Intraoperative Echocardiography

Intraoperative Echocardiography
The Role of the Cardiothoracic Anesthesiologist
As A Best Fit Model for Patient Care
Michael J. Duggan, MD1, Kathryn E. Glas, MD2
1 Director of Perioperative Echocardiography, Chief Quality Officer, Division of Cardiothoracic Anesthesiology , Assistant Professor, Emory University School of Medicine, Atlanta, GA
2 Chief, Division of Cardiothoracic Anesthesiology, Professor, Department of Anesthesiology, Emory University School of Medicine, Atlanta, GA

Introduction
The first reported use of transesophageal echocardiography (TEE) during cardiac surgery was for a mitral valvuloplasty at the Albert Einstein College of Medicine in New York in 1979 [1]. Since that time, intraoperative TEE has gained acceptance and is used in the majority of cardiac surgical procedures in the United States. To adapt to the growing use of this modality and to provide a systematic approach for both its function and role in the operating room, the American Society of Anesthesiologists (ASA) and Society of Cardiovascular Anesthesiologists (SCA) authored practice guidelines in 2010 for the use of intraoperative TEE in cardiac surgery [2]. The document recommends that TEE be utilized in all open heart (valvular) and thoracic aortic surgical procedures and considered for coronary artery bypass (CABG) surgeries. They additionally propose TEE be used for transcatheter intracardiac procedures when general anesthesia is provided and intracardiac ultrasound is not used. Growing evidence supports the ASA/SCA practice guidelines; TEE provides diagnostic information to surgeons and anesthesiologists for critical intraoperative medical decision-making.

Evidence Supporting the use of TEE and Epiaortic Ultrasound
Transesophageal echocardiography has been demonstrated to play an instrumental role in CABG surgery. A 1996 study [3] revealed that intraoperative use of TEE influenced fluid administration decisions 30% of the time and assisted physicians in making 21% of their anti-ischemic therapy choices in the operating room. Importantly, in three percent of patients, a critical surgical intervention was made based on the findings on TEE. A subsequent prospective observational study in 1998 [4] followed 238 consecutive cardiac surgical patients and categorized TEE as requested (specific request for TEE by the cardiac surgeon to assist in planning the procedure) or routine (not requested). TEE resulted in important new diagnostic information in 39 of 184 (21%) routine and 53/54 (98%) requested procedures. Of crucial importance, it was demonstrated that TEE directly led to different surgical procedures being performed in 11 of 184 (6%) routine and 12 of 54 (22%) requested surgeries. A retrospective review [5] of 383 patients undergoing surgery for aortic valve replacement found that 13% of patients had their planned operation altered by intraoperative TEE (most often through inclusion or exclusion of mitral valve intervention).

TEE is utilized to assess the descending thoracic aorta however, due to the anatomic location of the trachea; imaging of the distal ascending aorta is limited. The identification of ascending aortic pathology is critically important during cardiac surgery to mitigate the risk of cerebrovascular accident due to plaque embolization with aortic manipulation or cross-clamp placement. There are instances when the surgical team will change the approach for cardiac revascularization to an off-pump CABG (OPCABG) to decrease the risk of perioperative stroke because epiaortic ultrasound reveals significant disease of the aorta. Compared to on-pump CABG, off-pump surgery decreased the incidence of stroke [6] in part through decreased manipulation of the ascending aorta and the resultant embolic load to the brain. A retrospective review utilizing TEE versus epiaortic for imaging of the ascending aorta in OPCABG patients showed in those receiving partial aortic clamping a significant reduction in early stroke when using EAU vs. TEE alone (0.7% vs. 2.8%, respectively) [7]. This decrease in stroke was not present in the subset of patients who did not receive partial clamping of the aorta as part of their OPCABG, underscoring the importance of EAU for patients receiving planned aortic manipulations. A 2004 study of 20 coronary artery bypass surgical patients compared both preoperative computed tomography (CT) and EAU to diagnose atherosclerotic plaques in the ascending aorta [8]. EAU was found to diagnose a significantly higher rate of atherosclerosis than CT and the authors conclude that EAU should be considered the gold standard for identification of atherosclerosis of the ascending aorta.

Many centers rely on surgical palpation to identify the presence of atheroma though this technique has significant flaws. A 2007 prospective evaluation of 154 CABG patients showed that digital palpation correctly identified 12% of patients as having atheromas vs. 53% identified by EAU [9]. Our institution utilizes EAU for all patients over fifty years of age and for those with significant risk factors for atherosclerotic disease including coronary artery disease. It is our belief that this routine use of EAU is of significant benefit to the neurologic outcome of our patients.

In the Cardiac Anesthesia section of this book, the chapter Epiaortic Imaging of the Ascending Aorta: CT Anesthesiologists’ and Surgeons’ Interventions and the Impact on Stroke Prevention by Zhukov and Glas provides specific and detailed scientific and practical information for using Epiaortic ultrasound for cardiac surgical patients.

Training and Certification of Echocardiographers
Perioperative TEE is a semi-invasive study performed by physicians in the operating room (OR). A TEE service directed by cardiac anesthesiologists is well suited for the operative environment logistics. The anesthesiology staffing model allows the TEE service to have increased availability for ongoing echo assessment during the case. Of equal importance, anesthesiologists are experts in the varied physiologic conditions that occur in the operating room under general anesthesia, which allows them to interpret the echo data and findings in the context of current patient state. The National Board of Echocardiography (NBE) has implemented a testing and certification process for providers interested in pursuing the use of TEE for cardiac surgery. The NBE offers two TEE certificates; the advanced certification is designed for providers who will be making intraoperative diagnoses, including providing direction for surgeons while patients are in the operating room [10]. The basic TEE pathway and certification is intended for non-diagnostic monitoring of surgical patients undergoing non-cardiac surgery. Among other requirements [10], the NBE dictates the study of a minimum of 300 perioperative TEEs by the applicant with at least 150 of those personally performed and interpreted. The background and training objectives behind these requirements are well detailed in the 2002 ASE/SCA Guidelines on training in perioperative echocardiography [11]. Anesthesiologists who aspire to certify in advanced TEE may do so through the NBE via fellowship training in cardiothoracic anesthesiology or alternatively, via a practice experience pathway. The experience pathway is only available for physicians who completed their core residency training before July 1, 2009 [10].

The expertise and diagnostic accuracy of cardiac anesthesiologists has been demonstrated to be equal to that of primary echocardiographers. A 2002 study examined the diagnostic inter-provider accuracy of ten cardiac anesthesiologists compared to two echocardiographers (a cardiologist and radiologist) for 154 comprehensive echoes [12]. The percent agreement of 16 major descriptive fields of cardiac anatomy and function was 83% for anesthesiologist versus radiologist, 80% for anesthesiologist versus cardiologist, and 82% for radiologist versus cardiologist. The paper concluded, “the anesthesiologist and intraoperative echocardiographer need not be mutually exclusive” better defining the cardiac anesthesiologists role in the operating room as the real-time echocardiographer. The perioperative TEE service, established at multiple academic centers and private practice settings, in the country is run solely by anesthesiologists. The cardiothoracic anesthesiology team, within the Department of Anesthesiology at Emory University in Atlanta, Georgia, includes 14 providers anesthesiologists with NBE advanced perioperative TEE certification who perform to complete approximately 1500 cases TEE exams annually.

Safety
TEE has become a standard diagnostic tool in the cardiac surgical operating room with a longstanding safety record. Overall, major complications reported in the outpatient TEE setting ranges between 0.2-0.5% [13]. However, due to the differences in the risk profile of outpatients versus those undergoing cardiac surgery, questions over safety were generated for the same modality in these two varied environments. Intraoperative studies are typically done with patients unconscious and paralyzed rendering them unable to swallow to facilitate probe placement. Additionally, the echocardiogram probe often remains in the esophagus for several hours because serial examinations are necessary over the course of surgery. The high-dose anticoagulation required for cardiac surgery has been theorized to increase the risk of esophageal and/or gastric bleeding in this population.

Despite these differences, the overall complication rate for intraoperative TEE is not significantly higher than the outpatient setting. A case series of 7,200 patients undergoing intraoperative TEE during cardiac surgery demonstrated morbidity attributed to TEE was 0.2% [14]. No patient deaths were ascribed to the intraoperative TEE and the most common complications found in this retrospective analysis was severe odynophagia (0.1%) and dental injury (0.03%). A subsequent study with an increased longitudinal follow-up of 30 days, demonstrated a 1.2% rate of major upper GI complications following cardiac surgery when TEE was used [15]. This included esophageal or gastric perforation, or upper GI hemorrhage requiring transfusion or intervention. It was more likely for these patients to present more than 24 hours after their surgery necessitating continued monitoring for complications in the postoperative period.

Perforation or laceration along the orogastric tract is an infrequent event, but can be a highly morbid injury. An esophageal perforation due to TEE portends an estimated mortality of 10-56%, mortality rate varying with the degree of delay in diagnosis of this condition [16]. Elderly patients (over age 75), and those with pre-existing esophageal pathology, such as stricture or Zenker’s diverticulum, are at an increased risk for this complication [13]. Major upper GI bleeding after TEE & cardiac surgery is a rare complication with a reported incidence of 0.2-1% [16]. Cardiac surgery alone has been shown to cause GI bleeding and a case-controlled study of 40 patients utilizing TEE and 241 not exposed to TEE had no significant difference in postoperative bleeding [17].

TEE probe placement and continued manipulation can also cause damage to the oral cavity, posterior pharynx and dentition. Dental damage is estimated to occur in 0.03-0.1% of patients and the greatest risk factor is poor preoperative dental health. Postoperative odynophagia warranting an EGD is needed in approximately 0.1% of patients [16]. However, in a review of 869 patients undergoing cardiac surgery, with and without TEE, intraoperative TEE was an independent predictor of dysphagia (OR 4.68), with elderly patients (age > 75 years) at highest risk [18].

Absolute contraindications to TEE include prior esophagectomy or esophagogastrectomy, active upper GI bleeding, recent upper GI surgery, and significant esophageal pathology (e.g., Mallory-Weiss tear, stricture, tumor). Relative contraindications include atlanto-axial pathology, history of dysphagia, history of radiation to the chest and recent upper GI bleed [16]. In every case where perioperative TEE is considered, the risks associated with the procedure must be weighed against the perceived benefit to the patient. For cardiac patients with a Class I recommendation for intraoperative TEE, a significant surgical benefit has been demonstrated. In such cases, intraoperative TEE should receive significant consideration for use. In patients in whom TEE is deemed an unacceptable risk, the echo service should have epicardial ultrasound available for intraoperative utilization. Details on how to perform an epicardial exam can be found in the Journal of the American Society of Echocardiography’s review on this topic [19].

Staffing
When initially starting an echocardiography service, it is important that the anesthesiologist spends an appropriate amount of time obtaining, communicating and reading the TEE findings. Having physicians overburdened by an abundance of clinical service requirements will diminish the quality of echocardiography services available. An accurate and skilled echocardiographer can significantly impact patient care and become a reliable and indispensable intraoperative colleague and consultant to the cardiac surgeon. An over-extended echocardiographer can negatively impact surgical decision making by performing an inadequate exam or by rushing a clinical decision. There is no definition as to the minimal amount of time needed for a full echocardiographic exam, however given the complexity of the case and patient, 10-45 minutes has been suggested [20]. This includes the critical time needed for communication between the echocardiographer and surgical/anesthesia teams. Understaffing may hinder an echocardiography service from reaching its maximal value and impact.

The system developed at our institution provides a dedicated anesthesiologist to serve as the echocardiography attending during our busiest hours. This individual’s sole responsibility is performing and reading the intraoperative TEEs and communicating the findings to the surgical team. This frees the anesthesiologist from additional clinical responsibilities allowing them the appropriate time and focus necessary for high quality TEE. This also enables the echocardiographer to electronically report the data, ensure all calculations and measurements are correct on repeat read, and instruct resident and fellow physicians rotating on the echocardiography service. Late afternoons, evening and weekends do not have an additional anesthesiologist to provide this service; the anesthesiologist caring for the patient also performs the TEE. This system allows for a dedicated provider during high volume hours while also requiring that anesthesiologists who work evenings and weekends are competent in perioperative echocardiography.

All of the anesthesiologists on our echocardiography service have obtained certification through the National Board of Echocardiography in advanced perioperative transesophageal echocardiography. CMS does not explicitly state that physicians billing for TEE have this or any particular certification and most third party payers have adopted similar process. According to CMS: “Intraoperative TEE should only be performed by providers who are qualified by training and experience, and who are credentialed by their hospital/medical center to perform and interpret TEE.” [21] Credentialing requirements will vary amongst different institutions but having advanced board certification is a reliable method to prove this expertise should it become necessary.

Quality Improvement
The use of TEE followed by immediate anatomic evaluation by the cardiac surgery team often provides direct feedback for both echocardiographer and surgeon; the joint assessment of the underlying pathology is determined and plan for repair can be made. Often, diagnostic accuracy of perioperative TEE can be judged in the operating room. The immediate validation or rejection of preoperative findings adds to the knowledge and expertise of the intraoperative echocardiographer. Even experienced, well-trained providers will have an echo image or diagnosis that is ultimately proven to be incorrect. A program with a well-run quality improvement program allows for the discussion and presentation of such errors in a blame-free manner to encourage provider and team development.

An error in perioperative echocardiography can involve both misdiagnosis and a missed diagnosis. A misdiagnosis is the result of incorrectly interpreting an image; for instance, diagnosis of an intra-cardiac mass instead of the true presence of lipomatous hypertrophy of the intra-atrial septum. A missed diagnosis is the result of an echocardiographer not identifying pathology due to a missed image or properly obtaining an image but missing an important finding on the image. For instance, an echocardiographer may correctly identify aortic valve endocarditis but fail to see the same disease affecting the mitral valve. Both types of errors can lead to unnecessary intervention or an inappropriate/incomplete surgical procedure or repair. Having a formal collection and review process for such errors serves to educate staff, improve knowledge, and gain the confidence of both the echocardiographers as well as their surgical colleagues. Systematic review and routine quality conferences maintain a high standard of patient care.

The American Society of Echocardiography/Society of Cardiovascular Anesthesiologists issued recommendations for continuous quality improvement in perioperative echocardiography in 2007 [20]. Key suggestions included in this document are as follows:

To maintain competency and ability, an echocardiography service must perform a minimum of 25 exams per month.
Individual providers should read a minimum of 50 exams per year; with at least 25 of such exams personally performed.
Each physician should have an annual minimum of five category I CME credits in echocardiography.
A yearly performance review of five studies for each echocardiographer; specific focus for these evaluations should include comments on the physician’s appropriate use of ultrasound/technology, adequacy and presentation of the images, and concordance between images and written report.

Currently, there is growing consideration and support for the Intersocietal Accreditation Commission (IAC - formerly known as IACEL) to evaluate and grant accreditation to perioperative echocardiography services. The IAC has published standards [22] for quality improvement in adult echocardiography labs, including the following suggestions:

A minimum review of 2 cases per quarter to evaluate the interpretation of ejection fraction, wall motion analysis or degree of valvular regurgitation/stenosis.
The review of 10 reports per quarter to ensure appropriate exam components are documented (M-mode, 2D measurements, Doppler data).
TEE studies should be read within 24 hours of being performed.
Each quality review should involve a significant portion of the echocardiography physician team.

Consideration for these recommendations should be made when setting up the quality review needs for an echocardiography service. Our institution runs 10 faculty conferences per year; during this time, four to five studies are reviewed for accuracy, interesting/rare findings, and use/inclusion of appropriate echo modalities for complete interpretation. Because attendance is mandated at these meetings unless a physician is on-call or vacation, it ensures that a majority of cardiothoracic anesthesiology faculty participate. Exams are selected based on submission and all team members are encouraged to propose cases for review if a study was found to be incomplete, the interpretation of findings incorrect, the exam was challenging, or if review will provide significant learning value for the group. Additionally, the director of the echocardiographic service chooses studies at random and assesses them for completeness, image quality and diagnostic accuracy to minimize selection bias of cases presented. When cases are presented to the group, it is done without identifying the primary echocardiographer to promote a blame-free environment where all staff feel comfortable submitting and reviewing each others’ exams. When appropriate, relevant literature is presented and controversial topics are discussed to enhance the educational value of the program. Our frequent and well-attended reviews with subsequent dialogue serve to strengthen the perioperative echocardiography service and our ability to provide care for our patients.

Study Recording Process
A standard recording and reporting process is essential for an echocardiography team. In current era, as studies are performed, imaging should be stored within the patient’s medical records and accompanied by an electronic report generated by a computer software program. The American Society of Echocardiography recommendations for the use of digital echocardiography include the following [23];

Digital capture, storage, and review should be done regardless of the echocardiography volume or service size.
The DICOM (Digital Imaging and Communications In Medicine) format should be used for storage and data exchange.
Parallel videotape recording is useful for short-term storage solution and will help to ease the digital transformation; however once digital storage capability has been achieved, videotape should not be utilized in the long term.
Integration with computerized reporting software is strongly encouraged.

The ability to electronically read studies and maintain an image database is of vital importance to a high quality echocardiography service. A strong partnership with an information technology (IT) department is crucial to enable this electronic process. IT colleagues are helpful in initiating, maintaining and troubleshooting an echocardiography database. Our institution uses a standardized process to ensure each exam is appropriately linked to the patient’s medical chart and stored as a digital image for review and future reference. The process is as follows:

The surgical team places an order for perioperative echocardiography in the electronic medical record (EMR).
The TEE machine in the operating room is connected to the EMR network, allowing the anesthesiologist to select the order. This directly links the exam images to the patient’s medical chart and ensures that patient data (name, medical record number, date of service) are stamped on the echocardiography exam.
Upon completion of the exam, the study is sent electronically to the network server.
The anesthesiologist then accesses the study on a dual screen computer loaded with software for reading the study
The software includes an electronic template that allows the interpreter to read the exam in a standardized, systematic manner. Additionally, it prompts the echocardiographer to fill in the template with values needed for exam interpretation.
When finished with the echo reading, the anesthesiologist’s report is instantly uploaded into the patient’s electronic medical record and the images are permanently stored in digital format.
The completion of the exam report triggers an indicator for the billing department to file this charge for completed service. Ensuring that studies are submitted for billing helps generate revenue to sustain the service’s costs.

Orders
The cardiothoracic anesthesia service cannot order and perform a diagnostic exam that results in revenue generation for the same service. At our institution, the cardiac surgical team places an order for intraoperative TEE. To ensure that an order is considered prior to surgery for those who may benefit from an intraoperative TEE, the order is listed in the patient’s admission order set. It can be selected or skipped as best serves the patient’s needs. Including the option in the order set serves as a reminder to the surgery team and minimizes last-minute requests for an exam on the day of surgery. The anesthesia team can better plan for staffing and time needed for varied exams when the order sets are completed prior to the patient coming to the operating room. The anesthesia echo order set includes four exam subsets: baseline, epiaortic, intermediate, and chest closure. These study types are fully explained below. If the surgery is emergent and there is insufficient time for the cardiac team to place orders preoperatively, a verbal order for exam is sufficient. The anesthesiologist manually enters the patient information on the study and an electronic order is generated following surgery. Having an order available prior to performing the exam helps to reduce the delay/imperfect pairing of order and study images in the electronic record.

Order Retrieval
All of our TEE machines in the operating room are connected via a hard-wired connection to the server. This allows the anesthesiologist to select the order for the appropriate echo study prior to obtaining echo images. When the exam is complete, images comprising the study are automatically sent from the hard drive of the echo machine to the reading software. This automated process links the study to the correct patient, and images are associated with the electronic medical record for report generation and medical archiving. As mentioned above, when an emergent procedure does not allow preoperative order placement by the surgical team the anesthesiologist manually enters the patient information prior to beginning the study. A limitation created by the lack of an electronic order is that the echo service director has to retrospectively associate the echo images with the order to connect them to the patient’s medical record.

Study Types
Our department has separated perioperative echocardiography into four separate studies: baseline, epiaortic, intermediate, and chest closure. All of these studies are read by an anesthesiologist and archived in the echo database and the medical record. The baseline exam, done prior to surgical intervention, is a complete echocardiographic examination that helps to confirm preoperative diagnosis and follows the 2013 ASE/SCA guidelines [24]. The exam utilizes 2D, Doppler (tissue, color flow, pulsed and continuous wave), M-mode and frequently 3D imaging to cover all cardiac chambers, valves and great vessels.

The epiaortic exam is performed on the majority of our patients over the age of fifty having both on and off pump cardiac surgical procedures. The epiaortic study utilizes short and long axis views of the ascending aorta at proximal, mid, and distal locations as well as the aortic arch in keeping with the ASE guidelines on this topic [25]. This exam allows the anesthesiologist to effectively diagnose ascending aortic diameter, atheromatous disease, plaques and aortic thickening that may not be otherwise appreciated.

The intermediate exam is done immediately following separation from cardiopulmonary bypass. This is a focused exam that assesses the surgical intervention performed as well as interrogation of biventricular function, valvular function and great vessel integrity. To address surgical valve intervention, it is expected that Doppler interrogation for regurgitation and stenosis be completed at this time.

The final echo examination is completed after the sternum is approximated to most closely simulate baseline physiologic conditions. This is a focused exam similar in scope to the intermediate study. If cardiopulmonary bypass is not utilized for a procedure, an intermediate echo is not typically performed.

Reporting
It is an expectation that our anesthesiologists formally read their echoes within 24 hours of study completion. There are dedicated computer workstations with dual monitors and the necessary software to facilitate timely reading of studies. As mentioned previously, development of standard templates enables accurate and efficient echo reading. The templates utilize a series of check boxes (versus free text options) to allow for efficient and standardized reporting. An additional advantage is that we are able to data query our studies for both research and quality purposes. The baseline template is four pages and is the most descriptive of the four templates in use. The TEE study template and description of each page is included (Figures 1,2,3,4).

The epiaortic study template, provided in Zhukov’s chapter in this eBook, divides the ascending aorta into proximal, mid, and distal locations. The mid-ascending aorta is considered to be at the level of the right pulmonary artery; proximal and distal locations are relative to this location. The ascending aorta is further subdivided into right, left, anterior and posterior sections to allow accurate localization of findings as well as to create a standard location to enable clear communication to the surgical team. The severity of atherosclerosis is defined by the depth of penetration into the aorta from the inner edge of the aortic intima and is graded from I-V. This grading system is endorsed by the 2015 ASE Thoracic Aortic Imaging guidelines [26] and is in agreement with the 1992 study by Katz et al [27], which correlated protruding aortic arch atheromas identified by TEE with post CPB stroke. The highest grade found in the ascending aorta is the overall grade reported on the exam. The aortic arch is also imaged and the degree of atherosclerosis reported in the epiaortic template. The inner diameter of the ascending aorta and arch are additionally recorded.

The placement of percutaneous or wire-guided cannulas by surgical team often relies on intraoperative TEE guidance. Placement of arterial and venous cannulas is imaged and documented in both the baseline and epiaortic template to allow for accurate reporting of wire and device placement.

The intermediate and chest closure templates are similar in size and scope. They report detailed doppler information for cases requiring valvular intervention. They also repeat an assessment of biventricular function; great vessel integrity and allows documentation for any complications present with TEE probe removal. It is an expectation that our echocardiographers report their findings to the surgical team; there is a checkbox on each template to document that communication between services has occurred.

Image Storage
As mentioned above in the ASE recommendations [23], echocardiography laboratories should utilize digital storage. For those intraoperative echo services that do not have a large case volume, contracting with the cardiology, radiology or IT department to secure the required storage space is recommended. Our IT division maintains a large database of all ultrasound images in the healthcare system of which intraoperative TEE represents a small fraction. To maintain adequate storage space for incoming images, studies not recently utilized are archived and placed in offline storage. These studies can still be viewed, but there is a slight delay (approximately 15-30 seconds) to retrieve the study from this type of storage.

The amount of space required of an echo service will vary based on the volume of intraoperative studies performed and the content of those studies. For example, from January-June 2015, our division performed and recorded 715 intraoperative baseline studies. The mean image number per study was 51, and required an average of 342 MB of space. Three-dimensional images significantly increase the storage space required of a study, and often these images increase the needed space to several gigabytes. Not only do these images increase the storage space needed but also the retrieval of these studies is delayed due to the file size.

Billing (in the USA)
Billing for intraoperative TEE can be overwhelming and complex if providers are not familiar with the process. To submit an exam for full payment via medical insurance, the echo team needs to be dedicated to understanding the indications for exams, billing codes and documentation requirements. A systematic billing process should be established to ensure accuracy and completeness for each exam submitted for payment.

The study must be for purposes, not for the purposes of monitoring alone.
The surgeon or another physician (not the anesthesiologist) should order/ request the study with a specific diagnostic question.
The study must comprehensively address the diagnostic question(s) and provide a complete interpretation and report.

The appropriate current procedure terminology (CPT) code must be included. The CPT code is chosen according to the type of study that is performed (standard vs. congenital, Doppler vs. 2D only). Examples of CPT codes are listed in (Figures 5,6).

The international classification of disease (ICD-10) code delineating medical necessity must be included. Only certain ICD-10 codes will be paid by insurers. For example, a patient with coronary artery disease alone does not qualify for payment. Please consult your local coverage determination published by CMS [28].
If the TEE is being performed and interpreted by the same anesthesiologist providing the anesthesia care for the surgery, modifier 59 needs to be added. This indicates that the TEE study was a separate diagnostic procedure.
Full payment includes both technical and professional components. If the anesthesia department does not own the echocardiography equipment, only the professional component is billed and modifier 26 is added to the CPT code.

There are several billing options that can be used for partial payment.

If the anesthesiologist placed the probe for monitoring alone, or for an ICD-10 code that is not considered necessary for diagnosis, there is an option to bill for probe placement only. This is CPT code 93313 for a standard study and CPT code 93316 for a patient with congenital heart disease.
If the anesthesiologist does not place the probe, but performs, interprets and documents a full study, the appropriate billing code is CPT 93314 or CPT 93317 for congenital heart disease.

The recently added CPT code for interventional/perioperative TEE needs is 93355. This code is used for procedures that require TEE guidance of a transcatheter intracardiac or great vessel structural intervention. This includes transcatheter aortic valve replacement (TAVR), left atrial appendage occlusion devices, intra-atrial septal closure devices, and minimally invasive non-aortic valve deployments/interventions. This code may be used only once per intervention, and cannot be billed by the individual performing the procedure. It is a comprehensive code thus, it is important that doppler, color flow and 3D images are obtained and are not billed separately.

This code also requires documentation that the structural intervention was successfully completed with echocardiographic guidance; thus it cannot be used for failed procedures.

The rate of payment for perioperative echocardiography will vary depending on geographic location and third party payer contracts among other variables [21]. The Medicare payment rates for our institution, representing several of the standard CPT codes for 2014-15, are listed below. We use the “-26” modifier where appropriate because our hospital owns the echocardiography equipment; it is not the property of the anesthesiology department.

93312-26: complete 2D echo w/ probe placement, image acquisition, interpretation & report: $123.55
93315-26: complete 2D echo for congenital cardiac anomalies w/ probe placement, image acquisition, interpretation & report: $148.11
93321-26: limited Doppler echocardiography, pulsed-wave or continuous with spectral display: $7.53
93325-26: Doppler color flow velocity mapping: $3.58
93313: echocardiography, placement of TEE probe only: $22.93
93355: TEE for guidance of a transcatheter intracardiac or great vessel structural intervention: $229.51

Familiarity with all of the billing requirements and taking the particular diagnostic codes into consideration, our institution is more conservative about submitting exams for payment and currently, we only remit the baseline echo study to the patient’s insurer. This avoids potential accidental double billing and simplifies the process for the billing office. It also blends well with our workflow; the baseline echo is a complete study meeting all of the requirements for full payment whereas our intermediate and chest closure are more narrowly focused as described above.

A system has been developed to assist our reading anesthesiologists with selecting the appropriate ICD-10 code. The title page includes pre-populated indications for exam through a searchable list of ICD-10 diagnoses. This list contains a complete list of ICD-10 codes, even those that cannot be submitted for payment. Our anesthesiologists are instructed to choose the appropriate diagnosis codes and NOT to choose codes based on payment. Our program goal is to bill only studies that meet all requirements for submission as appropriate.

Studies are performed at our institution for patient care and benefit that are not eligible for payment submission. To ensure that the service remains financially viable, our goal is to ensure that studies appropriate for billing are submitted. To reduce the amount of studies that cannot be submitted due to failure of documentation, the IT Department runs a weekly query of the echo database. TEE studies that are completed but not associated with a surgeon’s order are identified. The study is then re-linked to the surgical order, read by the anesthesiologist and submitted for billing. If an order was not placed due to error or emergency case status, the TEE service director reaches out to the surgical team to place a new order or to correct an incorrectly placed order. The anesthesia team also helps to minimize unbilled studies due to technical constraints: each team member will quickly contact the echo service director for issues preventing image acquisition, reading, and interpretation or reporting.

Financial Viability of an Echocardiography Service
A perioperative TEE service staffed and directed by anesthesiologists is financially viable for many institutions. Start-up costs are significant and may require hospital investment. Continued sustainability will vary based on payment rates, staffing models and volume of intraoperative TEE performed. Payment alone is unlikely to completely subsidize the cost of an echocardiographer who is free from other clinical duties. However, in a high volume center such as our own, the benefit of a dedicated anesthesiologist improves the quality of our echo service, allows sufficient time to read images and submit study reports, enables a reliable billing practice, and enhances the education of trainees.

Of note, with increasing focus in health care on quality and cost-effectiveness, a TEE service may provide health system savings when used appropriately. The financial benefit of TEE in various cardiac surgical procedures has been studied [29] and demonstrates that patients undergoing congenital cardiac surgery derived the greatest benefit of TEE, averaging a savings of $600 per case. Valve repair patients had a $450 savings per case and $150 was recovered in valve replacement surgery. CABG surgery was more variable ($100-$300), and depends on the assumption that TEE can be used to decrease the incidence of intraoperative stroke. The article points out that decreased costs are usually the result of making intraoperative diagnoses by TEE that otherwise would have been missed.

Equipment
Significant costs are associated with the purchase of equipment needed to start and maintain a perioperative echocardiography program. The minimum equipment required for an echocardiography service is a two-dimensional echo machine that includes Doppler and m-mode capability. Doppler modes must comprise color flow Doppler (CFD), continuous wave Doppler (CWD), pulsed-wave Doppler (PWD) and tissue Doppler (TDI). The increased penetration provided by three-dimensional echo has made this an increasingly popular technological advancement and is becoming a standard for programs with available financial resources. A typical echo machine should contain a large screen for viewing in the operating room, a hard drive for storage of studies and several methods of study transfer (network connection, USB drive, CD-ROM). Purchase price of the machine will vary depending on several factors including the type of hardware and software installed and incentives available from the manufacturer. A typical system would cost between $150,000-$250,000 [21]; the price can often be reduced by trading in an older ultrasound system.

Though there is ongoing debate about the application of 3D TEE, the ability to more accurately diagnose mitral valve scallop, prolapse, flail and associated chordal rupture has been demonstrated. In a 2008 study [30] of eighteen patients undergoing mitral valve surgery using surgical findings as the gold standard, 2D echo accurately identified the correct prolapsing segment and chordal rupture in only 9/18 patients. Live 3D TEE accurately identified and localized the pathology in 16/18 patients. A subsequent study [31] compared preoperative 2D and 3D TTE and TEE imaging in 40 patients undergoing mitral valve surgery. All four modalities correctly identified organic versus functional mitral regurgitation, but 3D TEE demonstrated the best localization of mitral valve disease using surgical findings as the gold standard. Programs performing high volume mitral valve interventions are encouraged to purchase an echo system with 3D capability.

Depending on the anticipated surgical volume, several TEE probes with multiplane capability should be purchased. These probes need to be easily interchangeable and compatible with the echo machine used by the service. The cost of a probe varies but generally ranges between $20,000-$50,000 each [21]. A perioperative echo service should also invest in probes for epiaortic and epicardial imaging. An epiaortic probe operating greater than 7 MHz is sufficient for most cases. It is advantageous for a perioperative echo service to have access to epicardial ultrasound when TEE is contraindicated or insufficient. For epicardial ultrasound, high frequency transducers (5-12 MHz) provide optimal imaging. Both probes require the purchase of sterile plastic sheaths for their use in the open chest cavity. The American Society of Echocardiography details the uses and application of epicardial ultrasound in their guidelines [19].

Machines and probes are expensive investments and should be treated with caution. Improper handling will damage the machines and probes. A comprehensive maintenance contract will help to protect echocardiographic equipment and guard an expensive investment. Most contracts are included with the original purchase of equipment and cost between $5,000-$20,000 annually, depending on the devices covered and outlined terms of service.

Probe Disinfection/Sterilization
The importance of cleaning and disinfecting echocardiography equipment cannot be overstated. Recently, a case report was published detailing the cases of three patients who acquired Legionella pneuomphila from contaminated probe rinse water [32]. The FDA places TEE transducers in the “critical” classification for sterilization requirements [33]. A sterile sheath is recommended for intraoperative use; however, all transducers should be processed as if a sheath were not present. A small perforation in sheath material or other sheath failure is not easily detected. Additionally, physical inspection of the probes is also of paramount importance in maintaining sterility. Eight patients have contracted a multidrug resistant pseudomonas infection due to a 5mm defect on the surface of a single TEE transducer; this allowed the resistant strain of bacteria to thrive despite adherence to cleaning processes [34].

The FDA recommends TEE transducers be sterilized immediately following an exam. Although high-level disinfection is deemed “minimally acceptable” for less-invasive transducers, the mucous membrane contact of TEE probes places them in the critical category. The difference between high-level disinfection and sterilization is based upon the amount of time the transducer is soaked in the cleaning solution. It is the responsibility of the echocardiography service to be aware of all equipment guidelines, warnings and recommendations for proper cleaning and disinfecting. Both FDA (or similar regulatory body) and manufacturer recommendations should be followed. Our service utilizes Philips equipment and abides by their cleaning and sterilization recommendations [35].

All probes should be cleaned to remove organic material prior to sterilization.
Only approved liquid solutions (no autoclave or gas methods) can be used in the cleaning process.
Immersion of the transducer is limited to the minimum time required by the chemical manufacturer; this reduces exposure risk for the future patients.
Residual Cidex OPA (a disinfectant solution) can cause staining of the lips and mouth and cause chemical irritation and burns of the oropharynx, esophagus and stomach. Cidex OPA should be used for TEE probes.
Following immersion, the transducer needs to be rinsed thoroughly with water and allowed to air dry.
Only the flexible shaft is immersed in the cleaning solution. The connector housing and handle needs to be cleaned with isopropyl-based alcohol.

With these recommendations in mind, our echocardiography service utilizes the following process to process our TEE probes:

A hard plastic bin is brought to the OR to allow placement of the used transducer.The probe is placed in the bin along with a patient sticker for record keeping purposes.A red plastic cover is placed on top of the bin that reads, “Contaminated” to clearly identify the need for sterilization. This hard plastic bin also serves to protect the probes when being transported.
On arrival into the processing room, the submersible portion of the probe is soaked in an ENZOL solution.The probe is gently scrubbed to remove organic debris. The handle, connector housing and cord are wiped down with 70% isopropyl alcohol.
The probe is placed in an automated endoscope processor. Our facility uses a MedivatorTM automated cleaning system that incorporates water rinses with a 5+ minute soak in the primary cleaning agent – Rapicide PA.
Rapicide PA is a peracetic acid-based single-use cleaning solution. It is effective against tuberculosis, hepatitis viruses, Clostridium Difficile, vancomycin-resistant enterococcus, carbapenam-resistant enerobacteriaceae and methicillin-resistant staphylococcus aureus bacterium.
Following the Rapicide soak, the MedivatorTM unit rinses the probe with three separate water washes.
The probe is dried and placed back in a clean hard plastic storage bin with a green plastic cover that reads “Clean”.
The patient sticker is kept in a logbook in the processing room along with details of the disinfection process.
The total turnaround time for this process is between 45-60 minutes.

Conclusion
There are multiple components that need to be in place for the achievement of an effective and efficient intraoperative echocardiography service. Of upmost importance is the recruitment and involvement of anesthesiologists with a commitment to improve patient care through the use of echocardiography. Having collaborative, collegial relationships with the cardiac surgeons, a robust quality component, on-going collaboration with an IT division, knowledge of billing requirements and the proper equipment for all imaging modalities will enable success.