Background And Aim Of The Study: Due to an asymmetrical/eccentric flow profile at the level of the aortic valve, there is an optimal orientation for each aortic valve design. This study evaluates intraoperative flow dynamics (turbulence and pressure gradient) and follow up results (pressure gradient and left ventricular mass regression) for Medtronic Hall tilting disc (MH) and St. Jude Medical bileaflet (SJM) valves, with both valves in their optimum orientation as defined in previous animal experiments.
Methods: In a randomized prospective study, MH and SJM valves (size > or = 23 mm) were implanted in their optimum orientation in 24 patients with aortic stenosis. Turbulence measurements were performed intraoperatively via a perivascular ultrasound transducer; Reynold's normal stress (RNS) values were calculated as key markers for turbulent stresses. Transvalvular pressure gradients, interventricular septum and posterior wall thickness were measured by transesophageal echocardiography intraoperatively and six months postoperatively.
Results: Mean valve size was 23.8 mm in both groups. Intraoperative RNS values (MH 7.5 +/- 2.2 N/m2 versus SJM 9.8 +/- 2.3 N/m2) and pressure gradients (MH 10.0 +/- 2.6 mmHg versus SJM 20.0 +/- 3.4 mmHg) were significantly lower for the tilting disc valve. At six months follow up, pressure gradients were reduced by half for both valves (MH 5.3 +/- 1.7 mmHg; SJM 10.4 +/- 2.3 mmHg), with the difference between the valves being maintained. Left ventricular mass regression was accelerated for MH patients with regard to interventricular septum thickness.
Conclusion: Our results indicate that the tilting disc mechanism shows superior hemodynamic performance with respect to turbulence and transvalvular pressure gradients compared with the bileaflet mechanism when both valves are implanted in their optimum orientation. This led to significant acceleration of interventricular septum mass regression. The superiority of the tilting disc mechanism is more pronounced in the smaller-sized valves.
Download full-text PDF |
Source |
|---|
Publication Analysis
Top Keywords
Similar Publications
Early Patient Outcome and Left Ventricular Function After Mitral Valve Replacement Using a Tilting Disc Mechanical Valve With Total Preservation of Mitral Valvular Apparatus.
Cureus
November 2024
Internal Medicine, Shri Ram Murti Smarak Institute of Medical Sciences, Bareilly, IND.
Introduction The study aimed to retrospectively evaluate the early patient outcome and left ventricular function after mitral valve replacement with a tilting disc valve and total preservation. Patients and methods This retrospective observational study includes patients who underwent mitral valve replacement using a tilting disc valve with total preservation of mitral valvular and subvalvular apparatus from July 2021 to August 2022 at a single center. Results The data were reviewed retrospectively for age, sex, comorbidities, operating time, aortic cross-clamp time, cardiopulmonary bypass time, preoperative and postoperative left ventricular ejection fraction, mean gradient across the mitral valve, left ventricular diameter, left atrial size, atrial fibrillation, complications, mortality, and early patient outcome.
View Article and Find Full Text PDFWide-field indocyanine green fluorescein angiography findings in inferior posterior staphyloma.
Graefes Arch Clin Exp Ophthalmol
December 2024
Department of Ophthalmology, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, N-15, W-7, Kita-Ku, Sapporo, 060-8638, Japan.
Inferior posterior staphyloma (IPS) is a rare disease typically associated with tilted disc syndrome, characterized by posterior staphyloma within the inferior fundus, without pathological myopia. Subretinal fluid (SRF) occurs in about 30-40% of IPS cases. This study investigated choroidal circulation and morphological changes in IPS using widefield indocyanine green angiography (ICGA).
View Article and Find Full Text PDFAxial elongation in nonpathologic high myopia: Ocular structural changes and glaucoma diagnostic challenges.
Asia Pac J Ophthalmol (Phila)
December 2024
State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangdong Provincial Clinical Research Center for Ocular Diseases, Guangzhou, China. Electronic address:
Axial elongation continues in highly myopic adult eyes, even in the absence of pathologic changes such as posterior staphyloma or chorioretinal atrophy. This ongoing axial elongation leads to structural changes in the macular and peripapillary regions, including chorioretinal thinning, reduced vascular perfusion and optic disc tilting and rotation, among others. These alterations can affect the acquisition and interpretation of optical coherence tomography, optical coherence tomography angiography and fundus photographs, potentially introducing artifacts and diminishing the accuracy of glaucoma diagnosis in highly myopic eyes.
View Article and Find Full Text PDFAsymmetric choroidal vascular pattern in tilted disc syndrome.
Graefes Arch Clin Exp Ophthalmol
November 2024
Department of Ophthalmology, Tokyo Women's Medical University, 8-1 Kawadacho, Shinjuku-ku, Tokyo, 162-8666, Japan.
Purpose: To observe the choroidal vasculature in patients with tilted disc syndrome (TDS) using en face optical coherence tomography (OCT) and to evaluate the symmetry of the choroidal vascular pattern in the macular area.
Methods: En face OCT was performed using a Plex Elite 9000 (Zeiss) with a 12 × 12 mm image of the macula, which was flattened with retinal pigment epithelium and segmented into choroidal layers. The middle/large choroidal vessels were evaluated for vertical symmetry qualitatively by the retina specialist coauthors and quantitatively by binarization analysis of choroidal vessel density and mean vessel diameter.
A novel homozygous missense variant in causes cone dystrophy in a consanguineous Pakistani family.
Ophthalmic Genet
November 2024
Department of Zoology, Faculty of Biological and Health Sciences, Hazara University, Mansehra, Pakistan.
Background: Cone dystrophy is a heterogeneous hereditary retinal disorder with disease symptoms appearing in the late first or early second decades of life.
Methods: A consanguineous Pakistani family with three affected individuals underwent detailed clinical and genetic investigation.
Results: The proband, a 63-years old male, showed severely reduced day vision, a visual acuity of counting fingers (CF), color vision deficiency, high myopia and photophobia.
Want AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!