Publications by authors named "Hans H Sievers"

Importance: There is no ideal valve substitute for young adults requiring aortic valve replacement. Multicenter data supporting use of the Ross procedure with respect to long-term postoperative valve-related mortality and reintervention, as well as function of the autograft and pulmonary homograft, are needed.

Objective: To determine the long-term clinical and echocardiographic outcomes in young and middle-aged patients undergoing the Ross procedure.

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Dilatation of the ascending aorta is a common occurrence in patients with bicuspid aortic valve (BAV). The aim of the current study was to characterize collagen content in advanced glycation end products (AGEs) of dilated aortic tissue from two distinct areas, concave and convex aortic sites in patients with BAV and TAV. Collagen contents extracted from 100 mg tissue was isolated by enzymatic digestion using pepsin and the nondigested material was further digested using cyanogen bromide, insoluble collagen fraction (ICF) was extracted by hydrochloric acid hydrolysis.

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Background: The purpose of this study was to evaluate the single-center experience in initial femoral versus central cannulation of the extracorporeal circulation for acute aortic dissection type A (AADA).

Methods: Between January 2003 and December 2015, 235 patients underwent repair of AADA. All patients were evaluated for the type of arterial cannulation (femoral vs.

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Background: Vein graft disease is a major and yet unsolved problem in cardiac revascularization surgery. Although accumulation of extracellular matrix is characteristic for vein graft disease, detailed analysis of the fibrotic material is lacking. Because alterations of collagen cross-links are typical for organ fibrosis, we performed a comprehensive analysis of collagen and elastin in vein graft disease.

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Background: The Ross operation provides the advantage of growth potential of the pulmonary autograft in the aortic position. However, development of autograft dilatation and regurgitation may occur. We sought to assess the progression of autograft diameters and aortic regurgitation (AR) with regard to patient age at the time of the Ross operation.

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Objectives: Since blood flow impairment by aortic valve prosthesis is characteristically dynamic, this dynamic component is best and thoroughly appreciated by exercise Doppler echocardiography. We sought to determine the haemodynamics of a new pericardial aortic bioprosthesis [Trifecta™-aortic valve bioprosthesis (T-AVB), St Jude Medical, MN, USA] at rest and during exercise and a 10-min recovery period in comparison with alternative aortic valve prostheses, e.g.

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Aims. Dysregulated expression of the endothelial nitric oxide synthase (eNOS) is observed in aortic aneurysms associated with bicuspid aortic valve (BAV). We determined eNOS protein levels in various areas in ascending aortic aneurysms.

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Background And Aim Of The Study: Marfan patients with aortic root aneurysm are typically treated with the Bentall procedure, though aortic valve-sparing procedures (AVSPs) are also possible. The study aim was to compare the authors' experience with two such techniques performed at their institution, namely a reimplantation according to David (David I) and remodeling according to Yacoub.

Methods: Between 1996 and 2009, a total of 37 Marfan patients underwent an AVSP at the authors' institution.

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Our aim is to investigate the elevation of matrix proteins in tissues obtained from distal, above the sinotubular junction (proximal), concave, and convex sites of aneurysms in the ascending aorta using a simultaneous multiplex protein detection system. Tissues were collected from 41 patients with ascending aortic aneurysms. A total of 31 patients had a bicuspid aortic valve (BAV), whereas 10 had a tricuspid aortic valve (TAV).

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The high mobility group AT-hook 2 (HMGA2) gene is proposed to regulate the genes involved in the epithelial-mesenchymal transition (EMT). One form of EMT is endothelial-mesenchymal transition (EndMT). We analyzed the expression profile of the HMGA2 gene in different human aortic diseases.

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Article Synopsis
  • The study analyzes cardiac and cerebrovascular events in patients who underwent the Ross procedure, utilizing data from the German-Dutch Ross registry to inform medical professionals and patients alike.
  • A total of 1,620 patients were evaluated, with findings indicating low early and late mortality rates, and high rates of freedom from reoperation on the autograft or pulmonary conduit over 1, 5, and 10 years.
  • The study concludes that the Ross procedure is a valid treatment for aortic valve disease but highlights the importance of recognizing factors like preoperative aortic regurgitation and the nonreinforced technique as risks for autograft failure.
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Background And Aim Of The Study: Bicuspid aortic valve (BAV), the most common form of congenital heart disease, is a leading cause of aortic stenosis (AS) and aortic insufficiency (AI). AS is typically caused by calcific valve disease. Recently, microRNAs (miRNAs) have been shown to modulate gene expression.

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Objectives: The Ross operation in the setting of a bicuspid aortic valve (BAV) remains controversial. Using data from the German Ross Registry, we sought to investigate the effect of the presence of a BAV on autograft function and diameters over time after the Ross operation compared with the presence of a tricuspid aortic valve (TAV).

Methods: A total of 1277 patients (mean age 42.

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Objective: During the past decade the Ross procedure using the full root has become the predominant surgical technique. However, progressive autograft dilatation and eventual failure remain a concern. Here we report on the surgical techniques and results of the subcoronary technique over a 14-year period.

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Background: For children who require aortic valve replacement, the pulmonary autograft may be the ideal substitute. However, re-operations for conduit exchange in the pulmonary position are inevitable. In addition, re-operations on the autograft may be necessary due to dilatation and neo-aortic insufficiency.

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Experimental valveless muscular blood pumps (biomechanical hearts) in goats can pump more than 1 L.min(-1), but due to a high pendulum volume, no significant flow contribution to the circulation is gained. Thus valved and valveless biomechanical hearts were compared for efficacy.

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Objective: The use of stentless bioprostheses for aortic valve replacement provides excellent haemodynamics; however, these valves bear the potential risk of progressive regurgitation over time. To overcome this disadvantage, a new generation of pericardial stentless prostheses has been developed. This study aims to assess the tolerance of such bioprotheses against progressive sinotubular junction dilatation.

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