How to improve performance of robotic totally endoscopic coronary artery bypass grafting

Minimal-Access Coronary Revascularization: Past, Present, and Future

Minimal-access cardiac surgery appears to be the future. It is increasingly desired by cardiologists and demanded by patients who perceive superiority. Minimal-access coronary artery revascularisation has been increasingly adopted throughout the world. Here, we review the history of minimal-access coronary revascularization and see that it is almost as old as the history of cardiac surgery. Modern minimal-access coronary revascularization takes a variety of forms-namely minimal-access direct coronary artery bypass grafting (MIDCAB), hybrid coronary revascularisation (HCR), and totally endoscopic coronary artery bypass grafting (TECAB). It is noteworthy that there is significant variation in the nomenclature and approaches for minimal-access coronary surgery, and this truly presents a challenge for comparing the different methods. However, these approaches are increasing in frequency, and proponents demonstrate clear advantages for their patients. The challenge that remains, as for all areas of surgery, is demonstrating the superiority of these techniques over tried and tested open techniques, which is very difficult. There is a paucity of randomised controlled trials to help answer this question, and the future of minimal-access coronary revascularisation, to some extent, is dependent on such trials. Thankfully, some are underway, and the results are eagerly anticipated.

Fibrin and Thrombin Sealants in Vascular and Cardiac Surgery: A Systematic Review and Meta-analysis

OBJECTIVE

In vascular and cardiac surgery, the ability to maintain haemostasis and seal haemorrhagic tissues is key. Fibrin and thrombin based sealants were introduced as a means to prevent or halt bleeding during surgery. Whether fibrin and thrombin sealants affect surgical outcomes is poorly established. A systematic review and meta-analysis was performed to examine the impact of fibrin or thrombin sealants on patient outcomes in vascular and cardiac surgery.

DATA SOURCES

Cochrane CENTRAL, Embase, and MEDLINE, as well as trial registries, conference abstracts, and reference lists of included articles were searched from inception to December 2019.

REVIEW METHODS

Studies comparing the use of fibrin or thrombin sealant with either an active (other haemostatic methods) or standard surgical haemostatic control in vascular and cardiac surgery were searched for. The Cochrane risk of bias tool and the ROBINS-I tool (Risk Of Bias In Non-randomised Studies - of Interventions) were used to assess the risk of bias of the included randomised and non-randomised studies; quality of evidence was assessed by the Grading of Recommendations Assessment, Development and Evaluation (GRADE) framework. Two reviewers screened studies, assessed risk of bias, and extracted data independently and in duplicate. Data from included trials were pooled using a random effects model.

RESULTS

Twenty-one studies (n = 7 622 patients) were included: 13 randomised controlled trials (RCTs), five retrospective, and three prospective cohort studies. Meta-analysis of the RCTs showed a statistically significant decrease in the volume of blood lost (mean difference 120.7 mL, in favour of sealant use [95% confidence interval {CI} -150.6 - -90.7; p < .001], moderate quality). Time to haemostasis was also shown to be reduced in patients receiving sealant (mean difference -2.5 minutes [95% CI -4.0 - -1.1; p < .001], low quality). Post-operative blood transfusions, re-operation due to bleeding, and 30 day mortality were not significantly different for either RCTs or observational data.

CONCLUSION

The use of fibrin and thrombin sealants confers a statistically significant but clinically small reduction in blood loss and time to haemostasis; it does not reduce blood transfusion. These Results may support selective rather than routine use of fibrin and thrombin sealants in vascular and cardiac surgery.

Article Commentary: Hemostats, Sealants, and Adhesives: A Practical Guide for the Surgeon

Hemostats, sealants, and adhesives are useful adjuncts to modern surgical procedures. To maximize their benefit, a surgeon needs to understand the safety, efficacy, usability, and cost of these agents. To be truly added to a surgeon's own toolbox, the operator must also have knowledge of when and how to best use these materials. This commentary is designed to succinctly facilitate this understanding and knowledge. A nomenclature and classification system based on group, category, and class has been created to help with this process and is provided here. By using this system, materials consisting of similar design and for common indications can be compared. For example, in this system, the three functional groups are hemostats, sealants, and adhesives. The hemostats may be divided into four categories: mechanical, active, flowable, and fibrin sealant. These hemostat categories are further subdivided into generic classes based on the composition of the approved materials. Similarly, categories and classes are provided for sealants and adhesives. In this commentary, the salient points with respect to the characteristics of these agents are presented. A discussion of when these agents can be used in specific indications and how they may be applied to achieve the best results is also provided.

Factors causing prolonged mechanical ventilation and peri-operative morbidity after robot-assisted coronary artery bypass graft surgery

Robot-assisted coronary artery bypass graft [robot-assisted (coronary artery bypass grafting (CABG)] surgery is the latest treatment for coronary artery disease. However, the surgery extensively affects cardiac and pulmonary function, and the risk factors associated with peri-operative morbidity, including prolong mechanical ventilation (PMV), have not been fully examined. In this retrospective cohort study, a total of 382 patients who underwent robot-assisted internal mammary artery harvesting with mini-thoracotomy direct-vision bypass grafting surgery (MIDCABG) from 2005 to 2012 at our tertiary care hospital were included. The definition of PMV was failure to wean from mechanical ventilation more than 48 h after the surgery. Risk factors for PMV, and peri-operative morbidity and mortality were analyzed with a multivariate logistic regression model. Forty-three patients (11.3%) developed PMV after the surgery, and the peri-operative morbidity and mortality rates were 38 and 2.6%, respectively. The risk factors for PMV were age, left ventricular ejection fraction (LVEF), the duration of one-lung ventilation for MIDCABG (beating time), and peak airway pressure at the end of the surgery. Furthermore, age and anesthesia time were found to be independent risk factors for peri-operative morbidity, whereas age, LVEF, and anesthesia time were the risk factors for peri-operative mortality. These findings may help physicians to properly choose patients for this procedure, and provide more attention to patients with higher risk after surgery to achieve better clinical outcomes.

Novel Dry-Lab Training Method for Totally Endoscopic Coronary Anastomosis: A Pilot Study

OBJECTIVE

We describe our original dry-lab training system for nonrobotic and beating heart endoscopic coronary artery anastomosis.

METHODS

All the materials used for this training were commercially available. We selected a boxed machine, which can produce pulsatile movements of artificial vessels, and on its roof, we installed a two-dimensional home video camera and a monitor. A multiple-holed plate was placed in front of the machine, and through these holes, a trainee inserted endoscopic surgical instruments and anastomosed the artificial vessels by running fashion while watching the monitor. This training program has four stages. During the first stage, a trainee has to demonstrate mastery in conducting a conventional off-pump coronary artery anastomosis without assistance. The second stage is the "nonbeating" version, and the third stage is the "beating" version with the model mentioned previously. After a trainee gets accustomed to the third stage, the original artificial vessel is replaced with an extremely fragile one, and this is the fourth stage. Our trainee conducted one hundred fourth-stage anastomoses and each procedure was recorded with the video camera. We analyzed several factors from the videos and evaluated the efficacy of the training method. We compared the outcomes of the first 50 consecutive anastomoses with the following 50 ones and described the learning curves.

RESULTS

The comparison showed a significant decrease in anastomotic time and vessel injury. We considered the quality of anastomosis acceptable after 47 anastomoses, and anastomotic time fell below 15 minutes at the 81st training at the fourth stage.

CONCLUSIONS

Our dry-lab system might be an effective training method for endoscopic coronary anastomosis.

Can the Learning Curve of Totally Endoscopic Robotic Mitral Valve Repair be Short-Circuited?

Objective

A concern with the initiation of totally endoscopic robotic mitral valve repair (TERMR) programs has been the risk for the learning curve. To minimize this risk, we initiated a TERMR program with a defined team and structured learning approach before clinical implementation.

Methods

A dedicated team (two surgeons, one cardiac anesthesiologist, one perfusionist, and two nurses) was trained with clinical scenarios, simulations, wet laboratories, and “expert” observation for 3 months. This team then performed a series of TERMRs of varying complexity.

Results

Thirty-two isolated TERMRs were performed during the first programmatic year. All operations included mitral valve repair, left atrial appendage exclusion, and annuloplasty device implantation. Additional procedures included leaflet resection, neochordae insertion, atrial ablation, and papillary muscle shortening. Longer clamp times were associated with number of neochordae ( P < 0.01), papillary muscle procedures ( P < 0.01), and leaflet resection ( P = 0.06). Sequential case number had no impact on cross-clamp time ( P = 0.3). Analysis of nonclamp time demonstrated a 71.3% learning percentage ( P < 0.01; ie, 28.7% reduction in nonclamp time with each doubling of case number). There were no hospital deaths or incidences of stroke, myocardial infarction, unplanned reoperation, respiratory failure, or renal failure. Median length of stay was 4 days. All patients were discharged home.

Conclusions

Totally endoscopic robotic mitral valve repair can be safely performed after a pretraining regimen with emphasis on experts’ current practice and team training. After a pretraining regimen, cross-clamp times were not subject to learning curve phenomena but were dependent on procedural complexity. Nonclamp times were associated with a short learning curve.

Multivessel beating heart robotic myocardial revascularization increases morbidity and mortality

OBJECTIVE

The vast majority of reports describing beating heart robotic myocardial revascularization (total endoscopic coronary artery bypass) contain very small numbers of patients undergoing single-vessel bypass. We present a large series of patients undergoing multivessel total endoscopic coronary artery bypass.

METHODS

We performed a retrospective clinical review of 106 patients undergoing total endoscopic coronary artery bypass (72% multivessel) at 1 institution by 1 experienced cardiac surgeon/physician assistant team. These results were compared with the expected clinical outcomes from conventional coronary artery bypass grafting calculated using the Society of Thoracic Surgeons risk calculator.

RESULTS

Of the 106 patients, 1% underwent quadruple total endoscopic coronary artery bypass, 8% triple, 63% double, and 28% single. The emergent conversion rate for hemodynamic instability was 6.6%. The postoperative renal failure rate (doubling of baseline serum creatinine or dialysis required) was 7.5%. Overall, 23 patients (21.7%) exhibited at least 1 major morbidity/mortality (4 deaths). The number of vessels bypassed (single/double/triple/quadruple) correlated positively with the surgical/operating room time, the lung separation time, vasoactive medication use, blood use, a postoperative ventilation time longer than 24 hours, intensive care unit length of stay, and hospital length of stay. An increased surgical time was significantly associated with major morbidity (P = .011) and mortality (P = .043). A comparison with the Society for Thoracic Surgeons expected outcomes revealed a similar hospital length of stay but an increased incidence of prolonged ventilation (P = .003), renal failure (P < .001), morbidity (P = .045), and mortality (P = .049).

CONCLUSIONS

Our results suggest that addressing multivessel coronary artery disease using total endoscopic coronary artery bypass offers no obvious clinical benefits and might increase the morbidity and mortality.

The golden age of minimally invasive cardiothoracic surgery: current and future perspectives

Over the past decade, minimally invasive cardiothoracic surgery (MICS) has grown in popularity. This growth has been driven, in part, by a desire to translate many of the observed benefits of minimal access surgery, such as decreased pain and reduced surgical trauma, to the cardiac surgical arena. Initial enthusiasm for MICS was tempered by concerns over reduced surgical exposure in highly complex operations and the potential for prolonged operative times and patient safety. With innovations in perfusion techniques, refinement of transthoracic echocardiography and the development of specialized surgical instruments and robotic technology, cardiac surgery was provided with the necessary tools to progress to less invasive approaches. However, much of the early literature on MICS focused on technical reports or small case series. The safety and feasibility of MICS have been demonstrated, yet questions remain regarding the relative efficacy of MICS over traditional sternotomy approaches. Recently, there has been a growth in the body of published literature on MICS long-term outcomes, with most reports suggesting that major cardiac operations that have traditionally been performed through a median sternotomy can be performed through a variety of minimally invasive approaches with equivalent safety and durability. In this article, we examine the technological advancements that have made MICS possible and provide an update on the major areas of cardiac surgery where MICS has demonstrated the most growth, with consideration of current and future directions.

Establishing the case for minimally invasive, robotic-assisted CABG in the treatment of multivessel coronary artery disease

The purpose of this review is to outline the most common objections about robotic coronary artery bypass graft (CABG), often expressed by cardiac surgeons, cardiologists, and administrators who have little direct knowledge of the procedure. The summarized objections include the high intraoperative costs of robotic versus traditional CABG, a prolonged and difficult learning curve for members of the surgical team, and concerns about compromising graft patency with this technique. Arguments for continued procedure development in robotically assisted CABG are provided.