Robot-Assisted Cardiac Surgery

Recognition of the significant advantages of minimizing surgical trauma has resulted in the development of minimally invasive surgical procedures. Endoscopic surgery offers patients the benefits of minimally invasive surgery, and surgical robots have enhanced the ability and precision of surgeons. Consequently, technological advances have facilitated totally endoscopic robotic cardiac surgery, which has allowed surgeons to operate endoscopically rather than through a median sternotomy during cardiac surgery. Thus, repairs for structural heart conditions, including mitral valve plasty, atrial septal defect closure, multivessel minimally invasive direct coronary artery bypass grafting (MIDCAB), and totally endoscopic coronary artery bypass graft surgery (CABG), can be totally endoscopic. Robot-assisted cardiac surgery as minimally invasive cardiac surgery is reviewed.     

Markers of myocardial ischemia after minimally invasive and conventional coronary operation

Background. The purpose of this study was to evaluate the course of serum markers of myocardial tissue damage after two different types of minimally invasive coronary surgical procedures (MICS) as compared with conventional coronary artery bypass grafting (CABG).

Methods. We enrolled 87 patients with one- or two- vessel disease scheduled for one of the three procedures: minimally invasive direct coronary artery bypass grafting (MIDCABG) by lateral thoracotomy (n = 29), the OCTOPUS method by median sternotomy (n = 27), and CABG (n = 31). Creatine kinase activity (CK), creatine kinase MB activity (CK-MB act), creatine kinase MB mass concentration (CK-MB mass), myoglobin concentration (MG), and cardiac troponin I concentration (cTnI) were measured perioperatively until the second postoperative day.

Results. Creatine kinase-MB, CK-MB mass, and cTnI were significantly higher after CABG and were nearly maintained within the normal range in MICS. Creatine kinase and MG were significantly lower in the OCTOPUS group than in the MIDCABG or CABG groups.

Conclusions. Minimally invasive coronary surgical procedures cause less myocardial injury than CABG as indicated by specific serum markers. However, higher CK and MG reflect more substantial skeletal muscle trauma during MIDCABG operation compared with Octopus procedures.     

Port-Access cardiac surgery using endovascular cardiopulmonary bypass: theory, practice, and results

BACKGROUND: Reduction of surgical trauma is the aim of minimally invasive cardiac surgery. This can be achieved by reducing the size of the incision or by eliminating or changing the cardiopulmonary bypass system. However, certain cardiac surgical procedures, such as valvular surgery and complex multivessel coronary artery surgery, are not feasible without the use of cardiopulmonary bypass. Therefore endovascular cardiopulmonary bypass may allow reduction of surgical trauma for these patients. METHODS: Since its first application in April 1995, more than 1100 procedures have been performed worldwide using the EndoCPB endovascular cardiopulmonary bypass system. The authors' experience consists of 60 Port-Access coronary artery bypass grafting procedures, 34 Port-Access mitral valve procedures (18 replacements, 16 repairs), 5 atrial septal defect closures, and 3 atrial myxoma removals. RESULTS: The patient survival rate was 99%, the incidence of perioperative stroke was 1%, and the incidence of aortic dissection was 1%. In the Port-Access mitral valve and atrial septal defect patients, the survival rate was 100% with no peri- or postoperative complications. Peri- and postoperative transesophageal echocardiography revealed no perivalvular leak or remaining mitral insufficiency after valve repair. CONCLUSIONS: The EndoCPB endovascular cardiopulmonary bypass system allows the application of true Port-Access minimally invasive cardiac surgery in procedures that require the use of cardiopulmonary bypass and cardioplegic arrest. Sternotomy and its potential complications can be avoided, and the surgical procedures can be performed safely on an empty, arrested heart with adequate myocardial protection.     

Robotic cardiac surgery: overview

Most endoscopic procedures are excisional, not reconstructive or microsurgical, mostly because conventional endoscopic instrumentation lacks dexterity due to long, nonarticulated instruments, a fixed pivot point and counterintuitive movement of the instrument tip, and lack of depth perception. Endoscopic approaches to cardiac surgery have not been successful; however, the development of robotic surgical systems has overcome many limitations of endoscopy. Computer-assisted surgery has created a computerized digital interface between the surgeon's hands and surgical instrument tips and enhances surgical ability, thereby enabling endoscopic microsurgery. Recently, robotic systems have allowed cardiac surgeons to perform minimally invasive endoscopic coronary artery bypass grafting (CABG) and valve procedures. This article summarizes the use of robotics in cardiac surgery and discusses its potential in our specialty.     

Computer-enhanced "robotic" cardiac surgery: experience in 148 patients

OBJECTIVE: A computer-enhanced instrumentation system was used in 148 patients to minimize access in cardiac surgical procedures. METHODS: The da Vinci telemanipulation system (Intuitive Surgical, Mountain View, Calif) provides a high-resolution 3-dimensional videoscopic image and allows remote, tremor-free, and scaled control of endoscopic surgical instruments with 6 degrees of freedom. By April 2000, the system had been used in 131 patients for coronary artery bypass grafting and 17 patients for mitral valve repair. In the coronary bypass group, the system was used in one of three ways: (1) to take down the internal thoracic artery followed by a minimally invasive direct coronary bypass procedure (n = 81); (2) to perform the anastomosis between the internal thoracic artery and the left anterior descending coronary artery in standard-sternotomy coronary bypass (n = 15); or (3) for total endoscopic coronary artery bypass grafting to anastomose the left internal thoracic artery to the left anterior descending on the arrested heart (n = 27) or the beating heart (n = 8). In 17 patients with nonischemic mitral valve insufficiency the mitral valve was repaired. Closed-chest cardiopulmonary bypass with cardioplegic arrest (Port-Access technique; Heartport, Inc, Redwood City, Calif) was used for arrested-heart total endoscopic coronary bypass and mitral valve repair. RESULTS: The da Vinci system allows for precise tissue handling and enables the endoscopic performance of cardiac surgical tasks that require a high degree of dexterity (coronary anastomosis, mitral valve repair). No technical mishaps have occurred. The internal thoracic artery was successfully taken down in 79 of 81 patients in the group undergoing minimally invasive coronary bypass and, after a steep learning curve, is currently performed in less than 40 minutes. The postoperative patency rate is 96.3%. Total endoscopic coronary bypass was completed in 22 of 27 cases with 95.4% patency as demonstrated by angiography at 3 months' follow-up. Closed-chest endoscopic beating-heart bypass grafting was successfully performed in 2 out of 8 patients with the use of a new endoscopic stabilizer. In the group having mitral valve repair, primary endoscopic computer-enhanced repair was successfully completed in 14 of 17 patients; three others had to be changed to a standard endoscopic technique, including 1 who required valve replacement. At 3 months' follow-up, 1 additional patient underwent early reoperation for recurrent mitral insufficiency. Overall early and late mortality in this cohort of 148 patients was 2.0% and was not related to the use of the system. CONCLUSION: In conclusion, computer-enhanced endoscopic cardiac surgery can be performed safely in selected patients. Internal thoracic artery takedown is now routinely performed with good results. Total endoscopic coronary bypass is feasible on the arrested heart but does not offer a major benefit over the minimally invasive direct approach because cardiopulmonary bypass is still required. The early clinical experience with closed-chest beating-heart bypass grafting outlines the limitations of this approach despite some procedural success.     

Closed chest coronary artery bypass on the beating heart

Minimally invasive surgical procedures have become a part of routine cardiac surgery. The surgical techniques have been developed for the treatment of coronary artery disease in order to minimize surgical trauma. With the introduction of a 3-D-based totally endoscopically functioning system into minimally invasive cardiac (MIC) surgery, further reduction of skin incisions became possible and enhanced MIC techniques could be improved. Due to the 6 degrees freedom of motion allowed by wrist-enhanced instruments and a newly developed endoscopic stabilizer, totally endoscopic coronary artery bypass procedures on a beating heart became feasible. We present here our initial series of totally endoscopic "off-pump" coronary artery bypass grafting in patients suffering from coronary artery single vessel disease. In all patients, the procedure was successfully performed via four 1 cm chest incisions as closed-chest procedures.     

Coronary Surgery: off-pump and port access

Attempts to minimize the invasiveness of cardiac surgery have focused on decreasing access trauma and eliminating cardiopulmonary bypass. The initial procedures, minimally invasive direct coronary artery bypass (MIDCAB, limited access beating heart) and port access (limited access arrested heart), have become niche procedures. Off-pump coronary artery bypass (OPCAB, median sternotomy beating heart) presently accounts for approximately 15% of all coronary bypass operations performed in the United States. Morbidity and cost appear to be decreased with these procedures. Feasibility trials of endoscopic coronary bypass surgery using robotic devices are underway in many centers. It is anticipated that over the next 5 years the alternative approaches to conventional coronary artery bypass surgery will continue to grow as methods of coronary revascularization.     

Atrial fibrillation after coronary artery bypass grafting without cardiopulmonary bypass.

OBJECTIVE: Atrial fibrillation is the most common complication after heart surgery. It rarely has a fatal outcome but causes patient instability, prolongs hospital stay, or even is the reason for perioperative infarction. Although conventional coronary artery bypass grafting (CABG) with cardiopulmonary bypass has excellent short-term and long-term results, the number of coronary operations on a beating heart without cardiopulmonary bypass is still growing. To reduce surgical trauma, off-pump coronary artery bypass grafting via sternotomy (OPCABG) or minimally invasive direct vision coronary artery bypass grafting (MIDCABG) via small thoracotomy are performed. The aim of this study was to estimate the frequency of atrial fibrillation in patients after myocardial revascularization without cardiopulmonary bypass. METHODS: A retrospective analysis of 48 patients undergoing myocardial revascularization without cardiopulmonary bypass was performed. Twenty-four patients underwent OPCABG and 24 were operated using the MIDCABG technique. The incidence of cardiac arrhythmias was analyzed since operation to the fourth postoperative day. Each patient had continuous ECG monitoring with option of arrhythmia analysis during ICU stay. After discharge from ICU 24-h ECG monitor studies were carried out. Surface 12-lead ECG was accomplished once a day, and additionally each time symptoms of cardiac arrhythmia occurred. Risk factors of atrial fibrillation were estimated. RESULTS: Atrial fibrillation occurred in 25% of patients after MIDCABG, in 29% after OPCABG, and in 18% after CABG with cardiopulmonary bypass. This difference has no statistical significance. Risk factors and incidence of postoperative complications were comparable in all groups. CONCLUSIONS: Atrial fibrillation is a common complication after procedures of myocardial revascularization, performed with or without cardiopulmonary bypass. The occurrence is not dependent on the type of operation.     

Hybrid coronary revascularization – techniques and outcome

BACKGROUND: Hybrid coronary revascularization combines minimally invasive coronary artery bypass grafting (CABG) and catheter-based coronary intervention for the treatment of multivessel coronary artery disease. This concept represents an alternative to open multivessel bypass surgery through sternotomy and to multivessel percutaneous intervention (PCI). The former is highly invasive but very effective in the long term; the latter is less invasive but results in more repeat revascularization procedures. METHODS: The surgical part of hybrid coronary intervention can be performed through thoracic mini-incisions and in completely endoscopic fashion. Robotic technology such as the daVinci ^? surgical telemanipulation system is increasingly used. Percutaneous interventions in hybrid procedures include implantation of bare metal stents and drug eluting stents. RESULTS: After 15 years of development, the literature reports mortality rates in the one percent range which may be lower than in open bypass surgery. Several studies demonstrate significantly earlier recovery and return to normal activities after hybrid intervention than after heart bypass surgery through sternotomy. Long-term follow-up studies show similar survival compared to survival after multivessel CABG and multivessel PCI. The rate of reinterventions and major adverse events, however, may be lower than after multivessel PCI, and closer to rates after open CABG. CONCLUSIONS: Hybrid revascularization represents a promising concept for treatment of coronary multivessel disease.     

Minimally Invasive Multiple Coronary Artery Bypass Grafting with Composite Graft Using in situ Right Gastroepiploic and Radial Arteries

Minimally invasive surgery/coronary artery bypass grafting (MICS CABG) via left thoracotomy and multiple CABG is a reported alternative to the standard sternotomy approach. However, harvesting the right internal thoracic artery (RITA) under direct vision requires high surgical skill. We describe MICS CABG with the left internal thoracic artery (LITA) and a composite graft using the in situ right gastroepiploic artery (GEA) and radial artery (RA) to achieve complete coronary revascularization. No complications occurred, and postoperative computed tomography showed patency of all grafts. Our experience suggests that this composite graft can be used safely and effectively in MICS CABG for complete arterial revascularization without difficulty.     

Common cardiac surgical procedures: bypass,valve repair and replacement

Cardiac surgery has undergone profound changes since Ludwig Rehn successfully repaired a right ventricular stab wound in 1896. The following century saw the rapid development of open-heart surgery, with minimally invasive surgical approaches following suit. Traditionally, sternotomy has been the incision of choice for cardiac surgical procedures, but technological advances have been applied to develop non-sternotomy, video-assisted thoracoscopic surgery (VATS) and robotic approaches. Parallel to surgical innovation, percutaneous coronary intervention (PCI) and transcatheter valve replacement procedures have offered important alternatives to surgery, currently reserved for specific patient subgroups. Despite the availability of catheter-based techniques, cardiac surgery remains relevant – the majority of our patients present with coronary artery disease or valvular pathologies and therefore coronary artery bypass graft (CABG) surgery and surgical valve replacement constitutes a substantial part of our daily practice. In this article we discuss the relevance of surgical options and highlight the most up to date surgical techniques and innovations, with a focus on the advances of minimally invasive cardiac surgery.     

Off-pump coronary artery bypass grafting: initial experience at one community hospital

BACKGROUND: This study reports one cardiac surgical center's experience with off-pump coronary artery bypass (OPCAB) and compares clinical risk factors and outcomes with a group of patients undergoing coronary artery bypass grafting (CABG) with cardiopulmonary bypass at the same institution. METHODS: Data on preoperative risk factors, intraoperative clinical markers, and postoperative outcomes were collected prospectively on all patients undergoing cardiac surgical procedures at our institution. From January 1, 1999, through October 7, 1999, 332 patients underwent OPCAB procedures at our institution. This group was compared with 445 consecutive patients undergoing CABG at the same institution during the period of January 1, 1998, through November 30, 1998. RESULTS: The two groups were similar with respect to preoperative clinical risk factors. Intraoperative data showed OPCAB patients tended to have fewer grafts performed and had a lower frequency of multiple grafts to obtuse marginal vessels. Outcomes showed no differences in the incidence of perioperative stroke, mediastinitis, reexploration for bleeding, pulmonary complications, new renal failure, postoperative atrial fibrillation, or transfusion of blood products. Patients in the OPCAB group had fewer perioperative myocardial infarctions and lower incidence of postoperative low cardiac output syndrome. A higher percentage of OPCAB patients had surgical lengths of stay of 5 days or less. The OPCAB group tended to have a lower in-hospital mortality rate but this difference did not reach statistical significance. CONCLUSIONS: Off-pump coronary artery bypass grafting with revascularization of all coronary artery segments is a safe and effective procedure that can be performed with equal or improved outcomes and shorter surgical lengths of stay compared with CABG with cardiopulmonary bypass.     

What Is Minimally Invasive Cardiac Surgery?

Most patient concerns and demands for less invasive surgery are focused on comfort, cosmesis, and rehabilitation that are all related to the degree of invasiveness. The degree of invasiveness of cardiac surgery depends on two factors: the surgical approach--the length of the skin incision, the degree of retraction and aggression to the tissue, and the loss of blood--and the use of cardiopulmonary bypass. Regarding the surgical strategy, four categories of less invasive cardiac surgery can be distinguished: (1) direct coronary artery surgery via sternotomy on the beating heart (without extracorporeal circulation); (2) limited or modified approaches using conventional techniques and instruments with either conventional cardiopulmonary bypass or the EndoCPB endovascular cardiopulmonary bypass system; (3) minimally invasive direct coronary artery bypass on the beating heart via a parasternal or left anterior small thoracotomy; and (4) true Port-Access surgery in which all surgical acts are performed through ports and the heart is arrested with the Endoaortic Clamp catheter. These categories offer different advantages in terms of reducing invasiveness and may have different learning curves. Minimally invasive cardiac surgery is undergoing an explosive evolution, and although the indications and best strategies for the different categories are yet to be determined, the trend cannot be stopped. We try to distinguish between "fashionable" strategies and those that are truly revolutionary and investments in the future.     

Robotic-assisted cardiac surgery: anesthetic and postoperative considerations

OBJECTIVE: To assess the feasibility of endoscopic telemanipulated cardiac surgery and describe the anesthetic, postoperative, and surgical implications of minimally invasive robotic-assisted cardiac surgery. DESIGN: Prospective study. SETTING: Cardiovascular and transplant center, university hospital. PARTICIPANTS: Twenty patients (13 men, 7 women) scheduled for either coronary artery bypass graft surgery or valve surgery. Mean age was 53 +/- 5 years (range, 31 to 75 years) and mean New York Heart Association class was 2.4. Three patients (6 %) were having redo procedures, and 1 patient had bacterial endocarditis. INTERVENTIONS: Surgery was done with the aid of the daVinci surgical robot (Intuitive Surgical, Mountain View, CA). Induction and maintenance of anesthesia consisted of a target-controlled infusion of remifentanil and propofol. In 11 cases (55%), cardiopulmonary bypass was performed with Port-Access technology (Heartport, Redwood City, CA), and in the remaining 9 cases (45%), conventional femorofemoral bypass was used. MEASUREMENTS AND MAIN RESULTS: Fifteen patients (75 %) were extubated within 6 hours and discharged from the cardiac surgery intensive care unit on postoperative day 1. Two patients (10%) were reexplored in the immediate postoperative period. Two conversions to thoracotomy were reported. One reoperation at 6 months and 1 late death occurred. At 1-year follow-up, excellent functional results were observed in 18 cases. CONCLUSION: Caution should be used when assessing innovative medical-surgical techniques. Despite technical difficulties and lengthy procedures, results were satisfactory. The feasibility of robotic-assisted surgery for coronary artery bypass graft and valve procedures is intuitively appealing.     

Koronare Bypasschirurgie am wachen Patienten

Patients undergoing coronary artery bypass grafting increasingly show severe co-morbidities, which can negatively affect the outcome. Recent developments in cardiac surgery have therefore focused on minimizing the invasiveness of the procedure by revascularization on the beating heart without cardiopulmonary bypass, and by reducing surgical trauma using smaller surgical incisions. Progress in minimally invasive cardiac surgery has led to minimally invasive anesthesia, i.e. using high thoracic epidural anesthesia as the sole technique in the conscious patient (awake coronary artery bypass grafting, ACAB). Published data on ACAB procedures in smaller cohorts have demonstrated that the procedure is safe. Significant complications occurred in 7.1% of patients. A particular cause of concern during ACAB surgery is the development of spinal epidural hematoma the risk of which has been estimated to be as high as 1:1,000. A thorough risk-benefit analysis has therefore to be made. Currently, ACAB surgery remains limited to few specialized centers and highly selected patients.     

Effects of coronary artery bypass grafting on cellular immunity with or without cardiopulmonary bypass: changes in lymphocytes subsets

Cell-mediated immunity responses decrease after all kinds of surgical procedures. Either anesthesia or surgical trauma plays an important role in this effect. Identification of functional lymphocyte subsets, by using appropriate monoclonal antibodies and analysis of flow cytometry data, appears to provide an accurate measurement of cellular immune competence. We found a significant decrease in the total number of T helper/inducer cells (p<0.035), B cells (p<0.043) and natural killer cells (NK) (p<0.018) but in contrast, increase in NK cell activity (p<0.012) in the peripheral arterial blood of ten patients undergoing coronary artery bypass grafting with cardiopulmonary bypass (group 1) immediately after surgery and postoperative day 1 (POD1). On the other hand, there was no significant change of these parameters occurred in the peripheral arterial blood of ten patients (group 2) who were undergoing coronary artery bypass grafting without cardiopulmonary bypass. Therefore, we conclude that coronary artery bypass grafting (CABG) with cardiopulmonary bypass induce a greater decrease in immunologic response than CABG without cardiopulmonary bypass (off pump) operations. Nevertheless, off pump CABG operations do not induce a greater decrease in immunologic response than other surgical operations.     

Is there an optimal minimally invasive technique for left anterior descending coronary artery bypass?

Background  

The aim of this retrospective study was to evaluate the clinical outcome of three different minimally invasive surgical techniques for left anterior descending (LAD) coronary artery bypass grafting (CABG): Port-Access surgery (PA-CABG), minimally invasive direct CABG (MIDCAB) and off-pump totally endoscopic CABG (TECAB).     

Two cases of minimally invasive reoperative coronary artery bypass

Reoperative coronary artery bypass grafting (CABG) are still associated with higher mortality than primary CABG. This is due in part to the potential for cardiac and patent graft injury during their dissection and the reopening of the sternum. Therefore, in two patients with recurrent angina attributable to occulusion of the old vein graft to the LAD, we performed reoperative CABG by the minimally invasive direct coronary artery bypass (MIDCAB) procedures. The left internal thoracic artery was anastomosed to the LAD through small anterolateral thoracotomy without cardiopulmonary bypass. Both patients recovered fast and underwent postoperative angiogram, showing the new grafts widely patent. About two weeks later, both discharged in the conditiions of nearly normal activities. The reoperative MIDCAB grafting might be expected to be as safe and promissing as the primary one.     

Minimally Invasive Direct Coronary Artery Bypass Surgery with Right Gastroepiploic Artery for Redo Patients

Coronary artery bypass grafting (CABG) has been widely performed for coronary artery disease. Therefore, cases requiring reoperative CABG are increasing. We performed a minimally invasive direct coronary artery bypass (MIDCAB) procedure on four patients, as reoperative CABG surgery for the right coronary artery (RCA), employing the right gastroepiploic artery (RGEA). The target sites were the distal RCA in two patients and the posterior descending (PD) branch in the other two. Complete revascularization was accomplished in all patients without sternotomy, cardiopulmonary bypass (CPB), or blood transfusion. The mean operative time was 3.0 h (range: 2.4–3.7 h). Postoperative coronary angiography showed all grafts to be patent. All patients were discharged without postoperative complications and remained free from cardiac events during a mean follow-up period of 1.5 years (range: 0.5–3.0 years). MIDCAB for the RCA, employing the RGEA via a subxiphoid incision showed, excellent revascularization in redo CABG cases. This technique is a safe and effective method for redo cases.     

Off-pump coronary surgery: how do the anesthetic considerations differ?

In recent years, there has been much interest in performing coronary artery bypass graft (CABG) surgery without the aid of cardiopulmonary bypass (CPB). Initial efforts focused on "minimally invasive" direct coronary artery bypass, wherein the left anterior descending artery is bypassed with an in situ left internal mammary artery graft through a small left anterior thoracotomy. A more widely adopted approach however, is off-pump CABG (OPCAB), in which CABG surgery is performed on one or more vessels through the usual median sternotomy approach without the aid of CPB. This article reviews the differences in the anesthetic considerations of OPCAB compared to conventional CABG using CPB.