Automatic aorta segmentation and valve landmark detection in C-arm CT for transcatheter aortic valve implantation.

Transcatheter aortic valve implantation (TAVI) is a minimally invasive procedure to treat severe aortic valve stenosis. As an emerging imaging technique, C-arm computed tomography (CT) plays a more and more important role in TAVI on both pre-operative surgical planning (e.g.

Evaluation of precision and accuracy assessment of different 3-D surface imaging systems for biomedical purposes.

Three-dimensional (3-D) surface imaging has gained clinical acceptance, especially in the field of cranio-maxillo-facial and plastic, reconstructive, and aesthetic surgery. Six scanners based on different scanning principles (Minolta Vivid 910®, Polhemus FastSCAN™, GFM PRIMOS®, GFM TopoCAM®, Steinbichler Comet® Vario Zoom 250, 3dMD DSP 400®) were used to measure five sheep skulls of different sizes. In three areas with varying anatomical complexity (areas, 1 = high; 2 = moderate; 3 = low), 56 distances between 20 landmarks are defined on each skull.

Improvements in transcatheter aortic valve implantation outcomes in lower surgical risk patients: a glimpse into the future.

Objectives: The purpose of this study was to investigate the evolution of patient selection criteria for transcatheter aortic valve implantation (TAVI) and its impact on clinical outcomes.

Background: Anecdotal evidence suggests that patient selection for TAVI is shifting toward lower surgical risk patients. The extent of this shift and its impact on clinical outcomes, however, are currently unknown.

Transcatheter aortic valve implantation for failing surgical aortic bioprosthetic valve: from concept to clinical application and evaluation (part 2).

Objectives: This study sought to review the acute procedural outcomes of patients who underwent transcatheter aortic valve (TAV)-in-surgical aortic valve (SAV) implantation at the German Heart Center, Munich, and to summarize the existing literature on TAV-in-SAV implantation (n = 47).

Background: There are several case reports and small case series describing transcatheter aortic valve implantation for a failing surgical aortic valve bioprosthesis (TAV-in-SAV implantation).

Methods: From January 2007 to March 2011, 20 out of 556 patients underwent a TAV-in-SAV implantation at the German Heart Center Munich.

Transcatheter aortic valve implantation for failing surgical aortic bioprosthetic valve: from concept to clinical application and evaluation (part 1).

With an aging population, improvement in life expectancy, and significant increase in the use of bioprosthetic valves, structural valve deterioration will become more and more prevalent. The operative mortality for an elective redo aortic valve surgery is reported to range from 2% to 7%, but this percentage can increase to more than 30% in high-risk and nonelective patients. Because transcatheter aortic valve (TAV)-in-surgical aortic valve (SAV) implantation represents a minimally invasive alternative to conventional redo surgery, it may prove to be safer and just as effective as redo surgery.

Incidence and predictors of acute kidney injury in patients undergoing transcatheter aortic valve implantation.

Background: Acute kidney injury (AKI) can occur in up to one third of patients after surgical aortic valve replacement and can be associated with increased mortality. Little data exist, however, about the incidence, predictors, and prognostic implications of AKI after transcatheter aortic valve implantation (TAVI).

Objectives: The aim of this study was to examine the incidence, predictors, and prognostic implications of AKI after TAVI.

Automatic aorta segmentation and valve landmark detection in C-arm CT: application to aortic valve implantation.

C-arm CT is an emerging imaging technique in transcatheter aortic valve implantation (TAVI) surgery. Automatic aorta segmentation and valve landmark detection in a C-arm CT volume has important applications in TAVI by providing valuable 3D measurements for surgery planning. Overlaying 3D segmentation onto 2D real time fluoroscopic images also provides critical visual guidance during the surgery.

Minimally invasive options for failing homografts in the pulmonary position.

Homograft implantation in the pulmonary position is usually part of initial repair in congenital heart defects with dysplasia or atresia of the pulmonary valve and at the time of the Ross operation. As part of reoperations, homografts are mainly required after nonvalved right ventricular outflow tract procedures. Due to an annual increase of homograft dysfunction, replacement is inevitable.

Predictors for new-onset complete heart block after transcatheter aortic valve implantation.

Objectives: The aim of this study was to identify risk factors for new-onset atrioventricular (AV) block requiring pacemaker (PM) implantation after transcatheter aortic valve implantation (TAVI).

Background: High-grade AV block and consecutive PM implantation are frequent complications following TAVI.

Methods: For logistic regression analysis, we included 159 patients (mean age: 81 +/- 6 years, EuroSCORE: 22 +/- 13%) who underwent TAVI (n = 116 transfemoral, n = 4 via subclavian artery, n = 37 transapical, n = 2 transaortic) between June 2007 and January 2009 and who had no previously implanted PM.

LIFEBRIDGE B2T--a new portable cardiopulmonary bypass system.

The LIFEBRIDGE B2T is a new portable cardiopulmonary bypass (CPB) system designed for temporary circulatory support. The LIFEBRIDGE B2T consists of a disposable patient unit with a CPB circuit, a control, and a base unit. The system weighs 20 kg.

Cardiopulmonary bypass with physiological flow and pressure curves: pulse is unnecessary!

Objective: Advocates of pulsatile flow postulate that the flow pattern during extracorporeal circulation (ECC) should be similar to the physiological one. However, the waveforms generated by clinically used pulsatile pumps are by far different from the physiological ones. Therefore, we constructed a new computer-controlled pulsator which can provide nearly physiological perfusion patterns during ECC.

Depression of cardiovascular autonomic function is more pronounced after mitral valve surgery: evidence for direct trauma.

The analysis of baroreflex sensitivity (BRS) and heart rate variability (HRV) leads to additional insights into patients' prognosis after cardiovascular events. The following study was performed to assess the differences in the post-operative recovery of autonomic regulation after mitral valve (MV) and aortic valve (AV) surgery with a heart-lung machine. Among the 43 consecutive male patients enrolled in a prospective study, 26 underwent isolated AV surgery and 17 isolated MV surgery.

Complicated sternal dehiscence: reconstruction with plates, cables, and cannulated screws.

Sternal dehiscence after median sternotomy can be a challenging problem in case of multiple fractures or infection. For sternal refixation, the principles of rigid plate and screw osteosynthesis gained from orthopedic surgery have been recommended by several authors. We present a new system for sternal reconstruction consisting of reconstruction plates, steel cables, and cannulated screws.

Sternal reconstruction with titanium plates in complicated sternal dehiscence.

Objective: Sternal dehiscence after median sternotomy can be a challenging problem in case of multiple fractures or infection. The use of titanium plates is a promising approach for sternal reconstruction.

Methods: Titanium plate fixation was used in 15 patients (67+/-5.

Osteosynthetic thoracic stabilization after complete resection of the sternum.

We present a case of a 66-year-old diabetic patient with chronic non-healing sternum after CABG operation. After four attempts of sternum refixation within 2 years, the need of bone debridement resulted in a nearly complete loss of sternum. Finally, a mesh graft and a pectoralis muscle flap were used to bridge the sternal space.

Autonomic control in patients experiencing atrial fibrillation after cardiac surgery.

Background: Atrial fibrillation (AF) occurs in 20-40% of patients after open heart surgery and leads to an increased morbidity and prolonged hospital stay. Earlier studies have demonstrated that depressed baroreflex function predicts mortality and major arrhythmic events in patients surviving myocardial infarction. Cardiac surgery per se leads to decreased baroreflex sensitivity (BRS) and heart rate variability (HRV).

Optimization of 3-dimensional imaging of the breast region with 3-dimensional laser scanners.

The anatomic conditions of the female breast require imaging the breast region 3-dimensionally in a normal standing position for quality assurance and for surgery planning or surgery simulation. The goal of this work was to optimize the imaging technology for the mammary region with a 3-dimensional (3D) laser scanner, to evaluate the precision and accuracy of the method, and to allow optimum data reproducibility. Avoiding the influence of biotic factors, such as mobility, we tested the most favorable imaging technology on dummy models for scanner-related factors such as the scanner position in comparison with the torso and the number of scanners and single shots.