Title: Learning the Learning Curve of Robotic Coronary Artery BypassAuthors : Saqib Masroor, MD, MBA1, Abdullah Nasif, MD1 1Division of Cardiothoracic Surgery, Department of Surgery, University of Toledo Medical Center Toledo, OH USAManuscript: The Learning Curve of Robotic Coronary Arterial Bypass Surgery: A Report from The STS DatabaseDisclosure : NoneWord Count : 1229Learning the learning curve of robotically assisted coronary artery bypass grafting is important for the advancement of this technique and the improvement in patient outcomes. There have been many reports of single surgeon learning curves.1, 2 But one can argue that they depict one surgeon’s journey, depicting his or her dedication to the field and making generalization to other surgeons difficult, if not impossible.In this issue of the Journal of Cardiac Surgery, Patrick et al, report on their investigation of the Society of Thoracic Surgeons (STS) database for Robotically Assisted Coronary Artery Bypass (RA-CABG) procedures and the beginner surgeon’s learning curve.3Between 2014 and 2018, a total of 1195 RA-CABGs were performed by 114 surgeons, with 74 surgeons performing <5 procedures and only 9 surgeons performing >25 procedures. The median number of cases performed was 2. The patient population was younger and relatively lower risk. The cases included single-vessel as well as multi-vessel Minimally Invasive Direct Coronary Artery Bypass (MIDCAB) in addition to Totally Endoscopic Coronary Artery Bypass (TECAB) and there is no subgroup analysis reported for the different procedures. The authors conclude that the learning curve for procedural success is overcome by the 10th case, even though the curve for reoperation is still steep by the 25th case. Operative mortality however was similar in the two groups. The authors conclude that surgeon experience is an independent predictor of RA-CABG procedural success and that the learning curve consistently flattens after the surgeon’s 10th case. We agree with the first but not the second conclusion. Here is why!In 2013, Prof Mohr’s group in Leipzig reported on the learning curve of minimally invasive mitral valve surgery at their institution over a 17-year period involving 3895 operations performed by 17 surgeons performing their first minimally invasive procedure, using the sequential probability cumulative sum (CUSUM) statistical technique.4 Learning curves were then determined for total operation times, aortic cross-clamp times, and primary outcomes. The mean number of operations per surgeon was 189. The authors reported a learning curve of between 75-125 procedures, with evidence that surgeons needed to perform more than 1 cases per week to maintain good results. Importantly however, patient mortality was not compromised because of the learning curve.To assess the learning curve involved in performing a task, it is important that both the task and the tools needed for the task remain constant. The above publication fulfills both of these criteria. 82 percent of cases were mitral valve repair and 18 percent were mitral valve replacement. The surgical technique and technology used was nearly identical and robotic mitral valve procedures were excluded. The institution had the same leadership over the period, allowing for a very stable work environment as well as a consistent approach including case selection, operative technique etc. As much as possible, every variable was the same, except the variable under investigation-‘the beginner surgeon’. The same group had reported the learning curve for MIDCAB to be between 50-100 cases for 8 surgeons at their institution.5Now let us analyze the report from Patrick et al.3 In this report, the task is not the same and neither are the tools. Single vessel RA-MIDCAB is a less challenging procedure than multi-vessel RA-MIDCAB, with its associated variety of conduit procedures (such as bilateral Internal Mammary Artery (IMA) grafting, Radial Artery T-grafting from Left Internal Mammary Artery (LIMA) to the lateral wall, or aortocoronary Saphenous Vein bypass procedures). TECAB is a totally different beast altogether. Grouping all of them in one learning curve is not a valid assumption. As far as the tools/technique is concerned, some patients had beating heart surgery while others had arrested heart procedures, exposing the Left Anterior Descending Artery (LAD) in MIDCAB is a different task than exposing the lateral wall targets or the stabilizing the LAD endoscopically. Each one of those steps/techniques have their own learning curves.Another shortcoming of this study is the relatively small experience of most of the surgeons in the study. 74 out of the 114 surgeons in the study had < 5-case experience. Moreover, it is not clear what the experience of the surgeons was before embarking on this technique. In the Leipzig study, surgeons with less than 5 cases were excluded from analysis and the 17 surgeons had an experience of at least 40 mitral valve procedures via sternotomy before using the minimally invasive approach.1Finally, the definition of procedural success can be debated. It was defined as an inverse composite of the three primary outcomes - conversion, re-operation, and major morbidity/mortality. While this “procedural success” composite showed a flattening of the learning curve at 10 cases, the reoperation rate was still improving even after 25 cases. A chain is only as strong as the weakest link. If the reoperation rate is still improving after 25 cases, procedural success cannot be declared to have been mastered at 10 cases. Further analysis of the groups of surgeons with < 10 or > 10 cases reveals the procedural success to be 72.9% and 85.3% respectively. 15% failure of procedural success would not be consistent with overcoming the learning curve. We assume that surgeons must strive to continue improving the procedural success until it reaches well into the 90’s percent rate, which would be required for a successful RA-CABG program.The major advantage of a large clinical database such as the Adult Cardiac Surgery Database (ACSD) is the minimization of bias due to its large number of observations. However, for rare procedures such as RA-CABG, that advantage is lost. In fact, with such a small number of observations over such a diverse set of procedures and institutions, ACSD data is not granular enough to explore an individual surgeon’s learning curve because there is no control for numerous other variables at the departmental and institutional level that are not tracked by ACSD. A high-volume center in a steady-state clinical work environment controls for most variables that influence clinical outcomes. The only variable that changes, is the beginner surgeon, and the data thus obtained is more likely to represent the true “learning curve” of the procedure.It is important to have realistic expectations from new technology. Many beginners would embark on this journey, hoping to master the learning curve in 10 cases. And when that expectation is not fulfilled in real life, they might give up altogether on this very useful approach. The number and frequency of operations are important, not just for the surgeons, but even more so, for the rest of the operating room team including anesthesiologists and patient-side assistants. The whole team can be feel discouraged if they continue to have a learning curve beyond 10 or even 20 cases.In conclusion, querying the Adult Cardiac Surgery Database of STS may not be the best way of learning the learning curve of a rare procedure(s). There is a concern that setting an unrealistically optimistic expectation of 10 operative cases to master the learning curve of RA-CABG may be detrimental to the progress of this approach. A high-volume centers’ experience with multiple beginner surgeons may be a better representative of the learning curve of RA-CABG and that study has not yet been done. But based on the learning curves of other similar procedures and our own experience, it is our opinion that the learning curve of RA-CABG would be somewhere between 50 and 100 cases for MIDCAB and another 50-100 for TECAB.
We have read with great interest the article by Papakonstantinou et al. providing a single-center analysis of the contemporary approach to tricuspid aortic valve (TAV) insufficiency with the use of HAART 300 annuloplasty ring .We believe that the presented concept of a robust circumferential aortic annuloplasty with separate sinus replacement, avoiding coronary re-implantations when allowed, can be successfully applied to many cases, including BAV.
Microinvasive, catheter-based mitral valve repair of severe mitral regurgitation utilizes less invasive approaches with less procedural morbidity and mortality. The procedural steps and clinical benefits of the transcatheter transapical mitral valve annuloplasty (AMEND mitral repair implant) and transcatheter transapical chordal repair systems (Neochord DS 1000 device and Harpoon Mitral Valve Repair System) are reviewed in this manuscript.
Background. We have observed reopening of the occluded “no-touch” saphenous vein (NT SV) composite grafts on follow-up angiograms in patients who underwent coronary artery bypass graftings (CABG). Methods. Between 2008 and 2018, 1283 patients received NT SV conduits without or with surrounding pedicle tissue as composite grafts based on the in situ left internal thoracic artery (ITA) for CABG and underwent early postoperative angiographies. Among the 1283 patients, 53 patients showed 55 occluded SV conduit anastomoses, and 46 patients who had 48 occluded SV anastomoses were re-evaluated by 1-year postoperative angiographies. Results. Early postoperative angiographies in 1283 patients demonstrated overall occlusion rates of 1.2% (56/4518); occlusion rates of the ITA and SV were 0.08% (1/1259) and 1.7% (55/3260), respectively. One-year angiograms demonstrated that 14 occluded SV anastomoses (29.2% [14/48 occluded SV]) of 14 patients became patent. Reopening of occluded SV conduits occurred more frequently in NT SV with pedicle tissue than in NT SV without pedicle tissue (45.0% [9/20] versus 17.9% [5/28]; P=0.057). When we examined the preoperative and 1-year postoperative angiograms, reopening of the occluded SV conduits was not related with progression (P=0.258) or preoperative reversibility score (P=0.115) of native target coronary artery disease. Conclusions. More than a quarter of the occluded SV composite grafts on early postoperative angiograms were patent in the 1-year angiograms. The reopening rates were higher in patients who had received NT SV conduits with pedicle tissue than those who had received NT SV conduits without pedicle tissue.
A recent administration of potent P2Y12 receptor inhibitor such as prasugrel in patients undergoing cardiac surgery remains a dilemma and little is known about its impact on platelet function recovery. Guidelines recommend discontinuation of prasugrel 7 days before surgery to reduce the risk of surgery-related bleeding. Patients at risk may benefit from preoperative platelet function testing to guide individualized preoperative waiting time. We present a rare case of complete function recovery in a patient treated with prasugrel revealed by preoperative platelet function monitoring before urgent coronary artery bypass surgery (CABG). A complete platelet function recovery was revealed by platelet function testing after discontinuation of prasugrel for four days and patient underwent urgent CABG without increased risk of postoperative bleeding. Our case with a review of literature emphasized that the decision to proceed with urgent CABG in a patient recently treated with prasugrel should be based on a personalized risk assessment and might be supported by preoperative platelet function monitoring to shorten the waiting time.
There is increasing attention being given toward social and ethical implications of xenotransplantation that may begin relatively soon. IN a recent commentary by Loebe and Parker, the authors address many of the social and ethical issues in regard to xenotransplantation, but do so only superficially. This letter to the editor responds to many of the points they raise.
Machine learning and artificial intelligence (AI) in medicine has arrived in medicine and the healthcare community is experiencing significant growth in its adoption across numerous patient care settings. There are countless applications for machine learning and AI in medicine ranging from patient outcome prediction, to clinical decision support, to predicting future patient therapeutic setpoints. This commentary discusses a recent application leveraging machine learning to predict one year patient survival following orthotopic heart transplantation. This modeling approach has significant implications in terms of improving clinical decision making, patient counseling, and ultimately organ allocation and has been shown to significantly outperform preexisting algorithms. This commentary also discusses how adoption and advancement of this modeling approach in the future can provide increased personalization of patient care. The continued expansion of information systems and growth of electronic patient data sources in healthcare will continue to pave the way for increased use and adoption of data science in medicine. Personalized medicine has been a long-standing goal of the healthcare community and with machine learning and AI now being continually incorporated into clinical settings and practice, this technology is well on the pathway to make a considerable impact to greatly improve patient care in the near future.
Pulmonary artery pseudoaneurysms are a rare but potentially lethal diagnosis. They can be further categorized by etiology or location and are typically successfully treated with endovascular therapies. However, they occasionally require operative intervention. Here, we present a case of a patient who presented with a central pulmonary artery pseudoaneurysm on CT scan with unclear etiology that was initially treated with conservative management. However, this was noted to have rapid enlargement on interval imaging necessitating urgent surgical intervention. The patient underwent a median sternotomy, anterior pulmonary artery arteriotomy for exposure, exclusion of the posterior artery pseudoaneurysm with a bovine pericardial patch, and closure of the anterior arteriotomy with a bovine pericardial patch. The patient did well and was discharged on postoperative day eleven with repeat imaging showing resolution.
Null hypothesis significance testing (NHST) and p-values are widespread in the cardiac surgical literature but are frequently misunderstood and misused. The purpose of the review is to discuss major disadvantages of p-values and suggest alternatives. We describe diagnostic tests, the prosecutor’s fallacy in the courtroom, and NHST, which involve inter-related conditional probabilities, to help clarify the meaning of p-values, and discuss the enormous sampling variability, or unreliability, of p-values. Finally, we use a cardiac surgical database and simulations to explore further issues involving p-values. In clinical studies, p-values provide a poor summary of the observed treatment effect, whereas the three- number summary provided by effect estimates and confidence intervals is more informative and minimises over-interpretation of a “significant” result. P-values are an unreliable measure of strength of evidence; if used at all they give only, at best, a very rough guide to decision making. Researchers should adopt Open Science practices to improve the trustworthiness of research and, where possible, use estimation (three-number summaries) or other better techniques.
Patients with severely calcified aorta undergoing conventional cardiac surgery are at increased risk for postoperative neurologic deficits. Implementation of cerebroprotective devices may substantially reduce or even eliminate the risk of adverse neurologic event, thus enabling surgical therapy, especially when interventional treatment cannot be considered an alternative option.
Background: Bicuspid aortic valve is the most common congenital heart defect and predisposes patients to developing aortic stenosis more frequently and at a younger age than the general population. However, the influence of bicuspid aortic valve on the rate of progression of aortic stenosis remains unclear. Methods: In 236 patients (177 tricuspid aortic valve, 59 bicuspid aortic valve) matched by initial severity of mild or moderate aortic stenosis, we retrospectively analyzed baseline echocardiogram at diagnosis with latest available follow-up echocardiogram. Baseline comorbidities, annualized progression rate of hemodynamic parameters, and hazard of aortic valve replacement were compared between valve phenotypes. Results: Median echocardiographic follow-up was 2.6 (IQR 1.6-4.2) years. Patients with tricuspid aortic stenosis were significantly older with more frequent comorbid hypertension and congestive heart failure. Median annualized progression rate of mean gradient was 2.3 (IQR 0.6-5.0) mmHg/year vs. 1.5 (IQR 0.5-4.1) mmHg/year (p=0.5), and that of peak velocity was 0.14 (IQR 0-0.31) m/s/year vs. 0.10 (IQR 0.04-0.26) m/s/year (p=0.7) for tricuspid vs. bicuspid aortic valve, respectively. On multivariate analyses, bicuspid aortic valve was not significantly associated with more rapid progression of aortic stenosis. In a stepwise Cox proportional hazards model adjusted for baseline mean gradient, bicuspid aortic valve was associated with increased hazard of aortic valve replacement (HR: 1.7, 95% CI [1.0, 3.0], p=0.049). Conclusion: Bicuspid aortic valve may not significantly predispose patients to more rapid progression of mild or moderate aortic stenosis. Guidelines for echocardiographic surveillance of aortic stenosis need not be influenced by valve phenotype.
Background: Takotsubo cardiomyopathy (TC) is defined as a temporary and reversible systolic abnormality of the left ventricle’s apical area resembling myocardial infarction (MI) in the nonexistence of coronary artery disease (CAD).Only a few cases have been reported after cardiac operations or after pericardiocentesis. Aims: To emphasize the need to be aware of the possibility of the occurrence of this potentially fatal complication after cardiac surgery. Materials and methods: A-66-year old man underwent pericardiectomy.Postoperative he endured TC and progressed exacerbation of hemodynamic instability.finally, he had to be supported by intra-aortic balloon pump（IABP),extracorporeal membrane oxygenation（ECMO). Results: Patient’s left ventricle function recovered fully in two weeks. Discussion: we discussed the pathogenesis and treatment of postoperative TC. Conclusion:TC has to be carefully considered in differential diagnosis in case of acute left ventricle dysfunction following cardiac surgery. Keywords: pericardiectomy; takotsubo cardiomyopathy.
Background & Aim Cardiogenic shock (CS) withholds a significantly high mortality rate between 40-60% despite advances in diagnosis and medical/surgical intervention. To-date, machine learning(ML) is being implemented to integrate numerous data to optimize early diagnostic predictions and suggest clinical courses. This systematic review summarizes the area under the curve (AUC) receiver operating characteristics (ROC) accuracy for the early prediction of CS. Methods A systematic review was conducted within databases of PubMed, ScienceDirect, Clinical Key/MEDLINE, Embase, GoogleScholar, and Cochrane. Cohort studies that assessed accuracy of early detection of CS using ML software were included. Data extraction was focused on AUC-ROC values directed towards early detection of CS. Results A total of 943 studies were included for systematic review. From the reviewed studies, 2.2% (N=21) evaluated patient outcomes, of which 14.3% (N=3) were assessed. The collective patient cohort (N=698) consisted of 314(45.0%) females, with an average age and body mass index (BMI) of 64.1years and 28.1kg/m2, respectively. Collectively, 159 (22.8%) mortalities were reported following early CS detection. Altogether, the AUC-ROC value was 0.82 (alfa=0.05), deeming it of superb sensitivity and specificity. Conclusions From the present comprehensively gathered data, this study accounts the use of ML software for the early detection of CS in a clinical setting as a valid tool to predict patients at risk of CS. The complexity of ML and its parallel lack of clinical evidence implies that further prospective randomized control trials are needed to draw definitive conclusions prior to standardizing use of these technologies.
The present perspective is a synthesis of 80 published investigations in the setting of a retroaortic left brachiocephalic vein, described in 250 patients. Clinical presentation, radiographic findings, ultrasonographic findings, saline contrast echocardiography, computed-tomographic angiocardiography, magnetic resonance imaging, and angiocardiography provided the diagnostic information used to define the disease entity prior to considering the surgical approach to the associated cardiac anomalies. We have also addressed several issues concerning the influence of isomerism, the establishment of diagnosis, and its importance in various surgical and interventional procedures. Although the retroaortic left brachiocephalic vein is asymptomatic, its recognition during clinical investigation should raise the possibility of an association with other malformations, especially right aortic arch, ventricular septal defect, and anomalies of the outflow tracts. We submit that an increased appreciation of this venous anomaly may facilitate surgical planning, endovascular procedures, placement of central venous lines, and transvenous pacemakers.
Background: This study evaluated the utilization and outcomes of postcardiotomy mechanical circulatory support (MCS). Methods: This was a retrospective, single institution analysis of adult cardiac surgery cases that required de novo MCS following surgery from 2011-2018. Patients that were bridged with MCS to surgery were excluded. The primary outcomes were early operative mortality and longitudinal survival. Secondary outcomes included postoperative complications, and five-year all-cause readmission. Results: 533 patients required de novo postcardiotomy MCS, with the most commonly performed procedure being isolated coronary artery bypass grafting (29.8%). Median cardiopulmonary bypass and cross clamp times were 185 (IQR 123-260) minutes and 122 (IQR 81-179) minutes, respectively. A total of 442 (82.9%) of patients were supported with intra-aortic balloon pump counterpulsation, 23 (4.3%) with an Impella device, and 115 (21.6%) with extracorporeal membrane oxygenation. Three (0.6%) patients had an unplanned ventricular assist device placed. Operative mortality was 29.8%. Longitudinal survival was 56.1% and 43.0% at 1- and 5-years, respectively. Survival was lowest in those supported with ECMO and highest with those supported with an Impella (P<0.001). Freedom from readmission was 61.4% at 5-years. Postoperative ECMO was an independent predictor of mortality (HR 5.1, 95% CI 2.0-12.9, P<0.001), but none of the MCS types predicted long-term hospital readmission after risk adjustment. Conclusions: Postcardiotomy MCS is associated with high operative mortality. Even patients that survive to discharge have compromised longitudinal survival, with nearly only half surviving to 1-year. Close follow-up and early referral to advanced heart failure specialists may be prudent in improving these outcomes.
Key Points : • Interventional therapies directed at fenestration closure in the Fontan patient must rely on good hemodynamic data • The Large Optimus-CVSTM stent is an additional armamentarium for fenestration closure however, longer term follow up is needed • Multi institutional studies defining the long-term benefits of fenestration closure and outlining fenestration management guidelines may help improve the long-term morbidity and mortality in this group of patients.
The case report by Sicim et al. is the placement of extra-anatomical bypasses in bilateral common carotid arteries. The similar previous reports of the extra-anatomical bypass usually indicate unilateral bypass. Whether or not the Willis' circle is incomplete is difficult to judge during emergency surgery, and the authors' judgment seems to have been correct in the sense that it could maintain cerebral perfusion reliably and quickly. The direct perfusion and extraanatomical bypass of carotid artery is a reasonable strategy in patients with cerebral malperfusion.