A systematic approach to substernal epicardial echocardiographic examination

OBJECTIVE: The importance of echocardiography in the perioperative management of cardiac surgical patients is widely appreciated. A modified mediastinal drain has been developed, which allows the introduction of a standard TEE probe in a closed-ended sleeve coupled with the drain to permit epicardial echocardiographic imaging after chest closure (substernal epicardial echocardiography [SEE]). The aim of the present study was to develop a standardized and comprehensive SEE examination sequence to allow repeatable examinations with a single movement of the TEE probe inside the drain. DESIGN: Prospective observational protocol. SETTING: Tertiary care university hospital. PARTICIPANTS: Ten adult patients undergoing elective cardiac surgery. INTERVENTIONS: Twenty-three SEE examinations in 10 patients undergoing elective myocardial revascularization to develop a standard examination sequence. MEASUREMENTS AND MAIN RESULTS: The examination sequence includes 11 views with all the structures relevant for postoperative monitoring. The entire sequence is performed with a single in-out movement of the transesophageal probe to minimize discomfort to patients and the risk of damaging the tube. CONCLUSIONS: This new approach to the perioperative monitoring of cardiac surgical patients represents an option for patients in whom TEE is contraindicated or multiple examinations are anticipated because SEE examinations can be performed without the need for sedation in awake patients.     

Substernal epicardial echocardiography: a recommended examination sequence and clinical evaluation in patients undergoing cardiac surgery

Background

Substernal epicardial echocardiography is a novel echocardiography window, utilizing a modified mediastinal drain incorporating a sleeve for the insertion of a transesophageal echocardiography probe.

Methods

Forty-six patients undergoing cardiac surgery from two institutions were evaluated, and an examination sequence was developed.

Results

An 11-view examination is presented as a consensus between the two institutions. In clinical usage, there were no major complications attributable to use of the device. Minor air leaks occurred in 6 patients, and 2 cases of sternal wound infection occurring in a cluster of infections are reported, but causation was not attributed to use of the device. There were no significant differences in measurements of the aortic valve area, pulmonary artery diameter, left ventricular outflow tract dimension, or the sinotubular junction between substernal and transesophageal examinations. All 16 wall-motion segments were well visualized in most patients with substernal epicardial echocardiography.

Conclusions

Substernal epicardial echocardiography is a safe device for use in the postoperative environment.     

Epikardiale Echokardiographie

Epicardial echocardiography has been available since the early 1970s as an intraoperative diagnostic modality to assess ventricular and valvular function. With this technique, an ultrasonic transducer is placed directly on the epicardial surface of the heart, following sternotomy and pericardiotomy. Under the guidance of the cardiac anesthesiologist, the surgeon places the transducer so that the desired views of cardiac structures and great vessels can be obtained. The anesthesiologist performs the acquisition, analysis and interpretation of the echocardiographic images. Despite the feasibility of epicardial echocardiography, transesophageal echocardiography (TEE) has emerged over the last two decades as the main form of intraoperative echocardiography. Although TEE allows continuous monitoring of cardiac and valvular function without interruption of the surgical procedure, placement of a TEE probe may be difficult or contraindicated in some patients. In such cases, epicardial echocardiography may be the optimal ultrasonographic imaging modality to assess ventricular and valvular function during cardiac surgery. We describe the use of epicardial echocardiography for intraoperative assessment of valvular function in two patients where TEE was either contraindicated or probe placement could not be performed safely. The first patient underwent surgical repair of the mitral valve for severe mitral regurgitation. After weaning the patient from cardiopulmonary bypass (CPB), epicardial echocardiography was used to confirm successful reconstruction of the valve and to exclude residual mitral regurgitation. The second patient was scheduled for coronary artery bypass grafting (CABG). Prior to the initiation of CPB, the presence of moderate aortic stenosis was confirmed using Doppler echocardiography via an epicardial approach.     

Intraoperative echocardiography for evaluation of congenital heart defects in infants and children.

To determine the accuracy, utility, and limitations of intraoperative transesophageal echocardiography (TEE) in infants and children, we performed prebypass and postbypass TEE in 90 children undergoing surgical repair of congenital heart lesions, comparing the results to those obtained using intraoperative epicardial echocardiography and pre- and postoperative precordial echocardiography. Patients ranged in age from 4 days to 21 yr (mean 4.1 yr) and in weight from 3 to 68 kg (mean 15.4 kg). Prebypass, we obtained high-quality, two-dimensional TEE images in 86 patients, with correction of the preoperative precordial diagnosis in 3 and confirmation of the preoperative diagnosis in the rest. Adequate epicardial images were obtained in 78 patients, with confirmation of the preoperative diagnosis in all. Shunt lesions that were well delineated prebypass by both TEE and epicardial imaging included interatrial, interventricular, and atrioventricular septal defect lesions. TEE failed to detect the exact size and location of lesions involving the right ventricular outflow tract, i.e., doubly committed subarterial (supracristal) ventricular septal defects. Regurgitant lesions (n = 30) were identified and their severity evaluated in all patients by both TEE and epicardial imaging. Obstructive lesions (n = 33), excluding those involving the right ventricular outflow tract, were well defined by both echocardiographic approaches. Postbypass, we obtained high-quality, two-dimensional, color and Doppler TEE images in 86 patients and epicardial images in 78 patients.(ABSTRACT TRUNCATED AT 250 WORDS)     

Transesophageal echocardiography--is it indicated for children undergoing heart surgery?]

In adults transesophageal echocardiography (TEE) has become a well-established method for the assessment of cardiac malformations. In children the transthoracic approach (TTE) gives excellent resolution and cardiac malformations can be well defined in most of the cases. Uncertainty may, nevertheless, exist in complex anomalies in spite of TTE and angiography or after surgical interventions. Recently pediatric 5-mHz TEE probes have been developed with acceptable diameters of 6, 9 and 11 mm. The feasibility and the potential risks of TEE were studied in 47 patients, aged from 5 months to 16 years (mean 5 9/12 years), weighing from 5 to 47 kg (mean 19.7 kg). 35 children had congenital malformations: 15 VSD + PS, 5 VSD + PHT, 3 ASD, 5 A-V canal malformations, 1 tricuspid atresia, 2 subvalvar aortic stenosis, 3 endocarditis, 1 normal. Twelve children had rheumatic heart disease. Eight patients had more than 1 TEE. The examination was performed either under general anaesthesia just before of after surgical intervention in 32 or under sedation and with local anaesthesia in the others. There was no complication, but in 3 intubated children under 3 years of age TEE was not possible; obstruction of the endotracheal tube occurred. Adequate imaging was obtained in most of the children with one or the other probe. Additional information was obtained in 28 patients (52%). In 5 of them these informations modified the surgical procedure. We conclude that TEE is feasible in children and has a low risk of complications when practised with care.(ABSTRACT TRUNCATED AT 250 WORDS)     

Epicardial echocardiography: diagnostic utility for evaluating aortic valve disease during coronary surgery

Intraoperative epicardial echocardiography is commonly used to evaluate the ascending aorta for atheromatous disease before cannulation and cross clamping. In addition, it may serve as a cardiac imaging technique in patients where placement of a transesophageal echocardiography (TEE) probe is contraindicated, probe advancement is difficult, or a TEE probe is not available. We report a patient who was taken to the OR for coronary artery bypass grafting. Intraoperative TEE was planned to evaluate aortic valve function. However, attempts to place a TEE probe were abandoned due to high resistance on probe insertion. Epicardial echocardiography revealed previously undiagnosed aortic valve disease resulting in replacement of this valve.     

Transesophageal echocardiography and the intraoperative management of pediatric congenital heart disease: initial experience with a pediatric esophageal 2D color flow echocardiographic probe.

Intraoperative color Doppler transesophageal echocardiography (TEE) was performed in 26 patients undergoing corrective or palliative surgery for congenital heart disease. Age ranged from 1 day to 15 years, and body weight ranged from 2.9 to 42 kg. Objectives of the study were to determine the smallest infant in whom the pediatric probe could be used safely, additional diagnostic value, and it role in the intraoperative assessment of the surgical repair. The insertion of the pediatric probe was possible in all 26 patients. The smallest infant in this series was a newborn weighing 2.9 kg. Excellent correlation was obtained with preoperative transthoracic echocardiographic findings and operative findings. Assessment of the surgical repair was obtained in the immediate postcardiopulmonary bypass period. No short-term complications occurred in this series. Intraoperative color Doppler TEE provided a detailed and accurate assessment of the morphology, the function of the heart, and altered the management of at least two patients.     

Novel use of transesophageal echocardiographic probe for intraoperative epicardial imaging

We studied 3 patients in whom standard transesophageal echocardiography was either not feasible nor offered suboptimal images. A standard multi-plane transesophageal echocardiography probe was covered in a sterile sheath containing ultrasonic gel, and the tip of the probe was placed on the beating heart by the surgeon. Echocardiographic imaging planes were selected by combining multi-plane imaging with "flexion" and "extension" of the probe by the echocardiographer, with minimal surgical manipulation. Good-quality "epicardial-transesophageal echocardiography" images were obtained in all cases, allowing effective decision-making by the surgeon. The small size of the probe and availability of multi-plane imaging allowed comprehensive and detailed imaging of the heart with minimal manipulation of the probe. There were no side effects attributable to the epicardial-transesophageal echocardiography. The new technique of epicardial echocardiography with a multi-plane transesophageal echocardiography probe overcomes the limitations of conventional transesophageal echocardiography and of epicardial echocardiography in selected patients and allows excellent visualization of cardiac structure and function with minimal interference with the surgical field, and with no extra expenditure.     

Anterior mediastinal tumour identified by intraoperative transesophageal echocardiography

PURPOSE: To report a child with anterior mediastinal tumour misdiagnosed as pericardial effusion who had been sent to the operating theatre for drainage. After induction of general anesthesia she developed cardio-respiratory collapse. The diagnosis was made with the aid of transesophageal echocardiography (TEE). CLINICAL FEATURES: A 14-yr-old girl suffered from cough and intermittent fever for one month before admission. Four days before admission, she became orthopneic and was admitted to the intensive care unit. Precordial echocardiography showed an anterior and posterior echolucent space between the pericardium and epicardium that was thought to be a pericardial effusion. She was sent to the operating room for emergency drainage. After induction of general anesthesia, breath sounds were not heard on the left side of the chest. The patient developed increasing hypoxemia and hypotension despite cardiocentesis. A TEE determined that an anterior mediastinal mass was the cause of her hypoxemia and hypotension. The tumour was debulked and the patient made an uneventful postoperative recovery. CONCLUSION: In this case, the correct diagnosis of an anterior mediastinal mass was made with TEE. The place of TEE may be indicated in patients with unexplained hypoxemia and hypotension.     

Surgical treatment of substernal goiter

BACKGROUND: Substernal goiter differs from its cervical counterpart in regard to its clinical presentation, surgical management, pathological analysis and postoperative complication. METHODS: Retrospective analysis of 1320 thyroidectomies performed at the Hacettepe University Hospital between 1990 and 1997. RESULTS: 30 (2.3%) of 1320 thyroidectomies underwent operation for removal of substernal goiters in an 8-year period. The most common symptom was cervical mass (67%) and 33% of the patients were asymptomatic. Computerised tomography was the most accurate pre-operative test for detecting substernal extension. Substernal goiters were removed by collar incisions in 93% of the cases. The pathology was generally found to be benign (94%), but follicular carcinoma was present in two (6%) patients. There was no mortality and no complications were observed in 73% of the patients. CONCLUSIONS: The presence of substernal goiter is an indication for removal given the lack of any effective medical therapy, low surgical morbidity, risk of malignancy and acute obstructing symptoms.     

Massive gastrointestinal hemorrhage after transoesophageal echocardiography probe insertion

PURPOSE: To describe a case of a massive gastric bleeding following emergency coronary artery bypass surgery associated with transoesophageal echocardiographic (TEE) examination. CLINICAL FEATURES: A 50-yr-old man was referred for an acute myocardial infarction and pulmonary edema (Killip class 3). Twelve hours after his myocardial infarction, he was still having chest pain despite an i.v. heparin infusion. Coronary angiography revealed severe three-vessel disease with multifocal stenosis of the left anterior descending, circumflex and total occlusion of the right coronary artery. The patient was transferred to the operating room for emergency coronary artery bypass graft surgery. After total systemic heparinization (3 mg.kg-1) was obtained for cardiopulmonary bypass, a multiplane TEE probe was inserted without difficulty to monitor myocardial contractility during weaning from CPB. During sternal closure, the TEE probe was removed and an orogastric tube was inserted with immediate drainage of 1,200 ml red blood. Endoscopic examination demonstrated a mucosal tear near the gastro-oesophageal junction and multiple erosions were seen in the oesophagus. These lesions were successfully treated with submucosal epinephrine injections and the patient was discharged from the hospital eight days after surgery. CONCLUSION: This is a report of severe gastrointestinal hemorrhage following TEE examination in a fully heparinized patient. This incident suggest that, if the use of TEE is expected, the probe should preferably be inserted before the administration of heparin and the beginning of CPB.     

The safe use of intraoperative transesophageal echocardiography in the management of total anomalous pulmonary venous connection in newborns and infants: a case series

BACKGROUND: Intraoperative transesophageal echocardiography (TEE) is useful in evaluating the repair of lesions in patients with congenital heart disease. But the use of TEE in infants with total anomalous pulmonary venous connection (TAPVC) remains unclear. We reviewed the safety and efficacy of intraoperative TEE during TAPVC repair. METHODS: Twenty-eight consecutive 1 day to 7 month-old infants with TAPVC (14 supracardiac, six intracardiac and eight infracardiac type) had surgical repair with intraoperative TEE monitoring. RESULTS: Four patients received immediate surgical revision after primary surgery for residual anastomotic stenosis diagnosed by TEE. In addition, two unsuspected ventricular septal defects and three persistent ductus arteriosus were detected before surgery. Eight infants (29%) had hypotension and hypoxemia associated with TEE probe insertion before surgery, but this hemodynamic disturbance returned to baseline value after withdrawing the TEE probe from the esophagus. However, these eight patients had uneventful TEE probe insertion following sternotomy. The mechanism was probably because of the reduction of intrathoracic pressure when the chest was opened. CONCLUSIONS: TEE probe insertion in TAPVC patients may pose a potential risk of compression of pulmonary venous confluence resulting in hemodynamic instability. Therefore, we suggest that the use of TEE in such TAPVC patients appears to be safer after sternotomy.     

Application of intraoperative transesophageal echocardiography in infants and small children

Intraoperative echocardiography is gaining increasing acceptance in the assessment of the surgical repair of congenital heart defects. Because of its ideal imaging location, intraoperative transesophageal echocardiography (TEE) has been especially helpful in evaluating pulmonary venous return and the integrity of the left atrioventricular valve following mitral valvuloplasty, complete atrioventricular valve repair and correction of complex congenital heart disease. It has not been routinely used in infants and small children because of a prohibitively large probe size. We report the successful use of a recently developed "pediatric" TEE probe capable of Doppler and color flow imaging in two patients less than 7 years of age. No complications were encountered. Recommendations regarding optimal probe imaging positions in infants are provided.     

Correlations between global clotting function tests, duration of operation, and postoperative chest tube drainage in pediatric cardiac surgery

Background: Systemic coagulation disorders after cardiac surgery represent serious postoperative complications. There have been few reports, however, identifying preoperative coagulation tests that predict postoperative bleeding. The aim of the present study was to investigate the relationship between postoperative hemorrhage and coagulation parameters determined by global coagulation assays, to define potential predictive markers. Methods: Twenty‐one pediatric patients were enrolled. Blood samples were collected before and 24 h after cardiac surgery. Laboratory investigations included platelet count, hematocrit, classical coagulation tests [prothrombin time, activated partial thromboplastin time, thrombin‐antithrombin complex (TAT)], rotation thromboelastometry (ROTEM), and the thrombin generation test (TGT). The duration of the surgical procedure was recorded. Chest tube drainage was monitored for 24 h after operation as an index of postoperative hemorrhage. Results: Comparisons between preoperative and postoperative results indicated that TAT increased significantly after operation, whereas ROTEM parameters did not show a hypercoagulable pattern. Preoperative endogenous thrombin potential (ETP) measured in the TGT and clot formation time (CFT) in the ROTEM correlated with chest tube drainage. The classical coagulation tests were not informative. Postoperatively, peak height and ETP in TGT, all ROTEM parameters, and duration of surgery were correlated with chest tube drainage. Duration of surgery was correlated with postoperative ROTEM parameters but not with TGT. Postoperative maximum clot firmness and AUC were correlated with platelet count decrease ratio. Conclusions: The preoperative CFT and ETP provide useful indices for predicting postoperative chest tube drainage volume. In addition, the duration of surgery also correlated with chest tube drainage and affected ROTEM parameters.     

The effects of transesophageal echocardiography on hemodynamic variables in small infants undergoing cardiac surgery

OBJECTIVE: To assess the effects of transesophageal echocardiography (TEE) on hemodynamic variables during cardiac surgery in small infants. DESIGN: A prospective clinical study. SETTING: A medical college-affiliated tertiary care children's hospital. PARTICIPANTS: Twenty-three infants weighing 2 to 5 kg undergoing cardiac surgery. INTERVENTIONS: Baseline heart rate, arterial pressure, and central venous pressure were recorded. A pediatric TEE probe was inserted, and the hemodynamic variables were again recorded. Postoperatively the hemodynamic measurements were measured again before and after probe removal, with the addition of left atrial pressure and pulmonary artery pressure when available. Hemodynamic parameters were carefully observed during all phases of the TEE examinations for any changes attributable to probe manipulation. MEASUREMENTS AND MAIN RESULTS: No statistically significant changes occurred in this group of patients during TEE. No clinically significant changes in any individual patient occurred during the measurement or during manipulation of the TEE probe for the complete examination. CONCLUSION: Although hemodynamic compromise can occur in small infants, this study suggests that it is infrequent. Fear of hemodynamic compromise should not prevent use of intraoperative TEE in small infants when otherwise indicated.     

The safety of intraoperative transesophageal echocardiography: a case series of 7200 cardiac surgical patients

Transesophageal echocardiography (TEE) is an invaluable intraoperative diagnostic monitor that is considered to be relatively safe and noninvasive. Insertion and manipulation of the TEE probe, however, may cause oropharyngeal, esophageal, or gastric trauma. We report the incidence of intraoperative TEE-associated complications in a single-center series of 7200 adult cardiac surgical patients. Information related to intraoperative TEE-associated complications was obtained retrospectively from the intraoperative TEE data form, routine postoperative visits, and cardiac surgical morbidity and mortality data. The overall incidences of TEE-associated morbidity and mortality in the study population were 0.2% and 0%, respectively. The most common TEE-associated complication was severe odynophagia, which occurred in 0.1% of the study population. Other complications included dental injury (0.03%), endotracheal tube malpositioning (0.03%), upper gastrointestinal hemorrhage (0.03%), and esophageal perforation (0.01%). TEE probe insertion was unsuccessful or contraindicated in 0.18% and 0.5% of the study population, respectively. These data suggest that intraoperative TEE is a relatively safe diagnostic monitor for the management of cardiac surgical patients. IMPLICATIONS: The overall morbidity (0.2%) and mortality (0%) rates of intraoperative transesophageal echocardiography (TEE) were determined in a retrospective case series of 7200 adult, anesthetized cardiac surgical patients. The most common source of TEE-associated morbidity was odynophagia (0.1%), which resolved with conservative management. These results suggest that TEE is a safe diagnostic tool for the management of cardiac surgical patients.     

Delayed diagnosis of esophageal perforation following intraoperative transesophageal echocardiography during valvular replacement--a case report

A 62 year-old man sustained esophageal perforation following intra-operative transesophageal echocardiography (TEE) in a valvular replacement surgery. Septic shock developed on the 12th postoperative day (POD) and the esophageal perforation was diagnosed with chest CT. Emergent operation together with intensive care saved the patient's life. We speculate that the mechanism of perforation was not due to manipulation of the probe, but rather due to ischemia of the esophagus resulting from the combination of probe compression, non-pulsatile flow and the distension of the atria during a lengthy procedure. It is advisable that in patients with operative risk factors, such as distension of atria, long cardiac procedure and likely ischemia of organs due to cardiopulmonary bypass, the monitoring probe of TEE should not constantly rest in the esophagus and be withdrawn when it is idle or not in actual use. In addition, if resistance has been met during the intraoperative manipulation of the probe in a patient without previous history of esophageal disease, perforation might suspected if he or she sustains postoperative fever with positive chest X-ray findings.     

Cardiovascular evaluation in blunt thoracic trauma using transesophageal echocardiography (TEE)

Blunt chest trauma can result in significant cardiothoracic injury, which can include cardiac contusion, aortic injury, and myocardial valvular injury. Nineteen patients with no prior history of cardiac abnormalities who sustained severe blunt chest trauma and had widening of the mediastinum on chest radiographs were prospectively evaluated using transesophageal echocardiography (TEE). In each instance TEE was performed without difficulty, excellent images were obtained of the aorta and heart, and no complications were noted. Abnormalities were seen in 12 (63%) patients, with hypokinetic regional wall motion consistent with cardiac contusion demonstrated in five (26%) patients. Tricuspid regurgitation was found in three (16%) patients, and aortic and mitral regurgitation in one (5%) patient each. Aortic wall hematomas were seen in two patients, one of whom had an intimal tear on aortography, and a pericardial effusion was seen in one patient with an aortic intimal tear confirmed angiographically. Thus TEE can be performed safely in the acute setting of patients sustaining severe blunt chest trauma and yield useful information with respect to cardiovascular function and the aorta.     

How soon should drainage tubes be removed after cardiac operations?

Pericardial effusion frequently occurs after cardiac operation. Despite its high incidence, the etiological process of postoperative pericardial effusion remains unclear. Residual blood or thrombus has often been suggested as a possible cause, implying that the occurrence of pericardial effusion could be related to the effectiveness of postoperative thoracic drainage. This possible relationship, however, has never been studied. We found that prolonging the duration of thoracic drainage by 24 hours often increases total chest tube output considerably but does not affect the incidence of postoperative pericardial effusion: approximately 55% of 100 patients in this study were shown by two-dimensional echocardiography to have pericardial effusion on the sixth postoperative day, regardless of the duration of postoperative drainage. Because of this, and because a long period of drainage causes discomfort for the patient, mechanical irritation to the heart and the pericardium, and an increased risk of infection, we recommend removing drains as soon as their efficacy has peaked, preferably on the first postoperative day.