Robotic totally endoscopic coronary artery bypass: A word of caution implicated by a five-year follow-up

ObjectiveRobotic totally endoscopic coronary artery bypass of the left anterior descending artery has been introduced in the clinical setting using a wrist-enhanced computer-assisted device to provide a minimally invasive therapeutic approach. Early clinical results were focused on the initial hospital course of patients. This report describes the first 5-year follow-up of patients after totally endoscopic coronary artery bypass in a single center.MethodsFrom May 1999 to June 2001, 41 patients (36 male, 5 female; mean age 60.6 ± 8.9 years) underwent totally endoscopic coronary artery bypass for isolated high-grade lesions of the left anterior descending coronary artery by means of the da Vinci system (Intuitive Surgical, Inc, Mountain View, Calif). Clinical follow-up was performed 5 years after the operation. End points of the follow-up were freedom from major adverse events such as death, myocardial infarction, and repeated revascularization of the left anterior descending artery.ResultsHospital survival was 100%. Overall survival after 5 years was 92.7% (38/41 patients). Three (7.3%) patients died of noncardiac causes. Freedom from reintervention of the left anterior descending artery after a mean of 69 ± 7.4 months was 87.2% (36/41 patients). Freedom from any major adverse events during the whole follow-up was 75.7% (31/41 patients).ConclusionEndoscopic surgery on the beating heart remains the ultimate goal for minimally invasive coronary artery surgery. The clinical outcomes and need for reintervention of the target vessel leave room for improvement and may be considered reflective of early experiences typically associated with dramatic departure from conventional therapy. Moving forward, advances in instrumentation and anastomotic technology seem to be essential for reproducible and reliable coronary anastomosis in a totally endoscopic approach

Design of Hardware Accelerators for Optimized and Quantized Neural Networks to Detect Atrial Fibrillation in Patch ECG Device with RISC-V

Atrial Fibrillation (AF) is one of the most common heart arrhythmias. It is known to cause up to 15% of all strokes. In current times, modern detection systems for arrhythmias, such as single-use patch electrocardiogram (ECG) devices, have to be energy efficient, small, and affordable. In this work, specialized hardware accelerators were developed. First, an artificial neural network (NN) for the detection of AF was optimized. Special attention was paid to the minimum requirements for the inference on a RISC-V-based microcontroller. Hence, a 32-bit floating-point-based NN was analyzed. To reduce the silicon area needed, the NN was quantized to an 8-bit fixed-point datatype (Q7). Based on this datatype, specialized accelerators were developed. Those accelerators included single-instruction multiple-data (SIMD) hardware as well as accelerators for activation functions such as sigmoid and hyperbolic tangents. To accelerate activation functions that require the e-function as part of their computation (e.g., softmax), an e-function accelerator was implemented in the hardware. To compensate for the losses of quantization, the network was expanded and optimized for run-time and memory requirements. The resulting NN has a 7.5% lower run-time in clock cycles (cc) without the accelerators and 2.2 percentage points (pp) lower accuracy compared to a floating-point-based net, while requiring 65% less memory. With the specialized accelerators, the inference run-time was lowered by 87.2% while the F1-Score decreased by 6.1 pp. Implementing the Q7 accelerators instead of the floating-point unit (FPU), the silicon area needed for the microcontroller in 180 nm-technology is below 1 mm²

Pushing the limits—further evolutions of transcatheter valve procedures in the mitral position, including valve-in-valve, valve-in-ring, and valve-in-native-ring

ObjectiveTranscatheter heart valve (THV) procedures are constantly evolving. We report our experience with valve-in-valve, valve-in-ring, and direct-view valve-in-native-ring implantation in the mitral position.MethodsFourteen patients undergoing THV implantation in the mitral position were included. Clinical and postoperative data, including echocardiography and further follow-up, were analyzed.ResultsTen valve-in-valve and 2 valve-in-ring procedures were successfully performed using the transapical access route. For the third valve-in-ring procedure we used an antegrade left-atrial access via right anterolateral minithoracotomy. In 1 patient surgical mitral valve replacement was planned. Intraoperatively, the annulus appeared severely calcified and regular implantation of a bioprosthesis was not possible. As a last resort, a 29-mm Sapien XT valve (Edwards Lifesciences Inc, Irvine, Calif) was implanted under direct view. The initial result was satisfactory, but on the first postoperative day relevant paravalvular regurgitation occurred. Subsequently, the valve was fixed to an atrial cuff by 1 running suture. In this series 27-, 29-, and 31-mm bioprostheses and 28- and 30-mm annuloplasty rings were treated with 26- or 29-mm Sapien XT valves. Postoperative echocardiography on day 10 and after 6 weeks revealed good prosthesis function in all cases. In 2 valve-in-valve patients who solely received anticoagulation therapy with acetylsalicylic acid, signs of beginning valve thrombosis occurred after 8 weeks and 3 months, respectively. During further course, valve function was normalized using warfarin therapy.ConclusionsOur results demonstrate feasibility of valve-in-valve and valve-in-ring THV procedures in the mitral position. Permanent anticoagulation therapy with warfarin seems to be necessary to prevent valve dysfunction. THV implantation in a calcified native mitral ring for bailout seems not to be reproducible and thus cannot be recommended

Sutureless and rapid deployment implantation in bicuspid aortic valve: results from the sutureless and rapid-deployment aortic valve replacement international registry.

Background Benefits of sutureless and rapid deployment (SURD) bioprostheses in bicuspid aortic valves (BAV) are controversial. The aim of this study is to report the outcomes of patients undergoing aortic valve replacement (AVR) for BAV from the Sutureless and Rapid-Deployment Aortic Valve Replacement International Registry (SURD-IR). Methods Of the 4,636 patients who received primary isolated SURD-AVR between 2007 and 2018, 191 (4.1%) BAV patients underwent AVR with SURD valve. Results Overall 30-day mortality was 1.6%. The Intuity valve was implanted in 53.9% of cases, whereas the Perceval was implanted in 46.1%. Rate of stroke for isolated AVR was 4.2%. No case of endocarditis, thromboembolism, myocardial infarction, valve dislocation or structural valve deterioration was reported in the early phase. Rate of pacemaker implantation and moderate-severe aortic regurgitation (AR) were 7.9% and 3.7%, respectively. Conclusions BAV is not considered a contraindication for the implantation of SURD valves. However, detailed information of aortic root geometry as well as the knowledge of some technical considerations are mandatory for a good outcome

Austrian syndrome in the context of a fulminant pneumococcal native valve endocarditis

This is the case of a young male suffering from Austrian syndrome, which is the triad of endocarditis, meningitis, and pneumonia due to invasive S. pneumoniae infection. He reported recurrent fever for six months without any antibiotic treatment, which may have determined the further course of the syndrome. Echocardiography revealed massive native valve endocarditis, and the patient was considered for ultima-ratio cardiac surgery. Intraoperative aspect presented extensive affection of the aortic root with full destruction of aortic valve, mitral valve, and aortomitral continuity. The myocardium showed a phlegmonlike infiltration. Microbiologic testing of intraoperatively collected specimens identified penicillin-sensitive Streptococcus pneumoniae. S. pneumoniae is a very uncommon cause for infective infiltrative endocarditis and is associated with severe clinical courses. Austrian syndrome is even more rare, with only a few reported cases worldwide. In those patients, only early diagnosis, immediate antibiotic treatment, and emergent cardiac surgery can save lives

Fully integrated sensor electronics for inductive proximity switches operating up to 250 °C

In this paper we present an integrated circuit for inductive proximity switches which requires very few external components and can operate under ambient temperatures up to 250 °C. The sensor system is realized in the Fraunhofer IMS H035 technology which was specifically developed for high temperature operation. The core of the circuit is built of an oscillator which is equipped with a peak detector and readout electronics for threshold detection, references and voltage regulators to provide the necessary internal voltages as well as extensive trimming capabilities to compensate for temperature effects. The circuit can be operated from a single dc-voltage supply from 12 to 35 Volts. Calibration data can be stored in an internal EEPROM. Switching distance and hysteresis are programmable for adapting the circuit to a wide range of different detector coils and sensor geometries. Two output signals are provided that can be independently set to function as push/pull or single ended switches with programmable polarity. The only external components required are blocking capacitors for supply voltage stabilization and the LC resonator circuitry. Reverse polarity protection and special high temperature ESD and clamping structures are also fully integrated on the silicon die