools in the assessment of surgical skills in a key orthopedic procedure.

DESIGN

Orthopedic surgeons at varying skill levels were evaluated by their ability to repair a cadaveric bi-malleolar ankle fracture. Nonphysician viewers and expert orthopedic surgeons independently scored video recordings and fluoroscopy images of the procedure through Global Rating Scales (GRS) and procedure-specific checklist tools. Statistical analysis was used to determine if the evaluators and assessment tools were able to differentiate skill level.

SETTING

An academic tertiary care hospital.

PARTICIPANTS

The surgical procedure was completed by 3 orthopedic residents, 3 orthopedic trauma fellows, and 4 orthopedic trauma attending surgeons. The procedure was independently evaluated by 2 orthopedic surgeons and 2 nonphysicians.

RESULTS

Operating participants were stratified by ≤ or >10 bimalleolar ankle fracture cases performed alone (inexperienced, n = 5 vs experienced, n = 5). Expert surgeon viewers could effectively stratify skill group through the GRS for video and fluoroscopy analysis (p < 0.05), and the video procedure-specific checklist (p < 0.05), but not the fluoroscopy procedure-specific checklist. Nonphysician viewers generally recognized skill groupings, although with less separation than surgeon viewers. These evaluators performed the best when aided by video and fluoroscopy procedure-specific checklists. Meanwhile, breakdowns of each tool into critical zones for improvement and evaluator-independent metrics such as case experience, self-reported confidence, and surgical time also indicated some skill differentiation.

CONCLUSIONS

The feasibility of using video recordings and fluoroscopic imaging based surgical skills assessment tools in orthopedic trauma was demonstrated. The tools highlighted in this study are applicable to both cadaver laboratory settings and live surgeries. The degree of training that is required by the evaluators and the utility of measuring surgical times of specific tasks should be the subject of future studies.

Systematic review and meta-analysis of two decades of reported outcomes for robotic coronary artery bypass grafting

Background

Despite the well-documented safety and feasibility of robotic coronary artery bypass grafting (CABG), widespread adoption of this approach remains limited by its steep learning curve, high procedural costs and paucity of data on longer-term efficacy. This current meta-analysis aims to provide a systematic overview of the outcomes of robot-assisted CABG, with a focus on long term graft patency and freedom from major adverse cardiac and cerebrovascular events (MACCE).

Methods

A systematic literature search of three electronic databases was conducted for studies reporting outcomes of robotic-assisted CABG, and were grouped based on whether patients underwent robot-assisted minimally invasive direct coronary artery bypass (RA-MIDCAB), totally endoscopic coronary artery bypass (TECAB) or were mixed. Perioperative and mid-to-long term results from included studies were pooled using meta-analysis of proportion or means in a random effects model.

Results

In the quantitative analysis, thirty-nine eligible studies included 6,152 patients who underwent RA-MIDCAB, 1,729 patients who underwent TECAB and 21,642 patients who underwent either form of robot-assisted CABG. A high level of heterogeneity was observed amongst baseline characteristics. Perioperative mortality and complication rates were low. Conversion rate to full sternotomy overall was less than 3.2% [95% confidence interval (CI): 2.1-5.2%, I2=39%]. At a mean follow-up duration of 5.2 years, overall graft patency was 96% for both RA-MIDCAB and TECAB, and freedom from major adverse cardiac events (MACE) or MACCE was 83.2% (95% CI: 72.0-90.4%; I2=90%) for RA-MIDCAB and 91.6% (95% CI: 86.6-94.9%; I2=76%) for TECAB.

Conclusions

Robot-assisted CABG is observed to have acceptable perioperative and mid-to-long term outcomes with promising overall graft patency.

Learning Curve for No-Touch Vein Harvesting Technique in Off-Pump Coronary Artery Bypass Grafting

INTRODUCTION

The present study sought to analyze the learning curve of no-touch vein harvesting technique in off-pump coronary artery bypass grafting (CABG).

METHODS

Logarithmic curve fitting was used to analyze learning curves based on operative time for 160 patients that underwent no-touch CABG. The clinical data of 89 of these patients whose number of grafts was 3 were further retrospectively analyzed based on Cumulative Sum (CUSUM) analysis. Patients were divided into two groups, referring to the surgeon's learning period and maturation period in chronological order. Perioperative outcomes were compared between two groups.

RESULTS

In this study, the learning curve for no-touch vein harvesting technique in off-pump CABG was quantitatively assessed in 51 cases through CUSUM analysis, and the results from logarithmic curve fitting corroborated these findings, indicating a significant milestone in proficiency gain for practitioners. Compared with patients in surgeon's learning period, the median of the operative, Aorta-saphenous vein graft (SVG) anastomosis, and SVG checking time in the maturation period was significantly shorter (230 min vs. 250 min, p = 0.002; 11.5 min vs. 13.0 min, p = 0.025; 9.0 min vs. 11.0 min, p = 0.002). There was less first 48-h chest tube drainage, shorter postoperative hospital stay and rarer delayed incision healing in the leg in the late period compared with that in the early period (312.6 ± 140.7 mL vs. 401.0 ± 233.5 mL, p = 0.029; 11.0 d vs. 12.0 d, p = 0.026; 15.7% vs. 2.6%, p = 0.043).

CONCLUSION

A cardiac surgeon mastered in CABG using the full-incision SVG harvesting method experienced a learning curve to gain early proficiency in no-touch CABG. In the initial learning period, Aorta-SVG anastomosis, bleeding check of SVG, and wound complications need to be paid more attention.

Advanced Fellowships After Training: Super or Not?

Advanced training in cardiothoracic surgery has become more prevalent in the setting of increased complexity of interventions. Minimally invasive techniques, transcatheter and endovascular interventions, and rapid growth in mechanical circulatory support and transplant have led approximately 40% of trainees to pursue additional training. Available data suggest trainees seek additional training for 3 main reasons: gain an additional skillset, improve candidacy for a job, and/or increase proficiency in basic areas. This review provides an analysis of existing literature, categorized by specialty (cardiac, thoracic, and congenital) to determine areas where additional training is of benefit.

Less Invasive and Hybrid Surgical/Interventional Coronary Disease Management: The Future Is Now

Coronary artery bypass grafting (CABG) has evolved to become the criterion standard in elective revascularisation for coronary artery disease (CAD), particularly in patients with complex or multivessel CAD, left main involvement, diabetes mellitus, or left ventricular dysfunction. Despite the superiority of CABG in patients with the most advanced forms of CAD, a standard CABG operation, through a median sternotomy and with the use of cardiopulmonary bypass, carries well recognised challenges. In this article, we describe newer approaches, such as off-pump CABG, minimally invasive bypass grafting, robotic CABG, and hybrid coronary revascularisation, which we consider as necessary ways to minimise invasion, reduce recovery time, provide the benefits of arterial grafting to more patients, and offer alternatives to mitigate the adverse effects of conventional sternotomy and cardiopulmonary bypass.

Robotic applications for intracardiac and endovascular procedures

The large incisions and long recovery periods that accompany traditional cardiac surgery procedures along with the constant patient demand for minimally invasive procedures have motivated cardiac surgeons to implement the robotic technologies in their armamentarium. The robotic systems have been utilized successfully in various cardiac procedures including atrial septal defect repair, left atrial myxoma resection, MAZE procedure and left ventricular lead placement, yet coronary artery bypass and mitral valve repair still comprise the vast majority of them. This review analyzes the development of the robot-assisted cardiac surgery in recent years, its outcomes, advantages, disadvantages, its patient selection criteria as well as its economic feasibility. Robotic endovascular surgery, albeit its limited applications, is presently considered an attractive alternative to conventional endovascular approaches. The increased flexibility and precision along with the wider range of accessible anatomy provided by the endovascular robotic systems, have increased the pool of patients that can be offered minimally invasive treatment options and have helped to overcome many limitations of the traditional endovascular procedures. With this review we aimed to summarize the applications of the commercially available endovascular robotic devices, as well as the limitations and the future perspectives in the field of endovascular robotic surgery.

Coronary Artery Surgery: Past, Present, and Future

Coronary artery bypass grafting (CABG) is the most commonly performed and studied major cardiac operation worldwide. An understanding of the evolution of CABG, including the early days of cardiac surgery, the first bypass operation, continuous improvements in techniques, and streamlining of the operation, is important to inform current trends and future innovations. This article will examine how CABG evolved (from techniques to conduits), describe current trends in the field, and explore what lies on the horizon for the future of CABG.

The Society of Thoracic Surgeons Adult Cardiac Surgery Database: 2022 Update on Outcomes and Research

The Society of Thoracic Surgeons Adult Cardiac Surgery Database is the most mature and comprehensive cardiac surgery database. It is one of the most respected clinical data registries in health care, providing accurate risk-adjusted benchmarks, a foundation for quality measurement and improvement activities, and the ability to perform novel research. This report encompasses data from the years 2020 and 2021 and is the seventh in a series of reports that provide updated volumes, outcomes, database-related developments, and research summaries using the Adult Cardiac Surgery Database.