Acute Effect of Mitral Valve Repair on Mitral Valve Geometry.

BACKGROUND: The aim of this study was to quantify acute mitral valve (MV) geometry dynamic changes throughout the cardiac cycle using three-dimensional transesophageal echocardiography (3D TEE) in patients undergoing surgical MV repair (MVR) with ring annuloplasty and optional neochord implantation. METHODS: Twenty-nine patients (63 ± 10 years) with severe primary mitral regurgitation underwent surgical MVR using ring annuloplasty with or without neochord implantation. We recorded 3D TEE data throughout the cardiac cycle before and after MVR. Dynamic changes (4D) in the MV annulus geometry and anatomical MV orifice area (AMVOA) were measured using a novel semiautomated software (Auto Valve, Siemens Healthcare). RESULTS: MVR significantly reduces the anteroposterior diameter by up to 38% at end-systole (36.8-22.7 mm; p < 0.001) and the lateromedial diameter by up to 31% (42.7-30.3 mm; p < 0.001). Moreover, the annular circumference was reduced by up to 31% at end-systole (129.6-87.6 mm, p < 0.001), and the annular area was significantly decreased by up to 52% (12.8-5.7 cm2; p < 0.001). Finally, the AMVOA experienced the largest change, decreasing from 1.1 to 0.2 cm2 during systole (at midsystole; p < 0.001) and from 4.1 to 3.2 cm2 (p < 0.001) during diastole. CONCLUSIONS: MVR reduces the annular dimension and the AMVOA, contributing to mitral competency, but the use of annuloplasty rings reduces annular contractility after the procedure. Surgeons can use 4D imaging technology to assess MV function dynamically, detecting the acute morphological changes of the mitral annulus and leaflets before and after the procedure.

Feasibility of measurements of valve dimensions in en-face-3D transesophageal echocardiography.

Newest 3D software allows measurements directly in the en-face-3D TEE mode. Aim of the study was to ascertain whether measurements performed in the en-face-3D TEE mode are comparable with conventional measurement methods based on 2D TEE and 3D using the multiple plane reconstruction mode with the Qlab® software. En-face-3D TEE is used more frequently in daily clinical routine during cardiac operations. So far measurements could only be done based on 2D images or with the use of multi planar reconstruction mode with additional software. Measurement directly in the 3D image (en-face-3D TEE) would make measurements faster and easier to use in clinical practice. After approval by the local ethic committee and written informed consent from the patients additionally to a comprehensive perioperative 2D TEE examination a real time (RT) 3D zoom- dataset was recorded. Routine measurements of the length of anterior and posterior mitral valve leaflets as well as mitral valve and aortic valve areas were performed in en-face-3D TEE, multiplanar reconstruction mode using Qlab®-software (Philips, Netherlands) and 2D TEE standard views. Twenty nine patients with a mean age of 67 years undergoing elective cardiac surgery/interventions were enrolled in this study. Direct measurements in en-face-3D TEE mode lead to non significant underestimation of all parameters as compared to Qlab® and 2D TEE measurements. Measurements in en-face-3D TEE are feasible but lead to non significant underestimation compared to measurements performed with Qlab® or in 2D TEE views.

Analysis of circumflex artery anatomy by real time 3D transesophageal echocardiography compared to cardiac computed tomography.

Iatrogenic injury to the circumflex artery (Cx) due to its close proximity to the mitral annulus is a rare but dreadful complication that can occur during mitral valve repair. The aim of our study was to compare multiple measurements of the Cx datasets, obtained by real time three-dimensional transesophageal echocardiography (RT3D TEE) and corresponding measurements assessed in multi-planar three-dimensional images acquired by multidetector computed tomography (MDCT). Preoperative RT3D TEE and MDCT datasets of 25 patients who had previously undergone minimally invasive mitral valve surgery were retrospectively analyzed. The vessel diameter and the horizontal as well as vertical distances from the center of the Cx to the mitral valve annulus were measured. Horizontal as well as vertical Cx distances showed a strong correlation between measurements of RT3D TEE and MDCT whereas the measurements of the Cx diameter showed no correlation. Measurements of horizontal and vertical distances of the Cx to the mitral annulus can be performed using RT3D TEE and show good correlation with MDCT-based measurements.

Independent Risk Factors for Fast-Track Failure Using a Predefined Fast-Track Protocol in Preselected Cardiac Surgery Patients.

OBJECTISVES: The purpose of this study was to identify the independent risk factors for fast-track failure (FTF) in cardiac surgery patients. DESIGN: A retrospective analysis. SETTING: A university-affiliated heart center. PARTICIPANTS: In a 2-year period, 1,704 consecutive preselected patients undergoing elective cardiac surgery were treated according to the local fast-track protocol in the postanesthetic care unit (PACU), bypassing the intensive care unit (ICU). MEASUREMENTS AND RESULTS: Independent risk factors for FTF in the univariate regression analysis were tested in a multivariate regression analysis. FTF was defined as any transfer of the preselected patient to the ICU. FTF was primary when the patient was transferred directly from the postanesthetic care unit to the ICU and secondary when the patient was transferred from the intermediate care unit or ward to the ICU. FTF rate was 11.6% for primary and 5.6% for secondary FTF. In the multivariate regression analysis, age>70 years, female sex, prolonged surgery, and prolonged cross-clamp time could be defined as independent risk factors for FTF. CONCLUSIONS: In a preselected patient population, fast-track treatment could be done with a low FTF rate. Independent risk factors for FTF are age, female sex, prolonged surgery, and prolonged cross-clamp time.

Mass-spring systems for simulating mitral valve repair using 3D ultrasound images.

Mitral valve (MV) diseases are among the most common types of heart diseases, while heart diseases are the most common cause of death worldwide. MV repair surgery is connected to higher survival rates and fewer complications than the total replacement of the MV, but MV repair requires extensive patient-specific therapy planning. The simulation of MV repair with a patient-specific model could help to optimize surgery results and make MV repair available to more patients. However, current patient-specific simulations are difficult to transfer to clinical application because of time-constraints or prohibitive requirements on the resolution of the image data. As one possible solution to the problem of patient-specific MV modeling, we present a mass-spring MV model based on 3D transesophageal echocardiographic (TEE) images already routinely acquired for MV repair therapy planning. Our novel approach to the rest-length estimation of springs allows us to model the global support of the MV leaflets through the chordae tendinae without the need for high-resolution image data. The model is used to simulate MV annuloplasty for five patients undergoing MV repair, and the simulated results are compared to post-surgical TEE images. The comparison shows that our model is able to provide a qualitative estimate of annuloplasty surgery. In addition, the data suggests that the model might also be applied to simulating the implantation of artificial chordae.

Quantification of mitral valve regurgitation with color flow Doppler using baseline shift.

Vena contracta width (VCW) and effective regurgitant orifice area (EROA) are well established methods for evaluating mitral regurgitation using transesophageal echocardiography (TEE). For color-flow Doppler (CF) measurements Nyquist limit of 50-60 cm/s is recommended. Aim of the study was to investigate the effectiveness of a baseline shift of the Nyquist limit for these measurements. After a comprehensive 2-dimensional (2D) TEE examination, the mitral regurgitation jet was acquired with a Nyquist limit of 50 cm/s (NL50) along with a baseline shift to 37.5 cm/s (NL37.5) using CF. Moreover a real time 3-dimensional (RT 3D) color complete volume dataset was stored with a Nyquist limit of 50 cm/s (NL50) and 37.5 cm/s (NL37.5). Vena contracta width (VCW) as well as proximal isovelocity surface area (PISA) derived EROA were measured based on 2D TEE and compared to RT 3D echo measurements for vena contracta area (VCA) using planimetry method. Correlation between VCA 3D NL50 and VCW NL50 was 0.29 (p < 0.05) compared to 0.6 (p < 0.05) using NL37.5. Correlation between VCA 3D NL50 and EROA 2D NL50 was 0.46 (p < 0.05) vs. 0.6 (p < 0.05) EROA 2D NL37.5. Correlation between VCA 3D NL37.5 and VCW NL50 was 0.45 (p < 0.05) compared to 0.65 (p < 0.05) using VCW NL37.5. Correlation between VCA 3D NL37.5 and EROA 2D NL50 was 0.41 (p < 0.05) vs. 0.53 (p < 0.05) using EROA 2D NL37.5. Baseline shift of the NL to 37.5 cm/s improves the correlation for VCW and EROA when compared to RT 3D NL50 planimetry of the vena contracta area. Baseline shift in RT 3D to a NL of 37.5 cm/s shows similar results like NL50.

Real-time three-dimensional echocardiographic assessment of mitral valve: Is it really superior to 2D transesophageal echocardiography?

Aim of our study was to investigate the feasibility of use and possible additional value of real-time 3D transesophageal echocardiography (RT-3D-TEE) compared to conventional 2D-TEE in patients undergoing elective mitral valve repair. After ethical committee approval, patients were included in this prospective study. After induction of anesthesia, a comprehensive 2D-TEE examination was performed, followed with RT-3D-TEE. The intraoperative surgical finding was used as the gold standard for segmental analysis. Only such segments which were surgically corrected either by resection or insertion of artificial chords were judged pathologic. A total of 50 patients were included in this study; usable data were available from 42 of these patients . Based on the Carpentier classification, the pathology found was type I in 2 (5%) patients, type II in 39 (93%) patients and type IIIb in 1 (2%) patient. We found that 3D imaging of complex mitral disease involving multiple segments, when compared to 2D-TEE did not show any statistically significant difference.RT-3D-TEE did not show any major advantage when compared to conventional 2D-TEE for assessing mitral valve pathology, although further study in a larger population is required to establish the validity of this study.