Transesophageal Echo Probe Research Articles

Abstract 15091: Cardiac Ct-Guided Exclusion of Left Atrial Appendage Thrombus Prior to Electrical Cardioversion for Atrial Fibrillation

Introduction: Transesophageal echo (TEE) is routinely used to exclude left atrial appendage (LAA) thrombus prior to direct current cardioversion (DCCV) for atrial fibrillation (AF). However, the COVID-19 pandemic accelerated the use of non-invasive modalities such as cardiac computed tomography (CCT) to avoid aerosolizing viral particles during intubation, such as with introduction of a TEE probe. CCT is not routinely used as a clinical strategy to exclude LAA thrombus prior to DCCV. Therefore, we sought to determine the feasibility of CCT-guided DCCV.Hypothesis: CCT-guided elective cardioversion for atrial arrhythmias is a feasible modality to rule out left atrial appendage thrombus. Methods: We identified patients at Abbott Northwestern Hospital who underwent CCT in lieu of or in addition to TEE within 24 hours of elective DCCV for AF or atrial flutter from March 2020 to February 2022. Thirty-day outcomes were collected including cerebrovascular accident (CVA), myocardial infarction, cardiovascular death, re-hospitalization, arrhythmia recurrence, and overall mortality. Delayed imaging, 90 seconds after arterial phase, was obtained to exclude LAA thrombus. Results: Thirty-two patients were included in our analysis, 10 (31%) were female. Ten (31%) presented with new-onset of AF. CCT did not identify LAA thrombus in any patient. Post-DCCV, the mean time to arrhythmia recurrence was 16.5 days (SD: 9.3). At 30 days, 11 (34%) had been re-hospitalized but mostly for elective procedures. There was no CVA or mortality reported at the 30-day follow-up. Conclusion: CCT-guided elective cardioversion for atrial arrhythmias was evaluated for feasibility in a small pilot. In patients who had no LAA thrombus on CCT and subsequently underwent cardioversion, there were no CCT-related complications, CVA, or deaths at 30 days. Many patients benefit from early DCCV rather than waiting with uninterrupted anticoagulation. CCT guidance is a feasible alternative to TEE but needs further prospective comparison to TEE and uninterrupted anticoagulation in this clinical setting.

New oropharyngeal double lumen cannula for sedation for transesophageal echocardiography: case series

IntroductionCurrently, transesophageal echodopplercardiography is frequently performed under sedation on an outpatient basis. Sedation is related with increase in incidents on airways. Bearing in mind this scenario, we developed a new double lumen oropharyngeal cannula aimed at keeping airway patency, in addition to reducing risks to patients during endoscopy procedures performed under sedation. The main objective of our study was to assess the incidence of oxygen desaturation in a series of cases of adult patients submitted to outpatient transesophageal echo exam, under sedation and using the oropharyngeal cannula. Method30 patients under sedation with intravenous midazolam and propofol were assessed. After loss of consciousness, the cannula was placed and patients were maintained on spontaneous breathing. Oxygen saturation, capnometry, heart rate and non-invasive arterial blood pressure, in addition to subjective data: airway patency, handling of cannula insertion and, comfort of examiner were analyzed. ResultsThe incidence of mild desaturation was 23.3%, and there was no severe desaturation in any of the cases. The insertion of the oropharyngeal cannula was considered easy for 29 patients (96.6%), and transesophageal echo probe handling was appropriate in 93.33% of exams performed. ConclusionsTransesophageal echo exams under sedation aided by the double-lumen oropharyngeal cannula presented a low incidence of desaturation in patients assessed, and allowed analysis of expired CO2 during the exams.

Does the endotracheal tube cuff pressure increases with transesophageal probe insertion?

Context:The cuff pressure (CP) of the endotracheal tube (ETT) exceeding 30 cm of H2O results in reduced perfusion of lateral mucosa of trachea leading to complications. As the posterior tracheal wall is in contact with the esophagus, there is a possibility that the insertion of transesophageal echo (TEE) probe may compress the tracheal wall and increase CP.Aims:This study was aimed to assess the impact of TEE probe insertion on CP in adults undergoing cardiac surgery.Settings and Design:Prospective observational study of 65 patients at tertiary care level hospital.Subjects and Methods:After balanced general anesthesia, patients were intubated with high volume low-pressure ET.TEE probe was then inserted with gentle jaw thrust. CP was measured by standard invasive pressure monitoring device at four points: T1 at baseline before TEE probe insertion; T2 maximum CP noted at TEE probe insertion; T3 at 5 min post TEE probe insertion; and T4 at post-TEE exam.Statistical Analysis Used:CP was compared between pairs of time points (T1 vs. T2; T1 vs. T3; and T1 vs. T4) using Mann-Whitney U test. Factors predicting CP >30 cm of H2O at T4 were assessed by backward stepwise regression.Results:CP (mean ± S.D.) at T1, T2, T3, and T4 was 22 ± 3, 38 ± 10, 30 ± 6, and 30 ± 7, respectively. CP increased significantly from T1 to T2 (P < 0.001), T1 to T3 (P < 0.001), and T1 to T4 (P < 0.001). There were 26 patients (40%) with CP >30 cm of H2O at end of TEE exam (T4). On multivariate analysis baseline, CP (T1) >20 cm of H2O was significantly associated with CP >30 cm of H2O at end of TEE exam with Odd's Ratio (OR) of 8.5 (1.76–41.06, P = 0.008).Conclusions:To conclude, the CP increases significantly with TEE probe insertion in 40% of patients exceeding a safe limit of 30 cm of H2O. The monitoring and optimization of CP is advisable.

The Transesophageal Echo Probe May Contribute to Esophageal Injury After Catheter Ablation for Paroxysmal Atrial Fibrillation Under General Anesthesia: A Preliminary Observation

The transesophageal echo probe (TEE) is commonly used before and during atrial fibrillation (AF) ablation under general anesthesia (GA). We sought to determine the potential contribution of the TEE probe to esophageal injury after pulmonary vein isolation (PVI) alone for paroxysmal AF. Seventy-six patients undergoing PVI with TEE, PVI/TEE, 16 undergoing PVI without TEE (PVI/No TEE), and 27 undergoing TEE without any left atrial ablation (TEE/No LA ablation) under GA were included. Posterior wall ablation was power (20-25 W) and time limited (electrogram attenuation or ≤30 s). Esophageal capsule endoscopy (n = 206) was performed pre- and post-procedure and at 2 weeks. Esophageal lesions were seen in 30% of PVI/TEE, 0% of patients in the PVI/No TEE (P = 0.009), and 22% of TEE/No LA ablation groups (P = 0.47 vs. PVI/TEE). There were no instances of esophageal bleeding, perforation, or need for gastrointestinal intervention. Self-resolving dysphagia was the only reported symptom (5%). All lesions healed within 2 weeks. There was no significant difference in the location or morphological appearance of esophageal lesions seen in the PVI/TEE versus TEE/No LA ablation groups. Esophageal lesions were seen in 30% of patients undergoing PVI alone under GA with use of TEE and in a similar proportion (22%) of patients undergoing TEE in the absence of left atrial ablation. This study makes the preliminary observation that one must be cognizant of the TEE probe as a potential contributor to esophageal injury after AF ablation. Larger studies are needed to confirm these findings.

Dislocation of the temporomandibular joint following general anesthesia.

Anesthesiologists are often concerned with the immobile temporomandibular joint (TMJ), but are sometimes faced with hypermobility and subluxation of the TMJ. Such TMJ instability has a prevalence of up to 25-50% in the general population, and is most common in middle-aged females [1]. TMJ dislocation that occurs during operations is often unnoticed until patients become aware of pain and swelling. Unrecognized TMJ displacement can lead to chronic pain and restricted joint mobility [2]. We report here two patients who had TMJ dislocation; one was observed in the post-anesthetic care unit (PACU) and the other in the operation room before transfer to the PACU. A 34-year-old man weighing 78 kg was scheduled to undergo laparoscopic appendectomy. General anesthesia was conducted uneventfully and the duration of anesthesia was 1 hour. During the following 30 minutes in the PACU, a nurse noticed that the patient's mouth remained wide open. The patient complained of pain over the left parotid region, and mentioned he had experienced TMJ dislocation before. The diagnosis of anterior left TMJ dislocation was made and a manual reduction of TMJ was easily performed by a dentist. An 18-year-old woman weighing 79 kg underwent tonsillectomy; she did not have a history of prior TMJ dysfunction. General anesthesia was done uneventfully and the duration of anesthesia was 90 minutes. When oropharynx was suctioned prior to extubation, the patient's mouth was widely opened and remained open. Diagnosis of dislocation of the mandible was confirmed and immediately corrected by the dentist. TMJ dislocation is the dislodgement of the condyle from its normal position in the squamo-temporal portion of the cranial base [2,3]. It could occur spontaneously or by trauma, endotracheal intubation, LMA insert, ENT/dental procedures, endoscopy, yawning, laughing, vomiting, transesophageal echo probe placement, seizure, congenital anomaly and medication [4]. Acute TMJ dislocation is associated with pain and severe tenderness over the TMJ areas. If left untreated for longer than 14 days, fibrosis and even fractures become increasingly apparent, which may require surgical treatment [3,4]. TMJ disorders can affect airway management during surgery. If the patient has a history of TMJ dislocation, we should take more caution during airway management. We should also provide information regarding the possibility of postoperative TMJ dislocation, because patients cannot comprehend a TMJ dislocation at a non-face surgery. Argo et al. [5] reported increased symptoms following endotracheal intubation in 44% of patients with preexisting TMJ dysfunction. At the recovery period, we should be concerned about patients who complain pain around the TMJ area, particularly patients with a history of TMJ disorders and who cannot speak well. If the patient is unconscious or unable to respond, a physical examination by checking the range of motion of the TMJ would help [2,4]. In conclusion, TMJ dislocation is a common side effect of airway manipulation, particularly in a sedated or anesthetized patient. However, its diagnosis can easily be overlooked. For prevention, manipulation involving the upper airway should be firm but gentle. Also, early recognition and treatment of TMJ dislocation would reduce the incidence of long-term complications.

Management of upper aerodigestive tract bleeding on extracorporeal membrane oxygenation

Introduction: Bleeding complications are often encountered on extracorporeal membrane oxygenation (ECMO). In a review of our own series, it was found that upper aero digestive tract bleeding was common and that its management was often difficult. We propose an algorithm to help manage upper aerodigestive tract bleeding in the anticoagulated, ECMO patient. Methods: A retrospective chart review was performed of the patients who underwent veno-venous or venoarterial ECMO at our institution between July 2010 and July 2012. The patients that had upper aerodigestive tract bleeding that required an otolaryngology consultation were identified. They were further investigated to determine the location of bleed, and procedures were performed to control the bleeding. Results: Among the 37 consecutive patients on ECMO, 11 (30%) had upper aerodigestive tract bleeding events. Of these 11, 7 (63.6%) were secondary to an iatrogenic incident, such as placing a nasogastric tube or transesophageal echo probe. All 11 patients were treated at bedside with conservative management and 3 were treated in the operating room. Four patients (36%) treated with conservative management required repeated procedures due to incomplete hemostasis, compared to no repeated procedure required once surgical intervention in the operating room was complete. Conclusion: Approximately one-third of the ECMO patients developed upper aerodigestive tract bleeding. This bleeding should be controlled in a timely manner; otherwise it may result in massive transfusions. Delaying intervention or conservative management may not be effective. We recommend surgical intervention, if the initial conservative management failed and continued to bleed for more than 24-36 hours. Keywords: ECMO; upper aerodigestive tract; bleeding; anticoagulation; management (Published: 8 February 2013) Citation: Mechanical Circulatory Support 2013, 4 : 20333 - http://dx.doi.org/10.3402/mcs.v4i0.20333

US–Fluoroscopy Registration for Transcatheter Aortic Valve Implantation

Transcatheter aortic valve implantation is a minimally invasive alternative to open-heart surgery for aortic stenosis in which a stent-based bioprosthetic valve is delivered into the heart on a catheter. Limited visualization during this procedure can lead to severe complications. Improved visualization can be provided by live registration of transesophageal echo (TEE) and fluoroscopy images intraoperatively. Since the TEE probe is always visible in the fluoroscopy image, it is possible to track it using fiducial-based single-perspective pose estimation. In this study, inherent probe tracking performance was assessed, and TEE to fluoroscopy registration accuracy and robustness were evaluated. Results demonstrated probe tracking errors of below 0.6 mm and 0.2°, a 2-D RMS registration error of 1.5 mm, and a tracking failure rate of below 1%. In addition to providing live registration and better accuracy and robustness compared to existing TEE probe tracking methods, this system is designed to be suitable for clinical use. It is fully automatic, requires no additional operating room hardware, does not require intraoperative calibration, maintains existing procedure and imaging workflow without modification, and can be implemented in all cardiac centers at extremely low cost.

Annuloaortic ectasia treated successfully in a pregnant woman with Marfan syndrome: report of a case

A 31-year-old woman with Marfan syndrome required aortic root repair for annuloaortic ectasia in the 16th week of her first pregnancy. Aortic root reimplantation was successfully performed with a higher-flow-rate cardiopulmonary bypass of 3.4-3.6 l/min/m2 at normothermia for fetal survival. During the surgery, a cardiotocography and transesophageal echo probe attached on the patient's abdomen allowed adequate monitoring of the fetal heartbeat. The postoperative course was uneventful, and a healthy baby was delivered by cesarean section at 37 weeks' gestation.

Dynamic and volumetric variables of fluid responsiveness fail during immediate postresuscitation period*

Fluid therapy after resuscitation from cardiac arrest is challenging since both hypovolemia and fluid overload may cause circulatory failure. Therefore, prediction of fluid responsiveness is a major issue in optimizing hemodynamic therapy. The aim of the present study was to evaluate the performance of stroke volume variation, pulse pressure variation, variation of Doppler-derived velocity time integral, and global end-diastolic volume index to predict fluid responsiveness in the postcardiac arrest period. Prospective animal study. University-affiliated research laboratory. Twenty anesthetized and ventilated Goettinger minipigs. Animals were equipped with a central venous catheter, a thermistor-tipped arterial catheter, and a transesophageal echo probe. Electrically induced cardiac arrest of 8 mins was followed by cardiopulmonary resuscitation. Hemodynamic measurements were performed before and after a two-step fluid bolus at baseline and both 1 and 4 hrs after return of spontaneous circulation. Fluid responsiveness was defined by an increase in stroke volume of at least 15%. Performance of variables was analyzed using receiver operator characteristics analysis. Variables reliably indicated fluid responsiveness at baseline. Fifteen animals were successfully resuscitated. Left ventricular ejection fraction was significantly reduced 1 hr after return of spontaneous circulation (52.6% ± 6.4%; p < .01) compared with baseline (69.9% ± 5.3%). One hour after return of spontaneous circulation, fluid responsiveness could not be predicted by any variable. In contrast, pulse pressure variation, variation of the velocity time integral, and global end-diastolic volume index, but not stroke volume variation, were able to predict fluid responsiveness 4 hrs after return of spontaneous circulation, since area under the curve was 0.85 (p < .01), 0.94 (p < .01), 0.77 (p = .02), and 0.68 (p = .12), respectively. Prediction of fluid responsiveness failed 1 hr after successful cardiopulmonary resuscitation from cardiac arrest. Four hours after return of spontaneous circulation, however, the variables pulse pressure variation, variation of the velocity time integral, and global end-diastolic volume index, but not stroke volume variation, enabled prediction of fluid responsiveness and may, therefore, be considered for subsequent hemodynamic optimization after successful cardiopulmonary resuscitation.

Design of a Catheter-Based Device for Performing Percutaneous Chordal-Cutting Procedures

In this paper we detail the rapid design, fabrication and testing of a percutaneous catheterbased device that is envisioned to enable externally controlled manipulation and cutting of specific chordae tendinae within the heart. The importance of this work is that it (a) provides a means that surgeons may use to alleviate problems associated with some forms of mitral valve regurgitation and (b) demonstrates how a deterministic design process may be used to drive design innovation in medical devices while lowering development cost/time/resources. In the United States alone, approximately 500,000 people develop ischemic or functional MR per year. A chordal cutting procedure and device could allow many patients, who would otherwise be unable to survive open-heart surgery, to undergo a potentially life-saving operation at reduced risk. The design process has enabled us to generate a solution to this problem in a relatively short time. A deterministic design process was used to generate several design concepts and then evaluate and compare each concept based on a set of functional requirements. A final concept to be alpha prototyped was then chosen, optimized, and fabricated. The design process made it possible to make rapid progress during the project and to achieve a device design that worked the first time. This approach is important to medical device design as it reduces engineering effort, cost, and the amount of time spent in iterative design cycles. An overview of the design process will be presented and discussed within the context of a specific case study–the rapid design/fabrication of a chordal cutting device. Experimental results will be used to assess: (i) The performance of the catheter in maneuvering into the heart and grasping various structures. (ii) The effectiveness of the catheter's RF ablation tip at cutting chordae inside of a heart. In the first experiment, the catheter was guided to the basal chordae under direct visualization, which showed that the catheter is capable of successfully grasping a chord. During the second experiment, ultrasound was shown to be a viable method of visualizing the catheter within the heart. During this experiment, once contact between the chord and RF ablator tip was confirmed, the chord was successfully ablated. We will also discuss experiments that are currently underway to visualize the catheter utilizing a Trans-Esophageal Echo probe, as well as imaging the mitral valve from the apex of the heart with a laparoscope so that video of the basal chord being grasped and cut can be acquired on a heart whose anatomical structures are intact. A brief synopsis will then be given of how the design process has been used in research and educational collaborations between MIT and local hospitals.

Catheter closure of atrial septal defects with deficient inferior vena cava rim under transesophageal echo guidance

To describe the case selection, imaging considerations, technique, and results of catheter closure of atrial septal defects (ASD) with deficient inferior vena cava (IVC) rim. Transcatheter closure with Amplatzer septal occluder (ASO) has become standard treatment for most secundum ASDs. Defects with deficient IVC rim continue to be challenging to image and close in the catheterization laboratory. Records of 12 patients with deficient IVC rim (<5 mm), who underwent catheter closure (April 2007 to June 2008) were reviewed. General anesthesia and transesophageal echo (TEE) guidance was used in all. The IVC rim was imaged at 70 degrees-90 degrees with retroflexion of the TEE probe, in addition to the conventional views. Devices 1-4 mm > maximal ASD size were selected. Deployment was accomplished either from the left atrium, left upper or from the right pulmonary veins. The median age was 5.5 (2.5-27) years and median weight was 19.5 (9-65) kg. The defects measured 16-32 mm and 18-36 mm septal occluders were used. The median fluoroscopic time was 13.1 (4.2-32.7) min. Initial device selection was revised in four patients. Two patients had residual flows at IVC margin. The device embolized to right ventricular outflow tract in one patient. This was retrieved, and a larger device was deployed. No other complications were observed immediately or on follow-up (median 6; range 1-14 months). Transcatheter closure of ASDs with deficient IVC rim is feasible under TEE guidance. The modified retroflexed view allows adequate imaging of IVC rim through TEE.

Spontaneous Echocardiographic Contrast Indicating Successful Endoleak Management

A 75-yr-old woman was admitted with an enlarging descending thoracic aortic aneurysm (TAA). The patient had undergone open repair 12 yr before this admission. Tomographic scanning revealed a 9.9 9.6 cm proximal TAA with dilation of the ascending aorta and thrombus within the aneurysm. It extended from the proximal descending aorta at the level of the pulmonary bifurcation to the distal descending thoracic aorta. Given her risk profile, she was scheduled for endovascular repair. A transesophageal echo (TEE) examination performed after induction of anesthesia confirmed the preoperative findings along with mild aortic insufficiency. A “TAG” thoracic endoprosthesis (WL Gore, Newark, DE) was deployed with the distal end within the previous graft. A second TAG endoprosthesis was deployed proximal to the first, covering the left subclavian artery. Subsequently, both TEE and cine-angiography revealed a large Type IA endoleak (Table 1). The TEE images showed spontaneous echocardiographic contrast (SEC or “smoke”) within the aneurysm, indicating entry of blood into the aneurysm sac (Fig. 1; please see video clip available at www.anesthesia-analgesia.org). Color flow Doppler (CFD) imaging with a reduced velocity scale confirmed these findings (online video clip) and failed to show evidence of patent collateral vessels. A third TAG endoprothesis was then deployed 15 mm proximal to the second device and secured to the aortic walls with a trilobed endoaortic balloon. Subsequently, no further movement of the smoke, which had now acquired echodensity similar or brighter than surrounding tissue, was observed (Fig. 2, and online video clip). Initially, the origin of the flow within the sac could not be determined. However, using different imaging planes, the inflow channel was identified in the proximal stent region. This was confirmed with CFD (online video clip) and angiography. Retrograde flow from a collateral artery (type II endoleak) was considered unlikely, since flow initially was brisk, no flow in the collateral branches could be detected, and flow ceased with further endograft deployment. The primary decision regarding endoleakage and deployment of additional stents was based on angiography, with TEE providing supporting evidence. Her postoperative course was complicated by delayed onset paraparesis. She was discharged on the 16th postoperative day with some improvement. The goal of an endovascular aortic repair is to deploy a graft that seals tightly above and below the aneurysm, excluding the aneurysmal sac from systemic bloodflow to decrease risk of rupture. Although general or regional anesthesia have been used successfully, if TEE is to be used, general anesthesia is required. Small clinical studies have suggested that TEE is more sensitive and specific than angiography in detecting endoleaks (2,3). The disadvantage of angiography is that it relies on a fixed volume of contrast to circulate within the endoleak. Small leaks may be This article has supplementary material on the Web site: www.anesthesia-analgesia.org.

Superior Mesenteric Artery Blood Flow Modifications During Off-Pump Coronary Surgery

Patients undergoing cardiac surgery are at increased risk of gut hypoperfusion. During off-pump surgery, hemodynamic derangements at the time of heart displacement could reduce splanchnic perfusion, outweighing the beneficial effects of avoiding cardiopulmonary bypass. The purpose of this study is to assess, prospectively, blood flow modifications in the superior mesenteric artery during off-pump surgery using transesophageal echocardiography. In 19 patients undergoing multivessel elective off-pump coronary revascularization, systemic hemodynamics and superior mesenteric flow were assessed. Blood flow in the superior mesenteric artery was evaluated with duplex ultrasound using a transesophageal echo probe. Measurements were made four times: T0 (baseline), T1 (left anterior descendent anastomosis), T2 (heart displacement to expose the inferolateral and inferior walls), and T3 (closed chest, at the end of surgery). Superior mesenteric blood flow significantly decreased at T2 (from 426.4 +/- 83.1 mL to 212.9 +/- 48.6 mL, p < 0.001), when also cardiac output was reduced. The percentage of the cardiac output directed toward the mesenteric arterial bed was also decreased at this time. At the end of surgery (T3), whereas cardiac output returned to the initial values, mesenteric flow was significantly increased compared with baseline, with a higher percentage of the systemic output flowing through the superior mesenteric artery. Hemodynamic changes during off-pump coronary surgery induce a significant mesenteric hypoperfusion followed by a hyperemic response at the end of surgery. Transesophageal echo-Doppler allows the intraoperative measurement of blood flow distribution to splanchnic viscera.

Hemiarch replacement during pregnancy (19 weeks) utilizing normothermic selective cerebral perfusion

A 20-year-old woman with Marfan syndrome in the 19 weeks of pregnancy was admitted for a dissecting aneurysm of the ascending aorta to the proximal arch. She wanted to continue with pregnancy. A cardiotocography and a trans-esophageal echo probe which allowed visualization of the fetal heart contraction were attached on the abdomen. A cardio-pulmonary bypass was established via the right axillar and femoral arteries with bicaval drainage. The aortic isthmus and arch branches were clamped. After opening the ascending aorta, selective cerebral perfusion was initiated by quick cannulation into the left carotid and left subclavian arteries. Peripheral pressure was maintained above 80 mmHg with the flow of the selective cerebral perfusion at 1.0 L/min and flow from the femoral artery at 3.5L/min. Hemi-arch replacement was performed using a Dacron graft. The body temperature passively descended to 35 degrees C. She normally delivered a healthy female baby after 37 weeks' of gestation.

Transpharyngeal Ultrasonography for Cannulation of the Internal Jugular Vein

Complications due to internal jugular vein (IJV) cannulation are infrequent and rarely life threatening. However, inadvertent carotid artery puncture can lead to serious problems in patients who have atheromas or bleeding disorders or who are undergoing full anticoagulation therapy, as for cardiopulmonary bypass. An external vascular ultrasound technique, using a vascular probe positioned on the neck, has previously been described as an aid for IJV cannulation.1We have found useful in our practice an alternative method, using a transesophageal probe.During the past year, we selected 50 cardiac patients for whom jugular vein cannulation could present a risk. Patients who required monitoring with a transesophageal probe and who had carotid artery disease, previous carotid artery surgery, and difficult anatomy, such as unclear landmarks or no palpable venous pulse, were selected. The mean age of the patients was 72.3 ± 8.8 yr (median, 74 yr).Transesophageal echocardiographic monitoring is performed with use of a multiplane transducer and a Sonos 5500 imaging system (Hewlett Packard, Andover, MA). Induction of anesthesia and tracheal intubation are performed before insertion of the echo probe. A small towel is placed under the patient’s shoulders. The head is then extended and turned slightly to the side opposite the cannulation, and the patient’s arms are placed by his or her sides. The patient is positioned in a 25° head-down position. The ultrasound monitor is placed in front of the operator.The transesophageal echo probe is inserted 12–20 cm from the teeth. The tip is directed along the pharyngeal lateral wall, which is why we call this method transpharyngeal . The probe is then rotated laterally 15–20° until the cervical vascular bundle is seen. The view is a mirror image of that obtained from conventional vascular ultrasonography (fig. 1).A needle covered with a plastic hood is used to search the skin surface of the neck for the best site of cutaneous insertion to find the IJV, which is not pulsating and does not compress. The ultrasound probe is kept stable on a trolley. The operating field, the operator, and the devices are then prepared as usual under sterile conditions.The skin puncture site is that nearest the IJV, and the puncturing needle is directed away from the carotid artery. The needle is inserted at a 60° angle to the neck axis and directed to the middle of the vein while it is observed on the monitor. Insertion of the needle through the vein may be seen directly, or it may be seen indirectly as movement of the vein wall (fig. 1). Aspiration of blood in the syringe confirms the proper needle position. As the probe is left in place, no adjustment is needed to maintain the correct view.The IJV puncture was successful in 100% of the patients studied. No carotid punctures or other immediate complications occurred.Conventional ultrasound-guided cannulation of the IJV significantly improves the success rate, decreases the access time, and reduces the complication rate of cannulation.2–4Meta-analyses and a systematic review of control data from literature5–7were performed and suggested an advantage of ultrasonography in complicated cases and when access problems were anticipated.1,8At our institution, the widespread use of transesophageal echocardiography, with its ability to provide a view of the vascular bundle of the neck, offers the anesthesiologist a simple way to aid in central venous cannulation, without any additive cost.Potential advantages of transpharyngeal ultrasonography in comparison with conventional ultrasonography in intubated patients undergoing transesophageal echocardiographic monitoring are as follows: Direct compression on the IJV by the external probe is not needed; other professionals do not need to be involved in the procedure; the operator’s hands are free; and the ultrasound probe, still working in the patient, can be used for other purposes.Further studies are needed to assess the reliability of this procedure for IJV cannulation, to determine its proper indications, and to compare this technique with other methods.* Azienda Ospedaliera Universitaria Careggi, Firenze, Italy. sebevi@tin.it

The value of transesophageal echocardiography for endovascular graft stenting of the ascending aorta

YPERTENSION, CONGENITAL valvular abnormalities like bicuspid and unicuspid aortic valves, and the Marfan syndrome are important risk factors for the development of intrathoracic aortic aneurysms. 1 In descending aortic aneurysms, endovascular stenting has become an accepted alternative to open repair in high-risk patients with severe comorbidities. 2,3 In this case report, the authors describe a patient with a Stanford type A dissecting ascending aortic aneurysm undergoing endovascular stenting, illustrating the important contribution of transesophageal echocardiography (TEE) during the procedure. CASE REPORT An 87-year-old female patient with a history of hypertension and anxiety disorder was admitted for treatment of an ascending aortic aneurysm diagnosed after an acute episode of chest pain radiating to the back. Normal electrocardiogram and cardiac enzymes ruled out a myocardial infarction. A spiral computed tomography angiogram showed severe atherosclerotic degeneration, extensive intramural hematoma from the aortic root to the level of the celiac axis, and a Stanford type-A dissection of the ascending aorta with the primary intimal tear in the distal ascending aorta. The ascending aorta was dilated to 5-cm diameter including the hematoma, and the presence of fluid in the mediastinum and pericardium suggested a contained rupture. She was admitted to the intensive care unit to achieve blood pressure control with intravenous esmolol and sodium nitroprusside. The following day, she remained hemodynamically stable with overall good end-organ perfusion. The patient refused a surgical intervention but agreed to undergo stent placement. After induction of general anesthesia, a transesophageal echoprobe was placed. The aortic valve appeared to be trileaflet with moderate regurgitation. The diameter was 2.5 cm at the annulus and 3.3 cm at the sinotubular junction. The ascending aorta had a diameter of 4.2 cm with an intramural hematoma on the anterior wall extending to the right coronary artery (Fig 1) and an intimal flap extending to the aortic arch and descending aorta. The mitral and tricuspid valves were normal. Pericardial and bilateral pleural effusions were found, whereas the myocardial contractility was estimated to be within normal limits. The right brachial and femoral arteries were cannulated, and under TEE guidance, using color flow and the angiomode, a guide wire was passed from the brachial artery entry site to the aortic arch and down to the descending aorta (Fig 2), snared, and pulled out through the vascular sheath in the right common femoral artery. An arch aortogram was performed with a pigtail catheter in the ascending aorta to confirm the position of the guide wire in the true lumen. Afterward, a 10 40 mm stent graft was advanced into the ascending aorta over the guide wire and positioned just distal to the coronary arteries. After confirmation of the optimal position of the stent in the ascending aorta with contrast injections, its deployment was monitored with TEE and fluoroscopy (Fig 3). The patency of the right and left main coronary arteries was verified, and the absence of flow in the false lumen was confirmed with TEE (Fig 4). An arch aortogram showed that the dissection was successfully excluded.

Endoscopic Evaluation of the Esophagus in Infants and Children Immediately Following Intraoperative Use of Transesophageal Echocardiography

Intraoperative transesophageal echocardiography (TEE) has evolved as an essential technique for use during pediatric cardiac surgery; however, few studies have evaluated the safety of TEE in children. This series reports endoscopic examination of the esophagus following intraoperative TEE in pediatric patients. Fifty children undergoing congenital heart surgery underwent flexible esophagoscopy that was performed after completion of their heart surgery and after the removal of the transesophageal echo probe. The patients' ages ranged from 4 days to 10 years old, and their weight ranged from 3.0 to 39.8 kg, with a mean weight of 12.6 kg. Thirty-two of 50 patients (64%) had abnormal results shown on esophageal examinations; this occurred more frequently in the subset of patients weighing < 9 kg. No long-term feeding or swallowing difficulties were noted in any of the 48 patients who survived. Intraoperative TEE in infants and children frequently caused mild mucosal injury. Care must be exercised in the insertion and manipulation of the probes.

Clinical estimation of left and right ventricular volume with open chest compared with transesophageal echocardiography and fast-response thermodilution

A clinical measure--inspection of the relation of the heart (acute margin) to the diaphragm--has shown a strong positive correlation to transesophageal echocardiographic (TEE) determination of left ventricular end-diastolic area (LVEDA) during weaning from cardiopulmonary bypass (CPB). The present study examines the correlation between right ventricular end-diastolic volumes (RVEDV) before and after CPB when using the same clinical measure of left ventricular dimension. Prospective study. Operating room, university hospital. Patients scheduled for elective coronary artery bypass grafting. After induction of anesthesia and endotracheal intubation, a transesophageal echo-probe was inserted. A pulmonary artery right ventricular ejection fraction/volumetric TD catheter was placed in the pulmonary artery. Before going on CPB, a mark was made with cautery at the line of contact between the acute margin and the diaphragm. After CPB, the patients were transfused to the same level. At these two times, TEE recordings of the LVEDA and hemodynamic measurements including calculations of RVEDV were obtained. The LVEDA before and after CPB showed a positive correlation, r = 0.81, p < 0.001. The RVEDV after CPB showed a weak correlation, r = 0.54, p < 0.05, to RVEDV before CPB. There were no significant changes in right ventricular (RV) wall tension calculated as right atrial pressure x RVEDV and pulmonary artery systolic pressure x right ventricular end-systolic volume products. The only significant change regarding hemodynamic parameters was a decrease in mean arterial pressure. It is concluded that there is only a weak correlation regarding RVEDV before and after CPB when the patient is transfused to the line of contact, whereas this clinical measure correlates well with LVEDA.

922-60 How Positionally Stable is a Transesophageal Echo Probe During 3 Dimensional Imaging? Implications for 3 Dimensional Reconstruction

Three dimensional (3D) reconstruction from a single esophageal scanning position requires a stable relationship between the probe and the heart. The purpose of this study was to examine the movement of a transesophageal echo (TEE) probe during 3D image acquisition. A new dual axis multiplane probe was used which includes a miniature (6 × 6 × 9 mm) 6D sensor in the tip. The sensor identifies the probe's 3D position and orientation in space with respect to the location of a magnetic field generator placed beneath the subject. In vivo 3D scans were performed in 5 anesthetized, ventilated dogs. Positional determinations were acquired every 66 ms. The sensor axes were: x-mediolateral. y-superoinferior, z-anteroposterior, and r-radial distance = √(x 2 + y 2 + z 2 ). The movement was estimated by computing standard deviations of the x, y, and z positions during each 3D scan and each cardiac cycle. From 2337 determinations, the mean standard deviation for 10 3D scans and 264 cardiac cycles and histograms of the radial movement were calculated and are shown. x(mm) y(mm) z(mm) r(mm) Total 3D scans 0.63 ± 0.63 0.56 ± 0.64 0.65 ± 0.45 0.57 ± 0.43 Cardiac cycle 0.28 ± 0.36 0.21 ± 0.28 0.25 ± 0.35 0.24 ± 0.35 Probe movement during 3D imaging is measurable and in these anesthetized subjects was within acceptable limits. This capability will be useful in awake patients where greater movement is expected, and will optimize the 3D data set by discarding scans where significant probe movement has occurred.

Echocardiographic guidance during placement of the buttoned double-disk device for atrial septal defect closure.

The usefulness of two-dimensional and Doppler echocardiography during buttoned double-disk device closure of an atrial septal defect was evaluated in 20 consecutive patients at the time of interventional catheterization. Transesophageal echocardiography was used in 11 patients (ages 5 to 62 years, weights 20 to 91 kg). Because of the size of the available transesophageal echo probe, transthoracic echocardiography was used in the remaining 9 patients (ages 4 to 5.5 years, weights 14 to 21 kg). In the transesophageal echo group, 1 patient was found to have no atrial septal defect despite a previous diagnosis by transthoracic echocardiography, 3 patients had atrial septal defects too large for closure despite attempts in 2, and 7 patients had transesophageal echo guided device placement. All of these 7 patients had small residual shunts by color Doppler, 2 had unusual arm positions, and 2 had surgical removal of the device due to embolization to the pulmonary artery in 1 and failure to obtain close approximation of the occluder and counteroccluder in 1. In the transthoracic echo group, 2 patients had atrial septal defects too large for closure, 1 patient had no femoral venous access, and 6 patients had transthoracic echo guided device placement. All of these 6 patients had small residual shunts by color Doppler and 3 of the 6 had unusual arm positions. For atrial septal defect sizing, transesophageal echo measurements correlated with catheter balloon size more closely than did transthoracic echo measurements (r 2 = 0.97 vs 0.86).(ABSTRACT TRUNCATED AT 250 WORDS)