Transesophageal echocardiographic monitoring of myocardial ischemia during vascular surgery

[Anesthesiologic procedure for elective aortic surgery]

Aortic aneurysms are frequent in the elderly who often suffer from relevant co-morbidities. In Germany it is estimated that approximately 250,000 patients suffer from an aortic aneurysm. Due to the high risk of cardiac or pulmonary complications operative management poses a challenge to the anesthesiologist. Especially hemodynamic management during aortic cross-clamping requires anesthesiologic know-how and an anticipatory use of vasodilators and catecholamines. Furthermore, the anesthesiologist has to protect renal function. In order to avoid paraplegia due to spinal ischemia cerebrospinal fluid drainage may be necessary in patients with aneurysms of the thoracic aorta. In recent years endovascular repair of aortic aneurysms has been established in addition to conventional open surgery. As a consequence in some patients aortic surgery can be performed under regional or local anesthesia. In special cases thoracic endovascular repair requires a medicinal induction of heart arrest or the reduction of aortic blood flow by overpacing.

Transesophageal echocardiography and noncardiac surgery

The use of transesophageal echocardiography (TEE) for monitoring during cardiac and noncardiac surgery has increased exponentially over the past few decades. TEE has evolved from a diagnostic tool to a monitoring device and a procedural adjunct. The close proximity of the TEE transducer to the heart generates high-quality images of the intracardiac structures and their spatial orientation. The use of TEE in noncardiac and critical care settings is not well studied, and the evidence of the benefits of its use in these settings is lacking. Despite the widespread availability of TEE equipment in US hospitals, less than 30% of anesthesiologists are formally trained in the use of perioperative TEE. In this review, the safety and indications of TEE are reviewed and detailed analysis of the best available evidence in this regard is presented. Landmark trials evaluating the use of TEE and its therapeutic impact in noncardiac surgical setting are critically reviewed. This article details recommendations to familiarize anesthesiologists with TEE technology to exploit it to its fullest potential to achieve better patient monitoring standards and eventually improve outcome. Training of greater numbers of anesthesiologists in TEE is needed to increase awareness of the indications and contraindications. Until relatively inexpensive TEE equipment is available, the initial cost of equipment acquisition remains a significant prohibitive factor limiting its widespread use.

The usefulness of transesophageal echocardiography during intraoperative cardiac arrest in noncardiac surgery

According to guidelines established by the American Society of Anesthesiologists and the Society of Cardiovascular Anesthesiologists, life-threatening hemodynamic disturbances are classified as a category I indication for the intraoperative use of transesophageal echocardiography (TEE). However, the usefulness of TEE during intraoperative cardiac arrest and its impact on patient management have not been rigorously investigated. Using our departmental TEE database, we identified a population of 22 patients who underwent noncardiac surgical procedures and experienced unexpected intraoperative hemodynamic collapse requiring the initiation of Advanced Cardiac Life Support procedures between the time of induction of general anesthesia and the termination of the surgical procedure. Results of TEE examinations, patient records, detailed operative records, and outcome of patients were reviewed for the utility of TEE to diagnose the etiology of the hemodynamic collapse. Furthermore, the impact on subsequent patient management was evaluated. A primary suspected diagnosis of the underlying pathological process was established in 19 of 22 patients with TEE, including 9 with thromboembolic events, 6 with acute myocardial ischemia, 2 with hypovolemia, and 2 patients with pericardial tamponade. A definitive diagnosis could not be made in 3 patients with TEE. In 18 patients, TEE guided specific management beyond implementation of Advanced Cardiac Life Support protocols, including the addition of surgical procedures in 12 patients. Fourteen patients survived to leave the operating room, and 7 of these patients were eventually discharged from the hospital. Thus, TEE may provide additional diagnostic information in patients with intraoperative cardiac arrest and may directly guide specific, potentially life-saving therapy.

Role of Intraoperative Transesophageal Echocardiography in Patients Having Coronary Artery Bypass Graft Surgery

BACKGROUND

Previous studies have shown that intraoperative transesophageal echocardiography provides important preoperative and postoperative information in various cardiac and noncardiac surgeries that may alter patient management and outcome. The role of intraoperative transesophageal echocardiography in patients in whom isolated coronary artery bypass graft surgery is anticipated has been reported only in small selected groups. This study was designed to prospectively evaluate the role of intraoperative transesophageal echocardiography in a large, nonselected group of patients undergoing primarily coronary artery bypass graft surgery.

METHODS

From January 2001 to December 2003, 474 consecutive patients (76% men, 24% women) aged 30 to 89 years (mean age of 70 +/- 10 years) who were undergoing coronary artery bypass graft surgery had prebypass and postbypass intraoperative transesophageal echocardiography. New findings and alterations in the surgical plan were documented prospectively.

RESULTS

New prebypass findings were found in 10% of patients, and the surgical plan was altered in 3.4% of patients. New postbypass findings were found in 3.2% of patients, altering the surgical plan in 2% of patients.

CONCLUSIONS

This large consecutive, nonselected, prospective study reveals the significant impact of intraoperative transesophageal echocardiography in patients having coronary artery bypass graft surgery as a primary procedure. New findings (prebypass and postbypass) were found in 13% of patients overall, and the surgical plan was altered in 5.5% of patients. This study supports the use of intraoperative transesophageal echocardiography in patients undergoing primarily coronary artery bypass graft surgery.

Quantitative analysis of left ventricular regional wall motion with color kinesis during abdominal aortic cross-clamping

OBJECTIVES

The authors aimed to establish a technique for quantitative analysis of regional wall motion abnormality (RWMA) using color kinesis (CK) of transesophageal echocardiography (TEE) in surgical patients. This technique was used to determine whether RWMAs develop de novo after infrarenal aortic cross-clamping in patients undergoing vascular surgery with a preoperative dipyridamole thallium stress test (DTST).

DESIGN

An observational study.

SETTING

University hospital.

PARTICIPANTS

Thirty-eight patients undergoing infrarenal abdominal aortic aneurysm resection or aortofemoral bypass.

MEASUREMENTS AND MAIN RESULTS

CK images of the left ventricle (LV) were obtained from the midventricular transgastric short-axis view before and after infrarenal aortic cross-clamping using TEE and analyzed off-line using custom software. The predictive value of the category "reversible perfusion defect" (RD) was also estimated from DTST for predicting new RWMAs with CK. CK analysis is suitable for clinical use based on the comparison with conventional two-dimensional echocardiogram measurements and interobserver variability. CK analysis showed all 7 patients with persistent perfusion defects on DTST had RWMAs. New RWMAs occurred in 2 of 9 patients with RD and in 2 of 15 patients with normal DTST, indicating that there was no significant difference between RD and normal DTST in the incidence of new RWMAs.

CONCLUSIONS

A new method is available for clinical use, which is capable of visualizing RWMAs. These results suggest that new RWMAs introduced by aortic cross-clamping occur irrespective of the risk as assessed by preoperative DTST. CK with the new analysis method might be a useful tool to quantitatively evaluate RWMAs during surgery.

Randomized study comparing cardiac response in endovascular and open abdominal aortic aneurysm repair

BACKGROUND

The aim was to compare the cardiac response and the incidence of adverse cardiac events during and after endovascular (EVAR) and open (OR) repair of abdominal aortic aneurysms (AAAs).

METHODS

Seventy-six patients with an AAA suitable for EVAR, and in a general condition allowing open surgery were randomized to EVAR (57 patients) or OR (19 patients). The analysis was on an intention-to-treat basis. Haemodynamic variables were assessed intraoperatively before, during and after aortic occlusion. During the procedure myocardial ischaemia was identified with use of electrocardiography (ECG) and transoesophageal echocardiography (TEE). After operation, cardiac complications were diagnosed by clinical observation, 12-lead ECG at 1 h, 1 day and 7 days, echocardiography at 1 month and measurement of cardiac enzymes.

RESULTS

After aortic occlusion, a greater decrease in systemic vascular resistance compared with baseline was observed with OR than with EVAR (- 396 and - 70 dyne s/cm5 respectively; P = 0.03). The stroke work index, as a direct measure of myocardial performance, demonstrated a decrease during OR and an increase during EVAR during aortic occlusion (- 6.6 and + 1.7 g m/m2 respectively; P = 0.03) as well as after aortic occlusion (- 7.6 and + 3.4 g m/m2 respectively; P < 0.01), compared with baseline. The incidence of postoperative clinical cardiac complications was comparable in the two study groups; however, myocardial ischaemia, as observed by ECG and TEE, was observed more frequently in the OR group (ten of 19 versus 15 of 57 patients; P = 0.05).

CONCLUSION

Haemodynamic changes were less severe and there was a lower incidence of myocardial ischaemia during EVAR than during OR. Studies are needed to demonstrate whether this may reduce the operative mortality rate.

Monitoring Perioperative Ischemia

This report addresses monitoring for ischemia during surgery and whether perioperative ischemia leads to increased morbidity and mortality in patients with cor onary artery disease (CAD) who are undergoing sur gery. Based on previous studies, it is generally accepted that perioperative ischemia is common in patients with CAD undergoing noncardiac surgery. The incidence of ischemia during the operative period varies greatly with cardiac risk factors, type of surgery, duration of surgery, and the monitor used to detect ischemia. Be cause perioperative cardiac morbidity is the leading cause of death after anesthesia and surgery, it is pru dent for the anesthesia clinician to have an understand ing of the tools available for monitoring as well as their clinical utility. These tools are summarized, and recom mendations are made regarding their use.

Intraoperative transesophageal echocardiography: 5-year prospective review of impact on surgical management

OBJECTIVE

To determine the impact of intraoperative transesophageal echocardiography (IOTEE), an important adjunct in many types of cardiac surgical cases, on the surgical decisions made perioperatively in adult patients undergoing cardiac surgery.

PATIENTS AND METHODS

All adult patients who had cardiac surgery between 1993 and 1997 and who also had IOTEE were studied. New findings before and after cardiopulmonary bypass and alterations in the planned surgical procedure or management were documented prospectively.

RESULTS

A total of 3245 patients (60% men, 40% women; aged 18-93 years with a mean +/- SD age of 62 +/- 15 years) were included in the study. The most common operations performed were mitral valve repair (26%) and aortic valve replacement (22%). Over the 5-year period, 41% of patients had IOTEE. New information was found before bypass in 15% of patients, directly affecting surgery in 14% of the patients. The most common new prebypass information found was patent foramen ovale resulting in closure in the majority of patients. New information was found after bypass in 6% of the patients, resulting in a change in surgery or hemodynamic management in 4% of the total. The most common postbypass finding was valvular dysfunction with repeat bypass in most patients for re-repair or replacement. No major complications occurred.

CONCLUSION

In adult patients undergoing cardiac surgery, IOTEE provides important important information both before and after bypass that affects surgical and hemodynamic management.

Effects of anesthetic technique on myocardial wall motion abnormalities during abdominal aortic surgery

OBJECTIVE

To assess the impact of regional supplemented general anesthesia (RSGEN) on regional myocardial function during abdominal aortic surgery (AAS).

DESIGN

Prospective randomized study.

SETTING

Single academic medical center.

PARTICIPANTS

Seventy-three patients scheduled for infrarenal aortic aneursymectomy.

INTERVENTIONS

Patients received standardized intraoperative anesthetic management consisting of either general anesthesia (GA; n = 37) or general anesthesia supplemented by epidural anesthesia (RSGEN; n = 36).

MEASUREMENTS AND MAIN RESULTS

Hemodynamic measurements and transesophageal echocardiograms (TEE) were obtained at eight intraoperative times. The electrocardiogram (ECG) was continuously recorded using Holter monitoring. Of the 56 patients with interpretable TEE recordings, 8 of 30 (27%) GA patients and 7 of 26 (27%) RSGEN patients developed new segmental wall motion abnormalities (SWMAs). There was no treatment effect on either the incidence (p = 0.23) or the intensity (p = 0.34) of SWMAs. Cross-clamping of the aorta was associated with the onset of new SWMAs (odds ratio, 8.2; 95% CI, 1.1 to 64; p = 0.04). Among the 63 patients with interpretable Holter recordings, 9 of 34 (26%) GA patients and 9 of 29 (31%) RSGEN patients exhibited intraoperative ischemia. There was no treatment effect on the incidence (p = 0.22) or intensity (p = 0.67) of ECG ischemia.

CONCLUSION

Despite providing modest hemodynamic depression, RSGEN did not reduce the incidence or intensity of either regional myocardial dysfunction or ECG ischemia. New SWMAs were temporally associated with cross-clamping of the aorta and tended to resolve with unclamping.

Effects of nitroglycerin infusion on segmental wall motion abnormalities after anesthetic induction

OBJECTIVES

To assess the effect of intravenous nitroglycerin (NTG) on segmental wall motion abnormalities (SWMAs) and global ventricular function after anesthetic induction in patients undergoing coronary artery bypass grafting (CABG).

DESIGN

Prospective study.

SETTING

University hospital.

PARTICIPANTS

Twenty patients scheduled for elective CABG.

INTERVENTIONS

Patients demonstrating SWMAs in at least two myocardial segments after induction received intravenous NTG at 2 micrograms/kg/min.

MEASUREMENT AND MAIN RESULTS

Transesophageal echocardiography (TEE) was performed before and after the NTG infusion for analysis of segmental wall motion abnormalities. Mean arterial pressure (MAP), central venous pressure, and pulmonary capillary wedge pressure decreased significantly after NTG infusion, whereas cardiac index and heart rate remained unchanged. End-diastolic area and end-systolic area decreased, and consequently fractional area change increased significantly. Two of 20 patients (10%) showed electrocardiogram evidence of ischemia after induction. After NTG infusion, 15 of 20 patients (75%) showed an increase in a wall motion score more than two points. In these 15 patients with NTG-responsive wall motion abnormalities, the mean ratio of peak early diastolic filling velocity (E) to peak late diastolic filling velocity (A) increased from 0.89 +/- 0.20 to 1.04 +/- 0.25 (p < 0.01) after NTG infusion despite a decrease in filling pressure. Systolic wall thickening improved in segments with poor preoperative function from a pre-NTG value (mean +/- SD) of -1.0% +/- 7.4% to a post-NTG value of 31.4% +/- 24.9% (p < 0.01).

CONCLUSIONS

Intravenous NTG improved postinduction SWMAs in 75% of patients with known coronary artery disease. TEE-guided NTG infusion after induction may provide an optimal baseline echocardiogram for monitoring intraoperative myocardial ischemia by improving the reversible portion of postinduction SWMAs.

Role of echocardiography in perioperative management of patients undergoing open heart surgery

TEE has assumed a pivotal role in the perioperative management of patients undergoing open-heart surgery. The information obtained influences important therapeutic decisions in thoracic aortic surgery, valvular surgery, and coronary artery bypass surgery. TEE also assists in determining the reason for failure to wean from cardiopulmonary bypass and allows rapid detection of the etiology of hypotension in the patient after surgery. Advances in technology have resulted in three-dimensional images of cardiac structures, and this will further enhance the usefulness of echocardiography for the surgeon. TEE should no longer be regarded as an imaging tool available only in academic centers, but should be routinely used by qualified operators in centers performing open-heart surgery.

Choice of anesthesia and intraoperative monitoring for lower extremity revascularization

The prevalence of significant coronary artery disease re-enforces the importance of careful preoperative and intraoperative management in patients undergoing lower extremity revascularization. This article presents a practical approach toward the evaluation of anesthetic risk and the proper use of anesthetic agents and monitoring devices to minimize morbidity. The role of general and regional anesthetic agents is discussed, and complications of both techniques are presented.

Transesophageal dobutamine stress echocardiography in the evaluation of coronary artery disease

OBJECTIVES

The goal of this study was to determine the feasibility, safety, sensitivity and specificity of transesophageal dobutamine stress echocardiography for the detection of coronary artery disease.

BACKGROUND

Dobutamine stress echocardiography has been shown to be an extremely sensitive and specific noninvasive technique for the detection of myocardial ischemia. However, inadequate transthoracic images preclude the use of dobutamine stress echocardiography in a small but significant group of patients. Transesophageal echocardiography provides better resolution than that obtained with routine transthoracic imaging.

METHODS

Patients scheduled for routine cardiac catheterization underwent transesophageal dobutamine stress echocardiography. All patients underwent coronary arteriography within 48 h of the study, and lesion severity was determined by quantitative coronary angiography. Significant coronary obstruction was defined as stenosis > 50%.

RESULTS

Fifty-one male patients were enrolled in the study; six were excluded for technical reasons. There were no adverse outcomes or complications. Of 27 patients with significant coronary artery disease, 22 had positive study results (sensitivity 82%). Of 13 patients without significant obstructive coronary disease, 1 had a false positive study result (specificity 93%). In patients with a minimal lumen diameter < 1.25 mm, sensitivity was > 80%, and in patients with a minimal lumen diameter > 1.5 mm, sensitivity was < 70%, suggesting that lesions with a minimal lumen diameter < 1.25 mm are more likely to be physiologically significant.

CONCLUSIONS

Transesophageal dobutamine stress echocardiography is a feasible, safe and accurate technique for the detection of myocardial ischemia. There are inherent limitations to this technique in that transesophageal echocardiography must be performed. Transesophageal dobutamine stress echocardiography may allow extension of dobutamine stress testing to patients with inadequate transthoracic echocardiographic imaging and may provide an opportunity for further research applications.

Southwestern Internal Medicine Conference: clinical applications of transesophageal echocardiography

Transesophageal echocardiography has emerged recently as a powerful cardiac imaging tool. The strengths and limitations of transesophageal echocardiography are reviewed. The clinical use of transesophageal echocardiography in aortic dissection, endocarditis, mitral valve disease, prosthetic heart valves, stroke, and miscellaneous other conditions is discussed.

Transesophageal echocardiography for hemodynamic management of thoracoabdominal aneurysm repair

Maintenance of cardiovascular stability during thoracoabdominal aneurysm repair remains a formidable challenge. Transesophageal echocardiography (TEE) has been shown to be an excellent method for detecting myocardial ischemia and assessing left ventricular volume. We examined the utility of TEE in a group of 17 patients from an overall series of 33 patients who underwent thoracoabdominal aneurysm resection between 1988 and 1992. The mortality rate was 9%, whereas the incidences of myocardial infarction and paraplegia were 13% and 6%, respectively. Intraoperative management was significantly altered by TEE data in nine patients. Two patients were noted to have mitral valve insufficiency, and one had transient ischemia-induced regional wall abnormalities. In six patients, Swan-Ganz-derived filling data failed to identify severe hemodynamic alterations that were noted on TEE. Five patients were hypovolemic and hyperdynamic, whereas one was in florid congestive heart failure. Further investigation is warranted to prospectively validate this technique.

Perioperative care of the elderly patient

Surgical risk increases with age, primarily from loss of cardiac and pulmonary reserve. Complications are tolerated poorly by the elderly, emphasizing the importance of their prediction and prevention. Surgical risk in this population is significant, but with careful preoperative assessment and perioperative management acceptable morbidity and mortality are possible. This review proposes a general approach to the elderly surgical patient and applies it to the most significant sources of morbidity and mortality: pulmonary and cardiac complications. Risk assessment based on validated tools is utilized, and perioperative management recommendations based on the state of the art are examined. In addition, pulmonary embolism and postoperative confusion are examined separately with the same overall strategy.

Evaluation of biplane color Doppler transesophageal echocardiography in 200 consecutive patients

BACKGROUND

We developed the first biplane transesophageal echocardiography (TEE) probe with two orthogonal transducers, allowing synchronous side-by-side displays of the heart on a monitor TV, and compared its diagnostic value with that of conventional single-plane TEE using commercially available Doppler equipment in 200 consecutive patients intraoperatively, perioperatively, or on an outpatient basis.

METHODS AND RESULTS

Insertion was easy, except in one patient with a mediastinal tumor, and no complications were encountered. Both transverse and longitudinal scans allowed correct identification of true and false lumina in all 30 aortic dissection examinations, but longitudinal scanning was slightly superior in detecting types I and III entry sites. Three entries that were not detected by transverse scanning (two of DeBakey type I and one of type III) were visualized by longitudinal scanning. Among 37 cases of mitral regurgitation (MR), longitudinal scans were significantly superior (p less than 0.05) in revealing multiple jets (nine compared with two with transverse scanning). Although both planes yielded almost identical mean values for the maximum jet areas, a difference of over 50% in jet area size on the two planes was observed in 19 cases. The measured jet areas showed significant correlation with the angiographic MR grading, especially for the larger of the biplane measurements (p less than 0.01), and different grades showed little overlap. Longitudinal images increased the acoustic window of the heart and aorta from the esophagus. Moreover, longitudinal scanning provided good visualization of both ventricular outflow tracts, the ascending aorta, main pulmonary artery, and superior vena cava.

CONCLUSIONS

This modality greatly facilitates a three-dimensional comprehension of cardiovascular lesions and flow dynamics, especially in aortic dissection and MR, and its safety was demonstrated. Our data demonstrate the usefulness of this new technique in comparison with conventional single-plane TEE.

Intraoperative transesophageal Doppler color flow imaging used to guide patient selection and operative treatment of ischemic mitral regurgitation

BACKGROUND

Intraoperative transesophageal Doppler color flow imaging (TDCF) affords the opportunity to assess mitral valve competency immediately before and after cardiopulmonary bypass (CPB). The purpose of this study was to assess the utility of TDCF to assist in the selection and operative treatment of ischemic mitral regurgitation (MR).

METHODS AND RESULTS

Two hundred forty-six patients undergoing surgery for ischemic heart disease were prospectively studied. All had preoperative cardiac catheterization. Catheterization and pre-CPB TDCF were discordant in their estimation of MR in 112 patients (46%). Compared with patients in whom both techniques agreed in estimation of MR, patients with discordance in MR were more likely to have had unstable clinical syndromes at the time of catheterization (79% versus 40%, p less than 0.05) or to have received thrombolytics (16% versus 8%, p less than 0.05). Pre-CPB TDCF resulted in a change in the operative plan with respect to the mitral valve in 27 patients (11%). Because less MR was found by TDCF than catheterization, 22 patients had only coronary bypass grafting when combined coronary bypass and mitral valve surgery had been planned. Because more MR was found by TDCF than catheterization, five patients had combined coronary bypass and mitral valve surgery when coronary bypass alone had been planned. Unsatisfactory results noted by TDCF following mitral valve surgery in five patients resulted in immediate corrective surgery. Cox regression analysis identified residual MR at the completion of surgery to be an important predictor of survival (chi 2 = 21.4) after surgery--more important than patient age (chi 2 = 8.3) or left ventricular ejection fraction (chi 2 = 5.3).

CONCLUSIONS

These results indicate that TDCF is useful in guiding patient selection and operative treatment of ischemic MR and that in such patients, intraoperative TDCF should be performed routinely.

Transesophageal real-time echocardiography in infants and children with congenital heart disease

Transesophageal echocardiography using Doppler color flow mapping with both single plane transverse and longitudinal pediatric probes was performed in 127 infants and children both intraoperatively and postoperatively. The 127 patients ranged in age from 1 day to 18 years (mean 37 months) and in weight from 2.4 to 45 kg (mean 13.2); 157 studies were successfully performed (100% of attempted) with no complications. Transesophageal two-dimensional echocardiography combined with pulsed wave Doppler ultrasound and color flow mapping provided detailed morphologic as well as physiologic information, with additional information provided overall in 56% of the cases. Typical limitations of single-plane transverse imaging were overcome using a prototype longitudinal-axis pediatric probe. Both left and right ventricular outflow tracts, distal pulmonary arteries and all of the interventricular and atrial septa were visualized. Assessment of surgical repair intraoperatively as well as assessment postoperatively for cardiac function, residual intracardiac shunts, residual valvular sequelae and other hemodynamic events was important and easily performed in an otherwise inaccessible patient. Transesophageal echocardiography in infants and in small children is a valuable "noninvasive" imaging technique that offers important additional and complementary information.

Comparison of the findings on preoperative dipyridamole perfusion scintigraphy and intraoperative transesophageal echocardiography: implications regarding the identification of myocardium at ischemic risk

The evidence of myocardium at potential ischemic risk on preoperative dipyridamole perfusion scintigraphy was compared with that of manifest ischemia on intraoperative transesophageal echocardiography in 26 patients at high risk of a coronary event undergoing noncardiac surgery. The clinical outcome was also assessed. Induced intraoperative wall motion abnormalities were more common in patients and myocardial segments with, than in those without, a preoperative reversible perfusion defect (both p less than 0.05). Conversely, a preoperative reversible perfusion defect was more common in patients and segments with, than in those without, a new intraoperative wall motion abnormality (both p less than 0.05). Six patients, five with a reversible scintigraphic defect but only three with a new wall motion abnormality, had a hard perioperative ischemic event. Events occurred more often among patients with, than in those without, a reversible perioperative scintigraphic defect (5 [33%] of 15 vs. 1 [9%] of 11) but this difference did not reach significance (p = 0.14), probably owing to the sample size. Intraoperative wall motion abnormalities were all reversible and did not differentiate between risk groups; these findings were possibly influenced by treatment. These preliminary data support the known relation between reversible scintigraphic defects and perioperative events and identify another manifestation of ischemic risk in the relation between reversible scintigraphic defects and induced intraoperative wall motion abnormalities. The value of intraoperative echocardiography in identifying ischemia and guiding therapy in patients with a reversible scintigraphic abnormality should be further assessed.

Supraceliac clamping: an underused alternative in aortic surgery

In the majority of patients undergoing abdominal aortic surgery, proximal clamping can be readily achieved below the renal vessels. In some situations however, this may be difficult, impossible or ill advised, and an alternative method of control must be sought. We describe the technique and report our personal experience with supraceliac clamping, a maneuver which merits more widespread use in emergency and difficult infrarenal aortic surgery.

The utility of transesophageal echocardiography and Doppler color flow imaging in patients undergoing cardiac valve surgery

To assess the value of intraoperative transesophageal echocardiography during cardiac valve surgery, 154 consecutive patients who had a valve operation in conjunction with pre- and postcardiopulmonary bypass transesophageal imaging were studied. Prebypass imaging yielded unsuspected findings that either assisted or changed the planned operation in 29 (19%) of the 154 patients. Imaging immediately after bypass revealed unsatisfactory operative results that necessitated immediate further surgery in 10 (6%) of the 154 patients. Postbypass left ventricular dysfunction, prompting administration of inotropic agents, was identified in 13 patients (8%). Transesophageal echocardiography proved most useful when both two-dimensional and Doppler color flow imaging were employed in patients undergoing a mitral valve operation, where surgical decisions based on echocardiographic results were made in 26 (41%) of 64 cases. Postbypass echocardiographic findings identified patients at risk for an adverse postoperative outcome. Of 123 patients whose postbypass valve function was judged to be satisfactory, 18 (15%) had a major postoperative complication and 6 (5%) died, whereas of 7 patients with moderate residual valve dysfunction, 6 (86%) had a postoperative complication and 3 (43%) died (p less than 0.05 for both). Likewise, of 131 patients with preserved postbypass left ventricular function, 12 (9%) had a major complication and 7 (5%) died, whereas of 23 patients with reduced ventricular function, 17 (73%) had a postoperative complication and 6 (26%) died (p less than 0.05 for both). These data indicate that intraoperative transesophageal echocardiography is useful in formulating the surgical plan, assessing immediate operative results and identifying patients with unsatisfactory results who are at increased risk for postoperative complications.

Intraoperative management of abdominal aortic aneurysms. The anesthesiologist's viewpoint

Factors that influence the choice of anesthetic, monitoring methods, and fluid management for aneurysm repair are reviewed, with particular attention to epidural anesthesia and analgesia and the pulmonary artery catheter. Management of bleeding, renal preservation, temperature control, and myocardial ischemia are discussed, and special anesthetic issues associated with ruptured aneurysms and juxtarenal and suprarenal surgery are summarized.

Transesophageal echocardiography: technique, anatomic correlations, implementation, and clinical applications

The introduction of transesophageal echocardiography has provided a new acoustic window to the heart and mediastinum. High-quality images of certain cardiovascular structures [left atrial appendage, thoracic aorta, mitral valvular apparatus, and atrial septum] can be obtained readily (average examination, 15 to 20 minutes). In this article, we discuss the technique of image acquisition, image orientation, and anatomic validation. In addition, we describe our experience with the first 100 awake patients who underwent transesophageal echocardiography at our institution. The procedure was well accepted by the patients and associated with no major complications. The clinical indications for this procedure have included thoracic aortic dissection, prosthetic cardiac valve dysfunction, detection of an intracardiac source of embolism, endocarditis, cardiac and paracardiac masses, and mitral regurgitation. Transesophageal echocardiography also proved to be useful in assessment of critically ill patients in whom standard transthoracic echocardiographic images did not provide complete assessment. In these patients (who had extensive chest trauma, had undergone an operation, or were in an intensive-care unit), rapid assessment of the cardiovascular status at the bedside was possible with transesophageal echocardiography. On the basis of our initial experience, we conclude that transesophageal echocardiography complements standard two-dimensional Doppler and color flow examinations and will considerably improve the care of patients with cardiovascular disorders by providing high-quality unique images.