Hemodynamics and gas exchange during carbon dioxide insufflation for totally endoscopic coronary artery bypass grafting

Thoracoscopic Approach to Epicardial Lead Implantation in Adult Patients with Previous Congenital Cardiac Surgery

Background

Substantial technical challenges exist in placing transvenous pacing leads in the heterogeneous adult congenital heart disease patient population. Anatomical issues including occlusion of central veins, single ventricle physiology, and lack of transvenous access to systemic right ventricles, often require thoracotomy for epicardial lead placement.

Methods

We assessed the feasibility of performing a totally thoracoscopic approach to epicardial pacing lead implantation in 10 adult patients (mean age 32.5 years) with congenital heart disease. The underlying cardiac anatomy consisted of transposition of the great arteries, status post (s/p) Mustard procedure (3); tricuspid atresia, s/p Fontan procedure (3); congenitally corrected transposition (1); Ebstein's anomaly, s/p tricuspid valve replacement (1); AV canal, s/p repair (1); and hypertrophic cardiomyopathy, s/p myomectomy (1). Twenty-six previous cardiac operations (mean 2.8 per patient) had been performed in this group.

Results

Indications for thoracoscopic lead insertion included primary rhythm disturbances, progressive heart failure with a QRS>120 milliseconds, and an unapproachable coronary sinus or failed transvenous lead insertion. All patients underwent thoracoscopic implantation of 2 epicardial leads to the systemic ventricle and generator insertion. Intraoperative transesophageal echocardiography (TEE) was used in all cases, which facilitated port placement. Measurements at operation showed mean threshold of 2.0V (95% CI 0.9–3.1V at 0.5 milliseconds) and a mean impedance of 1259 Ohms (95% CI 418–2100). There were no procedural related complications and no patient required conversion to an open procedure. Seventy percent of patients were extubated immediately after the procedure and were discharged from the intensive care unit within 24 hours. There was 1 noncardiac death due to gastrointestinal ischemia.

Conclusion

Adults with congenital heart disease present significant challenges to pacing lead implantation including variability of the location of the systemic ventricle, coronary sinus anatomy, right-sided valve replacement, a small thoracic cavity, limited vascular access, and adhesions from prior cardiac procedures. Additionally, thoracoscopy has been previously considered a contraindication in this subgroup of patients. However, we have demonstrated that with careful preoperative planning and the assistance of TEE, a totally thoracoscopic approach to epicardial lead implantation is both feasible and safe.

Optimal PEEP during one-lung ventilation with capnothorax: An experimental study

BACKGROUND

One-lung ventilation (OLV) with induced capnothorax carries the risk of severely impaired ventilation and circulation. Optimal PEEP may mitigate the physiological perturbations during these conditions.

METHODS

Right-sided OLV with capnothorax (16 cm H₂ O) on the left side was initiated in eight anesthetized, muscle-relaxed piglets. A recruitment maneuver and a decremental PEEP titration from PEEP 20 cm H₂ O to zero end-expiratory pressure (ZEEP) was performed. Regional ventilation and perfusion were studied with electrical impedance tomography and computer tomography of the chest was used. End-expiratory lung volume and hemodynamics were recorded and.

RESULTS

PaO₂ peaked at PEEP 12 cm H₂ O (49 ± 14 kPa) and decreased to 11 ± 5 kPa at ZEEP (P < 0.001). PaCO₂ was 9.5 ± 1.3 kPa at 20 cm H₂ O PEEP and did not change when PEEP step-wise was reduced to 12 cm H₂ O PaCO_2. At lower PEEP, PaCO₂ increased markedly. The ventilatory driving pressure was lowest at PEEP 14 cm H₂ O (19.6 ± 5.8 cm H₂ O) and increased to 38.3 ± 6.1 cm H₂ O at ZEEP (P < 0.001). When reducing PEEP below 12-14 cm H₂ O ventilation shifted from the dependent to the nondependent regions of the ventilated lung (P = 0.003), and perfusion shifted from the ventilated to the nonventilated lung (P = 0.02).

CONCLUSION

Optimal PEEP was 12-18 cm H₂ O and probably relates to capnothorax insufflation pressure. With suboptimal PEEP, ventilation/perfusion mismatch in the ventilated lung and redistribution of blood flow to the nonventilated lung occurred.

Hybrid myocardial revascularization

Background

In patients with advanced coronary artery disease (CAD), coronary artery bypass grafting (CABG) is associated with improved long-term outcomes while percutaneous coronary intervention (PCI) is associated with lower periprocedural complications. A new approach has emerged in the last decade that attempts to reap the benefits of bypass surgery and stenting while minimizing the shortcomings of each approach, hybrid myocardial revascularization (HMR).Three strategies for timing of the hybrid revascularization exists, each with their own inherent advantages and shortcomings: (1) CABG followed by PCI, (2) PCI followed by CABG, or (3) simultaneous CABG + PCI in a hybrid suite.

Studies

The results of the first randomized control trial comparing HMR (CABG first) and standard CABG, POL-MIDES (Prospective Randomized PilOt Study EvaLuating the Safety and Efficacy of Hybrid Revascularization in MultIvessel Coronary Artery DisEaSe), show HMR was feasible for 93.9% of patients whereas conversion to standard CABG was required for 6.1%. At 1 year, both groups had similar all-cause mortality (CABG 2.9% vs. HMR 2%) and major adverse clinical event (MACE)-free survival rates (CABG 92.2% vs. HMR 89.8%). Results of observational and comparative studies show that minimally invasive HMR procedures in patients with multivessel CAD carry minimal perioperative mortality risk and low morbidity and do not increase the risk of postoperative bleeding. The advantage they offer in comparison to classical surgical revascularization is indeed faster rehabilitation and patient's return to normal life.

Conclusion

Hybrid myocardial revascularization has been developed as a promising technique for the treatment of high-risk patients with CAD. Hybrid revascularization using minimally invasive surgical techniques combined with PCI offers to a part of patients an advantage of optimal revascularization of the most important artery of the heart, together with adequate myocardial revascularization in a relatively delicate way. Indeed, to patients with high operative risk of standard surgery, it offers an alternative which should be considered carefully.

Difficult Management of a Double-Lumen Endotracheal Tube and Difficult Ventilation during Robotic Thymectomy with Carbon Dioxide Insufflation

Robotic surgery with carbon dioxide (CO₂) insufflation to the thorax is frequently performed to gain a better operative field of view, although its intraoperative complications have not yet been discussed in detail. We treated two patients with difficult ventilation caused by distal migration of a double-lumen endotracheal tube (DLT) during robotic thymectomy. In the first case, migration of the DLT during one-lung ventilation (OLV) occurred after CO₂ insufflation to the bilateral thoraxes was started. Oxygenation rapidly deteriorated because dependent lung expansion was restricted by CO₂ insufflation. In the second case, migration of the DLT during OLV occurred while CO₂ insufflation to a unilateral thorax and mediastinum was performed. In both cases, once migration of the DLT during OLV occurred with CO₂ insufflation, readjusting the DLT became very difficult because our manipulation of bronchofiberscopy was prevented by the robot arms located above the patient's head and because deformation of the trachea/bronchus induced by CO₂ insufflation caused a poor image of the bronchofiberscopic view. Thus, during robotic-assisted thoracoscopic surgery with CO₂ insufflation, since there is a potential risk of difficult ventilation with a DLT and since readjustment of the DLT is very difficult, discontinuing CO₂ insufflation and switching to double-lung ventilation are needed in such a situation.

Anesthetic challenges in minimally invasive cardiac surgery: Are we moving in a right direction?

Continuously growing patient's demand, technological innovation, and surgical expertise have led to the widespread popularity of minimally invasive cardiac surgery (MICS). Patient's demand is being driven by less surgical trauma, reduced scarring, lesser pain, substantially lesser duration of hospital stay, and early return to normal activity. In addition, MICS decreases the incidence of postoperative respiratory dysfunction, chronic pain, chest instability, deep sternal wound infection, bleeding, and atrial fibrillation. Widespread media coverage, competition among surgeons and hospitals, and their associated brand values have further contributed in raising awareness among patients. In this process, surgeons and anesthesiologist have moved from the comfort of traditional wide incision surgeries to more challenging and intensively skilled MICS. A wide variety of cardiac lesions, techniques, and approaches coupled with a significant learning curve have made the anesthesiologist's job a challenging one. Anesthesiologists facilitate in providing optimal surgical settings beginning with lung isolation, confirmation of diagnosis, cannula placement, and cardioplegia delivery. However, the concern remains and it mainly relates to patient safety, prolonged intraoperative duration, and reduced surgical exposure leading to suboptimal treatment. The risk of neurological complications, aortic injury, phrenic nerve palsy, and peripheral vascular thromboembolism can be reduced by proper preoperative evaluation and patient selection. Nevertheless, advancement in surgical instruments, perfusion practices, increasing use of transesophageal echocardiography, and accumulating experience of surgeons and anesthesiologist have somewhat helped in amelioration of these valid concerns. A patient-centric approach and clear communication between the surgeon, anesthesiologist, and perfusionist are vital for the success of MICS.

Clinical outcomes of CO2-less single-port video-assisted thoracoscopic thymectomy versus open thymectomy: comparative study

BACKGROUND

Although video-assisted thoracoscopic surgery (VATS) for thymic disorders has been introduced, its oncological outcome and benefits over others open approaches remains unclear. Single-port VATS thymectomy using a flexible port and CO₂ has been described. However, VATS thymectomy is possible by a single incision of 3 cm without CO₂ insufflation or special port device avoiding objections related to CO₂ insufflation and allowing instruments to move more freely making procedure easier and cheaper. Our institutional experience in open and CO₂-less VATS single-port thymectomy was retrospectively reviewed to evaluate compared to sternotomy, the clinical and oncological outcomes with this novel approach.

METHODS

A retrospective review consisting of 84 patients who underwent thymectomy because different thymic disorders especially thymoma was performed. Eighteen patients underwent CO₂-less VATS single port thymectomy, while 66 underwent thymectomy through open sternotomy. Many clinical factors associated with the surgical and clinical outcomes, including tumor recurrence and clinical remission, were recorded.

RESULTS

Non major postoperative complications were observed in any group. The median operative time and postoperative hospital stay of CO₂-less VATS single port thymectomy were 95 min and 1 day, respectively and 120 min and 7 days for open sternotomy. The thymoma was the most common thymic disorder with 7 patients (38%) in VATS group and 28 patients (42.4%) for the open approach. The median lesion size was 2.6 cm in the VATS group and 3.2 cm in the open approach. No thymoma recurrence in patients undergoing VATS was observed during the follow-up time, while in the open surgery group 14.28% recurrence was observed, distributed as follows: loco-regional 75% and 25% at distance; free disease period of these patients was 8.3 months. Thymectomy associated with myasthenia gravis (MG) was observed in 6 (33%) patients in the VATS group and 32 (48%) patients for sternotomy; our results regarding thymectomy for the treatment of MG were established by the MG post-intervention status [complete stable remission (CSR), pharmacologic remission, minimal manifestations, improved, unchanged and worse exacerbation, and died of MG] and reflected similar results in both approaches.

CONCLUSIONS

CO₂-less VATS single-port thymectomy is a feasible and safe procedure. Oncologic outcomes are similar to open approaches. Complications, surgical time and hospital stay are shorter compared with sternotomy. This is an initial experience, further work is required to evaluate long-term results.

Impact of artificial capnothorax on coagulation in patients during video-assisted thoracoscopic esophagectomy for squamous cell carcinoma

BACKGROUND

Compared with the lung isolation using double-lumen endobronchial tube intubation, the artificial capnothorax using single-lumen endotracheal tube intubation has shown to be a safe, more convenient, and cost-effective procedure for thoracoscopic esophagectomy. However, the impact of capnothorax on coagulation is not well defined. Herein, we evaluate the impact of a capnothorax on coagulation and fibrinolysis in patients who undergoing thoracoscopic esophagectomy.

METHODS

Between March 2014 and August 2014, 24 patients underwent thoracoscopic esophagectomies for esophageal cancer with the procedure of artificial capnothorax (group P); we also performed 24 thoracoscopic esophagectomy cases without using capnothorax (group N). The demographics and arterial blood gas, as well as the parameters of coagulation and fibrinolysis, of the two groups were analyzed.

RESULTS

The pH value of group P after CO2 insufflation was significantly lower than in group N (P < 0.05), and the partial pressure of carbon dioxide (PaCO2) was significantly increased compared with group N (P < 0.05). The R and K values after CO2 insufflation were significantly longer than before anesthesia (P < 0.05), and both α angle and MA value after CO2 insufflation were significantly lower than those before anesthesia (P < 0.05). No significant differences in R value, K value, α angle, or MA value were observed between pre-anesthesia and termination of capnothorax. No significant difference in LY30 data was found between different groups (P > 0.05).

CONCLUSION

Artificial capnothorax in patients receiving endoscopic resection of esophageal carcinoma had a significant impact on coagulation. These patients showed significant impairments in coagulation not observed in patients without artificial capnothorax.

Anesthetic issues for robotic cardiac surgery

As innovative technology continues to be developed and is implemented into the realm of cardiac surgery, surgical teams, cardiothoracic anesthesiologists, and health centers are constantly looking for methods to improve patient outcomes and satisfaction. One of the more recent developments in cardiac surgical practice is minimally invasive robotic surgery. Its use has been documented in numerous publications, and its use has proliferated significantly over the past 15 years. The anesthesiology team must continue to develop and perfect special techniques to manage these patients perioperatively including lung isolation techniques and transesophageal echocardiography (TEE). This review article of recent scientific data and personal experience serves to explain some of the challenges, which the anesthetic team must manage, including patient and procedural factors, complications from one-lung ventilation (OLV) including hypoxia and hypercapnia, capnothorax, percutaneous cannulation for cardiopulmonary bypass, TEE guidance, as well as methods of intraoperative monitoring and analgesia. As existing minimally invasive techniques are perfected, and newer innovations are demonstrated, it is imperative that the cardiothoracic anesthesiologist must improve and maintain skills to guide these patients safely through the robotic procedure.

[Thoracoscopic thymectomy with carbon dioxide insufflation in the mediastinum]

The case is presented of a 71 year-old male, diagnosed with a thymoma. A thoracoscopic thymectomy was performed using the carbon dioxide insufflation technique in the mediastinum. During the procedure, while performing one-lung ventilation, the patient's respiration worsened. The contralateral lung had collapsed, as carbon dioxide was travelling from the mediastinum to the thorax through the opened pleura. Two-lung ventilation was decided upon, which clearly improved oxygenation in the arterial gases and airway pressures. Both pH and pCO2 stabilized. The surgical approach and the carbon dioxide technique were continued because 2-lung ventilation did not affect the surgical procedure. This technique has many serious complications and it should always be performed using 2-lung ventilation.

Anesthetic management of the patient with dilated cardiomyopathy undergoing pulmonary resection surgery: a case-based discussion

Interactions between the cardiovascular and respiratory systems are complex and profound. General anesthesia, muscle relaxation, and positive-pressure ventilation all impose physiological effects on cardiovascular function. In patients presenting for pulmonary resection, additional effects resulting from positioning, 1-lung ventilation, surgical procedures, and contraction of the pulmonary vascular bed may impose an additional physiological burden. For most patients with adequate pulmonary and cardiovascular reserve, these effects are well tolerated. However, the cardiothoracic anesthesiologist may be asked to provide anesthetic care for patients with significantly reduced cardiac function who require potentially curative pulmonary resection for lung cancer. These patients present a major perioperative challenge and a thoughtful approach to intraoperative management is required. The authors review a case of a patient with severely impaired biventricular function who presented for elective pulmonary lobectomy in an attempt to effect a curative resection of lung cancer and present a discussion of physiological and pathophysiological considerations for clinical management.

Hybrid coronary revascularization: a review

The long-term benefits of a left internal mammary artery bypass graft compared to the left anterior descending artery have been well described. The use of drug-eluting stents has minimized the morbidity of revascularization. Hybrid coronary revascularization is the planned use of minimally invasive surgical techniques for left internal mammary artery-left anterior descending artery grafting and the use of percutaneous coronary intervention for nonleft anterior descending coronary artery target revascularization. The optimal timing and order of revascularization in hybrid coronary revascularization remains unclear.

Asystole following positive pressure insufflation of right pleural cavity: a case report

INTRODUCTION

Adverse hemodynamic effects with severe bradycardia have been previously reported during positive pressure insufflation of the right thoracic cavity in humans. To the best of our knowledge, this is the first report of asystole during thoracoscopic surgery with positive pressure insufflation.

CASE PRESENTATION

A 63-year-old Caucasian woman developed asystole at the onset of positive pressure insufflation of her right hemithorax during a thoracoscopic single-lung ventilation procedure. Immediate deflation of pleural cavity, intravenous glycopyrrolate and atropine administration returned her heart rhythm to normal sinus rhythm. The surgery proceeded in the absence of positive pressure insufflation without any further complications.

CONCLUSIONS

We discuss the proposed mechanisms of hemodynamic instability with positive pressure thoracic insufflation, and anesthetic and insufflation techniques that decrease the likelihood of adverse hemodynamic events.

Robotically assisted atraumatic coronary artery bypass: a feasible option for off-pump coronary surgery

This retrospective study of the largest single center experience (100 patients) with off-pump robotically assisted coronary procedures in the United Kingdom (April 2002-June 2008) aimed to rationalize patient selection, describe the technique, and determine the learning curve, technical feasibility and operative outcome of robotically assisted Atraumatic Coronary Artery Bypass (ACAB). Selected patients underwent either a robotic Totally Endoscopic Coronary Artery Bypass (12) or robotically assisted ACAB (88) using a standard Da Vinci robot with three arms. A fifth of all cases had percutaneous interventions as part of a hybrid strategy. The majority of patients were overweight men. After one hundred robotic coronary procedures, this operation is now performed as part of a routine theatre list. The mean operative and total procedure times for robotically assisted atraumatic procedures were 157 and 238 min, respectively. These measurements were significantly less in the atraumatic than the totally endoscopic group with a 34.3 and 20.6% reduction, respectively (P < 0.001; equal variance not assumed). The procedural learning curve was short and independent from internal thoracic artery harvesting. We have proven conclusively that robotically assisted ACAB is feasible, more so than the totally endoscopic procedure in this particular setting. Even in the absence of an ideal stabilizer device, this procedure causes minimal disruption to the daily operating room schedule. We have also proven that body mass index is a weak predictor of the ease of robotic internal thoracic artery harvesting and should not affect patient selection.

Current state of integrated "hybrid" coronary revascularization

The long-term benefits of a left internal mammary artery bypass graft to the left anterior descending artery (LAD) have been well described. As the patient population with multivessel coronary artery disease has grown older with greater comorbidities, less invasive approaches to revascularization have been explored. The use of drug-eluting stents has minimized the morbidity of revascularization but has failed to match the durability of coronary artery bypass grafting (CABG). Hybrid coronary revascularization (HCR) is the planned use of minimally invasive surgical techniques for left internal mammary artery-LAD grafting and the use of percutaneous coronary interventions (PCI) for non-LAD target revascularization. The optimal timing and order of revascularization in HCR remains unclear. Novel operating suites with surgical and fluoroscopic capabilities have begun to support the performance of simultaneous minimally invasive CABG and PCI. The role of HCR compared to both PCI and conventional CABG awaits the results of ongoing randomized clinical trials.

[Coronary artery bypass grafting in conscious patients: a procedure with a perspective?]

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.

Segmental myocardial wall motion during minimally invasive coronary artery bypass grafting using open and endoscopic surgical techniques

Current options for minimally invasive surgical treatment of single-vessel coronary artery disease include beating heart procedures without cardiopulmonary bypass (CPB) via mini-thoracotomy (MIDCAB) and totally endoscopic robot-assisted techniques (TECAB) with CPB. Both procedures are associated with potential myocardial stress before revascularization, such as single-lung ventilation (SLV), temporary coronary artery occlusion, cardiac luxation, intrathoracic carbon dioxide insufflation, and extended CPB and operating time. In this echocardiographic study we sought to evaluate the extent of intraoperative segmental wall motion abnormalities (SWMA) during MIDCAB and TECAB surgery and to identify factors affecting SWMA. Forty-six patients with single-vessel coronary artery disease were studied. Sixteen patients were operated using the MIDCAB technique and 30 patients with TECAB. In both groups sequential transesophageal echocardiograms were recorded during the entire procedure. Hemodynamic data and oxygenation variables were acquired simultaneously. In both groups, mild but obvious perioperative SWMA were identified and noted to increase during the course of the operation. These SWMA were more pronounced in the TECAB group. Independent of operating time, these changes disappeared completely after revascularization. No significant hemodynamic compromise was observed. We conclude that MIDCAB and TECAB techniques are associated with significant perioperative SWMA. The appearance of more profound SWMA in the TECAB group compared with the MIDCAB patients might have been the result of intrathoracic CO(2) insufflation, as SLV was used in both groups. No persistent SWMA or post-CPB SWMA were apparent in either group. More extensive intraoperative ventricular SWMA was detected in the TECAB group, suggesting that a more frequent risk for right ventricular dysfunction may exist during TECAB procedures.

Current status of robotically assisted coronary revascularization

This article reviews the current status of totally endoscopic coronary revascularization using telemanipulation systems for robotic assistance. Current challenges in implementing a robotic surgical program are discussed, and application of the technology in both arrested and beating heart procedures is considered.

Totally endoscopic coronary artery bypass grafting on cardiopulmonary bypass with robotically enhanced telemanipulation: report of forty-five cases

BACKGROUND

Robotically enhanced telemanipulation is a new powerful tool for minimally invasive procedures that allows totally endoscopic cardiac surgery. Between June 1999 and February 2001, 45 robotically enhanced totally endoscopic coronary artery bypass grafting procedures on the arrested heart were performed at our institution with the use of the da Vinci telemanipulation system (Intuitive Surgical, Inc, Mountain View, Calif).

METHODS

In 37 patients a single-vessel totally endoscopic coronary bypass operation was performed. Eight patients had different types of multivessel revascularization with both internal thoracic arteries. The initial conversion rate was 22% and dropped to 5% in the last 20 patients. Two patients required reexploration via median sternotomy. The first 22 patients had excellent graft patency on discharge. The procedural time for single-vessel totally endoscopic bypass was 4.2 +/- 0.4 hours, bypass time was 136 +/- 11 minutes, and aortic crossclamp time amounted to 61 +/- 5 minutes.

CONCLUSION

The present data show the feasibility of closed chest single- and double-vessel revascularization, with good clinical results. However, procedural time is prolonged and the complex endoscopic and endoaortic occlusion techniques, as well as the extensive anesthesiologic monitoring, are demanding. The need for conversion to an open procedure diminished after a relatively short learning curve. All postulated benefits of totally endoscopic surgery other than excellent cosmesis must be evaluated in larger cohorts.