Intraoperative Ventricular Fibrillation Research Articles

Blood cardioplegia reduces intraoperative ventricular fibrillation and transfusion requirements compared to crystalloid cardioplegia in canine mitral valve repair.

Cardioplegic solutions are indispensable for open-heart surgeries, including mitral valve repair (MVR), a potentially curative treatment for myxomatous mitral valve disease in dogs. However, procedural methodologies are not fully established, and complications are yet to be comprehensively understood. Cardioplegic solutions contain various substances to protect the myocardium under temporal cardiac arrest. Nevertheless, ventricular fibrillation (VF) occurs as a common complication after releasing the crossclamp. Based on these backgrounds, the search for optimal cardioplegic solutions in dogs undergoing MVR is an urgent issue. This study aims to evaluate the occurrence of VF in dogs treated with blood cardioplegia (BCP) versus crystalloid cardioplegia (CCP) during MVR. A total of 251 client-owned dogs who underwent MVR from November 2015 to November 2017 were included. We retrospectively assessed the relationship between VF and type of cardioplegia (CCP or BCP) based on surgical records, including VF incidence, transfusion use, crossclamp time, and echocardiographic measurements. Logistic regression analysis showed that the CCP group was associated with the occurrence of VF (OR, 2.378; CI, 1.133-4.992; P = .022). In addition, the CCP group was associated with transfusion use (OR, 2.586; CI, 1.232-5.428, P = .022). There was no difference between the groups for the pre- and postoperative echocardiographic measurements. The BCP group had a lower incidence of VF and less transfusion use than the CCP group. This finding indicates that BCP may be a superior cardioplegic technique for MVR in dogs.

Machine learning model-based risk prediction of severe complications after off-pump coronary artery bypass grafting.

Compared with coronary artery bypass grafting (CABG) under cardiopulmonary bypass, off-pump coronary artery bypass (OPCAB) is minimally invasive and reduces the risk of intraoperative blood transfusion and acute kidney injury. Nonetheless, OPCAB-related complications still pose a threat. Machine learning technology can analyze a large number of clinical data, establish risk prediction models and help clinicians make early and correct clinical decisions. Risk prediction models are available for mortality and morbidity after cardiac surgery, but they are not specific to OPCAB. This study aimed to develop a predictive model of severe complications after OPCAB, based on machine learning. Anesthesia records of OPCAB from the General Hospital of the Northern Theater Command (Shenyang, China) collected between January 1, 2019, and June 15, 2020, were analyzed. The endpoint of the study was the occurrence of serious complications after OPCAB (postoperative unplanned intra-aortic balloon pump, secondary surgery and death). The features entered into the models were as follows: intraoperative ventricular fibrillation, number of saphenous vein grafts, nerve block (NeB), venous oxygen saturation (SvO2), skin incision-bypass time, and hypertension. A total of 8 machine learning algorithms were tested: logistic regression analysis (LRA), k-nearest neighbor (KNN), naïve Bayes (NB), support vector machine (SVM), random forest (RF), extreme gradient boosting (XGBoost), light gradient boosting machine (LightGBM), and categorical features gradient boosting (CatBoost). Among the 506 patients found in the records, 27 met the endpoint. The highest area under the curve (AUC) value was achieved with the XGBoost model (AUC = 0.94), and the lowest with the SVM model (AUC = 0.75). The highest and lowest accuracy were observed with the XGBoost and NB models, respectively, while the highest and lowest precision were achieved using the SVM and NB models, respectively. Based on the receiver operating characteristic (ROC) curves, the XGBoost model was selected as the most useful in this study. This study suggests using the XGBoost model to predict the risk of complications after OPCAB.

Ventricular fibrillation during carotid endarterectomy and bailout stenting: a case report

BackgroundCarotid artery manipulation is not a special technique but reports of intraoperative ventricular fibrillation are rare. The risk of fatal arrhythmias may be hidden behind routine surgical techniques and anesthetic management. We focused on QT prolongation and QT dispersion.Case presentationA 77-year-old man underwent carotid endarterectomy and bailout stenting. Although there were no obvious preoperative risk factors for intraoperative ventricular tachyarrhythmia, ventricular fibrillation (VF) had occurred during a maneuver of the carotid artery under hypercapnia. QTc was prolonged from 317 ms before surgery to 458 ms before the onset of VF. QTc dispersion between leads II and III was also increased to 50 ms. Hypomagnesemia was noted after resuscitation by electrical defibrillation, adrenaline, and noradrenaline.ConclusionsWe considered that the combination of multiple risk factors led to the development of ventricular fibrillation. It should be noted that carotid artery manipulation has the potential to cause arrhythmias.

Effects of ischaemic postconditioning in aortic valve replacement: a multicenter randomized controlled trial.

The effect of ischaemic postconditioning (IPost) on postcardioplegic cardiac function is not known. We hypothesized that IPost was cardioprotective in adult patients undergoing elective aortic valve replacement. In a multicentre, prospective, randomized trial, patients (n = 209) were randomized to either a standard operation (controls) or postconditioning. Immediately before the cross-clamp was released, patients in the postconditioning group underwent 3 cycles of flow/non-flow (2 min each) of normothermic blood via the antegrade cardioplegia line. The primary end point was cardiac index. Secondary end points included additional haemodynamic measurements, biomarkers of cardiomyocyte injury, renal function parameters, intra- and postoperative arrhythmias and use of inotropic agents. There was no significant difference between the groups regarding cardiac index [mean between-group difference, 95% confidence interval (CI), 0.11 (-0.1 to 0.3), P = 0.27]. Postconditioning had no effect on other haemodynamic parametres. There was no between-group difference regarding troponin T or creatine kinase MB. Postconditioning reduced the relative risk for arrhythmias by 45% (P = 0.03) when postoperative atrial fibrillation and intraoperative ventricular fibrillation were combined. There were no differences in patients with/without diabetes, patients above/below 70 years of age or between the centres. However, after postconditioning, the cardiac index [95% CI, 0.46 (0.2-0.7), P = 0.001], cardiac output (P < 0.001), mean arterial pressure (P < 0.001) and left ventricular stroke work index (P < 0.001) were higher in males compared to females. IPost had no overall cardioprotective effects in patients undergoing aortic valve replacement but improved postoperative cardiac performance in men compared to women.

Effects of off-pump coronary artery bypass graft on the clinical efficacy, surgical indicators, and cardiac function of patients with coronary heart disease.

Coronary heart disease (CHD) is a common clinical cardiovascular disease. This study aimed to analyze the effects of off-pump coronary artery bypass graft on the clinical efficacy, surgical indicators, and cardiac function of patients with CHD. We retrospectively analyzed the clinical data of 120 patients with CHD who were treated in our hospital from May 2017 to May 2020. And they were divided into the control group (extracorporeal coronary artery bypass graft) and the observation group (off-pump coronary artery bypass graft). The clinical efficacy, surgical indicators, cardiac function, myocardial injury, the degree of cardiac autonomic nerve imbalance, incidence of complications and quality of life one year after the operation in the 2 groups were compared. The total effective rate of the observation group was significantly higher than that of the control group. Intraoperative blood loss, operation time, intraoperative blood transfusion, and hospital stay in the observation group were significantly better than those in the control group. After treatment, the levels of cardiac index (CI), ejection fraction (EF), stroke volume (SV), and cardiac output (CO) in the observation group and the control group were higher than those before treatment, especially in the observation group. Compared with those before operation, CK-MB and cTnI of the two groups significantly increased at all time points after surgery. After treatment, SDNN, LF, HF, and TP of patients in the two groups increased, which was significant in the observation group. The incidence of complications such as myocardial infarction, ischemic changes, respiratory insufficiency, and intraoperative ventricular fibrillation in the observation group was significantly lower than that in the control group. The score of quality of life in the observation group was significantly higher than the control group. In the treatment of patients with CHD, off-pump coronary artery bypass graft has good clinical effects, which can significantly improve the heart function, and cardiac autonomic nerve imbalance of patients, reduce myocardial damage, decrease the incidence of complications, and improve the quality of life. Therefore, off-pump coronary artery bypass graft is worthy of clinical application.

Transcatheter mitral valve implantation using a novel system: preclinical results.

BackgroundThis preclinical study in sheep sought to demonstrate the initial safety and feasibility of a novel transcatheter mitral valve system (Mi-thos valve) composed of a self-expanding frame and a bovine pericardial tissue bioprosthesis.MethodsThe valve was implanted in 26 sheep using a transapical approach for short- and long-term evaluation. The technical feasibility, safety, durability, and valve function were evaluated during and 6 months after the procedure using intracardiac and transthoracic echocardiography, multisliced computed tomography, histological analysis, and electron microscopy.ResultsThe success rate of valve implantation was 100%, and the immediate survival rate after surgery was 84%. Five animals died within 90 min after the development of the prosthetic valve due to an acute left ventricular outflow tract obstruction (n = 2) and sudden intraoperative ventricular fibrillation (n = 3). Twelve animals died within 1 month due to acute left heart dysfunction. Mild (n = 5) and moderate (n = 2) paravalvular leakage occurred in seven animals, and two moderate PVL animals died of chronic heart failure within three months. Multimodality imaging studies of the remaining seven animals showed excellent function and alignment of the valves, with no coronary artery obstruction, no left ventricular outflow tract obstruction, no severe transvalvular gradients and no paravalvular leakage. Macroscopic evaluation demonstrated stable, secure positioning of the valve, with full endothelialization of the valve leaflets without injury to the ventricular or atrial walls. Histological and electron microscopic examinations at six months showed no obvious macro- or microcalcification in the leaflets.ConclusionsPreclinical studies indicate that transcatheter implantation of the Mi-thos valve is technically safe and feasible. The durability, functionality, and lack of leaflet calcification were all verified in animal experiments. The information from these preclinical studies will be applied to patient selection criteria and the first-in-human studies.

Efficacy of radiofrequency catheter ablation for premature ventricular contractions in children.

This study evaluated the efficacy and safety of transcatheter radiofrequency ablation (RFCA) in treating ventricular premature contractions (PVCs) in children, summarized the countermeasures during intraoperative ventricular fibrillation (VF), and improved the safety of ventricular premature treatment. A retrospective analysis was conducted on 75 children with PVCs who received RFCA in the Second Affiliated Hospital of Wenzhou Medical University from January 2010 to April 2019. Data including age, sex, body weight, ejection fraction, left ventricular end diastolic diameter, burden and number of PVCs/24h, origin of PVCs, and its complications were collected. Paired t test was used to compare changes in cardiac function before and after surgery. Among the 75 cases treated with RFCA, 68 were successfully ablated, giving a success rate of 90.67%. After ablation, the left ventricular ejection fraction (LVEF) of the children was 69.13 ± 3.81%, which was significantly higher than that before surgery (69.13 ± 3.81% vs. 66.21 ± 3.22%, P= 0.012). One of the patients experienced VF during the operation, with no other complications. The initial locus of origin was the anterior septum of the right ventricular outflow tract, but VF occurred during the ablation process. Mean follow-up time was 39 ± 33 months, with two recurrent cases (2.94%). Performing RFCA in children is safe and effective, with a low recurrence rate and few complications. VF is not an indication to cease surgery; the key to eliminating complications is repositioning the catheter and finding a more accurate origin point.

Ranolazine in Preventing Ventricular Fibrillation During Aortic Valve Replacement in Patients with Low Ejection Fraction: A Single-Centre Retrospective Study

Objectives: Aortic valve replacement (AVR) is often associated with intraoperative ventricular fibrillation (VF) complicating early postoperative outcomes. Ca2+ triggering mechanisms induced by ischemia-reperfusion injury have been implicated as possible causes of this arrhythmia, however, the exact mechanisms remain unclear. The aim of this study was to investigate the role of late sodium current inhibition by ranolazine (RAN) in preventing VF in these patients.

Successful Two-Stage Operation for Perforation of Gastric Ulcer into the Left Ventricle Accompanied by Intraoperative Ventricular Fibrillation

Successful Two-Stage Operation for Perforation of Gastric Ulcer into the Left Ventricle Accompanied by Intraoperative Ventricular Fibrillation

Intraoperative ventricular fibrillation arrest caused by accidental intravenous injection of epinephrine

We describe a 25-year old male who experienced ventricular fibrillation (V-Fib) arrest induced by inadvertent intravenous injection of epinephrine instead of the routine reversal medication. Under general anesthesia with Desflurane inhalation, 1.5% Lidocaine containing 1:100,000 Epinephrine was injected into the nasal mucosa for septoplasty and the procedure went smoothly. Near the end of the surgery, the patient suddenly developed sinus tachycardia followed by V-Fib arrest which responded to a single shock of 300J. Sinus rhythm was restored immediately. The patient developed severe lactic acidosis and a bedside echocardiography showed global hypokinesia and normal right sided pressures. The patient was intubated and admitted to the ICU on mechanical ventilation before being weaned and extubated. Retrospectively while investigating the cause after it was discovered that epinephrine had been given as opposed to the anesthesia reversal medication. This case illustrates an unusual response to epinephrine with cardiac arrest in a healthy young male.

Shock or no shock - a question of philosophy or should intraoperative implantable cardioverter defibrillator testing be recommended?

Implantation of implantable cardioverter defibrillators (ICDs) in patients with a high risk for life-threatening ventricular arrhythmias is a standard therapy. The development of new ICD leads, shock algorithms, high-energy defibrillators and rapid energy supply has improved the devices. Nevertheless, the discussion regarding 'shock or no shock' to test the system intraoperatively has not silenced yet. In this study, all 718 patients (60.0 ± 14.2 years old, 570 male) who were treated with a first ICD at our institution since 2005 were analysed. The indication for implantation was primarily prophylactic in 511 patients (71.3%). Underlying diseases included ischaemic cardiomyopathy (358 patients, 50%), dilated cardiomyopathy (270 patients, 37.7%) and others (12.3%). Mean ejection fraction was 27.4 ± 11.8%. Intraoperative ventricular fibrillation was induced with a T-wave shock or burst stimulation. The primary end-point was failing the initial intraoperative testing. During the initial testing, 28 patients (3.9%) had a defibrillation threshold (DFT) >21 J. The mean age of these patients was 51 ± 14 years, ranging from 22 to 71 years, 20 were male, and the ejection fraction was 23.8 ± 11.8%. The indication for ICD implantation was prophylactic in 13 patients. Twenty-one of the 28 patients suffered from dilated cardiomyopathy, whereas seven patients had ischaemic cardiomyopathy. Twenty-four ICDs were implanted on the left side and four on the right side. None of the patients had been treated with amiodarone at the time of implantation. All patients achieved a sufficient DFT ≤ 21 J by changing the ICD leads, device repositioning and/or optimizing the shock configuration. The standard of care intraoperative ICD testing remains necessary.

Studying semblances of a true killer: experimental model of human ventricular fibrillation

It is unknown whether ventricular fibrillation (VF) studied in experimental models represents in vivo human VF. First, we examined closed chest in vivo VF induced at defibrillation threshold testing (DFT) in four patients with ischemic cardiomyopathy pretransplantation. We examined VF in these same four hearts in an ex vivo human Langendorff posttransplantation. VF from DFT was compared with VF from the electrodes from a similar region in the right ventricular endocardium in the Langendorff using two parameters: the scale distribution width (extracted from continuous wavelet transform) and VF mean cycle length (CL). In a second substudy group where multielectrode phase mapping could be performed, we examined early VF intraoperatively (in vivo open chest condition) in three patients with left ventricular cardiomyopathy. We investigated early VF in the hearts of three patients in an ex vivo Langendorff and compared findings with intraoperative VF using two metrics: dominant frequency (DF) assessed by the Welch periodogram and the number of phase singularities (lasting >480 ms). Wavelet analysis (P = 0.9) and VF CL were similar between the Langendorff and the DFT groups (225 ± 13, 218 ± 24 ms; P = 0.9), indicating that wave characteristics and activation rate of VF was comparable between the two models. Intraoperative DF was slower but comparable with the Langendorff DF over the endocardium (4.6 ± 0.1, 5.0 ± 0.4 Hz; P = 0.9) and the epicardium (4.5 ± 0.2, 5.2 ± 0.4 Hz; P = 0.9). Endocardial phase singularity number (9.6 ± 5, 12.1 ± 1; P = 0.6) was lesser in number but comparable between in vivo and ex vivo VF. VF dynamics in the limited experimental human studies approximates human in vivo VF.

A case of intra-operative ventricular fibrillation: Electro-cauterization, undiagnosed Takotsubo cardiomyopathy or long QT syndrome?

IntroductionCardiac arrest in the perioperative setting is an extremely serious event that is estimated to occur between 4.6 and 19.7 per 10,000 anesthetics.1–5 While risk factors for cardiac complications can be identified pre- operatively, in many cases workup of risk factors are not indicated by standard pre-operative testing guidelines. Presentation of caseWe present a case of a 47-year-old female undergoing an elective bilateral mastectomy who suddenly converted to ventricular fibrillation. While ventricular fibrillation is not a unique finding, our search for its etiology revealed two previously undiagnosed cardiac conditions, and possible electro- cautery induced ventricular fibrillation. DiscussionIn this case study, we discuss the possible etiology of ventricular fibrillation in our patient and highlight the importance pre-operative patient investigation and history provide. ConclusionSearching for the potential causes that may have contributed to the cardiac arrest is an extremely useful exercise as it allows us to better prepare patients pre-operatively, improve intra-operative care, and prevent future cardiac events.

A Case of Inefficient Defibrillation During Thoracotomy

We describe the case of an accidental intraoperative ventricular fibrillation that could not be interrupted by a 35-J shock fired by an implantable cardioverter defibrillator (ICD). We believe that the iatrogenic pneumothorax induced by thoracotomy during the epicardial lead implant temporarily changed the intrathoracic impedance, causing an increase in defibrillation threshold. This possible change in impedance with resulting ineffective interruption of arrhythmia should be taken in consideration when a thoracotomy is planned in a patient bearing an ICD.

A Report of the Vancouver Forum on the Care of the Live Organ Donor: Lung, Liver, Pancreas, and Intestine Data and Medical Guidelines

An international conference of transplant physicians, surgeons, and allied health professionals was held in Vancouver, Canada, on September 15 and 16, 2005 to address the care of the live lung, liver, pancreas, and intestine organ donor. The Vancouver Forum was convened under the auspices of the Ethics Committee of The Transplantation Society. Forum participants included over 100 leaders in organ transplantation, representing many countries from around the world, including participants from the following continents: Africa, Asia, Australia, Europe, North and South America. The objective of the Vancouver Forum was to develop an international standard of care for the live lung, liver, pancreas and intestinal organ donor. This Vancouver Forum followed a conference convened in Amsterdam on the care of the live kidney donor (1, 2). There were four organ specific work groups at the Vancouver Forum: lung, liver, pancreas and intestine. Each organ work group addressed the following topics in concert and reported their findings in a plenary presentation to all participants:

Complications of Reperfusion in Acute Aortic Artery Occlusion Following Saddle Embolization Originating from an Atrial Myxoma

A 58-year-old man presented to the hospital with an 8-hour history of acute-onset bilateral lower limb ischemia. A large saddle embolus had occluded the aorta and could not be removed by balloon endarterectomy through the femoral arteries. Successful open aortic and femoral thromboembolectomy followed by extensive fasciotomies was accompanied by severe reperfusion injury. Life-threatening hyperkalemia was associated with three episodes of intraoperative ventricular fibrillation and ventricular tachycardia requiring cardiac massage and defibrillation. A dextrose-insulin-bicarbonate infusion was required to correct the hyperkalemia. Rhabdomyolysis developed at 24 hours, causing marked myoglobinuria and acute renal failure, which required hemofiltration. Histology of the recovered embolus confirmed an atrial myxoma, and when the patient had fully recovered, open cardiac surgery was carried out to resect the tiny stump of residual myxoma. Rhabdomyolysis associated with a myxomatous saddle embolus has not been previously reported. This case highlights the need for pre- and perioperative measures to be taken to overcome hyperkalemia and acute renal failure when revascularizing acute, massive, prolonged ischemia of the lower body.

Transmyocardial laser revascularization: epicardial ECG detection provides efficient R-wave triggering during mobilization of the heart.

In order to achieve an accurate intraoperative ECG detection, a new technique in detecting the trigger-signal was developed. In contrast to the traditional three-lead ECG-configuration, the left leg electrode was connected to a transient epicardial pacemaker electrode on the left-ventricular surface. The Holmium:YAG-Laser for Transmyocardial Laser Revascularization (TMLR) is R-wave-triggered, providing the release of energy only during the refractory period of the heart cycle. However, an exact ECG-triggering during mobilization of the apex and/or posterior wall is difficult to achieve by using conventional ECG-configuration, therefore increasing the risk for mistriggering and induction of arrhythmias during TMLR. Two groups of patients, all undergoing stand alone TMLR-procedures via left minithoracotomy, were compared. Ten patients were operated with the conventional ECG configuration (group 1) and ten patients with the modified epicardial ECG configuration (group 2). In patients of group 1, as a result of a loss of the trigger signal or due to the triggering of artifacts, the incidence of correctly triggered QRS-complexes was 56% of all documented QRS-complexes. In contrast, an excellent triggering was observed in 98% (p < 0.001) in group 2, resulting in a reduction of laser operative time by 35% (p < 0.001) and a decrease in the incidence of intraoperative ventricular fibrillation (0 vs. 3). In conclusion, this new ECG configuration is a simple but effective method in achieving an excellent ECG signal during all stages of TMLR. As a consequence, a reduction in operative time and incidence of ventricular fibrillation can be achieved.

Differences in brain oxygenation between two sequential cardiac arrests during axillobifemoral bypass in a stanford type A dissecting aneurysm

ISCHEMIC PRECONDITIONING is a protective mechanism against long-lasting ischemic events after a short period of ischemia in many organ systems. 1,2 There has been only one study addressing this phenomenon in the nervous system in humans. 3 Several mechanisms of ischemic preconditioning, such as adenosine triphosphate (ATP)—sensitive potassium channel (K ATP), reactive oxygen species, and protein kinase C, have been proposed, 1 and an animal study revealed that mild cerebral ischemic stress can induce improvement in brain oxygen metabolism detected by near-infrared spectroscopy (NIR) during subsequent ischemia. 4 Although there have been several reports using NIR to monitor cerebral oxygenation during cardiac arrest, only hemoglobin saturation was measured. 5,6 The dynamic changes of saturation can be useful, and the changes of this value correlated well with brain hypoxia within individuals. 7 The readings obtained from the instrument need to be carefully interpreted in clinical medicine, however. 7–9 Monitoring of hemoglobin saturation alone may not be adequate for the assessment of cerebral oxygenation because during hypothermic cardiopulmonary bypass, a decreased in tissue oxygenation occurred despite an increase in cerebral oxyhemoglobin (HbO 2) concentration. 10 There are two types of commercially available NIR instruments that can measure brain oxygenation: tissue saturation instruments, as previously mentioned, and concentration-measuring instruments. Concentration-measuring instruments show the changes of HbO 2, deoxyhemoglobin (Hb), sum of HbO 2 and Hb (total Hb), and cytochrome aa 3 (Cytaa 3). 11 During brain ischemia, the concentration-measuring instrument shows a decrease of HbO 2 accompanied by an increase of Hb. 11,12 In addition to the changes of HbO 2 and Hb, it has been reported that the changes in total Hb are useful indicators of alterations in cerebral blood volume and that the alterations in total Hb are linearly related to those in cerebral blood flow, 13,14 if the concentration of hemoglobin in blood is not changed. A report also indicated that a significant correlation between changes in cerebral blood flow and changes in total Hb was found in human subjects using NIR and positron-emission tomography. 15 Cytaa 3 is the terminal enzyme of the mitochondrial electron transport chain, the site of electron transfer to molecular oxygen. It has been shown that decreases in phosphocreatine and nucleotide triphosphate (mostly ATP) measured by magnetic resonance spectroscopy correlated closely with decreased Cyaa 3 detected by NIR and arterial blood pressure in piglets. 12 Monitoring the oxidative status of Cytaa 3 may provide a true look at the status of tissue oxygenation inside the neuronal cells, 16 if the chromophore path length is not changed. The authors report intraoperative brain oxygenation detected by NIR during an axillobifemoral bypass in a patient with a Stanford type A dissecting aneurysm who experienced two episodes of intraoperative ventricular fibrillation (VF).

What Is ‘Minimally Invasive’ Coronary Bypass Surgery?: Experience With a Variety of Surgical Revascularization Procedures for Single-Vessel Disease

Although the use of small incisions is theoretically appealing, it has been argued that the true advantage of minimally invasive approaches to myocardial revascularization lies in the avoidance of cardiopulmonary bypass. Of 25 patients referred for surgical revascularization of single-vessel coronary disease, 20 elected to undergo a minimally invasive coronary artery bypass grafting (MICABG) procedure, while 5 opted to have conventional surgery with cardiopulmonary bypass (CPB). Patients having MICABG underwent single-vessel revascularization without CPB, via limited anterior thoracotomy, hemisternotomy, or median sternotomy. Intraoperatively, hemodynamics, anastomotic time, and total operative time were recorded. Postoperatively, length of hospital stay, incidence of myocardial infarction, indexes of end-organ function, and morbidity rates were recorded. In addition, patient questionnaires were used to assess subjective end points such as postoperative pain, wound drainage, and quality of life. Fifteen of 20 patients undergoing MICABG underwent revascularization without CPB, while 4 were converted to standard coronary artery bypass grafting with CPB due to technical reasons and 1 for intraoperative ventricular fibrillation. Patients undergoing MICABG had no perioperative myocardial infarctions, while those having CPB had two infarctions (20%). Furthermore, there were no differences in length of stay or postoperative morbidity among the various approaches, while the MICABG procedures, especially via median sternotomy, were associated with shorter operative times. The advantage of MICABG lies mainly in the avoidance of CPB. Thus, we advocate that surgeons initially utilize the median sternotomy and limited skin incision for MICABG to assure adequate exposure, technical precision, and patient safety. After a reasonable level of technical proficiency and experience are attained, the limited anterior thoracotomy approach can be used.

Off-bypass coronary bypass grafting via minithoracotomy using mechanical epicardial stabilization

Minimally or less invasive surgical coronary revascularization has gained increasing interest along with new techniques and devices designed for easier and safer procedures. Until recently, it appeared questionable whether grafting techniques with avoidance of cardiopulmonary bypass techniques would allow adequate results compared with conventional techniques using cardioplegic arrest. Since June 1996, minimally invasive direct coronary artery bypass grafting procedures without cardiopulmonary bypass were intended in 24 patients (19 male, 5 female; age, 60.5 +/- 10.5 years) applying a special system (CardioThoracic Systems, Inc) for internal mammary artery access and epicardial surface stabilization approaching through an anterolateral minithoracotomy. Neither video-assisted preparation nor additional pharmacologic stabilization was applied. Concomitant risk factors and associated comorbidity were frequent. The procedure was completed in 23 patients, grafting the left anterior descending coronary artery (n = 21) or diagonal branches (n = 3, 1 sequential) as scheduled. In 1 case with internal mammary artery dissection, cardiopulmonary bypass and sternotomy became necessary. Simultaneous carotid endarterectomy was performed in 1 patient. There were two episodes of intraoperative ventricular fibrillation; no other major complications occurred. Postoperative evaluation was obtained in 16 patients (15 by angiography, 1 by Doppler echocardiography) so far and revealed adequate graft function and patency. Using specially designed instruments for internal mammary artery access and epicardial surface stabilization, minimally invasive direct coronary artery bypass grafting procedures via a minithoracotomy avoiding cardiopulmonary bypass techniques may be applied safely and successfully, even in increased risk constellations.