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A Systematic Approach to Substernal EpicardialEchocardiographic Examination

Fabio Sangalli, MD,* Francesco Formica, MD,† Bruna Manetti, MD,* Margherita Trabucchi, MD,*

Leonello Avalli, MD,* Giovanni Paolini, MD, PhD,† and Antonio Pesenti, MD, PhD*

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Objective: The importance of echocardiography in the

erioperative management of cardiac surgical patients is

idely appreciated. A modified mediastinal drain has been

eveloped, which allows the introduction of a standard TEE

robe in a closed-ended sleeve coupled with the drain to

ermit epicardial echocardiographic imaging after chest clo-

ure (substernal epicardial echocardiography [SEE]). The

im of the present study was to develop a standardized and

omprehensive SEE examination sequence to allow repeat-

ble examinations with a single movement of the TEE probe

nside the drain.

Design: Prospective observational protocol.

Setting: Tertiary care university hospital.

Participants: Ten adult patients undergoing elective car-

iac surgery.

ave informed consent for the insertion of the modified mediastinal

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ournal of Cardiothoracic and Vascular Anesthesia, Vol 21, No 2 (April), 20

ients undergoing elective myocardial revascularization to

evelop a standard examination sequence.

Measurements and Main Results: The examination se-

uence includes 11 views with all the structures relevant for

ostoperative monitoring. The entire sequence is performed

ith a single in-out movement of the transesophageal probe

o minimize discomfort to patients and the risk of damaging

he tube.

Conclusions: This new approach to the perioperative mon-

toring of cardiac surgical patients represents an option for

atients in whom TEE is contraindicated or multiple exam-

nations are anticipated because SEE examinations can be

erformed without the need for sedation in awake patients.

2007 Elsevier Inc. All rights reserved.

EY WORDS: echocardiography, cardiac surgery, postoper-

Interventions: Twenty-three SEE examinations in 10 pa- ative care, hemodynamic assessment

CHOCARDIOGRAPHY HAS BECOME a fundamentaltool in the hemodynamic assessment of postoperative car-

iac surgical patients.1,2 The ideal examination method shouldntail minimal or no invasiveness and optimal monitoring andiagnostic capabilities. The approach of choice with respect tonvasiveness would be represented by transthoracic echocardio-raphy (TTE), but TTE seldom allows a complete and di-gnostic examination in this period because of the supineosition, surgical wounds and dressings, chest tubes, andechanical ventilation. For this reason, transesophageal

chocardiography (TEE) is widely used in the postoperativeardiac patient. However, this technique also has limitationsnd contraindications3-5; moreover, its moderate invasive-ess and the need for a certain degree of sedation make itnsuitable for repeated or continuous monitoring.Epicardial echocardiography was developed and used in the

ntraoperative period long before TEE and still has a role in theperating room.6 A modified mediastinal drain has recentlyeen introduced (SEE-IT; Medtronic, Minneapolis, MN) tollow epicardial imaging after chest closure (substernal epicar-ial echocardiography [SEE]). The SEE-IT device is a medi-stinal silicone drain coupled with a separate, closed-endedltrasound transducer sleeve that permits the introduction of atandard TEE probe. A few preliminary reports have beenublished on the safety and applicability of this technique, andset of proposed indications has been published.7-10

The authors developed a set of standard SEE views to allowsystematic approach to the SEE examination with a single

n-out movement of the TEE probe inside the drain to minimizeatient discomfort and the risk of damaging the probe.

METHODS

To develop the present SEE sequence, the SEE-IT tube was inserted,nd SEE examinations were performed in 10 adult patients (mean age,8.7 years; range, 57-83 years, females:males � 3:7) scheduled forlective cardiac surgery (myocardial revascularization in all patients,ith associated mitral valve repair in 3 patients). The study protocolas reviewed by the institutional ethics committee, and all patients

rain and for the execution of perioperative echocardiography (asoutinely done at the authors’ institution). Anesthesia and surgery wereonducted following the usual institutional protocols, and intraopera-ive TEE was performed in all patients.

Before closure, chest tubes were inserted, and the conventionalnterior mediastinal drain was replaced by the SEE-IT tube. This wasnserted through a 3-cm left subcostal incision and placed parallel to theeft anterior descending artery, with its distal tip located over the distalscending aorta and the brachiocephalic artery (Fig 1).

The TEE probe (Acuson V5M; Siemens AG, Erlangen, Germany)as inserted in the SEE-IT sleeve in all patients. The first patient was

he only one in whom difficulty was experienced in introducing therobe because of insufficient dilation of the rectus muscle and fasciauring placement of the tube. Two examinations were planned for eachatient: the first one after admission to the cardiac intensive care unit,nder sedation, and the second one on the first postoperative day,efore removal of the mediastinal drains.

RESULTS

A total of 23 complete examinations were performed, at leastfor each patient; in 2 patients, additional SEE examinationsere performed for clinical reasons (hemodynamic instability).he quality of images was excellent in all patients.Eleven SEE views were used to include all the structures

elevant for postoperative monitoring. The sequence was struc-ured to minimize the movements of the TEE probe in the drain,he possibility of damage to the tube, and the discomfort toatients. No additional sedation was required in awake patientso perform the examination, and only a few patients reported a

From the Departments of *Anesthesia and Intensive Care and †Car-iac Surgery, Ospedale San Gerardo dei Tintori, University of Milano-icocca, Monza, Italy.Address reprint requests to Fabio Sangalli, MD, U.O.S. di AnestesiaTerapia Intensiva Cardiochirurgica, Dipartimento di Anestesia e

ianimazione, Ospedale San Gerardo via Pergolesi 33, I-20052onza, Italy. E-mail: f.sangalli@hsgerardo.org© 2007 Elsevier Inc. All rights reserved.1053-0770/07/2102-0013$32.00/0

doi:10.1053/j.jvca.2006.08.007

23707: pp 237-242

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238 SANGALLI ET AL

olerable dull pressure-type pain as the probe head passedhrough the rectus sheath (possibly because of suboptimalilation of the muscle fascia during positioning of the drain),hereas no discomfort was noted during examination.Following is the description of the views, which are reported

n Figure 2:1. Aortic arch long-axis (LAx): with the probe fully in-

serted in the drain and the multiplane probe imagingplane at 100° to 120°, the aortic arch and the emer-gence of the epiaortic vessels are visualized.

2. Ascending aorta LAx: the probe is withdrawn 3 to 5 cmfrom the distal tip and the imaging plane placed at 75°to 90° to expose the full length of the ascending aorta.

3. Ascending aorta short-axis (SAx): with the probe in thesame position, the imaging plane is reduced to 0° to20°, allowing visualization of the ascending aorta inshort-axis and the main and right pulmonary arteries.

4. LV inflow-outflow LAx: the probe is withdrawn 5 to 7cm from the distal tip, with the imaging plane still at 0°to 20°; structures are visualized similar to the TTEparasternal long-axis view; the left ventricular posteriorwall is seen inferiorly and the anterior interventricular

Fig 1. The SEE-IT tube in place. (Color version of figure is available

nline.)

septum superiorly. a

5. Aortic valve SAx: with the probe withdrawn 6 to 8 cmfrom the distal tip, the imaging plane is placed at 0° to20°, visualizing the aortic valve in short-axis in a viewsimilar to the TTE parasternal aortic valve short-axisview.

6. Four-chambers LAx: the probe is withdrawn 8 to 10 cmfrom the distal tip, and the imaging plane placed at100° to 120°, resulting in a view similar to the TTEapical 4-chamber view.

7. Tricuspid valve LAx with the probe and the imagingplane in the same position; the TEE probe is slightlyrotated counterclockwise to expose the right chambers.

8. Mitral valve SAx: with the probe in the same position,the imaging plane is placed at 100° to 120° to visualizethe mitral valve short-axis view; the left ventricularanterior wall is seen on the right of the screen and theinferior wall on the left. The right ventricle can also benoted on the upper part of the image.

9. Left ventricle LAx: the probe is withdrawn 9 to 11 cmfrom the distal tip, and the imaging plane is placed at 0°to 20°, visualizing the left ventricle in long-axis withthe inferior wall in the lower part and the anterior wallin the upper part of the image.

10. Left ventricle midpapillary SAx: with the probe in thesame position, the imaging plane is placed at 100° to120°, visualizing the left ventricle in short-axis at themidpapillary level.

11. Left ventricle apical SAx: the probe is withdrawn 11to 13 cm from the distal tip, leaving the imaging planeat 100° to 120°, to visualize the left ventricle inshort-axis at the apical level.

No adverse events were attributable to the SEE-IT tube. Thensertions were uneventful, and neither air leaks nor cases ofube blockage or perforation was observed after the removal ofhe drain. None of the enrolled patients developed sternalound or mediastinal infections. No hemodynamic modifica-

ions (changes in arterial or central venous pressures or heartate) were noted after introduction or during manipulation ofhe TEE probe in the SEE-IT tube. In 2 patients, additionalxaminations were performed for hemodynamic instability;EE was able to clarify the etiology of hypotension in bothases (ischemia and recurrent functional mitral regurgitationfter annuloplasty with a good intraoperative result in the firstatient and acute right ventricular dysfunction in the secondatient) and to monitor the effects of therapy in the secondatient.

DISCUSSION

In the present study, a standardized SEE comprehensivexamination was performed during a single in-out movement ofhe TEE probe in the SEE-IT tube. It was also shown that these of the SEE-IT cannula is feasible, without complicationsnd with minimal or no discomfort to patients (no sedation waseeded to perform the examination in awake patients). Al-hough a compressive effect of the TEE probe on cardiactructures was anticipated, no hemodynamic alterations wereoted in any patient.Epicardial echocardiography represented the first intraoper-

tive ultrasound imaging modality in cardiac surgery before

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239SUBSTERNAL EPICARDIAL ECHOCARDIOGRAPHY

EE probes were available. TEE became popular because ofhe high-quality images and the ability to perform the exami-ation throughout surgery, without the need to interrupt the

Fig 2. The eleven views of the examination sequence. AoV, aortic

orta; RPA, right pulmonary artery; MPA, main pulmonary artery; RV,

trium; TV, tricuspid valve; AML, anterior mitral leaflet; PML, poste

uscle; APM, anterior papillary muscle; LAx, long-axis; SAx, short-a

urgical procedure. Epicardial echocardiography still has a role i

n the operating room in patients in whom the transesophagealpproach is contraindicated or impossible.6

The possibility of obtaining epicardial echocardiographic

e; AscAo, ascending aorta; AoArch, aortic arch; DescAo, descending

ventricle; LV, left ventricle; MV, mitral valve; LA, left atrium; RA, right

itral leaflet; IVS, interventricular septum; PPM, posterior papillary

olor version of figure is available online.)

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maging after chest closure was recently made possible by the

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240 SANGALLI ET AL

anufacture of a modified mediastinal drain (SEE-IT). Thisevice consists of a silicone drain coupled with a separate,losed-ended ultrasound transducer sleeve that allows the in-

Figure

roduction of a standard TEE probe. To obtain best visualiza- a

ion of the structures relevant to postoperative monitoring andeproducible views, the drain has to be inserted through the leftectus muscle and laid over the pericardium parallel to the left

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nterior descending artery, with its distal tip positioned over the

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241SUBSTERNAL EPICARDIAL ECHOCARDIOGRAPHY

istal ascending aorta. The use of SEE was first reported byanlon et al,7 and a few papers have been published since.8,9

xtensive use of SEE in every cardiac patient does not seemustified at this time, mainly because of the costs for theodified drain (the SEE-IT tube costs about US $279 v about

113 for the conventional mediastinal drains used at this insti-ution). The reported cost refers only to the drain, and notudies have been performed to evaluate the economic impactf SEE monitoring on the overall costs of patient management.owever, the authors believe that SEE may play an important

ole in patients with contraindications to TEE or in those inhom repeated echocardiographic evaluations are anticipated.As for every new imaging modality, a standardized compre-

ensive examination protocol is essential to allow reproduciblevaluations. A sequence for the SEE examination was recentlyroposed by Royse et al10 in a study performed in 2 Australianardiac intensive care units; the authors presented a complete

Figure

equence that allowed scanning of most cardiac structures f

elevant for perioperative monitoring. The main limitation ofheir protocol is that it requires multiple movements of the TEErobe inside the drain, exposing the patient to greater discom-ort as the authors noted in a preliminary report11 in which theytated that “in 74% of patients there was significant discomfortequiring sedation.” These movements increase the possibilityf damaging the tube, even though no cases of tube perforationave been reported with the currently commercially availableEE-IT tubes.The present sequence differs from that proposed by Royse et

l10 in 2 aspects. Firstly and most importantly, the aim was toinimize discomfort to the patient and damage to the tube; for

his reason, the motion of the TEE probe was kept to a mini-um. The full examination is performed in a single in-outovement from the first view (probe fully inserted) to the 11th

iew (probe almost completely withdrawn). Second, a cleariew of the right ventricle, which represents a frequent cause

ont’d)

or hemodynamic instability in the postoperative period,12 was

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242 SANGALLI ET AL

btained. This was provided by view 7, in which the rightentricle and right atrium are well visualized, and the tricuspidalve is aligned for Doppler evaluation.In conclusion, it is the authors’ opinion that a combination of

ntraoperative epicardial echocardiography and SEE should beeformed in patients with contraindications to TEE who neederioperative echocardiographic evaluation. Moreover, place-ent of SEE-capable drains appears reasonable in patients

ikely to require multiple echocardiographic examinations inhe postoperative period (ie, patients with severely depressedreoperative cardiac function, acute intraoperative heart failure,entricular-assist devices, or complex procedures). A compre-ensive examination sequence and appropriate training areeeded to standardize the technique; there are no available datat the moment concerning the minimal training needed to

nsure competence in SEE, and the different orientation of the v

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raphic examination. J Cardiothorac Vasc Anesth 17:422-429, 2003

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mages requires that operators perform a certain number ofxaminations to become familiar with this technique. Basednly on the authors’ personal experience, it is believed that ainimum of 20 examinations following the described sequenceay be sufficient to ensure competence in operators certified in

erioperative echocardiography, but this issue has to be furthervaluated. Additional studies are also needed to investigate theost-effectiveness of SEE and its possible limitations.

ACKNOWLEDGMENT

The authors wish to thank all the nursing staff of the Operatoryheatre and CICU of the San Gerardo Hospital for cooperation inonducting the study; Drs Alberto Nava and Enrico Oldani fromedtronic Italia SpA for advice on the SEE-IT tube; R.D. Hersch,omputer & Communication Sciences, Ecole Polytechnique Fédéralee Lausanne, Switzerland, Visible Human Server Project (http://

isiblehuman.epfl.ch) for the anatomic images.

REFE

1. Poelaert JI, Trouerbach J, De Buyzere M, et al: Evaluation ofransesophageal echocardiography as a diagnostic and therapeutic aidn a critical care setting. Chest 107:774-779, 1995

2. Bruch C, Comber M, Schmermund A, et al: Diagnostic usefulnessnd impact on management of transesophageal echocardiography inurgical intensive care units. Am J Cardiol 91:510-513, 2003

3. Kallmeyer IJ, Collard CD, Fox JA, et al: The safety of intraop-rative transesophageal echocardiography: A case series of 7200 car-iac surgical patients. Anesth Analg 92:1126-1130, 20014. Daniel WG, Erbel R, Kasper W, et al: Safety of transesophageal

chocardiography. A multicenter survey of 10,419 examinations. Cir-ulation 83:817-821, 1991

5. Thys DM, Abel M, Bollen BA: Practice guidelines for perioper-tive transesophageal echocardiography. A report by the Americanociety of Cardiovascular Anesthesiologists Task Force on Trans-sophageal Echocardiography. Anesthesiology 84:986-1006, 1996

6. Eltzschig HK, Kallmeyer IJ, Mihaljevic T, et al: A practicalpproach to a comprehensive epicardial and epiaortic echocardio-

CES

7. Hanlon JT, Lowe RI, Furnary A: Substernal epicardial echocar-iography: A new ultrasonic window to the postoperative heart. J Amoc Echocardiogr 13:35-38, 20008. Furnary A, Siqueira C, Lowe RI, et al: Initial clinical trial of

ubsternal epicardial echocardiography: SEEing a new window to theostoperative heart. Ann Thorac Surg 72:S1077-S1082, 20019. Reynolds HR, Nayar AC, McAleer EP, et al: Substernal epicar-

ial echocardiography: Review of a new technique. J Am Soc Echo-ardiogr 16:1204-1210, 2003

10. Royse CF, Royse AG, Bharatula A, et al: Substernal epicardialchocardiography: A recommended examination sequence and clinicalvaluation in patients undergoing cardiac surgery. Ann Thorac Surg8:613-619, 200411. Leggett H, Cope L, Veltman M: A clinical evaluation of the

ubsternal epicardial echocardiography cannula (SEE-IT) device inostoperative patients in the cardiothoracic intensive care. Anaesthntensive Care 31:105, 2003

12. Vlahakes GJ: Right ventricular failure following cardiac sur-

ery. Coron Artery Dis 16:27-30, 2005