Intraoperative Echocardiography Research Articles

Confirmation of correct placement of the endocardial lead in cardiodefibrillator implantation by intraoperative transesophageal echocardiography.

Correct positioning of the endocardial lead in the apex of the right ventricle during the insertion of an implantable cardiodefibrillator (ICD) under general anesthesia, when cardiac function is generally poor, is most important. We describe herein a method of using intraoperative esophageal echocardiography in combination with fluoroscopy to confirm fixation of the endocardial ICD lead in the right ventricular apex.

Con: Pediatric anesthesiologists should not be the primary echocardiographers for pediatric patients undergoing cardiac surgical procedures

TRANSESOPHAGEAL ECHOCARDIOGRAPHY (TEE) was first introduced in 1976 and appeared in pediatric use in 1989. 1 Frazin L Talano JV Stephanides L et al. Esophageal echocardiography. Circulation. 1976; 54: 102-108 Crossref PubMed Scopus (243) Google Scholar , 2 Ritter S Hillel Z Narang J Transesophageal real-time Doppler flow imaging in congenital heart disease: Experience with a new pediatric transducer probe. Dynamic Cardiovasc Imaging. 1989; 2: 92-96 Google Scholar , 3 Ritter S Thys D Pediatric transesophageal color flow-imaging: Smaller probes for smaller hearts. Echocardiography. 1989; 6: 431-440 Crossref Scopus (42) Google Scholar Although its initial application in the assessment of congenital heart disease (CHD) was limited by probe size, the miniaturization of probes and development of multiplanar imaging greatly increased its role. 4 Stumper OF Elzenga NJ Hess J Sutherland GR Transesophageal echocardiography in children with congenital heart disease: An initial experience. J Am Coll Cardiol. 1990; 16: 433-441 Abstract Full Text PDF PubMed Scopus (93) Google Scholar , 5 Muhiudeen IA Roberson DA Silverman NH et al. Intraoperative echocardiography in infants and children with congenital cardiac shunt lesions: Transesophageal versus epicardial echocardiography. J Am Coll Cardiol. 1990; 16: 1687-1695 Abstract Full Text PDF PubMed Scopus (88) Google Scholar , 6 Lam J Neirotti R Nijveld A et al. Transesophageal echocardiography in pediatric patients: Preliminary results. J Am Soc Echocardiogr. 1991; 4: 43-50 Abstract Full Text PDF PubMed Scopus (27) Google Scholar , 7 Ritter SB Transesophageal echocardiography in children: New peephole to the heart. J Am Coll Cardiol. 1990; 16: 447-450 Abstract Full Text PDF PubMed Scopus (29) Google Scholar , 8 Seward J Khandheria B Freeman W et al. Multiplane transesophageal echocardiography: Image orientation, examination technique, anatomic correlations, and clinical applications. Mayo Clin Proc. 1993; 68: 523-551 Abstract Full Text Full Text PDF PubMed Scopus (192) Google Scholar At present, routine TEE can be safely performed in infants weighing ≥3 kg, and its use has been reported in infants weighing 2.4 kg. 9 Stevenson JG Sorensen GK Gartman DM et al. Transesophageal echocardiography during repair of congenital cardiac defects: Identification of residual problems necessitating reoperation. J Am Soc Echocardiogr. 1993; 6: 356-365 Abstract Full Text PDF PubMed Scopus (100) Google Scholar Excellent image quality and ability to examine the heart without disrupting the surgical field make TEE ideally suited for the intraoperative assessment of cardiac anatomy and physiology during cardiac surgery. This ease of use has led to the replacement of epicardial imaging by TEE.

Intraoperative contrast echocardiography with intravenousOptison does not cause hemodynamic changes during cardiac surgery

Background: The echocardiographic contrast agent Optison may be useful in patients undergoing cardiac surgery. This study investigates its effects on hemodynamics, cardiac performance, and oxygenation in this group of patients. Methods: Parameters of hemodynamic stability, cardiac performance, and oxygenation were measured in 57 patients by transesophageal echocardiography, electrocardiography, invasive arterial blood pressure and central venous pressure monitoring, capnography, pulsoximetry, and pulmonary artery catheter before and 5 and 10 minutes after an intravenous bolus of 0.3 mL of Optison. Results: No statistically significant differences in ST-segment changes, heart rate, arterial and central venous pressure, peripheral oxygen saturation, cardiac index, left ventricular ejection fraction, and regional wall motion were seen 5 and 10 minutes after injection of Optison compared with baseline parameters. Conclusions: Optison did not cause clinically important changes in parameters of hemodynamic stability, cardiac performance, and oxygenation in our patients. The intraoperative use of intravenous Optison appears to be safe in patients undergoing cardiac surgery, including in the use of cardiopulmonary bypass. (J Am Soc Echocardiogr 2001;14:595-600.)

Mitral valve replacement with homograft

The purpose of this study was to review the results of mitral valve replacement with mitral valve homograft, applying the method described by Acar, to determine if the method could be reproduced and was safe to use. Fourteen patients had replacement of the mitral valve with homograft. The diseased valve was excised and replaced with a cryopreserved homograft. The papillary muscles of the graft were attached to the papillary muscles of the patient in side-to-side fashion, using multiple stitches of fine monofilament suture. The annulus of the graft was attached to the patient annulus by continuous suture. The repair was supported by annuloplasty ring. All patients had intraoperative echocardiography. Patients were monitored clinically for up to 1.5 years. There were five men and nine women ranging in age from 16 to 70 years (mean = 43 years). Seven had rheumatic, six had degenerative, and one congenital morphology. Concomitant Maze III procedure was performed in three patients. All patients survived and are currently alive and in New York Heart Association functional class I. Thirteen patients have normal sinus rhythm. Only one patient has intermittent atrial fibrillation and is taking digoxin and warfarin. One patient had dehiscence of the recipient papillary muscle that required reoperation for mitral valve replacement with prosthesis. Three patients have moderate mitral valve regurgitation. Mitral valve replacement with homograft may be accomplished safely and reproducibly using the Acar method. Good short-term functional results and maintenance of normal sinus rhythm may be expected. Anticoagulant therapy should not be required.

Intraoperative Echocardiography in Pediatric Heart Disease

Intraoperative echocardiography has become an invaluable diagnostic and monitoring technique in surgery for pediatric heart disease. Transesophageal echocardiography (TEE) has largely replaced epicardial echocardiography as the pre ferred approach. TEE has the advantage of allowing serial assessment of anatomy and function with no interruption of surgery. Recent advances in transducer technology of the TEE probe and the introduction of novel modes of imaging have greatly increased the applicability of TEE in pediatric congenital cardiac repair. TEE has been used for a spectrum of congenital lesions such as valve anomalies, shunts, ob structions, and complex heart defects, as well as to monitor for myocardial ischemia and left ventricular preload. Expe rience and evidence suggest that intraoperative TEE can improve clinical outcomes in children undergoing repair of congenital cardiac defects. The safety and efficacy of TEE in children have been well established. This article outlines the development of intraoperative echocardiography and dis cusses TEE as a diagnostic tool in the management of pedi atric heart disease.

Changes in regional myocardial function after coronary artery bypass graft surgery are predicted by intraoperative low-dose dobutamine echocardiography.

Left ventricular dysfunction is often reversed after coronary artery bypass graft (CABG) surgery; however, this change is not easily predicted. The authors hypothesized that functional changes after a low dose of dobutamine (5 microgram. kg-1. min-1) intraoperatively would predict functional changes when complete revascularization was achieved. The authors analyzed 560 segments in 40 patients scheduled for elective CABG surgery for regional wall motion (1-5 scoring system) at four stages: baseline (after induction and intubation), with administration of low-dose dobutamine before cardiopulmonary bypass, after separation from cardiopulmonary bypass (early), and after administration of protamine (late). Two independent observers scored the myocardial regions according to a 16-segment model in multiple imaging planes. For each segment, the response to dobutamine was dichotomized as improved or not improved from baseline and analyzed with logistic regression. The influence of covariates (ejection fraction, myocardial infarction, diabetes mellitus, and beta blockers) was also determined with logistic regression models. P < 0.05 was considered significant. Changes in myocardial function after low-dose dobutamine were highly predictive for early (P < 0.0001) and late (P < 0.0001) changes in myocardial function from baseline regional scores. The overall odds ratio for early and late improvement increased by 20.7 and 34.6, respectively, when improvement was observed after low-dose dobutamine was administered. The overall positive predictive value of improved regional wall motion after CABG did not vary with left ventricular ejection fraction, a history of myocardial infarction, or beta blocker use, and it varied little with diabetic status (range, 0.86-0.96) if regional wall motion improved with low-dose dobutamine before CABG. The overall negative predictive value was 0.70; however, the range varied with diabetic status (i.e., lowest in diabetic patients and highest in nondiabetic patients). Intraoperative low-dose dobutamine is a reliable method to predict myocardial functional reserve and to determine functional recovery expected after coronary revascularization.

Room 302, 10/18/2000 2: 00 PM - 3: 30 PM (PD) Reproducibility of Regional Wall Motion Analysis during Intraoperative Low Dose Dobutamine Stress Echocardiography (DSE) in CABG Surgery

<b>Room 302, 10/18/2000 2: 00 PM - 3: 30 PM (PD) Reproducibility of Regional Wall Motion Analysis during Intraoperative Low Dose Dobutamine Stress Echocardiography (DSE) in CABG Surgery</b>

Real-time intraoperative monitoring of myocardial ischemia in noncardiac surgery.

Real-time intraoperative monitoring of myocardial ischemia in noncardiac surgery.

PROGRESS IN THE DEVELOPMENT OF A TRILEAFLET MECHANICAL HEART VALVE (MHV)

Progress continues in the development of a trileaflet MHV (Triflo Medical, Inc., Costa Mesa, CA) that does not necessitate anticoagulation therapy. Three versions have been studied in calves: a prototype with delrin leaflets, a similar model, the T1 with pyrolytic carbon leaflets and reduced swing angle from 60° to 50° and the final version, the T2. The T2 was redesigned using flow visualization and computational fluid dynamic (CFD) analysis, in an effort to optimize the valve's hemodynamic characteristics, minimize thrombogenicity and duplicate physiologic valve closing characteristics. All versions have undergone extensive in vitro testing at the Helmholtz Institute, Aachen, Germany. A brief review of design changes and in vitro testing is presented along with the results of ongoing in vivo studies testing versions T1 and T2. In a recently completed study, 14 calves (80 to 100kgs) each received a 29mm T1 valve in the mitral position. Five experiments were ended early because of surgical complications. The intended study duration was 3 months, but 1 experiment was continued for 502 days to investigate the feasibility of in vivo leaflet wear testing. In an ongoing study involving the same calf model, seven model T2 MHVs are being tested in experiments, designed to last 5 to 6 months. Four of these experiments have been completed, 1 of which was terminated at 104 days because of infection. The other 3 are ongoing. In all full-term studies, valve performance was excellent, as evidenced by satisfactory intra-operative echocardiography findings, normal weight gain, activity and good health. In each case, I.V. heparin therapy (100mg/day) was discontinued after 10 days. Hematologically, the full-term calves remained within normal limits. At the end of the experiments, left heart catheterization showed a mean transvalvular pressure gradient of 10.52±2.21 mmHg and insignificant valvular regurgitation at heart rates from 50 to 190 bpm and cardiac outputs from 4 to 20 L/min. Gross examination of explanted valves showed no thrombus deposits. Histopathologic examination of major organs showed no evidence of thromboembolic events. Both the T1 and T2 valves performed well without long-term anticoagulation in the calf MVR model.

Partial left ventriculectomy, ventriculoplasty or valvular surgery for idiopathic dilated cardiomyopathy - the role of intra-operative echocardiography.

The partial left ventriculectomy (PLV) is known to work in some patients with dilated cardiomyopathy (DCM), although this procedure does not work well in all patients and the operative mortality is higher than the other cardiac surgeries. In addition to PLV, left ventriculoplasty to exclude antero-septal wall or valvular surgery without left ventricle (LV) surgery can be also effective in patients with DCM. To improve the surgical results for dilated cardiomyopathy, we introduced echo-guided volume reduction test and evaluated the surgical procedures and the results on the surgery for DCM. Between December 1996 and July 1999, 56 patients with DCM (50 with idiopathic DCM, six with dilated hypertrophic cardiomyopathy) were surgically treated. Under the standard cardiopulmonary bypass, left ventricular motion was determined with color kinesis of echocardiogram and the lesion of akinetic wall was removed or excluded. After the initial PLV in 18 patients (initial group), operative procedures were selected in 21 with PLV, five with LV plasty, or 12 with valve surgery without LV surgery according to the findings of the LV wall motion by intraoperative echogram (select group). There were six hospital deaths and late follow-up deaths within 1 year in initial group, however, the mortality decreased significantly after the selection of the operative procedures; three hospital deaths and two late deaths in the select-group (P<0.05). Significant decrease of left ventricular diameter, the LV ejection fraction and endosystolic volume index were demonstrated after the LV surgery. The survival rate improved significantly after the selection of the operative procedures; 14 months survival rates was 50.0% in initial group and 73.1% in select group (P<0.05). Operative mortality decreased and late follow-up results improved after the selection of operative procedures according to the intraoperative volume reduction test.

Intraoperative Echocardiography

Intraoperative Echocardiography

Development and Costs of an Intraoperative Echocardiography Service

Intraoperative echocardiography (IOE) has become an important part of cardiovascular anesthesiology. An IOE service should provide the equipment and personnel needed to acquire and interpret echocardiographic images during surgery and communicate findings to the medical record. It also should archive images and reports, provide training in echocardiography skills, arrange for continuous quality improvement, and develop a means to bill for echocardiography services. Although the costs of providing IOE services can be estimated, the financial impact of starting such a service will vary greatly between institutions depending on the availability and use of existing resources and expertise. IOE is not a trivial skill and requires considerable training and experience to perform competently. Reimbursement for IOE services provided by anesthesiologists is highly dependent on local policies and will require continued vigilance and effort to be made fair and reasonable for all providers. The primary motivation for anesthesiologists to become involved in IOE is improved patient care.

Significant intraoperative right ventricular outflow gradients after repair for tetralogy of Fallot: to revise or not to revise?

Background. This study was performed to define alternative parameters for the management of intraoperative residual right ventricular outflow obstruction (RVOTO) after transatrial repair of tetralogy of Fallot (ToF) in order to differentiate those requiring immediate revision from those who do not.Methods. Since October 1995, 166 patients of ToF underwent transatrial repair. Postbypass residual RVOTO was assessed by surgeon’s subjective impression, direct intracardiac pressure measurements, and intraoperative echocardiography (IOE). RVOTO was labeled “significant” whenever it exceeded a gradient of 40 mm Hg on IOE or right ventricular to left ventricular pressure ratio (pRV/LV) exceeded 0.85. Further, on IOE, significant RVOTO was defined “fixed”, if there was no change in RVOT dimensions during the cardiac cycle, along with the presence of anatomic substrate for obstruction, and “dynamic” if RVOT dimensions increased appreciably in diastole. Postoperative course and follow-up echocardiograms of all patients were analyzed.Results. Significant RVOTO was detected in 58 (35%) patients (mean gradient 54 mm Hg). Seven (12%) of them with fixed obstruction (mean 46 mm Hg) underwent immediate surgical revision, while the remaining 51 patients with mean gradient of 78 mm Hg (including 10 patients with pRV/LV ratio of ≥1.0) with dynamic obstruction did not undergo revision. There were six (3.6%) early deaths. Operative mortality and postoperative morbidity were not related to higher residual gradients, although the first 15 such patients had longer intensive care stay and inotropic support, in which this was done electively. On follow-up (mean 18.5 months), outflow gradients declined sharply (mean 16 mm Hg) irrespective of the severity of intraoperative gradients (p < 0.001). There were no reoperations or late deaths.Conclusions. This study shows that: 1) existing parameters for immediate revision of residual RVOTO possibly need to be reviewed; 2) intraoperative echocardiography helps in differentiating “fixed” from “dynamic” obstruction and helps obviate needless revisions; and 3) dynamic RVOT gradients decline significantly irrespective of their severity after transatrial repair of ToF.

A clinical dilemma: cardiac and pericardiac echinococcosis

Background. Cardiac and pericardial echinococcosis as a life-threatening disease may present with a clear picture most of the time, however it may also become a clinical puzzle. Methods. In the period between 1977 and 1998, 14 patients were operated on with the diagnosis of cardiac and pericardial echinococcosis. Nine patients were operated on with standard cardiopulmonary bypass (CPB) techniques, and the remaining 5 patients were operated on without CPB. Transesophageal echocardiography (TEE) or intraoperative surface echocardiography were used to plan and perform the operation for the late cases. Results. One patient died during the postoperative period due to the rupture of interventricular septum. All other patients survived the perioperative period, received mebendazole treatment, and exhibited no recurrence during the follow-up. Conclusions. The definitive treatment is the surgical extraction of the cyst. Because the clinical picture may vary according to the number, size, and location of cysts, as well as complications, cardiac echinococcosis should be remembered and included in the differential diagnosis to achieve the treatment. Intraoperative surface echocardiography is of paramount value for diagnosis and planning the management of a successful surgery.

ASE/SCA Guidelines for Performing a Comprehensive Intraoperative Multiplane Transesophageal Echocardiography Examination: Recommendations of the American Society of Echocardiography Council for Intraoperative Echocardiography and the Society of Cardiovascular Anesthesiologists Task Force for Certification in Perioperative Transesophageal Echocardiography

Since the introduction of transesophageal echocardiography (TEE) to the operating room in the early 1980s,1-4 its effectiveness as a clinical monitor to assist in the hemodynamic management of patients during general anesthesia and its reliability to make intraoperative diagnoses during cardiac operations has been well established.5-26 In recognition of the increasing clinical applications and use of intraoperative TEE, the American Society of Echocardiography (ASE) established the Council for Intraoperative Echocardiography in 1993 to address issues related to the use of echocardiography in the operating room. In June 1997, the Council board decided to create a set of guidelines for performing a comprehensive TEE examination composed of a set of anatomically directed cross-sectional views. The Society of Cardiovascular Anesthesiologists Task Force for Certification in Perioperative Transesophageal Echocardiography has endorsed these guidelines and standards of nomenclature for the various anatomically directed cross-sectional views of the comprehensive TEE examination. This document, therefore, is the collective result of an effort that represents the consensus view of both anesthesiologists and cardiologists who have extensive experience in intraoperative echocardiography. The writing group has several goals in mind in creating these guidelines. The first is to facilitate training in intraoperative TEE by providing a framework in which to develop the necessary knowledge and skills. The guidelines may also enhance quality improvement by providing a means to assess the technical quality and completeness of individual studies. More consistent acquisition and description of intraoperative echocardiographic data will facilitate communication between centers and provide a basis for multicenter investigations. In recognition of the increasing availability and advantages of digital image storage, the guidelines define a set of cross-sectional views and nomenclature that constitute a comprehensive intraoperative TEE examination that could be stored in a digital format. These guidelines will encourage industry to develop echocardiography systems that allow quick and easy acquisition, labeling, and storage of images in the operating room, as well as a simple mechanism for side-by-side comparison of views made at different times. ASE/SCA Guidelines for Performing a Comprehensive Intraoperative Multiplane Transesophageal Echocardiography Examination: Recommendations of the American Society of Echocardiography Council for Intraoperative Echocardiography and the Society of Cardiovascular Anesthesiologists Task Force for Certification in Perioperative Transesophageal Echocardiography

Aortic Stenosis: The Role of Transesophageal Echocardiography.

Noninvasive assessment of aortic valve area by echocardiography has become the standard of practice over the past few years. The advent of transesophageal echocardiography (TEE) has provided a new method for the assessment of aortic valve area (AVA) using planimetry by two-dimensional imaging. Clear visualization of the anatomy of the valve, as well as accuracy of AVA assessment, makes TEE an invaluable tool for the evaluation of aortic valve stenosis. TEE is especially helpful in clinical settings when there is a discrepancy between the AVA obtained by transthoracic echocardiography and cardiac catheterization. TEE is particularly helpful in the assessment of the aortic valve during intraoperative echocardiography. This review discusses the techniques, imaging planes, and details for assessing AVA by TEE. The role of TEE in AVA assessment is described, with specific clinical case examples cited.

ASE/SCA Guidelines for Performing a Comprehensive Intraoperative Multiplane Transesophageal Echocardiography Examination: Recommendations of the American Society of Echocardiography Council for Intraoperative Echocardiography and the Society of Cardiovascular Anesthesiologists Task Force for Certification in Perioperative Transesophageal Echocardiography

ASE/SCA Guidelines for Performing a Comprehensive Intraoperative Multiplane Transesophageal Echocardiography Examination: Recommendations of the American Society of Echocardiography Council for Intraoperative Echocardiography and the Society of Cardiovascular Anesthesiologists Task Force for Certification in Perioperative Transesophageal Echocardiography

Intraoperative transesophageal echocardiography: correlation of echocardiographic findings and surgical pathology.

Before the introduction of transesophageal echocardiography (TEE) in the operating room, intraoperative echocardiography relied on epicardial imaging. The disadvantages of this approach included interference with the surgical procedure, limited windows, and potential distortion of cardiac structures. Consequently, multiplane TEE has now emerged as the intraoperative imaging method of choice. It provides high-resolution images of cardiac structures and excellent portraits of flow abnormalities. Intraoperative TEE does not interfere with the surgical field and procedure. TEE provides better imaging of the valves, atria, aorta, pulmonic vasculature, and pericardium, which are sometimes difficult to visualize by transthoracic echocardiography. TEE is especially beneficial in surgeries for valve replacement, valve repair, cardiac mass, aortic disease, congenital heart disease, and pericardial disease. Presurgical TEE provides information for surgical planning. TEE is helpful for the assessment of the immediate result of surgery and detection of complications that may need a prompt response. Thus, intraoperative TEE has a vital impact on management of cardiac surgery.

Echocardiography in Minimally Invasive Direct Coronary Artery Bypass.

Minimally invasive direct coronary artery bypass (MIDCAB) is a recently developed, less-invasive alternative to standard bypass surgery. MIDCAB is performed through a small incision (2-3 inches) on the beating heart without the use of cardiopulmonary bypass or cardioplegia. It is associated with less trauma and a shorter hospital stay than conventional surgery. Transesophageal echocardiography helps in patient selection by detecting protruding aortic atheromas (PATHs), which are associated with a high risk of stroke during typical cardiopulmonary bypass. MIDCAB may be the technique of choice in patients with PATHs. Intraoperative echocardiography can detect wall motion abnormalities and helps in determining intraoperative myocardial ischemia and the postoperative prognosis. Duplex study of the internal mammary arteries is helpful in evaluating coronary anastomosis patency. Characteristically, a patent coronary anastomosis demonstrates a high diastolic flow fraction, with a ratio between peak diastolic and peak systolic flow velocity of > 1.

Intraoperative Echocardiography for the Patient Undergoing Minimally Invasive Heart Surgery

Minimally invasive heart surgeries are commonly used to avoid large surgical incisions and facilitate early extubation and recovery after cardiac surgeries. Trans esophageal echocardiography (TEE) is especially valu able in minimally invasive cardiac surgery because the inherently limited access to the thorax and mediasti num impairs direct visualization of the heart. TEE influ ences the clinical decision making process in several ways. Changes to the anesthetic management include alteration in volume loading in the presence of diastolic dysfunction or left ventricular outflow tract obstruction, as well as augmenting coronary perfusion pressure and implementing coronary vasodilators for new regional wall motion abnormalities. Changes to the surgical plans include replacement or repair for regurgitant valves, placement of intra-aortic balloon pumps for persistent regional wall motion abnormalities, and changing the surgical approach in the presence of severe aortic disease. Currently, two approaches are commonly used in minimally invasive cardiac surgery. The first approach, port-access minimally invasive car diac surgery, continues to use cardiopulmonary bypass. This approach relies extensively on TEE to correctly place endovascular devices necessary for cardiopulmo nary bypass in addition to routine assessment of car diac function. The second approach, minimally invasive direct coronary artery bypass, involves performing the revascularization on a beating heart. Here, TEE is essen tial for assessment of ventricular function if ischemic preconditioning is used as a strategy for myocardial protection.