Petr Symersky

Comparison of multidetector-row computed tomography to echocardiography and fluoroscopy for evaluation of patients with mechanical prosthetic valve obstruction.

For evaluation of prosthetic heart valve obstruction echocardiography and fluoroscopy provide primarily functional information but may not unequivocally establish the cause of dysfunction. Our objective was to evaluate whether multidetector-row computed tomographic (MDCT) imaging could detect the morphologic substrate for such functional abnormalities. Thirteen patients with 15 prosthetic valves, in whom prosthetic valve obstruction was suspected from echocardiography or fluoroscopy but no sufficient cause could be found, underwent electrocardiographically gated multidetector-row computed tomography. MDCT data were retrospectively reconstructed at every 10% of the electrocardiographic interval and analyzed using multiplanar reformatting in anatomically adapted planes. MDCT images were evaluated for morphologic prosthetic and periprosthetic abnormalities. Results could be compared to intraoperative findings or autopsy in 7 patients. Multidetector-row computed tomography disclosed a morphologic substrate for obstruction in 8 of 13 patients. MDCT findings compatible with obstruction were confirmed at surgery or autopsy in 6 patients. In a seventh patient, incomplete leaflet closure found with multidetector-row computed tomography was confirmed at surgery. The most commonly identified causes for obstruction were subprosthetic tissue (6 patients) and abnormal anatomic orientation (3 patients). Despite an indication for surgery, 2 patients were not operated on due to recurrent bacteremias and prohibitive co-morbidity. Multidetector-row computed tomography detected leaflet motion restriction in 7 patients compared to 4 by fluoroscopy. Confirmation of leaflet restriction was available in 5 patients. Multidetector-row computed tomography missed a periprosthetic leak. In conclusion, this initial experience demonstrates that multidetector-row computed tomography can identify causes of prosthetic valve obstruction that constitute indications for surgery but are missed at echocardiography or fluoroscopy.

Prosthetic heart valve assessment with multidetector-row CT: imaging characteristics of 91 valves in 83 patients

ObjectivesMultidetector CT (MDCT) has shown potential for prosthetic heart valve (PHV) assessment. We assessed the image quality of different PHV types to determine which valves are suitable for MDCT evaluation.MethodsAll ECG-gated CTs performed in our institutions since 2003 were reviewed for the presence of PHVs. After reconstruction in 3 specific PHV planes, image quality of the supravalvular, perivalvular, subvalvular and valvular regions was scored on a four-point scale (1 = non-diagnostic, 2 = moderate, 3 = good and 4 = excellent) by two independent observers.ResultsEighty-four CT examinations (66 cardiac, 18 limited-dose aortic protocols) of 83 patients with a total of 91 PHVs in the aortic (n = 71), mitral (n = 17), pulmonary (n = 1) and tricuspid (n = 2) position were included. CT was performed on a 16-slice (n = 4), 64-slice (n = 28) or 256-slice (n = 52) MDCT system. Median image quality scores for the supra-, peri- and subvalvular regions and valvular detail were (3.5, 3.3, 3.5 and 3.5, respectively) for bileaflet PHV; (3.0, 3.0, 3.5 and 3.0, respectively) for Medtronic Hall PHV; (1.0, 1.0, 1.0 and 1.0, respectively) for Björk-Shiley and Sorin monoleaflet PHV and (3.5, 3.5, 4.0 and 2.0 respectively) for biological PHV.ConclusionCurrently implanted PHVs have good image quality on MDCT and are suitable for MDCT evaluation.

Diagnostic evaluation of left-sided prosthetic heart valve dysfunction

Prosthetic heart valve (PHV) dysfunction is a rare, but potentially life-threatening, complication. In clinical practice, PHV dysfunction poses a diagnostic dilemma. Echocardiography and fluoroscopy are the imaging techniques of choice and are routinely used in daily practice. However, these techniques sometimes fail to determine the specific cause of PHV dysfunction, which is crucial to the selection of the appropriate treatment strategy. Multidetector-row CT (MDCT) can be of additional value in diagnosing the specific cause of PHV dysfunction and provides valuable complimentary information for surgical planning in case of reoperation. Cardiac magnetic resonance imaging (CMR) has limited value in the evaluation of biological PHV dysfunction. In this Review, we discuss the use of established imaging modalities for the detection of left-sided mechanical and biological PHV dysfunction and discuss the complementary role of MDCT in this context.

Multimodality Imaging Assessment of Prosthetic Heart Valves

Echocardiography and fluoroscopy are the main techniques for prosthetic heart valve (PHV) evaluation, but because of specific limitations they may not identify the morphological substrate or the extent of PHV pathology. Cardiac computed tomography (CT) and magnetic resonance imaging (MRI) have emerged as new potential imaging modalities for valve prostheses. We present an overview of the possibilities and pitfalls of CT and MRI for PHV assessment based on a systematic literature review of all experimental and patient studies. For this, a comprehensive systematic search was performed in PubMed and Embase on March 24, 2015, containing CT/MRI and PHV synonyms. Our final selection yielded 82 articles on surgical valves. CT allowed adequate assessment of most modern PHVs and complemented echocardiography in detecting the obstruction cause (pannus or thrombus), bioprosthesis calcifications, and endocarditis extent (valve dehiscence and pseudoaneurysms). No clear advantage over echocardiography was found for the detection of vegetations or periprosthetic regurgitation. Whereas MRI metal artifacts may preclude direct prosthesis analysis, MRI provided information on PHV-related flow patterns and velocities. MRI demonstrated abnormal asymmetrical flow patterns in PHV obstruction and allowed prosthetic regurgitation assessment. Hence, CT shows great clinical relevance as a complementary imaging tool for the diagnostic work-up of patients with suspected PHV obstruction and endocarditis. MRI shows potential for functional PHV assessment although more studies are required to provide diagnostic reference values to allow discrimination of normal from pathological conditions.

Reduced force of diaphragm muscle fibers in patients with chronic thromboembolic pulmonary hypertension

Patients with pulmonary hypertension (PH) suffer from inspiratory muscle weakness. However, the pathophysiology of inspiratory muscle dysfunction in PH is unknown. We hypothesized that weakness of the diaphragm, the main inspiratory muscle, is an important contributor to inspiratory muscle dysfunction in PH patients. Our objective was to combine ex vivo diaphragm muscle fiber contractility measurements with measures of in vivo inspiratory muscle function in chronic thromboembolic pulmonary hypertension (CTEPH) patients. To assess diaphragm muscle contractility, function was studied in vivo by maximum inspiratory pressure (MIP) and ex vivo in diaphragm biopsies of the same CTEPH patients (N = 13) obtained during pulmonary endarterectomy. Patients undergoing elective lung surgery served as controls (N = 15). Muscle fiber cross-sectional area (CSA) was determined in cryosections and contractility in permeabilized muscle fibers. Diaphragm muscle fiber CSA was not significantly different between control and CTEPH patients in both slow-twitch and fast-twitch fibers. Maximal force-generating capacity was significantly lower in slow-twitch muscle fibers of CTEPH patients, whereas no difference was observed in fast-twitch muscle fibers. The maximal force of diaphragm muscle fibers correlated significantly with MIP. The calcium sensitivity of force generation was significantly reduced in fast-twitch muscle fibers of CTEPH patients, resulting in a ∼40% reduction of submaximal force generation. The fast skeletal troponin activator CK-2066260 (5 μM) restored submaximal force generation to levels exceeding those observed in control subjects. In conclusion, diaphragm muscle fiber contractility is hampered in CTEPH patients and contributes to the reduced function of the inspiratory muscles in CTEPH patients.

Transapical JenaValve in a degenerated Freedom SOLO bioprosthesis.

Degeneration of an aortic bioprosthesis is a complication often requiring high-risk surgical reintervention. Transcatheter aortic valve implantation (TAVI) provides an alternative to high-risk surgery. However, TAVI for a degenerated stentless bioprosthesis becomes more perilous because of the lack of support of a stent and the changed landmarks of the aortic root. Furthermore, the supraannular implantation technique for the stentless Freedom SOLO (Sorin Group, Milan, Italy) bioprosthesis may increase the risk for coronary occlusion after deployment because of the reduced distance between the neoannulus and the coronary ostia. In this setting, the use of the JenaValve (JenaValve Technology, GmbH,M€unchen, Germany) could reduce the risk of coronary ostium obstruction because of the specific design of this device. To illustrate this clinical problem, we present the first reported case after successful transcatheter valve-in-valve implantation of a JenaValve in a degenerated Freedom SOLO.

Multidetector-row Computed Tomography Allows Accurate Measurement of Mechanical Prosthetic Heart Valve Leaflet Closing Angles Compared With Fluoroscopy

Purpose The purpose of this study was to compare multidetector-row computed tomography (MDCT) leaflet restriction measurements with fluoroscopy measurements in commonly used mechanical prosthetic heart valves (PHVs). Methods Four mechanical PHVs (ON-X, Carbomedics, St. Jude, and Medtronic Hall) were imaged in a pulsatile model using fluoroscopy and 64–detector-row computed tomography. Five image acquisitions of each PHV without (1) and with (4) restricted leaflet closure were made. Three observers measured closure angles on fluoroscopy and MDCT. Data were analyzed using intraclass correlation coefficient (ICC) and Bland-Altman plots. Results Interobserver agreement was high in restricted and non-restricted leaflets on both modalities (ICCs >0.995). MDCT and fluoroscopy showed high agreements (ICCs >0.989). Median MDCT closure angle measurements differed at most −2 to +2 degrees from fluoroscopy in the restricted and −1 to +2 degrees in the non-restricted leaflets. Conclusions MDCT allows measurement of leaflet motion with a maximal median discrepancy of 2 degrees. Both MDCT and fluoroscopy detect restricted leaflet closure with great accuracy.

Feasibility of 3-dimensional video-assisted thoracic surgery (3D-VATS) for pulmonary resection

BackgroundTwo-dimensional video-assisted thoracic surgery (2D-VATS) has gained its position in daily practise. Although very useful, its two-dimensional view has its drawbacks when performing pulmonary resections. We report our first experience with 3-dimensional video-assisted surgery (3D-VATS). Advantages and differences with 2D-VATS and robotic surgery (RS) are discussed.MethodsTo evaluate feasibility, we scheduled patients for surgery by 3D-VATS who would normally be treated with 2D-VATS. The main difference of the equipment in 3D-VATS compared with former VATS equipment, is the flexible camera-tip (100-degrees) and the necessary 3D-glasses.ResultsFour patients were successfully operated for anatomic pulmonary resections. On-the-structure dissection was easily performed and with the flexible camera-tip, a perfect view can be obtained, with clear visualisation of important (hilar) structures. These features highly facilitate the surgeon in tissue preparation and recognition of the dissection planes.ConclusionIn our opinion, 3D-VATS is superior to 2D-VATS for performing anatomic pulmonary resection and we expect an improvement in terms of operation time and learning curve. Furthermore, it is a valuable alternative for RS at lower costs.

Unusual complication after infective endocarditis: pseudo-aneurysm of the left ventricle

A 37-year-old female, with a history of drug abuse (including cocaine), was admitted with fever and malaise. Transoesophageal echocardiography demonstrated infective endocarditis of the native mitral valve, and the patient underwent antibiotic treatment for 6 weeks. On 1 year follow-up trans-thoracic echocardiography, a large cavity with flow adjacent to the left ventricle was seen …

Quadruple Valve Replacement Visualization With 256-Slice Computed Tomography

![Figure][1] [![Graphic][3] ][3][![Graphic][4] ][4] A 51-year-old woman who had undergone aortic, mitral, and tricuspid replacement 9 years previously was admitted for aortic prosthetic obstruction, degeneration of the tricuspid bioprosthesis, and severe pulmonary regurgitation.