The Impact of Biomedical Engineering on the Development of Minimally Invasive Cardio-Thoracic Surgery

(1) We describe the boundary conditions for minimally invasive cardiac surgery (MICS) with the aim to reduce procedure-related patient injury and discomfort. (2) The analysis of the MICS work process and its demand for improved tools and devices is followed by a description of the relevant sub-specialties of bio-medical engineering: electronics, biomechanics, and materials sciences. (3) Innovations can represent a desired adaptation of an existing work process or a radical redesign of procedure and devices such as in transcutaneous procedures. Focused interaction between engineers, industry, and surgeons is always mandatory (i.e., a therapeutic alliance for addressing ‘unmet patient or professional needs’. (4) Novel techniques in MICS lean heavily on usability and safe and effective use in dedicated hands. Therefore, the use of training and simulation models should enable skills selection, a safe learning curve, and maintenance of proficiency. (5) The critical technical steps and cost–benefit trade-offs during the journey from invention to application will be explained. Business considerations such as time-to-market and returns on investment do shape the cost–benefit room for commercial use of technology. Proof of clinical safety and effectiveness by physicians remains important, but establishing the technical reliability of MICS tools and warranting appropriate surgical skills come first

At the Crossroads of Minimally Invasive Mitral Valve Surgery—Benching Single Hospital Experience to a National Registry: A Plea for Risk Management Technology

Almost 30 years after the first endoscopic mitral valve repair, Minimally Invasive Mitral Valve Surgery (MIMVS) has become the standard at many institutions due to optimal clinical results and fast recovery. The question that arises is can already good results be further improved by an Institutional Risk Management Performance (IRMP) system in decreasing risks in minimally invasive mitral valve surgery (MIMVS)? As of yet, there are no reports on IRMP and learning systems in the literature. (2) Methods: We described and appraised our five-year single institutional experience with MIMVS in isolated valve surgery included in the Netherlands Heart Registry (NHR) and investigated root causes of high-impact complications. (3) Results: The 120-day and 12-month mortality were 1.1% and 1.9%, respectively, compared to the average of 4.3% and 5.3% reported in the NHR. The regurgitation rate was 1.4% compared to 5.2% nationwide. The few high-impact complications appeared not to be preventable. (4) Discussion: In MIMVS, freedom from major and minor complications is a strong indicator of an effective IRMP but remains concealed from physicians and patients, despite its relevance to shared decision making. Innovation adds to the complexity of MIMVS and challenges surgical competence. An IRMP system may detect and control new risks earlier. (5) Conclusion: An IRMP system contributes to an effective reduction of risks, pain and discomfort; provides relevant input for shared decision making; and warrants the safe introduction of new technology. Crossroads conclusions: investment in machine learning and AI for an effective IRMP system is recommended and the roles for commanding and operating surgeons should be considered

Device induced deformation, damage, and puncture of arterial porcine tissue

An aspect of intravascular medical procedures is the navigation to optimally position the device, while avoiding tissue damage. If the conditions under which tissue damage occurs are known, this can be used to improve the device design. In vascular surgery, knowledge of a threshold force to prevent tissue damage helps to improve patient safety during the procedure. In this study, the threshold force at which a medical device punctures a vessel wall is measured. The measured force and device geometry are used to analyse local deformations and stress values using a finite element model. The tissue is described using the model developed and characterized in [1]. The purpose of this study is to find a relation between device geometry and the threshold force to avoid tissue damage for use in device design optimization. The experimental set-up consists of a displacement-controlled holder for the medical device. A porcine artery is pre-strained to physiological conditions, with a soft substrate as support to mimic surrounding tissue. The force exerted by the device is measured. Fig. 1 shows a schematic of the set-up and the artery. The arterial tissue model developed in [1] is implemented into a finite element code through a user subroutine. It includes the observed loading/unloading hysteresis in arterial tissue using an internal damage variable.The experimentally obtained force as a function of time (at constant speed) in Fig 2. is in qualitative agreement with results obtained in [2]. The threshold force at which the tissue is punctured by the medical device can be extracted. The local stress and internal damage levels at the threshold force for an unstressed vessel wall on a substrate can be analysed with a 2D plane strain FEM model (Fig. 2). An experimental and numerical procedure have been developed to analyse device-induced tissue damage. As a next step, device tip geometries, substrates and angles of approach will be varied. Results will be used to optimize device design for minimal risk on tissue damage