Transesophageal echocardiogram (TEE) device and associated method of performing an echocardiogram

Abstract

The TEE device can have a probe extending along a length between a proximal end and a distal end; an ultrasound transducer disposed at the distal end of the probe; a controller connected to the ultrasound transducer via the proximal end of the probe; a liquid source; and a conduit fluidly connected to the fluid source, the conduit extending along the length of the probe, between the proximal end and one or more outlets.

Description

TRANSESOPHAGEAL ECHOCARDIOGRAM (TEE) DEVICE AND ASSOCIATED METHOD OF PERFORMING AN ECHOCARDIOGRAMBACKGROUND

[0001] At the time of filing this specification, transesophageal echocardiogram (TEE) is the standard-of-care intraprocedural imaging modality for structural heart interventions. A typical TEE device includes an elongated probe, having an ultrasound transducer at its distal end, which is introduced into the esophagus of the patient and positioned adjacent the heart when emitting ultrasound and receiving ultrasound reflections. In a typical scenario, the TEE device is manipulated by a technician who guides a cardiologist performing a cardiac intervention based on the images produced by the TEE. As procedural complexity escalates, procedural time, TEE probe manipulation, and TEE probe’s temperature increase, factors related to an increased risk of TEE-related complications. Also, with prolonged TEE times comes a decrease in image quality. Accordingly, notwithstanding TEE’s history of benefits, there remains room for improvement.SUMMARY

[0002] It was found that at least in some embodiments, the process of performing transesophageal echocardiography could benefit from injection of an edible liquid in the esophagus. One way to achieve this is to make a liquid delivery conduit integral to the elongated probe of the TEE device, and provide a means of pumping the liquid from a liquid source into the liquid delivery conduit and out one or more outlet disposed in the esophagus of the patient during use.

[0003] Indeed, it was found that several benefits may result from introduction of such an edible liquid in the esophagus. One such benefit, in some embodiments, can be an improvement in image quality of the image produced by the operation of the transducer subsequently to the injection of the liquid compared to before (or without) the injection of the liquid. Another such benefit, in some embodiments, can be a reduction in occurrences of lesions which may follow the performing of the procedure. Another such benefit, in some embodiments, can be the reduction in the temperature at the transducer. Another such benefit, in some embodiments, can be to facilitate the manipulation of the TEE device throughout the procedure.

[0004] In accordance with one aspect, there is provided a TEE device comprising : a probe extending along a length between a proximal end and a distal end; an ultrasound transducer disposed at the distal end of the probe; a controller connected to the ultrasound transducer via the proximal end of the probe; a liquid source; and a conduit fluidly connected to the fluid source, the conduit extending along the length of the probe, between the proximal end and one or more outlets.

[0005] In accordance with another aspect, there is provided a process of performing an echocardiogram, the process comprising : inserting a distal end of a probe into an esophagus of a patient, and driving the distal end of the probe into an echocardiogram position located adjacent a heart of the patient; emitting ultrasounds from a transducer disposed at the distal end of the probe; transesophageal echocardiogram, the ultrasounds reflecting off the heart of the patient, and converting the reflections of the ultrasounds into electrical signals by the transducer; converting the electrical signal into an echocardiogram of the heart; and circulating a liquid from a fluid source disposed outside the esophagus, within a conduit extending along a length of the probe, to one or more outlet disposed within the esophagus.

[0006] Many further features and combinations thereof concerning the present improvements will appear to those skilled in the art following a reading of the instant disclosure.DESCRIPTION OF THE FIGURES

[0007] In the figures,

[0008] Fig. 1 is a view of an example of a TEE device;

[0009] Fig. 1A is a schematic cross-sectional view of another example of a TEE device;

[0010] Fig. 1 B is a schematic cross-sectional view of yet another example of a TEE device;

[0011] Fig. 2 is a graph presenting a comparison of median image quality;

[0012] Fig. 3A and 3B are histograms presenting temperature before and after injection of liquid;

[0013] Fig. 4 is a graph presenting a comparison of median manipulation grades;

[0014] Fig. 5 is an image showing a protection tube inserted into an esophagus; and

[0015] Fig. 6 is a view showing a probe introduced into a protection tube.DETAILED DESCRIPTION

[0016] Fig. 1 shows an example of a transesophageal echocardiogram (TEE) device 10. In this example, the TEE device 10 has an elongated member referred to as a probe 12. The probe 12 can be said to have a length extending between a proximal end 16 and a distal end 14. During use of the TEE device 10, the probe 12 may be inserted directly into the esophagus of a patient under general anaesthesia. More specifically, the distal end 14 of the probe may be inserted into direct contact with the tissue of the esophagus, and driven to an echocardiogram position. The distal end 14 of the probe 12 may bear an ultrasonic transducer, and the ultrasonic transducer may be proximate the heart of the patient when in the echocardiogram position.

[0017] A conduit 18 can be provided in a manner to extend along a portion of the length of the probe 12, reaching the region of the distal end 14. A liquid source 20 can be used to supply an edible liquid, such as water for instance, along the conduit 18, and more specifically between an inlet 19 of the conduit and one or more outlets 21. In the example shown in Fig. 1 , the conduit 18 can be embodied as a nasogastric tube secured alongside the probe. More specifically, the tube can be a 10 French gauge pediatric nasogastric tube, which may have two pairs of lateral outlets. The nasogastric tube may be attached to the probe 12 using thread, such as a silk thread, for instance. In the illustrated embodiment, the liquid source 20 can be a syringe which may be actuated manually by a technician, whereas in other embodiments, it may be preferred to automate the delivery of the liquid along the conduit 18 such as by using a pump controlled by a controller, for instance.

[0018] In some embodiments, the TEE device 10 has an elongated, rigid housing 15, which may house one or more controller elements, other electronics, and / or mechanical control components, and a probe 12 extending from an end of the housing 15. The probe 12 has a semi-rigid / semi-flexible portion extending from the proximal end to an end section. The end section, at the distal end 14, can have 10-15 centimeters for instance, and may bear a bulge, or otherwise broader section, nearer the tip, which may house the ultrasonic transducer. Thecontroller housing 15 can have some mechanical control components which, via operation of a mechanical control interface 17 by a user, may be used to change the orientation of the end section.

[0019] Fig. 1A presents a schematic cross-sectional view of another example of a TEE device 110 where the ultrasonic transducer 122 is schematically shown. During use, the ultrasonic transducer 122 may emit ultrasounds which reflect off the heart of the patient, and the reflections may be received by the transducer 22 and converted back into electrical signals. The electrical signals may be converted into an echocardiogram of the heart, and displayed on a display screen. To this end, a controller 127 is typically electrically connected to the ultrasonic transducer 122 via an electrical cable or wire 124 extending along the length of the probe 112, between the proximal end and the distal end 114. The controller can be connected to, or have, a computer, for instance. The electrical cable or wire 124 can be integrated into the probe 112, or attached alongside it, and extend along the length of the probe 12.

[0020] Moreover, an actuator 130 may extend between the mechanical control interface 117 and an articulation 134 disposed at the end section 132. This can afford mechanical control ability which may can help in getting a better signal from the TEE device 110 in varying conditions of use, such as by adjusting the orientation of the end section 132 to achieve a greater image quality.

[0021] One or more outlets 126 of the conduit 118 may be disposed along the probe 112. The conduit 118 may have a tip located before the bulge, or disposed alongside the bulge for instance. One or more outlets 126 of the conduit 118 may be disposed transversally to the length of the probe. The conduit 118 may have more than one outlet, and some or all of the more than one outlets 126 may be longitudinally interspaced from one another.

[0022] In this example, a conduit 118 is also made integral to the probe 112, as opposed to being in the form of a tube attached alongside it. The conduit 118 is fluidly connected, at one end, to a liquid source 120, and fluidly connects the liquid source 120 to one or more outlets 126, along the length of the probe 122. The outlets 126 may be provided in the vicinity of the transducer 122, at the distal end 114 of the probe 112. In this example, the outlets 126are longitudinally adjacent the transducer 122 and do not longitudinally overlap the transducer 122. This may help, in the context of the prototype illustrated in Fig. 1 or Fig. 1A, in avoiding any substantial interference between the conduit 18 and the imaging functionality of the transducer 122. It will be noted that in an alternate embodiment, the conduit 18 may be integrated to the probe 112 and axially overlap with the transducer 122 while being engineered to avoid substantial interference with the imaging functionality.

[0023] Fig. 1 B presents an example alternate embodiment where the conduit 218 is defined via a single-use sleeve 225 having a closed end 240 and an open end 242, which is slipped onto the distal end 214 of the probe 212. The sleeve 225 can be of a plastic and / or elastomeric material, for instance. The conduit 218 is more specifically in the form of a spacing defined between the outer surface of the distal end 214 of the probe 212, and an internal surface of the sleeve 225. The sleeve 225 has apertures defining the outlets 226. Other alternate embodiments are possible.

[0024] Experiments were conducted using the TEE device 10 described above and illustrated in Fig. 1. More specifically, the experiments included an ongoing single-centre, single-arm prospective pilot study of consecutive patients undergoing TEE-guided structural heart interventions. The conduit 18 was provided in the form of a single-use tube, more specifically a pediatric esophageal tube having 4 transversal apertures and one axial aperture longitudinally interspaced from one another along the distal end, attached to the TEE probe before each procedure, and 30-40 ml of 0.5ml / kg room-temperature normal saline used as an edible liquid, gently infused at 15-minute intervals during the intervention with a post-irrigation aspiration of any residual volume from the mouth. The efficacy was evaluated with improvement in image quality with a 5-item scale (1=excellent, 2=good, 3=average, 4=poor, 5=bad), improvement in probe manipulation with a 3-item scale (1=good, 2=average, 3=bad) and the reduction of the probe temperature was also measured. Evaluations were performed by an expert echocardiographer before and after each oesophageal irrigation. Safety was evaluated with the incidence of aspiration pneumonia at 30 days.

[0025] The procedure involved injecting the liquid intermittently between repetitions of the image acquisition by the transducer. More specifically, during the procedure, the distal end of the probe was driven past the echocardiogram position, closer to the stomach, to position theoutlets of the conduit at the echocardiogram position during the injection of the liquid, and the distal end of the probe was retracted back, moving the transducer back into the echocardiogram position, prior to resuming image acquisition. The tube was attached to the probe using 3-0 floss.

[0026] The results of tests performed on the first 21 enrolled patients are presented in Figs. 2 to 4. The median age was 75 [68-83] years, with 52.38% of female patients. The interventions were 66.7% mitral transcatheter edge-to-edge repair (TEEr), 19.0% tricuspid TEEr, 9.5% left atrial appendage closure, and 4.8% transcatheter mitral valve replacement, respectively. The median time of procedural TEE was 83 [62 - 110] min, and the median temperature preirrigation was 38.7 [38.3 - 39.1] °C. The median number of images acquired was 194 [118 - 220], with a median of 19 3D images per procedure. The median number of irrigations per procedure was 5 [4 - 7], with an average of 34 ml per irrigation and a total aspirated volume per procedure of 50 ml. After irrigation, there was a significant change in image quality (see Fig. 2 - Wilcoxon Signed-Rank Test p<0.001) and probe manipulation (see Fig. 4 - Wilcoxon Signed-Rank Test p<0.001). The post-irrigation median probe temperature was 37.6 [37 - 38] °C (see Figs. 3A vs 3B) with a mean decrease of 1± 0.52 °C, which was statistically different (paired sample t-test p<0.001). At the 30-day follow-up, there was 1 case of pneumonia; however, it was an ambulatory-treated community-acquired pneumonia. A decrease of major lesions from 33% to 20% was observed with the injection of the liquid. An increase in treatment speed, possibly due to the combination of better quality images and easier manipulation of the probe, was observed.

[0027] Although preliminary results of a pilot study, the injection of liquid appears to be effective and safe for improving TEE guidance of transcatheter structural heart interventions. After irrigation, there was a significant change in image quality and probe manipulation, as reported by expert echocardiographer operators. Additionally, the IS decreases significantly the probe’s temperature by a mean of 1°C. At 30 days, there were no cases of aspiration pneumonia. The conclusion of this pilot study may establish the foundational framework for this method.

[0028] Various alternatives to the ones exposed explicitly above are possible. For instance, rather than using discrete one or more outlets at a distal end of the conduit, a porous materialmay be used to diffuse the liquid more equally around the distal end of the probe, and more generally, the conduit may be better integrated to the probe. In embodiments where the liquid injection is performed intermittently, the dose of liquid injected at each repetition may be between 10 and 60 ml, between 20 and 50 ml, or between 30 and 40 ml, for instance, and the frequency of the repetitions can be at intervals of between 5 and 30 minutes, or at intervals of between 10 and 20 minutes, for instance. Alternately, the injection of liquid may be continuous or otherwise more progressive than in the example described above. Other edible liquids than saline water, such as physiological serum for instance, may be preferred over saline water in some embodiments.

[0029] In some embodiments, it may be preferred to better protect the proximal portion of the esophagus prior to executing the process. In such embodiments, protective tube 50, which may be referred to as an overtube, may be introduced into the proximal portion of the esophagus prior to insertion of the probe 12. More specifically, the probe 12 may then be introduced into the esophagus via the protective tube 50. An example of a protective tube 50 introduced in the esophagus of a patient is shown in Fig. 5, and an example of how the probe 12 can be introduced across the protective tube 50 is presented in Fig. 6. This is optional and in some cases, it may be preferred to introduce the probe 12 directly into the esophagus.

[0030] In some embodiments, it may be preferred to manufacture the probe 12, or an associated component such as an overtube, in a manner to help manage the possibility that the liquid may reach the mouth of the patient, which may be undesired. For instance, an aspiration tube may be integrated to an overtube in a manner for liquid circulating towards the mouth to be aspired by the overtube.

[0031] In some embodiments, rather than diffusing the liquid through the outlets intermittently, it may be preferred to diffuse the liquid through the outlets continuously. In some embodiments, liquid delivery may be automated in a manner to reduce the number of technicians required during the operation. Automation may be performed via a controller controlling a pump connecting the conduit to a liquid source, for instance.

[0032] As can be understood, the examples described above and illustrated are intended to be exemplary only. The scope is indicated by the appended claims.

Claims

WHAT IS CLAIMED IS:

1. A transesophageal echocardiogram (TEE) device comprising : a probe extending along a length between a proximal end and a distal end; an ultrasound transducer disposed at the distal end of the probe; a controller connected to the ultrasound transducer via the proximal end of the probe; a liquid source; and a conduit fluidly connected to the fluid source, the conduit extending along the length of the probe, between the proximal end and one or more outlets.

2. The TEE device of claim 1 wherein the conduit extends alongside the probe.

3. The TEE device of claim 2 wherein the conduit has a nasogastric tube attached alongside the probe using a thread.

4. The TEE device of any one of claims 1 to 3 wherein the one or more outlets include more than one outlet.

5. The TEE device of claim 4 wherein the more than one outlet includes at least 4 outlets.

6. The TEE device of any one of claims 1 to 5 wherein the one or more outlets include at least one transversally-oriented outlet.

7. The TEE device of any one of claims 1 to 6 wherein the one or more outlets are disposed adjacent the transducer and do not overlap with the transducer relative to the length of the probe.

8. The TEE device of any one of claims 1 to 7 wherein the TEE device further comprises a housing having a mechanical control interface, the proximal end of the probe is secured to the housing, the distal end of the probe extending away from the housing, and havingan articulated tip, the orientation of the articulated tip being controllable via the mechanical control interface.

9. A process of performing an echocardiogram, the process comprising : inserting a distal end of a probe into an esophagus of a patient, and driving the distal end of the probe into an echocardiogram position located adjacent a heart of the patient; emitting ultrasounds from a transducer disposed at the distal end of the probe, the ultrasounds reflecting off the heart of the patient, and converting the reflections of the ultrasounds into one or more electrical signal by the transducer; converting the one or more electrical signal into an echocardiogram of the heart; and circulating a liquid from a fluid source disposed outside the esophagus, within a conduit extending along a length of the probe, to one or more outlet disposed within the esophagus.

10. The process of claim 9 wherein said circulating a liquid is performed continuously over a period of time greater than 5 minutes.

11. The process of claim 9 wherein said circulating a liquid is repeated and interrupted intermittently between repetitions of said emitting ultrasounds and converting the electrical signal.

12. The process of claim 11 wherein each said repetition of said circulating a liquid includes delivering a predetermined volume of said liquid via said one or more outlet.

13. The process of claim 12 wherein said predetermined volume is between 10 and 60 ml.

14. The process of claim 13 wherein said predetermined volume is between 20 and 50 ml.

15. The process of claim 14 wherein said predetermined volume is between 30 and 40 ml.

16. The process of any one of claims 12 to 15 wherein subsequent ones of said repetitions of said circulating a liquid are performed at intervals of between 5 and 30 minutes.

17. The process of claim 16 wherein the intervals are of between 10 and 20 minutes.

18. The process of any one of claims 9 to 17 wherein said inserting distal end of probe into esophagus of the patient includes sliding the distal end of the probe along tissue of the esophagus.

19. The process of any one of claims 9 to 17 further comprising, introducing an overtube into the esophagus of the patient, and wherein said inserting the distal end of the probe into the esophagus of the patient includes inserting the distal end of the probe into a proximal end of the overtube, along the a length of the overtube, and out a distal end of the overtube, into contact with tissue of the esophagus.

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