Cor-Knot device is an automated suture fastening system which was introduced to minimize the operating time during cardiac surgery. It is currently being used for intracardiac suturing applications such as implanting valves or rings during aortic and mitral valve surgery primarily for shortening the procedure time. It also has higher holding pressures and more consistent holding pressures than manual knots. We describe here the use of Cor-Knot device in extracardiac suturing to secure aortic root vent as well as aortic cannulation during minimally invasive cardiac surgery. A 60-year-old male with mitral valve endocarditis underwent minimally invasive mitral valve replacement via right mini thoracotomy. Direct ascending aortic cannulation was performed through a separate port. Cor-Knots were successfully used to secure the purse-string sutures after decannulation at the end of the case.
Epicardial exclusion of LAA has gained increasing popularity since its introduction in 2009. While the clip has demonstrated a success rate ranging from 93.9-100% in excluding the LAA, one significant complication is incomplete exclusion due to residual stump (> 1 cm) as a result of the clip being deployed too distally. We describe here the first reported case of implanting a second clip underneath the first clip to obliterate the residual stump for a 71-year-old male with AF evaluated for intervention for stroke risk reduction.
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.
Title: Cardiac surgery and healthcare quality: Is the right question being asked?Authors : Abdullah Nasif, MD1/ Saqib Masroor, MD1 1Division of Cardiothoracic Surgery, Department of Surgery, University of Toledo Medical Center Toledo, OH USAManuscript: Minimally Invasive Mitral Valve Surgery After Previous Sternotomy: A Propensity-Matched Analysis.Disclosure : NoneWord Count : 1381Even though by 2003, Casselman (and many others) had concluded that totally endoscopic mitral valve repair can be performed safely with excellent results and a high degree of patient satisfaction1, less than a quarter of all isolated mitral valve procedures were performed using minimally invasive approach (MIS) by 20162. Conventional sternotomy (ST) remains the approach of choice in the majority of cardiac surgery centers. Since 2011, partial sternotomy has fallen out of favor and right mini thoracotomy (RMT) approach has been the major MIS approach (with or without robotics) for both primary as well as re-operative mitral valve surgery. At experienced centers, the indications for MIS surgery have been expanded to include complex pathologies, reoperative surgery, endocarditis, as well as a hybrid open approach for severely calcified mitral annuli using an open deployment of transcatheter aortic valve3-5.One reason for the slow adoption of MIS has been the lack of randomized prospective trials comparing the conventional sternotomy approach with MIS. Most literature supporting the use of MIS has consisted of retrospective review of series of individual surgeons or centers, which have shown a shorter length of stay, reduced need for transfusions and a quicker recovery2,3. Since these reports came from centers with extensive experience and the fact that initial cohorts of patients undergoing MIS were relatively lower risk patients, these retrospective observational studies were not as convincing in their conclusions, because the two groups of patients were not similar. Only a few propensity-matched analyses comparing MIS vs sternotomy have so far been reported in patients undergoing primary surgery4-6.For re-operative mitral valve surgery, there has been one propensity-matched comparison of 42 pairs of patients undergoing right mini-thoracotomy MIS vs sternotomy from China7. MIS patients had lower transfusions, shorter length of stay and lower costs, while having similar mortality. However, the study had a mean length of stay of 22 days vs 16 days and mortality of 11% vs 7 % for sternotomy and MIS patients, respectively and thus the results cannot be reliably generalized.In this issue of the Journal , Hamandi et al8, reviewed 305 isolated MV reoperations that were performed in a single institution between 2007-2018. Patients who underwent MIS MV reoperation totaled 199, while sternotomy operations were 106. The primary endpoints were operative mortality and 1-year survival with operative complications and length of stay being secondary endpoints. Median age of patients was 69 years with an equal gender distribution. The team performed propensity-matched analysis to compare the two groups.There were 88 well-balanced matched pairs. There was no statistically significant difference in mortality among the matched groups at 30 days (3.4% vs 8.0%, p=0.19) or at 1-year (15.9% vs. 16.5%, p=0.9). Comparing long-term survival rates, no statistically significant difference was found up to 5 years postoperatively. Also, the incidence of post-operative complications such as atrial fibrillation, valve dysfunction or renal failure didn’t show any statistically significant difference. However, intraoperative blood utilization was significantly lower among the MIS cohort (p<0.01). Patient satisfaction was not evaluated as is not possible in a retrospective analysis. Neither was readmission rates and other similar measures which would be important in a value-based care system.The 30-day mortality difference (3.4% vs 8%), while not statistically significant, tended to be lower in MIS patients. 4 patients in the MIS group converted to sternotomy due to adhesions. It is not clear from the manuscript, if the mortality in the MIS group was in some way related to the conversions or not. But based on our experience over the years and from the analysis of this manuscript, we recommend an early conversion to sternotomy if one is dealing with difficult adhesions, rather than risking a long tedious operation and possibly emergently converting to sternotomy. It is also important to note that 75% of patients were discharged home, however readmission rate is unknown. With the advent of value-based purchasing, readmission rates should also be looked at. Overall, the authors should be congratulated on their excellent management of this subset of patients and for taking the time share their experience with us.Propensity score matching is commonly used in evaluation research to estimate average treatment effects.9 The main benefit in using this statistical method is to remove confounding bias from observational cohorts. It attempts to reduce the effects of confounders by matching already treated subjects with control subjects who exhibit a similar propensity for treatment based on preexisting covariates that influence treatment selection. However, it is limited in that it requires the removal of data and works primarily on binary treatments. In this study, by including standardized mean difference (SMD), the authors were able to balance the covariates in this propensity-matched analysis.Other than being a single-center retrospective study, this study suffered from other short-comings of a propensity match study, such as the loss of study power due to the decreased sample size after performing propensity matching. Also, “the surgeon effect” was noted. Since the MIS MV reoperative surgeries were performed by the same surgeons who performed the sternotomy cases, the results may not be generalizable.The question being addressed by this manuscript (and by most other similar comparisons of one therapy vs another) is, “Is MIS better than sternotomy?”Unfortunately, that question cannot be satisfactorily addressed with this or similar studies. Healthcare quality has evolved since its inception in 1999 with the Institute of Medicine report, titled “To Err is human”. In the subsequent report “Crossing the Quality Chasm”11, a high-quality care is defined as beingsafe, effective, patient-centered, timely, efficient and equitable. Our healthcare delivery system is changing, and so should our research methodologies. Our analyses should go deeper than scratching the surface with mortality and morbidity data. Most studies, including this one by Hamandi et al, do not even address “effectiveness” adequately in the context of healthcare quality. Having similar mortality and morbidity means that both approaches are equally ‘safe ’. We have little information about other measures of safety, such as readmissions, central line associated blood borne infections. We have not evaluated whether the two approaches were patient centered (Did the patient participate in choosing the approach?), efficient (Cost of care) or equitable.As cardiac surgeons dealing with life and death from up close, we are not used to viewing healthcare from the rather distant 6-pronged quality viewpoint mentioned above. But this is important for a very important reason which I explain below.Individual surgeons and patients may not have the power to bring about a meaningful change in the way we do business everyday. But just like state pension funds pressured oil companies into facing climate change10, big stakeholders like insurance companies and other payers may be able to convince the cardiac surgeons to face the future. For that to happen, quality metrics such as readmission rates, cost of care and patient satisfaction must be looked at and reported, because that is how these stakeholders assess quality. According to some studies7 MIS approach is better in terms of cost and patient satisfaction. Such comprehensive analyses of quality will go a long way in answering a slightly different question than the one posed earlier; “Does MIS offer better quality than sternotomy?”If we want to influence healthcare delivery and have a passion for quality, then our research methodology must reflect the high standards, that we have set for our clinical work. We should also develop new measures of quality besides morbidity and mortality. We have to look at those metrics that have traditionally been ignored by surgeons, but are important for the payers and the hospitals that rely on these payers for their success. As far a minimally invasive vs sternotomy approach is concerned, that question is not going to last for long. Not because one side would have won or the other lost, but because for those that have not yet boarded the train of minimally invasive mitral valve surgery, that train may have already left the station, moving at full speed ahead towards the “percutaneous station”. It is not a matter of if , but when , sternotomy would not be the standard of care for mitral valve surgery. Today’s vascular surgeons save open repair of abdominal aortic aneurysm for a very small subset of patients. There is no reason to believe that tomorrow’s mitral valve surgeons will consider open sternotomy any differently for mitral valve surgery.