transoesophagealechocardiographyformonitoringliver surgery ... · concerning in noncardiac surgery....

Hindawi Publishing CorporationCardiology Research and PracticeVolume 2012, Article ID 723418, 6 pagesdoi:10.1155/2012/723418

Clinical Study

Transoesophageal Echocardiography for Monitoring LiverSurgery: Data from a Pilot Study

Filipe Pissarra,1 Antonio Oliveira,1 and Paulo Marcelino2

1 Anesthesiology Department, Hospital Curry Cabral, Rua da Beneficência 8, 1069-166 Lisbon, Portugal2 CEDOC, Faculdade de Ciências Médicas, Lisbon, Portugal

Correspondence should be addressed to Filipe Pissarra, [email protected]

Received 24 April 2011; Revised 18 December 2011; Accepted 14 February 2012

Academic Editor: Antoine Vieillard-Baron

Copyright © 2012 Filipe Pissarra et al. This is an open access article distributed under the Creative Commons Attribution License,which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

A pilot study aimed to introduce intraoperative monitoring of liver surgery using transoesophageal echocardiography (TEE) isdescribed. A set of TEE measurements was established as a protocol, consisting of left atrial (LA) dimension at the aortic valveplane; mitral velocity flow integral, calculation of stroke volume and cardiac output (CO); mitral annular plane systolic excursion;finally, right atrial area. A total of 165 measurements (on 21 patients) were performed, 31 occurring during hypotension. The con-clusions reached were during acute blood loss LA dimension changed earlier than CVP, and, in one patient, a dynamic left ventricu-lar (LV) obstruction was observed; in 3 patients a transient LV systolic dysfunction was documented. The comparison between 39CO paired measurements obtained by TEE and PiCCO2 revealed a statistically significant correlation (P < 0.001, r = 0.83). In thispilot study TEE successfully answered the questions raised by the anesthesiologists. Larger cohort studies are needed to addressthis issue.

1. Introduction

In major surgery haemodynamic complications are likely tooccur; hence for this reason monitoring is necessary to tracephysiological parameters. There are several commerciallyavailable monitoring systems, but transoesophageal echocar-diography (TOE) was not as extensively studied in noncar-diac [1] as it was in cardiac surgery [2–5]. Due to its uniqueability for cardiac imaging, assessing left ventricular (LV)function and right heart chambers dimensions, it is consid-ered promising [5].

The questions faced by anaesthesiologists in noncardiacsurgery are quite different from those in cardiac surgery,where valvular diseases, prosthesis placement and compli-cations are the most relevant. Questions on LV function oracute change in volume status and hypotension are moreconcerning in noncardiac surgery. Good candidates for suchmonitoring are patients submitted to major surgery, espe-cially those undergoing liver surgery or even transplantation[6–8]. During this type of surgery, haemodynamic instabilitycan occur during liver manipulation or due to associatedblood loss.

In our centre, the usual means for monitoring include thecontinuous monitoring of the central venous pressure (CVP)and, in selected cases, the continuous monitoring of cardiacoutput (CO) through the use of the PiCCO system. Pulmo-nary artery catheters, used more often in the past, are nowseldom used. As resident anaesthesiologists felt an increasingneed for a more accurate monitoring, a pilot study aimed tointroduce intraoperative monitoring of liver surgery usingTOE was performed. This study was aimed to evaluate theplace of TOE for liver surgery monitoring and to compareefficiency of TOE measurements with PVC and PiCCO todiagnose hemodynamic instability causes. A set of TOEmeasurements was established as a protocol, after previousdiscussion with the anaesthesiology staff about the requiredinformation. A comparison between the information derivedfrom the monitoring devices used was also performed.

2. Material and Methods

2.1. Patients. This was a 1-year prospective study, which in-cluded patients submitted to liver surgery and enrolled with-out previous selection, although limited to the availability of

2 Cardiology Research and Practice

the anesthesiologists (FP and AO), intensive care specialistwith expertise in the area (PM), and echocardiographyequipment. This pilot study was open with the anaesthesiol-ogists being aware of TOE information. All data was digitallyrecorded for later visualisation, if deemed necessary.

Patients were characterized by age, gender, and body sur-face area. Main diagnoses (for surgical purposes) and comor-bidities were also collected. The main demographic andclinical characteristics of the enrolled patients are presentedin Table 1.

The study protocol was reviewed by the local EthicsBoard, and an informed statement was obtained previous tosurgery.

2.2. Methods. During liver surgery, hypotension and livermanipulation (reported by the surgeons) were the most re-garded situations. Hypotension was considered when meanarterial blood pressure was 60 mmHg or lower, and data wasthoroughly analysed. Blood loss was considered either by thereports from the surgeons or by a decrease in haemoglobinlevels of more than 2 gr/dL. Other possible aetiologies wereevaluated according to the available monitoring devices.

Patients were anaesthetised using a general balanced an-aesthesia, having been intubated after anaesthesia induction.

CVP monitoring was performed continuously using acentral venous line connected to a Philips M4 monitor, wherethe arterial pressure and heart rate were also registered. Thearterial pressure was monitored invasively using an arterialcatheter inserted into a radial or femoral artery. The invasiveCO, when used, was determined using a PiCCO 2 system, forwhich a central venous line and a femoral arterial line wereinserted and then calibrated according to the manufacturer’sinstructions.

2.3. Echocardiography. The TOE monitoring was performedusing a Siemens ACCUSON X300 and a General ElectricLOGIC P6, both equipped with a multiplane transoesophag-eal probe.

Before the study started, a consensus was established withthe anaesthesiologists to determine the information neededfor monitoring. The information considered necessary wasprevious surgery knowledge of the heart anatomy and func-tion; CO; left ventricular (LV) performance; data on volumestatus; right heart chamber evaluation. Special concern wasaddressed to the TOE parameters; they needed to be easilyobtained, not time consuming, in order to permit quick ther-apeutic decisions. It was also established that intragastricviews should not be used so as to avoid interference with thesurgical field. The choice of invasive monitoring was carriedout by the anaesthesiologist’s judgement and independent ofstudy purposes.

After anaesthesia induction, a transoesophageal probewas inserted and the first images obtained. A global exam-ination was first performed and global and segmental wallmotion abnormalities were evaluated, as well as valvular re-gurgitations. The following sets of measurements were cho-sen in order to obtain the information previously required bythe anaesthesiologists. The CO was obtained through the

Table 1: Demographic and clinical characterization of studiedpatients (n = 21).

Age (years, mean, and sd) 54.1 ± 17.6Male (n) 12

Body surface area (m2, mean and sd) 1.73 ± 0.17Liver resection due to metastatic disease (n) 14

Liver resection due to other diseases (n) 4

Liver transplant (n) 3

Past history:

Coronary artery disease 1

Hypertension 2

Diabetes mellitus 2

Other 1

mitral velocity time integral (VTI), measured as follows. Firstthe left ventricular influx by evaluation of the mitral E/Aratio in the 4-chamber view was analysed. Secondly, left ven-tricular CO was assessed by measuring the mitral VTI, calcu-lating the stroke volume index (SVI) and multiplying it byheart rate (Figure 1). Necessary information with regards tothe width of the mitral valve orifice was measured in the sameview (Figure 2). The LV function was assessed through theexternal mitral annulus systolic excursion (MAPSE, consid-ered the most feasible parameter compared to ejection frac-tion and other volumetric parameters) obtained in the same4-chamber view. At the aortic valve plane, during diastolewhen the three aortic cuspids were visible, visible left atrium(LA) area and dimension, obtained from the LA first echo toaortic valve (Figure 3), were determined. Lastly, the assess-ment of right heart chambers was performed; the probe wasrepositioned for the assessment of the right atrium and ven-tricle. The measurement of the right atrial area was empha-sized (Figure 4). All TOE measurements were performed atend-expiration, and other changes detected during TOE wereregistered. TOE evaluation was performed routinely every15 minutes of surgery or whenever considered necessary ifhypotension, blood loss, or liver manipulation were report-ed.

An LV systolic dysfunction was considered wheneverMAPSE was

Cardiology Research and Practice 3

Figure 1: Determination of the mitral VTI.

Figure 2: Determination of the mitral annulus diameter.

3. Results

Overall, 165 TEE dataset measurements were performed, andin 5 patients a PiCCO2 system was present. Overall, 31 reg-istries were performed during hypotension. Of these, 16 (5patients) were due to hemorrhage, 9 (5 patients) without ob-vious cause, and 6 (4 patients) due to liver manipulation.

In the haemorrhage evaluation the LA and RA dimen-sions decreased in all patients, as well as CVP, but it occurredsimultaneously in only two occasions. In the remainingmeasurements (n = 29), TOE modifications preceded CVPchanges by 10 to 15 minutes. In Table 2, and in Figure 5, agraphic representing a registry during an acute blood lossand changes in CVP and visible LA area and dimension ispresented. It was also observed that the LA dimensiondecreased almost uniformly by nearly 20% (19.8% ± 0.9).The comparative data of the parameters previous to haemor-rhage and during haemorrhage is presented.

There were 6 cases of liver manipulation. In two episodeshypotension occurred without changes in CVP. Interestingly,LA and RA dimensions decreased during liver manipulation,but CVP and CO remained unchanged. The comparativedata obtained previous to and during liver manipulation arepresented in Table 3.

In 9 cases (5 patients), a hypotensive episode was docu-mented without blood loss. Within this group, in two cases atypical change in volume status was detected by TOE, butnot by CVP; in one case, a decreased volume status was

Figure 3: Determination of visible LA area and dimension (distancefrom the first echo from LA to aortic valve) in the aortic plane.

Figure 4: Determination of the right atrial area.

identified by both methods; in two cases there was no changeobserved by the two methods; in three episodes (3 patients)a systolic dysfunction was detected by TOE (decrease inCO and MAPSE) in patients with previous normal LV con-tractility. This LV dysfunction was transient and, due to glob-al LV hypokinesia, the recovery was observed within a fewminutes. No apparent cause for this phenomenon wasdetected.

Only one patient presented an LV dysfunction, detectedprevious to surgery, suffering from ischemic heart disease.During surgery, hypotension was detected during a massiveblood loss, and LV dysfunction exacerbated, along withexacerbated wall motion abnormalities. Vasopressor andinotropic support was started, some recovery of LV contrac-tility was observed but the patient remained hypotensive.This patient died in the early postoperative period in theIntensive Care Unit.

Overall, TOE-derived CO varied more markedly thanPiCCO2-derived; the mitral E/A wave form changed duringanaesthesia induction and remained less than one duringmost part of the surgery. The first obtained mean values forthis parameter were 0.99± 0.47 and for the remaining 0.83±0.36 (P = 0.001). However no relevant information couldbe obtained from this parameter during surgery, even duringhypotension/blood losses.

By linear regression analysis, considering CVP as adependent variable and LA dimension and RA area as in-


Table 2: Comparison of hemodynamic and echocardiographical data in hypotension due to blood losses (16 sets of measurements in 5patients).

Parameter Data before hypotension Data during hypotension P

HR (bpm) 71.7± 9.4 74 ± 11.8 nsCVP (mmHg) 6.7± 1.9 5.2± 2.2 0.01LA area (cm2) 9.1± 3.5 5.4± 2.2 0.001LA dimension (mm) 28.5± 4.7 22.8± 4.3 0.001RA area (cm2) 15.1 ± 2.4 13.8 ± 2.6 0.01Mitral E/A 0.73± 0.33 0.76± 0.34 nsPiCCO CO (mL/min) 4322 ± 452 3921 ± 404 0.001TOE CO (L/min) 4571 ± 472 3622 ± 463

Cardiology Research and Practice 5

0

1000

2000

3000

4000

5000

6000

0 1000 2000 3000 4000 5000 6000 7000

CO obtained by PiCCO

CO

obt

aine

d by

TE

E

Figure 6: Dispersion graphic comparing the cardiac output ob-tained by PiCCO2 and TEE (P < 0.001, r = 0.83).

may be considered an early adaptive phenomenon in order toensure LV filling pressure (during volume loss the decrease inLA dimension prevents further decrease in LA pressure andconsequent LV filling pressure). Interestingly, the same chan-ges were observed during liver manipulation, which results indecreased preload due to vascular compression. This infor-mation is important and allows the anaesthesiologist to an-ticipate adequate therapeutic actions. To our knowledge, thisfinding has not yet been described in the literature. However,RA area was the parameter with a statistically significant as-sociation with CVP, not the LA dimension.

The present study evaluated preload not preload depen-dency, using comparative data from static parameters.Among the possible parameters, left ventricular end diastolicarea (LVEDA) could not be considered as transgastric viewswere not obtained [9]. Dynamic concepts for fluid admin-istration [10, 11] and preload dependency were not alsoconsidered in the present study. Only when PiCCO systemwas inserted could the anaesthesiologists evaluate the systolicvolume variation, and fluids were often administered when-ever this parameter was >15%, regardless of haemodynamicstatus. Several TOE parameters can be used to assess preloaddependency [12, 13], and in some settings they were usedto guide intraoperative fluid administration. In this regardwe must consider that the protocol was formulated in orderto detect and characterize acute changes, not to guide fluidadministration. The emphasis was acute volume loss mainlyblood losses that should be rapidly treated. In other words,we focused on acute phenomena.

CO has gained particular attention as a way of accessingthe global circulatory status, but how accurately this variablemeasures the adequacy of circulatory flow is yet to be estab-lished. Perhaps the usefulness of CO consists in detectingchanges in this variable during surgery, especially duringepisodes of instability. Considering this as the main use ofCO monitoring, the changes are more important than itsabsolute value. Using TEE, CO was monitored through themitral pulsed-Doppler influx, an occasionally used method[14, 15]. In this method mitral valve annulus was used asa surrogate for cross-sectional area. The accuracy of mitralvalve stroke volume is debatable. The mitral valve orifice doesnot have a perfect geometrical shape; thus it is not used byinvestigators. As we decided not to use intragastric views in

order not to interfere with surgery, this was the possible, non-time-consuming method. The correlation obtained with thePiCCO system was statistically significant (P < 0.001), withr value of 0.83. Although the methods are different theimportance of this parameter is its changes during acuteevents, and in this regard both methods were reliable,although TOE-derived CO presented greater variability thanPiCCO-derived CO.

Left ventricular function was monitored through mitralvalve annular plane systolic excursion, a method widely usedand tested [16, 17]. The LV function monitoring abilityis perhaps one of the most important features of TOEmonitoring. No other means is comparable not even theclassic methods. It was a valuable tool in the approach ofhypotension in one patient, guiding inotropic and vasopres-sor support and detecting a transient LV dysfunction in other3 episodes of hypotension. This detection was only possiblebecause TOE monitoring was present, and we could notdetect a cause for this phenomenon. Also, we could not find asimilar description in the literature. Although an experiencedobserver could detect changes in LV function subjectively,MAPSE was used in this pilot study as an objective measure-ment. One should remember that LV systolic dysfunction canalso be easily detected by simultaneous changes in mitral VTIand MAPSE.

Other possibilities of TOE were not observed in thisstudy, for example, the detection of right heart overload andalterations in cardiac chambers, mainly due to gas embolismor thrombus formation. In a larger cohort study they couldpossibly be observed.

5. Study Limitations

In this pilot study the preload determination was consideredrather than preload dependency. The invasive counterpartfor preload dependency estimation can be the systolic vol-ume variation, and several TOE parameters can be used toevaluate, such as the analysis of superior vena cava, an easyprocedure to carry out during TOE examination. This needwas not particularly expressed by anaesthesiologists, morefocused on acute and life-threatening phenomena and LVfunction. But in future protocols this item can be used. Someother measurements could be considered but, as we limitedthe information to a non-time-consuming acquisition inorder to describe an easy-to-use tool during anaesthesia,most information was limited. More complex data can beobtained through this technique which, yet due to timeconstraints typical of an operating theatre, went beyond thescope of this study.

In the future it is also necessary to enrol patients whopresent atrial fibrillation, in order to fully understand thelimitations of TOE monitoring.

Another question regards TOE possibilities. Right heartdysfunction and/or overload could not be detected in thepatients studied, but it can be an advantage in the use of TOE.Other conditions resulting from the cardiac imaging (valvu-lar regurgitations, intracardiac masses or thrombi) can alsopresent an advantage, not observed in the studied patients.


6. Conclusion

The use of a TOE monitoring was possible during liver sur-gery, in order to assess volume status, LV function, and CO.In five patients monitored with the PiCCO system, a statisti-cally significant correlation between CO obtained by mitralvalve VTI was obtained. TOE was also useful during episodesof hypotension, detecting changes in volume status earlierthan invasive tools.

TOE is a possible and valuable tool in monitoring liversurgery, and its use by anaesthesiologists should be encour-aged. More data is needed to establish its role in other non-cardiac surgery monitoring.

References

[1] E. Catena and D. Mele, “Role of intraoperative transesophag-eal echocardiography in patients undergoing noncardiac sur-gery,” Journal of Cardiovascular Medicine, vol. 9, no. 10, pp.993–1003, 2008.

[2] M. Minhaj, K. Patel, D. Muzic et al., “The effect of routine in-traoperative transesophageal echocardiography on surgicalmanagement,” Journal of Cardiothoracic and Vascular Anesthe-sia, vol. 21, no. 6, pp. 800–804, 2007.

[3] N. Kolev, R. Brase, J. Swanevelder et al., “The influence oftransoesophageal echocardiography on intra-operative deci-sion making. A European multicentre study. European Peri-operative TOE Research Group,” Anaesthesia, vol. 53, pp. 767–773, 1998.

[4] A. A. Klein, A. Snell, S. A. M. Nashef, R. M. O. Hall, J.D. Kneeshaw, and J. E. Arrowsmith, “The impact of intra-operative transoesophageal echocardiography on cardiac sur-gical practice,” Anaesthesia, vol. 64, no. 9, pp. 947–952, 2009.

[5] D. C. Oxorn, “Intraoperative echocardiography,” Heart, vol.94, no. 9, pp. 1236–1243, 2008.

[6] Y. Ozier and J. R. Klinck, “Anesthetic management of hepatictransplantation,” Current Opinion in Anaesthesiology, vol. 21,no. 3, pp. 391–400, 2008.

[7] A. J. Burtenshaw and J. L. Isaac, “The role of tras-esophagealechocardiography for perioperative cardiovascular monitor-ing during orthotopic liver transplantation,” Liver transplan-tation, vol. 12, pp. 1577–1583, 2006.

[8] D. B. Wax, A. Torres, C. Scher, and A. B. Leibowitz, “Trans-esophageal echocardiography utilization in high-volume livertransplantation centers in the United States,” Journal ofCardiothoracic and Vascular Anesthesia, vol. 22, no. 6, pp. 811–813, 2008.

[9] J. Renner, M. Gruenewald, P. Brand et al., “Global end-diastol-ic volume as a variable of fluid responsiveness during acutechanging loading conditions,” Journal of Cardiothoracic andVascular Anesthesia, vol. 21, no. 5, pp. 650–654, 2007.

[10] P. E. Marik, R. Cavallazzi, T. Vasu, and A. Hirani, “Dynamicchanges in arterial waveform derived variables and fluidresponsiveness in mechanically ventilated patients: a system-atic review of the literature,” Critical Care Medicine, vol. 37,no. 9, pp. 2642–2647, 2009.

[11] B. Tavernier, O. Makhotine, G. Lebuffe, J. Dupont, and P.Scherpereel, “Systolic pressure variation as a guide to fluidtherapy in patients with sepsis-induced hypotension,” Anes-thesiology, vol. 89, no. 6, pp. 1313–1321, 1998.

[12] N. G. Goddard, L. T. Menadue, and H. G. Wakeling, “A case forroutine oesophageal Doppler fluid monitoring during majorsurgery becoming a standard of care,” British Journal of Anaes-thesia, vol. 99, no. 4, p. 599, 2007.

[13] T. D. Phan, H. Ismail, A. G. Heriot, and K. M. Ho, “Im-proving perioperative outcomes: fluid optimization with theesophageal doppler monitor, a metaanalysis and review,” Jour-nal of the American College of Surgeons, vol. 207, no. 6, pp. 935–941, 2008.

[14] W. E. Miller, K. L. Richards, and M. H. Crawford, “Accuracyof mitral Doppler echocardiographic cardiac output determi-nations in adults,” American Heart Journal, vol. 119, no. 4, pp.905–910, 1990.

[15] P. Nissen, J. J. Van Lieshout, S. Novovic, M. Bundgaard-Nielsen, and N. H. Secher, “Techniques of cardiac output mea-surement during liver transplantation: arterial pulse wave ver-sus thermodilution,” Liver Transplantation, vol. 15, no. 3, pp.287–291, 2009.

[16] Y. Cevik, M. Degertekin, Y. Basaran, F. Turan, and O. Pektas, “Anew echocardiographic formula to calculate ejection fractionby using systolic excursion of mitral annulus,” Angiology, vol.46, no. 2, pp. 157–163, 1995.

[17] M. F. Elnoamany and A. K. Abdelhameed, “Mitral annularmotion as a surrogate for left ventricular function: correlationwith brain natriuretic peptide levels,” European Journal ofEchocardiography, vol. 7, no. 3, pp. 187–198, 2006.

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