Intraoperative echocardiography in valvular heart disease: an evidence-based appraisal

Intra-operative trans-esophageal echocardiography in heart valve disease

Peri-operative echocardiography is widely used because it provides information that significantly influences clinical/surgical management and improves outcome in patients undergoing cardiac surgery. The role of intra-operative trans-esophageal echocardiography (TEE) in valvular heart disease cannot be emphasized enough. Increasing use of newer surgical techniques-valve repairs and minimal invasive cardiac surgery also warrants intra-operative TEE. It gives us better insight into the anatomy and physiology of the valvular lesion by digital imaging. This manuscript provides an illustrative case based overview of intra operative TEE (IOTEE) in heart valve surgery.

Transoesophageal echocardiography (TOE): contra-indications, complications and safety of perioperative TOE

Transoesophageal echocardiography (TOE) has, in certain clinical situations, become an almost universal monitor and diagnostic tool. In the perioperative environment, TOE is frequently used to guide anaesthetic management and assist with surgical decision making for, but not limited to, cardiothoracic, major vascular and transplant operations. The use of TOE is not limited to the theatre environment being frequently used in outpatient clinics, emergency departments and intensive care settings. Two case reports, one of oesophageal perforation and another of TOE utilization in a patient having previously undergone an oesophagectomy, introduce the need for care while using TOE and highlight the need for vigilance. The safe use of TOE, the potential complications and the suggested contra-indications are then considered together with suggestions for improving the safety of TOE in adult and paediatric patients.

Endoscopic Treatment of Transesophageal Echocardiography-Induced Esophageal Perforation

BACKGROUND

Perforation of the esophagus is the most severe complication of transesophageal echocardiography (TEE) and can lead to mediastinitis, pleural empyema, or peritonitis. Currently, the majority of patients receive operative treatment with only 6% treated endoscopically. We report our experience with endoscopic and conservative approaches.

METHODS

We retrospectively reviewed all patients treated for esophageal perforation and included all patients with perforation caused by TEE. All patients with perforation of the esophagus by TEE probe underwent conservative or endoscopic treatment, drainage of pleural and mediastinal retentions, and adjusted to antibiotic therapy.

RESULTS

From January 2004 to December 2014 a total of 109 patients were treated for esophageal perforation in our department. In 6 patients (5.5%) the perforation was caused by TEE. Location was cervical and midthoracic in 2 and 4 cases, respectively. All patients underwent successful endoscopic treatment and no further surgical procedure, such as esophageal suture or resection was necessary. The mean time between TEE and therapy of the perforation was 7.3 days. In all patients closure of the leakage could be achieved within 30 days. Mortality rate was 0%.

CONCLUSIONS

Esophageal perforations caused by TEE are typically small, in the cervical and mid esophagus, and minimally contaminated. These are good prognostic factors for successful endoscopic treatment with preservation of the esophagus. Operative treatment should only be considered in cases of failed endoscopic treatment.

The Role of Imaging in Aortic Valve Disease

PURPOSE OF REVIEW

Aortic valve disease is the most common form of heart valve disease in developed countries. Imaging remains central to the diagnosis and risk stratification of patients with both aortic stenosis and regurgitation and has traditionally been performed with echocardiography. Indeed, echocardiography remains the cornerstone of aortic valve imaging as it is cheap, widely available and provides critical information concerning valve hemodynamics and ventricular function.

RECENT FINDINGS

Whilst diagnostic in the vast majority of patients, echocardiography has certain limitations including operator variability, potential for measurement errors and internal inconsistencies in severity grading. In particular, low-gradient severe aortic stenosis is common and challenging to diagnose. Aortic valve imaging may therefore be improved with alternative and complimentary multimodality approaches.

SUMMARY

This review investigates established and novel techniques for imaging both the aortic valve and the myocardial remodelling response including echocardiography, computed tomography, cardiovascular magnetic resonance and positron emission tomography. Moreover, we examine how the complementary information provided by each modality may be used in both future clinical practice and the research arena.

The importance of intraoperative transesophageal echocardiography in the surgical decision in cardiac surgery

OBJECTIVE

To determine the importance of intraoperative transesophageal echocardiography (IOTEE) in the surgical decision in patients undergoing cardiac surgery.

PATIENTS AND METHOD

Prospective observational study of patients undergoing cardiac surgery from January 2009 to May 2012, which was monitored with IOTEE by the anesthesiologist in charge. The data collected were: 1) type of surgery; 2) preoperative echocardiographic diagnosis (baseline ECHO); 3) echocardiographic diagnosis before entering cardiopulmonary bypass (CPB) (pre-CPB IOTEE); 4) any differences between the baseline ECHO and the pre-CPB IOTEE (new pre-CPB finding) and whether these differences modified the planned surgery, and 5) echocardiographic diagnosis after disconnection of CPB (unexpected post-CPB finding) and whether these post-CPB echocardiographic findings led to reinstating it. The software program SPSS(®) was used for data analysis.

RESULTS

The total number of patients studied was 1,273. Monitoring with IOTEE showed "new pre-CPB" findings in 98 patients (7.7%), and 43.8% of these led to a change in the scheduled surgery. Of these findings, the most frequent were abnormalities of the mitral valve that had not been diagnosed, and which led to a replacement or repair that had not been scheduled. The incidence of "unexpected post-CPB findings" was 6.2% (79 patients), and 46.8% of those required reinstating the CPB and modifying the surgery performed. The failed valve repairs and dysfunctional valve prostheses were the main causes that led to re-entry into CPB. In the remaining 42 patients, with "unexpected post-CPB findings", there were no changes in the surgical procedure as the echocardiographic findings were not considered to be significant enough to re-establish CPB and revise or change the surgical procedure.

CONCLUSION

Intraoperative monitoring with IOTEE by the anesthesiologist during surgery provides important information before and after the CPB that resulted in modifying surgical management.

Focused critical care echocardiography

OBJECTIVE

Portable ultrasound is now used routinely in many ICUs for various clinical applications. Echocardiography performed by noncardiologists, both transesophageal and transthoracic, has evolved to broad applications in diagnosis, monitoring, and management of critically ill patients. This review provides a current update on focused critical care echocardiography for the management of critically ill patients.

METHOD

Source data were obtained from a PubMed search of the medical literature, including the PubMed "related articles" search methodology.

SUMMARY AND CONCLUSIONS

Although studies demonstrating improved clinical outcomes for critically ill patients managed by focused critical care echocardiography are generally lacking, there is evidence to suggest that some intermediate outcomes are improved. Furthermore, noncardiologists can learn focused critical care echocardiography and adequately interpret the information obtained. Noncardiologists can also successfully incorporate focused critical care echocardiography into advanced cardiopulmonary life support. Formal training and proctoring are important for safe application of focused critical care echocardiography in clinical practice. Further outcomes-based research is urgently needed to evaluate the efficacy of focused critical care echocardiography.

Feasibility and accuracy of a comprehensive multidetector computed tomography acquisition for patients referred for balloon-expandable transcatheter aortic valve implantation

BACKGROUND

The aim of this study was to assess the accuracy of a comprehensive multidetector computed tomography (MDCT) evaluation of the aortic annulus (AoA), coronary artery disease (CAD), and peripheral vessels in patients referred for transcatheter aortic valve implantation (TAVI).

METHODS

In 60 patients referred for TAVI, the following parameters were assessed with 64-slices MDCT and compared with transesophageal echocardiography (TEE), invasive coronary angiography (ICA), and peripheral angiography: AoA maximum diameter (Max-AoA-D(MDCT)), minimum diameter (Min-AoA-D(MDCT)), and area; lumen morphology index ([Max-AoA-D(MDCT)/Min-AoA-D(MDCT)]); length of the left, right, and non-coronary aortic leaflets; degree (grades 1-4) of aortic leaflet calcifications; distance between AoA and left main coronary ostium and between AoA and right coronary ostium CAD and peripheral vessel disease.

RESULTS

The Max-AoA-D(MDCT) and Min-AoA-D(MDCT) were 25.1 ± 2.8 and 21.2 ± 2.2 mm, respectively, with high correlation versus AoA diameter measured with TEE (r = 0.82 and 0.86, respectively). The area of AoA, systolic and diastolic lumen morphology index were 410 ± 81.5 mm(2), 1.19 ± 0.1 and 1.22 ± 0.11, respectively. Aortic leaflet calcification score was 3.3 ± 0.5. The lengths of left, right, and non-coronary aortic leaflets were 14.2 ± 2.4, 13.7.1 ± 2.1, and 14.5 ± 2.6 mm, whereas distances between AoA and the left main coronary ostium and between AoA, and the right coronary ostium were 13.7 ± 2.9 and 15.8 ± 3.5 mm, respectively. Feasibility, negative predictive value, and accuracy for CAD detection versus ICA were 87%, 100% (CI 100-100), and 96% (95% CI 94-100), respectively. All patients (N = 17) who were ineligible for TAVI were correctly detected by MDCT.

CONCLUSIONS

A comprehensive MDCT evaluation of patients referred for TAVI is feasible, provides more accurate assessment than TEE of AoA morphology, and may replace peripheral angiography in all patients and ICA in patients without significant CAD.

Three years' experience of focused cardiovascular ultrasound in the peri-operative period

Ultrasound applications in peri-operative medicine have become common place in modern anaesthesia practice. Anaesthetists have performed transoesophageal echocardiography in cardiac and selected non-cardiac surgery for over two decades. We aimed to assess the indications, impact on clinical management and accuracy of focused cardiovascular ultrasound performed by anaesthetists in the peri-operative period. One hundred and seventy patients over a 3-year period had a focused transthoracic echocardiogram. Adequate images to answer the clinical question were obtained in 167 out of 170 patients (98%). The undifferentiated systolic murmur was the commonest indication (98 out of 170, 58%). Some degree of aortic stenosis was present in 47 out of 170 (26%) of patients; mitral valve disease (30 out of 170 (18%)) and pulmonary hypertension (25 out of 170 (14%)) were also common. Changes in peri-operative management occurred in 140 out of 170 (82%) patients and major findings correlated with a formal cardiology transthoracic echocardiogram in 52 out of 57 (92%) patients. Focused cardiovascular ultrasound performed by anaesthetists in the peri-operative period accurately detects major cardiac pathology and significantly alters peri-operative management.

A Modification of the Trans-Oesophageal Echocardiography Protocol can Reduce Post-Operative Dysphagia following Cardiac Surgery

Use of intra-operative trans-oesophageal echocardiography (TEE) is an independent risk factor for post-operative dysphagia. This study investigated whether modifying the TEE probe-placement protocol could reduce the incidence of post-operative dysphagia. In group I ( n = 100), the TEE probe was inserted after anaesthetic induction and remained in place until the completion of surgery. In group II ( n = 100), the TEE probe was inserted after anaesthetic induction, the heart was examined, then the probe was removed. The probe was inserted again before weaning from cardiopulmonary bypass and then immediately removed after examination. The incidence of dysphagia was significantly higher in group I than in group II patients (51.1% versus 28.6%). Multivariate regression analysis showed that the length of time that the TEE probe was in the oesophagus was an independent predictor of dysphagia. Modification of the TEE protocol in this way can reduce the incidence of post-operative dysphagia in cardiac surgery patients.

Advances in aortic valve repair: focus on functional approach, clinical outcomes, and central role of echocardiography

The surgical classification of aortic regurgitation (AR) is based on cusp mobility. Based on this classification, there are 3 classes of AR: type I is defined as normal cusp mobility, type II is defined as excessive cusp mobility, and type III is defined as restricted cusp mobility. Patients often have multiple coexisting mechanisms. Because aortic valve (AV) repair is safe, effective, and durable, it likely will become a mainstream surgical option for the management of significant AR, even in the setting of a bicuspid valve. Intraoperative transesophageal echocardiography has a central role at all stages in AV repair. Before cardiopulmonary bypass, it can accurately diagnose the mechanism of AR to guide operative strategy for successful repair. After separation from cardiopulmonary bypass, it can comprehensively evaluate the AV repair, including the likelihood that the repair will be durable in the long-term. Important echocardiographic predictors of a durable AV repair include the absence of AR, cusp coaptation above the annular plane, a coaptation length >4 mm, and an effective cusp height >8 mm. The clinical applicability of AV repair continues to expand and likely will evolve into a mainstream surgical therapy for AR, including minimally invasive techniques.