Robotic-assisted coronary artery bypass surgery: an 18-year single-centre experience.

BACKGROUND: Minimally invasive robot-assisted direct coronary artery bypass (RADCAB) has emerged as a feasible minimally invasive surgical technique for revascularization that might offer several potential advantages over conventional approaches. We present our 18-year experience in RADCAB. METHODS: Between February 1998 and February 2016, 605 patients underwent RADCAB. Patients underwent post-procedural selective graft patency assessment using cardiac catheterization. RESULTS: The mortality rate was 0.3%. The rate of conversion to sternotomy for any cause was reduced from 16.0% of the first 200 cases to 6.9% of the last 405 patients. The patency rate of the LITA-to-LAD anastomosis was 97.4%. Surgical re-exploration for bleeding occurred in 1.8% of patients, and the transfusion rate was 9.2%. Average ICU stay was 1.2 ± 1.4 days, and average hospital stay was 4.8 ± 2.9 days. CONCLUSIONS: Robot-assisted coronary artery bypass grafting is safe, feasible and it seems to represent an effective alternative to traditional coronary artery bypass grafting in selected patients.

The role of visual and direct force feedback in robotics-assisted mitral valve annuloplasty.

BACKGROUND: The objective of this work was to determine the effect of both direct force feedback and visual force feedback on the amount of force applied to mitral valve tissue during ex vivo robotics-assisted mitral valve annuloplasty. METHODS: A force feedback-enabled master-slave surgical system was developed to provide both visual and direct force feedback during robotics-assisted cardiac surgery. This system measured the amount of force applied by novice and expert surgeons to cardiac tissue during ex vivo mitral valve annuloplasty repair. RESULTS: The addition of visual (2.16 ± 1.67), direct (1.62 ± 0.86), or both visual and direct force feedback (2.15 ± 1.08) resulted in lower mean maximum force applied to mitral valve tissue while suturing compared with no force feedback (3.34 ± 1.93 N; P < 0.05). CONCLUSIONS: To achieve better control of interaction forces on cardiac tissue during robotics-assisted mitral valve annuloplasty suturing, force feedback may be required.

Evaluating the effect of three-dimensional visualization on force application and performance time during robotics-assisted mitral valve repair.

OBJECTIVE: The purpose of this study was to determine the effect of three-dimensional (3D) binocular, stereoscopic, and two-dimensional (2D) monocular visualization on robotics-assisted mitral valve annuloplasty versus conventional techniques in an ex vivo animal model. In addition, we sought to determine whether these effects were consistent between novices and experts in robotics-assisted cardiac surgery. METHODS: A cardiac surgery test-bed was constructed to measure forces applied during mitral valve annuloplasty. Sutures were passed through the porcine mitral valve annulus by the participants with different levels of experience in robotics-assisted surgery and tied in place using both robotics-assisted and conventional surgery techniques. RESULTS: The mean time for both the experts and the novices using 3D visualization was significantly less than that required using 2D vision (P < 0.001). However, there was no significant difference in the maximum force applied by the novices to the mitral valve during suturing (P = 0.7) and suture tying (P = 0.6) using either 2D or 3D visualization. The mean time required and forces applied by both the experts and the novices were significantly less using the conventional surgical technique than when using the robotic system with either 2D or 3D vision (P < 0.001). CONCLUSIONS: Despite high-quality binocular images, both the experts and the novices applied significantly more force to the cardiac tissue during 3D robotics-assisted mitral valve annuloplasty than during conventional open mitral valve annuloplasty. This finding suggests that 3D visualization does not fully compensate for the absence of haptic feedback in robotics-assisted cardiac surgery.

The early inflammatory response in a mini-cardiopulmonary bypass system: a prospective randomized study.

OBJECTIVE: The aim of this study was to compare the early systemic inflammatory response of the Resting Heart System (RHS; Medtronic, Minneapolis, MN USA), a miniaturized cardiopulmonary bypass (CPB) system, with two groups using a standard extracorporeal circulation system during on-pump coronary artery bypass grafting (CABG) surgery. METHODS: A total of 60 consecutive patients requiring CABG were prospectively randomized to undergo on-pump CABG using conventional CPB without cardiotomy suction (group A), conventional CPB with cardiotomy suction (group B), or the RHS (group C). Blood samples were collected at five time points: immediately before CPB, 30 minutes into CPB, immediately at the end of CPB, 30 minutes post-CPB, and 1 hour post-CPB. Inflammation was analyzed by changes in (a) levels of plasma proteins, including inflammatory cytokines (interleukin-6 [IL-6], IL-10, and tumor necrosis factor-α), chemokines (IL-8, monokine induced by interferon-γ, monocyte chemotactic protein-1, regulated on activation normal T cell expressed and secreted, and interferon-inducible protein-10), and acute phase proteins (C-reactive protein and complement protein 3); (b) biochemical variables (cardiac troponin I, hematocrit, and immunoglobulin G); and (c) cell numbers (leukocytes, neutrophils, and thrombocytes). RESULTS: The RHS showed more delayed secretion of the cytokines tumor necrosis factor-α and IL-10, chemokines monokine induced by interferon-γ (P < 0.001); IL-8, and interferon-inducible protein-10; and complement protein 3 than conventional CPB systems did. Median thrombocyte numbers were higher in the RHS group. Levels of cardiac troponin I, monocyte chemotactic protein-1, and IL-6 were lower in both the RHS and conventional CPB without suction than with suction. Levels of C-reactive protein and regulated on activation normal T cell expressed and secreted, plus leukocyte and neutrophil numbers, were similar in all groups. CONCLUSIONS: The Medtronic RHS may induce less systemic inflammation than conventional CPB systems, particularly when cardiotomy suction was used, but it did not result in improved clinical benefit.

Bivalirudin as an anticoagulant for simultaneous integrated coronary artery revascularization - a novel approach to an inherent concern.

BACKGROUND: Simultaneous integrated coronary artery revascularization combines coronary artery bypass surgery and percutaneous coronary intervention into a single procedure. This approach provides immediate, complete and optimal myocardial revascularization in a less invasive manner. Because simultaneous integrated coronary revascularization necessitates two distinct anticoagulation protocols for the surgical and percutaneous aspects of the procedure, combining these anticoagulation protocols carries a bleeding risk. Using a single anticoagulant to facilitate the necessities of both aspects of the integrated approach may alleviate this risk. CASE PRESENTATION: A 45-year-old man with an occluded left anterior descending artery and a moderately stenotic circumflex artery underwent simultaneous integrated coronary revascularization. Bivalirudin was used to achieve anticoagulation for the duration of the procedure. The patient was asymptomatic with excellent patency of both the bypass graft and the stented circumflex artery via angiography at 10 months. CONCLUSION: Bivalirudin can be used to effectively achieve a unified anticoagulation protocol for simultaneous integrated revascularization.

Simultaneous integrated coronary artery revascularization with long-term angiographic follow-up.

OBJECTIVE: Traditionally integrated coronary artery revascularization has been described as a 2-stage procedure. We evaluated the safety and feasibility of 1-stage, simultaneous, hybrid, robotically assisted coronary artery bypass grafting surgery and percutaneous coronary intervention. METHODS: Fifty-eight patients underwent simultaneous, integrated coronary artery revascularization in an operating theater equipped with angiographic equipment. Forty-five patients were men. The mean age was 59 years. All internal thoracic arteries were harvested with robotic assistance. All anastomoses were manually constructed through a small anterior non-rib-spreading incision without cardiopulmonary bypass on the beating heart. Immediately after and within the same operative suite, both angiographic confirmation of graft patency and percutaneous coronary intervention were performed. In 52 patients therapeutic anticoagulation was achieved with the direct thrombin inhibitor bivalirudin. RESULTS: There were no deaths or wound infections. There was 1 perioperative myocardial infarction. One patient had a stroke, and 3 patients required re-exploration for bleeding. The median lengths of intensive care and hospital stay were 1 and 4 days, respectively. All patients were alive and symptom free at follow-up (mean, 20.2 months; range, 1.1-40.8 months). Long-term angiographic follow-up in 54 patients showed 49 (91%) patent grafts (mean, 9.0 months; range, 4.3-40.8 months). There were 7 in-stent restenoses and 2 occluded stents. CONCLUSION: For multivessel coronary artery disease, simultaneous integrated coronary artery revascularization with bivalirudin is safe and feasible. This approach enables complete multivessel revascularization with decreased surgical trauma and postoperative morbidity. Further studies are necessary to better determine patient selection and long-term outcomes.

Prospective angiographic comparison of direct, endoscopic, and telesurgical approaches to harvesting the internal thoracic artery.

BACKGROUND: The purpose of this study was to compare the quality of left internal thoracic arteries harvested by the conventional open approach versus minimally invasive videoscopic and robotic-assisted telesurgical techniques. METHODS: One hundred and fifty consecutive patients with single vessel coronary artery disease were prospectively studied. The left internal thoracic artery was harvested using three different approaches, with 50 patients consecutively assigned to each group. The off-pump coronary artery bypass (OPCAB) group underwent median sternotomy with direct visualization. The automated endoscopic system for optimal positioning (AESOP) group employed the AESOP 3000 system (Computer Motion Inc, Goleta, CA) for robotic-assisted visualization with endoscopic manual left internal thoracic artery harvesting. The Zeus group used the Zeus robotic telesurgical system (Computer Motion Inc) and internal thoracic artery harvesting was performed remotely from a surgical console. Postanastomotic left internal thoracic artery flows and day one postoperative angiography were used to assess internal thoracic artery quality and patency. RESULTS: Average left internal thoracic artery harvest times were 23 +/- 2.5, 63.3 +/- 20.3, and 66.1 +/- 17.9 minutes in the OPCAB, AESOP, and Zeus groups, respectively (p < 0.001, OPCAB vs AESOP and Zeus). Intraoperative graft flows averaged 28.1 +/- 11.9, 33.7 +/- 19.3, and 36.9 +/- 24.6 mL/minute, respectively in the OPCAB, AESOP, and Zeus groups (p = 0.317, OPCAB vs AESOP and Zeus). There was no significant angiographic difference in the patency rate of the harvested left internal thoracic arteries in the three groups (p = 0.685, overall). CONCLUSIONS: The left internal thoracic artery can be harvested safely and effectively using minimally invasive videoscopic and robotic-assisted telesurgical techniques. Although the less invasive approaches require specialized equipment and training as well as increased operative time, they offer the potential for less traumatic myocardial revascularization through smaller incisions and reduced postoperative morbidity.

Computer-enhanced telemanipulation in mitral valve repair: preliminary experience in Canada with the da Vinci robotic system.

BACKGROUND: Investigation into the surgical application of robot technology continues to expand. We report on the first case series of robotic-assisted mitral valve (RAMV) repair in Canada with use of the da Vinci telemanipulation system (Intuitive Surgical, Sunnyvale, Calif.). METHODS: Between February 2004 and August 2004, 10 patients with normal left ventricular function and severe mitral valve regurgitation underwent RAMV repair with use of the da Vinci system. Peripheral cardiopulmonary bypass, transthoracic aortic cross-clamping and antegrade cardioplegia were used in all cases. A minithoracotomy in the fourth intercostal space and 2 ports in the third and fifth intercostal spaces allowed surgical access. All mitral valve valvuloplasties and band annuloplasties were done endoscopically with robotic assistance. RESULTS: Nine of 10 patients had successful valve repair, and 1 had conversion to mitral valve replacement due to persistent regurgitation. There were no deaths, strokes or need for sternotomy. One patient required re-exploration for bleeding. CONCLUSION: Minimally invasive RAMV repair is feasible and safe with promising early postoperative results when performed by experienced surgical personnel accomplished in both mitral valve procedures and robotic techniques.

Robotic-assisted left atrial ligation for stroke reduction in chronic atrial fibrillation: a case report.

Patients with atrial fibrillation are at significant risk for sustaining a thromboembolic stroke. More than 90% of thromboemboli form in the left atrial appendage. Ligation of the left atrial appendage to reduce the risk of stroke is often performed in connection with other cardiac surgical procedures. As a stand-alone procedure, however, left atrial ligation has generally been deemed too invasive and has gained little support as an alternative therapeutic option. We report a case of port-access robotic-assisted left atrial ligation as a stand-alone procedure in a patient with chronic atrial fibrillation in whom anticoagulation was a contraindication. To our knowledge, this is the first reported case of stand-alone robotic-assisted left atrial ligation in the literature.

Concurrent robotic hybrid revascularization using an enhanced operative suite.

Hybrid myocardial revascularization combines coronary surgery with percutaneous intervention as an alternative therapy for ischemic heart disease. The order and sequence of the hybrid approach is not yet clearly defined. We report on the benefits of an enhanced surgical suite equipped with a carbon fiber operating table and digital C-arm for robotic-assisted hybrid revascularization in a single operative sequence. To our knowledge, this is the first reported case of concurrent robotic-assisted hybrid revascularization utilizing an enhanced operative suite.

Effects of latency on telesurgery: an experimental study.

The paper is concerned with determining the feasibility of performing telesurgery over long communication links. It describes an experimental testbed for telesurgery that is currently available in our laboratory. The tesbed is capable of supporting both wired and satellite connections as well as simulated network environments. The feasibility of performing telesurgery over a satellite link with approximately 600 ms delay is shown through a number of dry and wet lab experiments. Quantative results of these experiments are also discussed.

Robot-assisted cardiac surgery.

The use of robotics is evolving in cardiac surgery. Robots allow minimally invasive techniques to be applied to ischemic heart and valve disease. Notably, this frees the patient from sternotomy, allowing a quick recovery while preserving the most critical aspects of the surgical procedure. The increasing use of stents for revascularization is significant. For best results to the patient, the graft of the left internal mammary artery (LIMA) to the left anterior descending artery (LAD) is a mainstay of symptom-free survival. Stenting and robotic LIMA-to-LAD grafting in a one-staged or two-staged approach may be an attractive combined specialty treatment. This would offer best practices to the patient, along with the best technologies available. In this chapter, the most common techniques in cardiac robotic surgery are outlined. Procedural steps are described, and their expanding indications for use discussed. Additionally, a focus on combining technologies for new treatments is considered.

Robotic Surgery, the First 100 Cases: Where Do We Go from Here?

Abstract Background: Since the robot-assisted cardiac surgery program at this center was initiated in September 1998 the results have been regularly critically evaluated. We report a retrospective review of the first 100 robotic procedures and their evolution. Methods: Between September 1998 and May 2001, 146 patients underwent robot-assisted procedures. All procedures were performed using the Aesop robotically controlled camera or the Zeus robotic system. A harmonic scalpel was used for all internal thoracic artery (ITA) dissections whether the dissections were performed manually or with the Zeus robotic system. Results: There were 123 closed-heart and 23 open-heart procedures, which included 8 atrial-septal defect repairs, 11 mitral valve repairs, 4 mitral valve replacements, 57 Aesop ITA takedowns, 68 Zeus ITA takedowns, and 13 totally endoscopic coronary artery bypass grafts. Graft patency in Aesop and Zeus ITA takedown groups was 96%. All the patients were New York Heart Association class I after their procedures. Conclusion: With the development of surgical robots, it has been possible to perform endoscopic cardiac surgery for selected cases. Future directions will be demonstrated, including telementoring, telesurgery, and Zeus-assisted initiatives in cardiac surgery and other surgical disciplines.

Analysis of the learning curve in telerobotic, beating heart coronary artery bypass grafting: a 90 patient experience.

BACKGROUND: Recent articles have commented on the "learning curve" in robotic-assisted coronary artery bypass grafting. We systematically studied this phenomenon using standard statistical and cumulative sum (CUSUM) failure methods. METHODS: Ninety patients underwent internal thoracic artery (ITA) takedown and an attempt at ITA to coronary bypass on the beating heart using the Zeus telerobotic system from September 1999 to December 2001. The rates of mortality and 11 predefined major complications were compared in five quintiles of 18 consecutive patients each and a CUSUM curve was generated for the entire cohort. RESULTS: All patients but one underwent successful endoscopic ITA takedown. Thirteen patients had a totally endoscopic anastomosis, whereas in 61 a small mini-thoracotomy or mini-sternotomy was used. Sixteen patients (17.8%) were converted electively to a sternotomy: 11 patients underwent off-pump and 5 patients on-pump surgery. There were no deaths; 13 patients (14.4%) incurred one or more of the 11 major complication(s), including 5, 1, 2, 3, and 2 in each of the five quintiles (p = 0.39). Standard statistical analyses identified a significant decrease in operating room time (p < 0.0001), as well as a decrease in the incidence of an occluded graft or wrong vessel grafted from quintiles 1 to 5 (p = 0.03). On CUSUM analysis, the failure curve was steep for the first 18 to 20 patients, before moderating its slope for the remainder of the experience. CONCLUSIONS: Robotic ITA to coronary bypass on the beating heart has a moderately steep learning curve, which is mitigated by further experience. CUSUM analysis complimented standard statistical methods in detecting a cluster of suboptimal results during the early experience with this procedure.

Early experience with robotically assisted internal thoracic artery harvest.

We sought to determine the efficacy of using robotic assistance to facilitate endoscopic harvesting of internal thoracic arteries (ITAs). A total of 104 patients had ITAs harvested endoscopically with use of both the AESOP 3000 system (Computer Motion, Goleta, CA, U.S.A.) and Zeus robotic telesurgical system (Computer Motion). All ITAs were harvested with a harmonic scalpel (Ethicon Endosurgery, Cincinnati, OH, U.S.A.). With the left lung collapsed, ITAs were harvested with CO2 insufflation through three 5-mm ports in the left chest. All patients tolerated insufflation without hemodynamic compromise. Average ITA harvest time was 61.3 +/- 20.9 minutes. Intraoperative graft flows averaged 36.3 +/- 22.4 mL/min. There were three distal ITA injuries; all other vessels were patent after harvesting and demonstrated no angiographic evidence of injury. This article demonstrates a technique by which ITA can be safely harvested totally endoscopically with use of computer-enhanced robotic systems and a harmonic scalpel, allowing complete pedicle dissection through 5-mm ports with minimal ITA manipulation.

Current status and future directions in computer-enhanced video- and robotic-assisted coronary bypass surgery.

Since 1997, both the Cleveland Clinic and London Health Sciences Centre groups have embraced robotic assistance and more recently demonstrated the efficacy of this technology in totally closed-chest, beating heart myocardial revascularization. This endeavor involved an orderly progression and the learning of new surgical skill sets. We review the evolution of robot-enhanced coronary surgery and forecast the future of endoscopic and computer-enhanced, robotic-enabling technology for coronary revascularization. This report describes a computer-assisted totally closed-chest coronary bypass operation, and preliminary results are discussed. The internal thoracic artery (ITA) was harvested through three 5-mm access ports and prepared and controlled endoscopically. A prototype sternal elevator was used to increase intrathoracic working space. A 10-mm endoscopic stabilizer was placed through the second intercostal space, and the left anterior descending coronary artery was controlled with silastic snares. Telerobotic anastomoses were completed end-to-side using custom-made, double-armed 8-0 polytetrafluroethylene sutures. To date, 84 patients have undergone successful myocardial revascularization with robotic assistance with a 0% surgical mortality rate. ITA harvest, anastomotic, and operating times for the entire group have been longer than for conventional surgery at 61.3 +/- 17.9 minutes, 28.5 +/- 28.2 minutes, and 368 +/- 129 minutes, respectively. Bleeding, ventilatory times, arrhythmias, hospital lengths of stay, and return to normal activity have been reduced. Recently, we have developed a new robotic revascularization strategy called Atraumatic Coronary Artery Bypass that is a promising mid-term step on the pathway to totally endoscopic, beating-heart coronary artery bypass. We conclude that computer-enhanced robotic techniques are safe, and further clinical studies are required to define the full potential of this evolving technology.

Effect of off-pump coronary artery bypass grafting on risk-adjusted and cumulative sum failure outcomes after coronary artery surgery.

BACKGROUND AND AIM: We have shown that cumulative sum (CUSUM) failure analysis may be more sensitive than standard statistical methods in detecting a cluster of adverse patient outcomes after cardiac surgical procedures. We therefore applied CUSUM, as well as standard statistical techniques, to analyze a surgeon's experience with off-pump coronary artery bypass grafting (OPCAB) and on-pump procedures to determine whether the two techniques have similar or different outcomes. METHODS: In 320 patients undergoing nonemergent, first time coronary artery bypass grafting, preoperative patient characteristics, rates of mortality and major complications, and ICU and hospital lengths of stay were compared between the on-pump and OPCAB cohorts using Fisher's exact tests and Wilcoxon two sample tests. Predicted mortality and length of stay were determined using previously validated models of the Cardiac Care Network of Ontario. Observed versus expected ratios of both variables were calculated for the two types of procedures. Furthermore, CUSUM curves were constructed for the on-pump and OPCAB cohorts. A multivariable analysis of the predictors of hospital length of stay was also performed to determine whether the type of coronary artery bypass procedure had an independent impact on this variable. RESULTS: The predicted mortality risk and predicted hospital length of stay were almost identical in the 208 on-pump patients (2.2 +/- 3.9%; 8.2 +/- 2.5 days) and the 112 OPCAB patients (2.0 +/- 2.2%; 7.8 +/- 2.1 days). The incidence of hospital mortality and postoperative stroke were 2.9% and 2.4% in on-pump patients versus zero in OPCAB patients (p = 0.09 and 0.17, respectively). Mechanical ventilation for greater than 48 hours was significantly less common in OPCAB (1.8%) than in on-pump patients (7.7%, p = 0.04). The rate of 10 major complications was 14.9% in on-pump versus 8.0% in OPCAB patients (p = 0.08). OPCAB patients experienced a hospital length of stay that was a median of 1.0 day shorter than on-pump patients (p = 0.01). The observed versus expected ratio for length of stay was 0.78 in OPCAB patients versus 0.95 in on-pump patients. On CUSUM analysis, the failure curve in OPCAB patients was negative and was flatter than that of on-pump patients throughout the duration of the study. Furthermore, OPCAB was an independent predictor of a reduced hospital length of stay on multivariable analysis. CONCLUSIONS: OPCAB was associated with better outcomes than on-pump coronary artery bypass despite a similar predicted risk. This robust finding was documented on sensitive CUSUM analysis, using standard statistical techniques and on a multivariable analysis of the independent predictors of hospital length of stay.