Anaesthesia for minimally invasive cardiac surgery

Minimally invasive cardiac surgery is used for both extracardiac and intracardiac procedures. Extracardiac procedures, such as coronary artery bypass grafting, are often performed on a beating heart. Intracardiac procedures are done with the aid of cardiopulmonary bypass. The surgery is performed via a minithoracotomy or a ministernotomy. Thoracoscopic video-assisted surgery, often with robotic assistance, necessitates prolonged one-lung ventilation to optimize exposure. Port-access surgery will require appropriate positioning of various catheters to establish cardiopulmonary bypass. Adequate flow during cardiopulmonary bypass may require suction augmentation of venous return and may increase the risk of air emboli. Limited exposure of the heart during surgery poses challenges with management of arrhythmia, haemostasis, myocardial protection and de-airing at the end of surgery. Patient selection is important to avoid intra-operative and post-operative complications. Prolonged single-lung ventilation, incomplete revascularization in hybrid procedures, and limited access for rapid intervention pose challenges with patient management. Conversion to sternotomy that may be required occasionally and extension of portals over several dermatomal segments mandate a versatile analgesic technique.     

Minimally invasive cardiac surgery: surgical techniques and anesthetic problems]

OBJECTIVE: To review current data on minimally invasive cardiac surgery. DATA SOURCES: Search through the Medline data base of French or English articles. DATA EXTRACTION: The articles were analysed to make a synthesis of the various techniques with their main indications and contra-indications. DATA SYNTHESIS: Minimally invasive cardiac surgery includes various surgical procedures. The usual techniques are described, their major benefits and drawbacks are discussed. The main goals of anaesthetic management are preservation of ventricular function and systemic perfusion, detection and treatment of myocardial ischaemia, prevention of hypothermia in case of coronary artery bypass grafting on the beating heart via sternotomy, intermittent selective ventilation of the collapsed lung using CPAP in case of limited thoracotomy. Expertise in transoesophageal echocardiography is essential for insertion and checking the accurate positioning of the various catheters of the endovascular CPB Heartport system (pulmonary vent, endosinus catheter, venous cannula, endoaortic clamp) allowing coronary artery bypass grafting and mitral valve surgery through limited thoracotomy and finally, detection of retained intracardiac air and assessment of complete clearing of cardiac cavities after mitral valve surgery through limited thoracotomy and aortic valve surgery via ministernotomy. Short-acting anaesthetic agents allow rapid recovery from anaesthesia, early extubation and discharge to the surgical ward within 24 h, whereas overall time spent in the operating room is often longer than with conventional cardiac surgery.     

Intensive imaging assessment for successful minimally invasive cardiac surgery

To clarify special imaging assessment that is useful for minimally invasive cardiac surgery (MICS), we examined 141 cases of MICS operations with ministernotomy or minithoracotomy. In the 141 patients, 62 valve, 42 coronary, 37 congenital heart, and 2 other procedures were successfully completed without conversion to full sternotomy. Preoperative chest x-ray, computed tomography, and/or magnetic resonance imaging were necessary for determining the level of ministernotomy, especially in aortic valve operations. Transthoracic echocardiography was useful for selecting procedures of mitral valve or intracardiac repair through the MICS approach. Intraoperative transesophageal echocardiography was essential for continuous monitoring of cardiac function, intracardiac flow, air bubbles, and so forth. The above results suggest that intensive imaging assessment might be very important for successful MICS operations with ministernotomy or minithoracotomy and that extensive indications for this technique exist for various cardiovascular diseases.     

机器人微创非体外循环冠状动脉旁路移植术

目的 评价da Vincis机器人系统进行胸廓内动脉(IMA)游离、小切口非体外循环下冠状动脉旁路移植术的安全性和手术效果.方法 2007年1月到2011年3月,105例患者接受机器人IMA游离、小切口非体外循环下冠状动脉旁路移植术.其中男性77例,女性28例,年龄33～77岁,平均(59±10)岁.患者术前行64排CT检查评估IMA质量,2例患者左LIMA纤细或走行异常弃用.术者于操作台前、三维成像系统下遥控机器人游离IMA并完成动脉桥与靶血管的徒手吻合.其中4例患者旁路移植后接受了杂交技术于回旋支或右冠状动脉行支架植入术.术中均以超声血流检测仪测量桥血管的波形及血流.术后以冠状动脉造影或64排CT评估桥血管的通畅性,并进行随访.结果 所有患者成功接受上述手术,无手术死亡病例.术中平均IMA血管桥血流量为(21±13) ml/min.1例于术后第1天突发心跳骤停经抢救后痊愈,复查桥血管通畅.1例合并脑梗死患者术后肺部感染,痊愈后出院.其余患者无并发症发生.术中及术后出血少,术后恢复快.随访1～51个月,平均(30±12)个月.术后冠状动脉造影或64排CT复查未见桥血管狭窄或闭塞,心绞痛症状缓解.结论 机器人IMA游离、小切口非体外循环冠状动脉旁路移植术创伤小、疗效确切、安全性好,是微创冠状动脉再血管化的重要方向之一.     

A method for mediastinal drainage after cardiac procedures using small silastic drains

BACKGROUND: It has been standard teaching in cardiac surgery that drainage of the mediastinum following cardiac surgical procedures is best accomplished using rigid large-bore chest tubes. Recent trends in cardiac surgery have suggested less invasive approaches to a variety of diseases. Difficult drainage problems in the field of general surgery including hepatic and pancreatic collections have been drained successfully with smaller flexible drains for many years. Additionally, many difficult to reach collections in the chest have been drained by invasive radiologists using small pigtail catheters. METHODS: We have introduced drainage of the mediastinum using 10-mm flexible, flat, fluted Blake drains. To date, we have used these drains in more than 100 cardiac operations including coronary artery bypass grafting, valve repair/replacements, combined coronary artery bypass grafting/valve operations, heart transplants, septal defects, and mediastinal tumors. RESULTS: We have demonstrated that this form of drainage is as good as using large-bore chest tubes with no significant risk of bleeding or tamponade. Additionally, use of these tubes is less painful, allows more mobility, and earlier discharge with functioning drains in place if necessary. CONCLUSIONS: Larger chest tubes are not necessarily better when it comes to draining the mediastinum. The actual area of ingress through the sideholes is considerably less than the surface area provided by the fluted Blake drain. We believe that this system can replace standard chest tubes.     

Living with off-pump coronary artery surgery: evolution, development, and clinical potential for coronary heart disease patients

The enormous progress in interventional cardiology during the last 10 years has resulted in a major change in the spectrum of patients referred for coronary bypass surgery. These patients are older and sicker and frequently have had previous percutaneous coronary interventions. Consequently, cardiac surgery is responding by adding new surgical techniques: off-pump open-chest coronary bypass surgery (OPCAB), minithoracotomy bypass surgery, videothoracoscopic (robotic) procedures, etc. Several registries published to date have proved OPCAB to be safe and clinically effective. Randomized studies and meta-analysis research in this field provide scientific support and suggest that myocardial, renal, and neurological functions, amongst others, are better preserved by OPCAB than by classic techniques that use a cardiopulmonary bypass pump (CPB). Moreover, avoidance of CPB yields significantly reduced oxidative stress and systemic inflammatory response. This results in higher safety for ischemic heart disease patients undergoing revascularization, thus offsetting the propensity to lower costs. The present review examines the physiological advantages and clinical outcomes of this simple mode of myocardial revascularisation and evaluates the wider implications arising from its evolution.     

Cardiopulmonary bypass

Cardiopulmonary bypass is an essential component of many cardiac surgical procedures, temporarily taking over the function of the heart and lungs during surgery. Components of the bypass circuit are described and the preparation for and management of bypass outlined. Cross clamping the ascending aorta risks causing myocardial ischaemia, which is prevented by use of a cardioplegic solution to stop the heart from beating or an ‘intermittent cross clamp fibrillation’ technique. Blood conversation is provided by suckers, vents and red blood cell salvage. Safety, side effects and associated therapies are discussed.     

Hemodynamic changes during cardiac manipulation in off-CPB surgery: relevance in brain perfusion

The recent introduction of various cardiac stabilization and positioning devices, alone or in combination with deep pericardial traction sutures, has greatly increased the ability to perform beating heart surgery to accomplish multi-vessel coronary revascularization without the need for cardiopulmonary bypass (CPB), with its associated risks. However, positioning the heart for anastomosis of the circumflex (Cx) and the posterior descending artery poses a risk of inducing hypotension, impaired cardiac output, and generalized hemodynamic instability with risk of cerebral compromise. This report discusses clinical studies suggesting that compromised right ventricular diastolic filling as a result of direct ventricular compression, rather than impaired contractility or ischemia, may be the primary mechanism for producing hemodynamic instability during OPCAB surgery. Foremost among measures to minimize ventricular compression is optimal placement of the myocardial stabilization device. Secondary measures include steep Trendelenburg positioning, fluid loading, right-sided pleuro-pericardial window that allows rotation of the heart by partial herniation into the right pleural cavity, and possibly certain pharmacological agents. This report also analyzes the effect that variable degrees of hemodynamic disturbance accompanying displacement of the heart for OPCAB surgery has on endorgan perfusion and considers the effects of hypotensive agents, direct cerebral dilators, and patient-specific factors on cerebral blood flow. The role of the partial aortic occlusion clamp and risk of stroke is also considered. We conclude that for cardiac surgery patients considered at increased risk of adverse central nervous system events, direct monitoring of cerebral function and avoidance of aortic manipulation is strongly recommended.     

Intracardiac knotting of a Swan-Ganz catheter. Detection using intraoperative trans-esophageal echocardiography]

Transoesophageal echocardiography is a new technique that allows continuous and noninvasive assessment of cardiac function during surgery. More recently this technique is being used to detect the presence of external objects into the cardiac cavities. We report a case of Swan-Ganz catheter knotting confirmed by this echocardiography technique. He was a 57 year old male with previous history of arterial hypertension and ischemic heart disease who was scheduled for surgery because poor response to medical therapy. After anesthetic induction a thermodilution catheter was introduced percutaneously into the right internal jugular vein under continuous pressure monitoring from the distal catheter hole. In view of the difficulties in introducing the catheter into the pulmonary artery an intravascular catheter knotting was suspected and a bidimensional transesophageal echocardiogram confirmed the diagnosis. During extracorporeal circulation the catheter was withdrawn through a right auriculotomy. Monitoring with a Swan-Ganz catheter, as other invasive monitoring techniques, is followed by a certain degree of complications which should be avoided by a careful manipulation. Echocardiography is a valuable diagnostic procedure to identify the position of monitoring catheters into the cardiac cavities.     

Excision of a left atrial myxoma via a minimally-invasive technique: a possible routine access

We would like to present our experience of surgical excision of intracardiac tumors using a video-assisted minimally-invasive cardiac surgery (MIC) technique. An 83-year-old female patient received video-assisted cardiac surgery for excision of a left atrial tumor. The surgery was performed through a right anterior submammary minithoracotomy and guided by video-assisted endoscopic techniques by projected images on a video monitor while under femoro-femoral bypass. The myocardium was protected by single-dose antegrade crystalloid cardioplegia. The tumor was excised completely recording a 61-minute bypass time and a 103-minute total operative time. Histopathological examination revealed left atrial myxoma. Transthoracic echocardiography examination showed good ventricular function and the absence of residual tumors. The patient was satisfied by the cosmetic healing of the wound and was discharged eight days after the surgery. Video-assisted MIC surgery is technically feasible and could be applied as a routine access in all left atrial tumors without the fear of inadequate intraoperative exposure and its drawbacks.     

Renal insufficiency after cardiac surgery

The new millennium ushered in a number of changes in cardiac surgery. Off-pump coronary artery bypass surgery became technically easier so that multivessel surgery became less of a challenge and cardiologists were supplied with new catheters that accessed lesions that were previously thought of as being unapproachable. New drugs were introduced that made the management of heart failure patients feasible on an outpatient basis, and new devices extend the bridging period to transplantation. However, these advances have not necessarily been attended by significant improvements in outcome, possibly because the less challenging a procedure becomes, the sicker the patients that can be managed. This observation is particularly true with the incidence and outcome of renal failure after cardiac surgery. Bypass factors have been manipulated without much effect, and the traditional drugs that were found to increase renal blood flow in animal experiments did not translate into clinical improvement in renal outcome. Recent research has given us insight into the pathophysiology of ischemic acute renal failure, and it has been found that the paradigm was not as simple as previously thought, possibly accounting for the failure of the more traditional renal drugs (dopamine, mannitol and diuretics). However, these new insights open up the possibility of novel targets for renal protection and repair.     

Impact of off-pump coronary artery surgery on myocardial performance and beta-adrenoceptor function

OBJECTIVE: To determine the hemodynamic changes during beating heart revascularization of the left anterior descending artery, the circumflex artery, and the right coronary artery as well as cardiovascular beta-adrenoceptor function before and after off-pump coronary artery bypass surgery. DESIGN: Prospective study. SETTING: University department of cardiothoracic anesthesia. PARTICIPANTS: Twenty patients scheduled for off-pump coronary artery bypass surgery using the Octopus 2 stabilizer system. INTERVENTIONS: Isoproterenol, 4 microg, was administered intravenously after induction of anesthesia and again after surgery to monitor cardiac beta-receptor function. MEASUREMENTS AND MAIN RESULTS: The hemodynamic responses to isoproterenol and cardiovascular variables were monitored before, during, and after immobilization of the target coronary artery with catheters in the radial and pulmonary arteries. During surgery on the left anterior descending artery (n = 23), stroke volume and cardiac index decreased 17 mL (21%) and 400 mL (17%). During revascularization of the circumflex artery (n = 9), stroke volume and cardiac index decreased 19 mL (28%) and 300 mL (17%). During surgery on the posterior aspect of the heart (n = 13), stroke volume and cardiac index decreased 22 mL (29%) and 400 mL (17%). All the cardiovascular variables had returned to baseline values 5 minutes after releasing the heart. The hemodynamic responses to isoproterenol were equal before and after surgery. CONCLUSION: This study provides evidence that the hemodynamic changes associated with off-pump surgery on the 3 major coronary arteries are similar and of short duration. No desensitization of cardiovascular beta-adrenoceptors was found. This finding is in contrast to the deterioration in beta-adrenoceptor function seen after surgery with cardiopulmonary bypass.     

Minimally invasive technology for mitral valve surgery via left thoracotomy: experience with forty cases

BACKGROUND: Recent evolution of minimally invasive technology has expanded the application of the right thoracotomy approach for mitral valve surgery. These same technological advances have also made the left posterior minithoracotomy approach attractive in complex mitral procedures. METHODS: From 1996 to 2003, 921 isolated mitral valve procedures were performed without sternotomy; 40 (4.3%) of these were performed via left posterior minithoracotomy. In the left posterior minithoracotomy group, ages ranged from 18 to 84 years; 36 patients had had previous cardiac surgery (9 on > or =2 occasions). Other factors precluding right thoracotomy included mastectomy/radiation and pectus excavatum. RESULTS: Arterial perfusion was via femoral artery (n = 26) or descending aorta (n = 14); long femoral venous cannulas with vacuum-assisted drainage were used in 39 procedures. Two patients had direct aortic crossclamping, 18 had hypothermic fibrillation, and 20 had balloon endoaortic occlusion. The mean crossclamp and bypass times were 81.9 and 117.2 minutes, respectively. Hospital mortality was 5.0% (2/40); both deaths occurred in octogenarians. There were no injuries to bypass grafts or conversions to sternotomy. Complications included perioperative stroke (2/40; 5.0%), bleeding (2/40; 5.0%), and respiratory failure (1/40; 2.5%); 28 patients (70%) had no postoperative complications. There was no incidence of perioperative myocardial infarction, renal failure, sepsis, or wound infection. The median length of stay was 7 days. CONCLUSIONS: Advances in minimally invasive cardiac surgery technology are readily adaptable to a left-sided minithoracotomy approach to the mitral valve. The left posterior minithoracotomy approach is a valuable option in complicated reoperative mitral procedures with acceptable perioperative morbidity and mortality.     

Clinical study of centrifugal pump bypass as an auxiliary technique for surgical treatment of descending thoracic aorta

Left heart bypass or arterial bypass using a centrifugal pump (Bio-pump bypass) with a H-PSD shunt tube was performed as an auxiliary technique for the treatment of descending thoracic aorta in 13 cases. Hemodynamic differences during aortic clamp were compared between cases using Bio-pump bypass and 4 cases of axillo-femoral temporary bypass which were carried out in the first term. Furthermore, in Bio-pump bypass cases, the bypass route was investigated from the point of view of operative complications in relation to bypass technique. Peripheral blood pressure and urinary output during aortic clamp were significantly increased in the Bio-pump bypass group. Those results indicated that the Bio-pump bypass was useful as an auxiliary technique especially for high risk patients with low renal function. In particular, left heart bypass was a beneficial technique which was not affected by modality or region of disorder in the descending thoracic aorta. However, this technique should be selected carefully for patients with cardiac disease, for instance severe left ventricular hypertrophy, because two cases of operative complications consisting of pericardial effusion related to the bypass technique were experienced in this study.     

Evidence of cortisol suppression in neonates after major cardiac surgery: is supplementation necessary?

Introduction:  Infants and children undergoing major cardiac surgery mount a substantial stress response. Data from a previous investigation suggested that after cardiac surgery infants under 90 days had prolonged suppression of cortisol production (1) that might not be explained as simply due to the use of dexamethasone (used routinely for cardiopulmonary bypass). This study was designed to determine the origins of this suppressed cortisol response.
Methods:  Local ethics committee approval was granted for the study. Ten neonates due to undergo cardiac surgery using cardiopulmonary bypass were recruited after informed parental consent. A standard anaesthetic technique was used. Baseline blood samples were taken following induction of anaesthesia and arterial line insertion: a dose of dexamethasone (0.5 mg·kg^-1) was then administered as per usual protocol. Blood was taken at release of the cross clamp (ROCC) and then 2, 6, 24, 48 and 72 h later. Blood was not taken at 72 h if the patient no longer had invasive monitoring lines in place. At each time point concentrations of cortisol, adrenocorticotrophic hormone (ACTH) and dexamethasone were measured.   Results:   

     

Postoperative intensive care in infants and children after cardiac surgery

Background The postoperative course of infants and children after open heart surgery is often complicated by cardiopulmonary insufficiency or low cardiac output. Methods From January 1989 to April 1992 441 infants and children with congenital heart disease underwent cardiac surgery. 128 of these patients (29%) required prolonged or extensive intensive care because of cardiopulmonary insufficiency or low cardiac output. Aortic cross clamp and cardiopulmonary bypass times were measured in all patients. In the postoperative period duration of mechanical ventilation, duration of intensive care, special monitoring and therapeutic strategies and clinical scores were documented. Results The overall mortality rate was 9.9%, the mortality rate in patients with postoperative cardiopulmonary insufficiency or low cardiac output was 34%. The mortality rate increased significantly up to 73% when the cardiopulmonary bypass time exceeded 200 min. Mean duration of intensive care of survivors (S) and nonsurvivors (NS) was 10.3±0.8 and 4.1±1.2 days, respectively (p<0.01), mean duration of mechanical ventilation was 7.1±0.5 (S) and 4.1±1.2 (NS) days, respectively (p<0.01). NS had a significantly higher degree of physiologic derangement assessed by the Acute Physiologic Score for Children and needed more monitoring and therapeutic interventions assessed by the Therapeutic Intervention Scoring System than S. Conclusion Complex cardiac surgery, a cardiopulmonary bypass time over 200 min, high catecholamine infusion rates combined with a persisting low mean arterial pressure are associated with a high postoperative mortality rate in infants and children with congenital heart defects.     

Beating Heart Video-Assisted Mitral Valve Surgery: A Useful Technique for High-Risk Patients

Abstract   Background: Beating-heart valve surgery through a sternotomy has been used as an excellent myocardial protection strategy in high risk patients. Minimally invasive approaches have reduced the trauma and enhanced the recovery of patients undergoing heart surgery. We hypothesized that high-risk patients undergoing mitral valve surgery will benefit from a combination of these two approaches. Methods: A 52-year-old male with dilated cardiomyopathy and left ventricular function of 15% was referred for surgery because of congestive heart failure. Results: Using a 4-cm right minithoracotomy and femoral cannulation for cardiopulmonary bypass, successful beating-heart video-assisted mitral valve repair was performed. The adequacy of myocardial protection was confirmed by absence of ischemic electrophysiologic changes. The patient was discharged home on the 6^th postoperative day. Conclusion: Beating-heart strategy can be combined with a minimally invasive approach in patients with severely reduced ventricular function, who require mitral valve surgery.     

Right posterior-lateral minithoracotomy access for treating congenital heart disease

A modified right posterior-lateral minithoracotomy with the aid of peripheral cardiopulmonary bypass is a surgical option that has been adopted in our institution in selected patients with simple congenital heart disease. We present our selection criteria, describe our technique, and analyze our results with this modified technique.     

Cardiopulmonary bypass in conscious patients undergoing cardiac surgery

This study was undertaken to evaluate the feasibility of thoracic epidural anesthesia as an alternative technique to general anesthesia in patients undergoing cardiac surgery under cardiopulmonary bypass. This prospective study was conducted in a tertiary referral hospital. Seventeen patients underwent cardiac surgical procedures requiring cardiopulmonary bypass without general anesthesia under thoracic epidural anesthesia from February to May 2004. An epidural catheter was inserted at any of intervertebral spaces from C7 to T2 on the day before surgery. Subsequently, cardiac surgery was performed under normothermic cardiopulmonary bypass, during which the patients remained conscious. The types of surgery included closure of atrial septal defects, valve replacements, and combined bypass surgery and valve replacements. Approach to the heart was obtained through midsternotomy. Anticoagulation was achieved with 300 units/kg of heparin. Normothermic cardiopulmonary bypass was initiated slowly during the course of 10 to 15 min. Nonpulsatile flow was administered using centrifugal pump and mean perfusion pressure was maintained in the range of 70-80 mmHg. The planned surgical procedure could be performed in all the patients. Soon after establishing cardiopulmonary bypass, the patients developed apnea, which reverted to normalcy a few minutes after disconnection of cardiopulmonary bypass. The mean time for cardiopulmonary bypass was 102 +/- 28 min, aortic cross clamp time was 58 +/- 28 min, and the total duration of surgery was 229 +/- 64 min. None of the patients required conversion to general anesthesia. There was no mortality or morbidity in this series and to our knowledge our series is the first such. Cardiac surgical procedures requiring cardiopulmonary bypass may be conducted under thoracic epidural anesthesia, without endotracheal general anesthesia.     

Minimally Invasive Approach for Redo Mitral Valve Surgery: A True Benefit for the Patient

ABSTRACT Objectives Redo mitral valve surgery via sternotomy is associated with a substantial morbidity and mortality. This study evaluated a minimally invasive technique for mitral valve redo procedures. Material and Methods: Out of a series of 394 patients undergoing mitral valve repair or replacement via a right minithoracotomy, 39 patients underwent redo mitral valve surgery (59 ± 13 years, 23 female). Previous cardiac surgeries included 17 patients with mitral valve repair, 6 patients with mitral valve replacement, 3 patients with aortic valve replacement, 2 patients with atrial septal defect closure, and 11 patients with coronary artery bypass grafting (CABG). In all cases, femoro-femoral cannulation was performed. The port access technique was applied in patients undergoing redo valve surgery. In patients with prior CABG, the operation was performed using deep hypothermia and ventricular fibrillation. Results: In all cases, sternotomy was avoided. The mitral valve was replaced in 20 patients and repaired in 19. Time of surgery and cross-clamp time were comparable with the overall series (168 ± 73 [redo] vs 168 ± 58 min and 52 ± 21 [redo] vs 58 ± 25 min). Mortality was 5.1%. One patient had transient hemiplegia due to the migration of the endoclamp. All other patients had uneventful outcomes and normal mitral valve function at 3-month's follow-up. Conclusion: Redo mitral valve surgery can be performed safely using a minimally invasive approach in patients with a previous sternotomy. The right lateral minithoracotomy offers excellent exposure. It minimizes the need for cardiac dissection, and thus, the risk for injury. Avoiding a resternotomy increases patient comfort of redo mitral valve surgery.