Yannis Amador

Hemodynamic Testing of Patient-Specific Mitral Valves Using a Pulse Duplicator: A Clinical Application of Three-Dimensional Printing

OBJECTIVE To evaluate the feasibility of obtaining hemodynamic metrics of echocardiographically derived 3-dimensional printed mitral valve models deployed in a pulse-duplicator chamber. DESIGN Exploratory study. SETTING Tertiary-care university hospital. PARTICIPANTS Percutaneous MitraClip procedure patient. INTERVENTIONS Three-dimensional R-wave gated, full-volume transesophageal echocardiography images were obtained after deployment of the MitraClip device. A high-quality diastolic frame of the mitral valve was segmented using Mimics Innovation Suite and merged with a flange. The data were exported as a stereolithography (.stl) file, and a rigid 3-dimensional model was printed using a MakerBot Replicator 2 printer. A flexible silicone cast then was created and deployed in the pulse-duplicator chamber filled with a blood-mimicking fluid. MEASUREMENTS AND MAIN RESULTS The authors were able to obtain continuous-wave Doppler tracings of the valve inflow with a transesophageal echocardiography transducer. They also were able to generate diastolic ventricular and atrial pressure tracings. Pressure half-time and mitral valve area were computed from these measurements. CONCLUSION This pulse duplicator shows promising applications in hemodynamic testing of patient-specific anatomy. Future modifications to the system may allow for visualization and data collection of gradients across the aortic valve.

Artificial Intelligence in Mitral Valve Analysis

Background: Echocardiographic analysis of mitral valve (MV) has become essential for diagnosis and management of patients with MV disease. Currently, the various software used for MV analysis require manual input and are prone to interobserver variability in the measurements. Aim: The aim of this study is to determine the interobserver variability in an automated software that uses artificial intelligence for MV analysis. Settings and Design: Retrospective analysis of intraoperative three-dimensional transesophageal echocardiography data acquired from four patients with normal MV undergoing coronary artery bypass graft surgery in a tertiary hospital. Materials and Methods: Echocardiographic data were analyzed using the eSie Valve Software (Siemens Healthcare, Mountain View, CA, USA). Three examiners analyzed three end-systolic (ES) frames from each of the four patients. A total of 36 ES frames were analyzed and included in the study. Statistical Analysis: A multiple mixed-effects ANOVA model was constructed to determine if the examiner, the patient, and the loop had a significant effect on the average value of each parameter. A Bonferroni correction was used to correct for multiple comparisons, and P = 0.0083 was considered to be significant. Results: Examiners did not have an effect on any of the six parameters tested. Patient and loop had an effect on the average parameter value for each of the six parameters as expected (P < 0.0083 for both). Conclusion: We were able to conclude that using automated analysis, it is possible to obtain results with good reproducibility, which only requires minimal user intervention.

Recurrent Pulmonary Vein Stenosis After Pulmonary Vein Isolation

Department of Anesthesia, Critical Care and Pain Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA Department of Cardio-Thoracic Surgery, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands Department of Anesthesia, Peking University Peoples Hospital, Beijing, China Department of Anesthesia, Hospital México, Universidad de Costa Rica, San José, Costa Rica

Training Surgical Residents for Ultrasound-Guided Assessment and Management of Unstable Patients

OBJECTIVE Proficiency in the use of ultrasound is presently not an ACGME required core competency for accredited surgical training. There should be a basic unified ultrasound curriculum for surgical trainees. We developed a multimodal ultrasound-training program to ensure baseline proficiency and readiness for clinical performance without impacting trainee duty hours. DESIGN We developed and implemented a multimodal curriculum for ultrasound education and its use as a supplement to clinical evaluation of unstable patients. SETTING A single-center study was completed in a hospital setting. PARTICIPANTS Post-graduate year-1 surgical residents at our institution were invited to participate in a multimodal perioperative course. RESULTS 51 residents attended the course over the three sessions. The vignette exam as a whole demonstrated a Cronbachs alpha of 0.819 indicating good internal reliability of the entire test. There was significant improvement in their knowledge in clinical vignettes (55% ± 12.4 on pre-test vs. 83% ± 13.2% on post-test, p<0.001). CONCLUSION It is feasible to incorporate a focused ultrasound curriculum to assess clinically unstable patients. The multimodal nature of the course aid in the development of preclinical proficiency and decreased the orientation phase of ultrasound use.

Mechanical discordance between left atrium and left atrial appendage

During standard transesophageal echocardiographic examinations in sinus rhythm (SR) patients, the left atrial appendage (LAA) is not routinely assessed with Doppler. Despite having a SR, it is still possible to have irregular activity in the LAA. This situation is even more important for SR patients where assessment of the left atrium is often foregone. We describe a case where we encountered this situation and briefly review how to assess the left atrium and its appendage in such a case scenario.

Dynamic Three-Dimensional Geometry of the Aortic Valve Apparatus—A Feasibility Study

OBJECTIVE To provide (1) an overview of the aortic valve (AV) apparatus anatomy and nomenclature, and (2) data regarding the normal AV apparatus geometry and dynamism during the cardiac cycle obtained from three-dimensional transesophageal echocardiography (3D TEE). DESIGN Retrospective feasibility study. SETTING A single-center university teaching hospital. PARTICIPANTS The study was performed on data of 10 patients with a nonregurgitant, nonstenotic aortic valve undergoing cardiac surgery. INTERVENTIONS Intraoperative 3D TEE was performed on all the participants using the Siemens ACUSON SC2000 ultrasound system and Z6Ms transducer (Siemens Medical Systems, Mountainview, CA). MEASUREMENTS AND MAIN RESULTS Dynamic offline analyses were performed with Siemens eSie valve analytical software in a semiautomated fashion. Forty-five parameters were exported of which 13 were selected and analyzed. The cardiac cycle was divided into 4 quartiles to account for frame-rate variations. The annulus, sinus of Valsalva (SoV) and sinotubular junction (STJ) areas, diameter, perimeter and height, aortic leaflet height, leaflet coaptation height, and aortic valve-mitral valve angle changed significantly during the cardiac cycle (p < 0.001). STJ expanded more than both the annulus and the SoV (p < 0.001). The maximum aortic valve leaflet height change was greater in the left and right versus noncoronary leaflet (p < 0.001). CONCLUSIONS The semiautomated AV apparatus dynamic assessment using eSie valve software is a clinically feasible technique and can be performed readily in the operating room. It has the potential to significantly impact intraoperative decision-making in cases suitable for AV repair. The AV apparatus is a dynamic structure and demonstrates significant changes during the cardiac cycle.

Changes in Tricuspid Annular Geometry in Patients with Functional Tricuspid Regurgitation

OBJECTIVE To determine whether the indices of tricuspid annular dynamics that signify irreversible tricuspid valvular remodeling can improve surgical decision making by helping to better identify patients with functional tricuspid regurgitation who could benefit from annuloplasty. DESIGN Retrospective analysis study. SETTING Tertiary hospital. PARTICIPANTS A total number of 55 patients were selected, 18 with functional tricuspid valve (TV) regurgitation and 37 normal nonregurgitant TVs. INTERVENTIONS None. MEASUREMENTS AND MAIN RESULTS When comparing the basal, mid, and longitudinal diameters of the right ventricle between the nonregurgitant valve (NTR) group and the functional tricuspid regurgitation (FTR) group, tricuspid annulus was more dilated (p < 0.001, p = 0.001, and p = 0.006, respectively) and less nonplanar (p < 0.001) in the FTR group. At end-systole (ES), the posterolateral-anteroseptal axis was significantly greater in the FTR group than in the NTR group (mean difference = 7.15 mm; p < 0.001). The right ventricle in the FTR group was also significantly dilated with greater leaflet restriction (p = 0.015). CONCLUSIONS As compared to NTR TVs, FTR is associated with identifiable indices of tricuspid annular structural changes that are indicative of irreversible remodeling.